bug in cpuid & msr on nosmp machine

@@ -135,7 +135,7 @@
   int cpu = iminor(file->f_dentry->d_inode);
   struct cpuinfo_x86 *c = &(cpu_data)[cpu];
 
-  if (cpu >= num_possible_cpus() || !cpu_online(cpu))
+  if (!cpu_online(cpu))
     return -ENXIO;		/* No such CPU */
   if ( c->cpuid_level < 0 )
     return -EIO;		/* CPUID not supported */

@@ -241,7 +241,7 @@
   int cpu = iminor(file->f_dentry->d_inode);
   struct cpuinfo_x86 *c = &(cpu_data)[cpu];
   
-  if (cpu >= num_possible_cpus() || !cpu_online(cpu))
+  if (!cpu_online(cpu))
     return -ENXIO;		/* No such CPU */
   if ( !cpu_has(c, X86_FEATURE_MSR) )
     return -EIO;		/* MSR not supported */

@@ -135,7 +135,7 @@
   int cpu = iminor(file->f_dentry->d_inode);
   struct cpuinfo_x86 *c = &(cpu_data)[cpu];
 
-  if (!cpu_online(cpu))
+  if (cpu >= num_possible_cpus() || !cpu_online(cpu))
     return -ENXIO;		/* No such CPU */
   if ( c->cpuid_level < 0 )
     return -EIO;		/* CPUID not supported */

@@ -241,7 +241,7 @@
   int cpu = iminor(file->f_dentry->d_inode);
   struct cpuinfo_x86 *c = &(cpu_data)[cpu];
   
-  if (!cpu_online(cpu))
+  if (cpu >= num_possible_cpus() || !cpu_online(cpu))
     return -ENXIO;		/* No such CPU */
   if ( !cpu_has(c, X86_FEATURE_MSR) )
     return -EIO;		/* MSR not supported */

diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .7878-linux-2.6.6-bk6/arch/i386/kernel/cpuid.c .7878-linux-2.6.6-bk6.updated/arch/i386/kernel/cpuid.c
@@ -132,10 +132,10 @@ static ssize_t cpuid_read(struct file *f
 
 static int cpuid_open(struct inode *inode, struct file *file)
 {
-	int cpu = iminor(file->f_dentry->d_inode);
+	unsigned int cpu = iminor(file->f_dentry->d_inode);
 	struct cpuinfo_x86 *c = &(cpu_data)[cpu];
 
-	if (!cpu_online(cpu))
+	if (cpu >= NR_CPUS || !cpu_online(cpu))
 		return -ENXIO;	/* No such CPU */
 	if (c->cpuid_level < 0)
 		return -EIO;	/* CPUID not supported */

diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .7878-linux-2.6.6-bk6/arch/i386/kernel/msr.c .7878-linux-2.6.6-bk6.updated/arch/i386/kernel/msr.c
@@ -238,10 +238,10 @@ static ssize_t msr_write(struct file * f
 
 static int msr_open(struct inode *inode, struct file *file)
 {
-  int cpu = iminor(file->f_dentry->d_inode);
+  unsigned int cpu = iminor(file->f_dentry->d_inode);
   struct cpuinfo_x86 *c = &(cpu_data)[cpu];
   
-  if (!cpu_online(cpu))
+  if (cpu >= NR_CPUS || !cpu_online(cpu))
     return -ENXIO;		/* No such CPU */
   if ( !cpu_has(c, X86_FEATURE_MSR) )
     return -EIO;		/* MSR not supported */

diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .21074-linux-2.6.5/include/linux/smp.h .21074-linux-2.6.5.updated/include/linux/smp.h
@@ -8,6 +8,10 @@
 
 #include <linux/config.h>
 
+#define get_cpu()		({ preempt_disable(); smp_processor_id(); })
+#define put_cpu()		preempt_enable()
+#define put_cpu_no_resched()	preempt_enable_no_resched()
+
 #ifdef CONFIG_SMP
 
 #include <linux/preempt.h>

@@ -69,6 +73,24 @@ static inline int on_each_cpu(void (*fun
 	return ret;
 }
 
+#ifndef __HAVE_ARCH_ON_ONE_CPU
+extern int __on_one_cpu(unsigned cpu, void (*func)(void *info), void *info);
+static inline int on_one_cpu(unsigned cpu,
+			     void (*func)(void *info), void *info)
+{
+	int ret;
+
+	if (cpu == get_cpu()) {
+		func(info);
+		ret = 0;
+	} else
+		ret = __on_one_cpu(cpu, func, info);
+	put_cpu();
+	return ret;
+}
+#endif
+
+
 /*
  * True once the per process idle is forked
  */

@@ -123,6 +123,7 @@ void smp_prepare_boot_cpu(void);
 #define smp_threads_ready			1
 #define smp_call_function(func,info,retry,wait)	({ 0; })
 #define on_each_cpu(func,info,retry,wait)	({ func(info); 0; })
+#define on_one_cpu(cpu,func,info)		({ func(info); 0; })
 static inline void smp_send_reschedule(int cpu) { }
 #define num_booting_cpus()			1
 #define smp_prepare_boot_cpu()			do {} while (0)

