Merge branch 'for-linus' of git://one.firstfloor.org/home/andi/git/linux-2.6

* 'for-linus' of git://one.firstfloor.org/home/andi/git/linux-2.6: (94 commits)
  [PATCH] x86-64: Remove mk_pte_phys()
  [PATCH] i386: Fix broken CONFIG_COMPAT_VDSO on i386
  [PATCH] i386: fix 32-bit ioctls on x64_32
  [PATCH] x86: Unify pcspeaker platform device code between i386/x86-64
  [PATCH] i386: Remove extern declaration from mm/discontig.c, put in header.
  [PATCH] i386: Rename cpu_gdt_descr and remove extern declaration from smpboot.c
  [PATCH] i386: Move mce_disabled to asm/mce.h
  [PATCH] i386: paravirt unhandled fallthrough
  [PATCH] x86_64: Wire up compat epoll_pwait
  [PATCH] x86: Don't require the vDSO for handling a.out signals
  [PATCH] i386: Fix Cyrix MediaGX detection
  [PATCH] i386: Fix warning in cpu initialization
  [PATCH] i386: Fix warning in microcode.c
  [PATCH] x86: Enable NMI watchdog for AMD Family 0x10 CPUs
  [PATCH] x86: Add new CPUID bits for AMD Family 10 CPUs in /proc/cpuinfo
  [PATCH] i386: Remove fastcall in paravirt.[ch]
  [PATCH] x86-64: Fix wrong gcc check in bitops.h
  [PATCH] x86-64: survive having no irq mapping for a vector
  [PATCH] i386: geode configuration fixes
  [PATCH] i386: add option to show more code in oops reports
  ...

kernel/kmod.c

@@ -217,7 +217,10 @@ static int wait_for_helper(void *data)
 			sub_info->retval = ret;
 	}
 
-	complete(sub_info->complete);
+	if (sub_info->wait < 0)
+		kfree(sub_info);
+	else
+		complete(sub_info->complete);
 	return 0;
 }
 
@@ -239,6 +242,9 @@ static void __call_usermodehelper(struct work_struct *work)
 		pid = kernel_thread(____call_usermodehelper, sub_info,
 				    CLONE_VFORK | SIGCHLD);
 
+	if (wait < 0)
+		return;
+
 	if (pid < 0) {
 		sub_info->retval = pid;
 		complete(sub_info->complete);
@@ -253,6 +259,9 @@ static void __call_usermodehelper(struct work_struct *work)
  * @envp: null-terminated environment list
  * @session_keyring: session keyring for process (NULL for an empty keyring)
  * @wait: wait for the application to finish and return status.
+ *        when -1 don't wait at all, but you get no useful error back when
+ *        the program couldn't be exec'ed. This makes it safe to call
+ *        from interrupt context.
  *
  * Runs a user-space application.  The application is started
  * asynchronously if wait is not set, and runs as a child of keventd.
@@ -265,17 +274,8 @@ int call_usermodehelper_keys(char *path, char **argv, char **envp,
 			     struct key *session_keyring, int wait)
 {
 	DECLARE_COMPLETION_ONSTACK(done);
-	struct subprocess_info sub_info = {
-		.work		= __WORK_INITIALIZER(sub_info.work,
-						     __call_usermodehelper),
-		.complete	= &done,
-		.path		= path,
-		.argv		= argv,
-		.envp		= envp,
-		.ring		= session_keyring,
-		.wait		= wait,
-		.retval		= 0,
-	};
+	struct subprocess_info *sub_info;
+	int retval;
 
 	if (!khelper_wq)
 		return -EBUSY;
@@ -283,9 +283,25 @@ int call_usermodehelper_keys(char *path, char **argv, char **envp,
 	if (path[0] == '\0')
 		return 0;
 
-	queue_work(khelper_wq, &sub_info.work);
+	sub_info = kzalloc(sizeof(struct subprocess_info),  GFP_ATOMIC);
+	if (!sub_info)
+		return -ENOMEM;
+
+	INIT_WORK(&sub_info->work, __call_usermodehelper);
+	sub_info->complete = &done;
+	sub_info->path = path;
+	sub_info->argv = argv;
+	sub_info->envp = envp;
+	sub_info->ring = session_keyring;
+	sub_info->wait = wait;
+
+	queue_work(khelper_wq, &sub_info->work);
+	if (wait < 0) /* task has freed sub_info */
+		return 0;
 	wait_for_completion(&done);
-	return sub_info.retval;
+	retval = sub_info->retval;
+	kfree(sub_info);
+	return retval;
 }
 EXPORT_SYMBOL(call_usermodehelper_keys);
 

kernel/sched.c

@@ -1853,6 +1853,13 @@ context_switch(struct rq *rq, struct task_struct *prev,
 	struct mm_struct *mm = next->mm;
 	struct mm_struct *oldmm = prev->active_mm;
 
+	/*
+	 * For paravirt, this is coupled with an exit in switch_to to
+	 * combine the page table reload and the switch backend into
+	 * one hypercall.
+	 */
+	arch_enter_lazy_cpu_mode();
+
 	if (!mm) {
 		next->active_mm = oldmm;
 		atomic_inc(&oldmm->mm_count);

kernel/timer.c

@@ -1162,11 +1162,9 @@ static inline void calc_load(unsigned long ticks)
  * This read-write spinlock protects us from races in SMP while
  * playing with xtime and avenrun.
  */
-#ifndef ARCH_HAVE_XTIME_LOCK
-__cacheline_aligned_in_smp DEFINE_SEQLOCK(xtime_lock);
+__attribute__((weak)) __cacheline_aligned_in_smp DEFINE_SEQLOCK(xtime_lock);
 
 EXPORT_SYMBOL(xtime_lock);
-#endif
 
 /*
  * This function runs timers and the timer-tq in bottom half context.