Merge branch 'x86-fixes-for-linus' of...

Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: update defconfigs
  x86: msr: fix bogus return values from rdmsr_safe/wrmsr_safe
  x86: cpuid: correct return value on partial operations
  x86: msr: correct return value on partial operations
  x86: cpuid: propagate error from smp_call_function_single()
  x86: msr: propagate errors from smp_call_function_single()
  smp: have smp_call_function_single() detect invalid CPUs

arch/x86/kernel/cpuid.c

@@ -89,6 +89,8 @@ static ssize_t cpuid_read(struct file *file, char __user *buf,
 	struct cpuid_regs cmd;
 	int cpu = iminor(file->f_path.dentry->d_inode);
 	u64 pos = *ppos;
+	ssize_t bytes = 0;
+	int err = 0;
 
 	if (count % 16)
 		return -EINVAL;	/* Invalid chunk size */
@@ -96,14 +98,19 @@ static ssize_t cpuid_read(struct file *file, char __user *buf,
 	for (; count; count -= 16) {
 		cmd.eax = pos;
 		cmd.ecx = pos >> 32;
-		smp_call_function_single(cpu, cpuid_smp_cpuid, &cmd, 1);
-		if (copy_to_user(tmp, &cmd, 16))
-			return -EFAULT;
+		err = smp_call_function_single(cpu, cpuid_smp_cpuid, &cmd, 1);
+		if (err)
+			break;
+		if (copy_to_user(tmp, &cmd, 16)) {
+			err = -EFAULT;
+			break;
+		}
 		tmp += 16;
+		bytes += 16;
 		*ppos = ++pos;
 	}
 
-	return tmp - buf;
+	return bytes ? bytes : err;
 }
 
 static int cpuid_open(struct inode *inode, struct file *file)

arch/x86/kernel/msr.c

@@ -72,21 +72,28 @@ static ssize_t msr_read(struct file *file, char __user *buf,
 	u32 data[2];
 	u32 reg = *ppos;
 	int cpu = iminor(file->f_path.dentry->d_inode);
-	int err;
+	int err = 0;
+	ssize_t bytes = 0;
 
 	if (count % 8)
 		return -EINVAL;	/* Invalid chunk size */
 
 	for (; count; count -= 8) {
 		err = rdmsr_safe_on_cpu(cpu, reg, &data[0], &data[1]);
-		if (err)
-			return -EIO;
-		if (copy_to_user(tmp, &data, 8))
-			return -EFAULT;
+		if (err) {
+			if (err == -EFAULT) /* Fix idiotic error code */
+				err = -EIO;
+			break;
+		}
+		if (copy_to_user(tmp, &data, 8)) {
+			err = -EFAULT;
+			break;
+		}
 		tmp += 2;
+		bytes += 8;
 	}
 
-	return ((char __user *)tmp) - buf;
+	return bytes ? bytes : err;
 }
 
 static ssize_t msr_write(struct file *file, const char __user *buf,
@@ -96,21 +103,28 @@ static ssize_t msr_write(struct file *file, const char __user *buf,
 	u32 data[2];
 	u32 reg = *ppos;
 	int cpu = iminor(file->f_path.dentry->d_inode);
-	int err;
+	int err = 0;
+	ssize_t bytes = 0;
 
 	if (count % 8)
 		return -EINVAL;	/* Invalid chunk size */
 
 	for (; count; count -= 8) {
-		if (copy_from_user(&data, tmp, 8))
-			return -EFAULT;
+		if (copy_from_user(&data, tmp, 8)) {
+			err = -EFAULT;
+			break;
+		}
 		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;
+			break;
+		}
 		tmp += 2;
+		bytes += 8;
 	}
 
-	return ((char __user *)tmp) - buf;
+	return bytes ? bytes : err;
 }
 
 static int msr_open(struct inode *inode, struct file *file)

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

include/asm-x86/msr.h

@@ -52,14 +52,14 @@ static inline unsigned long long native_read_msr_safe(unsigned int msr,
 {
 	DECLARE_ARGS(val, low, high);
 
-	asm volatile("2: rdmsr ; xor %0,%0\n"
+	asm volatile("2: rdmsr ; xor %[err],%[err]\n"
 		     "1:\n\t"
 		     ".section .fixup,\"ax\"\n\t"
-		     "3:  mov %3,%0 ; jmp 1b\n\t"
+		     "3:  mov %[fault],%[err] ; jmp 1b\n\t"
 		     ".previous\n\t"
 		     _ASM_EXTABLE(2b, 3b)
-		     : "=r" (*err), EAX_EDX_RET(val, low, high)
-		     : "c" (msr), "i" (-EFAULT));
+		     : [err] "=r" (*err), EAX_EDX_RET(val, low, high)
+		     : "c" (msr), [fault] "i" (-EFAULT));
 	return EAX_EDX_VAL(val, low, high);
 }
 
@@ -73,15 +73,15 @@ static inline int native_write_msr_safe(unsigned int msr,
 					unsigned low, unsigned high)
 {
 	int err;
-	asm volatile("2: wrmsr ; xor %0,%0\n"
+	asm volatile("2: wrmsr ; xor %[err],%[err]\n"
 		     "1:\n\t"
 		     ".section .fixup,\"ax\"\n\t"
-		     "3:  mov %4,%0 ; jmp 1b\n\t"
+		     "3:  mov %[fault],%[err] ; jmp 1b\n\t"
 		     ".previous\n\t"
 		     _ASM_EXTABLE(2b, 3b)
-		     : "=a" (err)
+		     : [err] "=a" (err)
 		     : "c" (msr), "0" (low), "d" (high),
-		       "i" (-EFAULT)
+		       [fault] "i" (-EFAULT)
 		     : "memory");
 	return err;
 }
@@ -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)

kernel/smp.c

@@ -210,8 +210,10 @@ int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
 {
 	struct call_single_data d;
 	unsigned long flags;
-	/* prevent preemption and reschedule on another processor */
+	/* prevent preemption and reschedule on another processor,
+	   as well as CPU removal */
 	int me = get_cpu();
+	int err = 0;
 
 	/* Can deadlock when called with interrupts disabled */
 	WARN_ON(irqs_disabled());
@@ -220,7 +222,7 @@ int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
 		local_irq_save(flags);
 		func(info);
 		local_irq_restore(flags);
-	} else {
+	} else if ((unsigned)cpu < NR_CPUS && cpu_online(cpu)) {
 		struct call_single_data *data = NULL;
 
 		if (!wait) {
@@ -236,10 +238,12 @@ int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
 		data->func = func;
 		data->info = info;
 		generic_exec_single(cpu, data);
+	} else {
+		err = -ENXIO;	/* CPU not online */
 	}
 
 	put_cpu();
-	return 0;
+	return err;
 }
 EXPORT_SYMBOL(smp_call_function_single);