From: Borislav Petkov <bp@suse.de> stable inclusion from stable-v5.10.94 commit f21ca973b43fb23416bd89dc267aa51249c20afb bugzilla: https://gitee.com/openeuler/kernel/issues/I531X9 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit 3c7ce80a818fa7950be123cac80cd078e5ac1013 ] And allow instrumentation inside it because it does calls to other facilities which will not be tagged noinstr. Fixes vmlinux.o: warning: objtool: do_machine_check()+0xc73: call to mce_panic() leaves .noinstr.text section Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20211208111343.8130-8-bp@alien8.de Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> Acked-by: Xie XiuQi <xiexiuqi@huawei.com> --- arch/x86/kernel/cpu/mce/core.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c index 9e6cd52df92e..e86caf264a2a 100644 --- a/arch/x86/kernel/cpu/mce/core.c +++ b/arch/x86/kernel/cpu/mce/core.c @@ -295,11 +295,17 @@ static void wait_for_panic(void) panic("Panicing machine check CPU died"); } -static void mce_panic(const char *msg, struct mce *final, char *exp) +static noinstr void mce_panic(const char *msg, struct mce *final, char *exp) { - int apei_err = 0; struct llist_node *pending; struct mce_evt_llist *l; + int apei_err = 0; + + /* + * Allow instrumentation around external facilities usage. Not that it + * matters a whole lot since the machine is going to panic anyway. + */ + instrumentation_begin(); if (!fake_panic) { /* @@ -314,7 +320,7 @@ static void mce_panic(const char *msg, struct mce *final, char *exp) } else { /* Don't log too much for fake panic */ if (atomic_inc_return(&mce_fake_panicked) > 1) - return; + goto out; } pending = mce_gen_pool_prepare_records(); /* First print corrected ones that are still unlogged */ @@ -352,6 +358,9 @@ static void mce_panic(const char *msg, struct mce *final, char *exp) panic(msg); } else pr_emerg(HW_ERR "Fake kernel panic: %s\n", msg); + +out: + instrumentation_end(); } /* Support code for software error injection */ -- 2.20.1