[PATCH AUTOSEL 5.4 35/73] x86/mce: Mark mce_end() noinstr

From: Sasha Levin
Date: Mon Jan 17 2022 - 22:16:20 EST


From: Borislav Petkov <bp@xxxxxxx>

[ Upstream commit b4813539d37fa31fed62cdfab7bd2dd8929c5b2e ]

It is called by the #MC handler which is noinstr.

Fixes

vmlinux.o: warning: objtool: do_machine_check()+0xbd6: call to memset() leaves .noinstr.text section

Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Link: https://lore.kernel.org/r/20211208111343.8130-9-bp@xxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
arch/x86/kernel/cpu/mce/core.c | 14 +++++++++++---
1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index 290d64e04ab20..a0f6c574c3783 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -1080,10 +1080,13 @@ static int mce_start(int *no_way_out)
* Synchronize between CPUs after main scanning loop.
* This invokes the bulk of the Monarch processing.
*/
-static int mce_end(int order)
+static noinstr int mce_end(int order)
{
- int ret = -1;
u64 timeout = (u64)mca_cfg.monarch_timeout * NSEC_PER_USEC;
+ int ret = -1;
+
+ /* Allow instrumentation around external facilities. */
+ instrumentation_begin();

if (!timeout)
goto reset;
@@ -1127,7 +1130,8 @@ static int mce_end(int order)
/*
* Don't reset anything. That's done by the Monarch.
*/
- return 0;
+ ret = 0;
+ goto out;
}

/*
@@ -1142,6 +1146,10 @@ static int mce_end(int order)
* Let others run again.
*/
atomic_set(&mce_executing, 0);
+
+out:
+ instrumentation_end();
+
return ret;
}

--
2.34.1