Developer's certificate of origin の訳語 #1
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DCOに対応する日本語の適切な訳語は聞いたことがありません。確かに Origin に対応する良い単語が見つからないですね。源流か、出所か... 別のアイディアとしては それでも、コミュニティにパッチを出す人は少なくとも英語がそれなりには |
この案がいいと思います。略号の DCO を付けるとより親切かもしれませんね。 これに限らず、訳語集を作るとよさそうです。ja_JP/ の下に置きましょうか? |
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kernfs_remove supported NULL kernfs_node param to bail out but revent per-fs lock change introduced regression that dereferencing the param without NULL check so kernel goes crash. This patch checks the NULL kernfs_node in kernfs_remove and if so, just return. Quote from bug report by Jirka ``` The bug is triggered by running NAS Parallel benchmark suite on SuperMicro servers with 2x Xeon(R) Gold 6126 CPU. Here is the error log: [ 247.035564] BUG: kernel NULL pointer dereference, address: 0000000000000008 [ 247.036009] #PF: supervisor read access in kernel mode [ 247.036009] #PF: error_code(0x0000) - not-present page [ 247.036009] PGD 0 P4D 0 [ 247.036009] Oops: 0000 [#1] PREEMPT SMP PTI [ 247.058060] CPU: 1 PID: 6546 Comm: umount Not tainted 5.16.0393c3714081a53795bbff0e985d24146def6f57f+ torvalds#16 [ 247.058060] Hardware name: Supermicro Super Server/X11DDW-L, BIOS 2.0b 03/07/2018 [ 247.058060] RIP: 0010:kernfs_remove+0x8/0x50 [ 247.058060] Code: 4c 89 e0 5b 5d 41 5c 41 5d 41 5e c3 49 c7 c4 f4 ff ff ff eb b2 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 0f 1f 44 00 00 41 54 55 <48> 8b 47 08 48 89 fd 48 85 c0 48 0f 44 c7 4c 8b 60 50 49 83 c4 60 [ 247.058060] RSP: 0018:ffffbbfa48a27e48 EFLAGS: 00010246 [ 247.058060] RAX: 0000000000000001 RBX: ffffffff89e31f98 RCX: 0000000080200018 [ 247.058060] RDX: 0000000080200019 RSI: fffff6760786c900 RDI: 0000000000000000 [ 247.058060] RBP: ffffffff89e31f98 R08: ffff926b61b24d00 R09: 0000000080200018 [ 247.122048] R10: ffff926b61b24d00 R11: ffff926a8040c000 R12: ffff927bd09a2000 [ 247.122048] R13: ffffffff89e31fa0 R14: dead000000000122 R15: dead000000000100 [ 247.122048] FS: 00007f01be0a8c40(0000) GS:ffff926fa8e40000(0000) knlGS:0000000000000000 [ 247.122048] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 247.122048] CR2: 0000000000000008 CR3: 00000001145c6003 CR4: 00000000007706e0 [ 247.122048] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 247.122048] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 247.122048] PKRU: 55555554 [ 247.122048] Call Trace: [ 247.122048] <TASK> [ 247.122048] rdt_kill_sb+0x29d/0x350 [ 247.122048] deactivate_locked_super+0x36/0xa0 [ 247.122048] cleanup_mnt+0x131/0x190 [ 247.122048] task_work_run+0x5c/0x90 [ 247.122048] exit_to_user_mode_prepare+0x229/0x230 [ 247.122048] syscall_exit_to_user_mode+0x18/0x40 [ 247.122048] do_syscall_64+0x48/0x90 [ 247.122048] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 247.122048] RIP: 0033:0x7f01be2d735b ``` Link: https://bugzilla.kernel.org/show_bug.cgi?id=215696 Link: https://lore.kernel.org/lkml/CAE4VaGDZr_4wzRn2___eDYRtmdPaGGJdzu_LCSkJYuY9BEO3cw@mail.gmail.com/ Fixes: 393c371 (kernfs: switch global kernfs_rwsem lock to per-fs lock) Cc: stable@vger.kernel.org Reported-by: Jirka Hladky <jhladky@redhat.com> Tested-by: Jirka Hladky <jhladky@redhat.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Minchan Kim <minchan@kernel.org> Link: https://lore.kernel.org/r/20220427172152.3505364-1-minchan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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A crash was observed in the ORC unwinder: BUG: stack guard page was hit at 000000000dd984a2 (stack is 00000000d1caafca..00000000613712f0) kernel stack overflow (page fault): 0000 [#1] SMP NOPTI CPU: 93 PID: 23787 Comm: context_switch1 Not tainted 5.4.145 #1 RIP: 0010:unwind_next_frame Call Trace: <NMI> perf_callchain_kernel get_perf_callchain perf_callchain perf_prepare_sample perf_event_output_forward __perf_event_overflow perf_ibs_handle_irq perf_ibs_nmi_handler nmi_handle default_do_nmi do_nmi end_repeat_nmi This was really two bugs: 1) The perf IBS code passed inconsistent regs to the unwinder. 2) The unwinder didn't handle the bad input gracefully. Fix the latter bug. The ORC unwinder needs to be immune against bad inputs. The problem is that stack_access_ok() doesn't recheck the validity of the full range of registers after switching to the next valid stack with get_stack_info(). Fix that. [ jpoimboe: rewrote commit log ] Signed-off-by: Dmitry Monakhov <dmtrmonakhov@yandex-team.ru> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/1650353656-956624-1-git-send-email-dmtrmonakhov@yandex-team.ru Signed-off-by: Peter Zijlstra <peterz@infradead.org>
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kvm->arch.arm_pmu is set when userspace attempts to set the first PMU attribute. As certain attributes are mandatory, arm_pmu ends up always being set to a valid arm_pmu, otherwise KVM will refuse to run the VCPU. However, this only happens if the VCPU has the PMU feature. If the VCPU doesn't have the feature bit set, kvm->arch.arm_pmu will be left uninitialized and equal to NULL. KVM doesn't do ID register emulation for 32-bit guests and accesses to the PMU registers aren't gated by the pmu_visibility() function. This is done to prevent injecting unexpected undefined exceptions in guests which have detected the presence of a hardware PMU. But even though the VCPU feature is missing, KVM still attempts to emulate certain aspects of the PMU when PMU registers are accessed. This leads to a NULL pointer dereference like this one, which happens on an odroid-c4 board when running the kvm-unit-tests pmu-cycle-counter test with kvmtool and without the PMU feature being set: [ 454.402699] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000150 [ 454.405865] Mem abort info: [ 454.408596] ESR = 0x96000004 [ 454.411638] EC = 0x25: DABT (current EL), IL = 32 bits [ 454.416901] SET = 0, FnV = 0 [ 454.419909] EA = 0, S1PTW = 0 [ 454.423010] FSC = 0x04: level 0 translation fault [ 454.427841] Data abort info: [ 454.430687] ISV = 0, ISS = 0x00000004 [ 454.434484] CM = 0, WnR = 0 [ 454.437404] user pgtable: 4k pages, 48-bit VAs, pgdp=000000000c924000 [ 454.443800] [0000000000000150] pgd=0000000000000000, p4d=0000000000000000 [ 454.450528] Internal error: Oops: 96000004 [#1] PREEMPT SMP [ 454.456036] Modules linked in: [ 454.459053] CPU: 1 PID: 267 Comm: kvm-vcpu-0 Not tainted 5.18.0-rc4 torvalds#113 [ 454.465697] Hardware name: Hardkernel ODROID-C4 (DT) [ 454.470612] pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 454.477512] pc : kvm_pmu_event_mask.isra.0+0x14/0x74 [ 454.482427] lr : kvm_pmu_set_counter_event_type+0x2c/0x80 [ 454.487775] sp : ffff80000a9839c0 [ 454.491050] x29: ffff80000a9839c0 x28: ffff000000a83a00 x27: 0000000000000000 [ 454.498127] x26: 0000000000000000 x25: 0000000000000000 x24: ffff00000a510000 [ 454.505198] x23: ffff000000a83a00 x22: ffff000003b01000 x21: 0000000000000000 [ 454.512271] x20: 000000000000001f x19: 00000000000003ff x18: 0000000000000000 [ 454.519343] x17: 000000008003fe98 x16: 0000000000000000 x15: 0000000000000000 [ 454.526416] x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000 [ 454.533489] x11: 000000008003fdbc x10: 0000000000009d20 x9 : 000000000000001b [ 454.540561] x8 : 0000000000000000 x7 : 0000000000000d00 x6 : 0000000000009d00 [ 454.547633] x5 : 0000000000000037 x4 : 0000000000009d00 x3 : 0d09000000000000 [ 454.554705] x2 : 000000000000001f x1 : 0000000000000000 x0 : 0000000000000000 [ 454.561779] Call trace: [ 454.564191] kvm_pmu_event_mask.isra.0+0x14/0x74 [ 454.568764] kvm_pmu_set_counter_event_type+0x2c/0x80 [ 454.573766] access_pmu_evtyper+0x128/0x170 [ 454.577905] perform_access+0x34/0x80 [ 454.581527] kvm_handle_cp_32+0x13c/0x160 [ 454.585495] kvm_handle_cp15_32+0x1c/0x30 [ 454.589462] handle_exit+0x70/0x180 [ 454.592912] kvm_arch_vcpu_ioctl_run+0x1c4/0x5e0 [ 454.597485] kvm_vcpu_ioctl+0x23c/0x940 [ 454.601280] __arm64_sys_ioctl+0xa8/0xf0 [ 454.605160] invoke_syscall+0x48/0x114 [ 454.608869] el0_svc_common.constprop.0+0xd4/0xfc [ 454.613527] do_el0_svc+0x28/0x90 [ 454.616803] el0_svc+0x34/0xb0 [ 454.619822] el0t_64_sync_handler+0xa4/0x130 [ 454.624049] el0t_64_sync+0x18c/0x190 [ 454.627675] Code: a9be7bfd 910003fd f9000bf3 52807ff3 (b9415001) [ 454.633714] ---[ end trace 0000000000000000 ]--- In this particular case, Linux hasn't detected the presence of a hardware PMU because the PMU node is missing from the DTB, so userspace would have been unable to set the VCPU PMU feature even if it attempted it. What happens is that the 32-bit guest reads ID_DFR0, which advertises the presence of the PMU, and when it tries to program a counter, it triggers the NULL pointer dereference because kvm->arch.arm_pmu is NULL. kvm-arch.arm_pmu was introduced by commit 46b1878 ("KVM: arm64: Keep a per-VM pointer to the default PMU"). Until that commit, this error would be triggered instead: [ 73.388140] ------------[ cut here ]------------ [ 73.388189] Unknown PMU version 0 [ 73.390420] WARNING: CPU: 1 PID: 264 at arch/arm64/kvm/pmu-emul.c:36 kvm_pmu_event_mask.isra.0+0x6c/0x74 [ 73.399821] Modules linked in: [ 73.402835] CPU: 1 PID: 264 Comm: kvm-vcpu-0 Not tainted 5.17.0 torvalds#114 [ 73.409132] Hardware name: Hardkernel ODROID-C4 (DT) [ 73.414048] pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 73.420948] pc : kvm_pmu_event_mask.isra.0+0x6c/0x74 [ 73.425863] lr : kvm_pmu_event_mask.isra.0+0x6c/0x74 [ 73.430779] sp : ffff80000a8db9b0 [ 73.434055] x29: ffff80000a8db9b0 x28: ffff000000dbaac0 x27: 0000000000000000 [ 73.441131] x26: ffff000000dbaac0 x25: 00000000c600000d x24: 0000000000180720 [ 73.448203] x23: ffff800009ffbe10 x22: ffff00000b612000 x21: 0000000000000000 [ 73.455276] x20: 000000000000001f x19: 0000000000000000 x18: ffffffffffffffff [ 73.462348] x17: 000000008003fe98 x16: 0000000000000000 x15: 0720072007200720 [ 73.469420] x14: 0720072007200720 x13: ffff800009d32488 x12: 00000000000004e6 [ 73.476493] x11: 00000000000001a2 x10: ffff800009d32488 x9 : ffff800009d32488 [ 73.483565] x8 : 00000000ffffefff x7 : ffff800009d8a488 x6 : ffff800009d8a488 [ 73.490638] x5 : ffff0000f461a9d8 x4 : 0000000000000000 x3 : 0000000000000001 [ 73.497710] x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff000000dbaac0 [ 73.504784] Call trace: [ 73.507195] kvm_pmu_event_mask.isra.0+0x6c/0x74 [ 73.511768] kvm_pmu_set_counter_event_type+0x2c/0x80 [ 73.516770] access_pmu_evtyper+0x128/0x16c [ 73.520910] perform_access+0x34/0x80 [ 73.524532] kvm_handle_cp_32+0x13c/0x160 [ 73.528500] kvm_handle_cp15_32+0x1c/0x30 [ 73.532467] handle_exit+0x70/0x180 [ 73.535917] kvm_arch_vcpu_ioctl_run+0x20c/0x6e0 [ 73.540489] kvm_vcpu_ioctl+0x2b8/0x9e0 [ 73.544283] __arm64_sys_ioctl+0xa8/0xf0 [ 73.548165] invoke_syscall+0x48/0x114 [ 73.551874] el0_svc_common.constprop.0+0xd4/0xfc [ 73.556531] do_el0_svc+0x28/0x90 [ 73.559808] el0_svc+0x28/0x80 [ 73.562826] el0t_64_sync_handler+0xa4/0x130 [ 73.567054] el0t_64_sync+0x1a0/0x1a4 [ 73.570676] ---[ end trace 0000000000000000 ]--- [ 73.575382] kvm: pmu event creation failed -2 The root cause remains the same: kvm->arch.pmuver was never set to something sensible because the VCPU feature itself was never set. The odroid-c4 is somewhat of a special case, because Linux doesn't probe the PMU. But the above errors can easily be reproduced on any hardware, with or without a PMU driver, as long as userspace doesn't set the PMU feature. Work around the fact that KVM advertises a PMU even when the VCPU feature is not set by gating all PMU emulation on the feature. The guest can still access the registers without KVM injecting an undefined exception. Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220425145530.723858-1-alexandru.elisei@arm.com
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間違えてクローズしていたようです。忘れないように再オープンします。 |
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Resource dump menu may span over more than a single page, support it. Otherwise, menu read may result in a memory access violation: reading outside of the allocated page. Note that page format of the first menu page contains menu headers while the proceeding menu pages contain only records. The KASAN logs are as follows: BUG: KASAN: slab-out-of-bounds in strcmp+0x9b/0xb0 Read of size 1 at addr ffff88812b2e1fd0 by task systemd-udevd/496 CPU: 5 PID: 496 Comm: systemd-udevd Tainted: G B 5.16.0_for_upstream_debug_2022_01_10_23_12 #1 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x57/0x7d print_address_description.constprop.0+0x1f/0x140 ? strcmp+0x9b/0xb0 ? strcmp+0x9b/0xb0 kasan_report.cold+0x83/0xdf ? strcmp+0x9b/0xb0 strcmp+0x9b/0xb0 mlx5_rsc_dump_init+0x4ab/0x780 [mlx5_core] ? mlx5_rsc_dump_destroy+0x80/0x80 [mlx5_core] ? lockdep_hardirqs_on_prepare+0x286/0x400 ? raw_spin_unlock_irqrestore+0x47/0x50 ? aomic_notifier_chain_register+0x32/0x40 mlx5_load+0x104/0x2e0 [mlx5_core] mlx5_init_one+0x41b/0x610 [mlx5_core] .... The buggy address belongs to the object at ffff88812b2e0000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 4048 bytes to the right of 4096-byte region [ffff88812b2e0000, ffff88812b2e1000) The buggy address belongs to the page: page:000000009d69807a refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88812b2e6000 pfn:0x12b2e0 head:000000009d69807a order:3 compound_mapcount:0 compound_pincount:0 flags: 0x8000000000010200(slab|head|zone=2) raw: 8000000000010200 0000000000000000 dead000000000001 ffff888100043040 raw: ffff88812b2e6000 0000000080040000 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88812b2e1e80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88812b2e1f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88812b2e1f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff88812b2e2000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88812b2e2080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== Fixes: 12206b1 ("net/mlx5: Add support for resource dump") Signed-off-by: Aya Levin <ayal@nvidia.com> Reviewed-by: Moshe Shemesh <moshe@nvidia.com> Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
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Current DP driver implementation has adding safe mode done at dp_hpd_plug_handle() which is expected to be executed under event thread context. However there is possible circular locking happen (see blow stack trace) after edp driver call dp_hpd_plug_handle() from dp_bridge_enable() which is executed under drm_thread context. After review all possibilities methods and as discussed on https://patchwork.freedesktop.org/patch/483155/, supporting EDID compliance tests in the driver is quite hacky. As seen with other vendor drivers, supporting these will be much easier with IGT. Hence removing all the related fail safe code for it so that no possibility of circular lock will happen. Reviewed-by: Stephen Boyd <swboyd@chromium.org> Reviewed-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> ====================================================== WARNING: possible circular locking dependency detected 5.15.35-lockdep torvalds#6 Tainted: G W ------------------------------------------------------ frecon/429 is trying to acquire lock: ffffff808dc3c4e8 (&dev->mode_config.mutex){+.+.}-{3:3}, at: dp_panel_add_fail_safe_mode+0x4c/0xa0 but task is already holding lock: ffffff808dc441e0 (&kms->commit_lock[i]){+.+.}-{3:3}, at: lock_crtcs+0xb4/0x124 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&kms->commit_lock[i]){+.+.}-{3:3}: __mutex_lock_common+0x174/0x1a64 mutex_lock_nested+0x98/0xac lock_crtcs+0xb4/0x124 msm_atomic_commit_tail+0x330/0x748 commit_tail+0x19c/0x278 drm_atomic_helper_commit+0x1dc/0x1f0 drm_atomic_commit+0xc0/0xd8 drm_atomic_helper_set_config+0xb4/0x134 drm_mode_setcrtc+0x688/0x1248 drm_ioctl_kernel+0x1e4/0x338 drm_ioctl+0x3a4/0x684 __arm64_sys_ioctl+0x118/0x154 invoke_syscall+0x78/0x224 el0_svc_common+0x178/0x200 do_el0_svc+0x94/0x13c el0_svc+0x5c/0xec el0t_64_sync_handler+0x78/0x108 el0t_64_sync+0x1a4/0x1a8 -> #2 (crtc_ww_class_mutex){+.+.}-{3:3}: __mutex_lock_common+0x174/0x1a64 ww_mutex_lock+0xb8/0x278 modeset_lock+0x304/0x4ac drm_modeset_lock+0x4c/0x7c drmm_mode_config_init+0x4a8/0xc50 msm_drm_init+0x274/0xac0 msm_drm_bind+0x20/0x2c try_to_bring_up_master+0x3dc/0x470 __component_add+0x18c/0x3c0 component_add+0x1c/0x28 dp_display_probe+0x954/0xa98 platform_probe+0x124/0x15c really_probe+0x1b0/0x5f8 __driver_probe_device+0x174/0x20c driver_probe_device+0x70/0x134 __device_attach_driver+0x130/0x1d0 bus_for_each_drv+0xfc/0x14c __device_attach+0x1bc/0x2bc device_initial_probe+0x1c/0x28 bus_probe_device+0x94/0x178 deferred_probe_work_func+0x1a4/0x1f0 process_one_work+0x5d4/0x9dc worker_thread+0x898/0xccc kthread+0x2d4/0x3d4 ret_from_fork+0x10/0x20 -> #1 (crtc_ww_class_acquire){+.+.}-{0:0}: ww_acquire_init+0x1c4/0x2c8 drm_modeset_acquire_init+0x44/0xc8 drm_helper_probe_single_connector_modes+0xb0/0x12dc drm_mode_getconnector+0x5dc/0xfe8 drm_ioctl_kernel+0x1e4/0x338 drm_ioctl+0x3a4/0x684 __arm64_sys_ioctl+0x118/0x154 invoke_syscall+0x78/0x224 el0_svc_common+0x178/0x200 do_el0_svc+0x94/0x13c el0_svc+0x5c/0xec el0t_64_sync_handler+0x78/0x108 el0t_64_sync+0x1a4/0x1a8 -> #0 (&dev->mode_config.mutex){+.+.}-{3:3}: __lock_acquire+0x2650/0x672c lock_acquire+0x1b4/0x4ac __mutex_lock_common+0x174/0x1a64 mutex_lock_nested+0x98/0xac dp_panel_add_fail_safe_mode+0x4c/0xa0 dp_hpd_plug_handle+0x1f0/0x280 dp_bridge_enable+0x94/0x2b8 drm_atomic_bridge_chain_enable+0x11c/0x168 drm_atomic_helper_commit_modeset_enables+0x500/0x740 msm_atomic_commit_tail+0x3e4/0x748 commit_tail+0x19c/0x278 drm_atomic_helper_commit+0x1dc/0x1f0 drm_atomic_commit+0xc0/0xd8 drm_atomic_helper_set_config+0xb4/0x134 drm_mode_setcrtc+0x688/0x1248 drm_ioctl_kernel+0x1e4/0x338 drm_ioctl+0x3a4/0x684 __arm64_sys_ioctl+0x118/0x154 invoke_syscall+0x78/0x224 el0_svc_common+0x178/0x200 do_el0_svc+0x94/0x13c el0_svc+0x5c/0xec el0t_64_sync_handler+0x78/0x108 el0t_64_sync+0x1a4/0x1a8 Changes in v2: -- re text commit title -- remove all fail safe mode Changes in v3: -- remove dp_panel_add_fail_safe_mode() from dp_panel.h -- add Fixes Changes in v5: -- to=dianders@chromium.org Changes in v6: -- fix Fixes commit ID Fixes: 8b2c181 ("drm/msm/dp: add fail safe mode outside of event_mutex context") Reported-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com> Link: https://lore.kernel.org/r/1651007534-31842-1-git-send-email-quic_khsieh@quicinc.com Signed-off-by: Rob Clark <robdclark@chromium.org>
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The calling of siw_cm_upcall and detaching new_cep with its listen_cep should be atomistic semantics. Otherwise siw_reject may be called in a temporary state, e,g, siw_cm_upcall is called but the new_cep->listen_cep has not being cleared. This fixes a WARN: WARNING: CPU: 7 PID: 201 at drivers/infiniband/sw/siw/siw_cm.c:255 siw_cep_put+0x125/0x130 [siw] CPU: 2 PID: 201 Comm: kworker/u16:22 Kdump: loaded Tainted: G E 5.17.0-rc7 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Workqueue: iw_cm_wq cm_work_handler [iw_cm] RIP: 0010:siw_cep_put+0x125/0x130 [siw] Call Trace: <TASK> siw_reject+0xac/0x180 [siw] iw_cm_reject+0x68/0xc0 [iw_cm] cm_work_handler+0x59d/0xe20 [iw_cm] process_one_work+0x1e2/0x3b0 worker_thread+0x50/0x3a0 ? rescuer_thread+0x390/0x390 kthread+0xe5/0x110 ? kthread_complete_and_exit+0x20/0x20 ret_from_fork+0x1f/0x30 </TASK> Fixes: 6c52fdc ("rdma/siw: connection management") Link: https://lore.kernel.org/r/d528d83466c44687f3872eadcb8c184528b2e2d4.1650526554.git.chengyou@linux.alibaba.com Reported-by: Luis Chamberlain <mcgrof@kernel.org> Reviewed-by: Bernard Metzler <bmt@zurich.ibm.com> Signed-off-by: Cheng Xu <chengyou@linux.alibaba.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
