From e7cb55b946a2182c347047dc903c6ed0daef100c Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Wed, 28 Oct 2009 13:33:08 +0000 Subject: kmemleak: Do not use off-slab management with SLAB_NOLEAKTRACE With the slab allocator, if off-slab management is enabled for the kmem_caches used by kmemleak, it leads to recursive calls into kmemleak_alloc(). Off-slab management can be triggered by other config options increasing the slab size, e.g. DEBUG_PAGEALLOC. Reported-by: Tetsuo Handa Reviewed-by: Pekka Enberg Cc: Christoph Lameter Signed-off-by: Catalin Marinas --- mm/slab.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'mm/slab.c') diff --git a/mm/slab.c b/mm/slab.c index 7dfa481c96ba..646db3085193 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -2261,9 +2261,11 @@ kmem_cache_create (const char *name, size_t size, size_t align, /* * Determine if the slab management is 'on' or 'off' slab. * (bootstrapping cannot cope with offslab caches so don't do - * it too early on.) + * it too early on. Always use on-slab management when + * SLAB_NOLEAKTRACE to avoid recursive calls into kmemleak) */ - if ((size >= (PAGE_SIZE >> 3)) && !slab_early_init) + if ((size >= (PAGE_SIZE >> 3)) && !slab_early_init && + !(flags & SLAB_NOLEAKTRACE)) /* * Size is large, assume best to place the slab management obj * off-slab (should allow better packing of objs). -- cgit v1.2.3 From c017b4be3e84176cab10eca5e6c4faeb8cfc6f3e Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Wed, 28 Oct 2009 13:33:09 +0000 Subject: kmemleak: Simplify the kmemleak_scan_area() function prototype This function was taking non-necessary arguments which can be determined by kmemleak. The patch also modifies the calling sites. Signed-off-by: Catalin Marinas Cc: Pekka Enberg Cc: Christoph Lameter Cc: Rusty Russell --- include/linux/kmemleak.h | 6 ++---- kernel/module.c | 7 ++----- mm/kmemleak.c | 49 +++++++++++++++++++++--------------------------- mm/slab.c | 4 ++-- 4 files changed, 27 insertions(+), 39 deletions(-) (limited to 'mm/slab.c') diff --git a/include/linux/kmemleak.h b/include/linux/kmemleak.h index 3c7497d46ee9..99d9a6766f7e 100644 --- a/include/linux/kmemleak.h +++ b/include/linux/kmemleak.h @@ -32,8 +32,7 @@ extern void kmemleak_padding(const void *ptr, unsigned long offset, size_t size) __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, unsigned long offset, - size_t length, gfp_t gfp) __ref; +extern void kmemleak_scan_area(const void *ptr, size_t size, gfp_t gfp) __ref; extern void kmemleak_no_scan(const void *ptr) __ref; static inline void kmemleak_alloc_recursive(const void *ptr, size_t size, @@ -84,8 +83,7 @@ static inline void kmemleak_not_leak(const void *ptr) static inline void kmemleak_ignore(const void *ptr) { } -static inline void kmemleak_scan_area(const void *ptr, unsigned long offset, - size_t length, gfp_t gfp) +static inline void kmemleak_scan_area(const void *ptr, size_t size, gfp_t gfp) { } static inline void kmemleak_erase(void **ptr) diff --git a/kernel/module.c b/kernel/module.c index 8b7d8805819d..1eb952097077 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -2043,9 +2043,7 @@ static void kmemleak_load_module(struct module *mod, Elf_Ehdr *hdr, unsigned int i; /* only scan the sections containing data */ - kmemleak_scan_area(mod->module_core, (unsigned long)mod - - (unsigned long)mod->module_core, - sizeof(struct module), GFP_KERNEL); + kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL); for (i = 1; i < hdr->e_shnum; i++) { if (!