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| author | Piotr Kwapulinski <kwapulinski.piotr@gmail.com> | 2016-01-14 15:19:50 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-01-14 16:00:49 -0800 |
| commit | bc36f7017c39d1fe3c01aecd09cb2fe14753be90 (patch) | |
| tree | 6bdaa15704de5b59058cf65abce655393b81598d /mm/mmap.c | |
| parent | 9f6c399ddc369856d787bd43ccd43b19ed1e4e32 (diff) | |
| download | lwn-bc36f7017c39d1fe3c01aecd09cb2fe14753be90.tar.gz lwn-bc36f7017c39d1fe3c01aecd09cb2fe14753be90.zip | |
mm/mmap.c: remove incorrect MAP_FIXED flag comparison from mmap_region
The following flag comparison in mmap_region makes no sense:
if (!(vm_flags & MAP_FIXED))
return -ENOMEM;
The condition is always false and thus the above "return -ENOMEM" is
never executed. The vm_flags must not be compared with MAP_FIXED flag.
The vm_flags may only be compared with VM_* flags. MAP_FIXED has the
same value as VM_MAYREAD.
Hitting the rlimit is a slow path and find_vma_intersection should
realize that there is no overlapping VMA for !MAP_FIXED case pretty
quickly.
Signed-off-by: Piotr Kwapulinski <kwapulinski.piotr@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/mmap.c')
| -rw-r--r-- | mm/mmap.c | 3 |
1 files changed, 0 insertions, 3 deletions
diff --git a/mm/mmap.c b/mm/mmap.c index 9da9c27c33a2..c311bfd8005b 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1551,9 +1551,6 @@ unsigned long mmap_region(struct file *file, unsigned long addr, * MAP_FIXED may remove pages of mappings that intersects with * requested mapping. Account for the pages it would unmap. */ - if (!(vm_flags & MAP_FIXED)) - return -ENOMEM; - nr_pages = count_vma_pages_range(mm, addr, addr + len); if (!may_expand_vm(mm, (len >> PAGE_SHIFT) - nr_pages)) |