This is a note to let you know that I've just added the patch titled
x86/mce: Mark mce_end() noinstr
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
x86-mce-mark-mce_end-noinstr.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 21effeac6c232f260c1a54bcdedc676bc5825e43
Author: Borislav Petkov <bp@xxxxxxx>
Date: Mon Nov 1 16:43:33 2021 +0100
x86/mce: Mark mce_end() noinstr
[ 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>
diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index 64d8a96a2bf1e..2a608f0819765 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -1070,10 +1070,13 @@ 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;
@@ -1117,7 +1120,8 @@ static int mce_end(int order)
/*
* Don't reset anything. That's done by the Monarch.
*/
- return 0;
+ ret = 0;
+ goto out;
}
/*
@@ -1132,6 +1136,10 @@ static int mce_end(int order)
* Let others run again.
*/
atomic_set(&mce_executing, 0);
+
+out:
+ instrumentation_end();
+
return ret;
}
