Merge branches 'tracing/ftrace' and 'tracing/function-graph-tracer' into tracing/core

arch/x86/kernel/Makefile

@@ -31,7 +31,7 @@ CFLAGS_tsc.o		:= $(nostackp)
 
 obj-y			:= process_$(BITS).o signal_$(BITS).o entry_$(BITS).o
 obj-y			+= traps.o irq.o irq_$(BITS).o dumpstack_$(BITS).o
-obj-y			+= time_$(BITS).o ioport.o ldt.o
+obj-y			+= time_$(BITS).o ioport.o ldt.o dumpstack.o
 obj-y			+= setup.o i8259.o irqinit_$(BITS).o setup_percpu.o
 obj-$(CONFIG_X86_VISWS)	+= visws_quirks.o
 obj-$(CONFIG_X86_32)	+= probe_roms_32.o

arch/x86/kernel/dumpstack.c

@@ -0,0 +1,351 @@
+/*
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *  Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
+ */
+#include <linux/kallsyms.h>
+#include <linux/kprobes.h>
+#include <linux/uaccess.h>
+#include <linux/utsname.h>
+#include <linux/hardirq.h>
+#include <linux/kdebug.h>
+#include <linux/module.h>
+#include <linux/ptrace.h>
+#include <linux/kexec.h>
+#include <linux/bug.h>
+#include <linux/nmi.h>
+#include <linux/sysfs.h>
+
+#include <asm/stacktrace.h>
+
+#include "dumpstack.h"
+
+int panic_on_unrecovered_nmi;
+unsigned int code_bytes = 64;
+int kstack_depth_to_print = 3 * STACKSLOTS_PER_LINE;
+static int die_counter;
+
+void printk_address(unsigned long address, int reliable)
+{
+	printk(" [<%p>] %s%pS\n", (void *) address,
+			reliable ? "" : "? ", (void *) address);
+}
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+static void
+print_ftrace_graph_addr(unsigned long addr, void *data,
+			const struct stacktrace_ops *ops,
+			struct thread_info *tinfo, int *graph)
+{
+	struct task_struct *task = tinfo->task;
+	unsigned long ret_addr;
+	int index = task->curr_ret_stack;
+
+	if (addr != (unsigned long)return_to_handler)
+		return;
+
+	if (!task->ret_stack || index < *graph)
+		return;
+
+	index -= *graph;
+	ret_addr = task->ret_stack[index].ret;
+
+	ops->address(data, ret_addr, 1);
+
+	(*graph)++;
+}
+#else
+static inline void
+print_ftrace_graph_addr(unsigned long addr, void *data,
+			const struct stacktrace_ops *ops,
+			struct thread_info *tinfo, int *graph)
+{ }
+#endif
+
+/*
+ * x86-64 can have up to three kernel stacks:
+ * process stack
+ * interrupt stack
+ * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
+ */
+
+static inline int valid_stack_ptr(struct thread_info *tinfo,
+			void *p, unsigned int size, void *end)
+{
+	void *t = tinfo;
+	if (end) {
+		if (p < end && p >= (end-THREAD_SIZE))
+			return 1;
+		else
+			return 0;
+	}
+	return p > t && p < t + THREAD_SIZE - size;
+}
+
+unsigned long
+print_context_stack(struct thread_info *tinfo,
+		unsigned long *stack, unsigned long bp,
+		const struct stacktrace_ops *ops, void *data,
+		unsigned long *end, int *graph)
+{
+	struct stack_frame *frame = (struct stack_frame *)bp;
+
+	while (valid_stack_ptr(tinfo, stack, sizeof(*stack), end)) {
+		unsigned long addr;
+
+		addr = *stack;
+		if (__kernel_text_address(addr)) {
+			if ((unsigned long) stack == bp + sizeof(long)) {
+				ops->address(data, addr, 1);
+				frame = frame->next_frame;
+				bp = (unsigned long) frame;
+			} else {
+				ops->address(data, addr, bp == 0);
+			}
+			print_ftrace_graph_addr(addr, data, ops, tinfo, graph);
+		}
+		stack++;
+	}
+	return bp;
+}
+
+
+static void
+print_trace_warning_symbol(void *data, char *msg, unsigned long symbol)
+{
+	printk(data);
+	print_symbol(msg, symbol);
+	printk("\n");
+}
+
+static void print_trace_warning(void *data, char *msg)
+{
+	printk("%s%s\n", (char *)data, msg);
+}
+
+static int print_trace_stack(void *data, char *name)
+{
+	printk("%s <%s> ", (char *)data, name);
+	return 0;
+}
+
+/*
+ * Print one address/symbol entries per line.
+ */
+static void print_trace_address(void *data, unsigned long addr, int reliable)
+{
+	touch_nmi_watchdog();
+	printk(data);
+	printk_address(addr, reliable);
+}
+
+static const struct stacktrace_ops print_trace_ops = {
+	.warning = print_trace_warning,
+	.warning_symbol = print_trace_warning_symbol,
+	.stack = print_trace_stack,
+	.address = print_trace_address,
+};
+
+void
+show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
+		unsigned long *stack, unsigned long bp, char *log_lvl)
+{
+	printk("%sCall Trace:\n", log_lvl);
+	dump_trace(task, regs, stack, bp, &print_trace_ops, log_lvl);
+}
+
+void show_trace(struct task_struct *task, struct pt_regs *regs,
+		unsigned long *stack, unsigned long bp)
+{
+	show_trace_log_lvl(task, regs, stack, bp, "");
+}
+
+void show_stack(struct task_struct *task, unsigned long *sp)
+{
+	show_stack_log_lvl(task, NULL, sp, 0, "");
+}
+
+/*
+ * The architecture-independent dump_stack generator
+ */
+void dump_stack(void)
+{
+	unsigned long bp = 0;
+	unsigned long stack;
+
+#ifdef CONFIG_FRAME_POINTER
+	if (!bp)
+		get_bp(bp);
+#endif
+
+	printk("Pid: %d, comm: %.20s %s %s %.*s\n",
+		current->pid, current->comm, print_tainted(),
+		init_utsname()->release,
+		(int)strcspn(init_utsname()->version, " "),
+		init_utsname()->version);
+	show_trace(NULL, NULL, &stack, bp);
+}
+EXPORT_SYMBOL(dump_stack);
+
+static raw_spinlock_t die_lock = __RAW_SPIN_LOCK_UNLOCKED;
+static int die_owner = -1;
+static unsigned int die_nest_count;
+
+unsigned __kprobes long oops_begin(void)
+{
+	int cpu;
+	unsigned long flags;
+
+	oops_enter();
+
+	/* racy, but better than risking deadlock. */
+	raw_local_irq_save(flags);
+	cpu = smp_processor_id();
+	if (!__raw_spin_trylock(&die_lock)) {
+		if (cpu == die_owner)
+			/* nested oops. should stop eventually */;
+		else
+			__raw_spin_lock(&die_lock);
+	}
+	die_nest_count++;
+	die_owner = cpu;
+	console_verbose();
+	bust_spinlocks(1);
+	return flags;
+}
+
+void __kprobes oops_end(unsigned long flags, struct pt_regs *regs, int signr)
+{
+	if (regs && kexec_should_crash(current))
+		crash_kexec(regs);
+
+	bust_spinlocks(0);
+	die_owner = -1;
+	add_taint(TAINT_DIE);
+	die_nest_count--;
+	if (!die_nest_count)
+		/* Nest count reaches zero, release the lock. */
+		__raw_spin_unlock(&die_lock);
+	raw_local_irq_restore(flags);
+	oops_exit();
+
+	if (!signr)
+		return;
+	if (in_interrupt())
+		panic("Fatal exception in interrupt");
+	if (panic_on_oops)
+		panic("Fatal exception");
+	do_exit(signr);
+}
+
+int __kprobes __die(const char *str, struct pt_regs *regs, long err)
+{
+#ifdef CONFIG_X86_32
+	unsigned short ss;
+	unsigned long sp;
+#endif
+	printk(KERN_EMERG "%s: %04lx [#%d] ", str, err & 0xffff, ++die_counter);
+#ifdef CONFIG_PREEMPT
+	printk("PREEMPT ");
+#endif
+#ifdef CONFIG_SMP
+	printk("SMP ");
+#endif
+#ifdef CONFIG_DEBUG_PAGEALLOC
+	printk("DEBUG_PAGEALLOC");
+#endif
+	printk("\n");
+	sysfs_printk_last_file();
+	if (notify_die(DIE_OOPS, str, regs, err,
+			current->thread.trap_no, SIGSEGV) == NOTIFY_STOP)
+		return 1;
+
+	show_registers(regs);
+#ifdef CONFIG_X86_32
+	sp = (unsigned long) (&regs->sp);
+	savesegment(ss, ss);
+	if (user_mode(regs)) {
+		sp = regs->sp;
+		ss = regs->ss & 0xffff;
+	}
+	printk(KERN_EMERG "EIP: [<%08lx>] ", regs->ip);
+	print_symbol("%s", regs->ip);
+	printk(" SS:ESP %04x:%08lx\n", ss, sp);
+#else
+	/* Executive summary in case the oops scrolled away */
+	printk(KERN_ALERT "RIP ");
+	printk_address(regs->ip, 1);
+	printk(" RSP <%016lx>\n", regs->sp);
+#endif
+	return 0;
+}
+
+/*
+ * This is gone through when something in the kernel has done something bad
+ * and is about to be terminated:
+ */
+void die(const char *str, struct pt_regs *regs, long err)
+{
+	unsigned long flags = oops_begin();
+	int sig = SIGSEGV;
+
+	if (!user_mode_vm(regs))
+		report_bug(regs->ip, regs);
+
+	if (__die(str, regs, err))
+		sig = 0;
+	oops_end(flags, regs, sig);
+}
+
+void notrace __kprobes
+die_nmi(char *str, struct pt_regs *regs, int do_panic)
+{
+	unsigned long flags;
+
+	if (notify_die(DIE_NMIWATCHDOG, str, regs, 0, 2, SIGINT) == NOTIFY_STOP)
+		return;
+
+	/*
+	 * We are in trouble anyway, lets at least try
+	 * to get a message out.
+	 */
+	flags = oops_begin();
+	printk(KERN_EMERG "%s", str);
+	printk(" on CPU%d, ip %08lx, registers:\n",
+		smp_processor_id(), regs->ip);
+	show_registers(regs);
+	oops_end(flags, regs, 0);
+	if (do_panic || panic_on_oops)
+		panic("Non maskable interrupt");
+	nmi_exit();
+	local_irq_enable();
+	do_exit(SIGBUS);
+}
+
+static int __init oops_setup(char *s)
+{
+	if (!s)
+		return -EINVAL;
+	if (!strcmp(s, "panic"))
+		panic_on_oops = 1;
+	return 0;
+}
+early_param("oops", oops_setup);
+
+static int __init kstack_setup(char *s)
+{
+	if (!s)
+		return -EINVAL;
+	kstack_depth_to_print = simple_strtoul(s, NULL, 0);
+	return 0;
+}
+early_param("kstack", kstack_setup);
+
+static int __init code_bytes_setup(char *s)
+{
+	code_bytes = simple_strtoul(s, NULL, 0);
+	if (code_bytes > 8192)
+		code_bytes = 8192;
+
+	return 1;
+}
+__setup("code_bytes=", code_bytes_setup);

