From: Paul E. McKenney Date: Sat, 25 Jun 2005 21:55:38 +0000 (-0700) Subject: [PATCH] RCU: clean up a few remaining synchronize_kernel() calls X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=b2b18660066997420b716c1881a6be8b82700d97;p=openwrt%2Fstaging%2Fblogic.git [PATCH] RCU: clean up a few remaining synchronize_kernel() calls 2.6.12-rc6-mm1 has a few remaining synchronize_kernel()s, some (but not all) in comments. This patch changes these synchronize_kernel() calls (and comments) to synchronize_rcu() or synchronize_sched() as follows: - arch/x86_64/kernel/mce.c mce_read(): change to synchronize_sched() to handle races with machine-check exceptions (synchronize_rcu() would not cut it given RCU implementations intended for hardcore realtime use. - drivers/input/serio/i8042.c i8042_stop(): change to synchronize_sched() to handle races with i8042_interrupt() interrupt handler. Again, synchronize_rcu() would not cut it given RCU implementations intended for hardcore realtime use. - include/*/kdebug.h comments: change to synchronize_sched() to handle races with NMIs. As before, synchronize_rcu() would not cut it... - include/linux/list.h comment: change to synchronize_rcu(), since this comment is for list_del_rcu(). - security/keys/key.c unregister_key_type(): change to synchronize_rcu(), since this is interacting with RCU read side. - security/keys/process_keys.c install_session_keyring(): change to synchronize_rcu(), since this is interacting with RCU read side. Signed-off-by: "Paul E. McKenney" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/arch/x86_64/kernel/mce.c b/arch/x86_64/kernel/mce.c index 7ab15c8ab95f..21e70625a495 100644 --- a/arch/x86_64/kernel/mce.c +++ b/arch/x86_64/kernel/mce.c @@ -411,7 +411,7 @@ static ssize_t mce_read(struct file *filp, char __user *ubuf, size_t usize, loff memset(mcelog.entry, 0, next * sizeof(struct mce)); mcelog.next = 0; - synchronize_kernel(); + synchronize_sched(); /* Collect entries that were still getting written before the synchronize. */ diff --git a/drivers/input/serio/i8042.c b/drivers/input/serio/i8042.c index 5900de3c3f4f..a9bf549c8dc5 100644 --- a/drivers/input/serio/i8042.c +++ b/drivers/input/serio/i8042.c @@ -396,7 +396,7 @@ static void i8042_stop(struct serio *serio) struct i8042_port *port = serio->port_data; port->exists = 0; - synchronize_kernel(); + synchronize_sched(); port->serio = NULL; } diff --git a/include/asm-i386/kdebug.h b/include/asm-i386/kdebug.h index de6498b0d493..b3f8d5f59d5d 100644 --- a/include/asm-i386/kdebug.h +++ b/include/asm-i386/kdebug.h @@ -18,7 +18,7 @@ struct die_args { }; /* Note - you should never unregister because that can race with NMIs. - If you really want to do it first unregister - then synchronize_kernel - then free. + If you really want to do it first unregister - then synchronize_sched - then free. */ int register_die_notifier(struct notifier_block *nb); extern struct notifier_block *i386die_chain; diff --git a/include/asm-ppc64/kdebug.h b/include/asm-ppc64/kdebug.h index 488634258a72..d383d161cf8d 100644 --- a/include/asm-ppc64/kdebug.h +++ b/include/asm-ppc64/kdebug.h @@ -17,7 +17,7 @@ struct die_args { /* Note - you should never unregister because that can race with NMIs. - If you really want to do it first unregister - then synchronize_kernel - + If you really want to do it first unregister - then synchronize_sched - then free. */ int register_die_notifier(struct notifier_block *nb); diff --git a/include/asm-sparc64/kdebug.h b/include/asm-sparc64/kdebug.h index f70d3dad01f9..6321f5a0198d 100644 --- a/include/asm-sparc64/kdebug.h +++ b/include/asm-sparc64/kdebug.h @@ -16,7 +16,7 @@ struct die_args { }; /* Note - you should never unregister because that can race with NMIs. - * If you really want to do it first unregister - then synchronize_kernel + * If you really want to do it first unregister - then synchronize_sched * - then free. */ int register_die_notifier(struct notifier_block *nb); diff --git a/include/asm-x86_64/kdebug.h b/include/asm-x86_64/kdebug.h index 6277f75cbb4b..b90341994d80 100644 --- a/include/asm-x86_64/kdebug.h +++ b/include/asm-x86_64/kdebug.h @@ -14,7 +14,7 @@ struct die_args { }; /* Note - you should never unregister because that can race with NMIs. - If you really want to do it first unregister - then synchronize_kernel - then free. + If you really want to do it first unregister - then synchronize_sched - then free. */ int register_die_notifier(struct notifier_block *nb); extern struct notifier_block *die_chain; diff --git a/include/linux/list.h b/include/linux/list.h index 399b51d17218..aab2db21b013 100644 --- a/include/linux/list.h +++ b/include/linux/list.h @@ -185,7 +185,7 @@ static inline void list_del(struct list_head *entry) * list_for_each_entry_rcu(). * * Note that the caller is not permitted to immediately free - * the newly deleted entry. Instead, either synchronize_kernel() + * the newly deleted entry. Instead, either synchronize_rcu() * or call_rcu() must be used to defer freeing until an RCU * grace period has elapsed. */ diff --git a/security/keys/key.c b/security/keys/key.c index 3304d37bb379..fb89f9844465 100644 --- a/security/keys/key.c +++ b/security/keys/key.c @@ -980,7 +980,7 @@ void unregister_key_type(struct key_type *ktype) spin_unlock(&key_serial_lock); /* make sure everyone revalidates their keys */ - synchronize_kernel(); + synchronize_rcu(); /* we should now be able to destroy the payloads of all the keys of * this type with impunity */ diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c index 34db087bbcc7..9b0369c5a223 100644 --- a/security/keys/process_keys.c +++ b/security/keys/process_keys.c @@ -234,7 +234,7 @@ static int install_session_keyring(struct task_struct *tsk, ret = 0; /* we're using RCU on the pointer */ - synchronize_kernel(); + synchronize_rcu(); key_put(old); error: return ret;