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When inserting a key range item (BTRFS_DIR_LOG_INDEX_KEY) while logging a directory, we don't expect the insertion to fail with -EEXIST, because we are holding the directory's log_mutex and we have dropped all existing BTRFS_DIR_LOG_INDEX_KEY keys from the log tree before we started to log the directory. However it's possible that during the logging we attempt to insert the same BTRFS_DIR_LOG_INDEX_KEY key twice, but for this to happen we need to race with insertions of items from other inodes in the subvolume's tree while we are logging a directory. Here's how this can happen: 1) We are logging a directory with inode number 1000 that has its items spread across 3 leaves in the subvolume's tree: leaf A - has index keys from the range 2 to 20 for example. The last item in the leaf corresponds to a dir item for index number 20. All these dir items were created in a past transaction. leaf B - has index keys from the range 22 to 100 for example. It has no keys from other inodes, all its keys are dir index keys for our directory inode number 1000. Its first key is for the dir item with a sequence number of 22. All these dir items were also created in a past transaction. leaf C - has index keys for our directory for the range 101 to 120 for example. This leaf also has items from other inodes, and its first item corresponds to the dir item for index number 101 for our directory with inode number 1000; 2) When we finish processing the items from leaf A at log_dir_items(), we log a BTRFS_DIR_LOG_INDEX_KEY key with an offset of 21 and a last offset of 21, meaning the log is authoritative for the index range from 21 to 21 (a single sequence number). At this point leaf B was not yet modified in the current transaction; 3) When we return from log_dir_items() we have released our read lock on leaf B, and have set *last_offset_ret to 21 (index number of the first item on leaf B minus 1); 4) Some other task inserts an item for other inode (inode number 1001 for example) into leaf C. That resulted in pushing some items from leaf C into leaf B, in order to make room for the new item, so now leaf B has dir index keys for the sequence number range from 22 to 102 and leaf C has the dir items for the sequence number range 103 to 120; 5) At log_directory_changes() we call log_dir_items() again, passing it a 'min_offset' / 'min_key' value of 22 (*last_offset_ret from step 3 plus 1, so 21 + 1). Then btrfs_search_forward() leaves us at slot 0 of leaf B, since leaf B was modified in the current transaction. We have also initialized 'last_old_dentry_offset' to 20 after calling btrfs_previous_item() at log_dir_items(), as it left us at the last item of leaf A, which refers to the dir item with sequence number 20; 6) We then call process_dir_items_leaf() to process the dir items of leaf B, and when we process the first item, corresponding to slot 0, sequence number 22, we notice the dir item was created in a past transaction and its sequence number is greater than the value of *last_old_dentry_offset + 1 (20 + 1), so we decide to log again a BTRFS_DIR_LOG_INDEX_KEY key with an offset of 21 and an end range of 21 (key.offset - 1 == 22 - 1 == 21), which results in an -EEXIST error from insert_dir_log_key(), as we have already inserted that key at step 2, triggering the assertion at process_dir_items_leaf(). The trace produced in dmesg is like the following: assertion failed: ret != -EEXIST, in fs/btrfs/tree-log.c:3857 [198255.980839][ T7460] ------------[ cut here ]------------ [198255.981666][ T7460] kernel BUG at fs/btrfs/ctree.h:3617! [198255.983141][ T7460] invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI [198255.984080][ T7460] CPU: 0 PID: 7460 Comm: repro-ghost-dir Not tainted 5.18.0-5314c78ac373-misc-next+ [198255.986027][ T7460] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014 [198255.988600][ T7460] RIP: 0010:assertfail.constprop.0+0x1c/0x1e [198255.989465][ T7460] Code: 8b 4c 89 (...) [198255.992599][ T7460] RSP: 0018:ffffc90007387188 EFLAGS: 00010282 [198255.993414][ T7460] RAX: 000000000000003d RBX: 0000000000000065 RCX: 0000000000000000 [198255.996056][ T7460] RDX: 0000000000000001 RSI: ffffffff8b62b180 RDI: fffff52000e70e24 [198255.997668][ T7460] RBP: ffffc90007387188 R08: 000000000000003d R09: ffff8881f0e16507 [198255.999199][ T7460] R10: ffffed103e1c2ca0 R11: 0000000000000001 R12: 00000000ffffffef [198256.000683][ T7460] R13: ffff88813befc630 R14: ffff888116c16e70 R15: ffffc90007387358 [198256.007082][ T7460] FS: 00007fc7f7c24640(0000) GS:ffff8881f0c00000(0000) knlGS:0000000000000000 [198256.009939][ T7460] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [198256.014133][ T7460] CR2: 0000560bb16d0b78 CR3: 0000000140b34005 CR4: 0000000000170ef0 [198256.015239][ T7460] Call Trace: [198256.015674][ T7460] <TASK> [198256.016313][ T7460] log_dir_items.cold+0x16/0x2c [198256.018858][ T7460] ? replay_one_extent+0xbf0/0xbf0 [198256.025932][ T7460] ? release_extent_buffer+0x1d2/0x270 [198256.029658][ T7460] ? rcu_read_lock_sched_held+0x16/0x80 [198256.031114][ T7460] ? lock_acquired+0xbe/0x660 [198256.032633][ T7460] ? rcu_read_lock_sched_held+0x16/0x80 [198256.034386][ T7460] ? lock_release+0xcf/0x8a0 [198256.036152][ T7460] log_directory_changes+0xf9/0x170 [198256.036993][ T7460] ? log_dir_items+0xba0/0xba0 [198256.037661][ T7460] ? do_raw_write_unlock+0x7d/0xe0 [198256.038680][ T7460] btrfs_log_inode+0x233b/0x26d0 [198256.041294][ T7460] ? log_directory_changes+0x170/0x170 [198256.042864][ T7460] ? btrfs_attach_transaction_barrier+0x60/0x60 [198256.045130][ T7460] ? rcu_read_lock_sched_held+0x16/0x80 [198256.046568][ T7460] ? lock_release+0xcf/0x8a0 [198256.047504][ T7460] ? lock_downgrade+0x420/0x420 [198256.048712][ T7460] ? ilookup5_nowait+0x81/0xa0 [198256.049747][ T7460] ? lock_downgrade+0x420/0x420 [198256.050652][ T7460] ? do_raw_spin_unlock+0xa9/0x100 [198256.051618][ T7460] ? __might_resched+0x128/0x1c0 [198256.052511][ T7460] ? __might_sleep+0x66/0xc0 [198256.053442][ T7460] ? __kasan_check_read+0x11/0x20 [198256.054251][ T7460] ? iget5_locked+0xbd/0x150 [198256.054986][ T7460] ? run_delayed_iput_locked+0x110/0x110 [198256.055929][ T7460] ? btrfs_iget+0xc7/0x150 [198256.056630][ T7460] ? btrfs_orphan_cleanup+0x4a0/0x4a0 [198256.057502][ T7460] ? free_extent_buffer+0x13/0x20 [198256.058322][ T7460] btrfs_log_inode+0x2654/0x26d0 [198256.059137][ T7460] ? log_directory_changes+0x170/0x170 [198256.060020][ T7460] ? rcu_read_lock_sched_held+0x16/0x80 [198256.060930][ T7460] ? rcu_read_lock_sched_held+0x16/0x80 [198256.061905][ T7460] ? lock_contended+0x770/0x770 [198256.062682][ T7460] ? btrfs_log_inode_parent+0xd04/0x1750 [198256.063582][ T7460] ? lock_downgrade+0x420/0x420 [198256.064432][ T7460] ? preempt_count_sub+0x18/0xc0 [198256.065550][ T7460] ? __mutex_lock+0x580/0xdc0 [198256.066654][ T7460] ? stack_trace_save+0x94/0xc0 [198256.068008][ T7460] ? __kasan_check_write+0x14/0x20 [198256.072149][ T7460] ? __mutex_unlock_slowpath+0x12a/0x430 [198256.073145][ T7460] ? mutex_lock_io_nested+0xcd0/0xcd0 [198256.074341][ T7460] ? wait_for_completion_io_timeout+0x20/0x20 [198256.075345][ T7460] ? lock_downgrade+0x420/0x420 [198256.076142][ T7460] ? lock_contended+0x770/0x770 [198256.076939][ T7460] ? do_raw_spin_lock+0x1c0/0x1c0 [198256.078401][ T7460] ? btrfs_sync_file+0x5e6/0xa40 [198256.080598][ T7460] btrfs_log_inode_parent+0x523/0x1750 [198256.081991][ T7460] ? wait_current_trans+0xc8/0x240 [198256.083320][ T7460] ? lock_downgrade+0x420/0x420 [198256.085450][ T7460] ? btrfs_end_log_trans+0x70/0x70 [198256.086362][ T7460] ? rcu_read_lock_sched_held+0x16/0x80 [198256.087544][ T7460] ? lock_release+0xcf/0x8a0 [198256.088305][ T7460] ? lock_downgrade+0x420/0x420 [198256.090375][ T7460] ? dget_parent+0x8e/0x300 [198256.093538][ T7460] ? do_raw_spin_lock+0x1c0/0x1c0 [198256.094918][ T7460] ? lock_downgrade+0x420/0x420 [198256.097815][ T7460] ? do_raw_spin_unlock+0xa9/0x100 [198256.101822][ T7460] ? dget_parent+0xb7/0x300 [198256.103345][ T7460] btrfs_log_dentry_safe+0x48/0x60 [198256.105052][ T7460] btrfs_sync_file+0x629/0xa40 [198256.106829][ T7460] ? start_ordered_ops.constprop.0+0x120/0x120 [198256.109655][ T7460] ? __fget_files+0x161/0x230 [198256.110760][ T7460] vfs_fsync_range+0x6d/0x110 [198256.111923][ T7460] ? start_ordered_ops.constprop.0+0x120/0x120 [198256.113556][ T7460] __x64_sys_fsync+0x45/0x70 [198256.114323][ T7460] do_syscall_64+0x5c/0xc0 [198256.115084][ T7460] ? syscall_exit_to_user_mode+0x3b/0x50 [198256.116030][ T7460] ? do_syscall_64+0x69/0xc0 [198256.116768][ T7460] ? do_syscall_64+0x69/0xc0 [198256.117555][ T7460] ? do_syscall_64+0x69/0xc0 [198256.118324][ T7460] ? sysvec_call_function_single+0x57/0xc0 [198256.119308][ T7460] ? asm_sysvec_call_function_single+0xa/0x20 [198256.120363][ T7460] entry_SYSCALL_64_after_hwframe+0x44/0xae [198256.121334][ T7460] RIP: 0033:0x7fc7fe97b6ab [198256.122067][ T7460] Code: 0f 05 48 (...) [198256.125198][ T7460] RSP: 002b:00007fc7f7c23950 EFLAGS: 00000293 ORIG_RAX: 000000000000004a [198256.126568][ T7460] RAX: ffffffffffffffda RBX: 00007fc7f7c239f0 RCX: 00007fc7fe97b6ab [198256.127942][ T7460] RDX: 0000000000000002 RSI: 000056167536bcf0 RDI: 0000000000000004 [198256.129302][ T7460] RBP: 0000000000000004 R08: 0000000000000000 R09: 000000007ffffeb8 [198256.130670][ T7460] R10: 00000000000001ff R11: 0000000000000293 R12: 0000000000000001 [198256.132046][ T7460] R13: 0000561674ca8140 R14: 00007fc7f7c239d0 R15: 000056167536dab8 [198256.133403][ T7460] </TASK> Fix this by treating -EEXIST as expected at insert_dir_log_key() and have it update the item with an end offset corresponding to the maximum between the previously logged end offset and the new requested end offset. The end offsets may be different due to dir index key deletions that happened as part of unlink operations while we are logging a directory (triggered when fsyncing some other inode parented by the directory) or during renames which always attempt to log a single dir index deletion. Reported-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org> Link: https://lore.kernel.org/linux-btrfs/YmyefE9mc2xl5ZMz@hungrycats.org/ Fixes: 732d591 ("btrfs: stop copying old dir items when logging a directory") Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
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We are accessing "desc->ops" in sof_pci_probe without checking "desc" pointer. This results in NULL pointer exception if pci_id->driver_data i.e desc pointer isn't defined in sof device probe: BUG: kernel NULL pointer dereference, address: 0000000000000060 PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP NOPTI RIP: 0010:sof_pci_probe+0x1e/0x17f [snd_sof_pci] Code: Unable to access opcode bytes at RIP 0xffffffffc043dff4. RSP: 0018:ffffac4b03b9b8d8 EFLAGS: 00010246 Add NULL pointer check for sof_dev_desc pointer to avoid such exception. Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com> Signed-off-by: Ajit Kumar Pandey <AjitKumar.Pandey@amd.com> Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Link: https://lore.kernel.org/r/20220426183357.102155-1-pierre-louis.bossart@linux.intel.com Signed-off-by: Mark Brown <broonie@kernel.org>
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As reported by Alan, the CFI (Call Frame Information) in the VDSO time routines is incorrect since commit ce7d805 ("powerpc/vdso: Prepare for switching VDSO to generic C implementation."). DWARF has a concept called the CFA (Canonical Frame Address), which on powerpc is calculated as an offset from the stack pointer (r1). That means when the stack pointer is changed there must be a corresponding CFI directive to update the calculation of the CFA. The current code is missing those directives for the changes to r1, which prevents gdb from being able to generate a backtrace from inside VDSO functions, eg: Breakpoint 1, 0x00007ffff7f804dc in __kernel_clock_gettime () (gdb) bt #0 0x00007ffff7f804dc in __kernel_clock_gettime () #1 0x00007ffff7d8872c in clock_gettime@@GLIBC_2.17 () from /lib64/libc.so.6 #2 0x00007fffffffd960 in ?? () #3 0x00007ffff7d8872c in clock_gettime@@GLIBC_2.17 () from /lib64/libc.so.6 Backtrace stopped: frame did not save the PC Alan helpfully describes some rules for correctly maintaining the CFI information: 1) Every adjustment to the current frame address reg (ie. r1) must be described, and exactly at the instruction where r1 changes. Why? Because stack unwinding might want to access previous frames. 2) If a function changes LR or any non-volatile register, the save location for those regs must be given. The CFI can be at any instruction after the saves up to the point that the reg is changed. (Exception: LR save should be described before a bl. not after) 3) If asychronous unwind info is needed then restores of LR and non-volatile regs must also be described. The CFI can be at any instruction after the reg is restored up to the point where the save location is (potentially) trashed. Fix the inability to backtrace by adding CFI directives describing the changes to r1, ie. satisfying rule 1. Also change the information for LR to point to the copy saved on the stack, not the value in r0 that will be overwritten by the function call. Finally, add CFI directives describing the save/restore of r2. With the fix gdb can correctly back trace and navigate up and down the stack: Breakpoint 1, 0x00007ffff7f804dc in __kernel_clock_gettime () (gdb) bt #0 0x00007ffff7f804dc in __kernel_clock_gettime () #1 0x00007ffff7d8872c in clock_gettime@@GLIBC_2.17 () from /lib64/libc.so.6 #2 0x0000000100015b60 in gettime () #3 0x000000010000c8bc in print_long_format () #4 0x000000010000d180 in print_current_files () #5 0x00000001000054ac in main () (gdb) up #1 0x00007ffff7d8872c in clock_gettime@@GLIBC_2.17 () from /lib64/libc.so.6 (gdb) #2 0x0000000100015b60 in gettime () (gdb) #3 0x000000010000c8bc in print_long_format () (gdb) #4 0x000000010000d180 in print_current_files () (gdb) #5 0x00000001000054ac in main () (gdb) Initial frame selected; you cannot go up. (gdb) down #4 0x000000010000d180 in print_current_files () (gdb) #3 0x000000010000c8bc in print_long_format () (gdb) #2 0x0000000100015b60 in gettime () (gdb) #1 0x00007ffff7d8872c in clock_gettime@@GLIBC_2.17 () from /lib64/libc.so.6 (gdb) #0 0x00007ffff7f804dc in __kernel_clock_gettime () (gdb) Fixes: ce7d805 ("powerpc/vdso: Prepare for switching VDSO to generic C implementation.") Cc: stable@vger.kernel.org # v5.11+ Reported-by: Alan Modra <amodra@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org> Link: https://lore.kernel.org/r/20220502125010.1319370-1-mpe@ellerman.id.au
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With CONFIG_FORTIFY_SOURCE enabled, string functions will also perform dynamic checks for string size which can panic the kernel, like incase of overflow detection. In papr_scm, papr_scm_pmu_check_events function uses stat->stat_id with string operations, to populate the nvdimm_events_map array. Since stat_id variable is not NULL terminated, the kernel panics with CONFIG_FORTIFY_SOURCE enabled at boot time. Below are the logs of kernel panic: detected buffer overflow in __fortify_strlen ------------[ cut here ]------------ kernel BUG at lib/string_helpers.c:980! Oops: Exception in kernel mode, sig: 5 [#1] NIP [c00000000077dad0] fortify_panic+0x28/0x38 LR [c00000000077dacc] fortify_panic+0x24/0x38 Call Trace: [c0000022d77836e0] [c00000000077dacc] fortify_panic+0x24/0x38 (unreliable) [c00800000deb2660] papr_scm_pmu_check_events.constprop.0+0x118/0x220 [papr_scm] [c00800000deb2cb0] papr_scm_probe+0x288/0x62c [papr_scm] [c0000000009b46a8] platform_probe+0x98/0x150 Fix this issue by using kmemdup_nul() to copy the content of stat->stat_id directly to the nvdimm_events_map array. mpe: stat->stat_id comes from the hypervisor, not userspace, so there is no security exposure. Fixes: 4c08d4b ("powerpc/papr_scm: Add perf interface support") Signed-off-by: Kajol Jain <kjain@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220505153451.35503-1-kjain@linux.ibm.com
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'rmmod pmt_telemetry' panics with: BUG: kernel NULL pointer dereference, address: 0000000000000040 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP NOPTI CPU: 4 PID: 1697 Comm: rmmod Tainted: G S W -------- --- 5.18.0-rc4 #3 Hardware name: Intel Corporation Alder Lake Client Platform/AlderLake-P DDR5 RVP, BIOS ADLPFWI1.R00.3056.B00.2201310233 01/31/2022 RIP: 0010:device_del+0x1b/0x3d0 Code: e8 1a d9 e9 ff e9 58 ff ff ff 48 8b 08 eb dc 0f 1f 44 00 00 41 56 41 55 41 54 55 48 8d af 80 00 00 00 53 48 89 fb 48 83 ec 18 <4c> 8b 67 40 48 89 ef 65 48 8b 04 25 28 00 00 00 48 89 44 24 10 31 RSP: 0018:ffffb520415cfd60 EFLAGS: 00010286 RAX: 0000000000000070 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000080 R08: ffffffffffffffff R09: ffffb520415cfd78 R10: 0000000000000002 R11: ffffb520415cfd78 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f7e198e5740(0000) GS:ffff905c9f700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000040 CR3: 000000010782a005 CR4: 0000000000770ee0 PKRU: 55555554 Call Trace: <TASK> ? __xa_erase+0x53/0xb0 device_unregister+0x13/0x50 intel_pmt_dev_destroy+0x34/0x60 [pmt_class] pmt_telem_remove+0x40/0x50 [pmt_telemetry] auxiliary_bus_remove+0x18/0x30 device_release_driver_internal+0xc1/0x150 driver_detach+0x44/0x90 bus_remove_driver+0x74/0xd0 auxiliary_driver_unregister+0x12/0x20 pmt_telem_exit+0xc/0xe4a [pmt_telemetry] __x64_sys_delete_module+0x13a/0x250 ? syscall_trace_enter.isra.19+0x11e/0x1a0 do_syscall_64+0x58/0x80 ? syscall_exit_to_user_mode+0x12/0x30 ? do_syscall_64+0x67/0x80 ? syscall_exit_to_user_mode+0x12/0x30 ? do_syscall_64+0x67/0x80 ? syscall_exit_to_user_mode+0x12/0x30 ? do_syscall_64+0x67/0x80 ? exc_page_fault+0x64/0x140 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f7e1803a05b Code: 73 01 c3 48 8b 0d 2d 4e 38 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa b8 b0 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d fd 4d 38 00 f7 d8 64 89 01 48 The probe function, pmt_telem_probe(), adds an entry for devices even if they have not been initialized. This results in the array of initialized devices containing both initialized and uninitialized entries. This causes a panic in the remove function, pmt_telem_remove() which expects the array to only contain initialized entries. Only use an entry when a device is initialized. Cc: "David E. Box" <david.e.box@linux.intel.com> Cc: Hans de Goede <hdegoede@redhat.com> Cc: Mark Gross <markgross@kernel.org> Cc: platform-driver-x86@vger.kernel.org Signed-off-by: David Arcari <darcari@redhat.com> Signed-off-by: Prarit Bhargava <prarit@redhat.com> Reviewed-by: David E. Box <david.e.box@linux.intel.com> Link: https://lore.kernel.org/r/20220429122322.2550003-1-prarit@redhat.com Reviewed-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
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Since commit f1131b9 ("net: phy: micrel: use kszphy_suspend()/kszphy_resume for irq aware devices") the following NULL pointer dereference is observed on a board with KSZ8061: # udhcpc -i eth0 udhcpc: started, v1.35.0 8<--- cut here --- Unable to handle kernel NULL pointer dereference at virtual address 00000008 pgd = f73cef4e [00000008] *pgd=00000000 Internal error: Oops: 5 [#1] SMP ARM Modules linked in: CPU: 0 PID: 196 Comm: ifconfig Not tainted 5.15.37-dirty torvalds#94 Hardware name: Freescale i.MX6 SoloX (Device Tree) PC is at kszphy_config_reset+0x10/0x114 LR is at kszphy_resume+0x24/0x64 ... The KSZ8061 phy_driver structure does not have the .probe/..driver_data fields, which means that priv is not allocated. This causes the NULL pointer dereference inside kszphy_config_reset(). Fix the problem by using the generic suspend/resume functions as before. Another alternative would be to provide the .probe and .driver_data information into the structure, but to be on the safe side, let's just restore Ethernet functionality by using the generic suspend/resume. Cc: stable@vger.kernel.org Fixes: f1131b9 ("net: phy: micrel: use kszphy_suspend()/kszphy_resume for irq aware devices") Signed-off-by: Fabio Estevam <festevam@denx.de> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Link: https://lore.kernel.org/r/20220504143104.1286960-1-festevam@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Function ice_plug_aux_dev() assigns pf->adev field too early prior
aux device initialization and on other side ice_unplug_aux_dev()
starts aux device deinit and at the end assigns NULL to pf->adev.
This is wrong because pf->adev should always be non-NULL only when
aux device is fully initialized and ready. This wrong order causes
a crash when ice_send_event_to_aux() call occurs because that function
depends on non-NULL value of pf->adev and does not assume that
aux device is half-initialized or half-destroyed.
After order correction the race window is tiny but it is still there,
as Leon mentioned and manipulation with pf->adev needs to be protected
by mutex.
Fix (un-)plugging functions so pf->adev field is set after aux device
init and prior aux device destroy and protect pf->adev assignment by
new mutex. This mutex is also held during ice_send_event_to_aux()
call to ensure that aux device is valid during that call.
Note that device lock used ice_send_event_to_aux() needs to be kept
to avoid race with aux drv unload.
Reproducer:
cycle=1
while :;do
echo "#### Cycle: $cycle"
ip link set ens7f0 mtu 9000
ip link add bond0 type bond mode 1 miimon 100
ip link set bond0 up
ifenslave bond0 ens7f0
ip link set bond0 mtu 9000
ethtool -L ens7f0 combined 1
ip link del bond0
ip link set ens7f0 mtu 1500
sleep 1
let cycle++
done
In short when the device is added/removed to/from bond the aux device
is unplugged/plugged. When MTU of the device is changed an event is
sent to aux device asynchronously. This can race with (un)plugging
operation and because pf->adev is set too early (plug) or too late
(unplug) the function ice_send_event_to_aux() can touch uninitialized
or destroyed fields. In the case of crash below pf->adev->dev.mutex.
