From: Borislav Petkov <bp@alien8.de>
To: "Jan H. Schönherr" <jschoenh@amazon.de>
Cc: Tony Luck <tony.luck@intel.com>,
linux-edac@vger.kernel.org, Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
x86@kernel.org
Subject: Re: [PATCH 4/6] x86/mce: Fix handling of optional message string
Date: Fri, 20 Dec 2019 11:01:06 +0100 [thread overview]
Message-ID: <20191220100106.GB1397@zn.tnic> (raw)
In-Reply-To: <47be6ccd-0387-47c0-6f01-1304ce26780f@amazon.de>
On Thu, Dec 19, 2019 at 06:49:32PM +0100, Jan H. Schönherr wrote:
> Not quite. mce_panic() already handles NULL as a value for "exp" (not "msg").
>
> We still need to pass NULL or a proper pointer. Not some uninitialized, potentially
> random data.
>
> So, at the very least we need to initialize "tmp" in mce_no_way_out(), if you're looking
> for a minimal patch.
Yes, sure, this is what I'm thinking of.
And yes, I'm not going to cry if we don't print the immensely helpful
"Unknown" anymore.</sarcasm>
---
diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index 68dd4b358740..fd23f9f53379 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -798,7 +798,7 @@ EXPORT_SYMBOL_GPL(machine_check_poll);
static int mce_no_way_out(struct mce *m, char **msg, unsigned long *validp,
struct pt_regs *regs)
{
- char *tmp;
+ char *tmp = NULL;
int i;
for (i = 0; i < this_cpu_read(mce_num_banks); i++) {
@@ -1223,8 +1223,8 @@ void do_machine_check(struct pt_regs *regs, long error_code)
DECLARE_BITMAP(toclear, MAX_NR_BANKS);
struct mca_config *cfg = &mca_cfg;
int cpu = smp_processor_id();
- char *msg = "Unknown";
struct mce m, *final;
+ char *msg = NULL;
int worst = 0;
/*
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
next prev parent reply other threads:[~2019-12-20 10:01 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-10 0:07 [PATCH 0/6] x86/mce: Various fixes and cleanups for MCE handling Jan H. Schönherr
2019-12-10 0:07 ` [PATCH 1/6] x86/mce: Take action on UCNA/Deferred errors again Jan H. Schönherr
2019-12-10 0:07 ` [PATCH 2/6] x86/mce: Make mce=nobootlog work again Jan H. Schönherr
2019-12-16 17:15 ` Borislav Petkov
2019-12-10 0:07 ` [PATCH 3/6] x86/mce: Fix possibly incorrect severity calculation on AMD Jan H. Schönherr
2019-12-16 17:26 ` Borislav Petkov
2019-12-16 17:35 ` Ghannam, Yazen
2019-12-10 0:07 ` [PATCH 4/6] x86/mce: Fix handling of optional message string Jan H. Schönherr
2019-12-16 17:37 ` Borislav Petkov
2019-12-19 17:49 ` Jan H. Schönherr
2019-12-20 10:01 ` Borislav Petkov [this message]
2019-12-10 0:07 ` [PATCH 5/6] x86/mce: Pass MCE message to mce_panic() on failed kernel recovery Jan H. Schönherr
2019-12-10 0:07 ` [PATCH 6/6] x86/mce: Remove mce_inject_log() in favor of mce_log() Jan H. Schönherr
2019-12-11 0:25 ` [PATCH 0/6] x86/mce: Various fixes and cleanups for MCE handling Luck, Tony
2019-12-12 12:25 ` Jan H. Schönherr
2019-12-16 16:52 ` Borislav Petkov
2019-12-16 21:59 ` Luck, Tony
2019-12-17 1:19 ` Ghannam, Yazen
2019-12-17 7:34 ` Borislav Petkov
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