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-rw-r--r--kernel/cgroup.c48
-rw-r--r--kernel/compat.c24
-rw-r--r--kernel/cpuset.c9
-rw-r--r--kernel/events/core.c10
-rw-r--r--kernel/futex.c1
-rw-r--r--kernel/irq/chip.c1
-rw-r--r--kernel/kcmp.c7
-rw-r--r--kernel/kexec.c11
-rw-r--r--kernel/power/power.h1
-rw-r--r--kernel/power/snapshot.c50
-rw-r--r--kernel/power/suspend.c2
-rw-r--r--kernel/power/suspend_test.c31
-rw-r--r--kernel/printk/printk.c6
-rw-r--r--kernel/rcu/tree.h2
-rw-r--r--kernel/rcu/tree_plugin.h22
-rw-r--r--kernel/resource.c11
-rw-r--r--kernel/time/alarmtimer.c34
-rw-r--r--kernel/time/tick-sched.c14
-rw-r--r--kernel/time/time.c56
-rw-r--r--kernel/time/timekeeping.c5
-rw-r--r--kernel/trace/ring_buffer.c16
21 files changed, 227 insertions, 134 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 7dc8788cfd52..3a73f995a81e 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);
}
@@ -3970,7 +3985,6 @@ static int pidlist_array_load(struct cgroup *cgrp, enum cgroup_filetype type,
l = cgroup_pidlist_find_create(cgrp, type);
if (!l) {
- mutex_unlock(&cgrp->pidlist_mutex);
pidlist_free(array);
return -ENOMEM;
}
@@ -4387,6 +4401,15 @@ 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 +4566,11 @@ 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 +4848,6 @@ 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 +5434,7 @@ 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/compat.c b/kernel/compat.c
index 633394f442f8..ebb3c369d03d 100644
--- a/kernel/compat.c
+++ b/kernel/compat.c
@@ -226,7 +226,7 @@ static long compat_nanosleep_restart(struct restart_block *restart)
ret = hrtimer_nanosleep_restart(restart);
set_fs(oldfs);
- if (ret) {
+ if (ret == -ERESTART_RESTARTBLOCK) {
rmtp = restart->nanosleep.compat_rmtp;
if (rmtp && compat_put_timespec(&rmt, rmtp))
@@ -256,7 +256,26 @@ COMPAT_SYSCALL_DEFINE2(nanosleep, struct compat_timespec __user *, rqtp,
HRTIMER_MODE_REL, CLOCK_MONOTONIC);
set_fs(oldfs);
- if (ret) {
+ /*
+ * hrtimer_nanosleep() can only return 0 or
+ * -ERESTART_RESTARTBLOCK here because:
+ *
+ * - we call it with HRTIMER_MODE_REL and therefor exclude the
+ * -ERESTARTNOHAND return path.
+ *
+ * - we supply the rmtp argument from the task stack (due to
+ * the necessary compat conversion. So the update cannot
+ * fail, which excludes the -EFAULT return path as well. If
+ * it fails nevertheless we have a bigger problem and wont
+ * reach this place anymore.
+ *
+ * - if the return value is 0, we do not have to update rmtp
+ * because there is no remaining time.
+ *
+ * We check for -ERESTART_RESTARTBLOCK nevertheless if the
+ * core implementation decides to return random nonsense.
+ */
+ if (ret == -ERESTART_RESTARTBLOCK) {
struct restart_block *restart
= &current_thread_info()->restart_block;
@@ -266,7 +285,6 @@ COMPAT_SYSCALL_DEFINE2(nanosleep, struct compat_timespec __user *, rqtp,
if (rmtp && compat_put_timespec(&rmt, rmtp))
return -EFAULT;
}
-
return ret;
}
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 22874d7cf2c0..52cb04c993b7 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -365,13 +365,14 @@ static void cpuset_update_task_spread_flag(struct cpuset *cs,
struct task_struct *tsk)
{
if (is_spread_page(cs))
- tsk->flags |= PF_SPREAD_PAGE;
+ task_set_spread_page(tsk);
else
- tsk->flags &= ~PF_SPREAD_PAGE;
+ task_clear_spread_page(tsk);
+
if (is_spread_slab(cs))
- tsk->flags |= PF_SPREAD_SLAB;
+ task_set_spread_slab(tsk);
else
- tsk->flags &= ~PF_SPREAD_SLAB;
+ task_clear_spread_slab(tsk);
}
/*
diff --git a/kernel/events/core.c b/kernel/events/core.c
index f9c1ed002dbc..d640a8b4dcbc 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -1524,6 +1524,11 @@ retry:
*/
if (ctx->is_active) {
raw_spin_unlock_irq(&ctx->lock);
+ /*
+ * Reload the task pointer, it might have been changed by
+ * a concurrent perf_event_context_sched_out().
