From: Roland McGrath <roland@redhat.com>
After my last change, there are plenty of unused bits available in the new
flags word in signal_struct. This patch moves the `group_exit' flag into
one of those bits, saving a word in signal_struct.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/fs/exec.c | 7 +++----
25-akpm/include/linux/sched.h | 2 +-
25-akpm/kernel/exit.c | 10 +++++-----
25-akpm/kernel/fork.c | 3 +--
25-akpm/kernel/signal.c | 15 ++++++++++-----
5 files changed, 20 insertions(+), 17 deletions(-)
diff -puN fs/exec.c~move-group_exit-flag-into-signal_structflags-word fs/exec.c
--- 25/fs/exec.c~move-group_exit-flag-into-signal_structflags-word 2004-12-03 20:56:02.685351952 -0800
+++ 25-akpm/fs/exec.c 2004-12-03 20:56:02.695350432 -0800
@@ -600,7 +600,7 @@ static inline int de_thread(struct task_
*/
read_lock(&tasklist_lock);
spin_lock_irq(lock);
- if (sig->group_exit) {
+ if (sig->flags & SIGNAL_GROUP_EXIT) {
/*
* Another group action in progress, just
* return so that the signal is processed.
@@ -610,7 +610,6 @@ static inline int de_thread(struct task_
kmem_cache_free(sighand_cachep, newsighand);
return -EAGAIN;
}
- sig->group_exit = 1;
zap_other_threads(current);
read_unlock(&tasklist_lock);
@@ -708,7 +707,7 @@ static inline int de_thread(struct task_
* Now there are really no other threads at all,
* so it's safe to stop telling them to kill themselves.
*/
- sig->group_exit = 0;
+ sig->flags = 0;
no_thread_group:
BUG_ON(atomic_read(&sig->count) != 1);
@@ -1393,7 +1392,7 @@ int do_coredump(long signr, int exit_cod
}
mm->dumpable = 0;
init_completion(&mm->core_done);
- current->signal->group_exit = 1;
+ current->signal->flags = SIGNAL_GROUP_EXIT;
current->signal->group_exit_code = exit_code;
coredump_wait(mm);
diff -puN include/linux/sched.h~move-group_exit-flag-into-signal_structflags-word include/linux/sched.h
--- 25/include/linux/sched.h~move-group_exit-flag-into-signal_structflags-word 2004-12-03 20:56:02.687351648 -0800
+++ 25-akpm/include/linux/sched.h 2004-12-03 20:56:02.697350128 -0800
@@ -282,7 +282,6 @@ struct signal_struct {
struct sigpending shared_pending;
/* thread group exit support */
- int group_exit;
int group_exit_code;
/* overloaded:
* - notify group_exit_task when ->count is equal to notify_count
@@ -336,6 +335,7 @@ struct signal_struct {
#define SIGNAL_STOP_STOPPED 0x00000001 /* job control stop in effect */
#define SIGNAL_STOP_DEQUEUED 0x00000002 /* stop signal dequeued */
#define SIGNAL_STOP_CONTINUED 0x00000004 /* SIGCONT since WCONTINUED reap */
+#define SIGNAL_GROUP_EXIT 0x00000008 /* group exit in progress */
/*
diff -puN kernel/exit.c~move-group_exit-flag-into-signal_structflags-word kernel/exit.c
--- 25/kernel/exit.c~move-group_exit-flag-into-signal_structflags-word 2004-12-03 20:56:02.688351496 -0800
+++ 25-akpm/kernel/exit.c 2004-12-03 20:56:02.698349976 -0800
@@ -657,7 +657,7 @@ static void exit_notify(struct task_stru
struct task_struct *t;
struct list_head ptrace_dead, *_p, *_n;
- if (signal_pending(tsk) && !tsk->signal->group_exit
+ if (signal_pending(tsk) && !(tsk->signal->flags & SIGNAL_GROUP_EXIT)
&& !thread_group_empty(tsk)) {
/*
* This occurs when there was a race between our exit
@@ -880,18 +880,18 @@ do_group_exit(int exit_code)
{
BUG_ON(exit_code & 0x80); /* core dumps don't get here */
- if (current->signal->group_exit)
+ if (current->signal->flags & SIGNAL_GROUP_EXIT)
exit_code = current->signal->group_exit_code;