arch/x86/kernel/dumpstack.h

@@ -0,0 +1,39 @@
+/*
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *  Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
+ */
+
+#ifndef DUMPSTACK_H
+#define DUMPSTACK_H
+
+#ifdef CONFIG_X86_32
+#define STACKSLOTS_PER_LINE 8
+#define get_bp(bp) asm("movl %%ebp, %0" : "=r" (bp) :)
+#else
+#define STACKSLOTS_PER_LINE 4
+#define get_bp(bp) asm("movq %%rbp, %0" : "=r" (bp) :)
+#endif
+
+extern unsigned long
+print_context_stack(struct thread_info *tinfo,
+		unsigned long *stack, unsigned long bp,
+		const struct stacktrace_ops *ops, void *data,
+		unsigned long *end, int *graph);
+
+extern void
+show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
+		unsigned long *stack, unsigned long bp, char *log_lvl);
+
+extern void
+show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
+		unsigned long *sp, unsigned long bp, char *log_lvl);
+
+extern unsigned int code_bytes;
+extern int kstack_depth_to_print;
+
+/* The form of the top of the frame on the stack */
+struct stack_frame {
+	struct stack_frame *next_frame;
+	unsigned long return_address;
+};
+#endif

arch/x86/kernel/dumpstack_32.c

@@ -17,69 +17,14 @@
 
 #include <asm/stacktrace.h>
 
-#define STACKSLOTS_PER_LINE 8
-#define get_bp(bp) asm("movl %%ebp, %0" : "=r" (bp) :)
-
-int panic_on_unrecovered_nmi;
-int kstack_depth_to_print = 3 * STACKSLOTS_PER_LINE;
-static unsigned int code_bytes = 64;
-static int die_counter;
-
-void printk_address(unsigned long address, int reliable)
-{
-	printk(" [<%p>] %s%pS\n", (void *) address,
-			reliable ? "" : "? ", (void *) address);
-}
-
-static inline int valid_stack_ptr(struct thread_info *tinfo,
-			void *p, unsigned int size, void *end)
-{
-	void *t = tinfo;
-	if (end) {
-		if (p < end && p >= (end-THREAD_SIZE))
-			return 1;
-		else
-			return 0;
-	}
-	return p > t && p < t + THREAD_SIZE - size;
-}
-
-/* The form of the top of the frame on the stack */
-struct stack_frame {
-	struct stack_frame *next_frame;
-	unsigned long return_address;
-};
-
-static inline unsigned long
-print_context_stack(struct thread_info *tinfo,
-		unsigned long *stack, unsigned long bp,
-		const struct stacktrace_ops *ops, void *data,
-		unsigned long *end)
-{
-	struct stack_frame *frame = (struct stack_frame *)bp;
-
-	while (valid_stack_ptr(tinfo, stack, sizeof(*stack), end)) {
-		unsigned long addr;
-
-		addr = *stack;
-		if (__kernel_text_address(addr)) {
-			if ((unsigned long) stack == bp + sizeof(long)) {
-				ops->address(data, addr, 1);
-				frame = frame->next_frame;
-				bp = (unsigned long) frame;
-			} else {
-				ops->address(data, addr, bp == 0);
-			}
-		}
-		stack++;
-	}
-	return bp;
-}
+#include "dumpstack.h"
 
 void dump_trace(struct task_struct *task, struct pt_regs *regs,
 		unsigned long *stack, unsigned long bp,
 		const struct stacktrace_ops *ops, void *data)
 {
+	int graph = 0;
+
 	if (!task)
 		task = current;
 
@@ -107,7 +52,8 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs,
 
 		context = (struct thread_info *)
 			((unsigned long)stack & (~(THREAD_SIZE - 1)));
-		bp = print_context_stack(context, stack, bp, ops, data, NULL);
+		bp = print_context_stack(context, stack, bp, ops,
+					 data, NULL, &graph);
 
 		stack = (unsigned long *)context->previous_esp;
 		if (!stack)
@@ -119,57 +65,7 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs,
 }
 EXPORT_SYMBOL(dump_trace);
 
-static void
-print_trace_warning_symbol(void *data, char *msg, unsigned long symbol)
-{
-	printk(data);
-	print_symbol(msg, symbol);
-	printk("\n");
-}
-
-static void print_trace_warning(void *data, char *msg)
-{
-	printk("%s%s\n", (char *)data, msg);
-}
-
-static int print_trace_stack(void *data, char *name)
-{
-	printk("%s <%s> ", (char *)data, name);
-	return 0;
-}
-
-/*
- * Print one address/symbol entries per line.
- */
-static void print_trace_address(void *data, unsigned long addr, int reliable)
-{
-	touch_nmi_watchdog();
-	printk(data);
-	printk_address(addr, reliable);
-}
-
-static const struct stacktrace_ops print_trace_ops = {
-	.warning = print_trace_warning,
-	.warning_symbol = print_trace_warning_symbol,
-	.stack = print_trace_stack,
-	.address = print_trace_address,
-};
-
-static void
-show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
-		unsigned long *stack, unsigned long bp, char *log_lvl)
-{
-	printk("%sCall Trace:\n", log_lvl);
-	dump_trace(task, regs, stack, bp, &print_trace_ops, log_lvl);
-}
-
-void show_trace(struct task_struct *task, struct pt_regs *regs,
-		unsigned long *stack, unsigned long bp)
-{
-	show_trace_log_lvl(task, regs, stack, bp, "");
-}
-
-static void
+void
 show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
 		unsigned long *sp, unsigned long bp, char *log_lvl)
 {
@@ -196,33 +92,6 @@ show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
 	show_trace_log_lvl(task, regs, sp, bp, log_lvl);
 }
 
-void show_stack(struct task_struct *task, unsigned long *sp)
-{
-	show_stack_log_lvl(task, NULL, sp, 0, "");
-}
-
-/*
- * The architecture-independent dump_stack generator
- */
-void dump_stack(void)
-{
-	unsigned long bp = 0;
-	unsigned long stack;
-
-#ifdef CONFIG_FRAME_POINTER
-	if (!bp)
-		get_bp(bp);
-#endif
-
-	printk("Pid: %d, comm: %.20s %s %s %.*s\n",
-		current->pid, current->comm, print_tainted(),
-		init_utsname()->release,
-		(int)strcspn(init_utsname()->version, " "),
-		init_utsname()->version);
-	show_trace(NULL, NULL, &stack, bp);
-}
-
-EXPORT_SYMBOL(dump_stack);
 
 void show_registers(struct pt_regs *regs)
 {
@@ -283,167 +152,3 @@ int is_valid_bugaddr(unsigned long ip)
 	return ud2 == 0x0b0f;
 }
 
-static raw_spinlock_t die_lock = __RAW_SPIN_LOCK_UNLOCKED;
-static int die_owner = -1;
-static unsigned int die_nest_count;
-
-unsigned __kprobes long oops_begin(void)
-{
-	unsigned long flags;
-
-	oops_enter();
-
-	if (die_owner != raw_smp_processor_id()) {
-		console_verbose();
-		raw_local_irq_save(flags);
-		__raw_spin_lock(&die_lock);
-		die_owner = smp_processor_id();
-		die_nest_count = 0;
-		bust_spinlocks(1);
-	} else {
-		raw_local_irq_save(flags);
-	}
-	die_nest_count++;
-	return flags;
-}
-
-void __kprobes oops_end(unsigned long flags, struct pt_regs *regs, int signr)
-{
-	bust_spinlocks(0);
-	die_owner = -1;
-	add_taint(TAINT_DIE);
-	__raw_spin_unlock(&die_lock);
-	raw_local_irq_restore(flags);
-
-	if (!regs)
-		return;
-
-	if (kexec_should_crash(current))
-		crash_kexec(regs);
-	if (in_interrupt())
-		panic("Fatal exception in interrupt");
-	if (panic_on_oops)
-		panic("Fatal exception");
-	oops_exit();
-	do_exit(signr);
-}
-
-int __kprobes __die(const char *str, struct pt_regs *regs, long err)
-{
-	unsigned short ss;
-	unsigned long sp;
-
-	printk(KERN_EMERG "%s: %04lx [#%d] ", str, err & 0xffff, ++die_counter);
-#ifdef CONFIG_PREEMPT
-	printk("PREEMPT ");
-#endif
-#ifdef CONFIG_SMP
-	printk("SMP ");
-#endif
-#ifdef CONFIG_DEBUG_PAGEALLOC
-	printk("DEBUG_PAGEALLOC");
-#endif
-	printk("\n");
-	sysfs_printk_last_file();
-	if (notify_die(DIE_OOPS, str, regs, err,
-			current->thread.trap_no, SIGSEGV) == NOTIFY_STOP)
-		return 1;
-
-	show_registers(regs);
-	/* Executive summary in case the oops scrolled away */
-	sp = (unsigned long) (&regs->sp);
-	savesegment(ss, ss);
-	if (user_mode(regs)) {
-		sp = regs->sp;
-		ss = regs->ss & 0xffff;
-	}
-	printk(KERN_EMERG "EIP: [<%08lx>] ", regs->ip);
-	print_symbol("%s", regs->ip);
-	printk(" SS:ESP %04x:%08lx\n", ss, sp);
-	return 0;
-}
-
-/*
- * This is gone through when something in the kernel has done something bad
- * and is about to be terminated:
- */
-void die(const char *str, struct pt_regs *regs, long err)
-{
-	unsigned long flags = oops_begin();
-
-	if (die_nest_count < 3) {
-		report_bug(regs->ip, regs);
-
-		if (__die(str, regs, err))
-			regs = NULL;
-	} else {
-		printk(KERN_EMERG "Recursive die() failure, output suppressed\n");
-	}
-
-	oops_end(flags, regs, SIGSEGV);
-}
-
-static DEFINE_SPINLOCK(nmi_print_lock);
-
-void notrace __kprobes
-die_nmi(char *str, struct pt_regs *regs, int do_panic)
-{
-	if (notify_die(DIE_NMIWATCHDOG, str, regs, 0, 2, SIGINT) == NOTIFY_STOP)
-		return;
-
-	spin_lock(&nmi_print_lock);
-	/*
-	* We are in trouble anyway, lets at least try
-	* to get a message out:
-	*/
-	bust_spinlocks(1);
-	printk(KERN_EMERG "%s", str);
-	printk(" on CPU%d, ip %08lx, registers:\n",
-		smp_processor_id(), regs->ip);
-	show_registers(regs);
-	if (do_panic)
-		panic("Non maskable interrupt");
-	console_silent();
-	spin_unlock(&nmi_print_lock);
-
-	/*
-	 * If we are in kernel we are probably nested up pretty bad
-	 * and might aswell get out now while we still can:
-	 */
-	if (!user_mode_vm(regs)) {
-		current->thread.trap_no = 2;
-		crash_kexec(regs);
-	}
-
-	bust_spinlocks(0);
-	do_exit(SIGSEGV);
-}
-
-static int __init oops_setup(char *s)
-{
-	if (!s)
-		return -EINVAL;
-	if (!strcmp(s, "panic"))
-		panic_on_oops = 1;
-	return 0;
-}
-early_param("oops", oops_setup);
-
-static int __init kstack_setup(char *s)
-{
-	if (!s)
-		return -EINVAL;
-	kstack_depth_to_print = simple_strtoul(s, NULL, 0);
-	return 0;
-}
-early_param("kstack", kstack_setup);
-
-static int __init code_bytes_setup(char *s)
-{
-	code_bytes = simple_strtoul(s, NULL, 0);
-	if (code_bytes > 8192)
-		code_bytes = 8192;
-
-	return 1;
-}
-__setup("code_bytes=", code_bytes_setup);