+ */
+ task = ctx->task;
goto retry;
}
@@ -1967,6 +1972,11 @@ retry:
*/
if (ctx->is_active) {
raw_spin_unlock_irq(&ctx->lock);
+ /*
+ * Reload the task pointer, it might have been changed by
+ * a concurrent perf_event_context_sched_out().
+ */
+ task = ctx->task;
goto retry;
}
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/irq/chip.c b/kernel/irq/chip.c
index a2b28a2fd7b1..6223fab9a9d2 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -517,6 +517,7 @@ out:
chip->irq_eoi(&desc->irq_data);
raw_spin_unlock(&desc->lock);
}
+EXPORT_SYMBOL_GPL(handle_fasteoi_irq);
/**
* handle_edge_irq - edge type IRQ handler
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/kexec.c b/kernel/kexec.c
index 0b49a0a58102..2bee072268d9 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -64,7 +64,9 @@ bool kexec_in_progress = false;
char __weak kexec_purgatory[0];
size_t __weak kexec_purgatory_size = 0;
+#ifdef CONFIG_KEXEC_FILE
static int kexec_calculate_store_digests(struct kimage *image);
+#endif
/* Location of the reserved area for the crash kernel */
struct resource crashk_res = {
@@ -341,6 +343,7 @@ out_free_image:
return ret;
}
+#ifdef CONFIG_KEXEC_FILE
static int copy_file_from_fd(int fd, void **buf, unsigned long *buf_len)
{
struct fd f = fdget(fd);
@@ -612,6 +615,9 @@ out_free_image:
kfree(image);
return ret;
}
+#else /* CONFIG_KEXEC_FILE */
+static inline void kimage_file_post_load_cleanup(struct kimage *image) { }
+#endif /* CONFIG_KEXEC_FILE */
static int kimage_is_destination_range(struct kimage *image,
unsigned long start,
@@ -1375,6 +1381,7 @@ COMPAT_SYSCALL_DEFINE4(kexec_load, compat_ulong_t, entry,
}
#endif
+#ifdef CONFIG_KEXEC_FILE
SYSCALL_DEFINE5(kexec_file_load, int, kernel_fd, int, initrd_fd,
unsigned long, cmdline_len, const char __user *, cmdline_ptr,
unsigned long, flags)
@@ -1451,6 +1458,8 @@ out:
return ret;
}
+#endif /* CONFIG_KEXEC_FILE */
+
void crash_kexec(struct pt_regs *regs)
{
/* Take the kexec_mutex here to prevent sys_kexec_load
@@ -2006,6 +2015,7 @@ static int __init crash_save_vmcoreinfo_init(void)
subsys_initcall(crash_save_vmcoreinfo_init);
+#ifdef CONFIG_KEXEC_FILE
static int __kexec_add_segment(struct kimage *image, char *buf,
unsigned long bufsz, unsigned long mem,
unsigned long memsz)
@@ -2682,6 +2692,7 @@ int kexec_purgatory_get_set_symbol(struct kimage *image, const char *name,
return 0;
}
+#endif /* CONFIG_KEXEC_FILE */
/*
* Move into place and start executing a preloaded standalone
diff --git a/kernel/power/power.h b/kernel/power/power.h
index 5d49dcac2537..2df883a9d3cb 100644
--- a/kernel/power/power.h
+++ b/kernel/power/power.h
@@ -179,6 +179,7 @@ extern void swsusp_show_speed(struct timeval *, struct timeval *,
#ifdef CONFIG_SUSPEND
/* kernel/power/suspend.c */
+extern const char *pm_labels[];
extern const char *pm_states[];
extern int suspend_devices_and_enter(suspend_state_t state);
diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
index c4b8093c80b3..f1604d8cf489 100644
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -725,14 +725,6 @@ static void memory_bm_clear_bit(struct memory_bitmap *bm, unsigned long pfn)
clear_bit(bit, addr);
}
-static void memory_bm_clear_current(struct memory_bitmap *bm)
-{
- int bit;
-
- bit = max(bm->cur.node_bit - 1, 0);
- clear_bit(bit, bm->cur.node->data);
-}
-
static int memory_bm_test_bit(struct memory_bitmap *bm, unsigned long pfn)
{
void *addr;
@@ -1341,35 +1333,23 @@ static struct memory_bitmap copy_bm;
void swsusp_free(void)
{
- unsigned long fb_pfn, fr_pfn;
-
- memory_bm_position_reset(forbidden_pages_map);
- memory_bm_position_reset(free_pages_map);
-
-loop:
- fr_pfn = memory_bm_next_pfn(free_pages_map);
- fb_pfn = memory_bm_next_pfn(forbidden_pages_map);
-
- /*
- * Find the next bit set in both bitmaps. This is guaranteed to
- * terminate when fb_pfn == fr_pfn == BM_END_OF_MAP.
