[PATCH AUTOSEL 4.19 13/79] powerpc/pseries: Mark accumulate_stolen_time() as notrace

Sasha Levin
2019-12-11T15:46:04Z

From: Michael Ellerman <mpe@ellerman.id.au>

[ Upstream commit eb8e20f89093b64f48975c74ccb114e6775cee22 ]

accumulate_stolen_time() is called prior to interrupt state being
reconciled, which can trip the warning in arch_local_irq_restore():

WARNING: CPU: 5 PID: 1017 at arch/powerpc/kernel/irq.c:258 .arch_local_irq_restore+0x9c/0x130
...
NIP .arch_local_irq_restore+0x9c/0x130
LR .rb_start_commit+0x38/0x80
Call Trace:
.ring_buffer_lock_reserve+0xe4/0x620
.trace_function+0x44/0x210
.function_trace_call+0x148/0x170
.ftrace_ops_no_ops+0x180/0x1d0
ftrace_call+0x4/0x8
.accumulate_stolen_time+0x1c/0xb0
decrementer_common+0x124/0x160

For now just mark it as notrace. We may change the ordering to call it
after interrupt state has been reconciled, but that is a larger
change.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191024055932.27940-1-mpe@ellerman.id.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/powerpc/kernel/time.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index 7707990c4c169..02ae92c224800 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -235,7 +235,7 @@ static u64 scan_dispatch_log(u64 stop_tb)
* Accumulate stolen time by scanning the dispatch trace log.
* Called on entry from user mode.
*/
-void accumulate_stolen_time(void)
+void notrace accumulate_stolen_time(void)
{
u64 sst, ust;
unsigned long save_irq_soft_mask = irq_soft_mask_return();
--
2.20.1