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Diffstat (limited to 'kernel/fork.c')
-rw-r--r--kernel/fork.c91
1 files changed, 70 insertions, 21 deletions
diff --git a/kernel/fork.c b/kernel/fork.c
index 4fc3fcd5dacb..9e12b35e3924 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -665,22 +665,39 @@ out_release:
static inline int copy_sighand(unsigned long clone_flags, struct task_struct * tsk)
{
- struct signal_struct *sig;
+ struct sighand_struct *sig;
- if (clone_flags & CLONE_SIGHAND) {
- atomic_inc(&current->sig->count);
+ if (clone_flags & (CLONE_SIGHAND | CLONE_THREAD)) {
+ atomic_inc(&current->sighand->count);
return 0;
}
- sig = kmem_cache_alloc(sigact_cachep, GFP_KERNEL);
- tsk->sig = sig;
+ sig = kmem_cache_alloc(sighand_cachep, GFP_KERNEL);
+ tsk->sighand = sig;
if (!sig)
return -1;
spin_lock_init(&sig->siglock);
atomic_set(&sig->count, 1);
+ memcpy(sig->action, current->sighand->action, sizeof(sig->action));
+ return 0;
+}
+
+static inline int copy_signal(unsigned long clone_flags, struct task_struct * tsk)
+{
+ struct signal_struct *sig;
+
+ if (clone_flags & CLONE_THREAD) {
+ atomic_inc(&current->signal->count);
+ return 0;
+ }
+ sig = kmem_cache_alloc(signal_cachep, GFP_KERNEL);
+ tsk->signal = sig;
+ if (!sig)
+ return -1;
+ atomic_set(&sig->count, 1);
sig->group_exit = 0;
sig->group_exit_code = 0;
sig->group_exit_task = NULL;
- memcpy(sig->action, current->sig->action, sizeof(sig->action));
+ sig->group_stop_count = 0;
sig->curr_target = NULL;
init_sigpending(&sig->shared_pending);
@@ -801,7 +818,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
spin_lock_init(&p->alloc_lock);
spin_lock_init(&p->switch_lock);
- clear_tsk_thread_flag(p,TIF_SIGPENDING);
+ clear_tsk_thread_flag(p, TIF_SIGPENDING);
init_sigpending(&p->pending);
p->it_real_value = p->it_virt_value = p->it_prof_value = 0;
@@ -830,8 +847,10 @@ static struct task_struct *copy_process(unsigned long clone_flags,
goto bad_fork_cleanup_files;
if (copy_sighand(clone_flags, p))
goto bad_fork_cleanup_fs;
- if (copy_mm(clone_flags, p))
+ if (copy_signal(clone_flags, p))
goto bad_fork_cleanup_sighand;
+ if (copy_mm(clone_flags, p))
+ goto bad_fork_cleanup_signal;
if (copy_namespace(clone_flags, p))
goto bad_fork_cleanup_mm;
retval = copy_thread(0, clone_flags, stack_start, stack_size, p, regs);
@@ -910,6 +929,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
*/
if (sigismember(&current->pending.signal, SIGKILL)) {
write_unlock_irq(&tasklist_lock);
+ retval = -EINTR;
goto bad_fork_cleanup_namespace;
}
@@ -921,20 +941,31 @@ static struct task_struct *copy_process(unsigned long clone_flags,
p->parent = p->real_parent;
if (clone_flags & CLONE_THREAD) {
- spin_lock(&current->sig->siglock);
+ spin_lock(&current->sighand->siglock);
/*
* Important: if an exit-all has been started then
* do not create this new thread - the whole thread
* group is supposed to exit anyway.
*/
- if (current->sig->group_exit) {
- spin_unlock(&current->sig->siglock);
+ if (current->signal->group_exit) {
+ spin_unlock(&current->sighand->siglock);
write_unlock_irq(&tasklist_lock);
goto bad_fork_cleanup_namespace;
}
p->tgid = current->tgid;
p->group_leader = current->group_leader;
- spin_unlock(&current->sig->siglock);
+
+ if (current->signal->group_stop_count > 0) {
+ /*
+ * There is an all-stop in progress for the group.
+ * We ourselves will stop as soon as we check signals.
+ * Make the new thread part of that group stop too.
+ */
+ current->signal->group_stop_count++;
+ set_tsk_thread_flag(p, TIF_SIGPENDING);
+ }
+
+ spin_unlock(&current->sighand->siglock);
}
SET_LINKS(p);
@@ -964,6 +995,8 @@ bad_fork_cleanup_namespace:
exit_namespace(p);
bad_fork_cleanup_mm:
exit_mm(p);
+bad_fork_cleanup_signal:
+ exit_signal(p);
bad_fork_cleanup_sighand:
exit_sighand(p);
bad_fork_cleanup_fs:
@@ -1036,8 +1069,13 @@ struct task_struct *do_fork(unsigned long clone_flags,
init_completion(&vfork);
}
- if (p->ptrace & PT_PTRACED)
- send_sig(SIGSTOP, p, 1);
+ if (p->ptrace & PT_PTRACED) {
+ /*
+ * We'll start up with an immediate SIGSTOP.
+ */
+ sigaddset(&p->pending.signal, SIGSTOP);
+ set_tsk_thread_flag(p, TIF_SIGPENDING);
+ }
wake_up_forked_process(p); /* do this last */
++total_forks;
@@ -1047,9 +1085,11 @@ struct task_struct *do_fork(unsigned long clone_flags,
ptrace_notify ((trace << 8) | SIGTRAP);
}
- if (clone_flags & CLONE_VFORK)
+ if (clone_flags & CLONE_VFORK) {
wait_for_completion(&vfork);
- else
+ if (unlikely (current->ptrace & PT_TRACE_VFORK_DONE))
+ ptrace_notify ((PTRACE_EVENT_VFORK_DONE << 8) | SIGTRAP);
+ } else
/*
* Let the child process run first, to avoid most of the
* COW overhead when the child exec()s afterwards.
@@ -1059,8 +1099,11 @@ struct task_struct *do_fork(unsigned long clone_flags,
return p;
}
-/* SLAB cache for signal_struct structures (tsk->sig) */
-kmem_cache_t *sigact_cachep;
+/* SLAB cache for signal_struct structures (tsk->signal) */
+kmem_cache_t *signal_cachep;
+
+/* SLAB cache for sighand_struct structures (tsk->sighand) */
+kmem_cache_t *sighand_cachep;
/* SLAB cache for files_struct structures (tsk->files) */
kmem_cache_t *files_cachep;
@@ -1076,11 +1119,17 @@ kmem_cache_t *mm_cachep;
void __init proc_caches_init(void)
{
- sigact_cachep = kmem_cache_create("signal_act",
+ sighand_cachep = kmem_cache_create("sighand_cache",
+ sizeof(struct sighand_struct), 0,
+ SLAB_HWCACHE_ALIGN, NULL, NULL);
+ if (!sighand_cachep)
+ panic("Cannot create sighand SLAB cache");
+
+ signal_cachep = kmem_cache_create("signal_cache",
sizeof(struct signal_struct), 0,
SLAB_HWCACHE_ALIGN, NULL, NULL);
- if (!sigact_cachep)
- panic("Cannot create signal action SLAB cache");
+ if (!signal_cachep)
+ panic("Cannot create signal SLAB cache");
files_cachep = kmem_cache_create("files_cache",
sizeof(struct files_struct), 0,
generated by cgit v1.2.3 (git 2.46.0) at 2026-02-03 08:58:21 +0000