From: Borislav Petkov <bp@alien8.de>
To: X86 ML <x86@kernel.org>
Cc: Yazen Ghannam <Yazen.Ghannam@amd.com>,
linux-edac <linux-edac@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: [PATCH 7/7] x86/mce/amd: Make threshold bank setting hotplug robust
Date: Fri, 3 Apr 2020 18:19:43 +0200 [thread overview]
Message-ID: <20200403161943.1458-8-bp@alien8.de> (raw)
In-Reply-To: <20200403161943.1458-1-bp@alien8.de>
From: Thomas Gleixner <tglx@linutronix.de>
Handle the cases when the CPU goes offline before the bank
setting/reading happens.
[ bp: Write commit message. ]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
---
arch/x86/kernel/cpu/mce/amd.c | 14 +++++++++++---
1 file changed, 11 insertions(+), 3 deletions(-)
diff --git a/arch/x86/kernel/cpu/mce/amd.c b/arch/x86/kernel/cpu/mce/amd.c
index 16e7aea86ab1..15c87b87b901 100644
--- a/arch/x86/kernel/cpu/mce/amd.c
+++ b/arch/x86/kernel/cpu/mce/amd.c
@@ -386,6 +386,10 @@ static void threshold_restart_bank(void *_tr)
struct thresh_restart *tr = _tr;
u32 hi, lo;
+ /* sysfs write might race against an offline operation */
+ if (this_cpu_read(threshold_banks))
+ return;
+
rdmsr(tr->b->address, lo, hi);
if (tr->b->threshold_limit < (hi & THRESHOLD_MAX))
@@ -1085,7 +1089,8 @@ store_interrupt_enable(struct threshold_block *b, const char *buf, size_t size)
memset(&tr, 0, sizeof(tr));
tr.b = b;
- smp_call_function_single(b->cpu, threshold_restart_bank, &tr, 1);
+ if (smp_call_function_single(b->cpu, threshold_restart_bank, &tr, 1))
+ return -ENODEV;
return size;
}
@@ -1109,7 +1114,8 @@ store_threshold_limit(struct threshold_block *b, const char *buf, size_t size)
b->threshold_limit = new;
tr.b = b;
- smp_call_function_single(b->cpu, threshold_restart_bank, &tr, 1);
+ if (smp_call_function_single(b->cpu, threshold_restart_bank, &tr, 1))
+ return -ENODEV;
return size;
}
@@ -1118,7 +1124,9 @@ static ssize_t show_error_count(struct threshold_block *b, char *buf)
{
u32 lo, hi;
- rdmsr_on_cpu(b->cpu, b->address, &lo, &hi);
+ /* CPU might be offline by now */
+ if (rdmsr_on_cpu(b->cpu, b->address, &lo, &hi))
+ return -ENODEV;
return sprintf(buf, "%u\n", ((hi & THRESHOLD_MAX) -
(THRESHOLD_MAX - b->threshold_limit)));
--
2.21.0
next prev parent reply other threads:[~2020-04-03 16:20 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-03 16:19 [PATCH 0/7] x86/mce/amd: Fix some CPU hotplug insanity Borislav Petkov
2020-04-03 16:19 ` [PATCH 1/7] x86/mce/amd: Do proper cleanup on error paths Borislav Petkov
2020-04-15 9:49 ` [tip: ras/core] " tip-bot2 for Thomas Gleixner
2020-04-03 16:19 ` [PATCH 2/7] x86/mce/amd: Init thresholding machinery only on relevant vendors Borislav Petkov
2020-04-15 9:49 ` [tip: ras/core] " tip-bot2 for Thomas Gleixner
2020-04-03 16:19 ` [PATCH 3/7] x86/mce/amd: Protect a not-fully initialized bank from the thresholding interrupt Borislav Petkov
2020-04-15 9:49 ` [tip: ras/core] " tip-bot2 for Thomas Gleixner
2020-04-03 16:19 ` [PATCH 4/7] x86/mce/amd: Sanitize thresholding device creation hotplug path Borislav Petkov
2020-04-15 9:49 ` [tip: ras/core] " tip-bot2 for Thomas Gleixner
2020-04-03 16:19 ` [PATCH 5/7] x86/mce/amd: Straighten CPU " Borislav Petkov
2020-04-15 9:49 ` [tip: ras/core] " tip-bot2 for Thomas Gleixner
2020-04-03 16:19 ` [PATCH 6/7] x86/mce/amd: Cleanup threshold device remove path Borislav Petkov
2020-04-15 9:49 ` [tip: ras/core] " tip-bot2 for Thomas Gleixner
2020-04-03 16:19 ` Borislav Petkov [this message]
2020-04-15 9:49 ` [tip: ras/core] x86/mce/amd: Make threshold bank setting hotplug robust tip-bot2 for Thomas Gleixner
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