From: Gabriele Paoloni <gabriele.paol...@intel.com>

[ Upstream commit e273e6e12ab1db3eb57712bd60655744d0091fa3 ]

Right now, for local MCEs the machine calls panic(), if needed, right
after lmce is set. For MCE broadcasting, mce_reign() takes care of
calling mce_panic().

Hence:
- improve readability by moving the conditional evaluation of
tolerant up to when kill_it is set first;
- move the mce_panic() call up into the statement where mce_end()
fails.

 [ bp: Massage, remove comment in the mce_end() failure case because it
   is superfluous; use local ptr 'cfg' in both tests. ]

Signed-off-by: Gabriele Paoloni <gabriele.paol...@intel.com>
Signed-off-by: Borislav Petkov <b...@suse.de>
Reviewed-by: Tony Luck <tony.l...@intel.com>
Link: 
https://lkml.kernel.org/r/20201127161819.3106432-3-gabriele.paol...@intel.com
Signed-off-by: Sasha Levin <sas...@kernel.org>
---
 arch/x86/kernel/cpu/mce/core.c | 15 ++++-----------
 1 file changed, 4 insertions(+), 11 deletions(-)

diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index c2a9762d278dd..10f69e045d3ea 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -1328,8 +1328,7 @@ void do_machine_check(struct pt_regs *regs, long 
error_code)
         * severity is MCE_AR_SEVERITY we have other options.
         */
        if (!(m.mcgstatus & MCG_STATUS_RIPV))
-               kill_it = 1;
-
+               kill_it = (cfg->tolerant == 3) ? 0 : 1;
        /*
         * Check if this MCE is signaled to only this logical processor,
         * on Intel only.
@@ -1364,6 +1363,9 @@ void do_machine_check(struct pt_regs *regs, long 
error_code)
                if (mce_end(order) < 0) {
                        if (!no_way_out)
                                no_way_out = worst >= MCE_PANIC_SEVERITY;
+
+                       if (no_way_out && cfg->tolerant < 3)
+                               mce_panic("Fatal machine check on current CPU", 
&m, msg);
                }
        } else {
                /*
@@ -1380,15 +1382,6 @@ void do_machine_check(struct pt_regs *regs, long 
error_code)
                }
        }
 
-       /*
-        * If tolerant is at an insane level we drop requests to kill
-        * processes and continue even when there is no way out.
-        */
-       if (cfg->tolerant == 3)
-               kill_it = 0;
-       else if (no_way_out)
-               mce_panic("Fatal machine check on current CPU", &m, msg);
-
        if (worst > 0)
                irq_work_queue(&mce_irq_work);
 
-- 
2.27.0

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