linux-kernel - [PATCH AUTOSEL 4.9 35/48] x86/mce: Panic for LMCE only if mca

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Date:   Tue, 22 Dec 2020 21:24:03 -0500
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Gabriele Paoloni <gabriele.paoloni@...el.com>,
        Borislav Petkov <bp@...e.de>, Tony Luck <tony.luck@...el.com>,
        Sasha Levin <sashal@...nel.org>
Subject: [PATCH AUTOSEL 4.9 35/48] x86/mce: Panic for LMCE only if mca_cfg.tolerant < 3

From: Gabriele Paoloni <gabriele.paoloni@...el.com>

[ Upstream commit 3a866b16fd2360a9c4ebf71cfbf7ebfe968c1409 ]

Right now for LMCE, if no_way_out is set, mce_panic() is called
regardless of mca_cfg.tolerant. This is not correct as, if
mca_cfg.tolerant = 3, the code should never panic.

Add that check.

 [ bp: use local ptr 'cfg'. ]

Signed-off-by: Gabriele Paoloni <gabriele.paoloni@...el.com>
Signed-off-by: Borislav Petkov <bp@...e.de>
Reviewed-by: Tony Luck <tony.luck@...el.com>
Link: https://lkml.kernel.org/r/20201127161819.3106432-4-gabriele.paoloni@intel.com
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 arch/x86/kernel/cpu/mcheck/mce.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index 07188a0124922..c0e85ad111de8 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -1182,7 +1182,7 @@ void do_machine_check(struct pt_regs *regs, long error_code)
 	 * to see it will clear it.
 	 */
 	if (lmce) {
-		if (no_way_out)
+		if (no_way_out && cfg->tolerant < 3)
 			mce_panic("Fatal local machine check", &m, msg);
 	} else {
 		order = mce_start(&no_way_out);
-- 
2.27.0