Crash:
[ 53.372066] bond0: (slave ens7f0): making interface the new active one
[ 53.378622] bond0: (slave ens7f0): Enslaving as an active interface with an u
p link
[ 53.386294] IPv6: ADDRCONF(NETDEV_CHANGE): bond0: link becomes ready
[ 53.549104] bond0: (slave ens7f1): Enslaving as a backup interface with an up
link
[ 54.118906] ice 0000:ca:00.0 ens7f0: Number of in use tx queues changed inval
idating tc mappings. Priority traffic classification disabled!
[ 54.233374] ice 0000:ca:00.1 ens7f1: Number of in use tx queues changed inval
idating tc mappings. Priority traffic classification disabled!
[ 54.248204] bond0: (slave ens7f0): Releasing backup interface
[ 54.253955] bond0: (slave ens7f1): making interface the new active one
[ 54.274875] bond0: (slave ens7f1): Releasing backup interface
[ 54.289153] bond0 (unregistering): Released all slaves
[ 55.383179] MII link monitoring set to 100 ms
[ 55.398696] bond0: (slave ens7f0): making interface the new active one
[ 55.405241] BUG: kernel NULL pointer dereference, address: 0000000000000080
[ 55.405289] bond0: (slave ens7f0): Enslaving as an active interface with an u
p link
[ 55.412198] #PF: supervisor write access in kernel mode
[ 55.412200] #PF: error_code(0x0002) - not-present page
[ 55.412201] PGD 25d2ad067 P4D 0
[ 55.412204] Oops: 0002 [#1] PREEMPT SMP NOPTI
[ 55.412207] CPU: 0 PID: 403 Comm: kworker/0:2 Kdump: loaded Tainted: G S
5.17.0-13579-g57f2d6540f03 #1
[ 55.429094] bond0: (slave ens7f1): Enslaving as a backup interface with an up
link
[ 55.430224] Hardware name: Dell Inc. PowerEdge R750/06V45N, BIOS 1.4.4 10/07/
2021
[ 55.430226] Workqueue: ice ice_service_task [ice]
[ 55.468169] RIP: 0010:mutex_unlock+0x10/0x20
[ 55.472439] Code: 0f b1 13 74 96 eb e0 4c 89 ee eb d8 e8 79 54 ff ff 66 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 65 48 8b 04 25 40 ef 01 00 31 d2 <f0> 48 0f b1 17 75 01 c3 e9 e3 fe ff ff 0f 1f 00 0f 1f 44 00 00 48
[ 55.491186] RSP: 0018:ff4454230d7d7e28 EFLAGS: 00010246
[ 55.496413] RAX: ff1a79b208b08000 RBX: ff1a79b2182e8880 RCX: 0000000000000001
[ 55.503545] RDX: 0000000000000000 RSI: ff4454230d7d7db0 RDI: 0000000000000080
[ 55.510678] RBP: ff1a79d1c7e48b68 R08: ff4454230d7d7db0 R09: 0000000000000041
[ 55.517812] R10: 00000000000000a5 R11: 00000000000006e6 R12: ff1a79d1c7e48bc0
[ 55.524945] R13: 0000000000000000 R14: ff1a79d0ffc305c0 R15: 0000000000000000
[ 55.532076] FS: 0000000000000000(0000) GS:ff1a79d0ffc00000(0000) knlGS:0000000000000000
[ 55.540163] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 55.545908] CR2: 0000000000000080 CR3: 00000003487ae003 CR4: 0000000000771ef0
[ 55.553041] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 55.560173] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 55.567305] PKRU: 55555554
[ 55.570018] Call Trace:
[ 55.572474] <TASK>
[ 55.574579] ice_service_task+0xaab/0xef0 [ice]
[ 55.579130] process_one_work+0x1c5/0x390
[ 55.583141] ? process_one_work+0x390/0x390
[ 55.587326] worker_thread+0x30/0x360
[ 55.590994] ? process_one_work+0x390/0x390
[ 55.595180] kthread+0xe6/0x110
[ 55.598325] ? kthread_complete_and_exit+0x20/0x20
[ 55.603116] ret_from_fork+0x1f/0x30
[ 55.606698] </TASK>
Fixes: f9f5301 ("ice: Register auxiliary device to provide RDMA")
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Ivan Vecera <ivecera@redhat.com>
Reviewed-by: Dave Ertman <david.m.ertman@intel.com>
Tested-by: Gurucharan <gurucharanx.g@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
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Kernel panic when injecting memory_failure for the global huge_zero_page, when CONFIG_DEBUG_VM is enabled, as follows. Injecting memory failure for pfn 0x109ff9 at process virtual address 0x20ff9000 page:00000000fb053fc3 refcount:2 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x109e00 head:00000000fb053fc3 order:9 compound_mapcount:0 compound_pincount:0 flags: 0x17fffc000010001(locked|head|node=0|zone=2|lastcpupid=0x1ffff) raw: 017fffc000010001 0000000000000000 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000000000 00000002ffffffff 0000000000000000 page dumped because: VM_BUG_ON_PAGE(is_huge_zero_page(head)) ------------[ cut here ]------------ kernel BUG at mm/huge_memory.c:2499! invalid opcode: 0000 [#1] PREEMPT SMP PTI CPU: 6 PID: 553 Comm: split_bug Not tainted 5.18.0-rc1+ torvalds#11 Hardware name: Alibaba Cloud Alibaba Cloud ECS, BIOS 3288b3c 04/01/2014 RIP: 0010:split_huge_page_to_list+0x66a/0x880 Code: 84 9b fb ff ff 48 8b 7c 24 08 31 f6 e8 9f 5d 2a 00 b8 b8 02 00 00 e9 e8 fb ff ff 48 c7 c6 e8 47 3c 82 4c b RSP: 0018:ffffc90000dcbdf8 EFLAGS: 00010246 RAX: 000000000000003c RBX: 0000000000000001 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff823e4c4f RDI: 00000000ffffffff RBP: ffff88843fffdb40 R08: 0000000000000000 R09: 00000000fffeffff R10: ffffc90000dcbc48 R11: ffffffff82d68448 R12: ffffea0004278000 R13: ffffffff823c6203 R14: 0000000000109ff9 R15: ffffea000427fe40 FS: 00007fc375a26740(0000) GS:ffff88842fd80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc3757c9290 CR3: 0000000102174006 CR4: 00000000003706e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: try_to_split_thp_page+0x3a/0x130 memory_failure+0x128/0x800 madvise_inject_error.cold+0x8b/0xa1 __x64_sys_madvise+0x54/0x60 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fc3754f8bf9 Code: 01 00 48 81 c4 80 00 00 00 e9 f1 fe ff ff 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 8 RSP: 002b:00007ffeda93a1d8 EFLAGS: 00000217 ORIG_RAX: 000000000000001c RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc3754f8bf9 RDX: 0000000000000064 RSI: 0000000000003000 RDI: 0000000020ff9000 RBP: 00007ffeda93a200 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000217 R12: 0000000000400490 R13: 00007ffeda93a2e0 R14: 0000000000000000 R15: 0000000000000000 We think that raising BUG is overkilling for splitting huge_zero_page, the huge_zero_page can't be met from normal paths other than memory failure, but memory failure is a valid caller. So we tend to replace the BUG to WARN + returning -EBUSY, and thus the panic above won't happen again. Link: https://lkml.kernel.org/r/f35f8b97377d5d3ede1bc5ac3114da888c57cbce.1651052574.git.xuyu@linux.alibaba.com Fixes: d173d54 ("mm/memory-failure.c: skip huge_zero_page in memory_failure()") Fixes: 6a46079 ("HWPOISON: The high level memory error handler in the VM v7") Signed-off-by: Xu Yu <xuyu@linux.alibaba.com> Suggested-by: Yang Shi <shy828301@gmail.com> Reported-by: kernel test robot <lkp@intel.com> Reviewed-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Reviewed-by: Yang Shi <shy828301@gmail.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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The following VM_BUG_ON_FOLIO() is triggered when memory error event happens on the (thp/folio) pages which are about to be freed: [ 1160.232771] page:00000000b36a8a0f refcount:1 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x16a000 [ 1160.236916] page:00000000b36a8a0f refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x16a000 [ 1160.240684] flags: 0x57ffffc0800000(hwpoison|node=1|zone=2|lastcpupid=0x1fffff) [ 1160.243458] raw: 0057ffffc0800000 dead000000000100 dead000000000122 0000000000000000 [ 1160.246268] raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000 [ 1160.249197] page dumped because: VM_BUG_ON_FOLIO(!folio_test_large(folio)) [ 1160.251815] ------------[ cut here ]------------ [ 1160.253438] kernel BUG at include/linux/mm.h:788! [ 1160.256162] invalid opcode: 0000 [#1] PREEMPT SMP PTI [ 1160.258172] CPU: 2 PID: 115368 Comm: mceinj.sh Tainted: G E 5.18.0-rc1-v5.18-rc1-220404-2353-005-g83111+ #3 [ 1160.262049] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1.fc35 04/01/2014 [ 1160.265103] RIP: 0010:dump_page.cold+0x27e/0x2bd [ 1160.266757] Code: fe ff ff 48 c7 c6 81 f1 5a 98 e9 4c fe ff ff 48 c7 c6 a1 95 59 98 e9 40 fe ff ff 48 c7 c6 50 bf 5a 98 48 89 ef e8 9d 04 6d ff <0f> 0b 41 f7 c4 ff 0f 00 00 0f 85 9f fd ff ff 49 8b 04 24 a9 00 00 [ 1160.273180] RSP: 0018:ffffaa2c4d59fd18 EFLAGS: 00010292 [ 1160.274969] RAX: 000000000000003e RBX: 0000000000000001 RCX: 0000000000000000 [ 1160.277263] RDX: 0000000000000001 RSI: ffffffff985995a1 RDI: 00000000ffffffff [ 1160.279571] RBP: ffffdc9c45a80000 R08: 0000000000000000 R09: 00000000ffffdfff [ 1160.281794] R10: ffffaa2c4d59fb08 R11: ffffffff98940d08 R12: ffffdc9c45a80000 [ 1160.283920] R13: ffffffff985b6f94 R14: 0000000000000000 R15: ffffdc9c45a80000 [ 1160.286641] FS: 00007eff54ce1740(0000) GS:ffff99c67bd00000(0000) knlGS:0000000000000000 [ 1160.289498] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1160.291106] CR2: 00005628381a5f68 CR3: 0000000104712003 CR4: 0000000000170ee0 [ 1160.293031] Call Trace: [ 1160.293724] <TASK> [ 1160.294334] get_hwpoison_page+0x47d/0x570 [ 1160.295474] memory_failure+0x106/0xaa0 [ 1160.296474] ? security_capable+0x36/0x50 [ 1160.297524] hard_offline_page_store+0x43/0x80 [ 1160.298684] kernfs_fop_write_iter+0x11c/0x1b0 [ 1160.299829] new_sync_write+0xf9/0x160 [ 1160.300810] vfs_write+0x209/0x290 [ 1160.301835] ksys_write+0x4f/0xc0 [ 1160.302718] do_syscall_64+0x3b/0x90 [ 1160.303664] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 1160.304981] RIP: 0033:0x7eff54b018b7 As shown in the RIP address, this VM_BUG_ON in folio_entire_mapcount() is called from dump_page("hwpoison: unhandlable page") in get_any_page(). The below explains the mechanism of the race: CPU 0 CPU 1 memory_failure get_hwpoison_page get_any_page dump_page compound = PageCompound free_pages_prepare page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP folio_entire_mapcount VM_BUG_ON_FOLIO(!folio_test_large(folio)) So replace dump_page() with safer one, pr_err(). Link: https://lkml.kernel.org/r/20220427053220.719866-1-naoya.horiguchi@linux.dev Fixes: 74e8ee4 ("mm: Turn head_compound_mapcount() into folio_entire_mapcount()") Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: William Kucharski <william.kucharski@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Do not allow to write timestamps on RX rings if PF is being configured. When PF is being configured RX rings can be freed or rebuilt. If at the same time timestamps are updated, the kernel will crash by dereferencing null RX ring pointer. PID: 1449 TASK: ff187d28ed658040 CPU: 34 COMMAND: "ice-ptp-0000:51" #0 [ff1966a94a713bb0] machine_kexec at ffffffff9d05a0be #1 [ff1966a94a713c08] __crash_kexec at ffffffff9d192e9d #2 [ff1966a94a713cd0] crash_kexec at ffffffff9d1941bd #3 [ff1966a94a713ce8] oops_end at ffffffff9d01bd54 #4 [ff1966a94a713d08] no_context at ffffffff9d06bda4 #5 [ff1966a94a713d60] __bad_area_nosemaphore at ffffffff9d06c10c torvalds#6 [ff1966a94a713da8] do_page_fault at ffffffff9d06cae4 torvalds#7 [ff1966a94a713de0] page_fault at ffffffff9da0107e [exception RIP: ice_ptp_update_cached_phctime+91] RIP: ffffffffc076db8b RSP: ff1966a94a713e98 RFLAGS: 00010246 RAX: 16e3db9c6b7ccae4 RBX: ff187d269dd3c180 RCX: ff187d269cd4d018 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ff187d269cfcc644 R8: ff187d339b9641b0 R9: 0000000000000000 R10: 0000000000000002 R11: 0000000000000000 R12: ff187d269cfcc648 R13: ffffffff9f128784 R14: ffffffff9d101b70 R15: ff187d269cfcc640 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 torvalds#8 [ff1966a94a713ea0] ice_ptp_periodic_work at ffffffffc076dbef [ice] torvalds#9 [ff1966a94a713ee0] kthread_worker_fn at ffffffff9d101c1b torvalds#10 [ff1966a94a713f10] kthread at ffffffff9d101b4d torvalds#11 [ff1966a94a713f50] ret_from_fork at ffffffff9da0023f Fixes: 77a7811 ("ice: enable receive hardware timestamping") Signed-off-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com> Reviewed-by: Michal Schmidt <mschmidt@redhat.com> Tested-by: Dave Cain <dcain@redhat.com> Tested-by: Gurucharan <gurucharanx.g@intel.com> (A Contingent worker at Intel) Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
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Will reported the following splat when running with Protected KVM enabled: [ 2.427181] ------------[ cut here ]------------ [ 2.427668] WARNING: CPU: 3 PID: 1 at arch/arm64/kvm/mmu.c:489 __create_hyp_private_mapping+0x118/0x1ac [ 2.428424] Modules linked in: [ 2.429040] CPU: 3 PID: 1 Comm: swapper/0 Not tainted 5.18.0-rc2-00084-g8635adc4efc7 #1 [ 2.429589] Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015 [ 2.430286] pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 2.430734] pc : __create_hyp_private_mapping+0x118/0x1ac [ 2.431091] lr : create_hyp_exec_mappings+0x40/0x80 [ 2.431377] sp : ffff80000803baf0 [ 2.431597] x29: ffff80000803bb00 x28: 0000000000000000 x27: 0000000000000000 [ 2.432156] x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000000 [ 2.432561] x23: ffffcd96c343b000 x22: 0000000000000000 x21: ffff80000803bb40 [ 2.433004] x20: 0000000000000004 x19: 0000000000001800 x18: 0000000000000000 [ 2.433343] x17: 0003e68cf7efdd70 x16: 0000000000000004 x15: fffffc81f602a2c8 [ 2.434053] x14: ffffdf8380000000 x13: ffffcd9573200000 x12: ffffcd96c343b000 [ 2.434401] x11: 0000000000000004 x10: ffffcd96c1738000 x9 : 0000000000000004 [ 2.434812] x8 : ffff80000803bb40 x7 : 7f7f7f7f7f7f7f7f x6 : 544f422effff306b [ 2.435136] x5 : 000000008020001e x4 : ffff207d80a88c00 x3 : 0000000000000005 [ 2.435480] x2 : 0000000000001800 x1 : 000000014f4ab800 x0 : 000000000badca11 [ 2.436149] Call trace: [ 2.436600] __create_hyp_private_mapping+0x118/0x1ac [ 2.437576] create_hyp_exec_mappings+0x40/0x80 [ 2.438180] kvm_init_vector_slots+0x180/0x194 [ 2.458941] kvm_arch_init+0x80/0x274 [ 2.459220] kvm_init+0x48/0x354 [ 2.459416] arm_init+0x20/0x2c [ 2.459601] do_one_initcall+0xbc/0x238 [ 2.459809] do_initcall_level+0x94/0xb4 [ 2.460043] do_initcalls+0x54/0x94 [ 2.460228] do_basic_setup+0x1c/0x28 [ 2.460407] kernel_init_freeable+0x110/0x178 [ 2.460610] kernel_init+0x20/0x1a0 [ 2.460817] ret_from_fork+0x10/0x20 [ 2.461274] ---[ end trace 0000000000000000 ]--- Indeed, the Protected KVM mode promotes __create_hyp_private_mapping() to a hypercall as EL1 no longer has access to the hypervisor's stage-1 page-table. However, the call from kvm_init_vector_slots() happens after pKVM has been initialized on the primary CPU, but before it has been initialized on secondaries. As such, if the KVM initcall procedure is migrated from one CPU to another in this window, the hypercall may end up running on a CPU for which EL2 has not been initialized. Fortunately, the pKVM hypervisor doesn't rely on the host to re-map the vectors in the private range, so the hypercall in question is in fact superfluous. Skip it when pKVM is enabled. Reported-by: Will Deacon <will@kernel.org> Signed-off-by: Quentin Perret <qperret@google.com> [maz: simplified the checks slightly] Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220513092607.35233-1-qperret@google.com
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The splat below can be seen when running kvm-unit-test:
=============================
WARNING: suspicious RCU usage
5.18.0-rc7 #5 Tainted: G IOE
-----------------------------
/home/kernel/linux/arch/x86/kvm/../../../virt/kvm/eventfd.c:80 RCU-list traversed in non-reader section!!
other info that might help us debug this:
rcu_scheduler_active = 2, debug_locks = 1
4 locks held by qemu-system-x86/35124:
#0: ffff9725391d80b8 (&vcpu->mutex){+.+.}-{4:4}, at: kvm_vcpu_ioctl+0x77/0x710 [kvm]
#1: ffffbd25cfb2a0b8 (&kvm->srcu){....}-{0:0}, at: vcpu_enter_guest+0xdeb/0x1900 [kvm]
#2: ffffbd25cfb2b920 (&kvm->irq_srcu){....}-{0:0}, at: kvm_hv_notify_acked_sint+0x79/0x1e0 [kvm]
#3: ffffbd25cfb2b920 (&kvm->irq_srcu){....}-{0:0}, at: irqfd_resampler_ack+0x5/0x110 [kvm]
stack backtrace:
CPU: 2 PID: 35124 Comm: qemu-system-x86 Tainted: G IOE 5.18.0-rc7 #5
Call Trace:
<TASK>
dump_stack_lvl+0x6c/0x9b
irqfd_resampler_ack+0xfd/0x110 [kvm]
kvm_notify_acked_gsi+0x32/0x90 [kvm]
kvm_hv_notify_acked_sint+0xc5/0x1e0 [kvm]
kvm_hv_set_msr_common+0xec1/0x1160 [kvm]
kvm_set_msr_common+0x7c3/0xf60 [kvm]
vmx_set_msr+0x394/0x1240 [kvm_intel]
kvm_set_msr_ignored_check+0x86/0x200 [kvm]
kvm_emulate_wrmsr+0x4f/0x1f0 [kvm]
vmx_handle_exit+0x6fb/0x7e0 [kvm_intel]
vcpu_enter_guest+0xe5a/0x1900 [kvm]
kvm_arch_vcpu_ioctl_run+0x16e/0xac0 [kvm]
kvm_vcpu_ioctl+0x279/0x710 [kvm]
__x64_sys_ioctl+0x83/0xb0
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
resampler-list is protected by irq_srcu (see kvm_irqfd_assign), so fix
the false positive by using list_for_each_entry_srcu().
