+ ipcshm-move-bug_on-check-into-shm_lock.patch added to -mm tree

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



The patch titled
     Subject: ipc,shm: move BUG_ON check into shm_lock
has been added to the -mm tree.  Its filename is
     ipcshm-move-bug_on-check-into-shm_lock.patch

This patch should soon appear at
    http://ozlabs.org/~akpm/mmots/broken-out/ipcshm-move-bug_on-check-into-shm_lock.patch
and later at
    http://ozlabs.org/~akpm/mmotm/broken-out/ipcshm-move-bug_on-check-into-shm_lock.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 <dave@xxxxxxxxxxxx>
Subject: ipc,shm: move BUG_ON check into shm_lock

Upon every shm_lock call, we BUG_ON if an error was returned, indicating
racing either in idr or in shm_destroy.  Move this logic into the locking.

Signed-off-by: Davidlohr Bueso <dbueso@xxxxxxx>
Cc: Manfred Spraul <manfred@xxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---

 ipc/shm.c |   11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff -puN ipc/shm.c~ipcshm-move-bug_on-check-into-shm_lock ipc/shm.c
--- a/ipc/shm.c~ipcshm-move-bug_on-check-into-shm_lock
+++ a/ipc/shm.c
@@ -155,8 +155,14 @@ static inline struct shmid_kernel *shm_l
 {
 	struct kern_ipc_perm *ipcp = ipc_lock(&shm_ids(ns), id);
 
-	if (IS_ERR(ipcp))
+	if (IS_ERR(ipcp)) {
+		/*
+		 * We raced in the idr lookup or with shm_destroy(),
+		 * either way, the ID is busted.
+		 */
+		BUG();
 		return (struct shmid_kernel *)ipcp;
+	}
 
 	return container_of(ipcp, struct shmid_kernel, shm_perm);
 }
@@ -191,7 +197,6 @@ static void shm_open(struct vm_area_stru
 	struct shmid_kernel *shp;
 
 	shp = shm_lock(sfd->ns, sfd->id);
-	BUG_ON(IS_ERR(shp));
 	shp->shm_atim = get_seconds();
 	shp->shm_lprid = task_tgid_vnr(current);
 	shp->shm_nattch++;
@@ -258,7 +263,6 @@ static void shm_close(struct vm_area_str
 	down_write(&shm_ids(ns).rwsem);
 	/* remove from the list of attaches of the shm segment */
 	shp = shm_lock(ns, sfd->id);
-	BUG_ON(IS_ERR(shp));
 	shp->shm_lprid = task_tgid_vnr(current);
 	shp->shm_dtim = get_seconds();
 	shp->shm_nattch--;
@@ -1191,7 +1195,6 @@ out_fput:
 out_nattch:
 	down_write(&shm_ids(ns).rwsem);
 	shp = shm_lock(ns, shmid);
-	BUG_ON(IS_ERR(shp));
 	shp->shm_nattch--;
 	if (shm_may_destroy(ns, shp))
 		shm_destroy(ns, shp);
_

Patches currently in -mm which might be from dave@xxxxxxxxxxxx are

mm-hugetlb-document-the-reserve-map-region-tracking-routines.patch
mm-hugetlb-compute-return-the-number-of-regions-added-by-region_add.patch
mm-hugetlb-handle-races-in-alloc_huge_page-and-hugetlb_reserve_pages.patch
mm-hugetlb-handle-races-in-alloc_huge_page-and-hugetlb_reserve_pages-v4.patch
ipcshm-move-bug_on-check-into-shm_lock.patch
ipcmsg-provide-barrier-pairings-for-lockless-receive.patch
ipc-rename-ipc_obtain_object.patch
ipcsysv-make-return-eidrm-when-racing-with-rmid-consistent.patch
ipcsysv-return-einval-upon-incorrect-id-seqnum.patch
linux-next.patch

--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html




[Index of Archives]     [Kernel Newbies FAQ]     [Kernel Archive]     [IETF Annouce]     [DCCP]     [Netdev]     [Networking]     [Security]     [Bugtraq]     [Photo]     [Yosemite]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Linux SCSI]

  Powered by Linux