Merge branch 'linus' into x86/uv

11 files changed, 383 insertions, 611 deletions

diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 1cb3e1f616af..33dbefd471e8 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -1,13 +1,13 @@
 #
-# Architectures that offer an FTRACE implementation should select HAVE_FTRACE:
+# Architectures that offer an FUNCTION_TRACER implementation should
+#  select HAVE_FUNCTION_TRACER:
 #
 
 config NOP_TRACER
         bool
 
-config HAVE_FTRACE
+config HAVE_FUNCTION_TRACER
         bool
-        select NOP_TRACER
 
 config HAVE_DYNAMIC_FTRACE
         bool
@@ -25,12 +25,15 @@ config TRACING
         bool
         select DEBUG_FS
         select RING_BUFFER
-        select STACKTRACE
+        select STACKTRACE if STACKTRACE_SUPPORT
         select TRACEPOINTS
+        select NOP_TRACER
 
-config FTRACE
+menu "Tracers"
+
+config FUNCTION_TRACER
         bool "Kernel Function Tracer"
-        depends on HAVE_FTRACE
+        depends on HAVE_FUNCTION_TRACER
         depends on DEBUG_KERNEL
         select FRAME_POINTER
         select TRACING
@@ -49,7 +52,6 @@ config IRQSOFF_TRACER
         default n
         depends on TRACE_IRQFLAGS_SUPPORT
         depends on GENERIC_TIME
-        depends on HAVE_FTRACE
         depends on DEBUG_KERNEL
         select TRACE_IRQFLAGS
         select TRACING
@@ -73,7 +75,6 @@ config PREEMPT_TRACER
         default n
         depends on GENERIC_TIME
         depends on PREEMPT
-        depends on HAVE_FTRACE
         depends on DEBUG_KERNEL
         select TRACING
         select TRACER_MAX_TRACE
@@ -101,7 +102,6 @@ config SYSPROF_TRACER
 
 config SCHED_TRACER
         bool "Scheduling Latency Tracer"
-        depends on HAVE_FTRACE
         depends on DEBUG_KERNEL
         select TRACING
         select CONTEXT_SWITCH_TRACER
@@ -112,7 +112,6 @@ config SCHED_TRACER
 
 config CONTEXT_SWITCH_TRACER
         bool "Trace process context switches"
-        depends on HAVE_FTRACE
         depends on DEBUG_KERNEL
         select TRACING
         select MARKERS
@@ -122,9 +121,9 @@ config CONTEXT_SWITCH_TRACER
 
 config BOOT_TRACER
         bool "Trace boot initcalls"
-        depends on HAVE_FTRACE
         depends on DEBUG_KERNEL
         select TRACING
+        select CONTEXT_SWITCH_TRACER
         help
           This tracer helps developers to optimize boot times: it records
           the timings of the initcalls and traces key events and the identity
@@ -141,9 +140,9 @@ config BOOT_TRACER
 
 config STACK_TRACER
         bool "Trace max stack"
-        depends on HAVE_FTRACE
+        depends on HAVE_FUNCTION_TRACER
         depends on DEBUG_KERNEL
-        select FTRACE
+        select FUNCTION_TRACER
         select STACKTRACE
         help
           This special tracer records the maximum stack footprint of the
@@ -160,7 +159,7 @@ config STACK_TRACER
 
 config DYNAMIC_FTRACE
         bool "enable/disable ftrace tracepoints dynamically"
-        depends on FTRACE
+        depends on FUNCTION_TRACER
         depends on HAVE_DYNAMIC_FTRACE
         depends on DEBUG_KERNEL
         default y
@@ -170,7 +169,7 @@ config DYNAMIC_FTRACE
          with a No-Op instruction) as they are called. A table is
          created to dynamically enable them again.
 
-         This way a CONFIG_FTRACE kernel is slightly larger, but otherwise
+         This way a CONFIG_FUNCTION_TRACER kernel is slightly larger, but otherwise
          has native performance as long as no tracing is active.
 
          The changes to the code are done by a kernel thread that
@@ -195,3 +194,5 @@ config FTRACE_STARTUP_TEST
           a series of tests are made to verify that the tracer is
           functioning properly. It will do tests on all the configured
           tracers of ftrace.
+
+endmenu
diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile
index a85dfba88ba0..c8228b1a49e9 100644
--- a/kernel/trace/Makefile
+++ b/kernel/trace/Makefile
@@ -1,7 +1,7 @@
 
 # Do not instrument the tracer itself:
 
-ifdef CONFIG_FTRACE
+ifdef CONFIG_FUNCTION_TRACER
 ORIG_CFLAGS := $(KBUILD_CFLAGS)
 KBUILD_CFLAGS = $(subst -pg,,$(ORIG_CFLAGS))
 
@@ -10,13 +10,13 @@ CFLAGS_trace_selftest_dynamic.o = -pg
 obj-y += trace_selftest_dynamic.o
 endif
 
-obj-$(CONFIG_FTRACE) += libftrace.o
+obj-$(CONFIG_FUNCTION_TRACER) += libftrace.o
 obj-$(CONFIG_RING_BUFFER) += ring_buffer.o
 
 obj-$(CONFIG_TRACING) += trace.o
 obj-$(CONFIG_CONTEXT_SWITCH_TRACER) += trace_sched_switch.o
 obj-$(CONFIG_SYSPROF_TRACER) += trace_sysprof.o
-obj-$(CONFIG_FTRACE) += trace_functions.o
+obj-$(CONFIG_FUNCTION_TRACER) += trace_functions.o
 obj-$(CONFIG_IRQSOFF_TRACER) += trace_irqsoff.o
 obj-$(CONFIG_PREEMPT_TRACER) += trace_irqsoff.o
 obj-$(CONFIG_SCHED_TRACER) += trace_sched_wakeup.o
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 4dda4f60a2a9..e60205722d0c 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -25,13 +25,24 @@
 #include <linux/ftrace.h>
 #include <linux/sysctl.h>
 #include <linux/ctype.h>
-#include <linux/hash.h>
 #include <linux/list.h>
 
 #include <asm/ftrace.h>
 
 #include "trace.h"
 
+#define FTRACE_WARN_ON(cond)                    \
+        do {                                    \
+                if (WARN_ON(cond))              \
+                        ftrace_kill();          \
+        } while (0)
+
+#define FTRACE_WARN_ON_ONCE(cond)               \
+        do {                                    \
+                if (WARN_ON_ONCE(cond))         \
+                        ftrace_kill();          \
+        } while (0)
+
 /* ftrace_enabled is a method to turn ftrace on or off */
 int ftrace_enabled __read_mostly;
 static int last_ftrace_enabled;
@@ -153,21 +164,8 @@ static int __unregister_ftrace_function(struct ftrace_ops *ops)
 }
 
 #ifdef CONFIG_DYNAMIC_FTRACE
-
 #ifndef CONFIG_FTRACE_MCOUNT_RECORD
-/*
- * The hash lock is only needed when the recording of the mcount
- * callers are dynamic. That is, by the caller themselves and
- * not recorded via the compilation.
- */
-static DEFINE_SPINLOCK(ftrace_hash_lock);
-#define ftrace_hash_lock(flags)   spin_lock_irqsave(&ftrace_hash_lock, flags)
-#define ftrace_hash_unlock(flags) \
-                        spin_unlock_irqrestore(&ftrace_hash_lock, flags)
-#else
-/* This is protected via the ftrace_lock with MCOUNT_RECORD. */
-#define ftrace_hash_lock(flags)   do { (void)(flags); } while (0)
-#define ftrace_hash_unlock(flags) do { } while(0)
+# error Dynamic ftrace depends on MCOUNT_RECORD
 #endif
 
 /*
@@ -178,8 +176,6 @@ static DEFINE_SPINLOCK(ftrace_hash_lock);
  */
 static unsigned long mcount_addr = MCOUNT_ADDR;
 
