From 8ff6d8903672a670cc8067ec020e2a533835b181 Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Sat, 17 May 2014 23:19:27 +1000 Subject: [PATCH] mm: introduce kmemleak_update_trace() The memory allocation stack trace is not always useful for debugging a memory leak (e.g. radix_tree_preload). This function, when called, updates the stack trace for an already allocated object. Signed-off-by: Catalin Marinas Cc: Johannes Weiner Signed-off-by: Andrew Morton --- Documentation/kmemleak.txt | 1 + include/linux/kmemleak.h | 4 ++++ mm/kmemleak.c | 34 ++++++++++++++++++++++++++++++++++ 3 files changed, 39 insertions(+) diff --git a/Documentation/kmemleak.txt b/Documentation/kmemleak.txt index a7563ec4ea7b..b772418bf064 100644 --- a/Documentation/kmemleak.txt +++ b/Documentation/kmemleak.txt @@ -142,6 +142,7 @@ kmemleak_alloc_percpu - notify of a percpu memory block allocation kmemleak_free - notify of a memory block freeing kmemleak_free_part - notify of a partial memory block freeing kmemleak_free_percpu - notify of a percpu memory block freeing +kmemleak_update_trace - update object allocation stack trace kmemleak_not_leak - mark an object as not a leak kmemleak_ignore - do not scan or report an object as leak kmemleak_scan_area - add scan areas inside a memory block diff --git a/include/linux/kmemleak.h b/include/linux/kmemleak.h index 5bb424659c04..057e95971014 100644 --- a/include/linux/kmemleak.h +++ b/include/linux/kmemleak.h @@ -30,6 +30,7 @@ extern void kmemleak_alloc_percpu(const void __percpu *ptr, size_t size) __ref; extern void kmemleak_free(const void *ptr) __ref; extern void kmemleak_free_part(const void *ptr, size_t size) __ref; extern void kmemleak_free_percpu(const void __percpu *ptr) __ref; +extern void kmemleak_update_trace(const void *ptr) __ref; extern void kmemleak_not_leak(const void *ptr) __ref; extern void kmemleak_ignore(const void *ptr) __ref; extern void kmemleak_scan_area(const void *ptr, size_t size, gfp_t gfp) __ref; @@ -83,6 +84,9 @@ static inline void kmemleak_free_recursive(const void *ptr, unsigned long flags) static inline void kmemleak_free_percpu(const void __percpu *ptr) { } +static inline void kmemleak_update_trace(const void *ptr) +{ +} static inline void kmemleak_not_leak(const void *ptr) { } diff --git a/mm/kmemleak.c b/mm/kmemleak.c index 5d4aec44982e..3cda50c1e394 100644 --- a/mm/kmemleak.c +++ b/mm/kmemleak.c @@ -989,6 +989,40 @@ void __ref kmemleak_free_percpu(const void __percpu *ptr) } EXPORT_SYMBOL_GPL(kmemleak_free_percpu); +/** + * kmemleak_update_trace - update object allocation stack trace + * @ptr: pointer to beginning of the object + * + * Override the object allocation stack trace for cases where the actual + * allocation place is not always useful. + */ +void __ref kmemleak_update_trace(const void *ptr) +{ + struct kmemleak_object *object; + unsigned long flags; + + pr_debug("%s(0x%p)\n", __func__, ptr); + + if (!kmemleak_enabled || IS_ERR_OR_NULL(ptr)) + return; + + object = find_and_get_object((unsigned long)ptr, 1); + if (!object) { +#ifdef DEBUG + kmemleak_warn("Updating stack trace for unknown object at %p\n", + ptr); +#endif + return; + } + + spin_lock_irqsave(&object->lock, flags); + object->trace_len = __save_stack_trace(object->trace); + spin_unlock_irqrestore(&object->lock, flags); + + put_object(object); +} +EXPORT_SYMBOL(kmemleak_update_trace); + /** * kmemleak_not_leak - mark an allocated object as false positive * @ptr: pointer to beginning of the object -- 2.39.5