(sechdrs[i].sh_flags & SHF_ALLOC)) @@ -2054,8 +2052,7 @@ static void kmemleak_load_module(struct module *mod, Elf_Ehdr *hdr, && strncmp(secstrings + sechdrs[i].sh_name, ".bss", 4) != 0) continue; - kmemleak_scan_area(mod->module_core, sechdrs[i].sh_addr - - (unsigned long)mod->module_core, + kmemleak_scan_area((void *)sechdrs[i].sh_addr, sechdrs[i].sh_size, GFP_KERNEL); } } diff --git a/mm/kmemleak.c b/mm/kmemleak.c index 8bf765c4f58d..96106358e042 100644 --- a/mm/kmemleak.c +++ b/mm/kmemleak.c @@ -119,8 +119,8 @@ /* scanning area inside a memory block */ struct kmemleak_scan_area { struct hlist_node node; - unsigned long offset; - size_t length; + unsigned long start; + size_t size; }; #define KMEMLEAK_GREY 0 @@ -241,8 +241,6 @@ struct early_log { const void *ptr; /* allocated/freed memory block */ size_t size; /* memory block size */ int min_count; /* minimum reference count */ - unsigned long offset; /* scan area offset */ - size_t length; /* scan area length */ unsigned long trace[MAX_TRACE]; /* stack trace */ unsigned int trace_len; /* stack trace length */ }; @@ -720,14 +718,13 @@ static void make_black_object(unsigned long ptr) * Add a scanning area to the object. If at least one such area is added, * kmemleak will only scan these ranges rather than the whole memory block. */ -static void add_scan_area(unsigned long ptr, unsigned long offset, - size_t length, gfp_t gfp) +static void add_scan_area(unsigned long ptr, size_t size, gfp_t gfp) { unsigned long flags; struct kmemleak_object *object; struct kmemleak_scan_area *area; - object = find_and_get_object(ptr, 0); + object = find_and_get_object(ptr, 1); if (!object) { kmemleak_warn("Adding scan area to unknown object at 0x%08lx\n", ptr); @@ -741,7 +738,7 @@ static void add_scan_area(unsigned long ptr, unsigned long offset, } spin_lock_irqsave(&object->lock, flags); - if (offset + length > object->size) { + if (ptr + size > object->pointer + object->size) { kmemleak_warn("Scan area larger than object 0x%08lx\n", ptr); dump_object_info(object); kmem_cache_free(scan_area_cache, area); @@ -749,8 +746,8 @@ static void add_scan_area(unsigned long ptr, unsigned long offset, } INIT_HLIST_NODE(&area->node); - area->offset = offset; - area->length = length; + area->start = ptr; + area->size = size; hlist_add_head(&area->node, &object->area_list); out_unlock: @@ -786,7 +783,7 @@ static void object_no_scan(unsigned long ptr) * processed later once kmemleak is fully initialized. */ static void __init log_early(int op_type, const void *ptr, size_t size, - int min_count, unsigned long offset, size_t length) + int min_count) { unsigned long flags; struct early_log *log; @@ -808,8 +805,6 @@ static void __init log_early(int op_type, const void *ptr, size_t size, log->ptr = ptr; log->size = size; log->min_count = min_count; - log->offset = offset; - log->length = length; if (op_type == KMEMLEAK_ALLOC) log->trace_len = __save_stack_trace(log->trace); crt_early_log++; @@ -858,7 +853,7 @@ void __ref kmemleak_alloc(const void *ptr, size_t size, int min_count, if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr)) create_object((unsigned long)ptr, size, min_count, gfp); else if (atomic_read(&kmemleak_early_log)) - log_early(KMEMLEAK_ALLOC, ptr, size, min_count, 0, 0); + log_early(KMEMLEAK_ALLOC, ptr, size, min_count); } EXPORT_SYMBOL_GPL(kmemleak_alloc); @@ -873,7 +868,7 @@ void __ref kmemleak_free(const void *ptr) if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr)) delete_object_full((unsigned