-static struct task_struct *ftraced_task;
-
 enum {
         FTRACE_ENABLE_CALLS             = (1 << 0),
         FTRACE_DISABLE_CALLS            = (1 << 1),
@@ -189,14 +185,9 @@ enum {
 };
 
 static int ftrace_filtered;
-static int tracing_on;
-static int frozen_record_count;
 
-static struct hlist_head ftrace_hash[FTRACE_HASHSIZE];
+static LIST_HEAD(ftrace_new_addrs);
 
-static DEFINE_PER_CPU(int, ftrace_shutdown_disable_cpu);
-
-static DEFINE_MUTEX(ftraced_lock);
 static DEFINE_MUTEX(ftrace_regex_lock);
 
 struct ftrace_page {
@@ -214,16 +205,13 @@ struct ftrace_page {
 static struct ftrace_page       *ftrace_pages_start;
 static struct ftrace_page       *ftrace_pages;
 
-static int ftraced_trigger;
-static int ftraced_suspend;
-static int ftraced_stop;
-
-static int ftrace_record_suspend;
-
 static struct dyn_ftrace *ftrace_free_records;
 
 
 #ifdef CONFIG_KPROBES
+
+static int frozen_record_count;
+
 static inline void freeze_record(struct dyn_ftrace *rec)
 {
         if (!(rec->flags & FTRACE_FL_FROZEN)) {
@@ -250,72 +238,6 @@ static inline int record_frozen(struct dyn_ftrace *rec)
 # define record_frozen(rec)                     ({ 0; })
 #endif /* CONFIG_KPROBES */
 
-int skip_trace(unsigned long ip)
-{
-        unsigned long fl;
-        struct dyn_ftrace *rec;
-        struct hlist_node *t;
-        struct hlist_head *head;
-
-        if (frozen_record_count == 0)
-                return 0;
-
-        head = &ftrace_hash[hash_long(ip, FTRACE_HASHBITS)];
-        hlist_for_each_entry_rcu(rec, t, head, node) {
-                if (rec->ip == ip) {
-                        if (record_frozen(rec)) {
-                                if (rec->flags & FTRACE_FL_FAILED)
-                                        return 1;
-
-                                if (!(rec->flags & FTRACE_FL_CONVERTED))
-                                        return 1;
-
-                                if (!tracing_on || !ftrace_enabled)
-                                        return 1;
-
-                                if (ftrace_filtered) {
-                                        fl = rec->flags & (FTRACE_FL_FILTER |
-                                                           FTRACE_FL_NOTRACE);
-                                        if (!fl || (fl & FTRACE_FL_NOTRACE))
-                                                return 1;
-                                }
-                        }
-                        break;
-                }
-        }
-
-        return 0;
-}
-
-static inline int
-ftrace_ip_in_hash(unsigned long ip, unsigned long key)
-{
-        struct dyn_ftrace *p;
-        struct hlist_node *t;
-        int found = 0;
-
-        hlist_for_each_entry_rcu(p, t, &ftrace_hash[key], node) {
-                if (p->ip == ip) {
-                        found = 1;
-                        break;
-                }
-        }
-
-        return found;
-}
-
-static inline void
-ftrace_add_hash(struct dyn_ftrace *node, unsigned long key)
-{
-        hlist_add_head_rcu(&node->node, &ftrace_hash[key]);
-}
-
-/* called from kstop_machine */
-static inline void ftrace_del_hash(struct dyn_ftrace *node)
-{
-        hlist_del(&node->node);
-}
-
 static void ftrace_free_rec(struct dyn_ftrace *rec)
 {
         rec->ip = (unsigned long)ftrace_free_records;
@@ -346,7 +268,6 @@ void ftrace_release(void *start, unsigned long size)
                 }
         }
         spin_unlock(&ftrace_lock);
-
 }
 
 static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip)
@@ -358,10 +279,8 @@ static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip)
                 rec = ftrace_free_records;
 
                 if (unlikely(!(rec->flags & FTRACE_FL_FREE))) {
-                        WARN_ON_ONCE(1);
+                        FTRACE_WARN_ON_ONCE(1);
                         ftrace_free_records = NULL;
-                        ftrace_disabled = 1;
-                        ftrace_enabled = 0;
                         return NULL;
                 }
 
@@ -371,76 +290,36 @@ static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip)
         }
 
         if (ftrace_pages->index == ENTRIES_PER_PAGE) {
-                if (!ftrace_pages->next)
-                        return NULL;
+                if (!ftrace_pages->next) {
+                        /* allocate another page */
+                        ftrace_pages->next =
+                                (void *)get_zeroed_page(GFP_KERNEL);
+                        if (!ftrace_pages->next)
+                                return NULL;
+                }
                 ftrace_pages = ftrace_pages->next;
         }
 
         return &ftrace_pages->records[ftrace_pages->index++];
 }
 
-static void
+static struct dyn_ftrace *
 ftrace_record_ip(unsigned long ip)
 {
-        struct dyn_ftrace *node;
-        unsigned long flags;
-        unsigned long key;
-        int resched;
-        int cpu;
+        struct dyn_ftrace *rec;
 
         if (!ftrace_enabled || ftrace_disabled)
-                return;
-
-        resched = need_resched();
-        preempt_disable_notrace();
+                return NULL;
 
-        /*
-         * We simply need to protect against recursion.
-         * Use the the raw version of smp_processor_id and not
-         * __get_cpu_var which can call debug hooks that can
-         * cause a recursive crash here.
-         */
-        cpu = raw_smp_processor_id();
-        per_cpu(ftrace_shutdown_disable_cpu, cpu)++;
-        if (per_cpu(ftrace_shutdown_disable_cpu, cpu) != 1)
-                goto out;
-
-        if (unlikely(ftrace_record_suspend))
-                goto out;
-
-        key = hash_long(ip, FTRACE_HASHBITS);
-
-        WARN_ON_ONCE(key >= FTRACE_HASHSIZE);
-
-        if (ftrace_ip_in_hash(ip, key))
-                goto out;
-
-        ftrace_hash_lock(flags);
-
-        /* This ip may have hit the hash before the lock */
-        if (ftrace_ip_in_hash(ip, key))
-                goto out_unlock;
-
-        node = ftrace_alloc_dyn_node(ip);
-        if (!node)
-                goto out_unlock;
-
-        node->ip = ip;
-
-        ftrace_add_hash(node, key);
+        rec = ftrace_alloc_dyn_node(ip);
+        if (!rec)
+                return NULL;
 
-        ftraced_trigger = 1;
+        rec->ip = ip;
 
- out_unlock:
-        ftrace_hash_unlock(flags);
- out:
-        per_cpu(ftrace_shutdown_disable_cpu, cpu)--;
+        list_add(&rec->list, &ftrace_new_addrs);
 
-        /* prevent recursion with scheduler */
-        if (resched)
-                preempt_enable_no_resched_notrace();
-        else
-                preempt_enable_notrace();
+        return rec;
 }
 
 #define FTRACE_ADDR ((long)(ftrace_caller))
@@ -559,7 +438,6 @@ static void ftrace_replace_code(int enable)
                                 rec->flags |= FTRACE_FL_FAILED;
                                 if ((system_state == SYSTEM_BOOTING) ||
                                     !core_kernel_text(rec->ip)) {
-                                        ftrace_del_hash(rec);
                                         ftrace_free_rec(rec);
                                 }
                         }
@@ -567,15 +445,6 @@ static void ftrace_replace_code(int enable)
         }
 }
 
-static void ftrace_shutdown_replenish(void)
-{
-        if (ftrace_pages->next)
-                return;
-
-        /* allocate another page */
-        ftrace_pages->next = (void *)get_zeroed_page(GFP_KERNEL);
-}
-
 static void print_ip_ins(const char *fmt, unsigned char *p)
 {
         int i;
@@ -591,23 +460,23 @@ ftrace_code_disable(struct dyn_ftrace *rec)
 {
         unsigned long ip;
         unsigned char *nop, *call;
-        int failed;
+        int ret;
 
         ip = rec->ip;
 
         nop = ftrace_nop_replace();
         call = ftrace_call_replace(ip, mcount_addr);
 
