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| author | David Howells <dhowells@redhat.com> | 2005-06-23 22:00:53 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-06-24 00:05:18 -0700 |
| commit | 8589b4e00e352f983259140f25a262d973be6bc5 (patch) | |
| tree | d53c9b43ee0aaa2d7518a023c4b6373422117506 /security/keys/request_key.c | |
| parent | 7888e7ff4ee579442128d7d12a9c9dbf2cf7de6a (diff) | |
| download | lwn-8589b4e00e352f983259140f25a262d973be6bc5.tar.gz lwn-8589b4e00e352f983259140f25a262d973be6bc5.zip | |
[PATCH] Keys: Use RCU to manage session keyring pointer
The attached patch uses RCU to manage the session keyring pointer in struct
signal_struct. This means that searching need not disable interrupts and get
a the sighand spinlock to access this pointer. Furthermore, by judicious use
of rcu_read_(un)lock(), this patch also avoids the need to take and put
refcounts on the session keyring itself, thus saving on even more atomic ops.
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'security/keys/request_key.c')
| -rw-r--r-- | security/keys/request_key.c | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/security/keys/request_key.c b/security/keys/request_key.c index 1919540f047d..54aa7b70e63b 100644 --- a/security/keys/request_key.c +++ b/security/keys/request_key.c @@ -175,13 +175,12 @@ static struct key *__request_key_construction(struct key_type *type, key->expiry = now.tv_sec + key_negative_timeout; if (current->signal->session_keyring) { - unsigned long flags; struct key *keyring; - spin_lock_irqsave(¤t->sighand->siglock, flags); - keyring = current->signal->session_keyring; + rcu_read_lock(); + keyring = rcu_dereference(current->signal->session_keyring); atomic_inc(&keyring->usage); - spin_unlock_irqrestore(¤t->sighand->siglock, flags); + rcu_read_unlock(); key_link(keyring, key); key_put(keyring); |