Update Linux to v5.4.148
Sourced from [1]
[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.4.148.tar.gz
Change-Id: Ib3d26c5ba9b022e2e03533005c4fed4d7c30b61b
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/kernel/signal.c b/kernel/signal.c
index bcd46f5..8c97fc7 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -391,16 +391,17 @@
void task_join_group_stop(struct task_struct *task)
{
+ unsigned long mask = current->jobctl & JOBCTL_STOP_SIGMASK;
+ struct signal_struct *sig = current->signal;
+
+ if (sig->group_stop_count) {
+ sig->group_stop_count++;
+ mask |= JOBCTL_STOP_CONSUME;
+ } else if (!(sig->flags & SIGNAL_STOP_STOPPED))
+ return;
+
/* Have the new thread join an on-going signal group stop */
- unsigned long jobctl = current->jobctl;
- if (jobctl & JOBCTL_STOP_PENDING) {
- struct signal_struct *sig = current->signal;
- unsigned long signr = jobctl & JOBCTL_STOP_SIGMASK;
- unsigned long gstop = JOBCTL_STOP_PENDING | JOBCTL_STOP_CONSUME;
- if (task_set_jobctl_pending(task, signr | gstop)) {
- sig->group_stop_count++;
- }
- }
+ task_set_jobctl_pending(task, mask | JOBCTL_STOP_PENDING);
}
/*
@@ -413,27 +414,32 @@
{
struct sigqueue *q = NULL;
struct user_struct *user;
+ int sigpending;
/*
* Protect access to @t credentials. This can go away when all
* callers hold rcu read lock.
+ *
+ * NOTE! A pending signal will hold on to the user refcount,
+ * and we get/put the refcount only when the sigpending count
+ * changes from/to zero.
*/
rcu_read_lock();
- user = get_uid(__task_cred(t)->user);
- atomic_inc(&user->sigpending);
+ user = __task_cred(t)->user;
+ sigpending = atomic_inc_return(&user->sigpending);
+ if (sigpending == 1)
+ get_uid(user);
rcu_read_unlock();
- if (override_rlimit ||
- atomic_read(&user->sigpending) <=
- task_rlimit(t, RLIMIT_SIGPENDING)) {
+ if (override_rlimit || likely(sigpending <= task_rlimit(t, RLIMIT_SIGPENDING))) {
q = kmem_cache_alloc(sigqueue_cachep, flags);
} else {
print_dropped_signal(sig);
}
if (unlikely(q == NULL)) {
- atomic_dec(&user->sigpending);
- free_uid(user);
+ if (atomic_dec_and_test(&user->sigpending))
+ free_uid(user);
} else {
INIT_LIST_HEAD(&q->list);
q->flags = 0;
@@ -447,8 +453,8 @@
{
if (q->flags & SIGQUEUE_PREALLOC)
return;
- atomic_dec(&q->user->sigpending);
- free_uid(q->user);
+ if (atomic_dec_and_test(&q->user->sigpending))
+ free_uid(q->user);
kmem_cache_free(sigqueue_cachep, q);
}
@@ -1505,15 +1511,15 @@
unsigned long flags;
int ret = -EINVAL;
+ if (!valid_signal(sig))
+ return ret;
+
clear_siginfo(&info);
info.si_signo = sig;
info.si_errno = errno;
info.si_code = SI_ASYNCIO;
*((sigval_t *)&info.si_pid) = addr;
- if (!valid_signal(sig))
- return ret;
-
rcu_read_lock();
p = pid_task(pid, PIDTYPE_PID);
if (!p) {
@@ -1926,7 +1932,7 @@
* This is only possible if parent == real_parent.
* Check if it has changed security domain.
*/
- if (tsk->parent_exec_id != tsk->parent->self_exec_id)
+ if (tsk->parent_exec_id != READ_ONCE(tsk->parent->self_exec_id))
sig = SIGCHLD;
}
@@ -1988,8 +1994,12 @@
if (psig->action[SIGCHLD-1].sa.sa_handler == SIG_IGN)
sig = 0;
}
+ /*
+ * Send with __send_signal as si_pid and si_uid are in the
+ * parent's namespaces.
+ */
if (valid_signal(sig) && sig)
- __group_send_sig_info(sig, &info, tsk->parent);
+ __send_signal(sig, &info, tsk->parent, PIDTYPE_TGID, false);
__wake_up_parent(tsk, tsk->parent);
spin_unlock_irqrestore(&psig->siglock, flags);