[PATCH -mm 4/7][AIO] Resend - Make good_sigevent() non-static

Sébastien Dugué
2007-02-05T12:19:55Z

Andrew,

Could you replace make-good_sigevent-non-static.patch with this
patch, as it fixes some problems reported by Oleg Nesterov.

Oleg, chime in if you still see something I missed.

Hopefully I will have gotten it right this time.

Sorry for the hassle.

Sébastien.

From: Sébastien Dugué <sebastien.dugue@bull.net>

Make good_sigevent() non-static and rename it

Move good_sigevent() from posix-timers.c to signal.c where it belongs,
clean it up, rename it to sigevent_find_task() to better describe what the
function does and make it non-static so that it can be used by other
subsystems.

include/linux/signal.h | 1 +
kernel/posix-timers.c | 19 +------------------
kernel/signal.c | 24 ++++++++++++++++++++++++
3 files changed, 26 insertions(+), 18 deletions(-)

Signed-off-by: Sébastien Dugué <sebastien.dugue@bull.net>

Index: linux-2.6.20-rc6-mm3/include/linux/signal.h
===================================================================
--- linux-2.6.20-rc6-mm3.orig/include/linux/signal.h 2007-01-30 11:41:27.000000000 +0100
+++ linux-2.6.20-rc6-mm3/include/linux/signal.h 2007-02-05 12:25:12.000000000 +0100
@@ -240,6 +240,7 @@ extern int sigprocmask(int, sigset_t *,

struct pt_regs;
extern int get_signal_to_deliver(siginfo_t *info, struct k_sigaction *return_ka, struct pt_regs *regs, void *cookie);
+extern struct task_struct * sigevent_find_task(sigevent_t *);

extern struct kmem_cache *sighand_cachep;

Index: linux-2.6.20-rc6-mm3/kernel/posix-timers.c
===================================================================
--- linux-2.6.20-rc6-mm3.orig/kernel/posix-timers.c 2007-01-30 11:41:27.000000000 +0100
+++ linux-2.6.20-rc6-mm3/kernel/posix-timers.c 2007-01-30 11:41:36.000000000 +0100
@@ -367,23 +367,6 @@ static enum hrtimer_restart posix_timer_
return ret;
}

-static struct task_struct * good_sigevent(sigevent_t * event)
-{
- struct task_struct *rtn = current->group_leader;
-
- if ((event->sigev_notify & SIGEV_THREAD_ID ) &&
- (!(rtn = find_task_by_pid(event->sigev_notify_thread_id)) ||
- rtn->tgid != current->tgid ||
- (event->sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_SIGNAL))
- return NULL;
-
- if (((event->sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE) &&
- ((event->sigev_signo <= 0) || (event->sigev_signo > SIGRTMAX)))
- return NULL;
-
- return rtn;
-}
-
void register_posix_clock(const clockid_t clock_id, struct k_clock *new_clock)
{
if ((unsigned) clock_id >= MAX_CLOCKS) {
@@ -496,7 +479,7 @@ sys_timer_create(const clockid_t which_c
new_timer->it_sigev_value = event.sigev_value;

read_lock(&tasklist_lock);
- if ((process = good_sigevent(&event))) {
+ if ((process = sigevent_find_task(&event))) {
/*
* We may be setting up this process for another
* thread. It may be exiting. To catch this
Index: linux-2.6.20-rc6-mm3/kernel/signal.c
===================================================================
--- linux-2.6.20-rc6-mm3.orig/kernel/signal.c 2007-01-30 11:41:27.000000000 +0100
+++ linux-2.6.20-rc6-mm3/kernel/signal.c 2007-02-05 12:27:33.000000000 +0100
@@ -1213,6 +1213,34 @@ int group_send_sig_info(int sig, struct
return ret;
}

+/***
+ * sigevent_find_task - check and get target task from a sigevent.
+ * @event: the sigevent to be checked
+ *
+ * This function must be called with the tasklist_lock held for reading.
+ */
+struct task_struct * sigevent_find_task(sigevent_t * event)
+{
+ struct task_struct *task = current->group_leader;
+
+ if ((event->sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE) {
+ if (event->sigev_signo <= 0 || event->sigev_signo > SIGRTMAX)
+ return NULL;
+ }
+
+ if (event->sigev_notify & SIGEV_THREAD_ID) {
+ if ((event->sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_SIGNAL)
+ return NULL;
+
+ task = find_task_by_pid(event->sigev_notify_thread_id);
+
+ if (!task || task->tgid != current->tgid)
+ task = NULL;
+ }
+
+ return task;
+}
+
/*
* kill_pgrp_info() sends a signal to a process group: this is what the tty
* control characters do (^C, ^Z etc)