tree 37bf115305df3fefce7d0c68b531adfa92085d36
parent 79a81aef769f3a188988ad16032ccfc445cfaa13
author Eric W. Biederman <ebiederm@xmission.com> 1171270330 -0800
committer Linus Torvalds <torvalds@woody.linux-foundation.org> 1171302509 -0800

[PATCH] ipc: save the ipc namespace while reading proc files

The problem we were assuming that current->nsproxy->ipc_ns would never
change while someone has our file in /proc/sysvipc/ file open.  Given that
this can change with both unshare and by passing the file descriptor to
another process that assumption is occasionally wrong.

Therefore this patch causes /proc/sysvipc/* to cache the namespace and
increment it's count when we open the file and to decrement the count when
we close the file, ensuring consistent operation with no surprises.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Serge E. Hallyn <serue@us.ibm.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Kirill Korotaev <dev@sw.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>