arch/x86/kernel/dumpstack_64.c

@@ -17,19 +17,7 @@
 
 #include <asm/stacktrace.h>
 
-#define STACKSLOTS_PER_LINE 4
-#define get_bp(bp) asm("movq %%rbp, %0" : "=r" (bp) :)
-
-int panic_on_unrecovered_nmi;
-int kstack_depth_to_print = 3 * STACKSLOTS_PER_LINE;
-static unsigned int code_bytes = 64;
-static int die_counter;
-
-void printk_address(unsigned long address, int reliable)
-{
-	printk(" [<%p>] %s%pS\n", (void *) address,
-			reliable ? "" : "? ", (void *) address);
-}
+#include "dumpstack.h"
 
 static unsigned long *in_exception_stack(unsigned cpu, unsigned long stack,
 					unsigned *usedp, char **idp)
@@ -113,51 +101,6 @@ static unsigned long *in_exception_stack(unsigned cpu, unsigned long stack,
  * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
  */
 
-static inline int valid_stack_ptr(struct thread_info *tinfo,
-			void *p, unsigned int size, void *end)
-{
-	void *t = tinfo;
-	if (end) {
-		if (p < end && p >= (end-THREAD_SIZE))
-			return 1;
-		else
-			return 0;
-	}
-	return p > t && p < t + THREAD_SIZE - size;
-}
-
-/* The form of the top of the frame on the stack */
-struct stack_frame {
-	struct stack_frame *next_frame;
-	unsigned long return_address;
-};
-
-static inline unsigned long
-print_context_stack(struct thread_info *tinfo,
-		unsigned long *stack, unsigned long bp,
-		const struct stacktrace_ops *ops, void *data,
-		unsigned long *end)
-{
-	struct stack_frame *frame = (struct stack_frame *)bp;
-
-	while (valid_stack_ptr(tinfo, stack, sizeof(*stack), end)) {
-		unsigned long addr;
-
-		addr = *stack;
-		if (__kernel_text_address(addr)) {
-			if ((unsigned long) stack == bp + sizeof(long)) {
-				ops->address(data, addr, 1);
-				frame = frame->next_frame;
-				bp = (unsigned long) frame;
-			} else {
-				ops->address(data, addr, bp == 0);
-			}
-		}
-		stack++;
-	}
-	return bp;
-}
-
 void dump_trace(struct task_struct *task, struct pt_regs *regs,
 		unsigned long *stack, unsigned long bp,
 		const struct stacktrace_ops *ops, void *data)
@@ -166,6 +109,7 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs,
 	unsigned long *irqstack_end = (unsigned long *)cpu_pda(cpu)->irqstackptr;
 	unsigned used = 0;
 	struct thread_info *tinfo;
+	int graph = 0;
 
 	if (!task)
 		task = current;
@@ -206,7 +150,7 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs,
 				break;
 
 			bp = print_context_stack(tinfo, stack, bp, ops,
-							data, estack_end);
+						 data, estack_end, &graph);
 			ops->stack(data, "<EOE>");
 			/*
 			 * We link to the next stack via the
@@ -225,7 +169,7 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs,
 				if (ops->stack(data, "IRQ") < 0)
 					break;
 				bp = print_context_stack(tinfo, stack, bp,
-						ops, data, irqstack_end);
+					ops, data, irqstack_end, &graph);
 				/*
 				 * We link to the next stack (which would be
 				 * the process stack normally) the last
@@ -243,62 +187,12 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs,
 	/*
 	 * This handles the process stack:
 	 */
-	bp = print_context_stack(tinfo, stack, bp, ops, data, NULL);
+	bp = print_context_stack(tinfo, stack, bp, ops, data, NULL, &graph);
 	put_cpu();
 }
 EXPORT_SYMBOL(dump_trace);
 
-static void
-print_trace_warning_symbol(void *data, char *msg, unsigned long symbol)
-{
-	printk(data);
-	print_symbol(msg, symbol);
-	printk("\n");
-}
-
-static void print_trace_warning(void *data, char *msg)
-{
-	printk("%s%s\n", (char *)data, msg);
-}
-
-static int print_trace_stack(void *data, char *name)
-{
-	printk("%s <%s> ", (char *)data, name);
-	return 0;
-}
-
-/*
- * Print one address/symbol entries per line.
- */
-static void print_trace_address(void *data, unsigned long addr, int reliable)
-{
-	touch_nmi_watchdog();
-	printk(data);
-	printk_address(addr, reliable);
-}
-
-static const struct stacktrace_ops print_trace_ops = {
-	.warning = print_trace_warning,
-	.warning_symbol = print_trace_warning_symbol,
-	.stack = print_trace_stack,
-	.address = print_trace_address,
-};
-
-static void
-show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
-		unsigned long *stack, unsigned long bp, char *log_lvl)
-{
-	printk("%sCall Trace:\n", log_lvl);
-	dump_trace(task, regs, stack, bp, &print_trace_ops, log_lvl);
-}
-
-void show_trace(struct task_struct *task, struct pt_regs *regs,
-		unsigned long *stack, unsigned long bp)
-{
-	show_trace_log_lvl(task, regs, stack, bp, "");
-}
-
-static void
+void
 show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
 		unsigned long *sp, unsigned long bp, char *log_lvl)
 {
@@ -342,33 +236,6 @@ show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
 	show_trace_log_lvl(task, regs, sp, bp, log_lvl);
 }
 
-void show_stack(struct task_struct *task, unsigned long *sp)
-{
-	show_stack_log_lvl(task, NULL, sp, 0, "");
-}
-
-/*
- * The architecture-independent dump_stack generator
- */
-void dump_stack(void)
-{
-	unsigned long bp = 0;
-	unsigned long stack;
-
-#ifdef CONFIG_FRAME_POINTER
-	if (!bp)
-		get_bp(bp);
-#endif
-
-	printk("Pid: %d, comm: %.20s %s %s %.*s\n",
-		current->pid, current->comm, print_tainted(),
-		init_utsname()->release,
-		(int)strcspn(init_utsname()->version, " "),
-		init_utsname()->version);
-	show_trace(NULL, NULL, &stack, bp);
-}
-EXPORT_SYMBOL(dump_stack);
-
 void show_registers(struct pt_regs *regs)
 {
 	int i;
@@ -429,147 +296,3 @@ int is_valid_bugaddr(unsigned long ip)
 	return ud2 == 0x0b0f;
 }
 