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Message-Id: <1652950153-12489-1-git-send-email-wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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The rcutorture module is used to run torture tests that validate RCU. rcutorture takes a variety of module parameters that configure the functionality of the test. Amongst these parameters are the types of synchronization mechanisms that the rcu_torture_writer and rcu_torture_fakewriter tasks may use, and the torture_type of the run which determines what read and sync operations are used by the various writer and reader tasks that run throughout the test. When the module is configured to only use sync types for which the specified torture_type does not implement the necessary operations, we can end up in a state where nsynctypes is 0. This is not an erroneous state, but it currently crashes the kernel with a #DE due to nsynctypes being used with a modulo operator in rcu_torture_fakewriter(). Here is an example of such a #DE: $ insmod ./rcutorture.ko gp_cond=1 gp_cond_exp=0 gp_exp=0 gp_poll_exp=0 gp_normal=0 gp_poll=0 gp_poll_exp=0 verbose=9999 torture_type=trivial ... [ 8536.525096] divide error: 0000 [#1] PREEMPT SMP PTI [ 8536.525101] CPU: 30 PID: 392138 Comm: rcu_torture_fak Kdump: loaded Tainted: G S 5.17.0-rc1-00179-gc8c42c80febd torvalds#24 [ 8536.525105] Hardware name: Quanta Twin Lakes MP/Twin Lakes Passive MP, BIOS F09_3A23 12/08/2020 [ 8536.525106] RIP: 0010:rcu_torture_fakewriter+0xf1/0x2d0 [rcutorture] [ 8536.525121] Code: 00 31 d2 8d 0c f5 00 00 00 00 48 63 c9 48 f7 f1 48 85 d2 0f 84 79 ff ff ff 48 89 e7 e8 78 78 01 00 48 63 0d 29 ca 00 00 31 d2 <48> f7 f1 8b 04 95 00 05 4e a0 83 f8 06 0f 84 ad 00 00 00 7f 1f 83 [ 8536.525124] RSP: 0018:ffffc9000777fef0 EFLAGS: 00010246 [ 8536.525127] RAX: 00000000223d006e RBX: cccccccccccccccd RCX: 0000000000000000 [ 8536.525130] RDX: 0000000000000000 RSI: ffffffff824315b9 RDI: ffffc9000777fef0 [ 8536.525132] RBP: ffffc9000487bb30 R08: 0000000000000002 R09: 000000000002a580 [ 8536.525134] R10: ffffffff82c5f920 R11: 0000000000000000 R12: ffff8881a2c35d00 [ 8536.525136] R13: ffff8881540c8d00 R14: ffffffffa04d39d0 R15: 0000000000000000 [ 8536.525137] FS: 0000000000000000(0000) GS:ffff88903ff80000(0000) knlGS:0000000000000000 [ 8536.525140] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 8536.525142] CR2: 00007f839f022000 CR3: 0000000002c0a006 CR4: 00000000007706e0 [ 8536.525144] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 8536.525145] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 8536.525147] PKRU: 55555554 [ 8536.525148] Call Trace: [ 8536.525150] <TASK> [ 8536.525153] kthread+0xe8/0x110 [ 8536.525161] ? kthread_complete_and_exit+0x20/0x20 [ 8536.525167] ret_from_fork+0x22/0x30 [ 8536.525174] </TASK> The solution is to gracefully handle the case of nsynctypes being 0 in rcu_torture_fakewriter() by not performing any work. This is already being done in rcu_torture_writer(), though there is a missing return on that path which will be fixed in a subsequent patch. Signed-off-by: David Vernet <void@manifault.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
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It can happen that the parent of a bfqq changes between the moment we decide two queues are worth to merge (and set bic->stable_merge_bfqq) and the moment bfq_setup_merge() is called. This can happen e.g. because the process submitted IO for a different cgroup and thus bfqq got reparented. It can even happen that the bfqq we are merging with has parent cgroup that is already offline and going to be destroyed in which case the merge can lead to use-after-free issues such as: BUG: KASAN: use-after-free in __bfq_deactivate_entity+0x9cb/0xa50 Read of size 8 at addr ffff88800693c0c0 by task runc:[2:INIT]/10544 CPU: 0 PID: 10544 Comm: runc:[2:INIT] Tainted: G E 5.15.2-0.g5fb85fd-default #1 openSUSE Tumbleweed (unreleased) f1f3b891c72369aebecd2e43e4641a6358867c70 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a-rebuilt.opensuse.org 04/01/2014 Call Trace: <IRQ> dump_stack_lvl+0x46/0x5a print_address_description.constprop.0+0x1f/0x140 ? __bfq_deactivate_entity+0x9cb/0xa50 kasan_report.cold+0x7f/0x11b ? __bfq_deactivate_entity+0x9cb/0xa50 __bfq_deactivate_entity+0x9cb/0xa50 ? update_curr+0x32f/0x5d0 bfq_deactivate_entity+0xa0/0x1d0 bfq_del_bfqq_busy+0x28a/0x420 ? resched_curr+0x116/0x1d0 ? bfq_requeue_bfqq+0x70/0x70 ? check_preempt_wakeup+0x52b/0xbc0 __bfq_bfqq_expire+0x1a2/0x270 bfq_bfqq_expire+0xd16/0x2160 ? try_to_wake_up+0x4ee/0x1260 ? bfq_end_wr_async_queues+0xe0/0xe0 ? _raw_write_unlock_bh+0x60/0x60 ? _raw_spin_lock_irq+0x81/0xe0 bfq_idle_slice_timer+0x109/0x280 ? bfq_dispatch_request+0x4870/0x4870 __hrtimer_run_queues+0x37d/0x700 ? enqueue_hrtimer+0x1b0/0x1b0 ? kvm_clock_get_cycles+0xd/0x10 ? ktime_get_update_offsets_now+0x6f/0x280 hrtimer_interrupt+0x2c8/0x740 Fix the problem by checking that the parent of the two bfqqs we are merging in bfq_setup_merge() is the same. Link: https://lore.kernel.org/linux-block/20211125172809.GC19572@quack2.suse.cz/ CC: stable@vger.kernel.org Fixes: 430a67f ("block, bfq: merge bursts of newly-created queues") Tested-by: "yukuai (C)" <yukuai3@huawei.com> Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20220401102752.8599-2-jack@suse.cz Signed-off-by: Jens Axboe <axboe@kernel.dk>
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If bitmap area contains invalid data, kernel will crash then mdadm triggers "Segmentation fault". This is cluster-md speical bug. In non-clustered env, mdadm will handle broken metadata case. In clustered array, only kernel space handles bitmap slot info. But even this bug only happened in clustered env, current sanity check is wrong, the code should be changed. How to trigger: (faulty injection) dd if=/dev/zero bs=1M count=1 oflag=direct of=/dev/sda dd if=/dev/zero bs=1M count=1 oflag=direct of=/dev/sdb mdadm -C /dev/md0 -b clustered -e 1.2 -n 2 -l mirror /dev/sda /dev/sdb mdadm -Ss echo aaa > magic.txt == below modifying slot 2 bitmap data == dd if=magic.txt of=/dev/sda seek=16384 bs=1 count=3 <== destroy magic dd if=/dev/zero of=/dev/sda seek=16436 bs=1 count=4 <== ZERO chunksize mdadm -A /dev/md0 /dev/sda /dev/sdb == kernel crashes. mdadm outputs "Segmentation fault" == Reason of kernel crash: In md_bitmap_read_sb (called by md_bitmap_create), bad bitmap magic didn't block chunksize assignment, and zero value made DIV_ROUND_UP_SECTOR_T() trigger "divide error". Crash log: kernel: md: md0 stopped. kernel: md/raid1:md0: not clean -- starting background reconstruction kernel: md/raid1:md0: active with 2 out of 2 mirrors kernel: dlm: ... ... kernel: md-cluster: Joined cluster 44810aba-38bb-e6b8-daca-bc97a0b254aa slot 1 kernel: md0: invalid bitmap file superblock: bad magic kernel: md_bitmap_copy_from_slot can't get bitmap from slot 2 kernel: md-cluster: Could not gather bitmaps from slot 2 kernel: divide error: 0000 [#1] SMP NOPTI kernel: CPU: 0 PID: 1603 Comm: mdadm Not tainted 5.14.6-1-default kernel: Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) kernel: RIP: 0010:md_bitmap_create+0x1d1/0x850 [md_mod] kernel: RSP: 0018:ffffc22ac0843ba0 EFLAGS: 00010246 kernel: ... ... kernel: Call Trace: kernel: ? dlm_lock_sync+0xd0/0xd0 [md_cluster 77fe..7a0] kernel: md_bitmap_copy_from_slot+0x2c/0x290 [md_mod 24ea..d3a] kernel: load_bitmaps+0xec/0x210 [md_cluster 77fe..7a0] kernel: md_bitmap_load+0x81/0x1e0 [md_mod 24ea..d3a] kernel: do_md_run+0x30/0x100 [md_mod 24ea..d3a] kernel: md_ioctl+0x1290/0x15a0 [md_mod 24ea....d3a] kernel: ? mddev_unlock+0xaa/0x130 [md_mod 24ea..d3a] kernel: ? blkdev_ioctl+0xb1/0x2b0 kernel: block_ioctl+0x3b/0x40 kernel: __x64_sys_ioctl+0x7f/0xb0 kernel: do_syscall_64+0x59/0x80 kernel: ? exit_to_user_mode_prepare+0x1ab/0x230 kernel: ? syscall_exit_to_user_mode+0x18/0x40 kernel: ? do_syscall_64+0x69/0x80 kernel: entry_SYSCALL_64_after_hwframe+0x44/0xae kernel: RIP: 0033:0x7f4a15fa722b kernel: ... ... kernel: ---[ end trace 8afa7612f559c868 ]--- kernel: RIP: 0010:md_bitmap_create+0x1d1/0x850 [md_mod] Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Guoqing Jiang <guoqing.jiang@linux.dev> Signed-off-by: Heming Zhao <heming.zhao@suse.com> Signed-off-by: Song Liu <song@kernel.org>
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On our ZynqMP system we observe, that a NVMe drive that resets itself while doing a firmware update causes a Kernel crash like this: [ 67.720772] pcieport 0000:02:02.0: pciehp: Slot(2): Link Down [ 67.720783] pcieport 0000:02:02.0: pciehp: Slot(2): Card not present [ 67.720795] nvme 0000:04:00.0: PME# disabled [ 67.720849] Internal error: synchronous external abort: 96000010 [#1] PREEMPT SMP [ 67.720853] nwl-pcie fd0e0000.pcie: Slave error Analysis: When nvme_dev_disable() is called because of this PCIe hotplug event, pci_is_enabled() is still true. And accessing the NVMe drive which is currently not available as it's in reboot process causes this "synchronous external abort" on this ARM64 platform. This patch adds the pci_device_is_present() check as well, which returns false in this "Card not present" hot-plug case. With this change, the NVMe driver does not try to access the NVMe registers any more and the FW update finishes without any problems. Signed-off-by: Stefan Roese <sr@denx.de> Signed-off-by: Christoph Hellwig <hch@lst.de>
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Use hypercall to emulate MSR read/write for the TDX platform. There are two viable approaches for doing MSRs in a TD guest: 1. Execute the RDMSR/WRMSR instructions like most VMs and bare metal do. Some will succeed, others will cause a #VE. All of those that cause a #VE will be handled with a TDCALL. 2. Use paravirt infrastructure. The paravirt hook has to keep a list of which MSRs would cause a #VE and use a TDCALL. All other MSRs execute RDMSR/WRMSR instructions directly. The second option can be ruled out because the list of MSRs was challenging to maintain. That leaves option #1 as the only viable solution for the minimal TDX support. Kernel relies on the exception fixup machinery to handle MSR access errors. #VE handler uses the same exception fixup code as #GP. It covers MSR accesses along with other types of fixups. For performance-critical MSR writes (like TSC_DEADLINE), future patches will replace the WRMSR/#VE sequence with the direct TDCALL. RDMSR and WRMSR specification details can be found in Guest-Host-Communication Interface (GHCI) for Intel Trust Domain Extensions (Intel TDX) specification, sec titled "TDG.VP. VMCALL<Instruction.RDMSR>" and "TDG.VP.VMCALL<Instruction.WRMSR>". Co-developed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Andi Kleen <ak@linux.intel.com> Reviewed-by: Tony Luck <tony.luck@intel.com> Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20220405232939.73860-10-kirill.shutemov@linux.intel.com
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A panic was reported in the init process on AMD: Run /sbin/init as init process init[1]: segfault at f7fd5ca0 ip 00000000f7f5bbc7 sp 00000000ffa06aa0 error 7 in libc.so[f7f51000+4e000] Code: 8a 44 24 10 88 41 ff 8b 44 24 10 83 c4 2c 5b 5e 5f 5d c3 53 83 ec 08 8b 5c 24 10 81 fb 00 f0 ff ff 76 0c e8 ba dc ff ff f7 db <89> 18 83 cb ff 83 c4 08 89 d8 5b c3 e8 81 60 ff ff 05 28 84 07 00 Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b CPU: 1 PID: 1 Comm: init Tainted: G W 5.18.0-rc7-next-20220519 #1 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.15.0-0-g2dd4b9b3f840-prebuilt.qemu.org 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x57/0x7d panic+0x10f/0x28d do_exit.cold+0x18/0x48 do_group_exit+0x2e/0xb0 get_signal+0xb6d/0xb80 arch_do_signal_or_restart+0x31/0x760 ? show_opcodes.cold+0x1c/0x21 ? force_sig_fault+0x49/0x70 exit_to_user_mode_prepare+0x131/0x1a0 irqentry_exit_to_user_mode+0x5/0x30 asm_exc_page_fault+0x27/0x30 RIP: 0023:0xf7f5bbc7 Code: 8a 44 24 10 88 41 ff 8b 44 24 10 83 c4 2c 5b 5e 5f 5d c3 53 83 ec 08 8b 5c 24 10 81 fb 00 f0 ff ff 76 0c e8 ba dc ff ff f7 db <89> 18 83 cb ff 83 c4 08 89 d8 5b c3 e8 81 60 ff ff 05 28 84 07 00 RSP: 002b:00000000ffa06aa0 EFLAGS: 00000217 RAX: 00000000f7fd5ca0 RBX: 000000000000000c RCX: 0000000000001000 RDX: 0000000000000001 RSI: 00000000f7fd5b60 RDI: 00000000f7fd5b60 RBP: 00000000f7fd1c1c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 </TASK> The task's CX register got corrupted by commit 8c42819 ("x86/entry: Use PUSH_AND_CLEAR_REGS for compat"), which overlooked the fact that compat SYSCALL apparently stores the user's CX value in BP. Before that commit, CX was saved from its stashed value in BP: pushq %rbp /* pt_regs->cx (stashed in bp) */ But then it got changed to: pushq %rcx /* pt_regs->cx */ So the wrong value got saved and later restored back to the user. Fix it by pushing the correct value again (BP) for regs->cx. Fixes: 8c42819 ("x86/entry: Use PUSH_AND_CLEAR_REGS for compat") Reported-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Guenter Roeck <linux@roeck-us.net> Link: https://lkml.kernel.org/r/b5a26592c9dd60bbacdf97974a7433fd802a5593.1652985970.git.jpoimboe@kernel.org
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Commit 467f432 ("RDMA/core: Split port and device counter sysfs attributes") accidentally almost exposed hw counters to non-init net namespaces. It didn't expose them fully, as an attempt to read any of those counters leads to a crash like this one: [42021.807566] BUG: kernel NULL pointer dereference, address: 0000000000000028 [42021.814463] #PF: supervisor read access in kernel mode [42021.819549] #PF: error_code(0x0000) - not-present page [42021.824636] PGD 0 P4D 0 [42021.827145] Oops: 0000 [#1] SMP PTI [42021.830598] CPU: 82 PID: 2843922 Comm: switchto-defaul Kdump: loaded Tainted: G S W I XXX [42021.841697] Hardware name: XXX [42021.849619] RIP: 0010:hw_stat_device_show+0x1e/0x40 [ib_core] [42021.855362] Code: 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 0f 1f 44 00 00 49 89 d0 4c 8b 5e 20 48 8b 8f b8 04 00 00 48 81 c7 f0 fa ff ff <48> 8b 41 28 48 29 ce 48 83 c6 d0 48 c1 ee 04 69 d6 ab aa aa aa 48 [42021.873931] RSP: 0018:ffff97fe90f03da0 EFLAGS: 00010287 [42021.879108] RAX: ffff9406988a8c60 RBX: ffff940e1072d438 RCX: 0000000000000000 [42021.886169] RDX: ffff94085f1aa000 RSI: ffff93c6cbbdbcb0 RDI: ffff940c7517aef0 [42021.893230] RBP: ffff97fe90f03e70 R08: ffff94085f1aa000 R09: 0000000000000000 [42021.900294] R10: ffff94085f1aa000 R11: ffffffffc0775680 R12: ffffffff87ca2530 [42021.907355] R13: ffff940651602840 R14: ffff93c6cbbdbcb0 R15: ffff94085f1aa000 [42021.914418] FS: 00007fda1a3b9700(0000) GS:ffff94453fb80000(0000) knlGS:0000000000000000 [42021.922423] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [42021.928130] CR2: 0000000000000028 CR3: 00000042dcfb8003 CR4: 00000000003726f0 [42021.935194] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [42021.942257] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [42021.949324] Call Trace: [42021.951756] <TASK> [42021.953842] [<ffffffff86c58674>] ? show_regs+0x64/0x70 [42021.959030] [<ffffffff86c58468>] ? __die+0x78/0xc0 [42021.963874] [<ffffffff86c9ef75>] ? page_fault_oops+0x2b5/0x3b0 [42021.969749] [<ffffffff87674b92>] ? exc_page_fault+0x1a2/0x3c0 [42021.975549] [<ffffffff87801326>] ? asm_exc_page_fault+0x26/0x30 [42021.981517] [<ffffffffc0775680>] ? __pfx_show_hw_stats+0x10/0x10 [ib_core] [42021.988482] [<ffffffffc077564e>] ? hw_stat_device_show+0x1e/0x40 [ib_core] [42021.995438] [<ffffffff86ac7f8e>] dev_attr_show+0x1e/0x50 [42022.000803] [<ffffffff86a3eeb1>] sysfs_kf_seq_show+0x81/0xe0 [42022.006508] [<ffffffff86a11134>] seq_read_iter+0xf4/0x410 [42022.011954] [<ffffffff869f4b2e>] vfs_read+0x16e/0x2f0 [42022.017058] [<ffffffff869f50ee>] ksys_read+0x6e/0xe0 [42022.022073] [<ffffffff8766f1ca>] do_syscall_64+0x6a/0xa0 [42022.027441] [<ffffffff8780013b>] entry_SYSCALL_64_after_hwframe+0x78/0xe2 The problem can be reproduced using the following steps: ip netns add foo ip netns exec foo bash cat /sys/class/infiniband/mlx4_0/hw_counters/* The panic occurs because of casting the device pointer into an ib_device pointer using container_of() in hw_stat_device_show() is wrong and leads to a memory corruption. However the real problem is that hw counters should never been exposed outside of the non-init net namespace. Fix this by saving the index of the corresponding attribute group (it might be 1 or 2 depending on the presence of driver-specific attributes) and zeroing the pointer to hw_counters group for compat devices during the initialization. With this fix applied hw_counters are not available in a non-init net namespace: find /sys/class/infiniband/mlx4_0/ -name hw_counters /sys/class/infiniband/mlx4_0/ports/1/hw_counters /sys/class/infiniband/mlx4_0/ports/2/hw_counters /sys/class/infiniband/mlx4_0/hw_counters ip netns add foo ip netns exec foo bash find /sys/class/infiniband/mlx4_0/ -name hw_counters Fixes: 467f432 ("RDMA/core: Split port and device counter sysfs attributes") Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Leon Romanovsky <leon@kernel.org> Cc: Maher Sanalla <msanalla@nvidia.com> Cc: linux-rdma@vger.kernel.org Cc: linux-kernel@vger.kernel.org Link: https://patch.msgid.link/20250227165420.3430301-1-roman.gushchin@linux.dev Reviewed-by: Parav Pandit <parav@nvidia.com> Signed-off-by: Leon Romanovsky <leon@kernel.org>
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When cur_qp isn't NULL, in order to avoid fetching the QP from the radix tree again we check if the next cqe QP is identical to the one we already have. The bug however is that we are checking if the QP is identical by checking the QP number inside the CQE against the QP number inside the mlx5_ib_qp, but that's wrong since the QP number from the CQE is from FW so it should be matched against mlx5_core_qp which is our FW QP number. Otherwise we could use the wrong QP when handling a CQE which could cause the kernel trace below. This issue is mainly noticeable over QPs 0 & 1, since for now they are the only QPs in our driver whereas the QP number inside mlx5_ib_qp doesn't match the QP number inside mlx5_core_qp. BUG: kernel NULL pointer dereference, address: 0000000000000012 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: Oops: 0000 [#1] SMP CPU: 0 UID: 0 PID: 7927 Comm: kworker/u62:1 Not tainted 6.14.0-rc3+ torvalds#189 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014 Workqueue: ib-comp-unb-wq ib_cq_poll_work [ib_core] RIP: 0010:mlx5_ib_poll_cq+0x4c7/0xd90 [mlx5_ib] Code: 03 00 00 8d 58 ff 21 cb 66 39 d3 74 39 48 c7 c7 3c 89 6e a0 0f b7 db e8 b7 d2 b3 e0 49 8b 86 60 03 00 00 48 c7 c7 4a 89 6e a0 <0f> b7 5c 98 02 e8 9f d2 b3 e0 41 0f b7 86 78 03 00 00 83 e8 01 21 RSP: 0018:ffff88810511bd60 EFLAGS: 00010046 RAX: 0000000000000010 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffff88885fa1b3c0 RDI: ffffffffa06e894a RBP: 00000000000000b0 R08: 0000000000000000 R09: ffff88810511bc10 R10: 0000000000000001 R11: 0000000000000001 R12: ffff88810d593000 R13: ffff88810e579108 R14: ffff888105146000 R15: 00000000000000b0 FS: 0000000000000000(0000) GS:ffff88885fa00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000012 CR3: 00000001077e6001 CR4: 0000000000370eb0 Call Trace: <TASK> ? __die+0x20/0x60 ? page_fault_oops+0x150/0x3e0 ? exc_page_fault+0x74/0x130 ? asm_exc_page_fault+0x22/0x30 ? mlx5_ib_poll_cq+0x4c7/0xd90 [mlx5_ib] __ib_process_cq+0x5a/0x150 [ib_core] ib_cq_poll_work+0x31/0x90 [ib_core] process_one_work+0x169/0x320 worker_thread+0x288/0x3a0 ? work_busy+0xb0/0xb0 kthread+0xd7/0x1f0 ? kthreads_online_cpu+0x130/0x130 ? kthreads_online_cpu+0x130/0x130 ret_from_fork+0x2d/0x50 ? kthreads_online_cpu+0x130/0x130 ret_from_fork_asm+0x11/0x20 </TASK> Fixes: e126ba9 ("mlx5: Add driver for Mellanox Connect-IB adapters") Signed-off-by: Patrisious Haddad <phaddad@nvidia.com> Reviewed-by: Edward Srouji <edwards@nvidia.com> Link: https://patch.msgid.link/4ada09d41f1e36db62c44a9b25c209ea5f054316.1741875692.git.leon@kernel.org Signed-off-by: Leon Romanovsky <leon@kernel.org>
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There is case as below could trigger kernel dump: Use U-Boot to start remote processor(rproc) with resource table published to a fixed address by rproc. After Kernel boots up, stop the rproc, load a new firmware which doesn't have resource table ,and start rproc. When starting rproc with a firmware not have resource table, `memcpy(loaded_table, rproc->cached_table, rproc->table_sz)` will trigger dump, because rproc->cache_table is set to NULL during the last stop operation, but rproc->table_sz is still valid. This issue is found on i.MX8MP and i.MX9. Dump as below: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 Mem abort info: ESR = 0x0000000096000004 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x04: level 0 translation fault Data abort info: ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000 CM = 0, WnR = 0, TnD = 0, TagAccess = 0 GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 user pgtable: 4k pages, 48-bit VAs, pgdp=000000010af63000 [0000000000000000] pgd=0000000000000000, p4d=0000000000000000 Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP Modules linked in: CPU: 2 UID: 0 PID: 1060 Comm: sh Not tainted 6.14.0-rc7-next-20250317-dirty torvalds#38 Hardware name: NXP i.MX8MPlus EVK board (DT) pstate: a0000005 (NzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : __pi_memcpy_generic+0x110/0x22c lr : rproc_start+0x88/0x1e0 Call trace: __pi_memcpy_generic+0x110/0x22c (P) rproc_boot+0x198/0x57c state_store+0x40/0x104 dev_attr_store+0x18/0x2c sysfs_kf_write+0x7c/0x94 kernfs_fop_write_iter+0x120/0x1cc vfs_write+0x240/0x378 ksys_write+0x70/0x108 __arm64_sys_write+0x1c/0x28 invoke_syscall+0x48/0x10c el0_svc_common.constprop.0+0xc0/0xe0 do_el0_svc+0x1c/0x28 el0_svc+0x30/0xcc el0t_64_sync_handler+0x10c/0x138 el0t_64_sync+0x198/0x19c Clear rproc->table_sz to address the issue. Fixes: 9dc9507 ("remoteproc: Properly deal with the resource table when detaching") Signed-off-by: Peng Fan <peng.fan@nxp.com> Link: https://lore.kernel.org/r/20250319100106.3622619-1-peng.fan@oss.nxp.com Signed-off-by: Bjorn Andersson <andersson@kernel.org>
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Jiayuan Chen says: ==================== bpf: Fix array bounds error with may_goto and add selftest Syzbot caught an array out-of-bounds bug [1]. It turns out that when the BPF program runs through do_misc_fixups(), it allocates an extra 8 bytes on the call stack, which eventually causes stack_depth to exceed 512. I was able to reproduce this issue probabilistically by enabling CONFIG_UBSAN=y and disabling CONFIG_BPF_JIT_ALWAYS_ON with the selfttest I provide in second patch(although it doesn't happen every time - I didn't dig deeper into why UBSAN behaves this way). Furthermore, if I set /proc/sys/net/core/bpf_jit_enable to 0 to disable the jit, a panic occurs, and the reason is the same, that bpf_func is assigned an incorrect address. [---[ end trace ]--- [Oops: general protection fault, probably for non-canonical address 0x100f0e0e0d090808: 0000 [#1] PREEMPT SMP NOPTI [Tainted: [W]=WARN, [O]=OOT_MODULE [RIP: 0010:bpf_test_run+0x1d2/0x360 [RSP: 0018:ffffafc7955178a0 EFLAGS: 00010246 [RAX: 100f0e0e0d090808 RBX: ffff8e9fdb2c4100 RCX: 0000000000000018 [RDX: 00000000002b5b18 RSI: ffffafc780497048 RDI: ffff8ea04d601700 [RBP: ffffafc780497000 R08: ffffafc795517a0c R09: 0000000000000000 [R10: 0000000000000000 R11: fefefefefefefeff R12: ffff8ea04d601700 [R13: ffffafc795517928 R14: ffffafc795517928 R15: 0000000000000000 [CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [CR2: 00007f181c064648 CR3: 00000001aa2be003 CR4: 0000000000770ef0 [DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [DR3: 0000000000000000 DR6: 00000000fffe07f0 DR7: 0000000000000400 [PKRU: 55555554 [Call Trace: [ <TASK> [ ? die_addr+0x36/0x90 [ ? exc_general_protection+0x237/0x430 [ ? asm_exc_general_protection+0x26/0x30 [ ? bpf_test_run+0x1d2/0x360 [ ? bpf_test_run+0x10d/0x360 [ ? __link_object+0x12a/0x1e0 [ ? slab_build_skb+0x23/0x130 [ ? kmem_cache_alloc_noprof+0x2ea/0x3f0 [ ? sk_prot_alloc+0xc2/0x120 [ bpf_prog_test_run_skb+0x21b/0x590 [ __sys_bpf+0x340/0xa80 [ __x64_sys_bpf+0x1e/0x30 --- v2 -> v3: Optimized some code naming and conditional judgment logic. https://lore.kernel.org/bpf/20250213131214.164982-1-mrpre@163.com/T/ v1 -> v2: Directly reject loading programs with a stack size greater than 512 when jit disabled.(Suggested by Alexei Starovoitov) https://lore.kernel.org/bpf/20250212135251.85487-1-mrpre@163.com/T/ ==================== Link: https://patch.msgid.link/20250214091823.46042-1-mrpre@163.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Eduard Zingerman says: ==================== This patch set fixes a bug in copy_verifier_state() where the loop_entry field was not copied. This omission led to incorrect loop_entry fields remaining in env->cur_state, causing incorrect decisions about loop entry assignments in update_loop_entry(). An example of an unsafe program accepted by the verifier due to this bug can be found in patch #2. This bug can also cause an infinite loop in the verifier, see patch #5. Structure of the patch set: - Patch #1 fixes the bug but has a significant negative impact on verification performance for sched_ext programs. - Patch #3 mitigates the verification performance impact of patch #1 by avoiding clean_live_states() for states whose loop_entry is still being verified. This reduces the number of processed instructions for sched_ext programs by 28–92% in some cases. - Patches #5-6 simplify {get,update}_loop_entry() logic (and are not strictly necessary). - Patches torvalds#7–10 mitigate the memory overhead introduced by patch #1 when a program with iterator-based loop hits the 1M instruction limit. This is achieved by freeing states in env->free_list when their branches and used_as_loop_entry counts reach zero. Patches #1-4 were previously sent as a part of [1]. [1] https://lore.kernel.org/bpf/20250122120442.3536298-1-eddyz87@gmail.com/ ==================== Link: https://patch.msgid.link/20250215110411.3236773-1-eddyz87@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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…uctions
Add several ./test_progs tests:
- arena_atomics/load_acquire
- arena_atomics/store_release
- verifier_load_acquire/*
- verifier_store_release/*
- verifier_precision/bpf_load_acquire
- verifier_precision/bpf_store_release
The last two tests are added to check if backtrack_insn() handles the
new instructions correctly.
