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@suse.de>
Link: https://lore.kernel.org/r/20211208111343.8130-9-bp@alien8.de
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index c5a1022463bcc24dd8dcf47305366cad1dfa5a6d..c37a0bcf2744bf8e7c582748292a826d2fc63fe2 100644 (file)
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -1081,10 +1081,13 @@ 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;
@@ -1128,7 +1131,8 @@ static int mce_end(int order)
                /*
                 * Don't reset anything. That's done by the Monarch.
                 */
-               return 0;
+               ret = 0;
+               goto out;
        }
 
        /*
@@ -1144,6 +1148,10 @@ reset:
         * Let others run again.
         */
        atomic_set(&mce_executing, 0);
+
+out:
+       instrumentation_end();
+
        return ret;
 }