-static raw_spinlock_t die_lock = __RAW_SPIN_LOCK_UNLOCKED;
-static int die_owner = -1;
-static unsigned int die_nest_count;
-
-unsigned __kprobes long oops_begin(void)
-{
-	int cpu;
-	unsigned long flags;
-
-	oops_enter();
-
-	/* racy, but better than risking deadlock. */
-	raw_local_irq_save(flags);
-	cpu = smp_processor_id();
-	if (!__raw_spin_trylock(&die_lock)) {
-		if (cpu == die_owner)
-			/* nested oops. should stop eventually */;
-		else
-			__raw_spin_lock(&die_lock);
-	}
-	die_nest_count++;
-	die_owner = cpu;
-	console_verbose();
-	bust_spinlocks(1);
-	return flags;
-}
-
-void __kprobes oops_end(unsigned long flags, struct pt_regs *regs, int signr)
-{
-	die_owner = -1;
-	bust_spinlocks(0);
-	die_nest_count--;
-	if (!die_nest_count)
-		/* Nest count reaches zero, release the lock. */
-		__raw_spin_unlock(&die_lock);
-	raw_local_irq_restore(flags);
-	if (!regs) {
-		oops_exit();
-		return;
-	}
-	if (in_interrupt())
-		panic("Fatal exception in interrupt");
-	if (panic_on_oops)
-		panic("Fatal exception");
-	oops_exit();
-	do_exit(signr);
-}
-
-int __kprobes __die(const char *str, struct pt_regs *regs, long err)
-{
-	printk(KERN_EMERG "%s: %04lx [#%d] ", str, err & 0xffff, ++die_counter);
-#ifdef CONFIG_PREEMPT
-	printk("PREEMPT ");
-#endif
-#ifdef CONFIG_SMP
-	printk("SMP ");
-#endif
-#ifdef CONFIG_DEBUG_PAGEALLOC
-	printk("DEBUG_PAGEALLOC");
-#endif
-	printk("\n");
-	sysfs_printk_last_file();
-	if (notify_die(DIE_OOPS, str, regs, err,
-			current->thread.trap_no, SIGSEGV) == NOTIFY_STOP)
-		return 1;
-
-	show_registers(regs);
-	add_taint(TAINT_DIE);
-	/* Executive summary in case the oops scrolled away */
-	printk(KERN_ALERT "RIP ");
-	printk_address(regs->ip, 1);
-	printk(" RSP <%016lx>\n", regs->sp);
-	if (kexec_should_crash(current))
-		crash_kexec(regs);
-	return 0;
-}
-
-void die(const char *str, struct pt_regs *regs, long err)
-{
-	unsigned long flags = oops_begin();
-
-	if (!user_mode(regs))
-		report_bug(regs->ip, regs);
-
-	if (__die(str, regs, err))
-		regs = NULL;
-	oops_end(flags, regs, SIGSEGV);
-}
-
-notrace __kprobes void
-die_nmi(char *str, struct pt_regs *regs, int do_panic)
-{
-	unsigned long flags;
-
-	if (notify_die(DIE_NMIWATCHDOG, str, regs, 0, 2, SIGINT) == NOTIFY_STOP)
-		return;
-
-	flags = oops_begin();
-	/*
-	 * We are in trouble anyway, lets at least try
-	 * to get a message out.
-	 */
-	printk(KERN_EMERG "%s", str);
-	printk(" on CPU%d, ip %08lx, registers:\n",
-		smp_processor_id(), regs->ip);
-	show_registers(regs);
-	if (kexec_should_crash(current))
-		crash_kexec(regs);
-	if (do_panic || panic_on_oops)
-		panic("Non maskable interrupt");
-	oops_end(flags, NULL, SIGBUS);
-	nmi_exit();
-	local_irq_enable();
-	do_exit(SIGBUS);
-}
-
-static int __init oops_setup(char *s)
-{
-	if (!s)
-		return -EINVAL;
-	if (!strcmp(s, "panic"))
-		panic_on_oops = 1;
-	return 0;
-}
-early_param("oops", oops_setup);
-
-static int __init kstack_setup(char *s)
-{
-	if (!s)
-		return -EINVAL;
-	kstack_depth_to_print = simple_strtoul(s, NULL, 0);
-	return 0;
-}
-early_param("kstack", kstack_setup);
-
-static int __init code_bytes_setup(char *s)
-{
-	code_bytes = simple_strtoul(s, NULL, 0);
-	if (code_bytes > 8192)
-		code_bytes = 8192;
-
-	return 1;
-}
-__setup("code_bytes=", code_bytes_setup);

arch/x86/kernel/entry_32.S

@@ -1196,6 +1196,9 @@ ENTRY(mcount)
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 	cmpl $ftrace_stub, ftrace_graph_return
 	jnz ftrace_graph_caller
+
+	cmpl $ftrace_graph_entry_stub, ftrace_graph_entry
+	jnz ftrace_graph_caller
 #endif
 .globl ftrace_stub
 ftrace_stub:
@@ -1230,6 +1233,7 @@ ENTRY(ftrace_graph_caller)
 	pushl %edx
 	movl 0xc(%esp), %edx
 	lea 0x4(%ebp), %eax
+	subl $MCOUNT_INSN_SIZE, %edx
 	call prepare_ftrace_return
 	popl %edx
 	popl %ecx

arch/x86/kernel/entry_64.S

@@ -120,6 +120,9 @@ ENTRY(mcount)
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 	cmpq $ftrace_stub, ftrace_graph_return
 	jnz ftrace_graph_caller
+
+	cmpq $ftrace_graph_entry_stub, ftrace_graph_entry
+	jnz ftrace_graph_caller
 #endif
 
 .globl ftrace_stub
@@ -173,6 +176,7 @@ ENTRY(ftrace_graph_caller)
 
 	leaq 8(%rbp), %rdi
 	movq 0x38(%rsp), %rsi
+	subq $MCOUNT_INSN_SIZE, %rsi
 
 	call	prepare_ftrace_return
 

arch/x86/kernel/ftrace.c

@@ -420,12 +420,23 @@ static void pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret)
 	int index;
 
 	index = current->curr_ret_stack;
+
+	if (unlikely(index < 0)) {
+		ftrace_graph_stop();
+		WARN_ON(1);
+		/* Might as well panic, otherwise we have no where to go */
+		*ret = (unsigned long)panic;
+		return;
+	}
+
 	*ret = current->ret_stack[index].ret;
 	trace->func = current->ret_stack[index].func;
 	trace->calltime = current->ret_stack[index].calltime;
 	trace->overrun = atomic_read(&current->trace_overrun);
 	trace->depth = index;
+	barrier();
 	current->curr_ret_stack--;
+
 }
 
 /*
@@ -441,6 +452,13 @@ unsigned long ftrace_return_to_handler(void)
 	trace.rettime = cpu_clock(raw_smp_processor_id());
 	ftrace_graph_return(&trace);
 
+	if (unlikely(!ret)) {
+		ftrace_graph_stop();
+		WARN_ON(1);
+		/* Might as well panic. What else to do? */
+		ret = (unsigned long)panic;
+	}
+
 	return ret;
 }
 
@@ -467,28 +485,16 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
 	 * ignore such a protection.
 	 */
 	asm volatile(
-#ifdef CONFIG_X86_64
-		"1: movq (%[parent_old]), %[old]\n"
-		"2: movq %[return_hooker], (%[parent_replaced])\n"
-#else
-		"1: movl (%[parent_old]), %[old]\n"
-		"2: movl %[return_hooker], (%[parent_replaced])\n"
-#endif
+		"1: " _ASM_MOV " (%[parent_old]), %[old]\n"
+		"2: " _ASM_MOV " %[return_hooker], (%[parent_replaced])\n"
 		"   movl $0, %[faulted]\n"
 
 		".section .fixup, \"ax\"\n"
 		"3: movl $1, %[faulted]\n"
 		".previous\n"
 
-		".section __ex_table, \"a\"\n"
-#ifdef CONFIG_X86_64
-		"   .quad 1b, 3b\n"
-		"   .quad 2b, 3b\n"
-#else
-		"   .long 1b, 3b\n"
-		"   .long 2b, 3b\n"
-#endif
-		".previous\n"
+		_ASM_EXTABLE(1b, 3b)
+		_ASM_EXTABLE(2b, 3b)
 
 		: [parent_replaced] "=r" (parent), [old] "=r" (old),
 		  [faulted] "=r" (faulted)
@@ -496,14 +502,16 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
 		: "memory"
 	);
 
-	if (WARN_ON(faulted)) {
-		unregister_ftrace_graph();
+	if (unlikely(faulted)) {
+		ftrace_graph_stop();
+		WARN_ON(1);
 		return;
 	}
 
-	if (WARN_ON(!__kernel_text_address(old))) {
-		unregister_ftrace_graph();
+	if (unlikely(!__kernel_text_address(old))) {
+		ftrace_graph_stop();
 		*parent = old;
+		WARN_ON(1);
 		return;
 	}
 
@@ -516,7 +524,11 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
 	}
 
 	trace.func = self_addr;
-	ftrace_graph_entry(&trace);
 
+	/* Only trace if the calling function expects to */
+	if (!ftrace_graph_entry(&trace)) {
+		current->curr_ret_stack--;
+		*parent = old;
+	}
 }
 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */

arch/x86/mm/fault.c

@@ -413,6 +413,7 @@ static noinline void pgtable_bad(unsigned long address, struct pt_regs *regs,
 				 unsigned long error_code)
 {
 	unsigned long flags = oops_begin();
+	int sig = SIGKILL;
 	struct task_struct *tsk;
 
 	printk(KERN_ALERT "%s: Corrupted page table at address %lx\n",
@@ -423,8 +424,8 @@ static noinline void pgtable_bad(unsigned long address, struct pt_regs *regs,
 	tsk->thread.trap_no = 14;
 	tsk->thread.error_code = error_code;
 	if (__die("Bad pagetable", regs, error_code))
-		regs = NULL;
-	oops_end(flags, regs, SIGKILL);
+		sig = 0;
+	oops_end(flags, regs, sig);
 }
 #endif
 
@@ -590,6 +591,7 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code)
 	int fault;
 #ifdef CONFIG_X86_64
 	unsigned long flags;
+	int sig;
 #endif
 
 	tsk = current;
@@ -849,11 +851,12 @@ no_context:
 	bust_spinlocks(0);
 	do_exit(SIGKILL);
 #else
+	sig = SIGKILL;
 	if (__die("Oops", regs, error_code))
-		regs = NULL;
+		sig = 0;
 	/* Executive summary in case the body of the oops scrolled away */
 	printk(KERN_EMERG "CR2: %016lx\n", address);
-	oops_end(flags, regs, SIGKILL);
+	oops_end(flags, regs, sig);
 #endif
 
 /*

include/linux/ftrace.h

@@ -371,11 +371,13 @@ struct ftrace_graph_ret {
 #define FTRACE_RETSTACK_ALLOC_SIZE 32
 /* Type of the callback handlers for tracing function graph*/
 typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */
-typedef void (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */
+typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */
 
 extern int register_ftrace_graph(trace_func_graph_ret_t retfunc,
 				trace_func_graph_ent_t entryfunc);
 
+extern void ftrace_graph_stop(void);
+
 /* The current handlers in use */
 extern trace_func_graph_ret_t ftrace_graph_return;
 extern trace_func_graph_ent_t ftrace_graph_entry;

include/linux/ring_buffer.h

@@ -124,6 +124,11 @@ void tracing_on(void);
 void tracing_off(void);
 void tracing_off_permanent(void);
 
+void *ring_buffer_alloc_read_page(struct ring_buffer *buffer);
+void ring_buffer_free_read_page(struct ring_buffer *buffer, void *data);
+int ring_buffer_read_page(struct ring_buffer *buffer,
+			  void **data_page, int cpu, int full);
+
 enum ring_buffer_flags {
 	RB_FL_OVERWRITE		= 1 << 0,
 };

kernel/fork.c

@@ -1137,6 +1137,8 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 		}
 	}
 
+	ftrace_graph_init_task(p);
+
 	p->pid = pid_nr(pid);
 	p->tgid = p->pid;
 	if (clone_flags & CLONE_THREAD)
@@ -1145,7 +1147,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 	if (current->nsproxy != p->nsproxy) {
 		retval = ns_cgroup_clone(p, pid);
 		if (retval)
-			goto bad_fork_free_pid;
+			goto bad_fork_free_graph;
 	}
 
 	p->set_child_tid = (clone_flags & CLONE_CHILD_SETTID) ? child_tidptr : NULL;
@@ -1238,7 +1240,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 		spin_unlock(&current->sighand->siglock);
 		write_unlock_irq(&tasklist_lock);
 		retval = -ERESTARTNOINTR;
-		goto bad_fork_free_pid;
+		goto bad_fork_free_graph;
 	}
 
 	if (clone_flags & CLONE_THREAD) {
@@ -1271,11 +1273,12 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 	total_forks++;
 	spin_unlock(&current->sighand->siglock);
 	write_unlock_irq(&tasklist_lock);
-	ftrace_graph_init_task(p);
 	proc_fork_connector(p);
 	cgroup_post_fork(p);
 	return p;
 
