7 files changed, 208 insertions, 176 deletions

diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index 3595a4c14aba..26b2d92d48b3 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -347,7 +347,7 @@ void ftrace_nmi_exit(void)
 
 /* Add a function return address to the trace stack on thread info.*/
 static int push_return_trace(unsigned long ret, unsigned long long time,
-                                unsigned long func)
+                                unsigned long func, int *depth)
 {
         int index;
 
@@ -365,21 +365,22 @@ static int push_return_trace(unsigned long ret, unsigned long long time,
         current->ret_stack[index].ret = ret;
         current->ret_stack[index].func = func;
         current->ret_stack[index].calltime = time;
+        *depth = index;
 
         return 0;
 }
 
 /* Retrieve a function return address to the trace stack on thread info.*/
-static void pop_return_trace(unsigned long *ret, unsigned long long *time,
-                                unsigned long *func, unsigned long *overrun)
+static void pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret)
 {
         int index;
 
         index = current->curr_ret_stack;
         *ret = current->ret_stack[index].ret;
-        *func = current->ret_stack[index].func;
-        *time = current->ret_stack[index].calltime;
-        *overrun = atomic_read(&current->trace_overrun);
+        trace->func = current->ret_stack[index].func;
+        trace->calltime = current->ret_stack[index].calltime;
+        trace->overrun = atomic_read(&current->trace_overrun);
+        trace->depth = index;
         current->curr_ret_stack--;
 }
 
@@ -390,12 +391,13 @@ static void pop_return_trace(unsigned long *ret, unsigned long long *time,
 unsigned long ftrace_return_to_handler(void)
 {
         struct ftrace_graph_ret trace;
-        pop_return_trace(&trace.ret, &trace.calltime, &trace.func,
-                        &trace.overrun);
+        unsigned long ret;
+
+        pop_return_trace(&trace, &ret);
         trace.rettime = cpu_clock(raw_smp_processor_id());
-        ftrace_graph_function(&trace);
+        ftrace_graph_return(&trace);
 
-        return trace.ret;
+        return ret;
 }
 
 /*
@@ -407,6 +409,7 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
         unsigned long old;
         unsigned long long calltime;
         int faulted;
+        struct ftrace_graph_ent trace;
         unsigned long return_hooker = (unsigned long)
                                 &return_to_handler;
 
@@ -452,8 +455,15 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
 
         calltime = cpu_clock(raw_smp_processor_id());
 
-        if (push_return_trace(old, calltime, self_addr) == -EBUSY)
+        if (push_return_trace(old, calltime,
+                                self_addr, &trace.depth) == -EBUSY) {
                 *parent = old;
+                return;
+        }
+
+        trace.func = self_addr;
+        ftrace_graph_entry(&trace);
+
 }
 
 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index b4ac734ad8d6..fc2d54987198 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -313,26 +313,39 @@ ftrace_init_module(struct module *mod,
 
 
 /*
+ * Structure that defines an entry function trace.
+ */
+struct ftrace_graph_ent {
+        unsigned long func; /* Current function */
+        int depth;
+};
+
+/*
  * Structure that defines a return function trace.
  */
 struct ftrace_graph_ret {
-        unsigned long ret; /* Return address */
         unsigned long func; /* Current function */
         unsigned long long calltime;
         unsigned long long rettime;
         /* Number of functions that overran the depth limit for current task */
         unsigned long overrun;
+        int depth;
 };
 
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 #define FTRACE_RETFUNC_DEPTH 50
 #define FTRACE_RETSTACK_ALLOC_SIZE 32
-/* Type of a callback handler of tracing return function */
-typedef void (*trace_function_graph_t)(struct ftrace_graph_ret *);
+/* 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 */
+
+extern int register_ftrace_graph(trace_func_graph_ret_t retfunc,
+                                trace_func_graph_ent_t entryfunc);
+
+/* The current handlers in use */
+extern trace_func_graph_ret_t ftrace_graph_return;
+extern trace_func_graph_ent_t ftrace_graph_entry;
 
-extern int register_ftrace_graph(trace_function_graph_t func);
-/* The current handler in use */
-extern trace_function_graph_t ftrace_graph_function;
 extern void unregister_ftrace_graph(void);
 
 extern void ftrace_graph_init_task(struct task_struct *t);
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 9e19976af727..7e2d3b91692d 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1498,12 +1498,13 @@ ftrace_enable_sysctl(struct ctl_table *table, int write,
 