-        failed = ftrace_modify_code(ip, call, nop);
-        if (failed) {
-                switch (failed) {
-                case 1:
-                        WARN_ON_ONCE(1);
+        ret = ftrace_modify_code(ip, call, nop);
+        if (ret) {
+                switch (ret) {
+                case -EFAULT:
+                        FTRACE_WARN_ON_ONCE(1);
                         pr_info("ftrace faulted on modifying ");
                         print_ip_sym(ip);
                         break;
-                case 2:
-                        WARN_ON_ONCE(1);
+                case -EINVAL:
+                        FTRACE_WARN_ON_ONCE(1);
                         pr_info("ftrace failed to modify ");
                         print_ip_sym(ip);
                         print_ip_ins(" expected: ", call);
@@ -615,6 +484,15 @@ ftrace_code_disable(struct dyn_ftrace *rec)
                         print_ip_ins(" replace: ", nop);
                         printk(KERN_CONT "\n");
                         break;
+                case -EPERM:
+                        FTRACE_WARN_ON_ONCE(1);
+                        pr_info("ftrace faulted on writing ");
+                        print_ip_sym(ip);
+                        break;
+                default:
+                        FTRACE_WARN_ON_ONCE(1);
+                        pr_info("ftrace faulted on unknown error ");
+                        print_ip_sym(ip);
                 }
 
                 rec->flags |= FTRACE_FL_FAILED;
@@ -623,37 +501,18 @@ ftrace_code_disable(struct dyn_ftrace *rec)
         return 1;
 }
 
-static int __ftrace_update_code(void *ignore);
-
 static int __ftrace_modify_code(void *data)
 {
-        unsigned long addr;
         int *command = data;
 
-        if (*command & FTRACE_ENABLE_CALLS) {
-                /*
-                 * Update any recorded ips now that we have the
-                 * machine stopped
-                 */
-                __ftrace_update_code(NULL);
+        if (*command & FTRACE_ENABLE_CALLS)
                 ftrace_replace_code(1);
-                tracing_on = 1;
-        } else if (*command & FTRACE_DISABLE_CALLS) {
+        else if (*command & FTRACE_DISABLE_CALLS)
                 ftrace_replace_code(0);
-                tracing_on = 0;
-        }
 
         if (*command & FTRACE_UPDATE_TRACE_FUNC)
                 ftrace_update_ftrace_func(ftrace_trace_function);
 
-        if (*command & FTRACE_ENABLE_MCOUNT) {
-                addr = (unsigned long)ftrace_record_ip;
-                ftrace_mcount_set(&addr);
-        } else if (*command & FTRACE_DISABLE_MCOUNT) {
-                addr = (unsigned long)ftrace_stub;
-                ftrace_mcount_set(&addr);
-        }
-
         return 0;
 }
 
@@ -662,26 +521,9 @@ static void ftrace_run_update_code(int command)
         stop_machine(__ftrace_modify_code, &command, NULL);
 }
 
-void ftrace_disable_daemon(void)
-{
-        /* Stop the daemon from calling kstop_machine */
-        mutex_lock(&ftraced_lock);
-        ftraced_stop = 1;
-        mutex_unlock(&ftraced_lock);
-
-        ftrace_force_update();
-}
-
-void ftrace_enable_daemon(void)
-{
-        mutex_lock(&ftraced_lock);
-        ftraced_stop = 0;
-        mutex_unlock(&ftraced_lock);
-
-        ftrace_force_update();
-}
-
 static ftrace_func_t saved_ftrace_func;
+static int ftrace_start;
+static DEFINE_MUTEX(ftrace_start_lock);
 
 static void ftrace_startup(void)
 {
@@ -690,9 +532,9 @@ static void ftrace_startup(void)
         if (unlikely(ftrace_disabled))
                 return;
 
-        mutex_lock(&ftraced_lock);
-        ftraced_suspend++;
-        if (ftraced_suspend == 1)
+        mutex_lock(&ftrace_start_lock);
+        ftrace_start++;
+        if (ftrace_start == 1)
                 command |= FTRACE_ENABLE_CALLS;
 
         if (saved_ftrace_func != ftrace_trace_function) {
@@ -705,7 +547,7 @@ static void ftrace_startup(void)
 
         ftrace_run_update_code(command);
  out:
-        mutex_unlock(&ftraced_lock);
+        mutex_unlock(&ftrace_start_lock);
 }
 
 static void ftrace_shutdown(void)
@@ -715,9 +557,9 @@ static void ftrace_shutdown(void)
         if (unlikely(ftrace_disabled))
                 return;
 
-        mutex_lock(&ftraced_lock);
-        ftraced_suspend--;
-        if (!ftraced_suspend)
+        mutex_lock(&ftrace_start_lock);
+        ftrace_start--;
+        if (!ftrace_start)
                 command |= FTRACE_DISABLE_CALLS;
 
         if (saved_ftrace_func != ftrace_trace_function) {
@@ -730,7 +572,7 @@ static void ftrace_shutdown(void)
 
         ftrace_run_update_code(command);
  out:
-        mutex_unlock(&ftraced_lock);
+        mutex_unlock(&ftrace_start_lock);
 }
 
 static void ftrace_startup_sysctl(void)
@@ -740,15 +582,15 @@ static void ftrace_startup_sysctl(void)
         if (unlikely(ftrace_disabled))
                 return;
 
-        mutex_lock(&ftraced_lock);
+        mutex_lock(&ftrace_start_lock);
         /* Force update next time */
         saved_ftrace_func = NULL;
-        /* ftraced_suspend is true if we want ftrace running */
-        if (ftraced_suspend)
+        /* ftrace_start is true if we want ftrace running */
+        if (ftrace_start)
                 command |= FTRACE_ENABLE_CALLS;
 
         ftrace_run_update_code(command);
-        mutex_unlock(&ftraced_lock);
+        mutex_unlock(&ftrace_start_lock);
 }
 
 static void ftrace_shutdown_sysctl(void)
@@ -758,112 +600,50 @@ static void ftrace_shutdown_sysctl(void)
         if (unlikely(ftrace_disabled))
                 return;
 
-        mutex_lock(&ftraced_lock);
-        /* ftraced_suspend is true if ftrace is running */
-        if (ftraced_suspend)
+        mutex_lock(&ftrace_start_lock);
+        /* ftrace_start is true if ftrace is running */
+        if (ftrace_start)
                 command |= FTRACE_DISABLE_CALLS;
 
         ftrace_run_update_code(command);
-        mutex_unlock(&ftraced_lock);
+        mutex_unlock(&ftrace_start_lock);
 }
 
 static cycle_t          ftrace_update_time;
 static unsigned long    ftrace_update_cnt;
 unsigned long           ftrace_update_tot_cnt;
 
-static int __ftrace_update_code(void *ignore)
+static int ftrace_update_code(void)
 {
-        int i, save_ftrace_enabled;
+        struct dyn_ftrace *p, *t;
         cycle_t start, stop;
-        struct dyn_ftrace *p;
-        struct hlist_node *t, *n;
-        struct hlist_head *head, temp_list;
-
-        /* Don't be recording funcs now */
-        ftrace_record_suspend++;
-        save_ftrace_enabled = ftrace_enabled;
-        ftrace_enabled = 0;
 
         start = ftrace_now(raw_smp_processor_id());
         ftrace_update_cnt = 0;
 