+bad_fork_free_graph:
+	ftrace_graph_exit_task(p);
 bad_fork_free_pid:
 	if (pid != &init_struct_pid)
 		free_pid(pid);

kernel/lockdep.c

@@ -25,6 +25,7 @@
  * Thanks to Arjan van de Ven for coming up with the initial idea of
  * mapping lock dependencies runtime.
  */
+#define DISABLE_BRANCH_PROFILING
 #include <linux/mutex.h>
 #include <linux/sched.h>
 #include <linux/delay.h>

kernel/trace/Kconfig

@@ -67,6 +67,7 @@ config FUNCTION_GRAPH_TRACER
 	bool "Kernel Function Graph Tracer"
 	depends on HAVE_FUNCTION_GRAPH_TRACER
 	depends on FUNCTION_TRACER
+	default y
 	help
 	  Enable the kernel to trace a function at both its return
 	  and its entry.

kernel/trace/ftrace.c

@@ -1636,11 +1636,15 @@ ftrace_enable_sysctl(struct ctl_table *table, int write,
 
 static atomic_t ftrace_graph_active;
 
+int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace)
+{
+	return 0;
+}
+
 /* The callbacks that hook a function */
 trace_func_graph_ret_t ftrace_graph_return =
 			(trace_func_graph_ret_t)ftrace_stub;
-trace_func_graph_ent_t ftrace_graph_entry =
-			(trace_func_graph_ent_t)ftrace_stub;
+trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub;
 
 /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */
 static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list)
@@ -1738,7 +1742,7 @@ void unregister_ftrace_graph(void)
 
 	atomic_dec(&ftrace_graph_active);
 	ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub;
-	ftrace_graph_entry = (trace_func_graph_ent_t)ftrace_stub;
+	ftrace_graph_entry = ftrace_graph_entry_stub;
 	ftrace_shutdown(FTRACE_STOP_FUNC_RET);
 
 	mutex_unlock(&ftrace_sysctl_lock);
@@ -1769,5 +1773,10 @@ void ftrace_graph_exit_task(struct task_struct *t)
 
 	kfree(ret_stack);
 }
+
+void ftrace_graph_stop(void)
+{
+	ftrace_stop();
+}
 #endif
 

kernel/trace/ring_buffer.c

@@ -195,20 +195,24 @@ void *ring_buffer_event_data(struct ring_buffer_event *event)
 #define TS_MASK		((1ULL << TS_SHIFT) - 1)
 #define TS_DELTA_TEST	(~TS_MASK)
 
-/*
- * This hack stolen from mm/slob.c.
- * We can store per page timing information in the page frame of the page.
- * Thanks to Peter Zijlstra for suggesting this idea.
- */
-struct buffer_page {
+struct buffer_data_page {
 	u64		 time_stamp;	/* page time stamp */
-	local_t		 write;		/* index for next write */
 	local_t		 commit;	/* write commited index */
+	unsigned char	 data[];	/* data of buffer page */
+};
+
+struct buffer_page {
+	local_t		 write;		/* index for next write */
 	unsigned	 read;		/* index for next read */
 	struct list_head list;		/* list of free pages */
-	void *page;			/* Actual data page */
+	struct buffer_data_page *page;	/* Actual data page */
 };
 
+static void rb_init_page(struct buffer_data_page *bpage)
+{
+	local_set(&bpage->commit, 0);
+}
+
 /*
  * Also stolen from mm/slob.c. Thanks to Mathieu Desnoyers for pointing
  * this issue out.
@@ -230,7 +234,7 @@ static inline int test_time_stamp(u64 delta)
 	return 0;
 }
 
-#define BUF_PAGE_SIZE PAGE_SIZE
+#define BUF_PAGE_SIZE (PAGE_SIZE - sizeof(struct buffer_data_page))
 
 /*
  * head_page == tail_page && head == tail then buffer is empty.
@@ -294,19 +298,19 @@ struct ring_buffer_iter {
 static int rb_check_pages(struct ring_buffer_per_cpu *cpu_buffer)
 {
 	struct list_head *head = &cpu_buffer->pages;
-	struct buffer_page *page, *tmp;
+	struct buffer_page *bpage, *tmp;
 
 	if (RB_WARN_ON(cpu_buffer, head->next->prev != head))
 		return -1;
 	if (RB_WARN_ON(cpu_buffer, head->prev->next != head))
 		return -1;
 
-	list_for_each_entry_safe(page, tmp, head, list) {
+	list_for_each_entry_safe(bpage, tmp, head, list) {
 		if (RB_WARN_ON(cpu_buffer,
-			       page->list.next->prev != &page->list))
+			       bpage->list.next->prev != &bpage->list))
 			return -1;
 		if (RB_WARN_ON(cpu_buffer,
-			       page->list.prev->next != &page->list))
+			       bpage->list.prev->next != &bpage->list))
 			return -1;
 	}
 
@@ -317,22 +321,23 @@ static int rb_allocate_pages(struct ring_buffer_per_cpu *cpu_buffer,
 			     unsigned nr_pages)
 {
 	struct list_head *head = &cpu_buffer->pages;
-	struct buffer_page *page, *tmp;
+	struct buffer_page *bpage, *tmp;
 	unsigned long addr;
 	LIST_HEAD(pages);
 	unsigned i;
 
 	for (i = 0; i < nr_pages; i++) {
-		page = kzalloc_node(ALIGN(sizeof(*page), cache_line_size()),
+		bpage = kzalloc_node(ALIGN(sizeof(*bpage), cache_line_size()),
 				    GFP_KERNEL, cpu_to_node(cpu_buffer->cpu));
-		if (!page)
+		if (!bpage)
 			goto free_pages;
-		list_add(&page->list, &pages);
+		list_add(&bpage->list, &pages);
 
 		addr = __get_free_page(GFP_KERNEL);
 		if (!addr)
 			goto free_pages;
-		page->page = (void *)addr;
+		bpage->page = (void *)addr;
+		rb_init_page(bpage->page);
 	}
 
 	list_splice(&pages, head);
@@ -342,9 +347,9 @@ static int rb_allocate_pages(struct ring_buffer_per_cpu *cpu_buffer,
 	return 0;
 
  free_pages:
-	list_for_each_entry_safe(page, tmp, &pages, list) {
-		list_del_init(&page->list);
-		free_buffer_page(page);
+	list_for_each_entry_safe(bpage, tmp, &pages, list) {
+		list_del_init(&bpage->list);
+		free_buffer_page(bpage);
 	}
 	return -ENOMEM;
 }
@@ -353,7 +358,7 @@ static struct ring_buffer_per_cpu *
 rb_allocate_cpu_buffer(struct ring_buffer *buffer, int cpu)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
-	struct buffer_page *page;
+	struct buffer_page *bpage;
 	unsigned long addr;
 	int ret;
 
@@ -368,16 +373,17 @@ rb_allocate_cpu_buffer(struct ring_buffer *buffer, int cpu)
 	cpu_buffer->lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
 	INIT_LIST_HEAD(&cpu_buffer->pages);
 
-	page = kzalloc_node(ALIGN(sizeof(*page), cache_line_size()),
+	bpage = kzalloc_node(ALIGN(sizeof(*bpage), cache_line_size()),
 			    GFP_KERNEL, cpu_to_node(cpu));
-	if (!page)
+	if (!bpage)
 		goto fail_free_buffer;
 
-	cpu_buffer->reader_page = page;
+	cpu_buffer->reader_page = bpage;
 	addr = __get_free_page(GFP_KERNEL);
 	if (!addr)
 		goto fail_free_reader;
-	page->page = (void *)addr;
+	bpage->page = (void *)addr;
+	rb_init_page(bpage->page);
 
 	INIT_LIST_HEAD(&cpu_buffer->reader_page->list);
 
@@ -402,14 +408,14 @@ rb_allocate_cpu_buffer(struct ring_buffer *buffer, int cpu)
 static void rb_free_cpu_buffer(struct ring_buffer_per_cpu *cpu_buffer)
 {
 	struct list_head *head = &cpu_buffer->pages;
-	struct buffer_page *page, *tmp;
+	struct buffer_page *bpage, *tmp;
 
 	list_del_init(&cpu_buffer->reader_page->list);
 	free_buffer_page(cpu_buffer->reader_page);
 
-	list_for_each_entry_safe(page, tmp, head, list) {
-		list_del_init(&page->list);
-		free_buffer_page(page);
+	list_for_each_entry_safe(bpage, tmp, head, list) {
+		list_del_init(&bpage->list);
+		free_buffer_page(bpage);
 	}
 	kfree(cpu_buffer);
 }
@@ -506,7 +512,7 @@ static void rb_reset_cpu(struct ring_buffer_per_cpu *cpu_buffer);
 static void
 rb_remove_pages(struct ring_buffer_per_cpu *cpu_buffer, unsigned nr_pages)
 {
-	struct buffer_page *page;
+	struct buffer_page *bpage;
 	struct list_head *p;
 	unsigned i;
 
@@ -517,9 +523,9 @@ rb_remove_pages(struct ring_buffer_per_cpu *cpu_buffer, unsigned nr_pages)
 		if (RB_WARN_ON(cpu_buffer, list_empty(&cpu_buffer->pages)))
 			return;
 		p = cpu_buffer->pages.next;
-		page = list_entry(p, struct buffer_page, list);
-		list_del_init(&page->list);
-		free_buffer_page(page);
+		bpage = list_entry(p, struct buffer_page, list);
+		list_del_init(&bpage->list);
+		free_buffer_page(bpage);
 	}
 	if (RB_WARN_ON(cpu_buffer, list_empty(&cpu_buffer->pages)))
 		return;
@@ -536,7 +542,7 @@ static void
 rb_insert_pages(struct ring_buffer_per_cpu *cpu_buffer,
 		struct list_head *pages, unsigned nr_pages)
 {
-	struct buffer_page *page;
+	struct buffer_page *bpage;
 	struct list_head *p;
 	unsigned i;
 
