From 620951e2745750de1482128615adc15b74ee37ed Mon Sep 17 00:00:00 2001 From: Thierry Reding Date: Fri, 12 Dec 2014 16:58:31 -0800 Subject: [PATCH] mm/cma: make kmemleak ignore CMA regions kmemleak will add allocations as objects to a pool. The memory allocated for each object in this pool is periodically searched for pointers to other allocated objects. This only works for memory that is mapped into the kernel's virtual address space, which happens not to be the case for most CMA regions. Furthermore, CMA regions are typically used to store data transferred to or from a device and therefore don't contain pointers to other objects. Without this, the kernel crashes on the first execution of the scan_gray_list() because it tries to access highmem. Perhaps a more appropriate fix would be to reject any object that can't map to a kernel virtual address? [akpm@linux-foundation.org: add comment] [akpm@linux-foundation.org: fix comment, per Catalin] [sfr@canb.auug.org.au: include linux/io.h for phys_to_virt()] Signed-off-by: Thierry Reding Cc: Michal Nazarewicz Cc: Marek Szyprowski Cc: Joonsoo Kim Cc: "Aneesh Kumar K.V" Cc: Catalin Marinas Signed-off-by: Stephen Rothwell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/cma.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/mm/cma.c b/mm/cma.c index 5c96d7a3ba9c..f8917629cbdd 100644 --- a/mm/cma.c +++ b/mm/cma.c @@ -33,6 +33,7 @@ #include #include #include +#include struct cma { unsigned long base_pfn; @@ -324,6 +325,11 @@ int __init cma_declare_contiguous(phys_addr_t base, } } + /* + * kmemleak scans/reads tracked objects for pointers to other + * objects but this address isn't mapped and accessible + */ + kmemleak_ignore(phys_to_virt(addr)); base = addr; }