4 files changed, 71 insertions, 170 deletions

diff --git a/arch/arm/kernel/atags.c b/arch/arm/kernel/atags.c
index 64c420805e6..42a1a1415fa 100644
--- a/arch/arm/kernel/atags.c
+++ b/arch/arm/kernel/atags.c
@@ -1,5 +1,4 @@
 #include <linux/slab.h>
-#include <linux/kexec.h>
 #include <linux/proc_fs.h>
 #include <asm/setup.h>
 #include <asm/types.h>
@@ -7,9 +6,8 @@
 
 struct buffer {
 	size_t size;
-	char *data;
+	char data[];
 };
-static struct buffer tags_buffer;
 
 static int
 read_buffer(char* page, char** start, off_t off, int count,
@@ -29,58 +27,57 @@ read_buffer(char* page, char** start, off_t off, int count,
 	return count;
 }
 
-
-static int
-create_proc_entries(void)
-{
-	struct proc_dir_entry* tags_entry;
-
-	tags_entry = create_proc_read_entry("atags", 0400, NULL, read_buffer, &tags_buffer);
-	if (!tags_entry)
-		return -ENOMEM;
-
-	return 0;
-}
-
-
-static char __initdata atags_copy_buf[KEXEC_BOOT_PARAMS_SIZE];
-static char __initdata *atags_copy;
+#define BOOT_PARAMS_SIZE 1536
+static char __initdata atags_copy[BOOT_PARAMS_SIZE];
 
 void __init save_atags(const struct tag *tags)
 {
-	atags_copy = atags_copy_buf;
-	memcpy(atags_copy, tags, KEXEC_BOOT_PARAMS_SIZE);
+	memcpy(atags_copy, tags, sizeof(atags_copy));
 }
 
-
 static int __init init_atags_procfs(void)
 {
-	struct tag *tag;
-	int error;
+	/*
+	 * This cannot go into save_atags() because kmalloc and proc don't work
+	 * yet when it is called.
+	 */
+	struct proc_dir_entry *tags_entry;
+	struct tag *tag = (struct tag *)atags_copy;
+	struct buffer *b;
+	size_t size;
 
-	if (!atags_copy) {
-		printk(KERN_WARNING "Exporting ATAGs: No saved tags found\n");
-		return -EIO;
+	if (tag->hdr.tag != ATAG_CORE) {
+		printk(KERN_INFO "No ATAGs?");
+		return -EINVAL;
 	}
 
-	for (tag = (struct tag *) atags_copy; tag->hdr.size; tag = tag_next(tag))
+	for (; tag->hdr.size; tag = tag_next(tag))
 		;
 
-	tags_buffer.size = ((char *) tag - atags_copy) + sizeof(tag->hdr);
-	tags_buffer.data = kmalloc(tags_buffer.size, GFP_KERNEL);
-	if (tags_buffer.data == NULL)
-		return -ENOMEM;
-	memcpy(tags_buffer.data, atags_copy, tags_buffer.size);
-
-	error = create_proc_entries();
-	if (error) {
-		printk(KERN_ERR "Exporting ATAGs: not enough memory\n");
-		kfree(tags_buffer.data);
-		tags_buffer.size = 0;
-		tags_buffer.data = NULL;
-	}
+	/* include the terminating ATAG_NONE */
+	size = (char *)tag - atags_copy + sizeof(struct tag_header);
 
-	return error;
-}
+	WARN_ON(tag->hdr.tag != ATAG_NONE);
+
+	b = kmalloc(sizeof(*b) + size, GFP_KERNEL);
+	if (!b)
+		goto nomem;
 