@@ -547,9 +553,9 @@ rb_insert_pages(struct ring_buffer_per_cpu *cpu_buffer,
 		if (RB_WARN_ON(cpu_buffer, list_empty(pages)))
 			return;
 		p = pages->next;
-		page = list_entry(p, struct buffer_page, list);
-		list_del_init(&page->list);
-		list_add_tail(&page->list, &cpu_buffer->pages);
+		bpage = list_entry(p, struct buffer_page, list);
+		list_del_init(&bpage->list);
+		list_add_tail(&bpage->list, &cpu_buffer->pages);
 	}
 	rb_reset_cpu(cpu_buffer);
 
@@ -576,7 +582,7 @@ int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	unsigned nr_pages, rm_pages, new_pages;
-	struct buffer_page *page, *tmp;
+	struct buffer_page *bpage, *tmp;
 	unsigned long buffer_size;
 	unsigned long addr;
 	LIST_HEAD(pages);
@@ -637,16 +643,17 @@ int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size)
 
 	for_each_buffer_cpu(buffer, cpu) {
 		for (i = 0; i < new_pages; i++) {
-			page = kzalloc_node(ALIGN(sizeof(*page),
+			bpage = kzalloc_node(ALIGN(sizeof(*bpage),
 						  cache_line_size()),
 					    GFP_KERNEL, cpu_to_node(cpu));
-			if (!page)
+			if (!bpage)
 				goto free_pages;
-			list_add(&page->list, &pages);
+			list_add(&bpage->list, &pages);
 			addr = __get_free_page(GFP_KERNEL);
 			if (!addr)
 				goto free_pages;
-			page->page = (void *)addr;
+			bpage->page = (void *)addr;
+			rb_init_page(bpage->page);
 		}
 	}
 
@@ -667,9 +674,9 @@ int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size)
 	return size;
 
  free_pages:
-	list_for_each_entry_safe(page, tmp, &pages, list) {
-		list_del_init(&page->list);
-		free_buffer_page(page);
+	list_for_each_entry_safe(bpage, tmp, &pages, list) {
+		list_del_init(&bpage->list);
+		free_buffer_page(bpage);
 	}
 	mutex_unlock(&buffer->mutex);
 	return -ENOMEM;
@@ -680,9 +687,15 @@ static inline int rb_null_event(struct ring_buffer_event *event)
 	return event->type == RINGBUF_TYPE_PADDING;
 }
 
-static inline void *__rb_page_index(struct buffer_page *page, unsigned index)
+static inline void *
+__rb_data_page_index(struct buffer_data_page *bpage, unsigned index)
 {
-	return page->page + index;
+	return bpage->data + index;
+}
+
+static inline void *__rb_page_index(struct buffer_page *bpage, unsigned index)
+{
+	return bpage->page->data + index;
 }
 
 static inline struct ring_buffer_event *
@@ -712,7 +725,7 @@ static inline unsigned rb_page_write(struct buffer_page *bpage)
 
 static inline unsigned rb_page_commit(struct buffer_page *bpage)
 {
-	return local_read(&bpage->commit);
+	return local_read(&bpage->page->commit);
 }
 
 /* Size is determined by what has been commited */
@@ -758,14 +771,14 @@ static void rb_update_overflow(struct ring_buffer_per_cpu *cpu_buffer)
 }
 
 static inline void rb_inc_page(struct ring_buffer_per_cpu *cpu_buffer,
-			       struct buffer_page **page)
+			       struct buffer_page **bpage)
 {
-	struct list_head *p = (*page)->list.next;
+	struct list_head *p = (*bpage)->list.next;
 
 	if (p == &cpu_buffer->pages)
 		p = p->next;
 
-	*page = list_entry(p, struct buffer_page, list);
+	*bpage = list_entry(p, struct buffer_page, list);
 }
 
 static inline unsigned
@@ -804,14 +817,15 @@ rb_set_commit_event(struct ring_buffer_per_cpu *cpu_buffer,
 		if (RB_WARN_ON(cpu_buffer,
 			  cpu_buffer->commit_page == cpu_buffer->tail_page))
 			return;
-		cpu_buffer->commit_page->commit =
+		cpu_buffer->commit_page->page->commit =
 			cpu_buffer->commit_page->write;
 		rb_inc_page(cpu_buffer, &cpu_buffer->commit_page);
-		cpu_buffer->write_stamp = cpu_buffer->commit_page->time_stamp;
+		cpu_buffer->write_stamp =
+			cpu_buffer->commit_page->page->time_stamp;
 	}
 
 	/* Now set the commit to the event's index */
-	local_set(&cpu_buffer->commit_page->commit, index);
+	local_set(&cpu_buffer->commit_page->page->commit, index);
 }
 
 static inline void
@@ -826,16 +840,17 @@ rb_set_commit_to_write(struct ring_buffer_per_cpu *cpu_buffer)
 	 * assign the commit to the tail.
 	 */
 	while (cpu_buffer->commit_page != cpu_buffer->tail_page) {
-		cpu_buffer->commit_page->commit =
+		cpu_buffer->commit_page->page->commit =
 			cpu_buffer->commit_page->write;
 		rb_inc_page(cpu_buffer, &cpu_buffer->commit_page);
-		cpu_buffer->write_stamp = cpu_buffer->commit_page->time_stamp;
+		cpu_buffer->write_stamp =
+			cpu_buffer->commit_page->page->time_stamp;
 		/* add barrier to keep gcc from optimizing too much */
 		barrier();
 	}
 	while (rb_commit_index(cpu_buffer) !=
 	       rb_page_write(cpu_buffer->commit_page)) {
-		cpu_buffer->commit_page->commit =
+		cpu_buffer->commit_page->page->commit =
 			cpu_buffer->commit_page->write;
 		barrier();
 	}
@@ -843,7 +858,7 @@ rb_set_commit_to_write(struct ring_buffer_per_cpu *cpu_buffer)
 
 static void rb_reset_reader_page(struct ring_buffer_per_cpu *cpu_buffer)
 {
-	cpu_buffer->read_stamp = cpu_buffer->reader_page->time_stamp;
+	cpu_buffer->read_stamp = cpu_buffer->reader_page->page->time_stamp;
 	cpu_buffer->reader_page->read = 0;
 }
 
@@ -862,7 +877,7 @@ static inline void rb_inc_iter(struct ring_buffer_iter *iter)
 	else
 		rb_inc_page(cpu_buffer, &iter->head_page);
 
-	iter->read_stamp = iter->head_page->time_stamp;
+	iter->read_stamp = iter->head_page->page->time_stamp;
 	iter->head = 0;
 }
 
@@ -998,12 +1013,12 @@ __rb_reserve_next(struct ring_buffer_per_cpu *cpu_buffer,
 		 */
 		if (tail_page == cpu_buffer->tail_page) {
 			local_set(&next_page->write, 0);
-			local_set(&next_page->commit, 0);
+			local_set(&next_page->page->commit, 0);
 			cpu_buffer->tail_page = next_page;
 
 			/* reread the time stamp */
 			*ts = ring_buffer_time_stamp(cpu_buffer->cpu);
-			cpu_buffer->tail_page->time_stamp = *ts;
+			cpu_buffer->tail_page->page->time_stamp = *ts;
 		}
 
 		/*
@@ -1048,7 +1063,7 @@ __rb_reserve_next(struct ring_buffer_per_cpu *cpu_buffer,
 	 * this page's time stamp.
 	 */
 	if (!tail && rb_is_commit(cpu_buffer, event))
-		cpu_buffer->commit_page->time_stamp = *ts;
+		cpu_buffer->commit_page->page->time_stamp = *ts;
 
 	return event;
 
@@ -1099,7 +1114,7 @@ rb_add_time_stamp(struct ring_buffer_per_cpu *cpu_buffer,
 			event->time_delta = *delta & TS_MASK;
 			event->array[0] = *delta >> TS_SHIFT;
 		} else {
-			cpu_buffer->commit_page->time_stamp = *ts;
+			cpu_buffer->commit_page->page->time_stamp = *ts;
 			event->time_delta = 0;
 			event->array[0] = 0;
 		}
@@ -1552,7 +1567,7 @@ static void rb_iter_reset(struct ring_buffer_iter *iter)
 	if (iter->head)
 		iter->read_stamp = cpu_buffer->read_stamp;
 	else
-		iter->read_stamp = iter->head_page->time_stamp;
+		iter->read_stamp = iter->head_page->page->time_stamp;
 }
 
 /**
@@ -1696,7 +1711,7 @@ rb_get_reader_page(struct ring_buffer_per_cpu *cpu_buffer)
 	cpu_buffer->reader_page->list.prev = reader->list.prev;
 
 	local_set(&cpu_buffer->reader_page->write, 0);
-	local_set(&cpu_buffer->reader_page->commit, 0);
+	local_set(&cpu_buffer->reader_page->page->commit, 0);
 
 	/* Make the reader page now replace the head */
 	reader->list.prev->next = &cpu_buffer->reader_page->list;
@@ -2088,7 +2103,7 @@ rb_reset_cpu(struct ring_buffer_per_cpu *cpu_buffer)
 	cpu_buffer->head_page
 		= list_entry(cpu_buffer->pages.next, struct buffer_page, list);
 	local_set(&cpu_buffer->head_page->write, 0);
-	local_set(&cpu_buffer->head_page->commit, 0);
+	local_set(&cpu_buffer->head_page->page->commit, 0);
 
 	cpu_buffer->head_page->read = 0;
 
@@ -2097,7 +2112,7 @@ rb_reset_cpu(struct ring_buffer_per_cpu *cpu_buffer)
 
 	INIT_LIST_HEAD(&cpu_buffer->reader_page->list);
 	local_set(&cpu_buffer->reader_page->write, 0);
-	local_set(&cpu_buffer->reader_page->commit, 0);
+	local_set(&cpu_buffer->reader_page->page->commit, 0);
 	cpu_buffer->reader_page->read = 0;
 
 	cpu_buffer->overrun = 0;
@@ -2223,6 +2238,166 @@ int ring_buffer_swap_cpu(struct ring_buffer *buffer_a,
 	return 0;
 }
 
