From c6f31932d0a1d2b13952f506ebc92675e2d8df80 Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin" Date: Mon, 25 Aug 2008 17:27:21 -0700 Subject: [PATCH] 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 --- arch/x86/kernel/msr.c | 14 ++++++++++---- arch/x86/lib/msr-on-cpu.c | 22 ++++++++++++---------- include/asm-x86/msr.h | 11 ++++++----- 3 files changed, 28 insertions(+), 19 deletions(-) diff --git a/arch/x86/kernel/msr.c b/arch/x86/kernel/msr.c index e4393808688..9c34a1005db 100644 --- a/arch/x86/kernel/msr.c +++ b/arch/x86/kernel/msr.c @@ -79,8 +79,11 @@ static ssize_t msr_read(struct file *file, char __user *buf, 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 @@ static ssize_t msr_write(struct file *file, const char __user *buf, 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 d5a2b39f882..01b868ba82f 100644 --- a/arch/x86/lib/msr-on-cpu.c +++ b/arch/x86/lib/msr-on-cpu.c @@ -30,10 +30,11 @@ static int _rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h, int safe) 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 @@ static int _wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h, int safe) 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 ca110ee73f0..ad5f2decf7f 100644 --- a/include/asm-x86/msr.h +++ b/include/asm-x86/msr.h @@ -192,19 +192,20 @@ do { \ #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) -- 2.41.0