-        /* No locks needed, the machine is stopped! */
-        for (i = 0; i < FTRACE_HASHSIZE; i++) {
-                INIT_HLIST_HEAD(&temp_list);
-                head = &ftrace_hash[i];
-
-                /* all CPUS are stopped, we are safe to modify code */
-                hlist_for_each_entry_safe(p, t, n, head, node) {
-                        /* Skip over failed records which have not been
-                         * freed. */
-                        if (p->flags & FTRACE_FL_FAILED)
-                                continue;
-
-                        /* Unconverted records are always at the head of the
-                         * hash bucket. Once we encounter a converted record,
-                         * simply skip over to the next bucket. Saves ftraced
-                         * some processor cycles (ftrace does its bid for
-                         * global warming :-p ). */
-                        if (p->flags & (FTRACE_FL_CONVERTED))
-                                break;
+        list_for_each_entry_safe(p, t, &ftrace_new_addrs, list) {
 
-                        /* Ignore updates to this record's mcount site.
-                         * Reintroduce this record at the head of this
-                         * bucket to attempt to "convert" it again if
-                         * the kprobe on it is unregistered before the
-                         * next run. */
-                        if (get_kprobe((void *)p->ip)) {
-                                ftrace_del_hash(p);
-                                INIT_HLIST_NODE(&p->node);
-                                hlist_add_head(&p->node, &temp_list);
-                                freeze_record(p);
-                                continue;
-                        } else {
-                                unfreeze_record(p);
-                        }
+                /* If something went wrong, bail without enabling anything */
+                if (unlikely(ftrace_disabled))
+                        return -1;
 
-                        /* convert record (i.e, patch mcount-call with NOP) */
-                        if (ftrace_code_disable(p)) {
-                                p->flags |= FTRACE_FL_CONVERTED;
-                                ftrace_update_cnt++;
-                        } else {
-                                if ((system_state == SYSTEM_BOOTING) ||
-                                    !core_kernel_text(p->ip)) {
-                                        ftrace_del_hash(p);
-                                        ftrace_free_rec(p);
-                                }
-                        }
-                }
+                list_del_init(&p->list);
 
-                hlist_for_each_entry_safe(p, t, n, &temp_list, node) {
-                        hlist_del(&p->node);
-                        INIT_HLIST_NODE(&p->node);
-                        hlist_add_head(&p->node, head);
-                }
+                /* convert record (i.e, patch mcount-call with NOP) */
+                if (ftrace_code_disable(p)) {
+                        p->flags |= FTRACE_FL_CONVERTED;
+                        ftrace_update_cnt++;
+                } else
+                        ftrace_free_rec(p);
         }
 
         stop = ftrace_now(raw_smp_processor_id());
         ftrace_update_time = stop - start;
         ftrace_update_tot_cnt += ftrace_update_cnt;
-        ftraced_trigger = 0;
-
-        ftrace_enabled = save_ftrace_enabled;
-        ftrace_record_suspend--;
 
         return 0;
 }
 
-static int ftrace_update_code(void)
-{
-        if (unlikely(ftrace_disabled) ||
-            !ftrace_enabled || !ftraced_trigger)
-                return 0;
-
-        stop_machine(__ftrace_update_code, NULL, NULL);
-
-        return 1;
-}
-
 static int __init ftrace_dyn_table_alloc(unsigned long num_to_init)
 {
         struct ftrace_page *pg;
@@ -892,8 +672,8 @@ static int __init ftrace_dyn_table_alloc(unsigned long num_to_init)
         pg = ftrace_pages = ftrace_pages_start;
 
         cnt = num_to_init / ENTRIES_PER_PAGE;
-        pr_info("ftrace: allocating %ld hash entries in %d pages\n",
-                num_to_init, cnt);
+        pr_info("ftrace: allocating %ld entries in %d pages\n",
+                num_to_init, cnt + 1);
 
         for (i = 0; i < cnt; i++) {
                 pg->next = (void *)get_zeroed_page(GFP_KERNEL);
@@ -973,13 +753,11 @@ static void *t_start(struct seq_file *m, loff_t *pos)
         void *p = NULL;
         loff_t l = -1;
 
-        if (*pos != iter->pos) {
-                for (p = t_next(m, p, &l); p && l < *pos; p = t_next(m, p, &l))
-                        ;
-        } else {
-                l = *pos;
-                p = t_next(m, p, &l);
-        }
+        if (*pos > iter->pos)
+                *pos = iter->pos;
+
+        l = *pos;
+        p = t_next(m, p, &l);
 
         return p;
 }
@@ -990,15 +768,21 @@ static void t_stop(struct seq_file *m, void *p)
 
 static int t_show(struct seq_file *m, void *v)
 {
+        struct ftrace_iterator *iter = m->private;
         struct dyn_ftrace *rec = v;
         char str[KSYM_SYMBOL_LEN];
+        int ret = 0;
 
         if (!rec)
                 return 0;
 
         kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
 
-        seq_printf(m, "%s\n", str);
+        ret = seq_printf(m, "%s\n", str);
+        if (ret < 0) {
+                iter->pos--;
+                iter->idx--;
+        }
 
         return 0;
 }
@@ -1024,7 +808,7 @@ ftrace_avail_open(struct inode *inode, struct file *file)
                 return -ENOMEM;
 
         iter->pg = ftrace_pages_start;
-        iter->pos = -1;
+        iter->pos = 0;
 
         ret = seq_open(file, &show_ftrace_seq_ops);
         if (!ret) {
@@ -1111,7 +895,7 @@ ftrace_regex_open(struct inode *inode, struct file *file, int enable)
 
         if (file->f_mode & FMODE_READ) {
                 iter->pg = ftrace_pages_start;
-                iter->pos = -1;
+                iter->pos = 0;
                 iter->flags = enable ? FTRACE_ITER_FILTER :
                         FTRACE_ITER_NOTRACE;
 
@@ -1401,10 +1185,10 @@ ftrace_regex_release(struct inode *inode, struct file *file, int enable)
         }
 
         mutex_lock(&ftrace_sysctl_lock);
-        mutex_lock(&ftraced_lock);
-        if (iter->filtered && ftraced_suspend && ftrace_enabled)
+        mutex_lock(&ftrace_start_lock);
+        if (iter->filtered && ftrace_start && ftrace_enabled)
                 ftrace_run_update_code(FTRACE_ENABLE_CALLS);
-        mutex_unlock(&ftraced_lock);
+        mutex_unlock(&ftrace_start_lock);
         mutex_unlock(&ftrace_sysctl_lock);
 
         kfree(iter);
@@ -1424,55 +1208,6 @@ ftrace_notrace_release(struct inode *inode, struct file *file)
         return ftrace_regex_release(inode, file, 0);
 }
 
-static ssize_t
-ftraced_read(struct file *filp, char __user *ubuf,
-                     size_t cnt, loff_t *ppos)
-{
-        /* don't worry about races */
-        char *buf = ftraced_stop ? "disabled\n" : "enabled\n";
-        int r = strlen(buf);
-
-        return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
-}
-
-static ssize_t
-ftraced_write(struct file *filp, const char __user *ubuf,
-                      size_t cnt, loff_t *ppos)
-{
-        char buf[64];
-        long val;
-        int ret;
-
-        if (cnt >= sizeof(buf))
-                return -EINVAL;
-
-        if (copy_from_user(&buf, ubuf, cnt))
-                return -EFAULT;
-
-        if (strncmp(buf, "enable", 6) == 0)
-                val = 1;
-        else if (strncmp(buf, "disable", 7) == 0)
-                val = 0;
-        else {
-                buf[cnt] = 0;
-
-                ret = strict_strtoul(buf, 10, &val);
-                if (ret < 0)
-                        return ret;
-
-                val = !!val;
-        }
-
-        if (val)
-                ftrace_enable_daemon();
-        else
-                ftrace_disable_daemon();
-
-        filp->f_pos += cnt;
-
-        return cnt;
-}
-
 static struct file_operations ftrace_avail_fops = {
         .open = ftrace_avail_open,
         .read = seq_read,
@@ -1503,54 +1238,6 @@ static struct file_operations ftrace_notrace_fops = {
         .release = ftrace_notrace_release,
 };
 
