slub: Add method to verify memory is not freed

This is for tracking down suspect memory usage.

Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
This commit is contained in:
Ben Greear 2011-07-07 11:36:37 -07:00 committed by Pekka Enberg
parent d6543e3935
commit d18a90dd85
2 changed files with 49 additions and 0 deletions

View File

@ -218,6 +218,19 @@ kmalloc_order(size_t size, gfp_t flags, unsigned int order)
return ret;
}
/**
* Calling this on allocated memory will check that the memory
* is expected to be in use, and print warnings if not.
*/
#ifdef CONFIG_SLUB_DEBUG
extern bool verify_mem_not_deleted(const void *x);
#else
static inline bool verify_mem_not_deleted(const void *x)
{
return true;
}
#endif
#ifdef CONFIG_TRACING
extern void *
kmem_cache_alloc_trace(struct kmem_cache *s, gfp_t gfpflags, size_t size);

View File

@ -2964,6 +2964,42 @@ size_t ksize(const void *object)
}
EXPORT_SYMBOL(ksize);
#ifdef CONFIG_SLUB_DEBUG
bool verify_mem_not_deleted(const void *x)
{
struct page *page;
void *object = (void *)x;
unsigned long flags;
bool rv;
if (unlikely(ZERO_OR_NULL_PTR(x)))
return false;
local_irq_save(flags);
page = virt_to_head_page(x);
if (unlikely(!PageSlab(page))) {
/* maybe it was from stack? */
rv = true;
goto out_unlock;
}
slab_lock(page);
if (on_freelist(page->slab, page, object)) {
object_err(page->slab, page, object, "Object is on free-list");
rv = false;
} else {
rv = true;
}
slab_unlock(page);
out_unlock:
local_irq_restore(flags);
return rv;
}
EXPORT_SYMBOL(verify_mem_not_deleted);
#endif
void kfree(const void *x)
{
struct page *page;