Additionally, the last test also makes sure that the verifier
"remembers" the value (in src_reg) we store-release into e.g. a stack
slot. For example, if we take a look at the test program:
#0: r1 = 8;
/* store_release((u64 *)(r10 - 8), r1); */
#1: .8byte %[store_release];
#2: r1 = *(u64 *)(r10 - 8);
#3: r2 = r10;
#4: r2 += r1;
#5: r0 = 0;
torvalds#6: exit;
At #1, if the verifier doesn't remember that we wrote 8 to the stack,
then later at #4 we would be adding an unbounded scalar value to the
stack pointer, which would cause the program to be rejected:
VERIFIER LOG:
=============
...
math between fp pointer and register with unbounded min value is not allowed
For easier CI integration, instead of using built-ins like
__atomic_{load,store}_n() which depend on the new
__BPF_FEATURE_LOAD_ACQ_STORE_REL pre-defined macro, manually craft
load-acquire/store-release instructions using __imm_insn(), as suggested
by Eduard.
All new tests depend on:
(1) Clang major version >= 18, and
(2) ENABLE_ATOMICS_TESTS is defined (currently implies -mcpu=v3 or
v4), and
(3) JIT supports load-acquire/store-release (currently arm64 and
x86-64)
In .../progs/arena_atomics.c:
/* 8-byte-aligned */
__u8 __arena_global load_acquire8_value = 0x12;
/* 1-byte hole */
__u16 __arena_global load_acquire16_value = 0x1234;
That 1-byte hole in the .addr_space.1 ELF section caused clang-17 to
crash:
fatal error: error in backend: unable to write nop sequence of 1 bytes
To work around such llvm-17 CI job failures, conditionally define
__arena_global variables as 64-bit if __clang_major__ < 18, to make sure
.addr_space.1 has no holes. Ideally we should avoid compiling this file
using clang-17 at all (arena tests depend on
__BPF_FEATURE_ADDR_SPACE_CAST, and are skipped for llvm-17 anyway), but
that is a separate topic.
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Peilin Ye <yepeilin@google.com>
Link: https://lore.kernel.org/r/1b46c6feaf0f1b6984d9ec80e500cc7383e9da1a.1741049567.git.yepeilin@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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perf test 11 hwmon fails on s390 with this error
# ./perf test -Fv 11
--- start ---
---- end ----
11.1: Basic parsing test : Ok
--- start ---
Testing 'temp_test_hwmon_event1'
Using CPUID IBM,3931,704,A01,3.7,002f
temp_test_hwmon_event1 -> hwmon_a_test_hwmon_pmu/temp_test_hwmon_event1/
FAILED tests/hwmon_pmu.c:189 Unexpected config for
'temp_test_hwmon_event1', 292470092988416 != 655361
---- end ----
11.2: Parsing without PMU name : FAILED!
--- start ---
Testing 'hwmon_a_test_hwmon_pmu/temp_test_hwmon_event1/'
FAILED tests/hwmon_pmu.c:189 Unexpected config for
'hwmon_a_test_hwmon_pmu/temp_test_hwmon_event1/',
292470092988416 != 655361
---- end ----
11.3: Parsing with PMU name : FAILED!
#
The root cause is in member test_event::config which is initialized
to 0xA0001 or 655361. During event parsing a long list event parsing
functions are called and end up with this gdb call stack:
#0 hwmon_pmu__config_term (hwm=0x168dfd0, attr=0x3ffffff5ee8,
term=0x168db60, err=0x3ffffff81c8) at util/hwmon_pmu.c:623
#1 hwmon_pmu__config_terms (pmu=0x168dfd0, attr=0x3ffffff5ee8,
terms=0x3ffffff5ea8, err=0x3ffffff81c8) at util/hwmon_pmu.c:662
#2 0x00000000012f870c in perf_pmu__config_terms (pmu=0x168dfd0,
attr=0x3ffffff5ee8, terms=0x3ffffff5ea8, zero=false,
apply_hardcoded=false, err=0x3ffffff81c8) at util/pmu.c:1519
#3 0x00000000012f88a4 in perf_pmu__config (pmu=0x168dfd0, attr=0x3ffffff5ee8,
head_terms=0x3ffffff5ea8, apply_hardcoded=false, err=0x3ffffff81c8)
at util/pmu.c:1545
#4 0x00000000012680c4 in parse_events_add_pmu (parse_state=0x3ffffff7fb8,
list=0x168dc00, pmu=0x168dfd0, const_parsed_terms=0x3ffffff6090,
auto_merge_stats=true, alternate_hw_config=10)
at util/parse-events.c:1508
#5 0x00000000012684c6 in parse_events_multi_pmu_add (parse_state=0x3ffffff7fb8,
event_name=0x168ec10 "temp_test_hwmon_event1", hw_config=10,
const_parsed_terms=0x0, listp=0x3ffffff6230, loc_=0x3ffffff70e0)
at util/parse-events.c:1592
torvalds#6 0x00000000012f0e4e in parse_events_parse (_parse_state=0x3ffffff7fb8,
scanner=0x16878c0) at util/parse-events.y:293
torvalds#7 0x00000000012695a0 in parse_events__scanner (str=0x3ffffff81d8
"temp_test_hwmon_event1", input=0x0, parse_state=0x3ffffff7fb8)
at util/parse-events.c:1867
torvalds#8 0x000000000126a1e8 in __parse_events (evlist=0x168b580,
str=0x3ffffff81d8 "temp_test_hwmon_event1", pmu_filter=0x0,
err=0x3ffffff81c8, fake_pmu=false, warn_if_reordered=true,
fake_tp=false) at util/parse-events.c:2136
torvalds#9 0x00000000011e36aa in parse_events (evlist=0x168b580,
str=0x3ffffff81d8 "temp_test_hwmon_event1", err=0x3ffffff81c8)
at /root/linux/tools/perf/util/parse-events.h:41
torvalds#10 0x00000000011e3e64 in do_test (i=0, with_pmu=false, with_alias=false)
at tests/hwmon_pmu.c:164
torvalds#11 0x00000000011e422c in test__hwmon_pmu (with_pmu=false)
at tests/hwmon_pmu.c:219
torvalds#12 0x00000000011e431c in test__hwmon_pmu_without_pmu (test=0x1610368
<suite.hwmon_pmu>, subtest=1) at tests/hwmon_pmu.c:23
where the attr::config is set to value 292470092988416 or 0x10a0000000000
in line 625 of file ./util/hwmon_pmu.c:
attr->config = key.type_and_num;
However member key::type_and_num is defined as union and bit field:
union hwmon_pmu_event_key {
long type_and_num;
struct {
int num :16;
enum hwmon_type type :8;
};
};
s390 is big endian and Intel is little endian architecture.
The events for the hwmon dummy pmu have num = 1 or num = 2 and
type is set to HWMON_TYPE_TEMP (which is 10).
On s390 this assignes member key::type_and_num the value of
0x10a0000000000 (which is 292470092988416) as shown in above
trace output.
Fix this and export the structure/union hwmon_pmu_event_key
so the test shares the same implementation as the event parsing
functions for union and bit fields. This should avoid
endianess issues on all platforms.
Output after:
# ./perf test -F 11
11.1: Basic parsing test : Ok
11.2: Parsing without PMU name : Ok
11.3: Parsing with PMU name : Ok
#
Fixes: 531ee0f ("perf test: Add hwmon "PMU" test")
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20250131112400.568975-1-tmricht@linux.ibm.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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Ian told me that there are many memory leaks in the hierarchy mode. I
can easily reproduce it with the follwing command.
$ make DEBUG=1 EXTRA_CFLAGS=-fsanitize=leak
$ perf record --latency -g -- ./perf test -w thloop
$ perf report -H --stdio
...
Indirect leak of 168 byte(s) in 21 object(s) allocated from:
#0 0x7f3414c16c65 in malloc ../../../../src/libsanitizer/lsan/lsan_interceptors.cpp:75
#1 0x55ed3602346e in map__get util/map.h:189
#2 0x55ed36024cc4 in hist_entry__init util/hist.c:476
#3 0x55ed36025208 in hist_entry__new util/hist.c:588
#4 0x55ed36027c05 in hierarchy_insert_entry util/hist.c:1587
#5 0x55ed36027e2e in hists__hierarchy_insert_entry util/hist.c:1638
torvalds#6 0x55ed36027fa4 in hists__collapse_insert_entry util/hist.c:1685
torvalds#7 0x55ed360283e8 in hists__collapse_resort util/hist.c:1776
torvalds#8 0x55ed35de0323 in report__collapse_hists /home/namhyung/project/linux/tools/perf/builtin-report.c:735
torvalds#9 0x55ed35de15b4 in __cmd_report /home/namhyung/project/linux/tools/perf/builtin-report.c:1119
torvalds#10 0x55ed35de43dc in cmd_report /home/namhyung/project/linux/tools/perf/builtin-report.c:1867
torvalds#11 0x55ed35e66767 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:351
torvalds#12 0x55ed35e66a0e in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:404
torvalds#13 0x55ed35e66b67 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:448
torvalds#14 0x55ed35e66eb0 in main /home/namhyung/project/linux/tools/perf/perf.c:556
torvalds#15 0x7f340ac33d67 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58
...
$ perf report -H --stdio 2>&1 | grep -c '^Indirect leak'
93
I found that hist_entry__delete() missed to release child entries in the
hierarchy tree (hroot_{in,out}). It needs to iterate the child entries
and call hist_entry__delete() recursively.
After this change:
$ perf report -H --stdio 2>&1 | grep -c '^Indirect leak'
0
Reported-by: Ian Rogers <irogers@google.com>
Tested-by Thomas Falcon <thomas.falcon@intel.com>
Reviewed-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20250307061250.320849-2-namhyung@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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The env.pmu_mapping can be leaked when it reads data from a pipe on AMD.
For a pipe data, it reads the header data including pmu_mapping from
PERF_RECORD_HEADER_FEATURE runtime. But it's already set in:
perf_session__new()
__perf_session__new()
evlist__init_trace_event_sample_raw()
evlist__has_amd_ibs()
perf_env__nr_pmu_mappings()
Then it'll overwrite that when it processes the HEADER_FEATURE record.
Here's a report from address sanitizer.
Direct leak of 2689 byte(s) in 1 object(s) allocated from:
#0 0x7fed8f814596 in realloc ../../../../src/libsanitizer/lsan/lsan_interceptors.cpp:98
#1 0x5595a7d416b1 in strbuf_grow util/strbuf.c:64
#2 0x5595a7d414ef in strbuf_init util/strbuf.c:25
#3 0x5595a7d0f4b7 in perf_env__read_pmu_mappings util/env.c:362
#4 0x5595a7d12ab7 in perf_env__nr_pmu_mappings util/env.c:517
#5 0x5595a7d89d2f in evlist__has_amd_ibs util/amd-sample-raw.c:315
torvalds#6 0x5595a7d87fb2 in evlist__init_trace_event_sample_raw util/sample-raw.c:23
torvalds#7 0x5595a7d7f893 in __perf_session__new util/session.c:179
torvalds#8 0x5595a7b79572 in perf_session__new util/session.h:115
torvalds#9 0x5595a7b7e9dc in cmd_report builtin-report.c:1603
torvalds#10 0x5595a7c019eb in run_builtin perf.c:351
torvalds#11 0x5595a7c01c92 in handle_internal_command perf.c:404
torvalds#12 0x5595a7c01deb in run_argv perf.c:448
torvalds#13 0x5595a7c02134 in main perf.c:556
torvalds#14 0x7fed85833d67 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58
Let's free the existing pmu_mapping data if any.
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Link: https://lore.kernel.org/r/20250311000416.817631-1-namhyung@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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The array contains only 5 elements, but the index calculated by veml6075_read_int_time_index can range from 0 to 7, which could lead to out-of-bounds access. The check prevents this issue. Coverity Issue CID 1574309: (#1 of 1): Out-of-bounds read (OVERRUN) overrun-local: Overrunning array veml6075_it_ms of 5 4-byte elements at element index 7 (byte offset 31) using index int_index (which evaluates to 7) This is hardening against potentially broken hardware. Good to have but not necessary to backport. Fixes: 3b82f43 ("iio: light: add VEML6075 UVA and UVB light sensor driver") Signed-off-by: Karan Sanghavi <karansanghvi98@gmail.com> Reviewed-by: Javier Carrasco <javier.carrasco.cruz@gmail.com> Link: https://patch.msgid.link/Z7dnrEpKQdRZ2qFU@Emma Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
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Patch series "mm: fixes for device-exclusive entries (hmm)", v2.
Discussing the PageTail() call in make_device_exclusive_range() with
Willy, I recently discovered [1] that device-exclusive handling does not
properly work with THP, making the hmm-tests selftests fail if THPs are
enabled on the system.
Looking into more details, I found that hugetlb is not properly fenced,
and I realized that something that was bugging me for longer -- how
device-exclusive entries interact with mapcounts -- completely breaks
migration/swapout/split/hwpoison handling of these folios while they have
device-exclusive PTEs.
The program below can be used to allocate 1 GiB worth of pages and making
them device-exclusive on a kernel with CONFIG_TEST_HMM.
Once they are device-exclusive, these folios cannot get swapped out
(proc$pid/smaps_rollup will always indicate 1 GiB RSS no matter how much
one forces memory reclaim), and when having a memory block onlined to
ZONE_MOVABLE, trying to offline it will loop forever and complain about
failed migration of a page that should be movable.
# echo offline > /sys/devices/system/memory/memory136/state
# echo online_movable > /sys/devices/system/memory/memory136/state
# ./hmm-swap &
... wait until everything is device-exclusive
# echo offline > /sys/devices/system/memory/memory136/state
[ 285.193431][T14882] page: refcount:2 mapcount:0 mapping:0000000000000000
index:0x7f20671f7 pfn:0x442b6a
[ 285.196618][T14882] memcg:ffff888179298000
[ 285.198085][T14882] anon flags: 0x5fff0000002091c(referenced|uptodate|
dirty|active|owner_2|swapbacked|node=1|zone=3|lastcpupid=0x7ff)
[ 285.201734][T14882] raw: ...
[ 285.204464][T14882] raw: ...
[ 285.207196][T14882] page dumped because: migration failure
[ 285.209072][T14882] page_owner tracks the page as allocated
[ 285.210915][T14882] page last allocated via order 0, migratetype
Movable, gfp_mask 0x140dca(GFP_HIGHUSER_MOVABLE|__GFP_COMP|__GFP_ZERO),
id 14926, tgid 14926 (hmm-swap), ts 254506295376, free_ts 227402023774
[ 285.216765][T14882] post_alloc_hook+0x197/0x1b0
[ 285.218874][T14882] get_page_from_freelist+0x76e/0x3280
[ 285.220864][T14882] __alloc_frozen_pages_noprof+0x38e/0x2740
[ 285.223302][T14882] alloc_pages_mpol+0x1fc/0x540
[ 285.225130][T14882] folio_alloc_mpol_noprof+0x36/0x340
[ 285.227222][T14882] vma_alloc_folio_noprof+0xee/0x1a0
[ 285.229074][T14882] __handle_mm_fault+0x2b38/0x56a0
[ 285.230822][T14882] handle_mm_fault+0x368/0x9f0
...
This series fixes all issues I found so far. There is no easy way to fix
without a bigger rework/cleanup. I have a bunch of cleanups on top (some
previous sent, some the result of the discussion in v1) that I will send
out separately once this landed and I get to it.
I wish we could just use some special present PROT_NONE PTEs instead of
these (non-present, non-none) fake-swap entries; but that just results in
the same problem we keep having (lack of spare PTE bits), and staring at
other similar fake-swap entries, that ship has sailed.
With this series, make_device_exclusive() doesn't actually belong into
mm/rmap.c anymore, but I'll leave moving that for another day.
I only tested this series with the hmm-tests selftests due to lack of HW,
so I'd appreciate some testing, especially if the interaction between two
GPUs wanting a device-exclusive entry works as expected.
<program>
#include <stdio.h>
#include <fcntl.h>
#include <stdint.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/ioctl.h>
#include <linux/types.h>
#include <linux/ioctl.h>
#define HMM_DMIRROR_EXCLUSIVE _IOWR('H', 0x05, struct hmm_dmirror_cmd)
struct hmm_dmirror_cmd {
__u64 addr;
__u64 ptr;
__u64 npages;
__u64 cpages;
__u64 faults;
};
const size_t size = 1 * 1024 * 1024 * 1024ul;
const size_t chunk_size = 2 * 1024 * 1024ul;
int main(void)
{
struct hmm_dmirror_cmd cmd;
size_t cur_size;
int fd, ret;
char *addr, *mirror;
fd = open("/dev/hmm_dmirror1", O_RDWR, 0);
if (fd < 0) {
perror("open failed\n");
exit(1);
}
addr = mmap(NULL, size, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
if (addr == MAP_FAILED) {
perror("mmap failed\n");
exit(1);
}
madvise(addr, size, MADV_NOHUGEPAGE);
memset(addr, 1, size);
mirror = malloc(chunk_size);
for (cur_size = 0; cur_size < size; cur_size += chunk_size) {
cmd.addr = (uintptr_t)addr + cur_size;
cmd.ptr = (uintptr_t)mirror;
cmd.npages = chunk_size / getpagesize();
ret = ioctl(fd, HMM_DMIRROR_EXCLUSIVE, &cmd);
if (ret) {
perror("ioctl failed\n");
exit(1);
}
}
pause();
return 0;
}
</program>
[1] https://lkml.kernel.org/r/25e02685-4f1d-47fa-be5b-01ff85bb0ce2@redhat.com
This patch (of 17):
We only have two FOLL_SPLIT_PMD users. While uprobe refuses hugetlb
early, make_device_exclusive_range() can end up getting called on hugetlb
VMAs.
Right now, this means that with a PMD-sized hugetlb page, we can end up
calling split_huge_pmd(), because pmd_trans_huge() also succeeds with
hugetlb PMDs.
For example, using a modified hmm-test selftest one can trigger:
[ 207.017134][T14945] ------------[ cut here ]------------
[ 207.018614][T14945] kernel BUG at mm/page_table_check.c:87!
[ 207.019716][T14945] Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI
[ 207.021072][T14945] CPU: 3 UID: 0 PID: ...
[ 207.023036][T14945] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-2.fc40 04/01/2014
[ 207.024834][T14945] RIP: 0010:page_table_check_clear.part.0+0x488/0x510
[ 207.026128][T14945] Code: ...
[ 207.029965][T14945] RSP: 0018:ffffc9000cb8f348 EFLAGS: 00010293
[ 207.031139][T14945] RAX: 0000000000000000 RBX: 00000000ffffffff RCX: ffffffff8249a0cd
[ 207.032649][T14945] RDX: ffff88811e883c80 RSI: ffffffff8249a357 RDI: ffff88811e883c80
[ 207.034183][T14945] RBP: ffff888105c0a050 R08: 0000000000000005 R09: 0000000000000000
[ 207.035688][T14945] R10: 00000000ffffffff R11: 0000000000000003 R12: 0000000000000001
[ 207.037203][T14945] R13: 0000000000000200 R14: 0000000000000001 R15: dffffc0000000000
[ 207.038711][T14945] FS: 00007f2783275740(0000) GS:ffff8881f4980000(0000) knlGS:0000000000000000
[ 207.040407][T14945] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 207.041660][T14945] CR2: 00007f2782c00000 CR3: 0000000132356000 CR4: 0000000000750ef0
[ 207.043196][T14945] PKRU: 55555554
[ 207.043880][T14945] Call Trace:
[ 207.044506][T14945] <TASK>
[ 207.045086][T14945] ? __die+0x51/0x92
[ 207.045864][T14945] ? die+0x29/0x50
[ 207.046596][T14945] ? do_trap+0x250/0x320
[ 207.047430][T14945] ? do_error_trap+0xe7/0x220
[ 207.048346][T14945] ? page_table_check_clear.part.0+0x488/0x510
[ 207.049535][T14945] ? handle_invalid_op+0x34/0x40
[ 207.050494][T14945] ? page_table_check_clear.part.0+0x488/0x510
[ 207.051681][T14945] ? exc_invalid_op+0x2e/0x50
[ 207.052589][T14945] ? asm_exc_invalid_op+0x1a/0x20
[ 207.053596][T14945] ? page_table_check_clear.part.0+0x1fd/0x510
[ 207.054790][T14945] ? page_table_check_clear.part.0+0x487/0x510
[ 207.055993][T14945] ? page_table_check_clear.part.0+0x488/0x510
[ 207.057195][T14945] ? page_table_check_clear.part.0+0x487/0x510
[ 207.058384][T14945] __page_table_check_pmd_clear+0x34b/0x5a0
[ 207.059524][T14945] ? __pfx___page_table_check_pmd_clear+0x10/0x10
[ 207.060775][T14945] ? __pfx___mutex_unlock_slowpath+0x10/0x10
[ 207.061940][T14945] ? __pfx___lock_acquire+0x10/0x10
[ 207.062967][T14945] pmdp_huge_clear_flush+0x279/0x360
[ 207.064024][T14945] split_huge_pmd_locked+0x82b/0x3750
...
