We protect 64bit sum_exec_runtime variable against inconsistency on 32 bit architectures when reading it on thread_group_cputime(), but we also read it on other places not protected.
Patch changes that, except file kernel/sched/debug.c , where we also read some other u64 variables (vruntime, exec_start) without protection. But since this is for debug purpose and inconsistency is very unlike, we can ignore that. Signed-off-by: Stanislaw Gruszka <[email protected]> --- fs/proc/base.c | 2 +- include/linux/sched.h | 19 +++++++++++++++++++ kernel/delayacct.c | 2 +- kernel/exit.c | 2 +- kernel/sched/cputime.c | 21 +-------------------- kernel/time/posix-cpu-timers.c | 4 ++-- 6 files changed, 25 insertions(+), 25 deletions(-) diff --git a/fs/proc/base.c b/fs/proc/base.c index e9ff186..8118d97 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -505,7 +505,7 @@ static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns, seq_printf(m, "0 0 0\n"); else seq_printf(m, "%llu %llu %lu\n", - (unsigned long long)task->se.sum_exec_runtime, + (unsigned long long)read_sum_exec_runtime(task), (unsigned long long)task->sched_info.run_delay, task->sched_info.pcount); diff --git a/include/linux/sched.h b/include/linux/sched.h index eb64fcd..267fc98 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -2508,6 +2508,25 @@ static inline void disable_sched_clock_irqtime(void) {} extern unsigned long long task_sched_runtime(struct task_struct *task); +#ifdef CONFIG_64BIT +static inline u64 read_sum_exec_runtime(struct task_struct *t) +{ + return t->se.sum_exec_runtime; +} +#else +static inline u64 read_sum_exec_runtime(struct task_struct *t) +{ + u64 ns; + unsigned long flags; + + raw_spin_lock_irqsave(&t->pi_lock, flags); + ns = t->se.sum_exec_runtime; + raw_spin_unlock_irqrestore(&t->pi_lock, flags); + + return ns; +} +#endif + /* sched_exec is called by processes performing an exec */ #ifdef CONFIG_SMP extern void sched_exec(void); diff --git a/kernel/delayacct.c b/kernel/delayacct.c index 435c14a..023b2ca 100644 --- a/kernel/delayacct.c +++ b/kernel/delayacct.c @@ -104,7 +104,7 @@ int __delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk) */ t1 = tsk->sched_info.pcount; t2 = tsk->sched_info.run_delay; - t3 = tsk->se.sum_exec_runtime; + t3 = read_sum_exec_runtime(tsk); d->cpu_count += t1; diff --git a/kernel/exit.c b/kernel/exit.c index 2f974ae..a46f96f 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -134,7 +134,7 @@ static void __exit_signal(struct task_struct *tsk) sig->inblock += task_io_get_inblock(tsk); sig->oublock += task_io_get_oublock(tsk); task_io_accounting_add(&sig->ioac, &tsk->ioac); - sig->sum_sched_runtime += tsk->se.sum_exec_runtime; + sig->sum_sched_runtime += read_sum_exec_runtime(tsk); sig->nr_threads--; __unhash_process(tsk, group_dead); write_sequnlock(&sig->stats_lock); diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c index 5535774..4d080f2 100644 --- a/kernel/sched/cputime.c +++ b/kernel/sched/cputime.c @@ -306,25 +306,6 @@ static inline cputime_t account_other_time(cputime_t max) return accounted; } -#ifdef CONFIG_64BIT -static inline u64 read_sum_exec_runtime(struct task_struct *t) -{ - return t->se.sum_exec_runtime; -} -#else -static u64 read_sum_exec_runtime(struct task_struct *t) -{ - u64 ns; - unsigned long flags; - - raw_spin_lock_irqsave(&t->pi_lock, flags); - ns = t->se.sum_exec_runtime; - raw_spin_unlock_irqrestore(&t->pi_lock, flags); - - return ns; -} -#endif - /* * Accumulate raw cputime values of dead tasks (sig->[us]time) and live * tasks (sum on group iteration) belonging to @tsk's group. @@ -701,7 +682,7 @@ out: void task_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st) { struct task_cputime cputime = { - .sum_exec_runtime = p->se.sum_exec_runtime, + .sum_exec_runtime = read_sum_exec_runtime(p), }; task_cputime(p, &cputime.utime, &cputime.stime); diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c index 39008d7..a2d753b 100644 --- a/kernel/time/posix-cpu-timers.c +++ b/kernel/time/posix-cpu-timers.c @@ -848,7 +848,7 @@ static void check_thread_timers(struct task_struct *tsk, tsk_expires->virt_exp = expires_to_cputime(expires); tsk_expires->sched_exp = check_timers_list(++timers, firing, - tsk->se.sum_exec_runtime); + read_sum_exec_runtime(tsk)); /* * Check for the special case thread timers. @@ -1115,7 +1115,7 @@ static inline int fastpath_timer_check(struct task_struct *tsk) struct task_cputime task_sample; task_cputime(tsk, &task_sample.utime, &task_sample.stime); - task_sample.sum_exec_runtime = tsk->se.sum_exec_runtime; + task_sample.sum_exec_runtime = read_sum_exec_runtime(tsk); if (task_cputime_expired(&task_sample, &tsk->cputime_expires)) return 1; } -- 1.8.3.1
