[PATCH AUTOSEL 4.9 08/42] powerpc/pseries: Mark accumulate_stolen_time() as notrace

From: Sasha Levin
Date: Wed Dec 11 2019 - 10:38:39 EST


From: Michael Ellerman <mpe@xxxxxxxxxxxxxx>

[ 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@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20191024055932.27940-1-mpe@xxxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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 ab7b661b6da3a..412ac5d45160b 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -257,7 +257,7 @@ 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;
u8 save_soft_enabled = local_paca->soft_enabled;
--
2.20.1