+static void rb_remove_entries(struct ring_buffer_per_cpu *cpu_buffer,
+			      struct buffer_data_page *bpage)
+{
+	struct ring_buffer_event *event;
+	unsigned long head;
+
+	__raw_spin_lock(&cpu_buffer->lock);
+	for (head = 0; head < local_read(&bpage->commit);
+	     head += rb_event_length(event)) {
+
+		event = __rb_data_page_index(bpage, head);
+		if (RB_WARN_ON(cpu_buffer, rb_null_event(event)))
+			return;
+		/* Only count data entries */
+		if (event->type != RINGBUF_TYPE_DATA)
+			continue;
+		cpu_buffer->entries--;
+	}
+	__raw_spin_unlock(&cpu_buffer->lock);
+}
+
+/**
+ * ring_buffer_alloc_read_page - allocate a page to read from buffer
+ * @buffer: the buffer to allocate for.
+ *
+ * This function is used in conjunction with ring_buffer_read_page.
+ * When reading a full page from the ring buffer, these functions
+ * can be used to speed up the process. The calling function should
+ * allocate a few pages first with this function. Then when it
+ * needs to get pages from the ring buffer, it passes the result
+ * of this function into ring_buffer_read_page, which will swap
+ * the page that was allocated, with the read page of the buffer.
+ *
+ * Returns:
+ *  The page allocated, or NULL on error.
+ */
+void *ring_buffer_alloc_read_page(struct ring_buffer *buffer)
+{
+	unsigned long addr;
+	struct buffer_data_page *bpage;
+
+	addr = __get_free_page(GFP_KERNEL);
+	if (!addr)
+		return NULL;
+
+	bpage = (void *)addr;
+
+	return bpage;
+}
+
+/**
+ * ring_buffer_free_read_page - free an allocated read page
+ * @buffer: the buffer the page was allocate for
+ * @data: the page to free
+ *
+ * Free a page allocated from ring_buffer_alloc_read_page.
+ */
+void ring_buffer_free_read_page(struct ring_buffer *buffer, void *data)
+{
+	free_page((unsigned long)data);
+}
+
+/**
+ * ring_buffer_read_page - extract a page from the ring buffer
+ * @buffer: buffer to extract from
+ * @data_page: the page to use allocated from ring_buffer_alloc_read_page
+ * @cpu: the cpu of the buffer to extract
+ * @full: should the extraction only happen when the page is full.
+ *
+ * This function will pull out a page from the ring buffer and consume it.
+ * @data_page must be the address of the variable that was returned
+ * from ring_buffer_alloc_read_page. This is because the page might be used
+ * to swap with a page in the ring buffer.
+ *
+ * for example:
+ *	rpage = ring_buffer_alloc_page(buffer);
+ *	if (!rpage)
+ *		return error;
+ *	ret = ring_buffer_read_page(buffer, &rpage, cpu, 0);
+ *	if (ret)
+ *		process_page(rpage);
+ *
+ * When @full is set, the function will not return true unless
+ * the writer is off the reader page.
+ *
+ * Note: it is up to the calling functions to handle sleeps and wakeups.
+ *  The ring buffer can be used anywhere in the kernel and can not
+ *  blindly call wake_up. The layer that uses the ring buffer must be
+ *  responsible for that.
+ *
+ * Returns:
+ *  1 if data has been transferred
+ *  0 if no data has been transferred.
+ */
+int ring_buffer_read_page(struct ring_buffer *buffer,
+			    void **data_page, int cpu, int full)
+{
+	struct ring_buffer_per_cpu *cpu_buffer = buffer->buffers[cpu];
+	struct ring_buffer_event *event;
+	struct buffer_data_page *bpage;
+	unsigned long flags;
+	int ret = 0;
+
+	if (!data_page)
+		return 0;
+
+	bpage = *data_page;
+	if (!bpage)
+		return 0;
+
+	spin_lock_irqsave(&cpu_buffer->reader_lock, flags);
+
+	/*
+	 * rb_buffer_peek will get the next ring buffer if
+	 * the current reader page is empty.
+	 */
+	event = rb_buffer_peek(buffer, cpu, NULL);
+	if (!event)
+		goto out;
+
+	/* check for data */
+	if (!local_read(&cpu_buffer->reader_page->page->commit))
+		goto out;
+	/*
+	 * If the writer is already off of the read page, then simply
+	 * switch the read page with the given page. Otherwise
+	 * we need to copy the data from the reader to the writer.
+	 */
+	if (cpu_buffer->reader_page == cpu_buffer->commit_page) {
+		unsigned int read = cpu_buffer->reader_page->read;
+
+		if (full)
+			goto out;
+		/* The writer is still on the reader page, we must copy */
+		bpage = cpu_buffer->reader_page->page;
+		memcpy(bpage->data,
+		       cpu_buffer->reader_page->page->data + read,
+		       local_read(&bpage->commit) - read);
+
+		/* consume what was read */
+		cpu_buffer->reader_page += read;
+
+	} else {
+		/* swap the pages */
+		rb_init_page(bpage);
+		bpage = cpu_buffer->reader_page->page;
+		cpu_buffer->reader_page->page = *data_page;
+		cpu_buffer->reader_page->read = 0;
+		*data_page = bpage;
+	}
+	ret = 1;
+
+	/* update the entry counter */
+	rb_remove_entries(cpu_buffer, bpage);
+ out:
+	spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
+
+	return ret;
+}
+
 static ssize_t
 rb_simple_read(struct file *filp, char __user *ubuf,
 	       size_t cnt, loff_t *ppos)

kernel/trace/trace.c

@@ -1200,7 +1200,7 @@ function_trace_call(unsigned long ip, unsigned long parent_ip)
 }
 
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
-void trace_graph_entry(struct ftrace_graph_ent *trace)
+int trace_graph_entry(struct ftrace_graph_ent *trace)
 {
 	struct trace_array *tr = &global_trace;
 	struct trace_array_cpu *data;
@@ -1209,7 +1209,7 @@ void trace_graph_entry(struct ftrace_graph_ent *trace)
 	int cpu;
 	int pc;
 
-	raw_local_irq_save(flags);
+	local_irq_save(flags);
 	cpu = raw_smp_processor_id();
 	data = tr->data[cpu];
 	disabled = atomic_inc_return(&data->disabled);
@@ -1218,7 +1218,9 @@ void trace_graph_entry(struct ftrace_graph_ent *trace)
 		__trace_graph_entry(tr, data, trace, flags, pc);
 	}
 	atomic_dec(&data->disabled);
-	raw_local_irq_restore(flags);
+	local_irq_restore(flags);
+
+	return 1;
 }
 
 void trace_graph_return(struct ftrace_graph_ret *trace)
@@ -1230,7 +1232,7 @@ void trace_graph_return(struct ftrace_graph_ret *trace)
 	int cpu;
 	int pc;
 
-	raw_local_irq_save(flags);
+	local_irq_save(flags);
 	cpu = raw_smp_processor_id();
 	data = tr->data[cpu];
 	disabled = atomic_inc_return(&data->disabled);
@@ -1239,7 +1241,7 @@ void trace_graph_return(struct ftrace_graph_ret *trace)
 		__trace_graph_return(tr, data, trace, flags, pc);
 	}
 	atomic_dec(&data->disabled);
-	raw_local_irq_restore(flags);
+	local_irq_restore(flags);
 }
 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 
@@ -2645,7 +2647,7 @@ tracing_cpumask_write(struct file *filp, const char __user *ubuf,
 	if (err)
 		goto err_unlock;
 
-	raw_local_irq_disable();
+	local_irq_disable();
 	__raw_spin_lock(&ftrace_max_lock);
 	for_each_tracing_cpu(cpu) {
 		/*
@@ -2662,7 +2664,7 @@ tracing_cpumask_write(struct file *filp, const char __user *ubuf,
 		}
 	}
 	__raw_spin_unlock(&ftrace_max_lock);
-	raw_local_irq_enable();
+	local_irq_enable();
 
 	tracing_cpumask = tracing_cpumask_new;
 

kernel/trace/trace.h

@@ -412,7 +412,7 @@ void trace_function(struct trace_array *tr,
 		    unsigned long flags, int pc);
 
 void trace_graph_return(struct ftrace_graph_ret *trace);
-void trace_graph_entry(struct ftrace_graph_ent *trace);
+int trace_graph_entry(struct ftrace_graph_ent *trace);
 void trace_bts(struct trace_array *tr,
 	       unsigned long from,
 	       unsigned long to);

kernel/trace/trace_branch.c

@@ -42,7 +42,7 @@ probe_likely_condition(struct ftrace_branch_data *f, int val, int expect)
 	if (unlikely(!tr))
 		return;
 
-	raw_local_irq_save(flags);
+	local_irq_save(flags);
 	cpu = raw_smp_processor_id();
 	if (atomic_inc_return(&tr->data[cpu]->disabled) != 1)
 		goto out;
@@ -74,7 +74,7 @@ probe_likely_condition(struct ftrace_branch_data *f, int val, int expect)
 
  out:
 	atomic_dec(&tr->data[cpu]->disabled);
-	raw_local_irq_restore(flags);
+	local_irq_restore(flags);
 }
 
 static inline

kernel/trace/trace_functions_graph.c

@@ -19,6 +19,7 @@
 #define TRACE_GRAPH_PRINT_OVERRUN	0x1
 #define TRACE_GRAPH_PRINT_CPU		0x2
 #define TRACE_GRAPH_PRINT_OVERHEAD	0x4
+#define TRACE_GRAPH_PRINT_PROC		0x8
 
 static struct tracer_opt trace_opts[] = {
 	/* Display overruns ? */
@@ -27,11 +28,13 @@ static struct tracer_opt trace_opts[] = {
 	{ TRACER_OPT(funcgraph-cpu, TRACE_GRAPH_PRINT_CPU) },
 	/* Display Overhead ? */
 	{ TRACER_OPT(funcgraph-overhead, TRACE_GRAPH_PRINT_OVERHEAD) },
+	/* Display proc name/pid */
+	{ TRACER_OPT(funcgraph-proc, TRACE_GRAPH_PRINT_PROC) },
 	{ } /* Empty entry */
 };
 
 static struct tracer_flags tracer_flags = {
-	/* Don't display overruns by default */
+	/* Don't display overruns and proc by default */
 	.val = TRACE_GRAPH_PRINT_CPU | TRACE_GRAPH_PRINT_OVERHEAD,
 	.opts = trace_opts
 };
@@ -104,23 +107,63 @@ print_graph_cpu(struct trace_seq *s, int cpu)
 	return TRACE_TYPE_HANDLED;
 }
 
