Re: [PATCH] x86/mce: Save microcode revision in machine check records

[Borislav Petkov]

On Thu, Mar 01, 2018 at 11:40:31PM +, Luck, Tony wrote:
> + c = _data(m->cpu);
> 
> Bother. Breaks on systems with >255 cpus because "cpu" is __u8.

No worries, I committed an even better version:

---
From: Tony Luck 
Date: Thu, 1 Mar 2018 15:34:49 -0800
Subject: [PATCH] x86/MCE: Save microcode revision in machine check records

Updating microcode used to be relatively rare. Now that it has become
more common we should save the microcode version in a machine check
record to make sure that those people looking at the error have this
important information bundled with the rest of the logged information.

Signed-off-by: Tony Luck 
Cc: Yazen Ghannam 
Cc: linux-edac 
Cc: x86-ml 
Link: http://lkml.kernel.org/r/20180301233449.24311-1-tony.l...@intel.com
[ Simplify a bit. ]
Signed-off-by: Borislav Petkov 
---
 arch/x86/include/uapi/asm/mce.h  | 1 +
 arch/x86/kernel/cpu/mcheck/mce.c | 4 +++-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/uapi/asm/mce.h b/arch/x86/include/uapi/asm/mce.h
index 91723461dc1f..435db58a7bad 100644
--- a/arch/x86/include/uapi/asm/mce.h
+++ b/arch/x86/include/uapi/asm/mce.h
@@ -30,6 +30,7 @@ struct mce {
__u64 synd; /* MCA_SYND MSR: only valid on SMCA systems */
__u64 ipid; /* MCA_IPID MSR: only valid on SMCA systems */
__u64 ppin; /* Protected Processor Inventory Number */
+   __u32 microcode;/* Microcode revision */
 };
 
 #define MCE_GET_RECORD_LEN   _IOR('M', 1, int)
diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index 3c9a25b93538..181f6cf25895 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -130,6 +130,8 @@ void mce_setup(struct mce *m)
 
if (this_cpu_has(X86_FEATURE_INTEL_PPIN))
rdmsrl(MSR_PPIN, m->ppin);
+
+   m->microcode = boot_cpu_data.microcode;
 }
 
 DEFINE_PER_CPU(struct mce, injectm);
@@ -262,7 +264,7 @@ static void __print_mce(struct mce *m)
 */
pr_emerg(HW_ERR "PROCESSOR %u:%x TIME %llu SOCKET %u APIC %x microcode 
%x\n",
m->cpuvendor, m->cpuid, m->time, m->socketid, m->apicid,
-   cpu_data(m->extcpu).microcode);
+   m->microcode);
 }
 
 static void print_mce(struct mce *m)
-- 
2.13.0

-- 
Regards/Gruss,
Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.

Re: [PATCH] x86/mce: Save microcode revision in machine check records

[Borislav Petkov]

On Thu, Mar 01, 2018 at 11:40:31PM +, Luck, Tony wrote:
> + c = _data(m->cpu);
> 
> Bother. Breaks on systems with >255 cpus because "cpu" is __u8.

No worries, I committed an even better version:

---
From: Tony Luck 
Date: Thu, 1 Mar 2018 15:34:49 -0800
Subject: [PATCH] x86/MCE: Save microcode revision in machine check records

Updating microcode used to be relatively rare. Now that it has become
more common we should save the microcode version in a machine check
record to make sure that those people looking at the error have this
important information bundled with the rest of the logged information.

Signed-off-by: Tony Luck 
Cc: Yazen Ghannam 
Cc: linux-edac 
Cc: x86-ml 
Link: http://lkml.kernel.org/r/20180301233449.24311-1-tony.l...@intel.com
[ Simplify a bit. ]
Signed-off-by: Borislav Petkov 
---
 arch/x86/include/uapi/asm/mce.h  | 1 +
 arch/x86/kernel/cpu/mcheck/mce.c | 4 +++-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/uapi/asm/mce.h b/arch/x86/include/uapi/asm/mce.h
index 91723461dc1f..435db58a7bad 100644
--- a/arch/x86/include/uapi/asm/mce.h
+++ b/arch/x86/include/uapi/asm/mce.h
@@ -30,6 +30,7 @@ struct mce {
__u64 synd; /* MCA_SYND MSR: only valid on SMCA systems */
__u64 ipid; /* MCA_IPID MSR: only valid on SMCA systems */
__u64 ppin; /* Protected Processor Inventory Number */
+   __u32 microcode;/* Microcode revision */
 };
 
 #define MCE_GET_RECORD_LEN   _IOR('M', 1, int)
diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index 3c9a25b93538..181f6cf25895 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -130,6 +130,8 @@ void mce_setup(struct mce *m)
 
if (this_cpu_has(X86_FEATURE_INTEL_PPIN))
rdmsrl(MSR_PPIN, m->ppin);
+
+   m->microcode = boot_cpu_data.microcode;
 }
 
 DEFINE_PER_CPU(struct mce, injectm);
@@ -262,7 +264,7 @@ static void __print_mce(struct mce *m)
 */
pr_emerg(HW_ERR "PROCESSOR %u:%x TIME %llu SOCKET %u APIC %x microcode 
%x\n",
m->cpuvendor, m->cpuid, m->time, m->socketid, m->apicid,
-   cpu_data(m->extcpu).microcode);
+   m->microcode);
 }
 
 static void print_mce(struct mce *m)
-- 
2.13.0

-- 
Regards/Gruss,
Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.

RE: [PATCH] x86/mce: Save microcode revision in machine check records

[Luck, Tony]

+   c = _data(m->cpu);

Bother. Breaks on systems with >255 cpus because "cpu" is __u8.

s/m->cpu/m->extcpu/

-Tony

RE: [PATCH] x86/mce: Save microcode revision in machine check records

[Luck, Tony]

+   c = _data(m->cpu);

Bother. Breaks on systems with >255 cpus because "cpu" is __u8.

s/m->cpu/m->extcpu/

-Tony