Commit 9943242c authored by Oleg Nesterov's avatar Oleg Nesterov Committed by Linus Torvalds

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: default avatarOleg Nesterov <oleg@redhat.com>
Acked-by: default avatarDavid 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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 1d391686
...@@ -407,13 +407,8 @@ static unsigned long mremap_to(unsigned long addr, unsigned long old_len, ...@@ -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) if (new_len > TASK_SIZE || new_addr > TASK_SIZE - new_len)
goto out; goto out;
/* Check if the location we're moving into overlaps the /* Ensure the old/new locations do not overlap */
* old location at all, and fail if it does. if (addr + old_len > new_addr && new_addr + new_len > addr)
*/
if ((new_addr <= addr) && (new_addr+new_len) > addr)
goto out;
if ((addr <= new_addr) && (addr+old_len) > new_addr)
goto out; goto out;
ret = do_munmap(mm, new_addr, new_len); ret = do_munmap(mm, new_addr, new_len);
......
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