From 9fbeb5ab59a2b2a09cca2eb68283e7a090d4b98d Mon Sep 17 00:00:00 2001 From: Michal Hocko Date: Mon, 23 May 2016 16:25:30 -0700 Subject: mm: make vm_mmap killable 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: Michal Hocko Acked-by: Vlastimil Babka Cc: "Kirill A. Shutemov" Cc: Mel Gorman Cc: Oleg Nesterov Cc: Andrea Arcangeli Cc: Al Viro Cc: Johannes Weiner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/mmap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'mm/mmap.c') diff --git a/mm/mmap.c b/mm/mmap.c index 11e1f2ca72af..420088682d4a 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1333,7 +1333,7 @@ SYSCALL_DEFINE6(mmap_pgoff, unsigned long, addr, unsigned long, len, flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE); - retval = vm_mmap_pgoff(file, addr, len, prot, flags, pgoff, true); + retval = vm_mmap_pgoff(file, addr, len, prot, flags, pgoff); out_fput: if (file) fput(file); -- cgit v1.2.3