diff options
| author | Oleg Nesterov <oleg@redhat.com> | 2015-09-05 00:48:13 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-09-05 01:54:41 +0200 |
| commit | 9943242ca468149c4ce30d4633524c0866d4a87b (patch) | |
| tree | a4ad8816368c646e29d299a12f2f4a06e87fe50c /mm/mremap.c | |
| parent | mremap: don't do uneccesary checks if new_len == old_len (diff) | |
| download | linux-9943242ca468149c4ce30d4633524c0866d4a87b.tar.xz linux-9943242ca468149c4ce30d4633524c0866d4a87b.zip | |
mremap: simplify the "overlap" check in mremap_to()
Minor, but this check is overcomplicated. Two half-intervals do NOT
overlap if END1 <= START2 || END2 <= START1, mremap_to() just needs to
negate this check.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/mremap.c')
| -rw-r--r-- | mm/mremap.c | 9 |
1 files changed, 2 insertions, 7 deletions
diff --git a/mm/mremap.c b/mm/mremap.c index d3f42bece564..5a71cce8c6ea 100644 --- a/mm/mremap.c +++ b/mm/mremap.c @@ -407,13 +407,8 @@ static unsigned long mremap_to(unsigned long addr, unsigned long old_len, if (new_len > TASK_SIZE || new_addr > TASK_SIZE - new_len) goto out; - /* Check if the location we're moving into overlaps the - * old location at all, and fail if it does. - */ - if ((new_addr <= addr) && (new_addr+new_len) > addr) - goto out; - - if ((addr <= new_addr) && (addr+old_len) > new_addr) + /* Ensure the old/new locations do not overlap */ + if (addr + old_len > new_addr && new_addr + new_len > addr) goto out; ret = do_munmap(mm, new_addr, new_len); |