else if (!thread_group_empty(current)) {
struct signal_struct *const sig = current->signal;
struct sighand_struct *const sighand = current->sighand;
read_lock(&tasklist_lock);
spin_lock_irq(&sighand->siglock);
- if (sig->group_exit)
+ if (sig->flags & SIGNAL_GROUP_EXIT)
/* Another thread got here before we took the lock. */
exit_code = sig->group_exit_code;
else {
- sig->group_exit = 1;
+ sig->flags = SIGNAL_GROUP_EXIT;
sig->group_exit_code = exit_code;
zap_other_threads(current);
}
@@ -1071,7 +1071,7 @@ static int wait_task_zombie(task_t *p, i
read_unlock(&tasklist_lock);
retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0;
- status = p->signal->group_exit
+ status = (p->signal->flags & SIGNAL_GROUP_EXIT)
? p->signal->group_exit_code : p->exit_code;
if (!retval && stat_addr)
retval = put_user(status, stat_addr);
diff -puN kernel/fork.c~move-group_exit-flag-into-signal_structflags-word kernel/fork.c
--- 25/kernel/fork.c~move-group_exit-flag-into-signal_structflags-word 2004-12-03 20:56:02.690351192 -0800
+++ 25-akpm/kernel/fork.c 2004-12-03 20:56:02.699349824 -0800
@@ -734,7 +734,6 @@ static inline int copy_signal(unsigned l
atomic_set(&sig->count, 1);
atomic_set(&sig->live, 1);
sig->flags = 0;
- sig->group_exit = 0;
sig->group_exit_code = 0;
sig->group_exit_task = NULL;
sig->group_stop_count = 0;
@@ -1000,7 +999,7 @@ static task_t *copy_process(unsigned lon
* do not create this new thread - the whole thread
* group is supposed to exit anyway.
*/
- if (current->signal->group_exit) {
+ if (current->signal->flags & SIGNAL_GROUP_EXIT) {
spin_unlock(¤t->sighand->siglock);
write_unlock_irq(&tasklist_lock);
retval = -EAGAIN;
diff -puN kernel/signal.c~move-group_exit-flag-into-signal_structflags-word kernel/signal.c
--- 25/kernel/signal.c~move-group_exit-flag-into-signal_structflags-word 2004-12-03 20:56:02.692350888 -0800
+++ 25-akpm/kernel/signal.c 2004-12-03 20:56:02.701349520 -0800
@@ -661,6 +661,12 @@ static void handle_stop_signal(int sig,
{
struct task_struct *t;
+ if (p->flags & SIGNAL_GROUP_EXIT)
+ /*
+ * The process is in the middle of dying already.
+ */
+ return;
+
if (sig_kernel_stop(sig)) {
/*
* This is a stop signal. Remove SIGCONT from all queues.
@@ -976,7 +982,7 @@ __group_complete_signal(int sig, struct
* Found a killable thread. If the signal will be fatal,
* then start taking the whole group down immediately.
*/
- if (sig_fatal(p, sig) && !p->signal->group_exit &&
+ if (sig_fatal(p, sig) && !(p->signal->flags & SIGNAL_GROUP_EXIT) &&
!sigismember(&t->real_blocked, sig) &&
(sig == SIGKILL || !(t->ptrace & PT_PTRACED))) {
/*
@@ -989,10 +995,9 @@ __group_complete_signal(int sig, struct
* running and doing things after a slower
* thread has the fatal signal pending.
*/
- p->signal->group_exit = 1;
+ p->signal->flags = SIGNAL_GROUP_EXIT;
p->signal->group_exit_code = sig;
p->signal->group_stop_count = 0;
- p->signal->flags = 0;
t = p;
do {
sigaddset(&t->pending.signal, SIGKILL);
@@ -1079,8 +1084,8 @@ void zap_other_threads(struct task_struc
{
struct task_struct *t;
+ p->signal->flags = SIGNAL_GROUP_EXIT;
p->signal->group_stop_count = 0;
- p->signal->flags = 0;
if (thread_group_empty(p))
return;
@@ -1785,7 +1790,7 @@ static inline int handle_group_stop(void
return 0;
}
- if (current->signal->group_exit)
+ if (current->signal->flags & SIGNAL_GROUP_EXIT)
/*
* Group stop is so another thread can do a core dump,
* or else we are racing against a death signal.
_