+ ipcsem-fine-grained-locking-for-semtimedop-fix-fix.patch added to -mm tree

+ ipcsem-fine-grained-locking-for-semtimedop-fix-fix.patch added to -mm tree

[akpm]

The patch titled
     Subject: ipc,sem: fix lockdep false positive
has been added to the -mm tree.  Its filename is
     ipcsem-fine-grained-locking-for-semtimedop-fix-fix.patch

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/SubmitChecklist when testing your code ***

The -mm tree is included into linux-next and is updated
there every 3-4 working days

------------------------------------------------------
From: Rik van Riel <riel@surriel.com>
Subject: ipc,sem: fix lockdep false positive

When locking all the semaphores inside a sem_array, the kernel ends up
locking a large number of locks with identical lockdep status. This
trips up lockdep.  Annotate the code to prevent such warnings.

Signed-off-by: Rik van Riel <riel@redhat.com>
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 ipc/sem.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff -puN ipc/sem.c~ipcsem-fine-grained-locking-for-semtimedop-fix-fix ipc/sem.c
--- a/ipc/sem.c~ipcsem-fine-grained-locking-for-semtimedop-fix-fix
+++ a/ipc/sem.c
@@ -227,7 +227,7 @@ static inline int sem_lock(struct sem_ar
 		spin_lock(&sma->sem_perm.lock);
 		for (i = 0; i < sma->sem_nsems; i++) {
 			struct sem *sem = sma->sem_base + i;
-			spin_lock(&sem->lock);
+			spin_lock_nested(&sem->lock, SINGLE_DEPTH_NESTING);
 		}
 		locknum = -1;
 	}
@@ -426,7 +426,7 @@ static int newary(struct ipc_namespace *
 	for (i = 0; i < nsems; i++) {
 		INIT_LIST_HEAD(&sma->sem_base[i].sem_pending);
 		spin_lock_init(&sma->sem_base[i].lock);
-		spin_lock(&sma->sem_base[i].lock);
+		spin_lock_nested(&sma->sem_base[i].lock, SINGLE_DEPTH_NESTING);
 	}
 
 	sma->complex_count = 0;
_

Patches currently in -mm which might be from riel@surriel.com are

ipcsem-open-code-and-rename-sem_lock.patch
ipcsem-open-code-and-rename-sem_lock-fix.patch
ipcsem-have-only-one-list-in-struct-sem_queue.patch
ipcsem-fine-grained-locking-for-semtimedop.patch
ipcsem-fine-grained-locking-for-semtimedop-fix.patch
ipcsem-fine-grained-locking-for-semtimedop-fix-fix.patch

+ ipcsem-fine-grained-locking-for-semtimedop-fix-fix.patch added to -mm tree

[akpm]

The patch titled
     Subject: ipc, sem: prevent possible deadlock
has been added to the -mm tree.  Its filename is
     ipcsem-fine-grained-locking-for-semtimedop-fix-fix.patch

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/SubmitChecklist when testing your code ***

The -mm tree is included into linux-next and is updated
there every 3-4 working days

------------------------------------------------------
From: Davidlohr Bueso <davidlohr.bueso@hp.com>
Subject: ipc, sem: prevent possible deadlock

In semctl_main(), when cmd == GETALL, we're locking sma->sem_perm.lock
(through sem_lock_and_putref), yet after the conditional, we lock it
again.  Unlock sma right after exiting the conditional.

Signed-off-by: Davidlohr Bueso <davidlohr.bueso@hp.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 ipc/sem.c |    1 +
 1 file changed, 1 insertion(+)

diff -puN ipc/sem.c~ipcsem-fine-grained-locking-for-semtimedop-fix-fix ipc/sem.c
--- a/ipc/sem.c~ipcsem-fine-grained-locking-for-semtimedop-fix-fix
+++ a/ipc/sem.c
@@ -1115,6 +1115,7 @@ static int semctl_main(struct ipc_namesp
 				err = -EIDRM;
 				goto out_free;
 			}
+			sem_unlock(sma, -1);
 		}
 
 		sem_lock(sma, NULL, -1);
_

Patches currently in -mm which might be from davidlohr.bueso@hp.com are

lib-int_sqrtc-optimize-square-root-algorithm.patch
ipc-remove-bogus-lock-comment-for-ipc_checkid.patch
ipc-introduce-obtaining-a-lockless-ipc-object.patch
ipc-introduce-obtaining-a-lockless-ipc-object-fix.patch
ipc-introduce-lockless-pre_down-ipcctl.patch
ipcsem-do-not-hold-ipc-lock-more-than-necessary.patch
ipcsem-open-code-and-rename-sem_lock.patch
ipcsem-open-code-and-rename-sem_lock-fix.patch
ipcsem-have-only-one-list-in-struct-sem_queue.patch
ipcsem-fine-grained-locking-for-semtimedop.patch
ipcsem-fine-grained-locking-for-semtimedop-fix-fix.patch