From 4cd2bb12981165f865d2b8ed92b446b52310ef74 Mon Sep 17 00:00:00 2001
From: Quanyang Wang <quanyang.wang@windriver.com>
Date: Tue, 29 Sep 2020 16:20:27 +0800
Subject: [PATCH 1/4] time/sched_clock: Mark sched_clock_read_begin/retry() as
notrace
Since sched_clock_read_begin() and sched_clock_read_retry() are called
by notrace function sched_clock(), they shouldn't be traceable either,
or else ftrace_graph_caller will run into a dead loop on the path
as below (arm for instance):
ftrace_graph_caller()
prepare_ftrace_return()
function_graph_enter()
ftrace_push_return_trace()
trace_clock_local()
sched_clock()
sched_clock_read_begin/retry()
Fixes: 1b86abc1c645 ("sched_clock: Expose struct clock_read_data")
Signed-off-by: Quanyang Wang <quanyang.wang@windriver.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200929082027.16787-1-quanyang.wang@windriver.com
---
kernel/time/sched_clock.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/time/sched_clock.c b/kernel/time/sched_clock.c
index 0642013dace4..b1b9b12899f5 100644
--- a/kernel/time/sched_clock.c
+++ b/kernel/time/sched_clock.c
@@ -68,13 +68,13 @@ static inline u64 notrace cyc_to_ns(u64 cyc, u32 mult, u32 shift)
return (cyc * mult) >> shift;
}
-struct clock_read_data *sched_clock_read_begin(unsigned int *seq)
+notrace struct clock_read_data *sched_clock_read_begin(unsigned int *seq)
{
*seq = raw_read_seqcount_latch(&cd.seq);
return cd.read_data + (*seq & 1);
}
-int sched_clock_read_retry(unsigned int seq)
+notrace int sched_clock_read_retry(unsigned int seq)
{
return read_seqcount_latch_retry(&cd.seq, seq);
}
From 5254cb87c0423f73c8036235795788a132e8956e Mon Sep 17 00:00:00 2001
From: YueHaibing <yuehaibing@huawei.com>
Date: Wed, 9 Sep 2020 21:48:50 +0800
Subject: [PATCH 2/4] hrtimer: Remove unused inline function
debug_hrtimer_free()
There is no caller in tree, remove it.
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20200909134850.21940-1-yuehaibing@huawei.com
---
kernel/time/hrtimer.c | 5 -----
1 file changed, 5 deletions(-)
diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
index 3624b9b5835d..387b4bef7dd1 100644
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c
@@ -425,11 +425,6 @@ static inline void debug_hrtimer_deactivate(struct hrtimer *timer)
debug_object_deactivate(timer, &hrtimer_debug_descr);
}
-static inline void debug_hrtimer_free(struct hrtimer *timer)
-{
- debug_object_free(timer, &hrtimer_debug_descr);
-}
-
static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
enum hrtimer_mode mode);
From 9010e3876e1c3f7b1c3769bee519d6a871589aca Mon Sep 17 00:00:00 2001
From: YueHaibing <yuehaibing@huawei.com>
Date: Wed, 9 Sep 2020 21:47:49 +0800
Subject: [PATCH 3/4] timers: Remove unused inline funtion debug_timer_free()
There is no caller in tree, remove it.
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20200909134749.32300-1-yuehaibing@huawei.com
---
kernel/time/timer.c | 5 -----
1 file changed, 5 deletions(-)
diff --git a/kernel/time/timer.c b/kernel/time/timer.c
index de37e33a868d..c3ad64fb9d8b 100644
--- a/kernel/time/timer.c
+++ b/kernel/time/timer.c
@@ -732,11 +732,6 @@ static inline void debug_timer_deactivate(struct timer_list *timer)
debug_object_deactivate(timer, &timer_debug_descr);
}
-static inline void debug_timer_free(struct timer_list *timer)
-{
- debug_object_free(timer, &timer_debug_descr);
-}
-
static inline void debug_timer_assert_init(struct timer_list *timer)
{
debug_object_assert_init(timer, &timer_debug_descr);
From cb47755725da7b90fecbb2aa82ac3b24a7adb89b Mon Sep 17 00:00:00 2001
From: Zeng Tao <prime.zeng@hisilicon.com>
Date: Tue, 1 Sep 2020 17:30:13 +0800
Subject: [PATCH 4/4] time: Prevent undefined behaviour in timespec64_to_ns()
UBSAN reports:
Undefined behaviour in ./include/linux/time64.h:127:27
signed integer overflow:
17179869187 * 1000000000 cannot be represented in type 'long long int'
Call Trace:
timespec64_to_ns include/linux/time64.h:127 [inline]
set_cpu_itimer+0x65c/0x880 kernel/time/itimer.c:180
do_setitimer+0x8e/0x740 kernel/time/itimer.c:245
__x64_sys_setitimer+0x14c/0x2c0 kernel/time/itimer.c:336
do_syscall_64+0xa1/0x540 arch/x86/entry/common.c:295
Commit bd40a175769d ("y2038: itimer: change implementation to timespec64")
replaced the original conversion which handled time clamping correctly with
timespec64_to_ns() which has no overflow protection.
Fix it in timespec64_to_ns() as this is not necessarily limited to the
usage in itimers.
[ tglx: Added comment and adjusted the fixes tag ]
Fixes: 361a3bf00582 ("time64: Add time64.h header and define struct timespec64")
Signed-off-by: Zeng Tao <prime.zeng@hisilicon.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/1598952616-6416-1-git-send-email-prime.zeng@hisilicon.com
---
include/linux/time64.h | 4 ++++
kernel/time/itimer.c | 4 ----
2 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/include/linux/time64.h b/include/linux/time64.h
index c9dcb3e5781f..5117cb5b5656 100644
--- a/include/linux/time64.h
+++ b/include/linux/time64.h
@@ -124,6 +124,10 @@ static inline bool timespec64_valid_settod(const struct timespec64 *ts)
*/
static inline s64 timespec64_to_ns(const struct timespec64 *ts)
{
+ /* Prevent multiplication overflow */
+ if ((unsigned long long)ts->tv_sec >= KTIME_SEC_MAX)
+ return KTIME_MAX;
+
return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
}
diff --git a/kernel/time/itimer.c b/kernel/time/itimer.c
index ca4e6d57d68b..00629e658ca1 100644
--- a/kernel/time/itimer.c
+++ b/kernel/time/itimer.c
@@ -172,10 +172,6 @@ static void set_cpu_itimer(struct task_struct *tsk, unsigned int clock_id,
u64 oval, nval, ointerval, ninterval;
struct cpu_itimer *it = &tsk->signal->it[clock_id];
- /*
- * Use the to_ktime conversion because that clamps the maximum
- * value to KTIME_MAX and avoid multiplication overflows.
- */
nval = timespec64_to_ns(&value->it_value);
ninterval = timespec64_to_ns(&value->it_interval);