Before commit 9cb28da ("mm/gup: handle hugetlb in the generic
follow_page_mask code"), we would have ignored the flag; instead, let's
simply refuse the combination completely in check_vma_flags(): the caller
is likely not prepared to handle any hugetlb folios.
We'll teach make_device_exclusive_range() separately to ignore any hugetlb
folios as a future-proof safety net.
Link: https://lkml.kernel.org/r/20250210193801.781278-1-david@redhat.com
Link: https://lkml.kernel.org/r/20250210193801.781278-2-david@redhat.com
Fixes: 9cb28da ("mm/gup: handle hugetlb in the generic follow_page_mask code")
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Alistair Popple <apopple@nvidia.com>
Tested-by: Alistair Popple <apopple@nvidia.com>
Cc: Alex Shi <alexs@kernel.org>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: Dave Airlie <airlied@gmail.com>
Cc: Jann Horn <jannh@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Karol Herbst <kherbst@redhat.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Lyude <lyude@redhat.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: SeongJae Park <sj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yanteng Si <si.yanteng@linux.dev>
Cc: Simona Vetter <simona.vetter@ffwll.ch>
Cc: Barry Song <v-songbaohua@oppo.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
akiyks
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Patch series "Fix lazy mmu mode", v2. I'm planning to implement lazy mmu mode for arm64 to optimize vmalloc. As part of that, I will extend lazy mmu mode to cover kernel mappings in vmalloc table walkers. While lazy mmu mode is already used for kernel mappings in a few places, this will extend it's use significantly. Having reviewed the existing lazy mmu implementations in powerpc, sparc and x86, it looks like there are a bunch of bugs, some of which may be more likely to trigger once I extend the use of lazy mmu. So this series attempts to clarify the requirements and fix all the bugs in advance of that series. See patch #1 commit log for all the details. This patch (of 5): The docs, implementations and use of arch_[enter|leave]_lazy_mmu_mode() is a bit of a mess (to put it politely). There are a number of issues related to nesting of lazy mmu regions and confusion over whether the task, when in a lazy mmu region, is preemptible or not. Fix all the issues relating to the core-mm. Follow up commits will fix the arch-specific implementations. 3 arches implement lazy mmu; powerpc, sparc and x86. When arch_[enter|leave]_lazy_mmu_mode() was first introduced by commit 6606c3e ("[PATCH] paravirt: lazy mmu mode hooks.patch"), it was expected that lazy mmu regions would never nest and that the appropriate page table lock(s) would be held while in the region, thus ensuring the region is non-preemptible. Additionally lazy mmu regions were only used during manipulation of user mappings. Commit 38e0edb ("mm/apply_to_range: call pte function with lazy updates") started invoking the lazy mmu mode in apply_to_pte_range(), which is used for both user and kernel mappings. For kernel mappings the region is no longer protected by any lock so there is no longer any guarantee about non-preemptibility. Additionally, for RT configs, the holding the PTL only implies no CPU migration, it doesn't prevent preemption. Commit bcc6cc8 ("mm: add default definition of set_ptes()") added arch_[enter|leave]_lazy_mmu_mode() to the default implementation of set_ptes(), used by x86. So after this commit, lazy mmu regions can be nested. Additionally commit 1a10a44 ("sparc64: implement the new page table range API") and commit 9fee28b ("powerpc: implement the new page table range API") did the same for the sparc and powerpc set_ptes() overrides. powerpc couldn't deal with preemption so avoids it in commit b9ef323 ("powerpc/64s: Disable preemption in hash lazy mmu mode"), which explicitly disables preemption for the whole region in its implementation. x86 can support preemption (or at least it could until it tried to add support nesting; more on this below). Sparc looks to be totally broken in the face of preemption, as far as I can tell. powerpc can't deal with nesting, so avoids it in commit 47b8def ("powerpc/mm: Avoid calling arch_enter/leave_lazy_mmu() in set_ptes"), which removes the lazy mmu calls from its implementation of set_ptes(). x86 attempted to support nesting in commit 49147be ("x86/xen: allow nesting of same lazy mode") but as far as I can tell, this breaks its support for preemption. In short, it's all a mess; the semantics for arch_[enter|leave]_lazy_mmu_mode() are not clearly defined and as a result the implementations all have different expectations, sticking plasters and bugs. arm64 is aiming to start using these hooks, so let's clean everything up before adding an arm64 implementation. Update the documentation to state that lazy mmu regions can never be nested, must not be called in interrupt context and preemption may or may not be enabled for the duration of the region. And fix the generic implementation of set_ptes() to avoid nesting. arch-specific fixes to conform to the new spec will proceed this one. These issues were spotted by code review and I have no evidence of issues being reported in the wild. Link: https://lkml.kernel.org/r/20250303141542.3371656-1-ryan.roberts@arm.com Link: https://lkml.kernel.org/r/20250303141542.3371656-2-ryan.roberts@arm.com Fixes: bcc6cc8 ("mm: add default definition of set_ptes()") Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Juergen Gross <jgross@suse.com> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Borislav Betkov <bp@alien8.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David S. Miller <davem@davemloft.net> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Juegren Gross <jgross@suse.com> Cc: Matthew Wilcow (Oracle) <willy@infradead.org> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
akiyks
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…ge_order() Patch series "mm: MM owner tracking for large folios (!hugetlb) + CONFIG_NO_PAGE_MAPCOUNT", v3. Let's add an "easy" way to decide -- without false positives, without page-mapcounts and without page table/rmap scanning -- whether a large folio is "certainly mapped exclusively" into a single MM, or whether it "maybe mapped shared" into multiple MMs. Use that information to implement Copy-on-Write reuse, to convert folio_likely_mapped_shared() to folio_maybe_mapped_share(), and to introduce a kernel config option that lets us not use+maintain per-page mapcounts in large folios anymore. The bigger picture was presented at LSF/MM [1]. This series is effectively a follow-up on my early work [2], which implemented a more precise, but also more complicated, way to identify whether a large folio is "mapped shared" into multiple MMs or "mapped exclusively" into a single MM. 1 Patch Organization ==================== Patch #1 -> torvalds#6: make more room in order-1 folios, so we have two "unsigned long" available for our purposes Patch torvalds#7 -> torvalds#11: preparations Patch torvalds#12: MM owner tracking for large folios Patch torvalds#13: COW reuse for PTE-mapped anon THP Patch torvalds#14: folio_maybe_mapped_shared() Patch torvalds#15 -> torvalds#20: introduce and implement CONFIG_NO_PAGE_MAPCOUNT 2 MM owner tracking =================== We assign each MM a unique ID ("MM ID"), to be able to squeeze more information in our folios. On 32bit we use 15-bit IDs, on 64bit we use 31-bit IDs. For each large folios, we now store two MM-ID+mapcount ("slot") combinations: * mm0_id + mm0_mapcount * mm1_id + mm1_mapcount On 32bit, we use a 16-bit per-MM mapcount, on 64bit an ordinary 32bit mapcount. This way, we require 2x "unsigned long" on 32bit and 64bit for both slots. Paired with the large mapcount, we can reliably identify whether one of these MMs is the current owner (-> owns all mappings) or even holds all folio references (-> owns all mappings, and all references are from mappings). As long as only two MMs map folio pages at a time, we can reliably and precisely identify whether a large folio is "mapped shared" or "mapped exclusively". Any additional MM that starts mapping the folio while there are no free slots becomes an "untracked MM". If one such "untracked MM" is the last one mapping a folio exclusively, we will not detect the folio as "mapped exclusively" but instead as "maybe mapped shared". (exception: only a single mapping remains) So that's where the approach gets imprecise. For now, we use a bit-spinlock to sync the large mapcount + slots, and make sure we do keep the machinery fast, to not degrade (un)map performance drastically: for example, we make sure to only use a single atomic (when grabbing the bit-spinlock), like we would already perform when updating the large mapcount. 3 CONFIG_NO_PAGE_MAPCOUNT ========================= patch torvalds#15 -> torvalds#20 spell out and document what exactly is affected when not maintaining the per-page mapcounts in large folios anymore. Most importantly, as we cannot maintain folio->_nr_pages_mapped anymore when (un)mapping pages, we'll account a complete folio as mapped if a single page is mapped. In addition, we'll not detect partially mapped anonymous folios as such in all cases yet. Likely less relevant changes include that we might now under-estimate the USS (Unique Set Size) of a process, but never over-estimate it. The goal is to make CONFIG_NO_PAGE_MAPCOUNT the default at some point, to then slowly make it the only option, as we learn about real-life impacts and possible ways to mitigate them. 4 Performance ============= Detailed performance numbers were included in v1 [3], and not that much changed between v1 and v2. I did plenty of measurements on different systems in the meantime, that all revealed slightly different results. The pte-mapped-folio micro-benchmarks [4] are fairly sensitive to code layout changes on some systems. Especially the fork() benchmark started being more-shaky-than-before on recent kernels for some reason. In summary, with my micro-benchmarks: * Small folios are not impacted. * CoW performance seems to be mostly unchanged across all folios sizes. * CoW reuse performance of large folios now matches CoW reuse performance of small folios, because we now actually implement the CoW reuse optimization. On an Intel Xeon Silver 4210R I measured a ~65% reduction in runtime, on an arm64 system I measured ~54% reduction. * munmap() performance improves with CONFIG_NO_PAGE_MAPCOUNT. I saw double-digit % reduction (up to ~30% on an Intel Xeon Silver 4210R and up to ~70% on an AmpereOne A192-32X) with larger folios. The larger the folios, the larger the performance improvement. * munmao() performance very slightly (couple percent) degrades without CONFIG_NO_PAGE_MAPCOUNT for smaller folios. For larger folios, there seems to be no change at all. * fork() performance improves with CONFIG_NO_PAGE_MAPCOUNT. I saw double-digit % reduction (up to ~20% on an Intel Xeon Silver 4210R and up to ~10% on an AmpereOne A192-32X) with larger folios. The larger the folios, the larger the performance improvement. * While fork() performance without CONFIG_NO_PAGE_MAPCOUNT seems to be almost unchanged on some systems, I saw some degradation for smaller folios on the AmpereOne A192-32X. I did not investigate the details yet, but I suspect code layout changes or suboptimal code placement / inlining. I'm not to worried about the fork() micro-benchmarks for smaller folios given how shaky the results are lately and by how much we improved fork() performance recently. I also ran case-anon-cow-rand and case-anon-cow-seq part of vm-scalability, to assess the scalability and the impact of the bit-spinlock. My measurements on a two 2-socket 10-core Intel Xeon Silver 4210R CPU revealed no significant changes. Similarly, running these benchmarks with 2 MiB THPs enabled on the AmpereOne A192-32X with 192 cores, I got < 1% difference with < 1% stdev, which is nice. So far, I did not get my hands on a similarly large system with multiple sockets. I found no other fitting scalability benchmarks that seem to really hammer on concurrent mapping/unmapping of large folio pages like case-anon-cow-seq does. 5 Concerns ========== 5.1 Bit spinlock ---------------- I'm not quite happy about the bit-spinlock, but so far it does not seem to affect scalability in my measurements. If it ever becomes a problem we could either investigate improving the locking, or simply stopping the MM tracking once there are "too many mappings" and simply assume that the folio is "mapped shared" until it was freed. This would be similar (but slightly different) to the "0,1,2,stopped" counting idea Willy had at some point. Adding that logic to "stop tracking" adds more code to the hot path, so I avoided that for now. 5.2 folio_maybe_mapped_shared() ------------------------------- I documented the change from folio_likely_mapped_shared() to folio_maybe_mapped_shared() quite extensively. If we run into surprises, I have some ideas on how to resolve them. For now, I think we should be fine. 5.3 Added code to map/unmap hot path ------------------------------------ So far, it looks like the added code on the rmap hot path does not really seem to matter much in the bigger picture. I'd like to further reduce it (and possibly improve fork() performance further), but I don't easily see how right now. Well, and I am out of puff 🙂 Having that said, alternatives I considered (e.g., per-MM per-folio mapcount) would add a lot more overhead to these hot paths. 6 Future Work ============= 6.1 Large mapcount ------------------ It would be very handy if the large mapcount would count how often folio pages are actually mapped into page tables: a PMD on x86-64 would count 512 times. Calculating the average per-page mapcount will be easy, and remapping (PMD->PTE) folios would get even faster. That would also remove the need for the entire mapcount (except for PMD-sized folios for memory statistics reasons ...), and allow for mapping folios larger than PMDs (e.g., 4 MiB) easily. We likely would also have to take the same number of folio references to make our folio_mapcount() == folio_ref_count() work, and we'd want to be able to avoid mapcount+refcount overflows: this could already become an issue with pte-mapped PUD-sized folios (fsdax). One approach we discussed in the THP cabal meeting is (1) extending the mapcount for large folios to 64bit (at least on 64bit systems) and (2) keeping the refcount at 32bit, but (3) having exactly one reference if the the mapcount != 0. It should be doable, but there are some corner cases to consider on the unmap path; it is something that I will be looking into next. 6.2 hugetlb ----------- I'd love to make use of the same tracking also for hugetlb. The real problem is PMD table sharing: getting a page mapped by MM X and unmapped by MM Y will not work. With mshare, that problem should not exist (all mapping/unmapping will be routed through the mshare MM). [1] https://lwn.net/Articles/974223/ [2] https://lore.kernel.org/linux-mm/a9922f58-8129-4f15-b160-e0ace581bcbe@redhat.com/T/ [3] https://lkml.kernel.org/r/20240829165627.2256514-1-david@redhat.com [4] https://gitlab.com/davidhildenbrand/scratchspace/-/raw/main/pte-mapped-folio-benchmarks.c This patch (of 20): Let's factor it out into a simple helper function. This helper will also come in handy when working with code where we know that our folio is large. Maybe in the future we'll have the order readily available for small and large folios; in that case, folio_large_order() would simply translate to folio_order(). Link: https://lkml.kernel.org/r/20250303163014.1128035-1-david@redhat.com Link: https://lkml.kernel.org/r/20250303163014.1128035-2-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Lance Yang <ioworker0@gmail.com> Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirks^H^Hski <luto@kernel.org> Cc: Borislav Betkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Matthew Wilcow (Oracle) <willy@infradead.org> Cc: Michal Koutn <mkoutny@suse.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: tejun heo <tj@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zefan Li <lizefan.x@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
akiyks
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Patch series "mm: reliable huge page allocator". This series makes changes to the allocator and reclaim/compaction code to try harder to avoid fragmentation. As a result, this makes huge page allocations cheaper, more reliable and more sustainable. It's a subset of the huge page allocator RFC initially proposed here: https://lore.kernel.org/lkml/20230418191313.268131-1-hannes@cmpxchg.org/ The following results are from a kernel build test, with additional concurrent bursts of THP allocations on a memory-constrained system. Comparing before and after the changes over 15 runs: before after Hugealloc Time mean 52739.45 ( +0.00%) 28904.00 ( -45.19%) Hugealloc Time stddev 56541.26 ( +0.00%) 33464.37 ( -40.81%) Kbuild Real time 197.47 ( +0.00%) 196.59 ( -0.44%) Kbuild User time 1240.49 ( +0.00%) 1231.67 ( -0.71%) Kbuild System time 70.08 ( +0.00%) 59.10 ( -15.45%) THP fault alloc 46727.07 ( +0.00%) 63223.67 ( +35.30%) THP fault fallback 21910.60 ( +0.00%) 5412.47 ( -75.29%) Direct compact fail 195.80 ( +0.00%) 59.07 ( -69.48%) Direct compact success 7.93 ( +0.00%) 2.80 ( -57.46%) Direct compact success rate % 3.51 ( +0.00%) 3.99 ( +10.49%) Compact daemon scanned migrate 3369601.27 ( +0.00%) 2267500.33 ( -32.71%) Compact daemon scanned free 5075474.47 ( +0.00%) 2339773.00 ( -53.90%) Compact direct scanned migrate 161787.27 ( +0.00%) 47659.93 ( -70.54%) Compact direct scanned free 163467.53 ( +0.00%) 40729.67 ( -75.08%) Compact total migrate scanned 3531388.53 ( +0.00%) 2315160.27 ( -34.44%) Compact total free scanned 5238942.00 ( +0.00%) 2380502.67 ( -54.56%) Alloc stall 2371.07 ( +0.00%) 638.87 ( -73.02%) Pages kswapd scanned 2160926.73 ( +0.00%) 4002186.33 ( +85.21%) Pages kswapd reclaimed 533191.07 ( +0.00%) 718577.80 ( +34.77%) Pages direct scanned 400450.33 ( +0.00%) 355172.73 ( -11.31%) Pages direct reclaimed 94441.73 ( +0.00%) 31162.80 ( -67.00%) Pages total scanned 2561377.07 ( +0.00%) 4357359.07 ( +70.12%) Pages total reclaimed 627632.80 ( +0.00%) 749740.60 ( +19.46%) Swap out 47959.53 ( +0.00%) 110084.33 ( +129.53%) Swap in 7276.00 ( +0.00%) 24457.00 ( +236.10%) File refaults 138043.00 ( +0.00%) 188226.93 ( +36.35%) THP latencies are cut in half, and failure rates are cut by 75%. These metrics also hold up over time, while the vanilla kernel sees a steady downward trend in success rates with each subsequent run, owed to the cumulative effects of fragmentation. A more detailed discussion of results is in the patch changelogs. The patches first introduce a vm.defrag_mode sysctl, which enforces the existing ALLOC_NOFRAGMENT alloc flag until after reclaim and compaction have run. They then change kswapd and kcompactd to target pageblocks, which boosts success in the ALLOC_NOFRAGMENT hotpaths. Patches #1 and #2 are somewhat unrelated cleanups, but touch the same code and so are included here to avoid conflicts from re-ordering. This patch (of 5): compaction_suitable() hardcodes the min watermark, with a boost to the low watermark for costly orders. However, compaction_ready() requires order-0 at the high watermark. It currently checks the marks twice. Make the watermark a parameter to compaction_suitable() and have the callers pass in what they require: - compaction_zonelist_suitable() is used by the direct reclaim path, so use the min watermark. - compact_suit_allocation_order() has a watermark in context derived from cc->alloc_flags. The only quirk is that kcompactd doesn't initialize cc->alloc_flags explicitly. There is a direct check in kcompactd_do_work() that passes ALLOC_WMARK_MIN, but there is another check downstack in compact_zone() that ends up passing the unset alloc_flags. Since they default to 0, and that coincides with ALLOC_WMARK_MIN, it is correct. But it's subtle. Set cc->alloc_flags explicitly. - should_continue_reclaim() is direct reclaim, use the min watermark. - Finally, consolidate the two checks in compaction_ready() to a single compaction_suitable() call passing the high watermark. There is a tiny change in behavior: before, compaction_suitable() would check order-0 against min or low, depending on costly order. Then there'd be another high watermark check. Now, the high watermark is passed to compaction_suitable(), and the costly order-boost (low - min) is added on top. This means compaction_ready() sets a marginally higher target for free pages. In a kernelbuild + THP pressure test, though, this didn't show any measurable negative effects on memory pressure or reclaim rates. As the comment above the check says, reclaim is usually stopped short on should_continue_reclaim(), and this just defines the worst-case reclaim cutoff in case compaction is not making any headway. [hughd@google.com: stop oops on out-of-range highest_zoneidx] Link: https://lkml.kernel.org/r/005ace8b-07fa-01d4-b54b-394a3e029c07@google.com Link: https://lkml.kernel.org/r/20250313210647.1314586-1-hannes@cmpxchg.org Link: https://lkml.kernel.org/r/20250313210647.1314586-2-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Zi Yan <ziy@nvidia.