diff options
| author | Davidlohr Bueso <davidlohr@hp.com> | 2014-01-22 00:49:16 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-01-22 01:19:44 +0100 |
| commit | 1f1cd7054fe7f45e65dd4963d0a38e5ab7a57cae (patch) | |
| tree | 3296b8809eca9c4eb6db72a4d00d2c534b6c8db2 | |
| parent | mm/mmap.c: add mlock_future_check() helper (diff) | |
| download | linux-1f1cd7054fe7f45e65dd4963d0a38e5ab7a57cae.tar.xz linux-1f1cd7054fe7f45e65dd4963d0a38e5ab7a57cae.zip | |
mm/mlock: prepare params outside critical region
All mlock related syscalls prepare lock limits, lengths and start
parameters with the mmap_sem held. Move this logic outside of the
critical region. For the case of mlock, continue incrementing the
amount already locked by mm->locked_vm with the rwsem taken.
Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Cc: Rik van Riel <riel@redhat.com>
Reviewed-by: Michel Lespinasse <walken@google.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | mm/mlock.c | 18 |
1 files changed, 11 insertions, 7 deletions
diff --git a/mm/mlock.c b/mm/mlock.c index 192e6eebe4f2..10819ed4df3e 100644 --- a/mm/mlock.c +++ b/mm/mlock.c @@ -709,19 +709,21 @@ SYSCALL_DEFINE2(mlock, unsigned long, start, size_t, len) lru_add_drain_all(); /* flush pagevec */ - down_write(¤t->mm->mmap_sem); len = PAGE_ALIGN(len + (start & ~PAGE_MASK)); start &= PAGE_MASK; - locked = len >> PAGE_SHIFT; - locked += current->mm->locked_vm; - lock_limit = rlimit(RLIMIT_MEMLOCK); lock_limit >>= PAGE_SHIFT; + locked = len >> PAGE_SHIFT; + + down_write(¤t->mm->mmap_sem); + + locked += current->mm->locked_vm; /* check against resource limits */ if ((locked <= lock_limit) || capable(CAP_IPC_LOCK)) error = do_mlock(start, len, 1); + up_write(¤t->mm->mmap_sem); if (!error) error = __mm_populate(start, len, 0); @@ -732,11 +734,13 @@ SYSCALL_DEFINE2(munlock, unsigned long, start, size_t, len) { int ret; - down_write(¤t->mm->mmap_sem); len = PAGE_ALIGN(len + (start & ~PAGE_MASK)); start &= PAGE_MASK; + + down_write(¤t->mm->mmap_sem); ret = do_mlock(start, len, 0); up_write(¤t->mm->mmap_sem); + return ret; } @@ -781,12 +785,12 @@ SYSCALL_DEFINE1(mlockall, int, flags) if (flags & MCL_CURRENT) lru_add_drain_all(); /* flush pagevec */ - down_write(¤t->mm->mmap_sem); - lock_limit = rlimit(RLIMIT_MEMLOCK); lock_limit >>= PAGE_SHIFT; ret = -ENOMEM; + down_write(¤t->mm->mmap_sem); + if (!(flags & MCL_CURRENT) || (current->mm->total_vm <= lock_limit) || capable(CAP_IPC_LOCK)) ret = do_mlockall(flags); |