diff options
author | Catalin Marinas <catalin.marinas@arm.com> | 2011-09-26 18:12:53 +0200 |
---|---|---|
committer | Catalin Marinas <catalin.marinas@arm.com> | 2011-12-02 17:12:42 +0100 |
commit | f528f0b8e53d73b18be71e96693cfab9322f33c7 (patch) | |
tree | 5a25d6ac1c2f18561e554074aa7c06bf3d899183 /mm/kmemleak.c | |
parent | kmemleak: Report previously found leaks even after an error (diff) | |
download | linux-f528f0b8e53d73b18be71e96693cfab9322f33c7.tar.xz linux-f528f0b8e53d73b18be71e96693cfab9322f33c7.zip |
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>
Diffstat (limited to 'mm/kmemleak.c')
-rw-r--r-- | mm/kmemleak.c | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/mm/kmemleak.c b/mm/kmemleak.c index b4f4e6021c1b..15c50302ff93 100644 --- a/mm/kmemleak.c +++ b/mm/kmemleak.c @@ -230,8 +230,10 @@ static int kmemleak_skip_disable; /* kmemleak operation type for early logging */ enum { KMEMLEAK_ALLOC, + KMEMLEAK_ALLOC_PERCPU, KMEMLEAK_FREE, KMEMLEAK_FREE_PART, + KMEMLEAK_FREE_PERCPU, KMEMLEAK_NOT_LEAK, KMEMLEAK_IGNORE, KMEMLEAK_SCAN_AREA, @@ -852,6 +854,20 @@ out: rcu_read_unlock(); } +/* + * Log an early allocated block and populate the stack trace. + */ +static void early_alloc_percpu(struct early_log *log) +{ + unsigned int cpu; + const void __percpu *ptr = log->ptr; + + for_each_possible_cpu(cpu) { + log->ptr = per_cpu_ptr(ptr, cpu); + early_alloc(log); + } +} + /** * kmemleak_alloc - register a newly allocated object * @ptr: pointer to beginning of the object @@ -879,6 +895,34 @@ void __ref kmemleak_alloc(const void *ptr, size_t size, int min_count, EXPORT_SYMBOL_GPL(kmemleak_alloc); /** + * kmemleak_alloc_percpu - register a newly allocated __percpu object + * @ptr: __percpu pointer to beginning of the object + * @size: size of the object + * + * This function is called from the kernel percpu allocator when a new object + * (memory block) is allocated (alloc_percpu). It assumes GFP_KERNEL + * allocation. + */ +void __ref kmemleak_alloc_percpu(const void __percpu *ptr, size_t size) +{ + unsigned int cpu; + + pr_debug("%s(0x%p, %zu)\n", __func__, ptr, size); + + /* + * Percpu allocations are only scanned and not reported as leaks + * (min_count is set to 0). + */ + if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr)) + for_each_possible_cpu(cpu) + create_object((unsigned long)per_cpu_ptr(ptr, cpu), + size, 0, GFP_KERNEL); + else if (atomic_read(&kmemleak_early_log)) + log_early(KMEMLEAK_ALLOC_PERCPU, ptr, size, 0); +} +EXPORT_SYMBOL_GPL(kmemleak_alloc_percpu); + +/** * kmemleak_free - unregister a previously registered object * @ptr: pointer to beginning of the object * @@ -917,6 +961,28 @@ void __ref kmemleak_free_part(const void *ptr, size_t size) EXPORT_SYMBOL_GPL(kmemleak_free_part); /** + * kmemleak_free_percpu - unregister a previously registered __percpu object + * @ptr: __percpu pointer to beginning of the object + * + * This function is called from the kernel percpu allocator when an object + * (memory block) is freed (free_percpu). + */ +void __ref kmemleak_free_percpu(const void __percpu *ptr) +{ + unsigned int cpu; + + pr_debug("%s(0x%p)\n", __func__, ptr); + + if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr)) + for_each_possible_cpu(cpu) + delete_object_full((unsigned long)per_cpu_ptr(ptr, + cpu)); + else if (atomic_read(&kmemleak_early_log)) + log_early(KMEMLEAK_FREE_PERCPU, ptr, 0, 0); +} +EXPORT_SYMBOL_GPL(kmemleak_free_percpu); + +/** * kmemleak_not_leak - mark an allocated object as false positive * @ptr: pointer to beginning of the object * @@ -1727,12 +1793,18 @@ void __init kmemleak_init(void) case KMEMLEAK_ALLOC: early_alloc(log); break; + case KMEMLEAK_ALLOC_PERCPU: + early_alloc_percpu(log); + break; case KMEMLEAK_FREE: kmemleak_free(log->ptr); break; case KMEMLEAK_FREE_PART: kmemleak_free_part(log->ptr, log->size); break; + case KMEMLEAK_FREE_PERCPU: + kmemleak_free_percpu(log->ptr); + break; case KMEMLEAK_NOT_LEAK: kmemleak_not_leak(log->ptr); break; |