[patch V5 20/26] signal: Provide ignored_posix_timers list

From: Thomas Gleixner
Date: Tue Oct 01 2024 - 04:46:24 EST


From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>

To prepare for handling posix timer signals on sigaction(SIG_IGN) properly,
add a list to task::signal.

This list will be used to queue posix timers so their signal can be
requeued when SIG_IGN is lifted later.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
---
include/linux/sched/signal.h | 1 +
init/init_task.c | 5 +++--
kernel/fork.c | 1 +
3 files changed, 5 insertions(+), 2 deletions(-)
---
--- a/include/linux/sched/signal.h
+++ b/include/linux/sched/signal.h
@@ -138,6 +138,7 @@ struct signal_struct {
/* POSIX.1b Interval Timers */
unsigned int next_posix_timer_id;
struct hlist_head posix_timers;
+ struct hlist_head ignored_posix_timers;

/* ITIMER_REAL timer for the process */
struct hrtimer real_timer;
--- a/init/init_task.c
+++ b/init/init_task.c
@@ -30,8 +30,9 @@ static struct signal_struct init_signals
.cred_guard_mutex = __MUTEX_INITIALIZER(init_signals.cred_guard_mutex),
.exec_update_lock = __RWSEM_INITIALIZER(init_signals.exec_update_lock),
#ifdef CONFIG_POSIX_TIMERS
- .posix_timers = HLIST_HEAD_INIT,
- .cputimer = {
+ .posix_timers = HLIST_HEAD_INIT,
+ .ignored_posix_timers = HLIST_HEAD_INIT,
+ .cputimer = {
.cputime_atomic = INIT_CPUTIME_ATOMIC,
},
#endif
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1864,6 +1864,7 @@ static int copy_signal(unsigned long clo

#ifdef CONFIG_POSIX_TIMERS
INIT_HLIST_HEAD(&sig->posix_timers);
+ INIT_HLIST_HEAD(&sig->ignored_posix_timers);
hrtimer_init(&sig->real_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
sig->real_timer.function = it_real_fn;
#endif