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 
-static atomic_t ftrace_retfunc_active;
-
-/* The callback that hooks the return of a function */
-trace_function_graph_t ftrace_graph_function =
-                        (trace_function_graph_t)ftrace_stub;
+static atomic_t ftrace_graph_active;
 
+/* 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;
 
 /* 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)
@@ -1569,7 +1570,8 @@ static int start_graph_tracing(void)
         return ret;
 }
 
-int register_ftrace_graph(trace_function_graph_t func)
+int register_ftrace_graph(trace_func_graph_ret_t retfunc,
+                        trace_func_graph_ent_t entryfunc)
 {
         int ret = 0;
 
@@ -1583,14 +1585,15 @@ int register_ftrace_graph(trace_function_graph_t func)
                 ret = -EBUSY;
                 goto out;
         }
-        atomic_inc(&ftrace_retfunc_active);
+        atomic_inc(&ftrace_graph_active);
         ret = start_graph_tracing();
         if (ret) {
-                atomic_dec(&ftrace_retfunc_active);
+                atomic_dec(&ftrace_graph_active);
                 goto out;
         }
         ftrace_tracing_type = FTRACE_TYPE_RETURN;
-        ftrace_graph_function = func;
+        ftrace_graph_return = retfunc;
+        ftrace_graph_entry = entryfunc;
         ftrace_startup();
 
 out:
@@ -1602,8 +1605,9 @@ void unregister_ftrace_graph(void)
 {
         mutex_lock(&ftrace_sysctl_lock);
 
-        atomic_dec(&ftrace_retfunc_active);
-        ftrace_graph_function = (trace_function_graph_t)ftrace_stub;
+        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_shutdown();
         /* Restore normal tracing type */
         ftrace_tracing_type = FTRACE_TYPE_ENTER;
@@ -1614,7 +1618,7 @@ void unregister_ftrace_graph(void)
 /* Allocate a return stack for newly created task */
 void ftrace_graph_init_task(struct task_struct *t)
 {
-        if (atomic_read(&ftrace_retfunc_active)) {
+        if (atomic_read(&ftrace_graph_active)) {
                 t->ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
                                 * sizeof(struct ftrace_ret_stack),
                                 GFP_KERNEL);
@@ -1638,5 +1642,3 @@ void ftrace_graph_exit_task(struct task_struct *t)
 }
 #endif
 
-
-
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index f21ab2c68fd4..9d5f7c94f251 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -879,14 +879,38 @@ trace_function(struct trace_array *tr, struct trace_array_cpu *data,
 }
 
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
-static void __trace_function_graph(struct trace_array *tr,
+static void __trace_graph_entry(struct trace_array *tr,
+                                struct trace_array_cpu *data,
+                                struct ftrace_graph_ent *trace,
+                                unsigned long flags,
+                                int pc)
+{
+        struct ring_buffer_event *event;
+        struct ftrace_graph_ent_entry *entry;
+        unsigned long irq_flags;
+
+        if (unlikely(local_read(&__get_cpu_var(ftrace_cpu_disabled))))
+                return;
+
+        event = ring_buffer_lock_reserve(global_trace.buffer, sizeof(*entry),
+                                         &irq_flags);
+        if (!event)
+                return;
+        entry   = ring_buffer_event_data(event);
+        tracing_generic_entry_update(&entry->ent, flags, pc);
+        entry->ent.type                 = TRACE_GRAPH_ENT;
+        entry->graph_ent                        = *trace;
+        ring_buffer_unlock_commit(global_trace.buffer, event, irq_flags);
+}
+
+static void __trace_graph_return(struct trace_array *tr,
                                 struct trace_array_cpu *data,
                                 struct ftrace_graph_ret *trace,
                                 unsigned long flags,
                                 int pc)
 {
         struct ring_buffer_event *event;
-        struct ftrace_graph_entry *entry;
+        struct ftrace_graph_ret_entry *entry;
         unsigned long irq_flags;
 
         if (unlikely(local_read(&__get_cpu_var(ftrace_cpu_disabled))))
@@ -898,12 +922,8 @@ static void __trace_function_graph(struct trace_array *tr,
                 return;
         entry   = ring_buffer_event_data(event);
         tracing_generic_entry_update(&entry->ent, flags, pc);
-        entry->ent.type                 = TRACE_FN_RET;
-        entry->ip                       = trace->func;
-        entry->parent_ip        = trace->ret;
-        entry->rettime          = trace->rettime;
-        entry->calltime         = trace->calltime;
-        entry->overrun          = trace->overrun;
+        entry->ent.type                 = TRACE_GRAPH_RET;
+        entry->ret                              = *trace;
         ring_buffer_unlock_commit(global_trace.buffer, event, irq_flags);
 }
 #endif
@@ -1178,7 +1198,7 @@ function_trace_call(unsigned long ip, unsigned long parent_ip)
 }
 
