From c0deae8c9587419ab13874b74425ce2eb2e18508 Mon Sep 17 00:00:00 2001 From: Sergey Senozhatsky Date: Wed, 3 Nov 2010 18:52:56 +0200 Subject: posix-cpu-timers: Rcu_read_lock/unlock protect find_task_by_vpid call Commit 4221a9918e38b7494cee341dda7b7b4bb8c04bde "Add RCU check for find_task_by_vpid()" introduced rcu_lockdep_assert to find_task_by_pid_ns. Add rcu_read_lock/rcu_read_unlock to call find_task_by_vpid. Tetsuo Handa wrote: | Quoting from one of posts in that thead | http://kerneltrap.org/mailarchive/linux-kernel/2010/2/8/4536388 | || Usually tasklist gives enough protection, but if copy_process() fails || it calls free_pid() lockless and does call_rcu(delayed_put_pid(). || This means, without rcu lock find_pid_ns() can't scan the hash table || safely. Thomas Gleixner wrote: | We can remove the tasklist_lock while at it. rcu_read_lock is enough. Patch also replaces thread_group_leader with has_group_leader_pid in accordance to comment by Oleg Nesterov: | ... thread_group_leader() check is not relaible without | tasklist. If we race with de_thread() find_task_by_vpid() can find | the new leader before it updates its ->group_leader. | | perhaps it makes sense to change posix_cpu_timer_create() to use | has_group_leader_pid() instead, just to make this code not look racy | and avoid adding new problems. Signed-off-by: Sergey Senozhatsky Cc: Peter Zijlstra Cc: Stanislaw Gruszka Reviewed-by: Oleg Nesterov LKML-Reference: <20101103165256.GD30053@swordfish.minsk.epam.com> Signed-off-by: Thomas Gleixner --- kernel/posix-cpu-timers.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'kernel/posix-cpu-timers.c') diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c index 6842eeba5879..05bb7173850e 100644 --- a/kernel/posix-cpu-timers.c +++ b/kernel/posix-cpu-timers.c @@ -37,13 +37,13 @@ static int check_clock(const clockid_t which_clock) if (pid == 0) return 0; - read_lock(&tasklist_lock); + rcu_read_lock(); p = find_task_by_vpid(pid); if (!p || !(CPUCLOCK_PERTHREAD(which_clock) ? - same_thread_group(p, current) : thread_group_leader(p))) { + same_thread_group(p, current) : has_group_leader_pid(p))) { error = -EINVAL; } - read_unlock(&tasklist_lock); + rcu_read_unlock(); return error; } @@ -390,7 +390,7 @@ int posix_cpu_timer_create(struct k_itimer *new_timer) INIT_LIST_HEAD(&new_timer->it.cpu.entry); - read_lock(&tasklist_lock); + rcu_read_lock(); if (CPUCLOCK_PERTHREAD(new_timer->it_clock)) { if (pid == 0) { p = current; @@ -404,7 +404,7 @@ int posix_cpu_timer_create(struct k_itimer *new_timer) p = current->group_leader; } else { p = find_task_by_vpid(pid); - if (p && !thread_group_leader(p)) + if (p && !has_group_leader_pid(p)) p = NULL; } } @@ -414,7 +414,7 @@ int posix_cpu_timer_create(struct k_itimer *new_timer) } else { ret = -EINVAL; } - read_unlock(&tasklist_lock); + rcu_read_unlock(); return ret; } -- cgit v1.2.2 From 2fd1f04089cb657c5d6c484b280ec4d3398aa157 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Tue, 1 Feb 2011 13:51:03 +0000 Subject: posix-timers: Cleanup struct initializers Cosmetic. No functional change Signed-off-by: Thomas Gleixner Acked-by: John Stultz Tested-by: Richard Cochran LKML-Reference: <20110201134417.745627057@linutronix.de> --- kernel/posix-cpu-timers.c | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-) (limited to 'kernel/posix-cpu-timers.c') diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c index 05bb7173850e..11b91dc0992b 100644 --- a/kernel/posix-cpu-timers.c +++ b/kernel/posix-cpu-timers.c @@ -1607,20 +1607,20 @@ static long thread_cpu_nsleep_restart(struct restart_block *restart_block) static __init int init_posix_cpu_timers(void) { struct k_clock process = { - .clock_getres = process_cpu_clock_getres, - .clock_get = process_cpu_clock_get, - .clock_set = do_posix_clock_nosettime, - .timer_create = process_cpu_timer_create, - .nsleep = process_cpu_nsleep, - .nsleep_restart = process_cpu_nsleep_restart, + .clock_getres = process_cpu_clock_getres, + .clock_get = process_cpu_clock_get, + .clock_set = do_posix_clock_nosettime, + .timer_create = process_cpu_timer_create, + .nsleep = process_cpu_nsleep, + .nsleep_restart = process_cpu_nsleep_restart, }; struct k_clock thread = { - .clock_getres = thread_cpu_clock_getres, - .clock_get = thread_cpu_clock_get, - .clock_set = do_posix_clock_nosettime, - .timer_create = thread_cpu_timer_create, - .nsleep = thread_cpu_nsleep, - .nsleep_restart = thread_cpu_nsleep_restart, + .clock_getres = thread_cpu_clock_getres, + .clock_get = thread_cpu_clock_get, + .clock_set = do_posix_clock_nosettime, + .timer_create = thread_cpu_timer_create, + .nsleep = thread_cpu_nsleep, + .nsleep_restart = thread_cpu_nsleep_restart, }; struct timespec ts; -- cgit v1.2.2 From 1976945eeaab5fa461735a6225a82c3cf1e65d62 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Tue, 1 Feb 2011 13:51:06 +0000 Subject: posix-timers: Introduce clock_posix_cpu The CLOCK_DISPATCH() macro is a horrible magic. We call common functions if a function pointer is not set. That's just backwards. To support dynamic file decriptor based clocks we need to cleanup that dispatch logic. Create a k_clock struct clock_posix_cpu which has all the posix-cpu-timer functions filled in. After the cleanup the functions can be made static. Signed-off-by: Thomas Gleixner Acked-by: John Stultz Tested-by: Richard Cochran LKML-Reference: <20110201134417.841974553@linutronix.de> --- kernel/posix-cpu-timers.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'kernel/posix-cpu-timers.c') diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c index 11b91dc0992b..816cd49a5ad9 100644 --- a/kernel/posix-cpu-timers.c +++ b/kernel/posix-cpu-timers.c @@ -1604,6 +1604,18 @@ static long thread_cpu_nsleep_restart(struct restart_block *restart_block) return -EINVAL; } +struct k_clock clock_posix_cpu = { + .clock_getres = posix_cpu_clock_getres, + .clock_set = posix_cpu_clock_set, + .clock_get = posix_cpu_clock_get, + .timer_create = posix_cpu_timer_create, + .nsleep = posix_cpu_nsleep, + .nsleep_restart = posix_cpu_nsleep_restart, + .timer_set = posix_cpu_timer_set, + .timer_del = posix_cpu_timer_del, + .timer_get = posix_cpu_timer_get, +}; + static __init int init_posix_cpu_timers(void) { struct k_clock process = { -- cgit v1.2.2 From 3751f9f29bcbc19bd10e92254a273486f150c245 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Tue, 1 Feb 2011 13:51:20 +0000 Subject: posix-timers: Cleanup restart_block usage posix timers still use the legacy arg0-arg3 members of restart_block. Use restart_block.nanosleep instead Signed-off-by: Thomas Gleixner Acked-by: John Stultz Tested-by: Richard Cochran LKML-Reference: <20110201134418.232288779@linutronix.de> --- kernel/posix-cpu-timers.c | 38 +++++++++++++++----------------------- 1 file changed, 15 insertions(+), 23 deletions(-) (limited to 'kernel/posix-cpu-timers.c') diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c index 816cd49a5ad9..9e617b00afa9 100644 --- a/kernel/posix-cpu-timers.c +++ b/kernel/posix-cpu-timers.c @@ -1485,7 +1485,7 @@ int posix_cpu_nsleep(const clockid_t which_clock, int flags, struct timespec *rqtp, struct timespec __user *rmtp) { struct restart_block *restart_block = - ¤t_thread_info()->restart_block; + ¤t_thread_info()->restart_block; struct itimerspec it; int error; @@ -1501,50 +1501,42 @@ int posix_cpu_nsleep(const clockid_t which_clock, int flags, if (error == -ERESTART_RESTARTBLOCK) { - if (flags & TIMER_ABSTIME) + if (flags & TIMER_ABSTIME) return -ERESTARTNOHAND; /* - * Report back to the user the time still remaining. - */ - if (rmtp != NULL && copy_to_user(rmtp, &it.it_value, sizeof *rmtp)) + * Report back to the user the time still remaining. + */ + if (rmtp && copy_to_user(rmtp, &it.it_value, sizeof *rmtp)) return -EFAULT; restart_block->fn = posix_cpu_nsleep_restart; - restart_block->arg0 = which_clock; - restart_block->arg1 = (unsigned long) rmtp; - restart_block->arg2 = rqtp->tv_sec; - restart_block->arg3 = rqtp->tv_nsec; + restart_block->nanosleep.index = which_clock; + restart_block->nanosleep.rmtp = rmtp; + restart_block->nanosleep.expires = timespec_to_ns(rqtp); } return error; } long posix_cpu_nsleep_restart(struct restart_block *restart_block) { - clockid_t which_clock = restart_block->arg0; - struct timespec __user *rmtp; + clockid_t which_clock = restart_block->nanosleep.index; struct timespec t; struct itimerspec it; int error; - rmtp = (struct timespec __user *) restart_block->arg1; - t.tv_sec = restart_block->arg2; - t.tv_nsec = restart_block->arg3; + t = ns_to_timespec(restart_block->nanosleep.expires); - restart_block->fn = do_no_restart_syscall; error = do_cpu_nanosleep(which_clock, TIMER_ABSTIME, &t, &it); if (error == -ERESTART_RESTARTBLOCK) { + struct timespec __user *rmtp = restart_block->nanosleep.rmtp; /* - * Report back to the user the time still remaining. - */ - if (rmtp != NULL && copy_to_user(rmtp, &it.it_value, sizeof *rmtp)) + * Report back to the user the time still remaining. + */ + if (rmtp && copy_to_user(rmtp, &it.it_value, sizeof *rmtp)) return -EFAULT; - restart_block->fn = posix_cpu_nsleep_restart; - restart_block->arg0 = which_clock; - restart_block->arg1 = (unsigned long) rmtp; - restart_block->arg2 = t.tv_sec; - restart_block->arg3 = t.tv_nsec; + restart_block->nanosleep.expires = timespec_to_ns(&t); } return error; -- cgit v1.2.2 From 79c9da0d0539fb341a1b48a2a5a23d974726de90 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Tue, 1 Feb 2011 13:51:45 +0000 Subject: posix-cpu-timers: Remove the stub nanosleep functions CLOCK_THREAD_CPUTIME_ID implements stub functions for nanosleep and nanosleep_restart, which return -EINVAL. That return value is wrong. The correct return value is -ENOTSUP. Remove the stubs and let the new dispatch code return the correct error code. Signed-off-by: Thomas Gleixner Acked-by: John Stultz Tested-by: Richard Cochran LKML-Reference: <20110201134418.422446502@linutronix.de> --- kernel/posix-cpu-timers.c | 11 ----------- 1 file changed, 11 deletions(-) (limited to 'kernel/posix-cpu-timers.c') diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c index 9e617b00afa9..8dc4cd7faf89 100644 --- a/kernel/posix-cpu-timers.c +++ b/kernel/posix-cpu-timers.c @@ -1586,15 +1586,6 @@ static int thread_cpu_timer_create(struct k_itimer *timer) timer->it_clock = THREAD_CLOCK; return posix_cpu_timer_create(timer); } -static int thread_cpu_nsleep(const clockid_t which_clock, int flags, - struct timespec *rqtp, struct timespec __user *rmtp) -{ - return -EINVAL; -} -static long thread_cpu_nsleep_restart(struct restart_block *restart_block) -{ - return -EINVAL; -} struct k_clock clock_posix_cpu = { .clock_getres = posix_cpu_clock_getres, @@ -1623,8 +1614,6 @@ static __init int init_posix_cpu_timers(void) .clock_get = thread_cpu_clock_get, .clock_set = do_posix_clock_nosettime, .timer_create = thread_cpu_timer_create, - .nsleep = thread_cpu_nsleep, - .nsleep_restart = thread_cpu_nsleep_restart, }; struct timespec ts; -- cgit v1.2.2 From 26f9a4796af330173d790c8d2b5e2efcc489e755 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Tue, 1 Feb 2011 13:51:48 +0000 Subject: posix-timers: Convert clock_settime to clockid_to_kclock() Use the new kclock decoding function in clock_settime and cleanup all kclocks which use the default functions. Rename the misnomed common_clock_set() to posix_clock_realtime_set(). Signed-off-by: Thomas Gleixner Acked-by: John Stultz Tested-by: Richard Cochran LKML-Reference: <20110201134418.518851246@linutronix.de> --- kernel/posix-cpu-timers.c | 2 -- 1 file changed, 2 deletions(-) (limited to 'kernel/posix-cpu-timers.c') diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c index 8dc4cd7faf89..504fbab10b82 100644 --- a/kernel/posix-cpu-timers.c +++ b/kernel/posix-cpu-timers.c @@ -1604,7 +1604,6 @@ static __init int init_posix_cpu_timers(void) struct k_clock process = { .clock_getres = process_cpu_clock_getres, .clock_get = process_cpu_clock_get, - .clock_set = do_posix_clock_nosettime, .timer_create = process_cpu_timer_create, .nsleep = process_cpu_nsleep, .nsleep_restart = process_cpu_nsleep_restart, @@ -1612,7 +1611,6 @@ static __init int init_posix_cpu_timers(void) struct k_clock thread = { .clock_getres = thread_cpu_clock_getres, .clock_get = thread_cpu_clock_get, - .clock_set = do_posix_clock_nosettime, .timer_create = thread_cpu_timer_create, }; struct timespec ts; -- cgit v1.2.2 From bc2c8ea483d73e95fc88f1fc9e7755180f89b892 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Tue, 1 Feb 2011 13:52:12 +0000 Subject: posix-timers: Make posix-cpu-timers functions static All functions are accessed via clock_posix_cpu now. So make them static. Signed-off-by: Thomas Gleixner Acked-by: John Stultz Tested-by: Richard Cochran LKML-Reference: <20110201134419.389755466@linutronix.de> --- kernel/posix-cpu-timers.c | 27 +++++++++++++++------------ 1 file changed, 15 insertions(+), 12 deletions(-) (limited to 'kernel/posix-cpu-timers.c') diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c index 504fbab10b82..609e187f43e7 100644 --- a/kernel/posix-cpu-timers.c +++ b/kernel/posix-cpu-timers.c @@ -176,7 +176,8 @@ static inline cputime_t virt_ticks(struct task_struct *p) return p->utime; } -int posix_cpu_clock_getres(const clockid_t which_clock, struct timespec *tp) +static int +posix_cpu_clock_getres(const clockid_t which_clock, struct timespec *tp) { int error = check_clock(which_clock); if (!error) { @@ -194,7 +195,8 @@ int posix_cpu_clock_getres(const clockid_t which_clock, struct timespec *tp) return error; } -int posix_cpu_clock_set(const clockid_t which_clock, const struct timespec *tp) +static int +posix_cpu_clock_set(const clockid_t which_clock, const struct timespec *tp) { /* * You can never reset a CPU clock, but we check for other errors @@ -317,7 +319,7 @@ static int cpu_clock_sample_group(const clockid_t which_clock, } -int posix_cpu_clock_get(const clockid_t which_clock, struct timespec *tp) +static int posix_cpu_clock_get(const clockid_t which_clock, struct timespec *tp) { const pid_t pid = CPUCLOCK_PID(which_clock); int error = -EINVAL; @@ -379,7 +381,7 @@ int posix_cpu_clock_get(const clockid_t which_clock, struct timespec *tp) * This is called from sys_timer_create() and do_cpu_nanosleep() with the * new timer already all-zeros initialized. */ -int posix_cpu_timer_create(struct k_itimer *new_timer) +static int posix_cpu_timer_create(struct k_itimer *new_timer) { int ret = 0; const pid_t pid = CPUCLOCK_PID(new_timer->it_clock); @@ -425,7 +427,7 @@ int posix_cpu_timer_create(struct k_itimer *new_timer) * If we return TIMER_RETRY, it's necessary to release the timer's lock * and try again. (This happens when the timer is in the middle of firing.) */ -int posix_cpu_timer_del(struct k_itimer *timer) +static int posix_cpu_timer_del(struct k_itimer *timer) { struct task_struct *p = timer->it.cpu.task; int ret = 0; @@ -665,8 +667,8 @@ static int cpu_timer_sample_group(const clockid_t which_clock, * If we return TIMER_RETRY, it's necessary to release the timer's lock * and try again. (This happens when the timer is in the middle of firing.) */ -int posix_cpu_timer_set(struct k_itimer *timer, int flags, - struct itimerspec *new, struct itimerspec *old) +static int posix_cpu_timer_set(struct k_itimer *timer, int flags, + struct itimerspec *new, struct itimerspec *old) { struct task_struct *p = timer->it.cpu.task; union cpu_time_count old_expires, new_expires, old_incr, val; @@ -820,7 +822,7 @@ int posix_cpu_timer_set(struct k_itimer *timer, int flags, return ret; } -void posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec *itp) +static void posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec *itp) { union cpu_time_count now; struct task_struct *p = timer->it.cpu.task; @@ -1481,8 +1483,10 @@ static int do_cpu_nanosleep(const clockid_t which_clock, int flags, return error; } -int posix_cpu_nsleep(const clockid_t which_clock, int flags, - struct timespec *rqtp, struct timespec __user *rmtp) +static long posix_cpu_nsleep_restart(struct restart_block *restart_block); + +static int posix_cpu_nsleep(const