From 7f88f88f83ed609650a01b18572e605ea50cd163 Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Tue, 12 Nov 2013 15:07:45 -0800 Subject: mm: kmemleak: avoid false negatives on vmalloc'ed objects Commit 248ac0e1943a ("mm/vmalloc: remove guard page from between vmap blocks") had the side effect of making vmap_area.va_end member point to the next vmap_area.va_start. This was creating an artificial reference to vmalloc'ed objects and kmemleak was rarely reporting vmalloc() leaks. This patch marks the vmap_area containing pointers explicitly and reduces the min ref_count to 2 as vm_struct still contains a reference to the vmalloc'ed object. The kmemleak add_scan_area() function has been improved to allow a SIZE_MAX argument covering the rest of the object (for simpler calling sites). Signed-off-by: Catalin Marinas Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/kmemleak.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'mm/kmemleak.c') diff --git a/mm/kmemleak.c b/mm/kmemleak.c index e126b0ef9ad2..31f01c5011e5 100644 --- a/mm/kmemleak.c +++ b/mm/kmemleak.c @@ -753,7 +753,9 @@ static void add_scan_area(unsigned long ptr, size_t size, gfp_t gfp) } spin_lock_irqsave(&object->lock, flags); - if (ptr + size > object->pointer + object->size) { + if (size == SIZE_MAX) { + size = object->pointer + object->size - ptr; + } else 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); -- cgit v1.2.3