[GIT PULL] timer fixes

From: Ingo Molnar
Date: Tue Mar 07 2017 - 20:02:46 EST


Linus,

Please pull the latest timers-urgent-for-linus git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git timers-urgent-for-linus

# HEAD: fa3aa7a54fe6d3abf128f13cd4bbd40eaa48fed2 jiffies: Revert bogus conversion of NSEC_PER_SEC to TICK_NSEC

This includes a fix for lockups caused by incorrect nsecs related cleanup, and a
capabilities check fix for timerfd.

Thanks,

Ingo

------------------>
Frederic Weisbecker (1):
jiffies: Revert bogus conversion of NSEC_PER_SEC to TICK_NSEC

Stephen Smalley (1):
timerfd: Only check CAP_WAKE_ALARM when it is needed


fs/timerfd.c | 8 ++++----
kernel/time/jiffies.c | 2 +-
2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/fs/timerfd.c b/fs/timerfd.c
index 384fa759a563..c543cdb5f8ed 100644
--- a/fs/timerfd.c
+++ b/fs/timerfd.c
@@ -400,9 +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);
@@ -449,7 +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;
}
diff --git a/kernel/time/jiffies.c b/kernel/time/jiffies.c
index 7906b3f0c41a..497719127bf9 100644
--- a/kernel/time/jiffies.c
+++ b/kernel/time/jiffies.c
@@ -125,7 +125,7 @@ int register_refined_jiffies(long cycles_per_second)
shift_hz += cycles_per_tick/2;
do_div(shift_hz, cycles_per_tick);
/* Calculate nsec_per_tick using shift_hz */
- nsec_per_tick = (u64)TICK_NSEC << 8;
+ nsec_per_tick = (u64)NSEC_PER_SEC << 8;
nsec_per_tick += (u32)shift_hz/2;
do_div(nsec_per_tick, (u32)shift_hz);