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
-void trace_function_graph(struct ftrace_graph_ret *trace)
+void trace_graph_entry(struct ftrace_graph_ent *trace)
 {
         struct trace_array *tr = &global_trace;
         struct trace_array_cpu *data;
@@ -1193,7 +1213,28 @@ void trace_function_graph(struct ftrace_graph_ret *trace)
         disabled = atomic_inc_return(&data->disabled);
         if (likely(disabled == 1)) {
                 pc = preempt_count();
-                __trace_function_graph(tr, data, trace, flags, pc);
+                __trace_graph_entry(tr, data, trace, flags, pc);
+        }
+        atomic_dec(&data->disabled);
+        raw_local_irq_restore(flags);
+}
+
+void trace_graph_return(struct ftrace_graph_ret *trace)
+{
+        struct trace_array *tr = &global_trace;
+        struct trace_array_cpu *data;
+        unsigned long flags;
+        long disabled;
+        int cpu;
+        int pc;
+
+        raw_local_irq_save(flags);
+        cpu = raw_smp_processor_id();
+        data = tr->data[cpu];
+        disabled = atomic_inc_return(&data->disabled);
+        if (likely(disabled == 1)) {
+                pc = preempt_count();
+                __trace_graph_return(tr, data, trace, flags, pc);
         }
         atomic_dec(&data->disabled);
         raw_local_irq_restore(flags);
@@ -2000,9 +2041,11 @@ static enum print_line_t print_trace_fmt(struct trace_iterator *iter)
                         trace_seq_print_cont(s, iter);
                 break;
         }
-        case TRACE_FN_RET: {
+        case TRACE_GRAPH_RET: {
+                return print_graph_function(iter);
+        }
+        case TRACE_GRAPH_ENT: {
                 return print_graph_function(iter);
-                break;
         }
         case TRACE_BRANCH: {
                 struct trace_branch *field;
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 72b5ef868765..ffe1bb1eb620 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -25,7 +25,8 @@ enum trace_type {
         TRACE_BRANCH,
         TRACE_BOOT_CALL,
         TRACE_BOOT_RET,
-        TRACE_FN_RET,
+        TRACE_GRAPH_RET,
+        TRACE_GRAPH_ENT,
         TRACE_USER_STACK,
         TRACE_BTS,
 
@@ -56,14 +57,16 @@ struct ftrace_entry {
         unsigned long           parent_ip;
 };
 
+/* Function call entry */
+struct ftrace_graph_ent_entry {
+        struct trace_entry                      ent;
+        struct ftrace_graph_ent         graph_ent;
+};
+
 /* Function return entry */
-struct ftrace_graph_entry {
-        struct trace_entry      ent;
-        unsigned long           ip;
-        unsigned long           parent_ip;
-        unsigned long long      calltime;
-        unsigned long long      rettime;
-        unsigned long           overrun;
+struct ftrace_graph_ret_entry {
+        struct trace_entry                      ent;
+        struct ftrace_graph_ret         ret;
 };
 extern struct tracer boot_tracer;
 
@@ -264,7 +267,10 @@ extern void __ftrace_bad_type(void);
                 IF_ASSIGN(var, ent, struct trace_boot_call, TRACE_BOOT_CALL);\
                 IF_ASSIGN(var, ent, struct trace_boot_ret, TRACE_BOOT_RET);\
                 IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
-                IF_ASSIGN(var, ent, struct ftrace_graph_entry, TRACE_FN_RET);\
+                IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,      \
+                          TRACE_GRAPH_ENT);             \
+                IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,      \
+                          TRACE_GRAPH_RET);             \
                 IF_ASSIGN(var, ent, struct bts_entry, TRACE_BTS);\
                 __ftrace_bad_type();                                    \
         } while (0)
@@ -397,9 +403,9 @@ void trace_function(struct trace_array *tr,
                     unsigned long ip,
                     unsigned long parent_ip,
                     unsigned long flags, int pc);
-void
-trace_function_graph(struct ftrace_graph_ret *trace);
 