-static struct file_operations ftraced_fops = {
-        .open = tracing_open_generic,
-        .read = ftraced_read,
-        .write = ftraced_write,
-};
-
-/**
- * ftrace_force_update - force an update to all recording ftrace functions
- */
-int ftrace_force_update(void)
-{
-        int ret = 0;
-
-        if (unlikely(ftrace_disabled))
-                return -ENODEV;
-
-        mutex_lock(&ftrace_sysctl_lock);
-        mutex_lock(&ftraced_lock);
-
-        /*
-         * If ftraced_trigger is not set, then there is nothing
-         * to update.
-         */
-        if (ftraced_trigger && !ftrace_update_code())
-                ret = -EBUSY;
-
-        mutex_unlock(&ftraced_lock);
-        mutex_unlock(&ftrace_sysctl_lock);
-
-        return ret;
-}
-
-static void ftrace_force_shutdown(void)
-{
-        struct task_struct *task;
-        int command = FTRACE_DISABLE_CALLS | FTRACE_UPDATE_TRACE_FUNC;
-
-        mutex_lock(&ftraced_lock);
-        task = ftraced_task;
-        ftraced_task = NULL;
-        ftraced_suspend = -1;
-        ftrace_run_update_code(command);
-        mutex_unlock(&ftraced_lock);
-
-        if (task)
-                kthread_stop(task);
-}
-
 static __init int ftrace_init_debugfs(void)
 {
         struct dentry *d_tracer;
@@ -1581,17 +1268,11 @@ static __init int ftrace_init_debugfs(void)
                 pr_warning("Could not create debugfs "
                            "'set_ftrace_notrace' entry\n");
 
-        entry = debugfs_create_file("ftraced_enabled", 0644, d_tracer,
-                                    NULL, &ftraced_fops);
-        if (!entry)
-                pr_warning("Could not create debugfs "
-                           "'ftraced_enabled' entry\n");
         return 0;
 }
 
 fs_initcall(ftrace_init_debugfs);
 
-#ifdef CONFIG_FTRACE_MCOUNT_RECORD
 static int ftrace_convert_nops(unsigned long *start,
                                unsigned long *end)
 {
@@ -1599,20 +1280,18 @@ static int ftrace_convert_nops(unsigned long *start,
         unsigned long addr;
         unsigned long flags;
 
+        mutex_lock(&ftrace_start_lock);
         p = start;
         while (p < end) {
                 addr = ftrace_call_adjust(*p++);
-                /* should not be called from interrupt context */
-                spin_lock(&ftrace_lock);
                 ftrace_record_ip(addr);
-                spin_unlock(&ftrace_lock);
-                ftrace_shutdown_replenish();
         }
 
-        /* p is ignored */
+        /* disable interrupts to prevent kstop machine */
         local_irq_save(flags);
-        __ftrace_update_code(p);
+        ftrace_update_code();
         local_irq_restore(flags);
+        mutex_unlock(&ftrace_start_lock);
 
         return 0;
 }
@@ -1658,130 +1337,34 @@ void __init ftrace_init(void)
  failed:
         ftrace_disabled = 1;
 }
-#else /* CONFIG_FTRACE_MCOUNT_RECORD */
-static int ftraced(void *ignore)
-{
-        unsigned long usecs;
-
-        while (!kthread_should_stop()) {
-
-                set_current_state(TASK_INTERRUPTIBLE);
 
-                /* check once a second */
-                schedule_timeout(HZ);
-
-                if (unlikely(ftrace_disabled))
-                        continue;
-
-                mutex_lock(&ftrace_sysctl_lock);
-                mutex_lock(&ftraced_lock);
-                if (!ftraced_suspend && !ftraced_stop &&
-                    ftrace_update_code()) {
-                        usecs = nsecs_to_usecs(ftrace_update_time);
-                        if (ftrace_update_tot_cnt > 100000) {
-                                ftrace_update_tot_cnt = 0;
-                                pr_info("hm, dftrace overflow: %lu change%s"
-                                        " (%lu total) in %lu usec%s\n",
-                                        ftrace_update_cnt,
-                                        ftrace_update_cnt != 1 ? "s" : "",
-                                        ftrace_update_tot_cnt,
-                                        usecs, usecs != 1 ? "s" : "");
-                                ftrace_disabled = 1;
-                                WARN_ON_ONCE(1);
-                        }
-                }
-                mutex_unlock(&ftraced_lock);
-                mutex_unlock(&ftrace_sysctl_lock);
-
-                ftrace_shutdown_replenish();
-        }
-        __set_current_state(TASK_RUNNING);
-        return 0;
-}
+#else
 
-static int __init ftrace_dynamic_init(void)
+static int __init ftrace_nodyn_init(void)
 {
-        struct task_struct *p;
-        unsigned long addr;
-        int ret;
-
-        addr = (unsigned long)ftrace_record_ip;
-
-        stop_machine(ftrace_dyn_arch_init, &addr, NULL);
-
-        /* ftrace_dyn_arch_init places the return code in addr */
-        if (addr) {
-                ret = (int)addr;
-                goto failed;
-        }
-
-        ret = ftrace_dyn_table_alloc(NR_TO_INIT);
-        if (ret)
-                goto failed;
-
-        p = kthread_run(ftraced, NULL, "ftraced");
-        if (IS_ERR(p)) {
-                ret = -1;
-                goto failed;
-        }
-
-        last_ftrace_enabled = ftrace_enabled = 1;
-        ftraced_task = p;
-
+        ftrace_enabled = 1;
         return 0;
-
- failed:
-        ftrace_disabled = 1;
-        return ret;
 }
+device_initcall(ftrace_nodyn_init);
 
-core_initcall(ftrace_dynamic_init);
-#endif /* CONFIG_FTRACE_MCOUNT_RECORD */
-
-#else
 # define ftrace_startup()               do { } while (0)
 # define ftrace_shutdown()              do { } while (0)
 # define ftrace_startup_sysctl()        do { } while (0)
 # define ftrace_shutdown_sysctl()       do { } while (0)
-# define ftrace_force_shutdown()        do { } while (0)
 #endif /* CONFIG_DYNAMIC_FTRACE */
 
 /**
- * ftrace_kill_atomic - kill ftrace from critical sections
+ * ftrace_kill - kill ftrace
  *
  * This function should be used by panic code. It stops ftrace
  * but in a not so nice way. If you need to simply kill ftrace
  * from a non-atomic section, use ftrace_kill.
  */
-void ftrace_kill_atomic(void)
-{
-        ftrace_disabled = 1;
-        ftrace_enabled = 0;
-#ifdef CONFIG_DYNAMIC_FTRACE
-        ftraced_suspend = -1;
-#endif
-        clear_ftrace_function();
-}
-
-/**
- * ftrace_kill - totally shutdown ftrace
- *
- * This is a safety measure. If something was detected that seems
- * wrong, calling this function will keep ftrace from doing
- * any more modifications, and updates.
- * used when something went wrong.
- */
 void ftrace_kill(void)
 {
-        mutex_lock(&ftrace_sysctl_lock);
         ftrace_disabled = 1;
         ftrace_enabled = 0;
-
         clear_ftrace_function();
-        mutex_unlock(&ftrace_sysctl_lock);
-
-        /* Try to totally disable ftrace */
-        ftrace_force_shutdown();
 }
 
 /**
@@ -1870,3 +1453,4 @@ ftrace_enable_sysctl(struct ctl_table *table, int write,
         mutex_unlock(&ftrace_sysctl_lock);
         return ret;
 }
+
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 94af1fe56bb4..036456cbb4f7 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -16,14 +16,49 @@
 #include <linux/list.h>
 #include <linux/fs.h>
 
