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| author | Oleg Nesterov <oleg@redhat.com> | 2012-05-11 10:59:08 +1000 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2012-05-23 22:11:23 -0400 |
| commit | 413cd3d9abeaef590e5ce00564f7a443165db238 (patch) | |
| tree | fc7d254053793a95d1470f7c9eafb782d8cf91d6 /include/linux/key.h | |
| parent | 4d1d61a6b203d957777d73fcebf19d90b038b5b2 (diff) | |
| download | linux-413cd3d9abeaef590e5ce00564f7a443165db238.tar.gz linux-413cd3d9abeaef590e5ce00564f7a443165db238.tar.bz2 linux-413cd3d9abeaef590e5ce00564f7a443165db238.zip | |
keys: change keyctl_session_to_parent() to use task_work_add()
Change keyctl_session_to_parent() to use task_work_add() and move
key_replace_session_keyring() logic into task_work->func().
Note that we do task_work_cancel() before task_work_add() to ensure that
only one work can be pending at any time. This is important, we must not
allow user-space to abuse the parent's ->task_works list.
The callback, replace_session_keyring(), checks PF_EXITING. I guess this
is not really needed but looks better.
As a side effect, this fixes the (unlikely) race. The callers of
key_replace_session_keyring() and keyctl_session_to_parent() lack the
necessary barriers, the parent can miss the request.
Now we can remove task_struct->replacement_session_keyring and related
code.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: David Howells <dhowells@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Alexander Gordeev <agordeev@redhat.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: David Smith <dsmith@redhat.com>
Cc: "Frank Ch. Eigler" <fche@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Larry Woodman <lwoodman@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'include/linux/key.h')
| -rw-r--r-- | include/linux/key.h | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/include/linux/key.h b/include/linux/key.h index 5231800770e1..2a0ee11584e9 100644 --- a/include/linux/key.h +++ b/include/linux/key.h @@ -33,6 +33,8 @@ typedef uint32_t key_perm_t; struct key; +#define key_replace_session_keyring() do { } while (0) + #ifdef CONFIG_KEYS #undef KEY_DEBUGGING @@ -308,9 +310,6 @@ static inline bool key_is_instantiated(const struct key *key) #ifdef CONFIG_SYSCTL extern ctl_table key_sysctls[]; #endif - -extern void key_replace_session_keyring(void); - /* * the userspace interface */ @@ -334,7 +333,6 @@ extern void key_init(void); #define key_fsuid_changed(t) do { } while(0) #define key_fsgid_changed(t) do { } while(0) #define key_init() do { } while(0) -#define key_replace_session_keyring() do { } while(0) #endif /* CONFIG_KEYS */ #endif /* __KERNEL__ */ |