+void trace_graph_return(struct ftrace_graph_ret *trace);
+void trace_graph_entry(struct ftrace_graph_ent *trace);
 void trace_bts(struct trace_array *tr,
                unsigned long from,
                unsigned long to);
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index f5bad4624d2b..b6f0cc2a00cb 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -13,6 +13,7 @@
 
 #include "trace.h"
 
+#define TRACE_GRAPH_INDENT      2
 
 #define TRACE_GRAPH_PRINT_OVERRUN       0x1
 static struct tracer_opt trace_opts[] = {
@@ -26,6 +27,8 @@ static struct tracer_flags tracer_flags = {
         .opts = trace_opts
 };
 
+/* pid on the last trace processed */
+static pid_t last_pid = -1;
 
 static int graph_trace_init(struct trace_array *tr)
 {
@@ -33,7 +36,8 @@ static int graph_trace_init(struct trace_array *tr)
         for_each_online_cpu(cpu)
                 tracing_reset(tr, cpu);
 
-        return register_ftrace_graph(&trace_function_graph);
+        return register_ftrace_graph(&trace_graph_return,
+                                        &trace_graph_entry);
 }
 
 static void graph_trace_reset(struct trace_array *tr)
@@ -41,45 +45,97 @@ static void graph_trace_reset(struct trace_array *tr)
                 unregister_ftrace_graph();
 }
 
+/* If the pid changed since the last trace, output this event */
+static int verif_pid(struct trace_seq *s, pid_t pid)
+{
+        if (last_pid != -1 && last_pid == pid)
+                return 1;
 
-enum print_line_t
-print_graph_function(struct trace_iterator *iter)
+        last_pid = pid;
+        return trace_seq_printf(s, "\n------------8<---------- thread %d"
+                                    " ------------8<----------\n\n",
+                                  pid);
+}
+
+static enum print_line_t
+print_graph_entry(struct ftrace_graph_ent *call, struct trace_seq *s,
+                struct trace_entry *ent)
 {
-        struct trace_seq *s = &iter->seq;
-        struct trace_entry *entry = iter->ent;
-        struct ftrace_graph_entry *field;
+        int i;
         int ret;
 
-        if (entry->type == TRACE_FN_RET) {
-                trace_assign_type(field, entry);
-                ret = trace_seq_printf(s, "%pF -> ", (void *)field->parent_ip);
-                if (!ret)
-                        return TRACE_TYPE_PARTIAL_LINE;
+        if (!verif_pid(s, ent->pid))
+                return TRACE_TYPE_PARTIAL_LINE;
 
-                ret = seq_print_ip_sym(s, field->ip,
-                                        trace_flags & TRACE_ITER_SYM_MASK);
+        for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
+                ret = trace_seq_printf(s, " ");
                 if (!ret)
                         return TRACE_TYPE_PARTIAL_LINE;
+        }
+
+        ret = seq_print_ip_sym(s, call->func, 0);
+        if (!ret)
+                return TRACE_TYPE_PARTIAL_LINE;
+
+        ret = trace_seq_printf(s, "() {\n");
+        if (!ret)
+                return TRACE_TYPE_PARTIAL_LINE;
+        return TRACE_TYPE_HANDLED;
+}
+
+static enum print_line_t
+print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,
+                   struct trace_entry *ent)
+{
+        int i;
+        int ret;
+
+        if (!verif_pid(s, ent->pid))
+                return TRACE_TYPE_PARTIAL_LINE;
 
-                ret = trace_seq_printf(s, " (%llu ns)",
-                                        field->rettime - field->calltime);
+        for (i = 0; i < trace->depth * TRACE_GRAPH_INDENT; 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;
 
-                if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERRUN) {
-                        ret = trace_seq_printf(s, " (Overruns: %lu)",
-                                                field->overrun);
-                        if (!ret)
-                                return TRACE_TYPE_PARTIAL_LINE;
-                }
+        ret = trace_seq_printf(s, "%llu\n", trace->rettime - trace->calltime);
+        if (!ret)
+                return TRACE_TYPE_PARTIAL_LINE;
 
-                ret = trace_seq_printf(s, "\n");
+        if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERRUN) {
+                ret = trace_seq_printf(s, " (Overruns: %lu)\n",
+                                        trace->overrun);
                 if (!ret)
                         return TRACE_TYPE_PARTIAL_LINE;
+        }
+        return TRACE_TYPE_HANDLED;
+}
+
+enum print_line_t
+print_graph_function(struct trace_iterator *iter)
+{
+        struct trace_seq *s = &iter->seq;
+        struct trace_entry *entry = iter->ent;
 
