Eric Lee / smarc-ti-linux-kernel

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Commit 1f1cd7054fe7f45e65dd4963d0a38e5ab7a57cae

Authored by Davidlohr Bueso
Committed by Linus Torvalds
1 parent 363ee17f0f
Exists in master and in 16 other branches dlt-processor-sdk-linux-03.00.00.04, processor-sdk-linux-01.00.00, processor-sdk-linux-02.00.01, smarc-ti-linux-3.14.y, smarc-ti-linux-3.15.y, smarc-ti-lsk-linux-4.1.y, smarct3x-processor-sdk-04.01.00.06, smarct3x-processor-sdk-linux-02.00.01, smarct3x-processor-sdk-linux-03.00.00.04, smarct4x-800-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-04.01.00.06, smarct4x-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-linux-03.00.00.04, ti-linux-3.14.y, ti-linux-3.15.y, ti-lsk-linux-4.1.y

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>

Showing 1 changed file with 11 additions and 7 deletions Side-by-side Diff

... ... @@ -709,19 +709,21 @@
709 709  
710 710 lru_add_drain_all(); /* flush pagevec */
711 711  
712   - down_write(&current->mm->mmap_sem);
713 712 len = PAGE_ALIGN(len + (start & ~PAGE_MASK));
714 713 start &= PAGE_MASK;
715 714  
716   - locked = len >> PAGE_SHIFT;
717   - locked += current->mm->locked_vm;
718   -
719 715 lock_limit = rlimit(RLIMIT_MEMLOCK);
720 716 lock_limit >>= PAGE_SHIFT;
  717 + locked = len >> PAGE_SHIFT;
721 718  
  719 + down_write(&current->mm->mmap_sem);
  720 +
  721 + locked += current->mm->locked_vm;
  722 +
722 723 /* check against resource limits */
723 724 if ((locked <= lock_limit) || capable(CAP_IPC_LOCK))
724 725 error = do_mlock(start, len, 1);
  726 +
725 727 up_write(&current->mm->mmap_sem);
726 728 if (!error)
727 729 error = __mm_populate(start, len, 0);
728 730  
729 731  
... ... @@ -732,11 +734,13 @@
732 734 {
733 735 int ret;
734 736  
735   - down_write(&current->mm->mmap_sem);
736 737 len = PAGE_ALIGN(len + (start & ~PAGE_MASK));
737 738 start &= PAGE_MASK;
  739 +
  740 + down_write(&current->mm->mmap_sem);
738 741 ret = do_mlock(start, len, 0);
739 742 up_write(&current->mm->mmap_sem);
  743 +
740 744 return ret;
741 745 }
742 746  
743 747  
... ... @@ -781,12 +785,12 @@
781 785 if (flags & MCL_CURRENT)
782 786 lru_add_drain_all(); /* flush pagevec */
783 787  
784   - down_write(&current->mm->mmap_sem);
785   -
786 788 lock_limit = rlimit(RLIMIT_MEMLOCK);
787 789 lock_limit >>= PAGE_SHIFT;
788 790  
789 791 ret = -ENOMEM;
  792 + down_write(&current->mm->mmap_sem);
  793 +
790 794 if (!(flags & MCL_CURRENT) || (current->mm->total_vm <= lock_limit) ||
791 795 capable(CAP_IPC_LOCK))
792 796 ret = do_mlockall(flags);