[PATCH v0 12/12] x86/mce: Mark mce_start() noinstr

Borislav Petkov
2021-11-04T14:41:15Z

vmlinux.o: warning: objtool: do_machine_check()+0x4ae: call to __const_udelay() leaves .noinstr.text section

Signed-off-by: Borislav Petkov <bp@suse.de>
---
arch/x86/kernel/cpu/mce/core.c | 19 +++++++++++++------
1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index bc97db90ac0a..4bec85a07259 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -1002,13 +1002,13 @@ static atomic_t global_nwo;
* in the entry order.
* TBD double check parallel CPU hotunplug
*/
-static int mce_start(int *no_way_out)
+static noinstr int mce_start(int *no_way_out)
{
- int order;
u64 timeout = (u64)mca_cfg.monarch_timeout * NSEC_PER_USEC;
+ int order, ret = -1;

if (!timeout)
- return -1;
+ return ret;

atomic_add(*no_way_out, &global_nwo);
/*
@@ -1018,6 +1018,8 @@ static int mce_start(int *no_way_out)
order = atomic_inc_return(&mce_callin);
cpumask_clear_cpu(smp_processor_id(), &mce_missing_cpus);

+ instrumentation_begin();
+
/*
* Wait for everyone.
*/
@@ -1025,7 +1027,7 @@ static int mce_start(int *no_way_out)
if (mce_timed_out(&timeout,
"Timeout: Not all CPUs entered broadcast exception handler")) {
atomic_set(&global_nwo, 0);
- return -1;
+ goto out;
}
ndelay(SPINUNIT);
}
@@ -1051,7 +1053,7 @@ static int mce_start(int *no_way_out)
if (mce_timed_out(&timeout,
"Timeout: Subject CPUs unable to finish machine check processing")) {
atomic_set(&global_nwo, 0);
- return -1;
+ goto out;
}
ndelay(SPINUNIT);
}
@@ -1062,7 +1064,12 @@ static int mce_start(int *no_way_out)
*/
*no_way_out = atomic_read(&global_nwo);

- return order;
+ ret = order;
+
+out:
+ instrumentation_end();
+
+ return ret;
}

/*
--
2.29.2