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| author | Zong Li <zong.li@sifive.com> | 2020-10-21 10:38:39 +0300 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2020-10-26 14:12:27 +0300 |
| commit | 4230e2deaa484b385aa01d598b2aea8e7f2660a6 (patch) | |
| tree | c542bc412a1c1769616b3f857ac8cc396d0674b0 | |
| parent | 3650b228f83adda7e5ee532e2b90429c03f7b9ec (diff) | |
| download | linux-4230e2deaa484b385aa01d598b2aea8e7f2660a6.tar.xz | |
stop_machine, rcu: Mark functions as notrace
Some architectures assume that the stopped CPUs don't make function calls
to traceable functions when they are in the stopped state. See also commit
cb9d7fd51d9f ("watchdog: Mark watchdog touch functions as notrace").
Violating this assumption causes kernel crashes when switching tracer on
RISC-V.
Mark rcu_momentary_dyntick_idle() and stop_machine_yield() notrace to
prevent this.
Fixes: 4ecf0a43e729 ("processor: get rid of cpu_relax_yield")
Fixes: 366237e7b083 ("stop_machine: Provide RCU quiescent state in multi_cpu_stop()")
Signed-off-by: Zong Li <zong.li@sifive.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Atish Patra <atish.patra@wdc.com>
Tested-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20201021073839.43935-1-zong.li@sifive.com
| -rw-r--r-- | kernel/rcu/tree.c | 2 | ||||
| -rw-r--r-- | kernel/stop_machine.c | 2 |
2 files changed, 2 insertions, 2 deletions
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 06895ef85d69..2a52f42f64b6 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -409,7 +409,7 @@ bool rcu_eqs_special_set(int cpu) * * The caller must have disabled interrupts and must not be idle. */ -void rcu_momentary_dyntick_idle(void) +notrace void rcu_momentary_dyntick_idle(void) { int special; diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c index 865bb0228ab6..890b79cf0e7c 100644 --- a/kernel/stop_machine.c +++ b/kernel/stop_machine.c @@ -178,7 +178,7 @@ static void ack_state(struct multi_stop_data *msdata) set_state(msdata, msdata->state + 1); } -void __weak stop_machine_yield(const struct cpumask *cpumask) +notrace void __weak stop_machine_yield(const struct cpumask *cpumask) { cpu_relax(); } |