6 files changed, 135 insertions, 16 deletions

diff --git a/kernel/irq/autoprobe.c b/kernel/irq/autoprobe.c
index 98d62d8efeaf..3467097ca61a 100644
--- a/kernel/irq/autoprobe.c
+++ b/kernel/irq/autoprobe.c
@@ -9,6 +9,7 @@
 #include <linux/irq.h>
 #include <linux/module.h>
 #include <linux/interrupt.h>
+#include <linux/delay.h>
 
 /*
  * Autodetection depends on the fact that any interrupt that
@@ -26,7 +27,7 @@ static DECLARE_MUTEX(probe_sem);
  */
 unsigned long probe_irq_on(void)
 {
-        unsigned long val, delay;
+        unsigned long val;
         irq_desc_t *desc;
         unsigned int i;
 
@@ -45,8 +46,7 @@ unsigned long probe_irq_on(void)
         }
 
         /* Wait for longstanding interrupts to trigger. */
-        for (delay = jiffies + HZ/50; time_after(delay, jiffies); )
-                /* about 20ms delay */ barrier();
+        msleep(20);
 
         /*
          * enable any unassigned irqs
@@ -68,8 +68,7 @@ unsigned long probe_irq_on(void)
         /*
          * Wait for spurious interrupts to trigger
          */
-        for (delay = jiffies + HZ/10; time_after(delay, jiffies); )
-                /* about 100ms delay */ barrier();
+        msleep(100);
 
         /*
          * Now filter out any obviously spurious interrupts
diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index 436c7d93c00a..c29f83c16497 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -172,7 +172,7 @@ fastcall unsigned int __do_IRQ(unsigned int irq, struct pt_regs *regs)
 
                 spin_lock(&desc->lock);
                 if (!noirqdebug)
-                        note_interrupt(irq, desc, action_ret);
+                        note_interrupt(irq, desc, action_ret, regs);
                 if (likely(!(desc->status & IRQ_PENDING)))
                         break;
                 desc->status &= ~IRQ_PENDING;
diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c
index ba039e827d58..7df9abd5ec86 100644
--- a/kernel/irq/spurious.c
+++ b/kernel/irq/spurious.c
@@ -11,6 +11,83 @@
 #include <linux/kallsyms.h>
 #include <linux/interrupt.h>
 
+static int irqfixup;
+
+/*
+ * Recovery handler for misrouted interrupts.
+ */
+
+static int misrouted_irq(int irq, struct pt_regs *regs)
+{
+        int i;
+        irq_desc_t *desc;
+        int ok = 0;
+        int work = 0;   /* Did we do work for a real IRQ */
+
+        for(i = 1; i < NR_IRQS; i++) {
+                struct irqaction *action;
+
+                if (i == irq)   /* Already tried */
+                        continue;
+                desc = &irq_desc[i];
+                spin_lock(&desc->lock);
+                action = desc->action;
+                /* Already running on another processor */
+                if (desc->status & IRQ_INPROGRESS) {
+                        /*
+                         * Already running: If it is shared get the other
+                         * CPU to go looking for our mystery interrupt too
+                         */
+                        if (desc->action && (desc->action->flags & SA_SHIRQ))
+                                desc->status |= IRQ_PENDING;
+                        spin_unlock(&desc->lock);
+                        continue;
+                }
+                /* Honour the normal IRQ locking */
+                desc->status |= IRQ_INPROGRESS;
+                spin_unlock(&desc->lock);
+                while (action) {
+                        /* Only shared IRQ handlers are safe to call */
+                        if (action->flags & SA_SHIRQ) {
+                                if (action->handler(i, action->dev_id, regs) ==
+                                                IRQ_HANDLED)
+                                        ok = 1;
+                        }
+                        action = action->next;
+                }
+                local_irq_disable();
+                /* Now clean up the flags */
+                spin_lock(&desc->lock);
+                action = desc->action;
+
+                /*
+                 * While we were looking for a fixup someone queued a real
+                 * IRQ clashing with our walk
+                 */
+
+                while ((desc->status & IRQ_PENDING) && action) {
+                        /*
+                         * Perform real IRQ processing for the IRQ we deferred
+                         */
+                        work = 1;
+                        spin_unlock(&desc->lock);
+                        handle_IRQ_event(i, regs, action);
+                        spin_lock(&desc->lock);
+                        desc->status &= ~IRQ_PENDING;
+                }
+                desc->status &= ~IRQ_INPROGRESS;
+                /*
+                 * If we did actual work for the real IRQ line we must let the
+                 * IRQ controller clean up too
+                 */
+                if(work)
+                        desc->handler->end(i);
+                spin_unlock(&desc->lock);
+        }
+        /* So the caller can adjust the irq error counts */
+        return ok;
+}
+
 /*
  * If 99,900 of the previous 100,000 interrupts have not been handled
  * then assume that the IRQ is stuck in some manner. Drop a diagnostic
@@ -31,7 +108,8 @@ __report_bad_irq(unsigned int irq, irq_desc_t *desc, irqreturn_t action_ret)
                 printk(KERN_ERR "irq event %d: bogus return value %x\n",
                                 irq, action_ret);
         } else {
-                printk(KERN_ERR "irq %d: nobody cared!\n", irq);
+                printk(KERN_ERR "irq %d: nobody cared (try booting with "
+                                "the \"irqpoll\" option)\n", irq);
         }
         dump_stack();
         printk(KERN_ERR "handlers:\n");
@@ -55,7 +133,8 @@ static void report_bad_irq(unsigned int irq, irq_desc_t *desc, irqreturn_t actio
         }
 }
 
