Merge branch 'tracing-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'tracing-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (28 commits)
  ftrace: Add function names to dangling } in function graph tracer
  tracing: Simplify memory recycle of trace_define_field
  tracing: Remove unnecessary variable in print_graph_return
  tracing: Fix typo of info text in trace_kprobe.c
  tracing: Fix typo in prof_sysexit_enable()
  tracing: Remove CONFIG_TRACE_POWER from kernel config
  tracing: Fix ftrace_event_call alignment for use with gcc 4.5
  ftrace: Remove memory barriers from NMI code when not needed
  tracing/kprobes: Add short documentation for HAVE_REGS_AND_STACK_ACCESS_API
  s390: Add pt_regs register and stack access API
  tracing/kprobes: Make Kconfig dependencies generic
  tracing: Unify arch_syscall_addr() implementations
  tracing: Add notrace to TRACE_EVENT implementation functions
  ftrace: Allow to remove a single function from function graph filter
  tracing: Add correct/incorrect to sort keys for branch annotation output
  tracing: Simplify test for function_graph tracing start point
  tracing: Drop the tr check from the graph tracing path
  tracing: Add stack dump to trace_printk if stacktrace option is set
  tracing: Use appropriate perl constructs in recordmcount.pl
  tracing: optimize recordmcount.pl for offsets-handling
  ...

1 files changed, 46 insertions, 62 deletions

diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 50b1b8239806..465b36bef4ca 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -651,12 +651,12 @@ static int create_trace_probe(int argc, char **argv)
                         event = strchr(group, '/') + 1;
                         event[-1] = '\0';
                         if (strlen(group) == 0) {
-                                pr_info("Group name is not specifiled\n");
+                                pr_info("Group name is not specified\n");
                                 return -EINVAL;
                         }
                 }
                 if (strlen(event) == 0) {
-                        pr_info("Event name is not specifiled\n");
+                        pr_info("Event name is not specified\n");
                         return -EINVAL;
                 }
         }
@@ -1174,80 +1174,60 @@ static int kretprobe_event_define_fields(struct ftrace_event_call *event_call)
         return 0;
 }
 
-static int __probe_event_show_format(struct trace_seq *s,
-                                     struct trace_probe *tp, const char *fmt,
-                                     const char *arg)
+static int __set_print_fmt(struct trace_probe *tp, char *buf, int len)
 {
         int i;
+        int pos = 0;
 
-        /* Show format */
-        if (!trace_seq_printf(s, "\nprint fmt: \"%s", fmt))
-                return 0;
+        const char *fmt, *arg;
 
-        for (i = 0; i < tp->nr_args; i++)
-                if (!trace_seq_printf(s, " %s=%%lx", tp->args[i].name))
-                        return 0;
+        if (!probe_is_return(tp)) {
+                fmt = "(%lx)";
+                arg = "REC->" FIELD_STRING_IP;
+        } else {
+                fmt = "(%lx <- %lx)";
+                arg = "REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP;
+        }
 
-        if (!trace_seq_printf(s, "\", %s", arg))
-                return 0;
+        /* When len=0, we just calculate the needed length */
+#define LEN_OR_ZERO (len ? len - pos : 0)
 
-        for (i = 0; i < tp->nr_args; i++)
-                if (!trace_seq_printf(s, ", REC->%s", tp->args[i].name))
-                        return 0;
+        pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt);
 
-        return trace_seq_puts(s, "\n");
-}
+        for (i = 0; i < tp->nr_args; i++) {
+                pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=%%lx",
+                                tp->args[i].name);
+        }
 
-#undef SHOW_FIELD
-#define SHOW_FIELD(type, item, name)                                    \
-        do {                                                            \
-                ret = trace_seq_printf(s, "\tfield:" #type " %s;\t"     \
-                                "offset:%u;\tsize:%u;\tsigned:%d;\n", name,\
-                                (unsigned int)offsetof(typeof(field), item),\
-                                (unsigned int)sizeof(type),             \
-                                is_signed_type(type));                  \
-                if (!ret)                                               \
-                        return 0;                                       \
-        } while (0)
+        pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg);
 