long)ptr); else if (atomic_read(&kmemleak_early_log)) - log_early(KMEMLEAK_FREE, ptr, 0, 0, 0, 0); + log_early(KMEMLEAK_FREE, ptr, 0, 0); } EXPORT_SYMBOL_GPL(kmemleak_free); @@ -888,7 +883,7 @@ void __ref kmemleak_free_part(const void *ptr, size_t size) if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr)) delete_object_part((unsigned long)ptr, size); else if (atomic_read(&kmemleak_early_log)) - log_early(KMEMLEAK_FREE_PART, ptr, size, 0, 0, 0); + log_early(KMEMLEAK_FREE_PART, ptr, size, 0); } EXPORT_SYMBOL_GPL(kmemleak_free_part); @@ -903,7 +898,7 @@ void __ref kmemleak_not_leak(const void *ptr) if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr)) make_gray_object((unsigned long)ptr); else if (atomic_read(&kmemleak_early_log)) - log_early(KMEMLEAK_NOT_LEAK, ptr, 0, 0, 0, 0); + log_early(KMEMLEAK_NOT_LEAK, ptr, 0, 0); } EXPORT_SYMBOL(kmemleak_not_leak); @@ -919,22 +914,21 @@ void __ref kmemleak_ignore(const void *ptr) if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr)) make_black_object((unsigned long)ptr); else if (atomic_read(&kmemleak_early_log)) - log_early(KMEMLEAK_IGNORE, ptr, 0, 0, 0, 0); + log_early(KMEMLEAK_IGNORE, ptr, 0, 0); } EXPORT_SYMBOL(kmemleak_ignore); /* * Limit the range to be scanned in an allocated memory block. */ -void __ref kmemleak_scan_area(const void *ptr, unsigned long offset, - size_t length, gfp_t gfp) +void __ref kmemleak_scan_area(const void *ptr, size_t size, gfp_t gfp) { pr_debug("%s(0x%p)\n", __func__, ptr); if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr)) - add_scan_area((unsigned long)ptr, offset, length, gfp); + add_scan_area((unsigned long)ptr, size, gfp); else if (atomic_read(&kmemleak_early_log)) - log_early(KMEMLEAK_SCAN_AREA, ptr, 0, 0, offset, length); + log_early(KMEMLEAK_SCAN_AREA, ptr, size, 0); } EXPORT_SYMBOL(kmemleak_scan_area); @@ -948,7 +942,7 @@ void __ref kmemleak_no_scan(const void *ptr) if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr)) object_no_scan((unsigned long)ptr); else if (atomic_read(&kmemleak_early_log)) - log_early(KMEMLEAK_NO_SCAN, ptr, 0, 0, 0, 0); + log_early(KMEMLEAK_NO_SCAN, ptr, 0, 0); } EXPORT_SYMBOL(kmemleak_no_scan); @@ -1075,9 +1069,9 @@ static void scan_object(struct kmemleak_object *object) } } else hlist_for_each_entry(area, elem, &object->area_list, node) - scan_block((void *)(object->pointer + area->offset), - (void *)(object->pointer + area->offset - + area->length), object, 0); + scan_block((void *)area->start, + (void *)(area->start + area->size), + object, 0); out: spin_unlock_irqrestore(&object->lock, flags); } @@ -1642,8 +1636,7 @@ void __init kmemleak_init(void) kmemleak_ignore(log->ptr); break; case KMEMLEAK_SCAN_AREA: - kmemleak_scan_area(log->ptr, log->offset, log->length, - GFP_KERNEL); + kmemleak_scan_area(log->ptr, log->size, GFP_KERNEL); break; case KMEMLEAK_NO_SCAN: kmemleak_no_scan(log->ptr); diff --git a/mm/slab.c b/mm/slab.c index 646db3085193..d2713a944ebd 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -2584,8 +2584,8 @@ static struct slab *alloc_slabmgmt(struct kmem_cache *cachep, void *objp, * kmemleak does not treat the ->s_mem pointer as a reference * to the object. Otherwise we will not report the leak. */ - kmemleak_scan_area(slabp, offsetof(struct slab, list), - sizeof(struct list_head), local_flags); + kmemleak_scan_area(&slabp->list, sizeof(struct list_head), + local_flags); if (!slabp) return NULL; } else { -- cgit v1.2.3