-                return TRACE_TYPE_HANDLED;
+        switch (entry->type) {
+        case TRACE_GRAPH_ENT: {
+                struct ftrace_graph_ent_entry *field;
+                trace_assign_type(field, entry);
+                return print_graph_entry(&field->graph_ent, s, entry);
+        }
+        case TRACE_GRAPH_RET: {
+                struct ftrace_graph_ret_entry *field;
+                trace_assign_type(field, entry);
+                return print_graph_return(&field->ret, s, entry);
+        }
+        default:
+                return TRACE_TYPE_UNHANDLED;
         }
-        return TRACE_TYPE_UNHANDLED;
 }
 
 static struct tracer graph_trace __read_mostly = {
diff --git a/kernel/trace/trace_functions_return.c b/kernel/trace/trace_functions_return.c
deleted file mode 100644
index e00d64509c9c..000000000000
--- a/kernel/trace/trace_functions_return.c
+++ /dev/null
@@ -1,98 +0,0 @@
-/*
- *
- * Function return tracer.
- * Copyright (c) 2008 Frederic Weisbecker <fweisbec@gmail.com>
- * Mostly borrowed from function tracer which
- * is Copyright (c) Steven Rostedt <srostedt@redhat.com>
- *
- */
-#include <linux/debugfs.h>
-#include <linux/uaccess.h>
-#include <linux/ftrace.h>
-#include <linux/fs.h>
-
-#include "trace.h"
-
-
-#define TRACE_RETURN_PRINT_OVERRUN      0x1
-static struct tracer_opt trace_opts[] = {
-        /* Display overruns or not */
-        { TRACER_OPT(overrun, TRACE_RETURN_PRINT_OVERRUN) },
-        { } /* Empty entry */
-};
-
-static struct tracer_flags tracer_flags = {
-        .val = 0, /* Don't display overruns by default */
-        .opts = trace_opts
-};
-
-
-static int return_trace_init(struct trace_array *tr)
-{
-        int cpu;
-        for_each_online_cpu(cpu)
-                tracing_reset(tr, cpu);
-
-        return register_ftrace_return(&trace_function_return);
-}
-
-static void return_trace_reset(struct trace_array *tr)
-{
-                unregister_ftrace_return();
-}
-
-
-enum print_line_t
-print_return_function(struct trace_iterator *iter)
-{
-        struct trace_seq *s = &iter->seq;
-        struct trace_entry *entry = iter->ent;
-        struct ftrace_ret_entry *field;
-        int ret;
-
-        if (entry->type == TRACE_FN_RET) {
-                trace_assign_type(field, entry);
-                ret = trace_seq_printf(s, "%pF -> ", (void *)field->parent_ip);
-                if (!ret)
-                        return TRACE_TYPE_PARTIAL_LINE;
-
-                ret = seq_print_ip_sym(s, field->ip,
-                                        trace_flags & TRACE_ITER_SYM_MASK);
-                if (!ret)
-                        return TRACE_TYPE_PARTIAL_LINE;
-
-                ret = trace_seq_printf(s, " (%llu ns)",
-                                        field->rettime - field->calltime);
-                if (!ret)
-                        return TRACE_TYPE_PARTIAL_LINE;
-
-                if (tracer_flags.val & TRACE_RETURN_PRINT_OVERRUN) {
-                        ret = trace_seq_printf(s, " (Overruns: %lu)",
-                                                field->overrun);
-                        if (!ret)
-                                return TRACE_TYPE_PARTIAL_LINE;
-                }
-
-                ret = trace_seq_printf(s, "\n");
-                if (!ret)
-                        return TRACE_TYPE_PARTIAL_LINE;
-
-                return TRACE_TYPE_HANDLED;
-        }
-        return TRACE_TYPE_UNHANDLED;
-}
-
-static struct tracer return_trace __read_mostly = {
-        .name        = "return",
-        .init        = return_trace_init,
-        .reset       = return_trace_reset,
-        .print_line = print_return_function,
-        .flags          = &tracer_flags,
-};
-
-static __init int init_return_trace(void)
-{
-        return register_tracer(&return_trace);
-}
-
-device_initcall(init_return_trace);