-void note_interrupt(unsigned int irq, irq_desc_t *desc, irqreturn_t action_ret)
+void note_interrupt(unsigned int irq, irq_desc_t *desc, irqreturn_t action_ret,
+                        struct pt_regs *regs)
 {
         if (action_ret != IRQ_HANDLED) {
                 desc->irqs_unhandled++;
@@ -63,6 +142,15 @@ void note_interrupt(unsigned int irq, irq_desc_t *desc, irqreturn_t action_ret)
                         report_bad_irq(irq, desc, action_ret);
         }
 
+        if (unlikely(irqfixup)) {
+                /* Don't punish working computers */
+                if ((irqfixup == 2 && irq == 0) || action_ret == IRQ_NONE) {
+                        int ok = misrouted_irq(irq, regs);
+                        if (action_ret == IRQ_NONE)
+                                desc->irqs_unhandled -= ok;
+                }
+        }
+
         desc->irq_count++;
         if (desc->irq_count < 100000)
                 return;
@@ -94,3 +182,24 @@ int __init noirqdebug_setup(char *str)
 
 __setup("noirqdebug", noirqdebug_setup);
 
+static int __init irqfixup_setup(char *str)
+{
+        irqfixup = 1;
+        printk(KERN_WARNING "Misrouted IRQ fixup support enabled.\n");
+        printk(KERN_WARNING "This may impact system performance.\n");
+        return 1;
+}
+
+__setup("irqfixup", irqfixup_setup);
+
+static int __init irqpoll_setup(char *str)
+{
+        irqfixup = 2;
+        printk(KERN_WARNING "Misrouted IRQ fixup and polling support "
+                                "enabled\n");
+        printk(KERN_WARNING "This may significantly impact system "
+                                "performance\n");
+        return 1;
+}
+
+__setup("irqpoll", irqpoll_setup);
diff --git a/kernel/itimer.c b/kernel/itimer.c
index 1dc988e0d2c7..a72cb0e5aa4b 100644
--- a/kernel/itimer.c
+++ b/kernel/itimer.c
@@ -153,11 +153,15 @@ int do_setitimer(int which, struct itimerval *value, struct itimerval *ovalue)
 
         switch (which) {
         case ITIMER_REAL:
+again:
                 spin_lock_irq(&tsk->sighand->siglock);
                 interval = tsk->signal->it_real_incr;
                 val = it_real_value(tsk->signal);
-                if (val)
-                        del_timer_sync(&tsk->signal->real_timer);
+                /* We are sharing ->siglock with it_real_fn() */
+                if (try_to_del_timer_sync(&tsk->signal->real_timer) < 0) {
+                        spin_unlock_irq(&tsk->sighand->siglock);
+                        goto again;
+                }
                 tsk->signal->it_real_incr =
                         timeval_to_jiffies(&value->it_interval);
                 it_real_arm(tsk, timeval_to_jiffies(&value->it_value));
diff --git a/kernel/kexec.c b/kernel/kexec.c
index 7843548cf2d9..cdd4dcd8fb63 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -241,7 +241,7 @@ static int kimage_normal_alloc(struct kimage **rimage, unsigned long entry,
 
 static int kimage_crash_alloc(struct kimage **rimage, unsigned long entry,
                                 unsigned long nr_segments,
-                                struct kexec_segment *segments)
+                                struct kexec_segment __user *segments)
 {
         int result;
         struct kimage *image;
@@ -650,7 +650,7 @@ static kimage_entry_t *kimage_dst_used(struct kimage *image,
                 }
         }
 
-        return 0;
+        return NULL;
 }
 
 static struct page *kimage_alloc_page(struct kimage *image,
@@ -696,7 +696,7 @@ static struct page *kimage_alloc_page(struct kimage *image,
                 /* Allocate a page, if we run out of memory give up */
                 page = kimage_alloc_pages(gfp_mask, 0);
                 if (!page)
-                        return 0;
+                        return NULL;
                 /* If the page cannot be used file it away */
                 if (page_to_pfn(page) >
                                 (KEXEC_SOURCE_MEMORY_LIMIT >> PAGE_SHIFT)) {
@@ -754,7 +754,7 @@ static int kimage_load_normal_segment(struct kimage *image,
         unsigned long maddr;
         unsigned long ubytes, mbytes;
         int result;
-        unsigned char *buf;
+        unsigned char __user *buf;
 
         result = 0;
         buf = segment->buf;
@@ -818,7 +818,7 @@ static int kimage_load_crash_segment(struct kimage *image,
         unsigned long maddr;
         unsigned long ubytes, mbytes;
         int result;
-        unsigned char *buf;
+        unsigned char __user *buf;
 
         result = 0;
         buf = segment->buf;
diff --git a/kernel/sched.c b/kernel/sched.c
index e2b0d3e4dd06..5f2182d42241 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -4166,6 +4166,14 @@ void show_state(void)
         read_unlock(&tasklist_lock);
 }
 
+/**
+ * init_idle - set up an idle thread for a given CPU
+ * @idle: task in question
+ * @cpu: cpu the idle task belongs to
+ *
+ * NOTE: this function does not set the idle thread's NEED_RESCHED
+ * flag, to make booting more robust.
+ */
 void __devinit init_idle(task_t *idle, int cpu)
 {
         runqueue_t *rq = cpu_rq(cpu);
@@ -4183,7 +4191,6 @@ void __devinit init_idle(task_t *idle, int cpu)
 #if defined(CONFIG_SMP) && defined(__ARCH_WANT_UNLOCKED_CTXSW)
         idle->oncpu = 1;
 #endif
-        set_tsk_need_resched(idle);
         spin_unlock_irqrestore(&rq->lock, flags);
 
         /* Set the preempt count _outside_ the spinlocks! */