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Diffstat (limited to 'fs/timerfd.c')
-rw-r--r--fs/timerfd.c51
1 files changed, 31 insertions, 20 deletions
diff --git a/fs/timerfd.c b/fs/timerfd.c
index 9ae4abb4110b..c543cdb5f8ed 100644
--- a/fs/timerfd.c
+++ b/fs/timerfd.c
@@ -40,6 +40,7 @@ struct timerfd_ctx {
short unsigned settime_flags; /* to show in fdinfo */
struct rcu_head rcu;
struct list_head clist;
+ spinlock_t cancel_lock;
bool might_cancel;
};
@@ -55,7 +56,7 @@ static inline bool isalarm(struct timerfd_ctx *ctx)
/*
* This gets called when the timer event triggers. We set the "expired"
* flag, but we do not re-arm the timer (in case it's necessary,
- * tintv.tv64 != 0) until the timer is accessed.
+ * tintv != 0) until the timer is accessed.
*/
static void timerfd_triggered(struct timerfd_ctx *ctx)
{
@@ -93,7 +94,7 @@ static enum alarmtimer_restart timerfd_alarmproc(struct alarm *alarm,
*/
void timerfd_clock_was_set(void)
{
- ktime_t moffs = ktime_mono_to_real((ktime_t){ .tv64 = 0 });
+ ktime_t moffs = ktime_mono_to_real(0);
struct timerfd_ctx *ctx;
unsigned long flags;
@@ -102,8 +103,8 @@ void timerfd_clock_was_set(void)
if (!ctx->might_cancel)
continue;
spin_lock_irqsave(&ctx->wqh.lock, flags);
- if (ctx->moffs.tv64 != moffs.tv64) {
- ctx->moffs.tv64 = KTIME_MAX;
+ if (ctx->moffs != moffs) {
+ ctx->moffs = KTIME_MAX;
ctx->ticks++;
wake_up_locked(&ctx->wqh);
}
@@ -112,7 +113,7 @@ void timerfd_clock_was_set(void)
rcu_read_unlock();
}
-static void timerfd_remove_cancel(struct timerfd_ctx *ctx)
+static void __timerfd_remove_cancel(struct timerfd_ctx *ctx)
{
if (ctx->might_cancel) {
ctx->might_cancel = false;
@@ -122,16 +123,24 @@ static void timerfd_remove_cancel(struct timerfd_ctx *ctx)
}
}
+static void timerfd_remove_cancel(struct timerfd_ctx *ctx)
+{
+ spin_lock(&ctx->cancel_lock);
+ __timerfd_remove_cancel(ctx);
+ spin_unlock(&ctx->cancel_lock);
+}
+
static bool timerfd_canceled(struct timerfd_ctx *ctx)
{
- if (!ctx->might_cancel || ctx->moffs.tv64 != KTIME_MAX)
+ if (!ctx->might_cancel || ctx->moffs != KTIME_MAX)
return false;
- ctx->moffs = ktime_mono_to_real((ktime_t){ .tv64 = 0 });
+ ctx->moffs = ktime_mono_to_real(0);
return true;
}
static void timerfd_setup_cancel(struct timerfd_ctx *ctx, int flags)
{
+ spin_lock(&ctx->cancel_lock);
if ((ctx->clockid == CLOCK_REALTIME ||
ctx->clockid == CLOCK_REALTIME_ALARM) &&
(flags & TFD_TIMER_ABSTIME) && (flags & TFD_TIMER_CANCEL_ON_SET)) {
@@ -141,9 +150,10 @@ static void timerfd_setup_cancel(struct timerfd_ctx *ctx, int flags)
list_add_rcu(&ctx->clist, &cancel_list);
spin_unlock(&cancel_lock);
}
- } else if (ctx->might_cancel) {
- timerfd_remove_cancel(ctx);
+ } else {
+ __timerfd_remove_cancel(ctx);
}
+ spin_unlock(&ctx->cancel_lock);
}
static ktime_t timerfd_get_remaining(struct timerfd_ctx *ctx)
