Re: [PATCH -tip v9 17/26] notifier: Use NOKPROBE_SYMBOL macro in notifier

Josh Triplett
2014-04-17T14:40:48Z

On Thu, Apr 17, 2014 at 05:18:35PM +0900, Masami Hiramatsu wrote:
> Use NOKPROBE_SYMBOL macro to protect functions from
> kprobes instead of __kprobes annotation in notifier.
>
> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
> Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
> Cc: Josh Triplett <josh@joshtriplett.org>
> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>

Reviewed-by: Josh Triplett <josh@joshtriplett.org>

> kernel/notifier.c | 22 +++++++++++++---------
> 1 file changed, 13 insertions(+), 9 deletions(-)
>
> diff --git a/kernel/notifier.c b/kernel/notifier.c
> index db4c8b0..4803da6 100644
> --- a/kernel/notifier.c
> +++ b/kernel/notifier.c
> @@ -71,9 +71,9 @@ static int notifier_chain_unregister(struct notifier_block **nl,
> * @returns: notifier_call_chain returns the value returned by the
> * last notifier function called.
> */
> -static int __kprobes notifier_call_chain(struct notifier_block **nl,
> - unsigned long val, void *v,
> - int nr_to_call, int *nr_calls)
> +static int notifier_call_chain(struct notifier_block **nl,
> + unsigned long val, void *v,
> + int nr_to_call, int *nr_calls)
> {
> int ret = NOTIFY_DONE;
> struct notifier_block *nb, *next_nb;
> @@ -102,6 +102,7 @@ static int __kprobes notifier_call_chain(struct notifier_block **nl,
> }
> return ret;
> }
> +NOKPROBE_SYMBOL(notifier_call_chain);
>
> /*
> * Atomic notifier chain routines. Registration and unregistration
> @@ -172,9 +173,9 @@ EXPORT_SYMBOL_GPL(atomic_notifier_chain_unregister);
> * Otherwise the return value is the return value
> * of the last notifier function called.
> */
> -int __kprobes __atomic_notifier_call_chain(struct atomic_notifier_head *nh,
> - unsigned long val, void *v,
> - int nr_to_call, int *nr_calls)
> +int __atomic_notifier_call_chain(struct atomic_notifier_head *nh,
> + unsigned long val, void *v,
> + int nr_to_call, int *nr_calls)
> {
> int ret;
>
> @@ -184,13 +185,15 @@ int __kprobes __atomic_notifier_call_chain(struct atomic_notifier_head *nh,
> return ret;
> }
> EXPORT_SYMBOL_GPL(__atomic_notifier_call_chain);
> +NOKPROBE_SYMBOL(__atomic_notifier_call_chain);
>
> -int __kprobes atomic_notifier_call_chain(struct atomic_notifier_head *nh,
> - unsigned long val, void *v)
> +int atomic_notifier_call_chain(struct atomic_notifier_head *nh,
> + unsigned long val, void *v)
> {
> return __atomic_notifier_call_chain(nh, val, v, -1, NULL);
> }
> EXPORT_SYMBOL_GPL(atomic_notifier_call_chain);
> +NOKPROBE_SYMBOL(atomic_notifier_call_chain);
>
> /*
> * Blocking notifier chain routines. All access to the chain is
> @@ -527,7 +530,7 @@ EXPORT_SYMBOL_GPL(srcu_init_notifier_head);
>
> static ATOMIC_NOTIFIER_HEAD(die_chain);
>
> -int notrace __kprobes notify_die(enum die_val val, const char *str,
> +int notrace notify_die(enum die_val val, const char *str,
> struct pt_regs *regs, long err, int trap, int sig)
> {
> struct die_args args = {
> @@ -540,6 +543,7 @@ int notrace __kprobes notify_die(enum die_val val, const char *str,
> };
> return atomic_notifier_call_chain(&die_chain, val, &args);
> }
> +NOKPROBE_SYMBOL(notify_die);
>
> int register_die_notifier(struct notifier_block *nb)
> {
>
>