+	b->size = size;
+	memcpy(b->data, atags_copy, size);
+
+	tags_entry = create_proc_read_entry("atags", 0400,
+			NULL, read_buffer, b);
+
+	if (!tags_entry)
+		goto nomem;
+
+	return 0;
+
+nomem:
+	kfree(b);
+	printk(KERN_ERR "Exporting ATAGs: not enough memory\n");
+
+	return -ENOMEM;
+}
 arch_initcall(init_atags_procfs);
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index 46bf2ede612..199b3680118 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -133,10 +133,8 @@ static void default_idle(void)
 		cpu_relax();
 	else {
 		local_irq_disable();
-		if (!need_resched()) {
-			timer_dyn_reprogram();
+		if (!need_resched())
 			arch_idle();
-		}
 		local_irq_enable();
 	}
 }
diff --git a/arch/arm/kernel/stacktrace.c b/arch/arm/kernel/stacktrace.c
index ae31deb2d06..90e0c35ae60 100644
--- a/arch/arm/kernel/stacktrace.c
+++ b/arch/arm/kernel/stacktrace.c
@@ -36,6 +36,7 @@ EXPORT_SYMBOL(walk_stackframe);
 #ifdef CONFIG_STACKTRACE
 struct stack_trace_data {
 	struct stack_trace *trace;
+	unsigned int no_sched_functions;
 	unsigned int skip;
 };
 
@@ -43,27 +44,52 @@ static int save_trace(struct stackframe *frame, void *d)
 {
 	struct stack_trace_data *data = d;
 	struct stack_trace *trace = data->trace;
+	unsigned long addr = frame->lr;
 
+	if (data->no_sched_functions && in_sched_functions(addr))
+		return 0;
 	if (data->skip) {
 		data->skip--;
 		return 0;
 	}
 
-	trace->entries[trace->nr_entries++] = frame->lr;
+	trace->entries[trace->nr_entries++] = addr;
 
 	return trace->nr_entries >= trace->max_entries;
 }
 
-void save_stack_trace(struct stack_trace *trace)
+void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
 {
 	struct stack_trace_data data;
 	unsigned long fp, base;
 
 	data.trace = trace;
 	data.skip = trace->skip;
-	base = (unsigned long)task_stack_page(current);
-	asm("mov %0, fp" : "=r" (fp));
+	base = (unsigned long)task_stack_page(tsk);
+
+	if (tsk != current) {
+#ifdef CONFIG_SMP
+		/*
+		 * What guarantees do we have here that 'tsk'
+		 * is not running on another CPU?
+		 */
+		BUG();
+#else
+		data.no_sched_functions = 1;
+		fp = thread_saved_fp(tsk);
+#endif
+	} else {
+		data.no_sched_functions = 0;
+		asm("mov %0, fp" : "=r" (fp));
+	}
 
 	walk_stackframe(fp, base, base + THREAD_SIZE, save_trace, &data);
+	if (trace->nr_entries < trace->max_entries)
+		trace->entries[trace->nr_entries++] = ULONG_MAX;
+}
+
+void save_stack_trace(struct stack_trace *trace)
+{
+	save_stack_trace_tsk(current, trace);
 }
 #endif
diff --git a/arch/arm/kernel/time.c b/arch/arm/kernel/time.c
index b5867eca1d0..cc5145b28e7 100644
--- a/arch/arm/kernel/time.c
+++ b/arch/arm/kernel/time.c
@@ -365,108 +365,6 @@ static struct sysdev_class timer_sysclass = {
 	.resume		= timer_resume,
 };
 