- */
- do {
- if (fb_pfn < fr_pfn)
- fb_pfn = memory_bm_next_pfn(forbidden_pages_map);
- if (fr_pfn < fb_pfn)
- fr_pfn = memory_bm_next_pfn(free_pages_map);
- } while (fb_pfn != fr_pfn);
-
- if (fr_pfn != BM_END_OF_MAP && pfn_valid(fr_pfn)) {
- struct page *page = pfn_to_page(fr_pfn);
+ struct zone *zone;
+ unsigned long pfn, max_zone_pfn;
- memory_bm_clear_current(forbidden_pages_map);
- memory_bm_clear_current(free_pages_map);
- __free_page(page);
- goto loop;
+ for_each_populated_zone(zone) {
+ max_zone_pfn = zone_end_pfn(zone);
+ for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
+ if (pfn_valid(pfn)) {
+ struct page *page = pfn_to_page(pfn);
+
+ if (swsusp_page_is_forbidden(page) &&
+ swsusp_page_is_free(page)) {
+ swsusp_unset_page_forbidden(page);
+ swsusp_unset_page_free(page);
+ __free_page(page);
+ }
+ }
}
-
nr_copy_pages = 0;
nr_meta_pages = 0;
restore_pblist = NULL;
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index 6dadb25cb0d8..18c62195660f 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -31,7 +31,7 @@
#include "power.h"
-static const char *pm_labels[] = { "mem", "standby", "freeze", };
+const char *pm_labels[] = { "mem", "standby", "freeze", NULL };
const char *pm_states[PM_SUSPEND_MAX];
static const struct platform_suspend_ops *suspend_ops;
diff --git a/kernel/power/suspend_test.c b/kernel/power/suspend_test.c
index 2f524928b6aa..bd91bc177c93 100644
--- a/kernel/power/suspend_test.c
+++ b/kernel/power/suspend_test.c
@@ -129,20 +129,20 @@ static int __init has_wakealarm(struct device *dev, const void *data)
* at startup time. They're normally disabled, for faster boot and because
* we can't know which states really work on this particular system.