clockid_t which_clock, int flags, + struct timespec *rqtp, struct timespec __user *rmtp) { struct restart_block *restart_block = ¤t_thread_info()->restart_block; @@ -1517,7 +1521,7 @@ int posix_cpu_nsleep(const clockid_t which_clock, int flags, return error; } -long posix_cpu_nsleep_restart(struct restart_block *restart_block) +static long posix_cpu_nsleep_restart(struct restart_block *restart_block) { clockid_t which_clock = restart_block->nanosleep.index; struct timespec t; @@ -1542,7 +1546,6 @@ long posix_cpu_nsleep_restart(struct restart_block *restart_block) } - #define PROCESS_CLOCK MAKE_PROCESS_CPUCLOCK(0, CPUCLOCK_SCHED) #define THREAD_CLOCK MAKE_THREAD_CPUCLOCK(0, CPUCLOCK_SCHED) -- cgit v1.2.2 From 527087374faa488776a789375a7d6ea74fda6f71 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 2 Feb 2011 12:10:09 +0100 Subject: posix-timers: Cleanup namespace Rename register_posix_clock() to posix_timers_register_clock(). That's what the function really does. As a side effect this cleans up the posix_clock namespace for the upcoming dynamic posix_clock infrastructure. Signed-off-by: Thomas Gleixner Tested-by: Richard Cochran Cc: John Stultz LKML-Reference: --- kernel/posix-cpu-timers.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel/posix-cpu-timers.c') diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c index 609e187f43e7..67fea9d25d55 100644 --- a/kernel/posix-cpu-timers.c +++ b/kernel/posix-cpu-timers.c @@ -1618,8 +1618,8 @@ static __init int init_posix_cpu_timers(void) }; struct timespec ts; - register_posix_clock(CLOCK_PROCESS_CPUTIME_ID, &process); - register_posix_clock(CLOCK_THREAD_CPUTIME_ID, &thread); + posix_timers_register_clock(CLOCK_PROCESS_CPUTIME_ID, &process); + posix_timers_register_clock(CLOCK_THREAD_CPUTIME_ID, &thread); cputime_to_timespec(cputime_one_jiffy, &ts); onecputick = ts.tv_nsec; -- cgit v1.2.2 From 25985edcedea6396277003854657b5f3cb31a628 Mon Sep 17 00:00:00 2001 From: Lucas De Marchi Date: Wed, 30 Mar 2011 22:57:33 -0300 Subject: Fix common misspellings Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi --- kernel/posix-cpu-timers.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/posix-cpu-timers.c') diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c index 67fea9d25d55..0791b13df7bf 100644 --- a/kernel/posix-cpu-timers.c +++ b/kernel/posix-cpu-timers.c @@ -1347,7 +1347,7 @@ void run_posix_cpu_timers(struct task_struct *tsk) /* * Now that all the timers on our list have the firing flag, - * noone will touch their list entries but us. We'll take + * no one will touch their list entries but us. We'll take * each timer's lock before clearing its firing flag, so no * timer call will interfere. */ -- cgit v1.2.2 From ab8177bc53e8ae3a3ba6d200ce2c2dae263f7ee5 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Fri, 20 May 2011 13:05:15 +0200 Subject: hrtimers: Avoid touching inactive timer bases Instead of iterating over all possible timer bases avoid it by marking the active bases in the cpu base. Signed-off-by: Thomas Gleixner Reviewed-by: Peter Zijlstra --- kernel/posix-cpu-timers.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel/posix-cpu-timers.c') diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c index 0791b13df7bf..58f405b581e7 100644 --- a/kernel/posix-cpu-timers.c +++ b/kernel/posix-cpu-timers.c @@ -1514,7 +1514,7 @@ static int posix_cpu_nsleep(const clockid_t which_clock, int flags, return -EFAULT; restart_block->fn = posix_cpu_nsleep_restart; - restart_block->nanosleep.index = which_clock; + restart_block->nanosleep.clockid = which_clock; restart_block->nanosleep.rmtp = rmtp; restart_block->nanosleep.expires = timespec_to_ns(rqtp); } @@ -1523,7 +1523,7 @@ static int posix_cpu_nsleep(const clockid_t which_clock, int flags, static long posix_cpu_nsleep_restart(struct restart_block *restart_block) { - clockid_t which_clock = restart_block->nanosleep.index; + clockid_t which_clock = restart_block->nanosleep.clockid; struct timespec t; struct itimerspec it; int error; -- cgit v1.2.2