-static int kprobe_event_show_format(struct ftrace_event_call *call,
-                                    struct trace_seq *s)
-{
-        struct kprobe_trace_entry field __attribute__((unused));
-        int ret, i;
-        struct trace_probe *tp = (struct trace_probe *)call->data;
-
-        SHOW_FIELD(unsigned long, ip, FIELD_STRING_IP);
-        SHOW_FIELD(int, nargs, FIELD_STRING_NARGS);
+        for (i = 0; i < tp->nr_args; i++) {
+                pos += snprintf(buf + pos, LEN_OR_ZERO, ", REC->%s",
+                                tp->args[i].name);
+        }
 
-        /* Show fields */
-        for (i = 0; i < tp->nr_args; i++)
-                SHOW_FIELD(unsigned long, args[i], tp->args[i].name);
-        trace_seq_puts(s, "\n");
+#undef LEN_OR_ZERO
 
-        return __probe_event_show_format(s, tp, "(%lx)",
-                                         "REC->" FIELD_STRING_IP);
+        /* return the length of print_fmt */
+        return pos;
 }
 
-static int kretprobe_event_show_format(struct ftrace_event_call *call,
-                                       struct trace_seq *s)
+static int set_print_fmt(struct trace_probe *tp)
 {
-        struct kretprobe_trace_entry field __attribute__((unused));
-        int ret, i;
-        struct trace_probe *tp = (struct trace_probe *)call->data;
+        int len;
+        char *print_fmt;
 
-        SHOW_FIELD(unsigned long, func, FIELD_STRING_FUNC);
-        SHOW_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP);
-        SHOW_FIELD(int, nargs, FIELD_STRING_NARGS);
+        /* First: called with 0 length to calculate the needed length */
+        len = __set_print_fmt(tp, NULL, 0);
+        print_fmt = kmalloc(len + 1, GFP_KERNEL);
+        if (!print_fmt)
+                return -ENOMEM;
 
-        /* Show fields */
-        for (i = 0; i < tp->nr_args; i++)
-                SHOW_FIELD(unsigned long, args[i], tp->args[i].name);
-        trace_seq_puts(s, "\n");
+        /* Second: actually write the @print_fmt */
+        __set_print_fmt(tp, print_fmt, len + 1);
+        tp->call.print_fmt = print_fmt;
 
-        return __probe_event_show_format(s, tp, "(%lx <- %lx)",
-                                         "REC->" FIELD_STRING_FUNC
-                                         ", REC->" FIELD_STRING_RETIP);
+        return 0;
 }
 
 #ifdef CONFIG_EVENT_PROFILE
@@ -1448,18 +1428,20 @@ static int register_probe_event(struct trace_probe *tp)
         if (probe_is_return(tp)) {
                 tp->event.trace = print_kretprobe_event;
                 call->raw_init = probe_event_raw_init;
-                call->show_format = kretprobe_event_show_format;
                 call->define_fields = kretprobe_event_define_fields;
         } else {
                 tp->event.trace = print_kprobe_event;
                 call->raw_init = probe_event_raw_init;
-                call->show_format = kprobe_event_show_format;
                 call->define_fields = kprobe_event_define_fields;
         }
+        if (set_print_fmt(tp) < 0)
+                return -ENOMEM;
         call->event = &tp->event;
         call->id = register_ftrace_event(&tp->event);
-        if (!call->id)
+        if (!call->id) {
+                kfree(call->print_fmt);
                 return -ENODEV;
+        }
         call->enabled = 0;
         call->regfunc = probe_event_enable;
         call->unregfunc = probe_event_disable;
@@ -1472,6 +1454,7 @@ static int register_probe_event(struct trace_probe *tp)
         ret = trace_add_event_call(call);
         if (ret) {
                 pr_info("Failed to register kprobe event: %s\n", call->name);
+                kfree(call->print_fmt);
                 unregister_ftrace_event(&tp->event);
         }
         return ret;
@@ -1481,6 +1464,7 @@ static void unregister_probe_event(struct trace_probe *tp)
 {
         /* tp->event is unregistered in trace_remove_event_call() */
         trace_remove_event_call(&tp->call);
+        kfree(tp->call.print_fmt);
 }
 
 /* Make a debugfs interface for controling probe points */