+#include "trace.h"
+
+/* Global flag to disable all recording to ring buffers */
+static int ring_buffers_off __read_mostly;
+
+/**
+ * tracing_on - enable all tracing buffers
+ *
+ * This function enables all tracing buffers that may have been
+ * disabled with tracing_off.
+ */
+void tracing_on(void)
+{
+        ring_buffers_off = 0;
+}
+
+/**
+ * tracing_off - turn off all tracing buffers
+ *
+ * This function stops all tracing buffers from recording data.
+ * It does not disable any overhead the tracers themselves may
+ * be causing. This function simply causes all recording to
+ * the ring buffers to fail.
+ */
+void tracing_off(void)
+{
+        ring_buffers_off = 1;
+}
+
 /* Up this if you want to test the TIME_EXTENTS and normalization */
 #define DEBUG_SHIFT 0
 
 /* FIXME!!! */
 u64 ring_buffer_time_stamp(int cpu)
 {
+        u64 time;
+
+        preempt_disable_notrace();
         /* shift to debug/test normalization and TIME_EXTENTS */
-        return sched_clock() << DEBUG_SHIFT;
+        time = sched_clock() << DEBUG_SHIFT;
+        preempt_enable_notrace();
+
+        return time;
 }
 
 void ring_buffer_normalize_time_stamp(int cpu, u64 *ts)
@@ -130,7 +165,7 @@ struct buffer_page {
 static inline void free_buffer_page(struct buffer_page *bpage)
 {
         if (bpage->page)
-                __free_page(bpage->page);
+                free_page((unsigned long)bpage->page);
         kfree(bpage);
 }
 
@@ -503,6 +538,12 @@ int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size)
         LIST_HEAD(pages);
         int i, cpu;
 
+        /*
+         * Always succeed at resizing a non-existent buffer:
+         */
+        if (!buffer)
+                return size;
+
         size = DIV_ROUND_UP(size, BUF_PAGE_SIZE);
         size *= BUF_PAGE_SIZE;
         buffer_size = buffer->pages * BUF_PAGE_SIZE;
@@ -966,7 +1007,9 @@ rb_add_time_stamp(struct ring_buffer_per_cpu *cpu_buffer,
         if (unlikely(*delta > (1ULL << 59) && !once++)) {
                 printk(KERN_WARNING "Delta way too big! %llu"
                        " ts=%llu write stamp = %llu\n",
-                       *delta, *ts, cpu_buffer->write_stamp);
+                       (unsigned long long)*delta,
+                       (unsigned long long)*ts,
+                       (unsigned long long)cpu_buffer->write_stamp);
                 WARN_ON(1);
         }
 
@@ -1020,8 +1063,23 @@ rb_reserve_next_event(struct ring_buffer_per_cpu *cpu_buffer,
         struct ring_buffer_event *event;
         u64 ts, delta;
         int commit = 0;
+        int nr_loops = 0;
 
  again:
+        /*
+         * We allow for interrupts to reenter here and do a trace.
+         * If one does, it will cause this original code to loop
+         * back here. Even with heavy interrupts happening, this
+         * should only happen a few times in a row. If this happens
+         * 1000 times in a row, there must be either an interrupt
+         * storm or we have something buggy.
+         * Bail!
+         */
+        if (unlikely(++nr_loops > 1000)) {
+                RB_WARN_ON(cpu_buffer, 1);
+                return NULL;
+        }
+
         ts = ring_buffer_time_stamp(cpu_buffer->cpu);
 
         /*
@@ -1043,7 +1101,7 @@ rb_reserve_next_event(struct ring_buffer_per_cpu *cpu_buffer,
 
                 /* Did the write stamp get updated already? */
                 if (unlikely(ts < cpu_buffer->write_stamp))
-                        goto again;
+                        delta = 0;
 
                 if (test_time_stamp(delta)) {
 
@@ -1116,6 +1174,9 @@ ring_buffer_lock_reserve(struct ring_buffer *buffer,
         struct ring_buffer_event *event;
         int cpu, resched;
 
+        if (ring_buffers_off)
+                return NULL;
+
         if (atomic_read(&buffer->record_disabled))
                 return NULL;
 
@@ -1232,6 +1293,9 @@ int ring_buffer_write(struct ring_buffer *buffer,
         int ret = -EBUSY;
         int cpu, resched;
 
+        if (ring_buffers_off)
+                return -EBUSY;
+
         if (atomic_read(&buffer->record_disabled))
                 return -EBUSY;
 
@@ -1530,10 +1594,23 @@ rb_get_reader_page(struct ring_buffer_per_cpu *cpu_buffer)
 {
         struct buffer_page *reader = NULL;
         unsigned long flags;
+        int nr_loops = 0;
 
         spin_lock_irqsave(&cpu_buffer->lock, flags);
 
  again:
+        /*
+         * This should normally only loop twice. But because the
+         * start of the reader inserts an empty page, it causes
+         * a case where we will loop three times. There should be no
+         * reason to loop four times (that I know of).
+         */
+        if (unlikely(++nr_loops > 3)) {
+                RB_WARN_ON(cpu_buffer, 1);
+                reader = NULL;
+                goto out;
+        }
+
         reader = cpu_buffer->reader_page;
 
         /* If there's more to read, return this page */
@@ -1663,6 +1740,7 @@ ring_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts)
         struct ring_buffer_per_cpu *cpu_buffer;
         struct ring_buffer_event *event;
         struct buffer_page *reader;
+        int nr_loops = 0;
 
         if (!cpu_isset(cpu, buffer->cpumask))
                 return NULL;
@@ -1670,6 +1748,19 @@ ring_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts)
         cpu_buffer = buffer->buffers[cpu];
 
  again:
+        /*
+         * We repeat when a timestamp is encountered. It is possible
+         * to get multiple timestamps from an interrupt entering just
+         * as one timestamp is about to be written. The max times
+         * that this can happen is the number of nested interrupts we
+         * can have.  Nesting 10 deep of interrupts is clearly
+         * an anomaly.
+         */
+        if (unlikely(++nr_loops > 10)) {
+                RB_WARN_ON(cpu_buffer, 1);
+                return NULL;
+        }
+
         reader = rb_get_reader_page(cpu_buffer);
         if (!reader)
                 return NULL;
@@ -1720,6 +1811,7 @@ ring_buffer_iter_peek(struct ring_buffer_iter *iter, u64 *ts)
         struct ring_buffer *buffer;
         struct ring_buffer_per_cpu *cpu_buffer;
         struct ring_buffer_event *event;
+        int nr_loops = 0;
 
         if (ring_buffer_iter_empty(iter))
                 return NULL;
@@ -1728,6 +1820,19 @@ ring_buffer_iter_peek(struct ring_buffer_iter *iter, u64 *ts)
         buffer = cpu_buffer->buffer;
 
  again:
+        /*
+         * We repeat when a timestamp is encountered. It is possible
+         * to get multiple timestamps from an interrupt entering just
+         * as one timestamp is about to be written. The max times
+         * that this can happen is the number of nested interrupts we
+         * can have. Nesting 10 deep of interrupts is clearly
+         * an anomaly.
+         */
+        if (unlikely(++nr_loops > 10)) {
+                RB_WARN_ON(cpu_buffer, 1);
+                return NULL;
+        }
+
         if (rb_per_cpu_empty(cpu_buffer))
                 return NULL;
 
@@ -2012,3 +2117,69 @@ int ring_buffer_swap_cpu(struct ring_buffer *buffer_a,
         return 0;
 }
 
