[PATCH v2 2/5] x86/mce: move the mce_panic() call and 'kill_it' assignments to the right places

From: Gabriele Paoloni
Date: Fri Nov 27 2020 - 11:18:42 EST


Right now for local MCEs we panic(),if needed, right after lmce is
set. For global MCEs mce_reign() takes care of calling mce_panic().
Hence:
- improve readibility 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.

Signed-off-by: Gabriele Paoloni <gabriele.paoloni@xxxxxxxxx>
Reviewed-by: Tony Luck <tony.luck@xxxxxxxxx>
---
arch/x86/kernel/cpu/mce/core.c | 18 +++++++-----------
1 file changed, 7 insertions(+), 11 deletions(-)

diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index 32b7099e3511..50e9b0893a92 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -1350,8 +1350,7 @@ noinstr void do_machine_check(struct pt_regs *regs)
* 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, Zhaoxin only.
@@ -1387,6 +1386,12 @@ noinstr void do_machine_check(struct pt_regs *regs)
if (mce_end(order) < 0) {
if (!no_way_out)
no_way_out = worst >= MCE_PANIC_SEVERITY;
+ /*
+ * mce_reign() has probably failed hence evaluate if we need
+ * to panic
+ */
+ if (no_way_out && mca_cfg.tolerant < 3)
+ mce_panic("Fatal machine check on current CPU", &m, msg);
}
} else {
/*
@@ -1403,15 +1408,6 @@ noinstr void do_machine_check(struct pt_regs *regs)
}
}

- /*
- * 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);

--
2.20.1

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