*/
-static suspend_state_t test_state __initdata = PM_SUSPEND_ON;
+static const char *test_state_label __initdata;
static char warn_bad_state[] __initdata =
KERN_WARNING "PM: can't test '%s' suspend state\n";
static int __init setup_test_suspend(char *value)
{
- suspend_state_t i;
+ int i;
/* "=mem" ==> "mem" */
value++;
- for (i = PM_SUSPEND_MIN; i < PM_SUSPEND_MAX; i++)
- if (!strcmp(pm_states[i], value)) {
- test_state = i;
+ for (i = 0; pm_labels[i]; i++)
+ if (!strcmp(pm_labels[i], value)) {
+ test_state_label = pm_labels[i];
return 0;
}
@@ -158,13 +158,21 @@ static int __init test_suspend(void)
struct rtc_device *rtc = NULL;
struct device *dev;
+ suspend_state_t test_state;
/* PM is initialized by now; is that state testable? */
- if (test_state == PM_SUSPEND_ON)
- goto done;
- if (!pm_states[test_state]) {
- printk(warn_bad_state, pm_states[test_state]);
- goto done;
+ if (!test_state_label)
+ return 0;
+
+ for (test_state = PM_SUSPEND_MIN; test_state < PM_SUSPEND_MAX; test_state++) {
+ const char *state_label = pm_states[test_state];
+
+ if (state_label && !strcmp(test_state_label, state_label))
+ break;
+ }
+ if (test_state == PM_SUSPEND_MAX) {
+ printk(warn_bad_state, test_state_label);
+ return 0;
}
/* RTCs have initialized by now too ... can we use one? */
@@ -173,13 +181,12 @@ static int __init test_suspend(void)
rtc = rtc_class_open(dev_name(dev));
if (!rtc) {
printk(warn_no_rtc);
- goto done;
+ return 0;
}
/* go for it */
test_wakealarm(rtc, test_state);
rtc_class_close(rtc);
-done:
return 0;
}
late_initcall(test_suspend);
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/rcu/tree.h b/kernel/rcu/tree.h
index 71e64c718f75..6a86eb7bac45 100644
--- a/kernel/rcu/tree.h
+++ b/kernel/rcu/tree.h
@@ -358,7 +358,7 @@ struct rcu_data {
struct rcu_head **nocb_gp_tail;
long nocb_gp_count;
long nocb_gp_count_lazy;
- bool nocb_leader_wake; /* Is the nocb leader thread awake? */
+ bool nocb_leader_sleep; /* Is the nocb leader thread asleep? */
struct rcu_data *nocb_next_follower;
/* Next follower in wakeup chain. */
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 00dc411e9676..a7997e272564 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -2074,9 +2074,9 @@ static void wake_nocb_leader(struct rcu_data *rdp, bool force)
if (!ACCESS_ONCE(rdp_leader->nocb_kthread))
return;
- if (!ACCESS_ONCE(rdp_leader->nocb_leader_wake) || force) {
+ if (ACCESS_ONCE(rdp_leader->nocb_leader_sleep) || force) {
/* Prior xchg orders against prior callback enqueue. */
- ACCESS_ONCE(rdp_leader->nocb_leader_wake) = true;
+ ACCESS_ONCE(rdp_leader->nocb_leader_sleep) = false;
wake_up(&rdp_leader->nocb_wq);
}
}
@@ -2253,7 +2253,7 @@ wait_again:
if (!rcu_nocb_poll) {
trace_rcu_nocb_wake(my_rdp->rsp->name, my_rdp->cpu, "Sleep");
wait_event_interruptible(my_rdp->nocb_wq,
- ACCESS_ONCE(my_rdp->nocb_leader_wake));
+ !ACCESS_ONCE(my_rdp->nocb_leader_sleep));
/* Memory barrier handled by smp_mb() calls below and repoll. */
} else if (firsttime) {
firsttime = false; /* Don't drown trace log with "Poll"! */
@@ -2292,12 +2292,12 @@ wait_again:
schedule_timeout_interruptible(1);
/* Rescan in case we were a victim of memory ordering. */
- my_rdp->nocb_leader_wake = false;
- smp_mb(); /* Ensure _wake false before scan. */
+ my_rdp->nocb_leader_sleep = true;
+ smp_mb(); /* Ensure _sleep true before scan. */
for (rdp = my_rdp; rdp; rdp = rdp->nocb_next_follower)
if (ACCESS_ONCE(rdp->nocb_head)) {
/* Found CB, so short-circuit next wait. */
- my_rdp->nocb_leader_wake = true;
+ my_rdp->nocb_leader_sleep = false;
break;
}
goto wait_again;
@@ -2307,17 +2307,17 @@ wait_again:
rcu_nocb_wait_gp(my_rdp);
/*
- * We left ->nocb_leader_wake set to reduce cache thrashing.
- * We clear it now, but recheck for new callbacks while
+ * We left ->nocb_leader_sleep unset to reduce cache thrashing.
+ * We set it now, but recheck for new callbacks while
* traversing our follower list.
