[GIT pull] timers/urgent for 5.7-rc1

From: Thomas Gleixner
Date: Sun Apr 05 2020 - 09:43:15 EST


Linus,

please pull the latest timers/urgent branch from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git timers-urgent-2020-04-05

up to: 760a53768610: clocksource/drivers/timer-vf-pit: Add missing parenthesis


Two timer subsystem fixes:

- Prevent a use after free in the new lockdep state tracking for hrtimers

- Add missing parenthesis in the VF pit timer driver

Thanks,

tglx

------------------>
Sebastian Andrzej Siewior (1):
hrtimer: Don't dereference the hrtimer pointer after the callback

afzal mohammed (1):
clocksource/drivers/timer-vf-pit: Add missing parenthesis


drivers/clocksource/timer-vf-pit.c | 2 +-
include/linux/irqflags.h | 27 ++++++++++++++++-----------
kernel/time/hrtimer.c | 5 +++--
3 files changed, 20 insertions(+), 14 deletions(-)

diff --git a/drivers/clocksource/timer-vf-pit.c b/drivers/clocksource/timer-vf-pit.c
index 7ad4a8b008c2..1a86a4e7e344 100644
--- a/drivers/clocksource/timer-vf-pit.c
+++ b/drivers/clocksource/timer-vf-pit.c
@@ -129,7 +129,7 @@ static int __init pit_clockevent_init(unsigned long rate, int irq)
__raw_writel(PITTFLG_TIF, clkevt_base + PITTFLG);

BUG_ON(request_irq(irq, pit_timer_interrupt, IRQF_TIMER | IRQF_IRQPOLL,
- "VF pit timer", &clockevent_pit);
+ "VF pit timer", &clockevent_pit));

clockevent_pit.cpumask = cpumask_of(0);
clockevent_pit.irq = irq;
diff --git a/include/linux/irqflags.h b/include/linux/irqflags.h
index ceca42de4438..61a9ced3aa50 100644
--- a/include/linux/irqflags.h
+++ b/include/linux/irqflags.h
@@ -58,16 +58,21 @@ do { \
} while (0)

# define lockdep_hrtimer_enter(__hrtimer) \
- do { \
- if (!__hrtimer->is_hard) \
- current->irq_config = 1; \
- } while (0)
-
-# define lockdep_hrtimer_exit(__hrtimer) \
- do { \
- if (!__hrtimer->is_hard) \
+({ \
+ bool __expires_hardirq = true; \
+ \
+ if (!__hrtimer->is_hard) { \
+ current->irq_config = 1; \
+ __expires_hardirq = false; \
+ } \
+ __expires_hardirq; \
+})
+
+# define lockdep_hrtimer_exit(__expires_hardirq) \
+ do { \
+ if (!__expires_hardirq) \
current->irq_config = 0; \
- } while (0)
+ } while (0)

# define lockdep_posixtimer_enter() \
do { \
@@ -102,8 +107,8 @@ do { \
# define lockdep_hardirq_exit() do { } while (0)
# define lockdep_softirq_enter() do { } while (0)
# define lockdep_softirq_exit() do { } while (0)
-# define lockdep_hrtimer_enter(__hrtimer) do { } while (0)
-# define lockdep_hrtimer_exit(__hrtimer) do { } while (0)
+# define lockdep_hrtimer_enter(__hrtimer) false
+# define lockdep_hrtimer_exit(__context) do { } while (0)
# define lockdep_posixtimer_enter() do { } while (0)
# define lockdep_posixtimer_exit() do { } while (0)
# define lockdep_irq_work_enter(__work) do { } while (0)
diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
index d0a5ba37aff4..d89da1c7e005 100644
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c
@@ -1480,6 +1480,7 @@ static void __run_hrtimer(struct hrtimer_cpu_base *cpu_base,
unsigned long flags) __must_hold(&cpu_base->lock)
{
enum hrtimer_restart (*fn)(struct hrtimer *);
+ bool expires_in_hardirq;
int restart;

lockdep_assert_held(&cpu_base->lock);
@@ -1514,11 +1515,11 @@ static void __run_hrtimer(struct hrtimer_cpu_base *cpu_base,
*/
raw_spin_unlock_irqrestore(&cpu_base->lock, flags);
trace_hrtimer_expire_entry(timer, now);
- lockdep_hrtimer_enter(timer);
+ expires_in_hardirq = lockdep_hrtimer_enter(timer);

restart = fn(timer);

- lockdep_hrtimer_exit(timer);
+ lockdep_hrtimer_exit(expires_in_hardirq);
trace_hrtimer_expire_exit(timer);
raw_spin_lock_irq(&cpu_base->lock);