percpu: clear memory allocated with the km allocator

htejun · htejun · commit fc1481a95618 · 2010-09-10T10:56:24.000+02:00
Percpu allocator should clear memory before returning it but the km
allocator forgot to do it.  Fix it.

Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Reported-by: Peter Zijlstra &lt;peterz@infradead.org&gt;
Acked-by: Peter Zijlstra &lt;peterz@infradead.org&gt;
diff --git a/mm/percpu-km.c b/mm/percpu-km.c
@@ -35,7 +35,11 @@
 
 static int pcpu_populate_chunk(struct pcpu_chunk *chunk, int off, int size)
 {
-	/* noop */
+	unsigned int cpu;
+
+	for_each_possible_cpu(cpu)
+		memset((void *)pcpu_chunk_addr(chunk, cpu, 0) + off, 0, size);
+
 	return 0;
 }
 

Original file line number	Diff line number	Diff line change
`@@ -35,7 +35,11 @@`
`35`	`35`
`36`	`36`	`static int pcpu_populate_chunk(struct pcpu_chunk *chunk, int off, int size)`
`37`	`37`	`{`
`38`		`- /* noop */`
	`38`	`+ unsigned int cpu;`
	`39`	`+`
	`40`	`+ for_each_possible_cpu(cpu)`
	`41`	`+ memset((void *)pcpu_chunk_addr(chunk, cpu, 0) + off, 0, size);`
	`42`	`+`
`39`	`43`	`return 0;`
`40`	`44`	`}`
`41`	`45`