diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/cgroup.c | 47 | ||||
| -rw-r--r-- | kernel/futex.c | 1 | ||||
| -rw-r--r-- | kernel/kcmp.c | 7 | ||||
| -rw-r--r-- | kernel/printk/printk.c | 6 | ||||
| -rw-r--r-- | kernel/time/alarmtimer.c | 34 | ||||
| -rw-r--r-- | kernel/time/time.c | 56 |
6 files changed, 95 insertions, 56 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 7dc8788cfd52..940aced4ed00 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -1035,6 +1035,11 @@ static void cgroup_get(struct cgroup *cgrp) css_get(&cgrp->self); } +static bool cgroup_tryget(struct cgroup *cgrp) +{ + return css_tryget(&cgrp->self); +} + static void cgroup_put(struct cgroup *cgrp) { css_put(&cgrp->self); @@ -1147,7 +1152,8 @@ static struct cgroup *cgroup_kn_lock_live(struct kernfs_node *kn) * protection against removal. Ensure @cgrp stays accessible and * break the active_ref protection. */ - cgroup_get(cgrp); + if (!cgroup_tryget(cgrp)) + return NULL; kernfs_break_active_protection(kn); mutex_lock(&cgroup_mutex); @@ -3271,8 +3277,17 @@ int cgroup_add_legacy_cftypes(struct cgroup_subsys *ss, struct cftype *cfts) { struct cftype *cft; - for (cft = cfts; cft && cft->name[0] != '\0'; cft++) - cft->flags |= __CFTYPE_NOT_ON_DFL; + /* + * If legacy_flies_on_dfl, we want to show the legacy files on the + * dfl hierarchy but iff the target subsystem hasn't been updated + * for the dfl hierarchy yet. + */ + if (!cgroup_legacy_files_on_dfl || + ss->dfl_cftypes != ss->legacy_cftypes) { + for (cft = cfts; cft && cft->name[0] != '\0'; cft++) + cft->flags |= __CFTYPE_NOT_ON_DFL; + } + return cgroup_add_cftypes(ss, cfts); } @@ -4387,6 +4402,15 @@ static void css_release_work_fn(struct work_struct *work) /* cgroup release path */ cgroup_idr_remove(&cgrp->root->cgroup_idr, cgrp->id); cgrp->id = -1; + + /* + * There are two control paths which try to determine + * cgroup from dentry without going through kernfs - + * cgroupstats_build() and css_tryget_online_from_dir(). + * Those are supported by RCU protecting clearing of + * cgrp->kn->priv backpointer. + */ + RCU_INIT_POINTER(*(void __rcu __force **)&cgrp->kn->priv, NULL); } mutex_unlock(&cgroup_mutex); @@ -4543,6 +4567,11 @@ static int cgroup_mkdir(struct kernfs_node *parent_kn, const char *name, struct cftype *base_files; int ssid, ret; + /* Do not accept '\n' to prevent making /proc/<pid>/cgroup unparsable. + */ + if (strchr(name, '\n')) + return -EINVAL; + parent = cgroup_kn_lock_live(parent_kn); if (!parent) return -ENODEV; @@ -4820,16 +4849,6 @@ static int cgroup_rmdir(struct kernfs_node *kn) cgroup_kn_unlock(kn); - /* - * There are two control paths which try to determine cgroup from - * dentry without going through kernfs - cgroupstats_build() and - * css_tryget_online_from_dir(). Those are supported by RCU - * protecting clearing of cgrp->kn->priv backpointer, which should - * happen after all files under it have been removed. - */ - if (!ret) - RCU_INIT_POINTER(*(void __rcu __force **)&kn->priv, NULL); - cgroup_put(cgrp); return ret; } @@ -5416,7 +5435,7 @@ struct cgroup_subsys_state *css_tryget_online_from_dir(struct dentry *dentry, /* * This path doesn't originate from kernfs and @kn could already * have been or be removed at any point. @kn->priv is RCU - * protected for this access. See cgroup_rmdir() for details. + * protected for this access. See css_release_work_fn() for details. */ cgrp = rcu_dereference(kn->priv); if (cgrp) diff --git a/kernel/futex.c b/kernel/futex.c index d3a9d946d0b7..815d7af2ffe8 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -2592,6 +2592,7 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags, * shared futexes. We need to compare the keys: */ if (match_futex(&q.key, &key2)) { + queue_unlock(hb); ret = -EINVAL; goto out_put_keys; } diff --git a/kernel/kcmp.c b/kernel/kcmp.c index e30ac0fe61c3..0aa69ea1d8fd 100644 --- a/kernel/kcmp.c +++ b/kernel/kcmp.c @@ -44,11 +44,12 @@ static long kptr_obfuscate(long v, int type) */ static int kcmp_ptr(void *v1, void *v2, enum kcmp_type type) { - long ret; + long t1, t2; - ret = kptr_obfuscate((long)v1, type) - kptr_obfuscate((long)v2, type); + t1 = kptr_obfuscate((long)v1, type); + t2 = kptr_obfuscate((long)v2, type); - return (ret < 0) | ((ret > 0) << 1); + return (t1 < t2) | ((t1 > t2) << 1); } /* The caller must have pinned the task */ diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index e04c455a0e38..1ce770687ea8 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -1665,15 +1665,15 @@ asmlinkage int vprintk_emit(int facility, int level, raw_spin_lock(&logbuf_lock); logbuf_cpu = this_cpu; - if (recursion_bug) { + if (unlikely(recursion_bug)) { static const char recursion_msg[] = "BUG: recent printk recursion!"; recursion_bug = 0; - text_len = strlen(recursion_msg); /* emit KERN_CRIT message */ printed_len += log_store(0, 2, LOG_PREFIX|LOG_NEWLINE, 0, - NULL, 0, recursion_msg, text_len); + NULL, 0, recursion_msg, + strlen(recursion_msg)); } /* diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c index 4aec4a457431..a7077d3ae52f 100644 --- a/kernel/time/alarmtimer.c +++ b/kernel/time/alarmtimer.c @@ -464,18 +464,26 @@ static enum alarmtimer_type clock2alarm(clockid_t clockid) static enum alarmtimer_restart alarm_handle_timer(struct alarm *alarm, ktime_t now) { + unsigned long flags; struct k_itimer *ptr = container_of(alarm, struct k_itimer, it.alarm.alarmtimer); - if (posix_timer_event(ptr, 0) != 0) - ptr->it_overrun++; + enum alarmtimer_restart result = ALARMTIMER_NORESTART; + + spin_lock_irqsave(&ptr->it_lock, flags); + if ((ptr->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE) { + if (posix_timer_event(ptr, 0) != 0) + ptr->it_overrun++; + } /* Re-add periodic timers */ if (ptr->it.alarm.interval.tv64) { ptr->it_overrun += alarm_forward(alarm, now, ptr->it.alarm.interval); - return ALARMTIMER_RESTART; + result = ALARMTIMER_RESTART; } - return ALARMTIMER_NORESTART; + spin_unlock_irqrestore(&ptr->it_lock, flags); + + return result; } /** @@ -541,18 +549,22 @@ static int alarm_timer_create(struct k_itimer *new_timer) * @new_timer: k_itimer pointer * @cur_setting: itimerspec data to fill * - * Copies the itimerspec data out from the k_itimer + * Copies out the current itimerspec data */ static void alarm_timer_get(struct k_itimer *timr, struct itimerspec *cur_setting) { - memset(cur_setting, 0, sizeof(struct itimerspec)); + ktime_t relative_expiry_time = + alarm_expires_remaining(&(timr->it.alarm.alarmtimer)); + + if (ktime_to_ns(relative_expiry_time) > 0) { + cur_setting->it_value = ktime_to_timespec(relative_expiry_time); + } else { + cur_setting->it_value.tv_sec = 0; + cur_setting->it_value.tv_nsec = 0; + } - cur_setting->it_interval = - ktime_to_timespec(timr->it.alarm.interval); - cur_setting->it_value = - ktime_to_timespec(timr->it.alarm.alarmtimer.node.expires); - return; + cur_setting->it_interval = ktime_to_timespec(timr->it.alarm.interval); } /** diff --git a/kernel/time/time.c b/kernel/time/time.c index f0294ba14634..a9ae20fb0b11 100644 --- a/kernel/time/time.c +++ b/kernel/time/time.c @@ -559,17 +559,20 @@ EXPORT_SYMBOL(usecs_to_jiffies); * that a remainder subtract here would not do the right thing as the * resolution values don't fall on second boundries. I.e. the line: * nsec -= nsec % TICK_NSEC; is NOT a correct resolution rounding. + * Note that due to the small error in the multiplier here, this + * rounding is incorrect for sufficiently large values of tv_nsec, but + * well formed timespecs should have tv_nsec < NSEC_PER_SEC, so we're + * OK. * * Rather, we just shift the bits off the right. * * The >> (NSEC_JIFFIE_SC - SEC_JIFFIE_SC) converts the scaled nsec * value to a scaled second value. */ -unsigned long -timespec_to_jiffies(const struct timespec *value) +static unsigned long +__timespec_to_jiffies(unsigned long sec, long nsec) { - unsigned long sec = value->tv_sec; - long nsec = value->tv_nsec + TICK_NSEC - 1; + nsec = nsec + TICK_NSEC - 1; if (sec >= MAX_SEC_IN_JIFFIES){ sec = MAX_SEC_IN_JIFFIES; @@ -580,6 +583,13 @@ timespec_to_jiffies(const struct timespec *value) (NSEC_JIFFIE_SC - SEC_JIFFIE_SC))) >> SEC_JIFFIE_SC; } + +unsigned long +timespec_to_jiffies(const struct timespec *value) +{ + return __timespec_to_jiffies(value->tv_sec, value->tv_nsec); +} + EXPORT_SYMBOL(timespec_to_jiffies); void @@ -596,31 +606,27 @@ jiffies_to_timespec(const unsigned long jiffies, struct timespec *value) } EXPORT_SYMBOL(jiffies_to_timespec); -/* Same for "timeval" - * - * Well, almost. The problem here is that the real system resolution is - * in nanoseconds and the value being converted is in micro seconds. - * Also for some machines (those that use HZ = 1024, in-particular), - * there is a LARGE error in the tick size in microseconds. - - * The solution we use is to do the rounding AFTER we convert the - * microsecond part. Thus the USEC_ROUND, the bits to be shifted off. - * Instruction wise, this should cost only an additional add with carry - * instruction above the way it was done above. +/* + * We could use a similar algorithm to timespec_to_jiffies (with a + * different multiplier for usec instead of nsec). But this has a + * problem with rounding: we can't exactly add TICK_NSEC - 1 to the + * usec value, since it's not necessarily integral. + * + * We could instead round in the intermediate scaled representation + * (i.e. in units of 1/2^(large scale) jiffies) but that's also + * perilous: the scaling introduces a small positive error, which + * combined with a division-rounding-upward (i.e. adding 2^(scale) - 1 + * units to the intermediate before shifting) leads to accidental + * overflow and overestimates. + * + * At the cost of one additional multiplication by a constant, just + * use the timespec implementation. */ unsigned long timeval_to_jiffies(const struct timeval *value) { - unsigned long sec = value->tv_sec; - long usec = value->tv_usec; - - if (sec >= MAX_SEC_IN_JIFFIES){ - sec = MAX_SEC_IN_JIFFIES; - usec = 0; - } - return (((u64)sec * SEC_CONVERSION) + - (((u64)usec * USEC_CONVERSION + USEC_ROUND) >> - (USEC_JIFFIE_SC - SEC_JIFFIE_SC))) >> SEC_JIFFIE_SC; + return __timespec_to_jiffies(value->tv_sec, + value->tv_usec * NSEC_PER_USEC); } EXPORT_SYMBOL(timeval_to_jiffies); |