@@ -107,8 +129,4 @@ static inline void smp_send_reschedule(i
 
 #endif /* !SMP */
 
-#define get_cpu()		({ preempt_disable(); smp_processor_id(); })
-#define put_cpu()		preempt_enable()
-#define put_cpu_no_resched()	preempt_enable_no_resched()
-
 #endif /* __LINUX_SMP_H */

diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .21074-linux-2.6.5/kernel/sched.c .21074-linux-2.6.5.updated/kernel/sched.c
@@ -631,7 +631,29 @@ void kick_process(task_t *p)
 
 EXPORT_SYMBOL_GPL(kick_process);
 
-#endif
+#ifndef __HAVE_ARCH_ON_ONE_CPU
+struct which_cpu
+{
+	unsigned int cpu;
+	void (*func)(void *info);
+	void *info;
+};
+
+static void maybe_on_cpu(void *_which)
+{
+	struct which_cpu *which = _which;
+
+	if (smp_processor_id() == which->cpu)
+		which->func(which->info);
+}
+
+int __on_one_cpu(unsigned cpu, void (*func)(void *info), void *info)
+{
+	struct which_cpu which = { cpu, info };
+	return smp_call_function(maybe_on_cpu, &which, 1, 1);
+}
+#endif /* __HAVE_ARCH_ON_ONE_CPU */
+#endif /* CONFIG_SMP */
 
 /***
  * try_to_wake_up - wake up a thread

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@@ -133,10 +133,12 @@ static ssize_t cpuid_read(struct file *f
 static int cpuid_open(struct inode *inode, struct file *file)
 {
 	int cpu = iminor(file->f_dentry->d_inode);
-	struct cpuinfo_x86 *c = &(cpu_data)[cpu];
+	struct cpuinfo_x86 *c;
 
-	if (!cpu_online(cpu))
+	if (!cpu_possible(cpu) || !cpu_online(cpu))
 		return -ENXIO;	/* No such CPU */
+
+	c = &(cpu_data)[cpu];
 	if (c->cpuid_level < 0)
 		return -EIO;	/* CPUID not supported */
 

diff -puN arch/i386/kernel/msr.c~cpuid-msr-range-checking-fix arch/i386/kernel/msr.c
@@ -239,10 +239,12 @@ static ssize_t msr_write(struct file * f
 static int msr_open(struct inode *inode, struct file *file)
 {
   int cpu = iminor(file->f_dentry->d_inode);
-  struct cpuinfo_x86 *c = &(cpu_data)[cpu];
-  
-  if (!cpu_online(cpu))
-    return -ENXIO;		/* No such CPU */
+  struct cpuinfo_x86 *c;
+
+  if (!cpu_possible(cpu) || !cpu_online(cpu))
+    return -ENXIO;	/* No such CPU */
+
+  c = &(cpu_data)[cpu];
   if ( !cpu_has(c, X86_FEATURE_MSR) )
     return -EIO;		/* MSR not supported */
   

diff -puN arch/i386/kernel/cpuid.c~cpuid-msr-range-checking-fix arch/i386/kernel/cpuid.c
@@ -115,9 +115,19 @@ static ssize_t cpuid_read(struct file *f
 	size_t rv;
 	u32 reg = *ppos;
 	int cpu = iminor(file->f_dentry->d_inode);
+	ssize_t ret = 0;
 
-	if (count % 16)
-		return -EINVAL;	/* Invalid chunk size */
+	lock_cpu_hotplug();
+
+	if (!cpu_possible(cpu) || !cpu_online(cpu)) {
+		ret = -ENXIO;	/* No such CPU */
+		goto out;
+	}
+
+	if (count % 16) {
+		ret = -EINVAL;	/* Invalid chunk size */
+		goto out;
+	}
 
 	for (rv = 0; count; count -= 16) {
 		do_cpuid(cpu, reg, data);

@@ -127,20 +137,32 @@ static ssize_t cpuid_read(struct file *f
 		*ppos = reg++;
 	}
 
-	return ((char *)tmp) - buf;
+	ret = ((char *)tmp) - buf;
+out:
+	lock_cpu_hotplug();
+	return ret;
 }
 
 static int cpuid_open(struct inode *inode, struct file *file)
 {
 	int cpu = iminor(file->f_dentry->d_inode);
-	struct cpuinfo_x86 *c = &(cpu_data)[cpu];
+	struct cpuinfo_x86 *c;
+	int ret = 0;
 
-	if (!cpu_online(cpu))
-		return -ENXIO;	/* No such CPU */
+	lock_cpu_hotplug();
+
+	if (!cpu_possible(cpu) || !cpu_online(cpu)) {
+		ret = -ENXIO;	/* No such CPU */
+		goot out;
+	}
+
+	c = &(cpu_data)[cpu];
 	if (c->cpuid_level < 0)
-		return -EIO;	/* CPUID not supported */
+		ret = -EIO;	/* CPUID not supported */
 
-	return 0;
+out:
+	unlock_cpu_hotplug();
+	return ret;
 }
 
 /*

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