kmemleak: Handle percpu memory allocation
This patch adds kmemleak callbacks from the percpu allocator, reducing a
number of false positives caused by kmemleak not scanning such memory
blocks. The percpu chunks are never reported as leaks because of current
kmemleak limitations with the __percpu pointer not pointing directly to
the actual chunks.
Reported-by: Huajun Li <huajun.li.lee@gmail.com>
Acked-by: Christoph Lameter <cl@gentwo.org>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
diff --git a/mm/percpu.c b/mm/percpu.c
index 3bb810a..86c5bdb 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -67,6 +67,7 @@
#include <linux/spinlock.h>
#include <linux/vmalloc.h>
#include <linux/workqueue.h>
+#include <linux/kmemleak.h>
#include <asm/cacheflush.h>
#include <asm/sections.h>
@@ -710,6 +711,7 @@
const char *err;
int slot, off, new_alloc;
unsigned long flags;
+ void __percpu *ptr;
if (unlikely(!size || size > PCPU_MIN_UNIT_SIZE || align > PAGE_SIZE)) {
WARN(true, "illegal size (%zu) or align (%zu) for "
@@ -802,7 +804,9 @@
mutex_unlock(&pcpu_alloc_mutex);
/* return address relative to base address */
- return __addr_to_pcpu_ptr(chunk->base_addr + off);
+ ptr = __addr_to_pcpu_ptr(chunk->base_addr + off);
+ kmemleak_alloc_percpu(ptr, size);
+ return ptr;
fail_unlock:
spin_unlock_irqrestore(&pcpu_lock, flags);
@@ -916,6 +920,8 @@
if (!ptr)
return;
+ kmemleak_free_percpu(ptr);
+
addr = __pcpu_ptr_to_addr(ptr);
spin_lock_irqsave(&pcpu_lock, flags);
@@ -1637,6 +1643,8 @@
rc = -ENOMEM;
goto out_free_areas;
}
+ /* kmemleak tracks the percpu allocations separately */
+ kmemleak_free(ptr);
areas[group] = ptr;
base = min(ptr, base);
@@ -1751,6 +1759,8 @@
"for cpu%u\n", psize_str, cpu);
goto enomem;
}
+ /* kmemleak tracks the percpu allocations separately */
+ kmemleak_free(ptr);
pages[j++] = virt_to_page(ptr);
}