• Michal Hocko's avatar
    mm: make vm_mmap killable · 9fbeb5ab
    Michal Hocko authored
    
    
    All the callers of vm_mmap seem to check for the failure already and
    bail out in one way or another on the error which means that we can
    change it to use killable version of vm_mmap_pgoff and return -EINTR if
    the current task gets killed while waiting for mmap_sem.  This also
    means that vm_mmap_pgoff can be killable by default and drop the
    additional parameter.
    
    This will help in the OOM conditions when the oom victim might be stuck
    waiting for the mmap_sem for write which in turn can block oom_reaper
    which relies on the mmap_sem for read to make a forward progress and
    reclaim the address space of the victim.
    
    Please note that load_elf_binary is ignoring vm_mmap error for
    current->personality & MMAP_PAGE_ZERO case but that shouldn't be a
    problem because the address is not used anywhere and we never return to
    the userspace if we got killed.
    Signed-off-by: default avatarMichal Hocko <mhocko@suse.com>
    Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
    Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
    Cc: Mel Gorman <mgorman@suse.de>
    Cc: Oleg Nesterov <oleg@redhat.com>
    Cc: Andrea Arcangeli <aarcange@redhat.com>
    Cc: Al Viro <viro@zeniv.linux.org.uk>
    Cc: Johannes Weiner <hannes@cmpxchg.org>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    9fbeb5ab
util.c 15.5 KB