+static ssize_t
+rb_simple_read(struct file *filp, char __user *ubuf,
+               size_t cnt, loff_t *ppos)
+{
+        int *p = filp->private_data;
+        char buf[64];
+        int r;
+
+        /* !ring_buffers_off == tracing_on */
+        r = sprintf(buf, "%d\n", !*p);
+
+        return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
+}
+
+static ssize_t
+rb_simple_write(struct file *filp, const char __user *ubuf,
+                size_t cnt, loff_t *ppos)
+{
+        int *p = filp->private_data;
+        char buf[64];
+        long val;
+        int ret;
+
+        if (cnt >= sizeof(buf))
+                return -EINVAL;
+
+        if (copy_from_user(&buf, ubuf, cnt))
+                return -EFAULT;
+
+        buf[cnt] = 0;
+
+        ret = strict_strtoul(buf, 10, &val);
+        if (ret < 0)
+                return ret;
+
+        /* !ring_buffers_off == tracing_on */
+        *p = !val;
+
+        (*ppos)++;
+
+        return cnt;
+}
+
+static struct file_operations rb_simple_fops = {
+        .open           = tracing_open_generic,
+        .read           = rb_simple_read,
+        .write          = rb_simple_write,
+};
+
+
+static __init int rb_init_debugfs(void)
+{
+        struct dentry *d_tracer;
+        struct dentry *entry;
+
+        d_tracer = tracing_init_dentry();
+
+        entry = debugfs_create_file("tracing_on", 0644, d_tracer,
+                                    &ring_buffers_off, &rb_simple_fops);
+        if (!entry)
+                pr_warning("Could not create debugfs 'tracing_on' entry\n");
+
+        return 0;
+}
+
+fs_initcall(rb_init_debugfs);
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index d345d649d073..697eda36b86a 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -34,6 +34,7 @@
 
 #include <linux/stacktrace.h>
 #include <linux/ring_buffer.h>
+#include <linux/irqflags.h>
 
 #include "trace.h"
 
@@ -655,7 +656,11 @@ tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags,
         entry->preempt_count            = pc & 0xff;
         entry->pid                      = (tsk) ? tsk->pid : 0;
         entry->flags =
+#ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT
                 (irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) |
+#else
+                TRACE_FLAG_IRQS_NOSUPPORT |
+#endif
                 ((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) |
                 ((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) |
                 (need_resched() ? TRACE_FLAG_NEED_RESCHED : 0);
@@ -700,6 +705,7 @@ static void ftrace_trace_stack(struct trace_array *tr,
                                unsigned long flags,
                                int skip, int pc)
 {
+#ifdef CONFIG_STACKTRACE
         struct ring_buffer_event *event;
         struct stack_entry *entry;
         struct stack_trace trace;
@@ -725,6 +731,7 @@ static void ftrace_trace_stack(struct trace_array *tr,
 
         save_stack_trace(&trace);
         ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
+#endif
 }
 
 void __trace_stack(struct trace_array *tr,
@@ -851,7 +858,7 @@ ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3)
         preempt_enable_notrace();
 }
 
-#ifdef CONFIG_FTRACE
+#ifdef CONFIG_FUNCTION_TRACER
 static void
 function_trace_call(unsigned long ip, unsigned long parent_ip)
 {
@@ -865,9 +872,6 @@ function_trace_call(unsigned long ip, unsigned long parent_ip)
         if (unlikely(!ftrace_function_enabled))
                 return;
 
-        if (skip_trace(ip))
-                return;
-
         pc = preempt_count();
         resched = need_resched();
         preempt_disable_notrace();
@@ -1084,17 +1088,20 @@ static void s_stop(struct seq_file *m, void *p)
         mutex_unlock(&trace_types_lock);
 }
 
-#define KRETPROBE_MSG "[unknown/kretprobe'd]"
-
 #ifdef CONFIG_KRETPROBES
-static inline int kretprobed(unsigned long addr)
+static inline const char *kretprobed(const char *name)
 {
-        return addr == (unsigned long)kretprobe_trampoline;
+        static const char tramp_name[] = "kretprobe_trampoline";
+        int size = sizeof(tramp_name);
+
+        if (strncmp(tramp_name, name, size) == 0)
+                return "[unknown/kretprobe'd]";
+        return name;
 }
 #else
-static inline int kretprobed(unsigned long addr)
+static inline const char *kretprobed(const char *name)
 {
-        return 0;
+        return name;
 }
 #endif /* CONFIG_KRETPROBES */
 
@@ -1103,10 +1110,13 @@ seq_print_sym_short(struct trace_seq *s, const char *fmt, unsigned long address)
 {
 #ifdef CONFIG_KALLSYMS
         char str[KSYM_SYMBOL_LEN];
+        const char *name;
 
         kallsyms_lookup(address, NULL, NULL, NULL, str);
 
-        return trace_seq_printf(s, fmt, str);
+        name = kretprobed(str);
+
+        return trace_seq_printf(s, fmt, name);
 #endif
         return 1;
 }
@@ -1117,9 +1127,12 @@ seq_print_sym_offset(struct trace_seq *s, const char *fmt,
 {
 #ifdef CONFIG_KALLSYMS
         char str[KSYM_SYMBOL_LEN];
+        const char *name;
 
         sprint_symbol(str, address);
-        return trace_seq_printf(s, fmt, str);
+        name = kretprobed(str);
+
+        return trace_seq_printf(s, fmt, name);
 #endif
         return 1;
 }
@@ -1246,7 +1259,8 @@ lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
         trace_seq_printf(s, "%8.8s-%-5d ", comm, entry->pid);
         trace_seq_printf(s, "%3d", cpu);
         trace_seq_printf(s, "%c%c",
-                        (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' : '.',
+                        (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' :
+                         (entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ? 'X' : '.',
                         ((entry->flags & TRACE_FLAG_NEED_RESCHED) ? 'N' : '.'));
 
         hardirq = entry->flags & TRACE_FLAG_HARDIRQ;
@@ -1372,10 +1386,7 @@ print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu)
 
                 seq_print_ip_sym(s, field->ip, sym_flags);
                 trace_seq_puts(s, " (");
-                if (kretprobed(field->parent_ip))
-                        trace_seq_puts(s, KRETPROBE_MSG);
-                else
-                        seq_print_ip_sym(s, field->parent_ip, sym_flags);
+                seq_print_ip_sym(s, field->parent_ip, sym_flags);
                 trace_seq_puts(s, ")\n");
                 break;
         }
@@ -1491,12 +1502,9 @@ static enum print_line_t print_trace_fmt(struct trace_iterator *iter)
                         ret = trace_seq_printf(s, " <-");
                         if (!ret)
                                 return TRACE_TYPE_PARTIAL_LINE;
-                        if (kretprobed(field->parent_ip))
-                                ret = trace_seq_puts(s, KRETPROBE_MSG);
-                        else
-                                ret = seq_print_ip_sym(s,
-                                                       field->parent_ip,
-                                                       sym_flags);
+                        ret = seq_print_ip_sym(s,
+                                               field->parent_ip,
+                                               sym_flags);
                         if (!ret)
                                 return TRACE_TYPE_PARTIAL_LINE;
                 }
@@ -1747,7 +1755,7 @@ static enum print_line_t print_bin_fmt(struct trace_iterator *iter)
                 return TRACE_TYPE_HANDLED;
 
         SEQ_PUT_FIELD_RET(s, entry->pid);
-        SEQ_PUT_FIELD_RET(s, iter->cpu);
+        SEQ_PUT_FIELD_RET(s, entry->cpu);
         SEQ_PUT_FIELD_RET(s, iter->ts);
 
         switch (entry->type) {
@@ -2379,9 +2387,10 @@ tracing_set_trace_write(struct file *filp, const char __user *ubuf,
         int i;
         size_t ret;
 
+        ret = cnt;
+
         if (cnt > max_tracer_type_len)
                 cnt = max_tracer_type_len;
-        ret = cnt;
 
         if (copy_from_user(&buf, ubuf, cnt))
                 return -EFAULT;
@@ -2414,8 +2423,8 @@ tracing_set_trace_write(struct file *filp, const char __user *ubuf,
  out:
         mutex_unlock(&trace_types_lock);
 