-#ifdef CONFIG_NO_IDLE_HZ
-static int timer_dyn_tick_enable(void)
-{
-	struct dyn_tick_timer *dyn_tick = system_timer->dyn_tick;
-	unsigned long flags;
-	int ret = -ENODEV;
-
-	if (dyn_tick) {
-		spin_lock_irqsave(&dyn_tick->lock, flags);
-		ret = 0;
-		if (!(dyn_tick->state & DYN_TICK_ENABLED)) {
-			ret = dyn_tick->enable();
-
-			if (ret == 0)
-				dyn_tick->state |= DYN_TICK_ENABLED;
-		}
-		spin_unlock_irqrestore(&dyn_tick->lock, flags);
-	}
-
-	return ret;
-}
-
-static int timer_dyn_tick_disable(void)
-{
-	struct dyn_tick_timer *dyn_tick = system_timer->dyn_tick;
-	unsigned long flags;
-	int ret = -ENODEV;
-
-	if (dyn_tick) {
-		spin_lock_irqsave(&dyn_tick->lock, flags);
-		ret = 0;
-		if (dyn_tick->state & DYN_TICK_ENABLED) {
-			ret = dyn_tick->disable();
-
-			if (ret == 0)
-				dyn_tick->state &= ~DYN_TICK_ENABLED;
-		}
-		spin_unlock_irqrestore(&dyn_tick->lock, flags);
-	}
-
-	return ret;
-}
-
-/*
- * Reprogram the system timer for at least the calculated time interval.
- * This function should be called from the idle thread with IRQs disabled,
- * immediately before sleeping.
- */
-void timer_dyn_reprogram(void)
-{
-	struct dyn_tick_timer *dyn_tick = system_timer->dyn_tick;
-	unsigned long next, seq, flags;
-
-	if (!dyn_tick)
-		return;
-
-	spin_lock_irqsave(&dyn_tick->lock, flags);
-	if (dyn_tick->state & DYN_TICK_ENABLED) {
-		next = next_timer_interrupt();
-		do {
-			seq = read_seqbegin(&xtime_lock);
-			dyn_tick->reprogram(next - jiffies);
-		} while (read_seqretry(&xtime_lock, seq));
-	}
-	spin_unlock_irqrestore(&dyn_tick->lock, flags);
-}
-
-static ssize_t timer_show_dyn_tick(struct sys_device *dev, char *buf)
-{
-	return sprintf(buf, "%i\n",
-		       (system_timer->dyn_tick->state & DYN_TICK_ENABLED) >> 1);
-}
-
-static ssize_t timer_set_dyn_tick(struct sys_device *dev, const char *buf,
-				  size_t count)
-{
-	unsigned int enable = simple_strtoul(buf, NULL, 2);
-
-	if (enable)
-		timer_dyn_tick_enable();
-	else
-		timer_dyn_tick_disable();
-
-	return count;
-}
-static SYSDEV_ATTR(dyn_tick, 0644, timer_show_dyn_tick, timer_set_dyn_tick);
-
-/*
- * dyntick=enable|disable
- */
-static char dyntick_str[4] __initdata = "";
-
-static int __init dyntick_setup(char *str)
-{
-	if (str)
-		strlcpy(dyntick_str, str, sizeof(dyntick_str));
-	return 1;
-}
-
-__setup("dyntick=", dyntick_setup);
-#endif
-
 static int __init timer_init_sysfs(void)
 {
 	int ret = sysdev_class_register(&timer_sysclass);
@@ -475,19 +373,6 @@ static int __init timer_init_sysfs(void)
 		ret = sysdev_register(&system_timer->dev);
 	}
 
-#ifdef CONFIG_NO_IDLE_HZ
-	if (ret == 0 && system_timer->dyn_tick) {
-		ret = sysdev_create_file(&system_timer->dev, &attr_dyn_tick);
-
-		/*
-		 * Turn on dynamic tick after calibrate delay
-		 * for correct bogomips
-		 */
-		if (ret == 0 && dyntick_str[0] == 'e')
-			ret = timer_dyn_tick_enable();
-	}
-#endif
-
 	return ret;
 }
 
@@ -500,10 +385,5 @@ void __init time_init(void)
 		system_timer->offset = dummy_gettimeoffset;
 #endif
 	system_timer->init();
-
-#ifdef CONFIG_NO_IDLE_HZ
-	if (system_timer->dyn_tick)
-		spin_lock_init(&system_timer->dyn_tick->lock);
-#endif
 }