On Mon, Nov 23, 2015 at 06:36:42PM +0100, Piotr Kwapulinski wrote: > 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. > > Remove the code that makes no sense. > > Signed-off-by: Piotr Kwapulinski <kwapulinski.pi...@gmail.com>
Looks good to me. Thank you. Reviewed-by: Naoya Horiguchi <n-horigu...@ah.jp.nec.com> > --- > mm/mmap.c | 3 --- > 1 file changed, 3 deletions(-) > > diff --git a/mm/mmap.c b/mm/mmap.c > index 2ce04a6..42a8259 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)) > -- > 2.6.2 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
