do not limit locked memory when RLIMIT_MEMLOCK is RLIM_INFINITY

Fix a bug in mm/mlock.c on 32-bit architectures that prevents a user from
locking more than 4GB of shared memory, or allocating more than 4GB of
shared memory in hugepages, when rlim[RLIMIT_MEMLOCK] is set to
RLIM_INFINITY.

Signed-off-by: Herbert van den Bergh <[email protected]>
Acked-by: Chris Mason <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
This commit is contained in:
Herbert van den Bergh 2007-07-15 23:38:25 -07:00 • committed by Linus Torvalds
commit 5ed44a401d

View file

@ -244,9 +244,12 @@ int user_shm_lock(size_t size, struct user_struct *user)
locked = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur;
if (lock_limit == RLIM_INFINITY)
allowed = 1;
lock_limit >>= PAGE_SHIFT;
spin_lock(&shmlock_user_lock);
if (locked + user->locked_shm > lock_limit && !capable(CAP_IPC_LOCK))
if (!allowed &&
locked + user->locked_shm > lock_limit && !capable(CAP_IPC_LOCK))
goto out;
get_uid(user);
user->locked_shm += locked;