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Syzkaller reports a bug as follows: Injecting memory failure for pfn 0x18b00e at process virtual address 0x20ffd000 Memory failure: 0x18b00e: dirty swapcache page still referenced by 2 users Memory failure: 0x18b00e: recovery action for dirty swapcache page: Failed page: refcount:2 mapcount:0 mapping:0000000000000000 index:0x20ffd pfn:0x18b00e memcg:ffff0000dd6d9000 anon flags: 0x5ffffe00482011(locked|dirty|arch_1|swapbacked|hwpoison|node=0|zone=2|lastcpupid=0xfffff) raw: 005ffffe00482011 dead000000000100 dead000000000122 ffff0000e232a7c9 raw: 0000000000020ffd 0000000000000000 00000002ffffffff ffff0000dd6d9000 page dumped because: VM_BUG_ON_FOLIO(!folio_test_uptodate(folio)) ------------[ cut here ]------------ kernel BUG at mm/swap_state.c:184! Internal error: Oops - BUG: 00000000f2000800 [#1] SMP Modules linked in: CPU: 0 PID: 60 Comm: kswapd0 Not tainted 6.6.0-gcb097e7de84e #3 Hardware name: linux,dummy-virt (DT) pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : add_to_swap+0xbc/0x158 lr : add_to_swap+0xbc/0x158 sp : ffff800087f37340 x29: ffff800087f37340 x28: fffffc00052c0380 x27: ffff800087f37780 x26: ffff800087f37490 x25: ffff800087f37c78 x24: ffff800087f377a0 x23: ffff800087f37c50 x22: 0000000000000000 x21: fffffc00052c03b4 x20: 0000000000000000 x19: fffffc00052c0380 x18: 0000000000000000 x17: 296f696c6f662865 x16: 7461646f7470755f x15: 747365745f6f696c x14: 6f6621284f494c4f x13: 0000000000000001 x12: ffff600036d8b97b x11: 1fffe00036d8b97a x10: ffff600036d8b97a x9 : dfff800000000000 x8 : 00009fffc9274686 x7 : ffff0001b6c5cbd3 x6 : 0000000000000001 x5 : ffff0000c25896c0 x4 : 0000000000000000 x3 : 0000000000000000 x2 : 0000000000000000 x1 : ffff0000c25896c0 x0 : 0000000000000000 Call trace: add_to_swap+0xbc/0x158 shrink_folio_list+0x12ac/0x2648 shrink_inactive_list+0x318/0x948 shrink_lruvec+0x450/0x720 shrink_node_memcgs+0x280/0x4a8 shrink_node+0x128/0x978 balance_pgdat+0x4f0/0xb20 kswapd+0x228/0x438 kthread+0x214/0x230 ret_from_fork+0x10/0x20 I can reproduce this issue with the following steps: 1) When a dirty swapcache page is isolated by reclaim process and the page isn't locked, inject memory failure for the page. me_swapcache_dirty() clears uptodate flag and tries to delete from lru, but fails. Reclaim process will put the hwpoisoned page back to lru. 2) The process that maps the hwpoisoned page exits, the page is deleted the page will never be freed and will be in the lru forever. 3) If we trigger a reclaim again and tries to reclaim the page, add_to_swap() will trigger VM_BUG_ON_FOLIO due to the uptodate flag is cleared. To fix it, skip the hwpoisoned page in shrink_folio_list(). Besides, the hwpoison folio may not be unmapped by hwpoison_user_mappings() yet, unmap it in shrink_folio_list(), otherwise the folio will fail to be unmaped by hwpoison_user_mappings() since the folio isn't in lru list. Link: https://lkml.kernel.org/r/20250318083939.987651-3-tujinjiang@huawei.com Signed-off-by: Jinjiang Tu <tujinjiang@huawei.com> Acked-by: Miaohe Lin <linmiaohe@huawei.com> Cc: David Hildenbrand <david@redhat.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Nanyong Sun <sunnanyong@huawei.com> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: <stable@vger,kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Kernel test robot reports the following crash on 32-bit system with HIGHMEM and DEBUG_VIRTUAL: [ 0.056128][ T0] kernel BUG at arch/x86/mm/physaddr.c:77! PANIC: early exception 0x06 IP 60:c116539d error 0 cr2 0x0 [ 0.056916][ T0] CPU: 0 UID: 0 PID: 0 Comm: swapper Not tainted 6.14.0-rc4-00010-ga4dbe5c71817 #1 [ 0.057570][ T0] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 [ 0.058299][ T0] EIP: __phys_addr (arch/x86/mm/physaddr.c:77) [ 0.058633][ T0] Code: 00 74 33 89 f0 e8 d3 8b 2e 00 89 c3 0f b6 d0 b8 58 bb 4b c5 31 c9 6a 00 e8 70 f5 15 00 83 c4 04 84 db 74 25 ff 05 78 de 5d c5 <0f> 0b b8 c8 91 ea c4 e8 e7 6e ea ff b8 58 bb 4b c5 31 d2 31 c9 6a All code [ 0.060017][ T0] EAX: 00000000 EBX: c61f7001 ECX: 00000000 EDX: 00000000 [ 0.060519][ T0] ESI: c61f7000 EDI: 061f7000 EBP: c4e31f04 ESP: c61f7000 [ 0.061016][ T0] DS: 007b ES: 007b FS: 0000 GS: 0000 SS: cff4 EFLAGS: 00210002 [ 0.061560][ T0] CR0: 80050033 CR2: 00000000 CR3: 059fc000 CR4: 00000090 [ 0.062060][ T0] Call Trace: [ 0.062288][ T0] ? show_regs (arch/x86/kernel/dumpstack.c:478) [ 0.062588][ T0] ? early_fixup_exception (arch/x86/include/asm/nospec-branch.h:595) [ 0.062968][ T0] ? early_idt_handler_common (arch/x86/kernel/head_32.S:352) [ 0.063360][ T0] ? __phys_addr (arch/x86/mm/physaddr.c:77) [ 0.063677][ T0] ? one_page_table_init (arch/x86/mm/init_32.c:100) [ 0.064037][ T0] ? page_table_range_init (arch/x86/mm/init_32.c:227) [ 0.064411][ T0] ? permanent_kmaps_init (include/linux/pgtable.h:191 include/linux/pgtable.h:196 arch/x86/mm/init_32.c:395) [ 0.064814][ T0] ? paging_init (arch/x86/mm/init_32.c:677) [ 0.065118][ T0] ? native_pagetable_init (arch/x86/mm/init_32.c:481) [ 0.065503][ T0] ? setup_arch (arch/x86/kernel/setup.c:1131) [ 0.065819][ T0] ? start_kernel (include/linux/jump_label.h:267 init/main.c:920) [ 0.066143][ T0] ? i386_start_kernel (arch/x86/kernel/head32.c:79) [ 0.066501][ T0] ? startup_32_smp (arch/x86/kernel/head_32.S:292) The crash happens because commit e120d1b ("arch, mm: set high_memory in free_area_init()") moved initialization of high_memory after __vmalloc_start_set and with high_memory still set to 0 any address passes is_vmalloc_addr() check. Restore early initialization of high_memory on 32-bit systems in initmem_init(). Link: https://lkml.kernel.org/r/20250319122337.1538924-1-rppt@kernel.org Fixes: e120d1b ("arch, mm: set high_memory in free_area_init()") Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Reported-by: kernel test robot <oliver.sang@intel.com> Closes: https://lore.kernel.org/oe-lkp/202503191442.112e954f-lkp@intel.com Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Betkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleinxer <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Commit 30aad41 ("net/core: Add support for getting VF GUIDs") added support for getting VF port and node GUIDs in netlink ifinfo messages, but their size was not taken into consideration in the function that allocates the netlink message, causing the following warning when a netlink message is filled with many VF port and node GUIDs: # echo 64 > /sys/bus/pci/devices/0000\:08\:00.0/sriov_numvfs # ip link show dev ib0 RTNETLINK answers: Message too long Cannot send link get request: Message too long Kernel warning: ------------[ cut here ]------------ WARNING: CPU: 2 PID: 1930 at net/core/rtnetlink.c:4151 rtnl_getlink+0x586/0x5a0 Modules linked in: xt_conntrack xt_MASQUERADE nfnetlink xt_addrtype iptable_nat nf_nat br_netfilter overlay mlx5_ib macsec mlx5_core tls rpcrdma rdma_ucm ib_uverbs ib_iser libiscsi scsi_transport_iscsi ib_umad rdma_cm iw_cm ib_ipoib fuse ib_cm ib_core CPU: 2 UID: 0 PID: 1930 Comm: ip Not tainted 6.14.0-rc2+ #1 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 RIP: 0010:rtnl_getlink+0x586/0x5a0 Code: cb 82 e8 3d af 0a 00 4d 85 ff 0f 84 08 ff ff ff 4c 89 ff 41 be ea ff ff ff e8 66 63 5b ff 49 c7 07 80 4f cb 82 e9 36 fc ff ff <0f> 0b e9 16 fe ff ff e8 de a0 56 00 66 66 2e 0f 1f 84 00 00 00 00 RSP: 0018:ffff888113557348 EFLAGS: 00010246 RAX: 00000000ffffffa6 RBX: ffff88817e87aa34 RCX: dffffc0000000000 RDX: 0000000000000003 RSI: 0000000000000000 RDI: ffff88817e87afb8 RBP: 0000000000000009 R08: ffffffff821f44aa R09: 0000000000000000 R10: ffff8881260f79a8 R11: ffff88817e87af00 R12: ffff88817e87aa00 R13: ffffffff8563d300 R14: 00000000ffffffa6 R15: 00000000ffffffff FS: 00007f63a5dbf280(0000) GS:ffff88881ee00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f63a5ba4493 CR3: 00000001700fe002 CR4: 0000000000772eb0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: <TASK> ? __warn+0xa5/0x230 ? rtnl_getlink+0x586/0x5a0 ? report_bug+0x22d/0x240 ? handle_bug+0x53/0xa0 ? exc_invalid_op+0x14/0x50 ? asm_exc_invalid_op+0x16/0x20 ? skb_trim+0x6a/0x80 ? rtnl_getlink+0x586/0x5a0 ? __pfx_rtnl_getlink+0x10/0x10 ? rtnetlink_rcv_msg+0x1e5/0x860 ? __pfx___mutex_lock+0x10/0x10 ? rcu_is_watching+0x34/0x60 ? __pfx_lock_acquire+0x10/0x10 ? stack_trace_save+0x90/0xd0 ? filter_irq_stacks+0x1d/0x70 ? kasan_save_stack+0x30/0x40 ? kasan_save_stack+0x20/0x40 ? kasan_save_track+0x10/0x30 rtnetlink_rcv_msg+0x21c/0x860 ? entry_SYSCALL_64_after_hwframe+0x76/0x7e ? __pfx_rtnetlink_rcv_msg+0x10/0x10 ? arch_stack_walk+0x9e/0xf0 ? rcu_is_watching+0x34/0x60 ? lock_acquire+0xd5/0x410 ? rcu_is_watching+0x34/0x60 netlink_rcv_skb+0xe0/0x210 ? __pfx_rtnetlink_rcv_msg+0x10/0x10 ? __pfx_netlink_rcv_skb+0x10/0x10 ? rcu_is_watching+0x34/0x60 ? __pfx___netlink_lookup+0x10/0x10 ? lock_release+0x62/0x200 ? netlink_deliver_tap+0xfd/0x290 ? rcu_is_watching+0x34/0x60 ? lock_release+0x62/0x200 ? netlink_deliver_tap+0x95/0x290 netlink_unicast+0x31f/0x480 ? __pfx_netlink_unicast+0x10/0x10 ? rcu_is_watching+0x34/0x60 ? lock_acquire+0xd5/0x410 netlink_sendmsg+0x369/0x660 ? lock_release+0x62/0x200 ? __pfx_netlink_sendmsg+0x10/0x10 ? import_ubuf+0xb9/0xf0 ? __import_iovec+0x254/0x2b0 ? lock_release+0x62/0x200 ? __pfx_netlink_sendmsg+0x10/0x10 ____sys_sendmsg+0x559/0x5a0 ? __pfx_____sys_sendmsg+0x10/0x10 ? __pfx_copy_msghdr_from_user+0x10/0x10 ? rcu_is_watching+0x34/0x60 ? do_read_fault+0x213/0x4a0 ? rcu_is_watching+0x34/0x60 ___sys_sendmsg+0xe4/0x150 ? __pfx____sys_sendmsg+0x10/0x10 ? do_fault+0x2cc/0x6f0 ? handle_pte_fault+0x2e3/0x3d0 ? __pfx_handle_pte_fault+0x10/0x10 ? preempt_count_sub+0x14/0xc0 ? __down_read_trylock+0x150/0x270 ? __handle_mm_fault+0x404/0x8e0 ? __pfx___handle_mm_fault+0x10/0x10 ? lock_release+0x62/0x200 ? __rcu_read_unlock+0x65/0x90 ? rcu_is_watching+0x34/0x60 __sys_sendmsg+0xd5/0x150 ? __pfx___sys_sendmsg+0x10/0x10 ? __up_read+0x192/0x480 ? lock_release+0x62/0x200 ? __rcu_read_unlock+0x65/0x90 ? rcu_is_watching+0x34/0x60 do_syscall_64+0x6d/0x140 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f63a5b13367 Code: 0e 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b9 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 89 54 24 1c 48 89 74 24 10 RSP: 002b:00007fff8c726bc8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000067b687c2 RCX: 00007f63a5b13367 RDX: 0000000000000000 RSI: 00007fff8c726c30 RDI: 0000000000000004 RBP: 00007fff8c726cb8 R08: 0000000000000000 R09: 0000000000000034 R10: 00007fff8c726c7c R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000000 R14: 00007fff8c726cd0 R15: 00007fff8c726cd0 </TASK> irq event stamp: 0 hardirqs last enabled at (0): [<0000000000000000>] 0x0 hardirqs last disabled at (0): [<ffffffff813f9e58>] copy_process+0xd08/0x2830 softirqs last enabled at (0): [<ffffffff813f9e58>] copy_process+0xd08/0x2830 softirqs last disabled at (0): [<0000000000000000>] 0x0 ---[ end trace 0000000000000000 ]--- Thus, when calculating ifinfo message size, take VF GUIDs sizes into account when supported. Fixes: 30aad41 ("net/core: Add support for getting VF GUIDs") Signed-off-by: Mark Zhang <markzhang@nvidia.com> Reviewed-by: Maher Sanalla <msanalla@nvidia.com> Signed-off-by: Mark Bloch <mbloch@nvidia.com> Reviewed-by: Sabrina Dubroca <sd@queasysnail.net> Link: https://patch.msgid.link/20250325090226.749730-1-mbloch@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Check if the pasid has been attached before going further in the detach path. This fixes a crash found by syzkaller. Add a selftest as well. Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASI KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] CPU: 1 UID: 0 PID: 668 Comm: repro Not tainted 6.14.0-next-20250325-eb4bc4b07f66 #1 PREEMPT(voluntary) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org4 RIP: 0010:iommufd_hw_pagetable_detach+0x8a/0x4d0 Code: 00 00 00 44 89 ee 48 89 c7 48 89 75 c8 48 89 45 c0 e8 ca 55 17 02 48 89 c2 49 89 c4 48 b8 00 00 00b RSP: 0018:ffff888021b17b78 EFLAGS: 00010246 RAX: dffffc0000000000 RBX: ffff888014b5a000 RCX: ffff888021b17a64 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88801dad07fc RBP: ffff888021b17bc8 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000000001 R11: ffff88801dad0e58 R12: 0000000000000000 R13: 0000000000000001 R14: ffff888021b17e18 R15: ffff8880132d3008 FS: 00007fca52013600(0000) GS:ffff8880e3684000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000200006c0 CR3: 00000000112d0005 CR4: 0000000000770ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff07f0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: <TASK> iommufd_device_detach+0x2a/0x2e0 iommufd_test+0x2f99/0x5cd0 iommufd_fops_ioctl+0x38e/0x520 __x64_sys_ioctl+0x1ba/0x220 x64_sys_call+0x122e/0x2150 do_syscall_64+0x6d/0x150 entry_SYSCALL_64_after_hwframe+0x76/0x7e Link: https://patch.msgid.link/r/20250328133448.22052-1-yi.l.liu@intel.com Reported-by: Lai Yi <yi1.lai@linux.intel.com> Closes: https://lore.kernel.org/linux-iommu/Z+X0tzxhiaupJT7b@ly-workstation Fixes: c0e301b ("iommufd/device: Add pasid_attach array to track per-PASID attach") Signed-off-by: Yi Liu <yi.l.liu@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
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syzbot reported a NULL pointer dereference in __generic_file_write_iter. [1] Before the write operation is completed, the user executes ioctl[2] to clear the compress flag of the file, which causes the is_compressed() judgment to return 0, further causing the program to enter the wrong process and call the wrong ops ntfs_aops_cmpr, which triggers the null pointer dereference of write_begin. Use inode lock to synchronize ioctl and write to avoid this case. [1] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 Mem abort info: ESR = 0x0000000086000006 EC = 0x21: IABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x06: level 2 translation fault user pgtable: 4k pages, 48-bit VAs, pgdp=000000011896d000 [0000000000000000] pgd=0800000118b44403, p4d=0800000118b44403, pud=0800000117517403, pmd=0000000000000000 Internal error: Oops: 0000000086000006 [#1] PREEMPT SMP Modules linked in: CPU: 0 UID: 0 PID: 6427 Comm: syz-executor347 Not tainted 6.13.0-rc3-syzkaller-g573067a5a685 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : 0x0 lr : generic_perform_write+0x29c/0x868 mm/filemap.c:4055 sp : ffff80009d4978a0 x29: ffff80009d4979c0 x28: dfff800000000000 x27: ffff80009d497bc8 x26: 0000000000000000 x25: ffff80009d497960 x24: ffff80008ba71c68 x23: 0000000000000000 x22: ffff0000c655dac0 x21: 0000000000001000 x20: 000000000000000c x19: 1ffff00013a92f2c x18: ffff0000e183aa1c x17: 0004060000000014 x16: ffff800083275834 x15: 0000000000000001 x14: 0000000000000000 x13: 0000000000000001 x12: ffff0000c655dac0 x11: 0000000000ff0100 x10: 0000000000ff0100 x9 : 0000000000000000 x8 : 0000000000000000 x7 : 0000000000000000 x6 : 0000000000000000 x5 : ffff80009d497980 x4 : ffff80009d497960 x3 : 0000000000001000 x2 : 0000000000000000 x1 : ffff0000e183a928 x0 : ffff0000d60b0fc0 Call trace: 0x0 (P) __generic_file_write_iter+0xfc/0x204 mm/filemap.c:4156 ntfs_file_write_iter+0x54c/0x630 fs/ntfs3/file.c:1267 new_sync_write fs/read_write.c:586 [inline] vfs_write+0x920/0xcf4 fs/read_write.c:679 ksys_write+0x15c/0x26c fs/read_write.c:731 __do_sys_write fs/read_write.c:742 [inline] __se_sys_write fs/read_write.c:739 [inline] __arm64_sys_write+0x7c/0x90 fs/read_write.c:739 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744 el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762 [2] ioctl$FS_IOC_SETFLAGS(r0, 0x40086602, &(0x7f00000000c0)=0x20) Reported-by: syzbot+5d0bdc98770e6c55a0fd@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=5d0bdc98770e6c55a0fd Signed-off-by: Lizhi Xu <lizhi.xu@windriver.com> Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
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Intel Merrifield SoC uses these endpoints for tracing and they cannot be re-allocated if being used because the side band flow control signals are hard wired to certain endpoints: • 1 High BW Bulk IN (IN#1) (RTIT) • 1 1KB BW Bulk IN (IN#8) + 1 1KB BW Bulk OUT (Run Control) (OUT#8) In device mode, since RTIT (EP#1) and EXI/RunControl (EP#8) uses External Buffer Control (EBC) mode, these endpoints are to be mapped to EBC mode (to be done by EXI target driver). Additionally TRB for RTIT and EXI are maintained in STM (System Trace Module) unit and the EXI target driver will as well configure the TRB location for EP #1 IN and EP#8 (IN and OUT). Since STM/PTI and EXI hardware blocks manage these endpoints and interface to OTG3 controller through EBC interface, there is no need to enable any events (such as XferComplete etc) for these end points. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Tested-by: Ferry Toth <fntoth@gmail.com> Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com> Link: https://lore.kernel.org/r/20250212193116.2487289-5-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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When a bio with REQ_PREFLUSH is submitted to dm, __send_empty_flush()
generates a flush_bio with REQ_OP_WRITE | REQ_PREFLUSH | REQ_SYNC,
which causes the flush_bio to be throttled by wbt_wait().
An example from v5.4, similar problem also exists in upstream:
crash> bt 2091206
PID: 2091206 TASK: ffff2050df92a300 CPU: 109 COMMAND: "kworker/u260:0"
#0 [ffff800084a2f7f0] __switch_to at ffff80004008aeb8
#1 [ffff800084a2f820] __schedule at ffff800040bfa0c4
#2 [ffff800084a2f880] schedule at ffff800040bfa4b4
#3 [ffff800084a2f8a0] io_schedule at ffff800040bfa9c4
#4 [ffff800084a2f8c0] rq_qos_wait at ffff8000405925bc
#5 [ffff800084a2f940] wbt_wait at ffff8000405bb3a0
torvalds#6 [ffff800084a2f9a0] __rq_qos_throttle at ffff800040592254
torvalds#7 [ffff800084a2f9c0] blk_mq_make_request at ffff80004057cf38
torvalds#8 [ffff800084a2fa60] generic_make_request at ffff800040570138
torvalds#9 [ffff800084a2fae0] submit_bio at ffff8000405703b4
torvalds#10 [ffff800084a2fb50] xlog_write_iclog at ffff800001280834 [xfs]
torvalds#11 [ffff800084a2fbb0] xlog_sync at ffff800001280c3c [xfs]
torvalds#12 [ffff800084a2fbf0] xlog_state_release_iclog at ffff800001280df4 [xfs]
torvalds#13 [ffff800084a2fc10] xlog_write at ffff80000128203c [xfs]
torvalds#14 [ffff800084a2fcd0] xlog_cil_push at ffff8000012846dc [xfs]
torvalds#15 [ffff800084a2fda0] xlog_cil_push_work at ffff800001284a2c [xfs]
torvalds#16 [ffff800084a2fdb0] process_one_work at ffff800040111d08
torvalds#17 [ffff800084a2fe00] worker_thread at ffff8000401121cc
torvalds#18 [ffff800084a2fe70] kthread at ffff800040118de4
After commit 2def284 ("xfs: don't allow log IO to be throttled"),
the metadata submitted by xlog_write_iclog() should not be throttled.
But due to the existence of the dm layer, throttling flush_bio indirectly
causes the metadata bio to be throttled.
Fix this by conditionally adding REQ_IDLE to flush_bio.bi_opf, which makes
wbt_should_throttle() return false to avoid wbt_wait().
Signed-off-by: Jinliang Zheng <alexjlzheng@tencent.com>
Reviewed-by: Tianxiang Peng <txpeng@tencent.com>
Reviewed-by: Hao Peng <flyingpeng@tencent.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
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A cache device failing to resume due to mapping errors should not be
retried, as the failure leaves a partially initialized policy object.
Repeating the resume operation risks triggering BUG_ON when reloading
cache mappings into the incomplete policy object.
Reproduce steps:
1. create a cache metadata consisting of 512 or more cache blocks,
with some mappings stored in the first array block of the mapping
array. Here we use cache_restore v1.0 to build the metadata.
cat <<EOF >> cmeta.xml
<superblock uuid="" block_size="128" nr_cache_blocks="512" \
policy="smq" hint_width="4">
<mappings>
<mapping cache_block="0" origin_block="0" dirty="false"/>
</mappings>
</superblock>
EOF
dmsetup create cmeta --table "0 8192 linear /dev/sdc 0"
cache_restore -i cmeta.xml -o /dev/mapper/cmeta --metadata-version=2
dmsetup remove cmeta
2. wipe the second array block of the mapping array to simulate
data degradations.
mapping_root=$(dd if=/dev/sdc bs=1c count=8 skip=192 \
2>/dev/null | hexdump -e '1/8 "%u\n"')
ablock=$(dd if=/dev/sdc bs=1c count=8 skip=$((4096*mapping_root+2056)) \
2>/dev/null | hexdump -e '1/8 "%u\n"')
dd if=/dev/zero of=/dev/sdc bs=4k count=1 seek=$ablock
3. try bringing up the cache device. The resume is expected to fail
due to the broken array block.
dmsetup create cmeta --table "0 8192 linear /dev/sdc 0"
dmsetup create cdata --table "0 65536 linear /dev/sdc 8192"
dmsetup create corig --table "0 524288 linear /dev/sdc 262144"
dmsetup create cache --notable
dmsetup load cache --table "0 524288 cache /dev/mapper/cmeta \
/dev/mapper/cdata /dev/mapper/corig 128 2 metadata2 writethrough smq 0"
dmsetup resume cache
4. try resuming the cache again. An unexpected BUG_ON is triggered
while loading cache mappings.
dmsetup resume cache
Kernel logs:
(snip)
------------[ cut here ]------------
kernel BUG at drivers/md/dm-cache-policy-smq.c:752!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 332 Comm: dmsetup Not tainted 6.13.4 #3
RIP: 0010:smq_load_mapping+0x3e5/0x570
Fix by disallowing resume operations for devices that failed the
initial attempt.
