Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
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>
+10
-4
arch/x86/kernel/msr.c
+10
-4
arch/x86/kernel/msr.c
···
79
79
80
80
for (; count; count -= 8) {
81
81
err = rdmsr_safe_on_cpu(cpu, reg, &data[0], &data[1]);
82
-
if (err)
83
-
return -EIO;
82
+
if (err) {
83
+
if (err == -EFAULT) /* Fix idiotic error code */
84
+
err = -EIO;
85
+
return err;
86
+
}
84
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if (copy_to_user(tmp, &data, 8))
85
88
return -EFAULT;
86
89
tmp += 2;
···
108
105
if (copy_from_user(&data, tmp, 8))
109
106
return -EFAULT;
110
107
err = wrmsr_safe_on_cpu(cpu, reg, data[0], data[1]);
111
-
if (err)
112
-
return -EIO;
108
+
if (err) {
109
+
if (err == -EFAULT) /* Fix idiotic error code */
110
+
err = -EIO;
111
+
return err;
112
+
}
113
113
tmp += 2;
114
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}
115
115
+12
-10
arch/x86/lib/msr-on-cpu.c
+12
-10
arch/x86/lib/msr-on-cpu.c
···
30
30
31
31
rv.msr_no = msr_no;
32
32
if (safe) {
33
-
smp_call_function_single(cpu, __rdmsr_safe_on_cpu, &rv, 1);
34
-
err = rv.err;
33
+
err = smp_call_function_single(cpu, __rdmsr_safe_on_cpu,
34
+
&rv, 1);
35
+
err = err ? err : rv.err;
35
36
} else {
36
-
smp_call_function_single(cpu, __rdmsr_on_cpu, &rv, 1);
37
+
err = smp_call_function_single(cpu, __rdmsr_on_cpu, &rv, 1);
37
38
}
38
39
*l = rv.l;
39
40
*h = rv.h;
···
65
64
rv.l = l;
66
65
rv.h = h;
67
66
if (safe) {
68
-
smp_call_function_single(cpu, __wrmsr_safe_on_cpu, &rv, 1);
69
-
err = rv.err;
67
+
err = smp_call_function_single(cpu, __wrmsr_safe_on_cpu,
68
+
&rv, 1);
69
+
err = err ? err : rv.err;
70
70
} else {
71
-
smp_call_function_single(cpu, __wrmsr_on_cpu, &rv, 1);
71
+
err = smp_call_function_single(cpu, __wrmsr_on_cpu, &rv, 1);
72
72
}
73
73
74
74
return err;
75
75
}
76
76
77
-
void wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
77
+
int wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
78
78
{
79
-
_wrmsr_on_cpu(cpu, msr_no, l, h, 0);
79
+
return _wrmsr_on_cpu(cpu, msr_no, l, h, 0);
80
80
}
81
81
82
-
void rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
82
+
int rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
83
83
{
84
-
_rdmsr_on_cpu(cpu, msr_no, l, h, 0);
84
+
return _rdmsr_on_cpu(cpu, msr_no, l, h, 0);
85
85
}
86
86
87
87
/* These "safe" variants are slower and should be used when the target MSR
+6
-5
include/asm-x86/msr.h
+6
-5
include/asm-x86/msr.h
···
192
192
#define write_rdtscp_aux(val) wrmsr(0xc0000103, (val), 0)
193
193
194
194
#ifdef CONFIG_SMP
195
-
void rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h);
196
-
void wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h);
195
+
int rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h);
196
+
int wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h);
197
197
int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h);
198
-
199
198
int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h);
200
199
#else /* CONFIG_SMP */
201
-
static inline void rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
200
+
static inline int rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
202
201
{
203
202
rdmsr(msr_no, *l, *h);
203
+
return 0;
204
204
}
205
-
static inline void wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
205
+
static inline int wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
206
206
{
207
207
wrmsr(msr_no, l, h);
208
+
return 0;
208
209
}
209
210
static inline int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no,
210
211
u32 *l, u32 *h)