*/
- my_rdp->nocb_leader_wake = false;
- smp_mb(); /* Ensure _wake false before scan of ->nocb_head. */
+ my_rdp->nocb_leader_sleep = true;
+ smp_mb(); /* Ensure _sleep true before scan of ->nocb_head. */
/* Each pass through the following loop wakes a follower, if needed. */
for (rdp = my_rdp; rdp; rdp = rdp->nocb_next_follower) {
if (ACCESS_ONCE(rdp->nocb_head))
- my_rdp->nocb_leader_wake = true; /* No need to wait. */
+ my_rdp->nocb_leader_sleep = false;/* No need to sleep.*/
if (!rdp->nocb_gp_head)
continue; /* No CBs, so no need to wake follower. */
diff --git a/kernel/resource.c b/kernel/resource.c
index da14b8d09296..60c5a3856ab7 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -351,15 +351,12 @@ static int find_next_iomem_res(struct resource *res, char *name,
end = res->end;
BUG_ON(start >= end);
- read_lock(&resource_lock);
-
- if (first_level_children_only) {
- p = iomem_resource.child;
+ if (first_level_children_only)
sibling_only = true;
- } else
- p = &iomem_resource;
- while ((p = next_resource(p, sibling_only))) {
+ read_lock(&resource_lock);
+
+ for (p = iomem_resource.child; p; p = next_resource(p, sibling_only)) {
if (p->flags != res->flags)
continue;
if (name && strcmp(p->name, name))
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/tick-sched.c b/kernel/time/tick-sched.c
index 99aa6ee3908f..f654a8a298fa 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -225,6 +225,20 @@ static DEFINE_PER_CPU(struct irq_work, nohz_full_kick_work) = {
};
/*
+ * Kick this CPU if it's full dynticks in order to force it to
+ * re-evaluate its dependency on the tick and restart it if necessary.
+ * This kick, unlike tick_nohz_full_kick_cpu() and tick_nohz_full_kick_all(),
+ * is NMI safe.
+ */
+void tick_nohz_full_kick(void)
+{
+ if (!tick_nohz_full_cpu(smp_processor_id()))
+ return;
+
+ irq_work_queue(&__get_cpu_var(nohz_full_kick_work));
+}
+
+/*
* Kick the CPU if it's full dynticks in order to force it to
* re-evaluate its dependency on the tick and restart it if necessary.
*/
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);
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index fb4a9c2cf8d9..ec1791fae965 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -442,11 +442,12 @@ static void timekeeping_update(struct timekeeper *tk, unsigned int action)
tk->ntp_error = 0;
ntp_clear();
}
- update_vsyscall(tk);
- update_pvclock_gtod(tk, action & TK_CLOCK_WAS_SET);
tk_update_ktime_data(tk);
+ update_vsyscall(tk);
+ update_pvclock_gtod(tk, action & TK_CLOCK_WAS_SET);
+
if (action & TK_MIRROR)
memcpy(&shadow_timekeeper, &tk_core.timekeeper,
sizeof(tk_core.timekeeper));
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index afb04b9b818a..b38fb2b9e237 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -626,8 +626,22 @@ int ring_buffer_poll_wait(struct ring_buffer *buffer, int cpu,
work = &cpu_buffer->irq_work;
}
- work->waiters_pending = true;
poll_wait(filp, &work->waiters, poll_table);
+ work->waiters_pending = true;
+ /*
+ * There's a tight race between setting the waiters_pending and
+ * checking if the ring buffer is empty. Once the waiters_pending bit
+ * is set, the next event will wake the task up, but we can get stuck
+ * if there's only a single event in.
+ *
+ * FIXME: Ideally, we need a memory barrier on the writer side as well,
+ * but adding a memory barrier to all events will cause too much of a
+ * performance hit in the fast path. We only need a memory barrier when
+ * the buffer goes from empty to having content. But as this race is
+ * extremely small, and it's not a problem if another event comes in, we
+ * will fix it later.
+ */
+ smp_mb();
if ((cpu == RING_BUFFER_ALL_CPUS && !ring_buffer_empty(buffer)) ||
(cpu != RING_BUFFER_ALL_CPUS && !ring_buffer_empty_cpu(buffer, cpu)))
generated by cgit v1.2.3 (git 2.39.0) at 2024-07-15 05:31:09 +0300