Signed-off-by: Ming-Hung Tsai <mtsai@redhat.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
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If a faulty CXL memory device returns a broken zero LSA size in its memory device information (Identify Memory Device (Opcode 4000h), CXL spec. 3.1, 8.2.9.9.1.1), a divide error occurs in the libnvdimm driver: Oops: divide error: 0000 [#1] PREEMPT SMP NOPTI RIP: 0010:nd_label_data_init+0x10e/0x800 [libnvdimm] Code and flow: 1) CXL Command 4000h returns LSA size = 0 2) config_size is assigned to zero LSA size (CXL pmem driver): drivers/cxl/pmem.c: .config_size = mds->lsa_size, 3) max_xfer is set to zero (nvdimm driver): drivers/nvdimm/label.c: max_xfer = min_t(size_t, ndd->nsarea.max_xfer, config_size); 4) A subsequent DIV_ROUND_UP() causes a division by zero: drivers/nvdimm/label.c: /* Make our initial read size a multiple of max_xfer size */ drivers/nvdimm/label.c: read_size = min(DIV_ROUND_UP(read_size, max_xfer) * max_xfer, drivers/nvdimm/label.c- config_size); Fix this by checking the config size parameter by extending an existing check. Signed-off-by: Robert Richter <rrichter@amd.com> Reviewed-by: Pankaj Gupta <pankaj.gupta@amd.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Link: https://patch.msgid.link/20250320112223.608320-1-rrichter@amd.com Signed-off-by: Ira Weiny <ira.weiny@intel.com>
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do_alignment_t32_to_handler() only fixes up alignment faults for
specific instructions; it returns NULL otherwise (e.g. LDREX). When
that's the case, signal to the caller that it needs to proceed with the
regular alignment fault handling (i.e. SIGBUS). Without this patch, the
kernel panics:
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
Mem abort info:
ESR = 0x0000000086000006
EC = 0x21: IABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x06: level 2 translation fault
user pgtable: 4k pages, 48-bit VAs, pgdp=00000800164aa000
[0000000000000000] pgd=0800081fdbd22003, p4d=0800081fdbd22003, pud=08000815d51c6003, pmd=0000000000000000
Internal error: Oops: 0000000086000006 [#1] SMP
Modules linked in: cfg80211 rfkill xt_nat xt_tcpudp xt_conntrack nft_chain_nat xt_MASQUERADE nf_nat nf_conntrack_netlink nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 xfrm_user xfrm_algo xt_addrtype nft_compat br_netfilter veth nvme_fa>
libcrc32c crc32c_generic raid0 multipath linear dm_mod dax raid1 md_mod xhci_pci nvme xhci_hcd nvme_core t10_pi usbcore igb crc64_rocksoft crc64 crc_t10dif crct10dif_generic crct10dif_ce crct10dif_common usb_common i2c_algo_bit i2c>
CPU: 2 PID: 3932954 Comm: WPEWebProcess Not tainted 6.1.0-31-arm64 #1 Debian 6.1.128-1
Hardware name: GIGABYTE MP32-AR1-00/MP32-AR1-00, BIOS F18v (SCP: 1.08.20211002) 12/01/2021
pstate: 80400009 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : 0x0
lr : do_compat_alignment_fixup+0xd8/0x3dc
sp : ffff80000f973dd0
x29: ffff80000f973dd0 x28: ffff081b42526180 x27: 0000000000000000
x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000000
x23: 0000000000000004 x22: 0000000000000000 x21: 0000000000000001
x20: 00000000e8551f00 x19: ffff80000f973eb0 x18: 0000000000000000
x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000
x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000
x11: 0000000000000000 x10: 0000000000000000 x9 : ffffaebc949bc488
x8 : 0000000000000000 x7 : 0000000000000000 x6 : 0000000000000000
x5 : 0000000000400000 x4 : 0000fffffffffffe x3 : 0000000000000000
x2 : ffff80000f973eb0 x1 : 00000000e8551f00 x0 : 0000000000000001
Call trace:
0x0
do_alignment_fault+0x40/0x50
do_mem_abort+0x4c/0xa0
el0_da+0x48/0xf0
el0t_32_sync_handler+0x110/0x140
el0t_32_sync+0x190/0x194
Code: bad PC value
---[ end trace 0000000000000000 ]---
Signed-off-by: Angelos Oikonomopoulos <angelos@igalia.com>
Fixes: 3fc24ef ("arm64: compat: Implement misalignment fixups for multiword loads")
Cc: <stable@vger.kernel.org> # 6.1.x
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Link: https://lore.kernel.org/r/20250401085150.148313-1-angelos@igalia.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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I found a NULL pointer dereference as followed: BUG: kernel NULL pointer dereference, address: 0000000000000028 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: Oops: 0000 [#1] SMP PTI CPU: 5 UID: 0 PID: 5964 Comm: sh Kdump: loaded Not tainted 6.13.0-dirty torvalds#20 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1. RIP: 0010:has_unmovable_pages+0x184/0x360 ... Call Trace: <TASK> set_migratetype_isolate+0xd1/0x180 start_isolate_page_range+0xd2/0x170 alloc_contig_range_noprof+0x101/0x660 alloc_contig_pages_noprof+0x238/0x290 alloc_gigantic_folio.isra.0+0xb6/0x1f0 only_alloc_fresh_hugetlb_folio.isra.0+0xf/0x60 alloc_pool_huge_folio+0x80/0xf0 set_max_huge_pages+0x211/0x490 __nr_hugepages_store_common+0x5f/0xe0 nr_hugepages_store+0x77/0x80 kernfs_fop_write_iter+0x118/0x200 vfs_write+0x23c/0x3f0 ksys_write+0x62/0xe0 do_syscall_64+0x5b/0x170 entry_SYSCALL_64_after_hwframe+0x76/0x7e As has_unmovable_pages() call folio_hstate() without hugetlb_lock, there is a race to free the HugeTLB page between PageHuge() and folio_hstate(). There is no need to add hugetlb_lock here as the HugeTLB page can be freed in lot of places. So it's enough to unfold folio_hstate() and add a check to avoid NULL pointer dereference for hugepage_migration_supported(). Link: https://lkml.kernel.org/r/20250122061151.578768-1-liushixin2@huawei.com Fixes: 464c7ff ("mm/hugetlb: filter out hugetlb pages if HUGEPAGE migration is not supported.") Signed-off-by: Liu Shixin <liushixin2@huawei.com> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Kirill A. Shuemov <kirill.shutemov@linux.intel.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nanyong Sun <sunnanyong@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Currently, zswap_cpu_comp_dead() calls crypto_free_acomp() while holding the per-CPU acomp_ctx mutex. crypto_free_acomp() then holds scomp_lock (through crypto_exit_scomp_ops_async()). On the other hand, crypto_alloc_acomp_node() holds the scomp_lock (through crypto_scomp_init_tfm()), and then allocates memory. If the allocation results in reclaim, we may attempt to hold the per-CPU acomp_ctx mutex. The above dependencies can cause an ABBA deadlock. For example in the following scenario: (1) Task A running on CPU #1: crypto_alloc_acomp_node() Holds scomp_lock Enters reclaim Reads per_cpu_ptr(pool->acomp_ctx, 1) (2) Task A is descheduled (3) CPU #1 goes offline zswap_cpu_comp_dead(CPU #1) Holds per_cpu_ptr(pool->acomp_ctx, 1)) Calls crypto_free_acomp() Waits for scomp_lock (4) Task A running on CPU #2: Waits for per_cpu_ptr(pool->acomp_ctx, 1) // Read on CPU #1 DEADLOCK Since there is no requirement to call crypto_free_acomp() with the per-CPU acomp_ctx mutex held in zswap_cpu_comp_dead(), move it after the mutex is unlocked. Also move the acomp_request_free() and kfree() calls for consistency and to avoid any potential sublte locking dependencies in the future. With this, only setting acomp_ctx fields to NULL occurs with the mutex held. This is similar to how zswap_cpu_comp_prepare() only initializes acomp_ctx fields with the mutex held, after performing all allocations before holding the mutex. Opportunistically, move the NULL check on acomp_ctx so that it takes place before the mutex dereference. Link: https://lkml.kernel.org/r/20250226185625.2672936-1-yosry.ahmed@linux.dev Fixes: 12dcb0e ("mm: zswap: properly synchronize freeing resources during CPU hotunplug") Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Co-developed-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Yosry Ahmed <yosry.ahmed@linux.dev> Reported-by: syzbot+1a517ccfcbc6a7ab0f82@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/67bcea51.050a0220.bbfd1.0096.GAE@google.com/ Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev> Reviewed-by: Nhat Pham <nphamcs@gmail.com> Tested-by: Nhat Pham <nphamcs@gmail.com> Cc: David S. Miller <davem@davemloft.net> Cc: Eric Biggers <ebiggers@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Chris Murphy <lists@colorremedies.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Patch series "mm: fixes for fallouts from mem_init() cleanup". These are the fixes for fallouts from mem_init() cleanup reported by Nathan Chancellor and kbuild. The details are in the commit messages. This patch (of 2): Kernel test robot reports the following crash on 32-bit system with FLATMEM and DEBUG_VM_PGFLAGS enabled: [ 0.478822][ T0] kernel BUG at include/linux/page-flags.h:536! [ 0.479312][ T0] Oops: invalid opcode: 0000 [#1] PREEMPT SMP [ 0.479768][ T0] CPU: 0 UID: 0 PID: 0 Comm: swapper Not tainted 6.14.0-rc6-00357-g8268af309d07 #1 [ 0.480470][ T0] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 [ 0.481260][ T0] EIP: reserve_bootmem_region (include/linux/page-flags.h:536) [ 0.481683][ T0] Code: 5d c3 01 f1 89 c8 ba e1 38 f4 c3 e8 1e 37 8e fc 0f 0b b8 90 e2 62 c4 e8 e2 05 5e fc 01 f1 89 c8 ba be 85 f7 c3 e8 04 37 8e fc <0f> 0b b8 80 e2 62 c4 e8 c8 05 5e fc 55 89 e5 53 57 56 83 ec 10 89 [ 0.483177][ T0] EAX: 00000000 EBX: c425df50 ECX: 00000000 EDX: 00000000 [ 0.483712][ T0] ESI: 017ffc00 EDI: ffffffff EBP: c425df34 ESP: c425df2c [ 0.484248][ T0] DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 EFLAGS: 00210046 [ 0.484846][ T0] CR0: 80050033 CR2: 00000000 CR3: 04b48000 CR4: 00000090 [ 0.485376][ T0] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000 [ 0.485907][ T0] DR6: fffe0ff0 DR7: 00000400 [ 0.486253][ T0] Call Trace: [ 0.486494][ T0] ? __die_body (arch/x86/kernel/dumpstack.c:478) [ 0.486822][ T0] ? die (arch/x86/kernel/dumpstack.c:?) [ 0.487099][ T0] ? do_trap (arch/x86/kernel/traps.c:? arch/x86/kernel/traps.c:197) [ 0.487409][ T0] ? do_error_trap (arch/x86/kernel/traps.c:217) [ 0.487752][ T0] ? reserve_bootmem_region (include/linux/page-flags.h:536) [ 0.488153][ T0] ? exc_overflow (arch/x86/kernel/traps.c:301) [ 0.488490][ T0] ? handle_invalid_op (arch/x86/kernel/traps.c:254) [ 0.488869][ T0] ? reserve_bootmem_region (include/linux/page-flags.h:536) [ 0.489271][ T0] ? exc_invalid_op (arch/x86/kernel/traps.c:316) [ 0.489619][ T0] ? handle_exception (arch/x86/entry/entry_32.S:1055) [ 0.489996][ T0] ? exc_overflow (arch/x86/kernel/traps.c:301) [ 0.490332][ T0] ? reserve_bootmem_region (include/linux/page-flags.h:536) [ 0.490733][ T0] ? exc_overflow (arch/x86/kernel/traps.c:301) [ 0.491068][ T0] ? reserve_bootmem_region (include/linux/page-flags.h:536) [ 0.491470][ T0] memmap_init_reserved_pages (mm/memblock.c:2203) [ 0.491887][ T0] free_low_memory_core_early (mm/memblock.c:?) [ 0.492302][ T0] memblock_free_all (mm/memblock.c:2272 include/linux/atomic/atomic-arch-fallback.h:546 include/linux/atomic/atomic-long.h:123 include/linux/atomic/atomic-instrumented.h:3261 include/linux/mm.h:67 mm/memblock.c:2273) [ 0.492659][ T0] mem_init (arch/x86/mm/init_32.c:735) [ 0.492952][ T0] mm_core_init (mm/mm_init.c:2730) [ 0.493271][ T0] start_kernel (init/main.c:958) [ 0.493604][ T0] i386_start_kernel (arch/x86/kernel/head32.c:79) [ 0.493969][ T0] startup_32_smp (arch/x86/kernel/head_32.S:292) The crash happens because after commit 8268af3 ("arch, mm: set max_mapnr when allocating memory map for FLATMEM") max_mapnr is rounded up to MAX_ORDER_NR_PAGES and the pages in the end of the memory map are passing pfn_valid() check in reserve_bootmem_region(). Make sure that that pages in the end of the memory map are initialized, just like the pages in the end of the last section for SPARSEMEM. Link: https://lkml.kernel.org/r/20250325114928.1791109-1-rppt@kernel.org Link: https://lkml.kernel.org/r/20250325114928.1791109-2-rppt@kernel.org Fixes: 8268af3 ("arch, mm: set max_mapnr when allocating memory map for FLATMEM") Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Reported-by: kernel test robot <oliver.sang@intel.com> Closes: https://lore.kernel.org/oe-lkp/202503241424.d16223ec-lkp@intel.com Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Betkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleinxer <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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… off Nathan Chancellor reports the following crash on a MIPS system with CONFIG_HIGHMEM=n: Linux version 6.14.0-rc6-00359-g6faea3422e3b (nathan@ax162) (mips-linux-gcc (GCC) 14.2.0, GNU ld (GNU Binutils) 2.42) #1 SMP Fri Mar 21 08:12:02 MST 2025 earlycon: uart8250 at I/O port 0x3f8 (options '38400n8') printk: legacy bootconsole [uart8250] enabled Config serial console: console=ttyS0,38400n8r CPU0 revision is: 00019300 (MIPS 24Kc) FPU revision is: 00739300 MIPS: machine is mti,malta Software DMA cache coherency enabled Initial ramdisk at: 0x8fad0000 (5360128 bytes) OF: reserved mem: Reserved memory: No reserved-memory node in the DT Primary instruction cache 2kB, VIPT, 2-way, linesize 16 bytes. Primary data cache 2kB, 2-way, VIPT, no aliases, linesize 16 bytes Zone ranges: DMA [mem 0x0000000000000000-0x0000000000ffffff] Normal [mem 0x0000000001000000-0x000000001fffffff] Movable zone start for each node Early memory node ranges node 0: [mem 0x0000000000000000-0x000000000fffffff] node 0: [mem 0x0000000090000000-0x000000009fffffff] Initmem setup node 0 [mem 0x0000000000000000-0x000000009fffffff] On node 0, zone Normal: 16384 pages in unavailable ranges random: crng init done percpu: Embedded 3 pages/cpu s18832 r8192 d22128 u49152 Kernel command line: rd_start=0xffffffff8fad0000 rd_size=5360128 console=ttyS0,38400n8r printk: log buffer data + meta data: 32768 + 102400 = 135168 bytes Dentry cache hash table entries: 65536 (order: 4, 262144 bytes, linear) Inode-cache hash table entries: 32768 (order: 3, 131072 bytes, linear) Writing ErrCtl register=00000000 Readback ErrCtl register=00000000 Built 1 zonelists, mobility grouping on. Total pages: 16384 mem auto-init: stack:all(zero), heap alloc:off, heap free:off Unhandled kernel unaligned access[#1]: CPU: 0 UID: 0 PID: 0 Comm: swapper Not tainted 6.14.0-rc6-00359-g6faea3422e3b #1 Hardware name: mti,malta $ 0 : 00000000 00000001 81cb0880 00129027 $ 4 : 00000001 0000000a 00000002 00129026 $ 8 : ffffdfff 80101e00 00000002 00000000 $12 : 81c9c224 81c63e68 00000002 00000000 $16 : 805b1e00 00025800 81cb0880 00000002 $20 : 00000000 81c63e6 0000000a 81f10000 $24 : 81c63e6 81c63e60 $28 : 81c60000 81c63de0 00000001 81cc9d20 Hi : 00000000 Lo : 00000000 epc : 814a227c __free_pages_ok+0x144/0x3c0 ra : 81cc9d20 memblock_free_all+0x1d4/0x27c Status: 10000002 KERNEL EXL Cause : 00800410 (ExcCode 04) BadVA : 00129026 PrId : 00019300 (MIPS 24Kc) Modules linked in: Process swapper (pid: 0, threadinfo=(ptrval), task=(ptrval), tls=00000000) Stack : 81f10000 805a9e00 81c80000 00000000 00000002 814aa240 000003ff 00000400 00000000 81f10000 81c9c224 00003b1f 81c80000 81c63e60 81ca0000 81c63e6 81f10000 0000000a 0000001f 81cc9d20 81f10000 81cc96d8 00000000 81c80000 81c9c224 81c63e60 81c63e6 00000000 81f10000 00024000 00028000 00025c00 90000000 a0000000 00000002 00000017 00000000 00000000 81f10000 81f10000 ... Call Trace: [<814a227c>] __free_pages_ok+0x144/0x3c0 [<81cc9d20>] memblock_free_all+0x1d4/0x27c [<81cc6764>] mm_core_init+0x100/0x138 [<81cb4ba4>] start_kernel+0x4a0/0x6e4 Code: 1080ffd5 02003825 2467ffff <8ce30000> 7c630500 1060ffd4 00000000 8ce30000 7c630180 The crash happens because commit 6faea34 ("arch, mm: streamline HIGHMEM freeing") too eagerly frees high memory to the page allocator even when HIGHMEM is disabled. Make sure that when CONFIG_HIGHMEM=n the high memory is not released to the page allocator. Link: https://lore.kernel.org/all/20250323190647.GA1009914@ax162 Link: https://lkml.kernel.org/r/20250325114928.1791109-3-rppt@kernel.org Reported-by: Nathan Chancellor <nathan@kernel.org> Fixes: 6faea34 ("arch, mm: streamline HIGHMEM freeing") Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Tested-by: Nathan Chancellor <nathan@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Betkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleinxer <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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…rate_range We triggered the below BUG: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x2 pfn:0x240402 head: order:9 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x1ffffe0000000040(head|node=1|zone=3|lastcpupid=0x1ffff) page_type: f4(hugetlb) page dumped because: VM_BUG_ON_PAGE(page->compound_head & 1) ------------[ cut here ]------------ kernel BUG at ./include/linux/page-flags.h:310! Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP Modules linked in: CPU: 7 UID: 0 PID: 166 Comm: sh Not tainted 6.14.0-rc7-dirty torvalds#374 Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015 pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : const_folio_flags+0x3c/0x58 lr : const_folio_flags+0x3c/0x58 Call trace: const_folio_flags+0x3c/0x58 (P) do_migrate_range+0x164/0x720 offline_pages+0x63c/0x6fc memory_subsys_offline+0x190/0x1f4 device_offline+0xc0/0x13c state_store+0x90/0xd8 dev_attr_store+0x18/0x2c sysfs_kf_write+0x44/0x54 kernfs_fop_write_iter+0x120/0x1cc vfs_write+0x240/0x378 ksys_write+0x70/0x108 __arm64_sys_write+0x1c/0x28 invoke_syscall+0x48/0x10c el0_svc_common.constprop.0+0x40/0xe0 When allocating a hugetlb folio, between the folio is taken from buddy and prep_compound_page() is called, start_isolate_page_range() and do_migrate_range() is called. When do_migrate_range() scans the head page of the hugetlb folio, the compound_head field isn't set, so scans the tail page next. And at this time, the compound_head field of tail page is set, folio_test_large() is called by tail page, thus triggers VM_BUG_ON(). To fix it, get folio refcount before calling folio_test_large(). Link: https://lkml.kernel.org/r/20250324131750.1551884-1-tujinjiang@huawei.com Fixes: 8135d89 ("mm: memory_hotplug: memory hotremove supports thp migration") Fixes: b62b51d ("mm: memory_hotplug: remove head variable in do_migrate_range()") Signed-off-by: Jinjiang Tu <tujinjiang@huawei.com> Acked-by: Oscar Salvador <osalvador@suse.de> Acked-by: David Hildenbrand <david@redhat.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Nanyong Sun <sunnanyong@huawei.com> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
akiyks
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Two fixes from the recent logging changes:
bch2_inconsistent(), bch2_fs_inconsistent() be called from interrupt
context, or with rcu_read_lock() held.
The one syzbot found is in
bch2_bkey_pick_read_device
bch2_dev_rcu
bch2_fs_inconsistent
We're starting to switch to lift the printbufs up to higher levels so we
can emit better log messages and print them all in one go (avoid
garbling), so that conversion will help with spotting these in the
future; when we declare a printbuf it must be flagged if we're in an
atomic context.
Secondly, in btree_node_write_endio:
00085 BUG: sleeping function called from invalid context at include/linux/sched/mm.h:321
00085 in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 618, name: bch-reclaim/fa6
00085 preempt_count: 10001, expected: 0
00085 RCU nest depth: 0, expected: 0
00085 4 locks held by bch-reclaim/fa6/618:
00085 #0: ffffff80d7ccad68 (&j->reclaim_lock){+.+.}-{4:4}, at: bch2_journal_reclaim_thread+0x84/0x198
00085 #1: ffffff80d7c84218 (&c->btree_trans_barrier){.+.+}-{0:0}, at: __bch2_trans_get+0x1c0/0x440
00085 #2: ffffff80cd3f8140 (bcachefs_btree){+.+.}-{0:0}, at: __bch2_trans_get+0x22c/0x440
00085 #3: ffffff80c3823c20 (&vblk->vqs[i].lock){-.-.}-{3:3}, at: virtblk_done+0x58/0x130
00085 irq event stamp: 328
00085 hardirqs last enabled at (327): [<ffffffc080073a14>] finish_task_switch.isra.0+0xbc/0x2a0
00085 hardirqs last disabled at (328): [<ffffffc080971a10>] el1_interrupt+0x20/0x60
00085 softirqs last enabled at (0): [<ffffffc08002f920>] copy_process+0x7c8/0x2118
00085 softirqs last disabled at (0): [<0000000000000000>] 0x0
00085 Preemption disabled at:
00085 [<ffffffc08003ada0>] irq_enter_rcu+0x18/0x90
00085 CPU: 8 UID: 0 PID: 618 Comm: bch-reclaim/fa6 Not tainted 6.14.0-rc6-ktest-g04630bde23e8 #18798
00085 Hardware name: linux,dummy-virt (DT)
00085 Call trace:
00085 show_stack+0x1c/0x30 (C)
00085 dump_stack_lvl+0x84/0xc0
00085 dump_stack+0x14/0x20
00085 __might_resched+0x180/0x288
00085 __might_sleep+0x4c/0x88
00085 __kmalloc_node_track_caller_noprof+0x34c/0x3e0
00085 krealloc_noprof+0x1a0/0x2d8
00085 bch2_printbuf_make_room+0x9c/0x120
00085 bch2_prt_printf+0x60/0x1b8
00085 btree_node_write_endio+0x1b0/0x2d8
00085 bio_endio+0x138/0x1f0
00085 btree_node_write_endio+0xe8/0x2d8
00085 bio_endio+0x138/0x1f0
00085 blk_update_request+0x220/0x4c0
00085 blk_mq_end_request+0x28/0x148
00085 virtblk_request_done+0x64/0xe8
00085 blk_mq_complete_request+0x34/0x40
00085 virtblk_done+0x78/0x130
00085 vring_interrupt+0x6c/0xb0
00085 __handle_irq_event_percpu+0x8c/0x2e0
00085 handle_irq_event+0x50/0xb0
00085 handle_fasteoi_irq+0xc4/0x250
00085 handle_irq_desc+0x44/0x60
00085 generic_handle_domain_irq+0x20/0x30
00085 gic_handle_irq+0x54/0xc8
00085 call_on_irq_stack+0x24/0x40
Reported-by: syzbot+c82cd2906e2f192410bb@syzkaller.appspotmail.com
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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@tgkz @KosukeFujimoto
SubmittingPatches の日本語訳の中で、意味不明な訳語の一つについての相談を
この issue で試してみます。
"Developer's certificate of origin" が「原作者の証明書」と訳されていますが、
"certificate of authorship" という意味にも解釈できてしまいます。
「開発者の源泉証明書」とすると、日本の場合は税金の「源泉徴収」の悪影響で
意味不明になってしまいます。
ちなみに、簡体中国語訳では「开发者来源证书」と訳されています。
ソースコードの「出どころ」の証明書の意味で使える origin の訳語が欲しいのです。
「出所」 「出所」 「由来」 「源流」 など、どれもしっくりしないですね。
DCO は LF が作ったものですが、これの定訳はあるのでしょうか？
単に "certificate of origin" の和訳を調べると、輸出入の「原産地証明書」になってしまい、
使えません。
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