-        if (ret == cnt)
-                filp->f_pos += cnt;
+        if (ret > 0)
+                filp->f_pos += ret;
 
         return ret;
 }
@@ -2667,7 +2676,7 @@ tracing_entries_write(struct file *filp, const char __user *ubuf,
 {
         unsigned long val;
         char buf[64];
-        int ret;
+        int ret, cpu;
         struct trace_array *tr = filp->private_data;
 
         if (cnt >= sizeof(buf))
@@ -2695,6 +2704,14 @@ tracing_entries_write(struct file *filp, const char __user *ubuf,
                 goto out;
         }
 
+        /* disable all cpu buffers */
+        for_each_tracing_cpu(cpu) {
+                if (global_trace.data[cpu])
+                        atomic_inc(&global_trace.data[cpu]->disabled);
+                if (max_tr.data[cpu])
+                        atomic_inc(&max_tr.data[cpu]->disabled);
+        }
+
         if (val != global_trace.entries) {
                 ret = ring_buffer_resize(global_trace.buffer, val);
                 if (ret < 0) {
@@ -2726,6 +2743,13 @@ tracing_entries_write(struct file *filp, const char __user *ubuf,
         if (tracing_disabled)
                 cnt = -ENOMEM;
  out:
+        for_each_tracing_cpu(cpu) {
+                if (global_trace.data[cpu])
+                        atomic_dec(&global_trace.data[cpu]->disabled);
+                if (max_tr.data[cpu])
+                        atomic_dec(&max_tr.data[cpu]->disabled);
+        }
+
         max_tr.entries = global_trace.entries;
         mutex_unlock(&trace_types_lock);
 
@@ -3097,7 +3121,7 @@ void ftrace_dump(void)
         dump_ran = 1;
 
         /* No turning back! */
-        ftrace_kill_atomic();
+        ftrace_kill();
 
         for_each_tracing_cpu(cpu) {
                 atomic_inc(&global_trace.data[cpu]->disabled);
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index f1f99572cde7..8465ad052707 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -120,18 +120,20 @@ struct trace_boot {
 /*
  * trace_flag_type is an enumeration that holds different
  * states when a trace occurs. These are:
- *  IRQS_OFF    - interrupts were disabled
- *  NEED_RESCED - reschedule is requested
- *  HARDIRQ     - inside an interrupt handler
- *  SOFTIRQ     - inside a softirq handler
- *  CONT        - multiple entries hold the trace item
+ *  IRQS_OFF            - interrupts were disabled
+ *  IRQS_NOSUPPORT      - arch does not support irqs_disabled_flags
+ *  NEED_RESCED         - reschedule is requested
+ *  HARDIRQ             - inside an interrupt handler
+ *  SOFTIRQ             - inside a softirq handler
+ *  CONT                - multiple entries hold the trace item
  */
 enum trace_flag_type {
         TRACE_FLAG_IRQS_OFF             = 0x01,
-        TRACE_FLAG_NEED_RESCHED         = 0x02,
-        TRACE_FLAG_HARDIRQ              = 0x04,
-        TRACE_FLAG_SOFTIRQ              = 0x08,
-        TRACE_FLAG_CONT                 = 0x10,
+        TRACE_FLAG_IRQS_NOSUPPORT       = 0x02,
+        TRACE_FLAG_NEED_RESCHED         = 0x04,
+        TRACE_FLAG_HARDIRQ              = 0x08,
+        TRACE_FLAG_SOFTIRQ              = 0x10,
+        TRACE_FLAG_CONT                 = 0x20,
 };
 
 #define TRACE_BUF_SIZE          1024
@@ -335,7 +337,7 @@ void update_max_tr_single(struct trace_array *tr,
 
 extern cycle_t ftrace_now(int cpu);
 
-#ifdef CONFIG_FTRACE
+#ifdef CONFIG_FUNCTION_TRACER
 void tracing_start_function_trace(void);
 void tracing_stop_function_trace(void);
 #else
diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c
index e90eb0c2c56c..0f85a64003d3 100644
--- a/kernel/trace/trace_functions.c
+++ b/kernel/trace/trace_functions.c
@@ -64,7 +64,7 @@ static void function_trace_ctrl_update(struct trace_array *tr)
 
 static struct tracer function_trace __read_mostly =
 {
-        .name        = "ftrace",
+        .name        = "function",
         .init        = function_trace_init,
         .reset       = function_trace_reset,
         .ctrl_update = function_trace_ctrl_update,
diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c
index a7db7f040ae0..9c74071c10e0 100644
--- a/kernel/trace/trace_irqsoff.c
+++ b/kernel/trace/trace_irqsoff.c
@@ -63,7 +63,7 @@ irq_trace(void)
  */
 static __cacheline_aligned_in_smp       unsigned long max_sequence;
 
-#ifdef CONFIG_FTRACE
+#ifdef CONFIG_FUNCTION_TRACER
 /*
  * irqsoff uses its own tracer function to keep the overhead down:
  */
@@ -104,7 +104,7 @@ static struct ftrace_ops trace_ops __read_mostly =
 {
         .func = irqsoff_tracer_call,
 };
-#endif /* CONFIG_FTRACE */
+#endif /* CONFIG_FUNCTION_TRACER */
 
 /*
  * Should this new latency be reported/recorded?
diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c
index fe4a252c2363..3ae93f16b565 100644
--- a/kernel/trace/trace_sched_wakeup.c
+++ b/kernel/trace/trace_sched_wakeup.c
@@ -31,7 +31,7 @@ static raw_spinlock_t wakeup_lock =
 
 static void __wakeup_reset(struct trace_array *tr);
 
-#ifdef CONFIG_FTRACE
+#ifdef CONFIG_FUNCTION_TRACER
 /*
  * irqsoff uses its own tracer function to keep the overhead down:
  */
@@ -96,7 +96,7 @@ static struct ftrace_ops trace_ops __read_mostly =
 {
         .func = wakeup_tracer_call,
 };
-#endif /* CONFIG_FTRACE */
+#endif /* CONFIG_FUNCTION_TRACER */
 
 /*
  * Should this new latency be reported/recorded?
diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c
index 09cf230d7eca..90bc752a7580 100644
--- a/kernel/trace/trace_selftest.c
+++ b/kernel/trace/trace_selftest.c
@@ -70,7 +70,7 @@ static int trace_test_buffer(struct trace_array *tr, unsigned long *count)
         return ret;
 }
 
-#ifdef CONFIG_FTRACE
+#ifdef CONFIG_FUNCTION_TRACER
 
 #ifdef CONFIG_DYNAMIC_FTRACE
 
@@ -99,13 +99,6 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace,
         /* passed in by parameter to fool gcc from optimizing */
         func();
 
-        /* update the records */
-        ret = ftrace_force_update();
-        if (ret) {
-                printk(KERN_CONT ".. ftraced failed .. ");
-                return ret;
-        }
-
         /*
          * Some archs *cough*PowerPC*cough* add charachters to the
          * start of the function names. We simply put a '*' to
@@ -183,13 +176,6 @@ trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr)
         /* make sure msleep has been recorded */
         msleep(1);
 
-        /* force the recorded functions to be traced */
-        ret = ftrace_force_update();
-        if (ret) {
-                printk(KERN_CONT ".. ftraced failed .. ");
-                return ret;
-        }
-
         /* start the tracing */
         ftrace_enabled = 1;
         tracer_enabled = 1;
@@ -226,7 +212,7 @@ trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr)
 
         return ret;
 }
-#endif /* CONFIG_FTRACE */
+#endif /* CONFIG_FUNCTION_TRACER */
 
 #ifdef CONFIG_IRQSOFF_TRACER
 int
diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
index 74c5d9a3afae..be682b62fe58 100644
--- a/kernel/trace/trace_stack.c
+++ b/kernel/trace/trace_stack.c
@@ -44,6 +44,10 @@ static inline void check_stack(void)
         if (this_size <= max_stack_size)
                 return;
 
+        /* we do not handle interrupt stacks yet */
+        if (!object_is_on_stack(&this_size))
+                return;
+
         raw_local_irq_save(flags);
         __raw_spin_lock(&max_stack_lock);