[PATCH 3/4] mce-inject: change msr_to_offset() to mce_get_fake_reg()

[Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>]

Introduce mce_get_fake_reg() which returns address of variable for
faked register.

Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
---
 arch/x86/kernel/cpu/mcheck/mce.c |   30 +++++++++++++++---------------
 1 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index 5a6f17d..edd2a82 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -301,20 +301,22 @@ static void mce_panic(char *msg, struct mce *final, char *exp)
 
 /* Support code for software error injection */
 
-static int msr_to_offset(u32 msr)
+static u64 *mce_get_fake_reg(u32 msr)
 {
 	unsigned bank = __get_cpu_var(mce_fake_banks).bank;
+
 	if (msr == rip_msr)
-		return offsetof(struct mce_fake_banks, ip);
+		return &__get_cpu_var(mce_fake_banks).ip;
 	if (msr == MSR_IA32_MCx_STATUS(bank))
-		return offsetof(struct mce_fake_banks, status);
+		return &__get_cpu_var(mce_fake_banks).status;
 	if (msr == MSR_IA32_MCx_ADDR(bank))
-		return offsetof(struct mce_fake_banks, addr);
+		return &__get_cpu_var(mce_fake_banks).addr;
 	if (msr == MSR_IA32_MCx_MISC(bank))
-		return offsetof(struct mce_fake_banks, misc);
+		return &__get_cpu_var(mce_fake_banks).misc;
 	if (msr == MSR_IA32_MCG_STATUS)
-		return offsetof(struct mce_fake_banks, mcgstatus);
-	return -1;
+		return &__get_cpu_var(mce_fake_banks).mcgstatus;
+
+	return NULL;
 }
 
 /* MSR access wrappers used for error injection */
@@ -323,12 +325,11 @@ static u64 mce_rdmsrl(u32 msr)
 	u64 v;
 
 	if (__get_cpu_var(mce_fake_banks).valid) {
-		int offset = msr_to_offset(msr);
-		char *m = (char *)&__get_cpu_var(mce_fake_banks);
+		u64 *reg = mce_get_fake_reg(msr);
 
-		if (offset < 0)
+		if (!reg)
 			return 0;
-		return *(u64 *)(m + offset);
+		return *reg;
 	}
 
 	if (rdmsrl_safe(msr, &v)) {
@@ -347,11 +348,10 @@ static u64 mce_rdmsrl(u32 msr)
 static void mce_wrmsrl(u32 msr, u64 v)
 {
 	if (__get_cpu_var(mce_fake_banks).valid) {
-		int offset = msr_to_offset(msr);
-		char *m = (char *)&__get_cpu_var(mce_fake_banks);
+		u64 *reg = mce_get_fake_reg(msr);
 
-		if (offset >= 0)
-			*(u64 *)(m + offset) = v;
+		if (reg)
+			*reg = v;
 		return;
 	}
 	wrmsrl(msr, v);
-- 
1.6.2.2