+#define TRACE_GRAPH_PROCINFO_LENGTH	14
+
+static enum print_line_t
+print_graph_proc(struct trace_seq *s, pid_t pid)
+{
+	int i;
+	int ret;
+	int len;
+	char comm[8];
+	int spaces = 0;
+	/* sign + log10(MAX_INT) + '\0' */
+	char pid_str[11];
+
+	strncpy(comm, trace_find_cmdline(pid), 7);
+	comm[7] = '\0';
+	sprintf(pid_str, "%d", pid);
+
+	/* 1 stands for the "-" character */
+	len = strlen(comm) + strlen(pid_str) + 1;
+
+	if (len < TRACE_GRAPH_PROCINFO_LENGTH)
+		spaces = TRACE_GRAPH_PROCINFO_LENGTH - len;
+
+	/* First spaces to align center */
+	for (i = 0; i < spaces / 2; i++) {
+		ret = trace_seq_printf(s, " ");
+		if (!ret)
+			return TRACE_TYPE_PARTIAL_LINE;
+	}
+
+	ret = trace_seq_printf(s, "%s-%s", comm, pid_str);
+	if (!ret)
+		return TRACE_TYPE_PARTIAL_LINE;
+
+	/* Last spaces to align center */
+	for (i = 0; i < spaces - (spaces / 2); i++) {
+		ret = trace_seq_printf(s, " ");
+		if (!ret)
+			return TRACE_TYPE_PARTIAL_LINE;
+	}
+	return TRACE_TYPE_HANDLED;
+}
+
 
 /* If the pid changed since the last trace, output this event */
-static int verif_pid(struct trace_seq *s, pid_t pid, int cpu)
+static enum print_line_t
+verif_pid(struct trace_seq *s, pid_t pid, int cpu)
 {
-	char *comm, *prev_comm;
 	pid_t prev_pid;
 	int ret;
 
 	if (last_pid[cpu] != -1 && last_pid[cpu] == pid)
-		return 1;
+		return TRACE_TYPE_HANDLED;
 
 	prev_pid = last_pid[cpu];
 	last_pid[cpu] = pid;
 
-	comm = trace_find_cmdline(pid);
-	prev_comm = trace_find_cmdline(prev_pid);
-
 /*
  * Context-switch trace line:
 
@@ -130,11 +173,31 @@ static int verif_pid(struct trace_seq *s, pid_t pid, int cpu)
 
  */
 	ret = trace_seq_printf(s,
-		" ------------------------------------------\n");
-	ret += trace_seq_printf(s, " | %d)  %s-%d  =>  %s-%d\n",
-				  cpu, prev_comm, prev_pid, comm, pid);
-	ret += trace_seq_printf(s,
-		" ------------------------------------------\n\n");
+		"\n ------------------------------------------\n |");
+	if (!ret)
+		TRACE_TYPE_PARTIAL_LINE;
+
+	ret = print_graph_cpu(s, cpu);
+	if (ret == TRACE_TYPE_PARTIAL_LINE)
+		TRACE_TYPE_PARTIAL_LINE;
+
+	ret = print_graph_proc(s, prev_pid);
+	if (ret == TRACE_TYPE_PARTIAL_LINE)
+		TRACE_TYPE_PARTIAL_LINE;
+
+	ret = trace_seq_printf(s, " => ");
+	if (!ret)
+		TRACE_TYPE_PARTIAL_LINE;
+
+	ret = print_graph_proc(s, pid);
+	if (ret == TRACE_TYPE_PARTIAL_LINE)
+		TRACE_TYPE_PARTIAL_LINE;
+
+	ret = trace_seq_printf(s,
+		"\n ------------------------------------------\n\n");
+	if (!ret)
+		TRACE_TYPE_PARTIAL_LINE;
+
 	return ret;
 }
 
@@ -169,11 +232,50 @@ trace_branch_is_leaf(struct trace_iterator *iter,
 }
 
 
-static inline int
+static enum print_line_t
 print_graph_duration(unsigned long long duration, struct trace_seq *s)
 {
 	unsigned long nsecs_rem = do_div(duration, 1000);
-	return trace_seq_printf(s, "%4llu.%3lu us |  ", duration, nsecs_rem);
+	/* log10(ULONG_MAX) + '\0' */
+	char msecs_str[21];
+	char nsecs_str[5];
+	int ret, len;
+	int i;
+
+	sprintf(msecs_str, "%lu", (unsigned long) duration);
+
+	/* Print msecs */
+	ret = trace_seq_printf(s, msecs_str);
+	if (!ret)
+		return TRACE_TYPE_PARTIAL_LINE;
+
+	len = strlen(msecs_str);
+
+	/* Print nsecs (we don't want to exceed 7 numbers) */
+	if (len < 7) {
+		snprintf(nsecs_str, 8 - len, "%03lu", nsecs_rem);
+		ret = trace_seq_printf(s, ".%s", nsecs_str);
+		if (!ret)
+			return TRACE_TYPE_PARTIAL_LINE;
+		len += strlen(nsecs_str);
+	}
+
+	ret = trace_seq_printf(s, " us ");
+	if (!ret)
+		return TRACE_TYPE_PARTIAL_LINE;
+
+	/* Print remaining spaces to fit the row's width */
+	for (i = len; i < 7; i++) {
+		ret = trace_seq_printf(s, " ");
+		if (!ret)
+			return TRACE_TYPE_PARTIAL_LINE;
+	}
+
+	ret = trace_seq_printf(s, "|  ");
+	if (!ret)
+		return TRACE_TYPE_PARTIAL_LINE;
+	return TRACE_TYPE_HANDLED;
+
 }
 
 /* Signal a overhead of time execution to the output */
@@ -210,10 +312,6 @@ print_graph_entry_leaf(struct trace_iterator *iter,
 	call = &entry->graph_ent;
 	duration = graph_ret->rettime - graph_ret->calltime;
 
-	/* Must not exceed 8 characters: 9999.999 us */
-	if (duration > 10000000ULL)
-		duration = 9999999ULL;
-
 	/* Overhead */
 	if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERHEAD) {
 		ret = print_graph_overhead(duration, s);
@@ -223,7 +321,7 @@ print_graph_entry_leaf(struct trace_iterator *iter,
 
 	/* Duration */
 	ret = print_graph_duration(duration, s);
-	if (!ret)
+	if (ret == TRACE_TYPE_PARTIAL_LINE)
 		return TRACE_TYPE_PARTIAL_LINE;
 
 	/* Function */
@@ -288,12 +386,23 @@ print_graph_entry(struct ftrace_graph_ent_entry *field, struct trace_seq *s,
 	struct trace_entry *ent = iter->ent;
 
 	/* Pid */
-	if (!verif_pid(s, ent->pid, cpu))
+	if (verif_pid(s, ent->pid, cpu) == TRACE_TYPE_PARTIAL_LINE)
 		return TRACE_TYPE_PARTIAL_LINE;
 
 	/* Cpu */
 	if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU) {
 		ret = print_graph_cpu(s, cpu);
+		if (ret == TRACE_TYPE_PARTIAL_LINE)
+			return TRACE_TYPE_PARTIAL_LINE;
+	}
+
+	/* Proc */
+	if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC) {
+		ret = print_graph_proc(s, ent->pid);
+		if (ret == TRACE_TYPE_PARTIAL_LINE)
+			return TRACE_TYPE_PARTIAL_LINE;
+
+		ret = trace_seq_printf(s, " | ");
 		if (!ret)
 			return TRACE_TYPE_PARTIAL_LINE;
 	}
@@ -313,17 +422,24 @@ print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,
 	int ret;
 	unsigned long long duration = trace->rettime - trace->calltime;
 
-	/* Must not exceed 8 characters: xxxx.yyy us */
-	if (duration > 10000000ULL)
-		duration = 9999999ULL;
-
 	/* Pid */
-	if (!verif_pid(s, ent->pid, cpu))
+	if (verif_pid(s, ent->pid, cpu) == TRACE_TYPE_PARTIAL_LINE)
 		return TRACE_TYPE_PARTIAL_LINE;
 
 	/* Cpu */
 	if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU) {
 		ret = print_graph_cpu(s, cpu);
+		if (ret == TRACE_TYPE_PARTIAL_LINE)
+			return TRACE_TYPE_PARTIAL_LINE;
+	}
+
+	/* Proc */
+	if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC) {
+		ret = print_graph_proc(s, ent->pid);
+		if (ret == TRACE_TYPE_PARTIAL_LINE)
+			return TRACE_TYPE_PARTIAL_LINE;
+
+		ret = trace_seq_printf(s, " | ");
 		if (!ret)
 			return TRACE_TYPE_PARTIAL_LINE;
 	}
@@ -337,7 +453,7 @@ print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,
 
 	/* Duration */
 	ret = print_graph_duration(duration, s);
-	if (!ret)
+	if (ret == TRACE_TYPE_PARTIAL_LINE)
 		return TRACE_TYPE_PARTIAL_LINE;
 
 	/* Closing brace */

kernel/trace/trace_stack.c

@@ -48,7 +48,7 @@ static inline void check_stack(void)
 	if (!object_is_on_stack(&this_size))
 		return;
 
-	raw_local_irq_save(flags);
+	local_irq_save(flags);
 	__raw_spin_lock(&max_stack_lock);
 
 	/* a race could have already updated it */
@@ -78,6 +78,7 @@ static inline void check_stack(void)
 	 * on a new max, so it is far from a fast path.
 	 */
 	while (i < max_stack_trace.nr_entries) {
+		int found = 0;
 
 		stack_dump_index[i] = this_size;
 		p = start;
@@ -86,17 +87,19 @@ static inline void check_stack(void)
 			if (*p == stack_dump_trace[i]) {
 				this_size = stack_dump_index[i++] =
 					(top - p) * sizeof(unsigned long);
+				found = 1;
 				/* Start the search from here */
 				start = p + 1;
 			}
 		}
 
-		i++;
+		if (!found)
+			i++;
 	}
 
  out:
 	__raw_spin_unlock(&max_stack_lock);
-	raw_local_irq_restore(flags);
+	local_irq_restore(flags);
 }
 
 static void
@@ -162,11 +165,11 @@ stack_max_size_write(struct file *filp, const char __user *ubuf,
 	if (ret < 0)
 		return ret;
 
-	raw_local_irq_save(flags);
+	local_irq_save(flags);
 	__raw_spin_lock(&max_stack_lock);
 	*ptr = val;
 	__raw_spin_unlock(&max_stack_lock);
-	raw_local_irq_restore(flags);
+	local_irq_restore(flags);
 
 	return count;
 }