Patch "x86/MCE: Export memory_error()" has been added to the 4.9-stable tree

This is a note to let you know that I've just added the patch titled

x86/MCE: Export memory_error()

to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
x86-mce-export-memory_error.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Borislav Petkov <[email protected]>
Date: Fri, 19 May 2017 11:39:09 +0200
Subject: x86/MCE: Export memory_error()

From: Borislav Petkov <[email protected]>

commit 2d1f406139ec20320bf38bcd2461aa8e358084b5 upstream.

Export the function which checks whether an MCE is a memory error to other users so that we can reuse the logic. Drop the boot_cpu_data use, while at it, as mce.cpuvendor already has the CPU vendor in there.

Integrate a piece from a patch from Vishal Verma <[email protected]> to export it for modules (nfit).

The main reason we're exporting it is that the nfit handler nfit_handle_mce() needs to detect a memory error properly before doing its recovery actions.

---
 arch/x86/include/asm/mce.h       |    1 +
 arch/x86/kernel/cpu/mcheck/mce.c |   11 +++++------
 2 files changed, 6 insertions(+), 6 deletions(-)

@@ -257,6 +257,7 @@ static inline void mce_amd_feature_init(
 #endif
 
 int mce_available(struct cpuinfo_x86 *c);
+bool mce_is_memory_error(struct mce *m);
 
 DECLARE_PER_CPU(unsigned, mce_exception_count);
 DECLARE_PER_CPU(unsigned, mce_poll_count);

@@ -598,16 +598,14 @@ static void mce_read_aux(struct mce *m,
 	}
 }
 
-static bool memory_error(struct mce *m)
+bool mce_is_memory_error(struct mce *m)
 {
-	struct cpuinfo_x86 *c = &boot_cpu_data;
-
-	if (c->x86_vendor == X86_VENDOR_AMD) {
+	if (m->cpuvendor == X86_VENDOR_AMD) {
 		/* ErrCodeExt[20:16] */
 		u8 xec = (m->status >> 16) & 0x1f;
 
 		return (xec == 0x0 || xec == 0x8);
-	} else if (c->x86_vendor == X86_VENDOR_INTEL) {
+	} else if (m->cpuvendor == X86_VENDOR_INTEL) {
 		/*
 		 * Intel SDM Volume 3B - 15.9.2 Compound Error Codes
 		 *

@@ -628,6 +626,7 @@ static bool memory_error(struct mce *m)
 
 	return false;
 }
+EXPORT_SYMBOL_GPL(mce_is_memory_error);
 
 DEFINE_PER_CPU(unsigned, mce_poll_count);
 

@@ -691,7 +690,7 @@ bool machine_check_poll(enum mcp_flags f
 
 		severity = mce_severity(&m, mca_cfg.tolerant, NULL, false);
 
-		if (severity == MCE_DEFERRED_SEVERITY && memory_error(&m))
+		if (severity == MCE_DEFERRED_SEVERITY && mce_is_memory_error(&m))
 			if (m.status & MCI_STATUS_ADDRV)
 				m.severity = severity;
 

Patches currently in stable-queue which might be from [email protected] are

queue-4.9/x86-mce-export-memory_error.patch queue-4.9/acpi-nfit-fix-the-memory-error-check-in-nfit_handle_mce.patch