linux 2.6.16.38 w/ vs2.0.3-rc1

[linux-2.6.git] / security / keys / process_keys.c

diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c
index 217a0be..74cb79e 100644 (file)
--- a/security/keys/process_keys.c
+++ b/security/keys/process_keys.c
@@ -16,12 +16,11 @@
 #include <linux/keyctl.h>
 #include <linux/fs.h>
 #include <linux/err.h>
-#include <linux/mutex.h>
 #include <asm/uaccess.h>
 #include "internal.h"
 
 /* session keyring create vs join semaphore */
-static DEFINE_MUTEX(key_session_mutex);
+static DECLARE_MUTEX(key_session_sem);
 
 /* the root user's tracking struct */
 struct key_user root_key_user = {
@@ -168,12 +167,11 @@ error:
  */
 int install_process_keyring(struct task_struct *tsk)
 {
+       unsigned long flags;
        struct key *keyring;
        char buf[20];
        int ret;
 
-       might_sleep();
-
        if (!tsk->signal->process_keyring) {
                sprintf(buf, "_pid.%u", tsk->tgid);
 
@@ -184,12 +182,12 @@ int install_process_keyring(struct task_struct *tsk)
                }
 
                /* attach keyring */
-               spin_lock_irq(&tsk->sighand->siglock);
+               spin_lock_irqsave(&tsk->sighand->siglock, flags);
                if (!tsk->signal->process_keyring) {
                        tsk->signal->process_keyring = keyring;
                        keyring = NULL;
                }
-               spin_unlock_irq(&tsk->sighand->siglock);
+               spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
 
                key_put(keyring);
        }
@@ -208,37 +206,38 @@ error:
 static int install_session_keyring(struct task_struct *tsk,
                                   struct key *keyring)
 {
+       unsigned long flags;
        struct key *old;
        char buf[20];
-
-       might_sleep();
+       int ret;
 
        /* create an empty session keyring */
        if (!keyring) {
                sprintf(buf, "_ses.%u", tsk->tgid);
 
                keyring = keyring_alloc(buf, tsk->uid, tsk->gid, 1, NULL);
-               if (IS_ERR(keyring))
-                       return PTR_ERR(keyring);
+               if (IS_ERR(keyring)) {
+                       ret = PTR_ERR(keyring);
+                       goto error;
+               }
        }
        else {
                atomic_inc(&keyring->usage);
        }
 
        /* install the keyring */
-       spin_lock_irq(&tsk->sighand->siglock);
-       old = tsk->signal->session_keyring;
+       spin_lock_irqsave(&tsk->sighand->siglock, flags);
+       old = rcu_dereference(tsk->signal->session_keyring);
        rcu_assign_pointer(tsk->signal->session_keyring, keyring);
-       spin_unlock_irq(&tsk->sighand->siglock);
+       spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
 
-       /* we're using RCU on the pointer, but there's no point synchronising
-        * on it if it didn't previously point to anything */
-       if (old) {
-               synchronize_rcu();
-               key_put(old);
-       }
+       ret = 0;
 
-       return 0;
+       /* we're using RCU on the pointer */
+       synchronize_rcu();
+       key_put(old);
+error:
+       return ret;
 
 } /* end install_session_keyring() */
 
@@ -311,6 +310,7 @@ void exit_keys(struct task_struct *tsk)
  */
 int exec_keys(struct task_struct *tsk)
 {
+       unsigned long flags;
        struct key *old;
 
        /* newly exec'd tasks don't get a thread keyring */
@@ -322,10 +322,10 @@ int exec_keys(struct task_struct *tsk)
        key_put(old);
 
        /* discard the process keyring from a newly exec'd task */
-       spin_lock_irq(&tsk->sighand->siglock);
+       spin_lock_irqsave(&tsk->sighand->siglock, flags);
        old = tsk->signal->process_keyring;
        tsk->signal->process_keyring = NULL;
-       spin_unlock_irq(&tsk->sighand->siglock);
+       spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
 
        key_put(old);
 
@@ -711,7 +711,7 @@ long join_session_keyring(const char *name)
        }
 
        /* allow the user to join or create a named keyring */
-       mutex_lock(&key_session_mutex);
+       down(&key_session_sem);
 
        /* look for an existing keyring of this name */
        keyring = find_keyring_by_name(name, 0);
@@ -737,7 +737,7 @@ long join_session_keyring(const char *name)
        key_put(keyring);
 
 error2:
-       mutex_unlock(&key_session_mutex);
+       up(&key_session_sem);
 error:
        return ret;