2 files changed, 60 insertions, 4 deletions

diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index 5c423c4bab68..3d6e1bfa4f9d 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -1250,14 +1250,19 @@ static void kill_me_maybe(struct callback_head *cb)
 	if (!p->mce_ripv)
 		flags |= MF_MUST_KILL;
 
-	if (!memory_failure(p->mce_addr >> PAGE_SHIFT, flags)) {
+	if (!memory_failure(p->mce_addr >> PAGE_SHIFT, flags) &&
+	    !(p->mce_kflags & MCE_IN_KERNEL_COPYIN)) {
 		set_mce_nospec(p->mce_addr >> PAGE_SHIFT, p->mce_whole_page);
 		sync_core();
 		return;
 	}
 
-	pr_err("Memory error not recovered");
-	kill_me_now(cb);
+	if (p->mce_vaddr != (void __user *)-1l) {
+		force_sig_mceerr(BUS_MCEERR_AR, p->mce_vaddr, PAGE_SHIFT);
+	} else {
+		pr_err("Memory error not recovered");
+		kill_me_now(cb);
+	}
 }
 
 static void queue_task_work(struct mce *m, int kill_it)
diff --git a/arch/x86/kernel/cpu/mce/severity.c b/arch/x86/kernel/cpu/mce/severity.c
index c6494e6579c1..83df991314c5 100644
--- a/arch/x86/kernel/cpu/mce/severity.c
+++ b/arch/x86/kernel/cpu/mce/severity.c
@@ -13,6 +13,9 @@
 
 #include <asm/mce.h>
 #include <asm/intel-family.h>
+#include <asm/traps.h>
+#include <asm/insn.h>
+#include <asm/insn-eval.h>
 
 #include "internal.h"
 
@@ -212,6 +215,47 @@ static struct severity {
 #define mc_recoverable(mcg) (((mcg) & (MCG_STATUS_RIPV|MCG_STATUS_EIPV)) == \
 				(MCG_STATUS_RIPV|MCG_STATUS_EIPV))
 
+static bool is_copy_from_user(struct pt_regs *regs)
+{
+	u8 insn_buf[MAX_INSN_SIZE];
+	struct insn insn;
+	unsigned long addr;
+
+	if (copy_from_kernel_nofault(insn_buf, (void *)regs->ip, MAX_INSN_SIZE))
+		return false;
+
+	kernel_insn_init(&insn, insn_buf, MAX_INSN_SIZE);
+	insn_get_opcode(&insn);
+	if (!insn.opcode.got)
+		return false;
+
+	switch (insn.opcode.value) {
+	/* MOV mem,reg */
+	case 0x8A: case 0x8B:
+	/* MOVZ mem,reg */
+	case 0xB60F: case 0xB70F:
+		insn_get_modrm(&insn);
+		insn_get_sib(&insn);
+		if (!insn.modrm.got || !insn.sib.got)
+			return false;
+		addr = (unsigned long)insn_get_addr_ref(&insn, regs);
+		break;
+	/* REP MOVS */
+	case 0xA4: case 0xA5:
+		addr = regs->si;
+		break;
+	default:
+		return false;
+	}
+
+	if (fault_in_kernel_space(addr))
+		return false;
+
+	current->mce_vaddr = (void __user *)addr;
+
+	return true;
+}
+
 /*
  * If mcgstatus indicated that ip/cs on the stack were
  * no good, then "m->cs" will be zero and we will have
@@ -229,10 +273,17 @@ static int error_context(struct mce *m, struct pt_regs *regs)
 
 	if ((m->cs & 3) == 3)
 		return IN_USER;
+	if (!mc_recoverable(m->mcgstatus))
+		return IN_KERNEL;
 
 	t = ex_get_fault_handler_type(m->ip);
-	if (mc_recoverable(m->mcgstatus) && t == EX_HANDLER_FAULT) {
+	if (t == EX_HANDLER_FAULT) {
+		m->kflags |= MCE_IN_KERNEL_RECOV;
+		return IN_KERNEL_RECOV;
+	}
+	if (t == EX_HANDLER_UACCESS && regs && is_copy_from_user(regs)) {
 		m->kflags |= MCE_IN_KERNEL_RECOV;
+		m->kflags |= MCE_IN_KERNEL_COPYIN;
 		return IN_KERNEL_RECOV;
 	}