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

Pull timer fixes from Thomas Gleixner:
 "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"

* tag 'timers-urgent-2020-04-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  clocksource/drivers/timer-vf-pit: Add missing parenthesis
  hrtimer: Don't dereference the hrtimer pointer after the callback
This commit is contained in:
Linus Torvalds 2020-04-05 12:06:51 -07:00
commit d5ca32738f
3 changed files with 19 additions and 13 deletions

View File

@ -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;

View File

@ -58,16 +58,21 @@ do { \
} while (0)
# define lockdep_hrtimer_enter(__hrtimer) \
do { \
if (!__hrtimer->is_hard) \
current->irq_config = 1; \
} while (0)
({ \
bool __expires_hardirq = true; \
\
if (!__hrtimer->is_hard) { \
current->irq_config = 1; \
__expires_hardirq = false; \
} \
__expires_hardirq; \
})
# define lockdep_hrtimer_exit(__hrtimer) \
do { \
if (!__hrtimer->is_hard) \
# 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)

View File

@ -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);