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authorQuanyang Wang <quanyang.wang@windriver.com>2020-09-29 16:20:27 +0800
committerThomas Gleixner <tglx@linutronix.de>2020-10-26 11:34:31 +0100
commit4cd2bb12981165f865d2b8ed92b446b52310ef74 (patch)
tree08fb9d6532324c60665aa40e65806e32c343d8a2 /kernel/time
parent3650b228f83adda7e5ee532e2b90429c03f7b9ec (diff)
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
Diffstat (limited to 'kernel/time')
-rw-r--r--kernel/time/sched_clock.c4
1 files 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);
}