x86: msr: propagate errors from smp_call_function_single()
Propagate error (-ENXIO) from smp_call_function_single(). These
errors can happen when a CPU is unplugged while the MSR driver is
open.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
diff --git a/arch/x86/kernel/msr.c b/arch/x86/kernel/msr.c
index e439380..9c34a10 100644
--- a/arch/x86/kernel/msr.c
+++ b/arch/x86/kernel/msr.c
@@ -79,8 +79,11 @@
for (; count; count -= 8) {
err = rdmsr_safe_on_cpu(cpu, reg, &data[0], &data[1]);
- if (err)
- return -EIO;
+ if (err) {
+ if (err == -EFAULT) /* Fix idiotic error code */
+ err = -EIO;
+ return err;
+ }
if (copy_to_user(tmp, &data, 8))
return -EFAULT;
tmp += 2;
@@ -105,8 +108,11 @@
if (copy_from_user(&data, tmp, 8))
return -EFAULT;
err = wrmsr_safe_on_cpu(cpu, reg, data[0], data[1]);
- if (err)
- return -EIO;
+ if (err) {
+ if (err == -EFAULT) /* Fix idiotic error code */
+ err = -EIO;
+ return err;
+ }
tmp += 2;
}
diff --git a/arch/x86/lib/msr-on-cpu.c b/arch/x86/lib/msr-on-cpu.c
index d5a2b39..01b868b 100644
--- a/arch/x86/lib/msr-on-cpu.c
+++ b/arch/x86/lib/msr-on-cpu.c
@@ -30,10 +30,11 @@
rv.msr_no = msr_no;
if (safe) {
- smp_call_function_single(cpu, __rdmsr_safe_on_cpu, &rv, 1);
- err = rv.err;
+ err = smp_call_function_single(cpu, __rdmsr_safe_on_cpu,
+ &rv, 1);
+ err = err ? err : rv.err;
} else {
- smp_call_function_single(cpu, __rdmsr_on_cpu, &rv, 1);
+ err = smp_call_function_single(cpu, __rdmsr_on_cpu, &rv, 1);
}
*l = rv.l;
*h = rv.h;
@@ -64,23 +65,24 @@
rv.l = l;
rv.h = h;
if (safe) {
- smp_call_function_single(cpu, __wrmsr_safe_on_cpu, &rv, 1);
- err = rv.err;
+ err = smp_call_function_single(cpu, __wrmsr_safe_on_cpu,
+ &rv, 1);
+ err = err ? err : rv.err;
} else {
- smp_call_function_single(cpu, __wrmsr_on_cpu, &rv, 1);
+ err = smp_call_function_single(cpu, __wrmsr_on_cpu, &rv, 1);
}
return err;
}
-void wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
+int wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
{
- _wrmsr_on_cpu(cpu, msr_no, l, h, 0);
+ return _wrmsr_on_cpu(cpu, msr_no, l, h, 0);
}
-void rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
+int rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
{
- _rdmsr_on_cpu(cpu, msr_no, l, h, 0);
+ return _rdmsr_on_cpu(cpu, msr_no, l, h, 0);
}
/* These "safe" variants are slower and should be used when the target MSR
diff --git a/include/asm-x86/msr.h b/include/asm-x86/msr.h
index ca110ee..ad5f2de 100644
--- a/include/asm-x86/msr.h
+++ b/include/asm-x86/msr.h
@@ -192,19 +192,20 @@
#define write_rdtscp_aux(val) wrmsr(0xc0000103, (val), 0)
#ifdef CONFIG_SMP
-void rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h);
-void wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h);
+int rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h);
+int wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h);
int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h);
-
int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h);
#else /* CONFIG_SMP */
-static inline void rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
+static inline int rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
{
rdmsr(msr_no, *l, *h);
+ return 0;
}
-static inline void wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
+static inline int wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
{
wrmsr(msr_no, l, h);
+ return 0;
}
static inline int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no,
u32 *l, u32 *h)