Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 5.16 0642/1039] x86/mce: Mark mce_panic() noinstr | Date | Mon, 24 Jan 2022 19:40:31 +0100 |
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From: Borislav Petkov <bp@suse.de>
[ 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> --- 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 70ec5685906b2..9a52ec55e0555 100644 --- a/arch/x86/kernel/cpu/mce/core.c +++ b/arch/x86/kernel/cpu/mce/core.c @@ -267,11 +267,17 @@ 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) { /* @@ -286,7 +292,7 @@ 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 */ @@ -324,6 +330,9 @@ 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 */ -- 2.34.1
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