@@ -155,7 +165,7 @@ static ktime_t timerfd_get_remaining(struct timerfd_ctx *ctx)
else
remaining = hrtimer_expires_remaining_adjusted(&ctx->t.tmr);
- return remaining.tv64 < 0 ? ktime_set(0, 0): remaining;
+ return remaining < 0 ? 0: remaining;
}
static int timerfd_setup(struct timerfd_ctx *ctx, int flags,
@@ -184,7 +194,7 @@ static int timerfd_setup(struct timerfd_ctx *ctx, int flags,
ctx->t.tmr.function = timerfd_tmrproc;
}
- if (texp.tv64 != 0) {
+ if (texp != 0) {
if (isalarm(ctx)) {
if (flags & TFD_TIMER_ABSTIME)
alarm_start(&ctx->t.alarm, texp);
@@ -261,9 +271,9 @@ static ssize_t timerfd_read(struct file *file, char __user *buf, size_t count,
if (ctx->ticks) {
ticks = ctx->ticks;
- if (ctx->expired && ctx->tintv.tv64) {
+ if (ctx->expired && ctx->tintv) {
/*
- * If tintv.tv64 != 0, this is a periodic timer that
+ * If tintv != 0, this is a periodic timer that
* needs to be re-armed. We avoid doing it in the timer
* callback to avoid DoS attacks specifying a very
* short timer period.
@@ -390,9 +400,9 @@ SYSCALL_DEFINE2(timerfd_create, int, clockid, int, flags)
clockid != CLOCK_BOOTTIME_ALARM))
return -EINVAL;
- if (!capable(CAP_WAKE_ALARM) &&
- (clockid == CLOCK_REALTIME_ALARM ||
- clockid == CLOCK_BOOTTIME_ALARM))
+ if ((clockid == CLOCK_REALTIME_ALARM ||
+ clockid == CLOCK_BOOTTIME_ALARM) &&
+ !capable(CAP_WAKE_ALARM))
return -EPERM;
ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
@@ -400,6 +410,7 @@ SYSCALL_DEFINE2(timerfd_create, int, clockid, int, flags)
return -ENOMEM;
init_waitqueue_head(&ctx->wqh);
+ spin_lock_init(&ctx->cancel_lock);
ctx->clockid = clockid;
if (isalarm(ctx))
@@ -410,7 +421,7 @@ SYSCALL_DEFINE2(timerfd_create, int, clockid, int, flags)
else
hrtimer_init(&ctx->t.tmr, clockid, HRTIMER_MODE_ABS);
- ctx->moffs = ktime_mono_to_real((ktime_t){ .tv64 = 0 });
+ ctx->moffs = ktime_mono_to_real(0);
ufd = anon_inode_getfd("[timerfd]", &timerfd_fops, ctx,
O_RDWR | (flags & TFD_SHARED_FCNTL_FLAGS));
@@ -438,7 +449,7 @@ static int do_timerfd_settime(int ufd, int flags,
return ret;
ctx = f.file->private_data;
- if (!capable(CAP_WAKE_ALARM) && isalarm(ctx)) {
+ if (isalarm(ctx) && !capable(CAP_WAKE_ALARM)) {
fdput(f);
return -EPERM;
}
@@ -469,7 +480,7 @@ static int do_timerfd_settime(int ufd, int flags,
* We do not update "ticks" and "expired" since the timer will be
* re-programmed again in the following timerfd_setup() call.
*/
- if (ctx->expired && ctx->tintv.tv64) {
+ if (ctx->expired && ctx->tintv) {
if (isalarm(ctx))
alarm_forward_now(&ctx->t.alarm, ctx->tintv);
else
@@ -499,7 +510,7 @@ static int do_timerfd_gettime(int ufd, struct itimerspec *t)
ctx = f.file->private_data;
spin_lock_irq(&ctx->wqh.lock);
- if (ctx->expired && ctx->tintv.tv64) {
+ if (ctx->expired && ctx->tintv) {
ctx->expired = 0;
if (isalarm(ctx)) {
generated by cgit v1.2.3 (git 2.46.0) at 2025-08-11 03:45:47 +0000