• Thierry Reding's avatar
    mm/cma: make kmemleak ignore CMA regions · 620951e2
    Thierry Reding authored
    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: default avatarThierry Reding <treding@nvidia.com>
    Cc: Michal Nazarewicz <mina86@mina86.com>
    Cc: Marek Szyprowski <m.szyprowski@samsung.com>
    Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
    Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
    Cc: Catalin Marinas <catalin.marinas@arm.com>
    Signed-off-by: default avatarStephen Rothwell <sfr@canb.auug.org.au>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    620951e2
cma.c 11.9 KB