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Commit 770cb243 authored by Steven Rostedt's avatar Steven Rostedt
Browse files

tracing: add format files for ftrace default entries 



Impact: allow user apps to read binary format of basic ftrace entries

Currently, only defined raw events export their formats so a binary
reader can parse them. There's no reason that the default ftrace entries
can't export their formats.

This patch adds a subsystem called "ftrace" in the events directory
that includes the ftrace entries for basic ftrace recorded items.

These only have three files in the events directory:

 type             : printf
 available_types  : printf
 format           : format for the event entry

For example:

 # cat /debug/tracing/events/ftrace/wakeup/format
name: wakeup
ID: 3
format:
        field:unsigned char type;       offset:0;       size:1;
        field:unsigned char flags;      offset:1;       size:1;
        field:unsigned char preempt_count;      offset:2;       size:1;
        field:int pid;  offset:4;       size:4;
        field:int tgid; offset:8;       size:4;

        field:unsigned int prev_pid;    offset:12;      size:4;
        field:unsigned char prev_prio;  offset:16;      size:1;
        field:unsigned char prev_state; offset:17;      size:1;
        field:unsigned int next_pid;    offset:20;      size:4;
        field:unsigned char next_prio;  offset:24;      size:1;
        field:unsigned char next_state; offset:25;      size:1;
        field:unsigned int next_cpu;    offset:28;      size:4;

print fmt: "%u:%u:%u  ==+ %u:%u:%u [%03u]"

Signed-off-by: default avatarSteven Rostedt <srostedt@redhat.com>
parent 33b0c229

kernel/trace/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -41,5 +41,6 @@ obj-$(CONFIG_WORKQUEUE_TRACER) += trace_workqueue.o 
obj-$(CONFIG_BLK_DEV_IO_TRACE)	+= blktrace.o

obj-$(CONFIG_EVENT_TRACER) += trace_events.o

obj-$(CONFIG_EVENT_TRACER) += events.o

obj-$(CONFIG_EVENT_TRACER) += trace_export.o



libftrace-y := ftrace.o

kernel/trace/trace_event_types.h

0 → 100644
+165 −0
Original line number Diff line number Diff line 
#undef TRACE_SYSTEM

#define TRACE_SYSTEM	ftrace



/*

 * We cheat and use the proto type field as the ID

 * and args as the entry type (minus 'struct')

 */

TRACE_EVENT_FORMAT(function, TRACE_FN, ftrace_entry, ignore,

	TRACE_STRUCT(

		TRACE_FIELD(unsigned long, ip, ip)

		TRACE_FIELD(unsigned long, parent_ip, parent_ip)

	),

	TPRAWFMT(" %lx <-- %lx")

);



TRACE_EVENT_FORMAT(funcgraph_entry, TRACE_GRAPH_ENT,

		   ftrace_graph_ent_entry, ignore,

	TRACE_STRUCT(

		TRACE_FIELD(unsigned long, graph_ent.func, func)

		TRACE_FIELD(int, graph_ent.depth, depth)

	),

	TPRAWFMT("--> %lx (%d)")

);



TRACE_EVENT_FORMAT(funcgraph_exit, TRACE_GRAPH_RET,

		   ftrace_graph_ret_entry, ignore,

	TRACE_STRUCT(

		TRACE_FIELD(unsigned long, ret.func, func)

		TRACE_FIELD(int, ret.depth, depth)

	),

	TPRAWFMT("<-- %lx (%d)")

);



TRACE_EVENT_FORMAT(wakeup, TRACE_WAKE, ctx_switch_entry, ignore,

	TRACE_STRUCT(

		TRACE_FIELD(unsigned int, prev_pid, prev_pid)

		TRACE_FIELD(unsigned char, prev_prio, prev_prio)

		TRACE_FIELD(unsigned char, prev_state, prev_state)

		TRACE_FIELD(unsigned int, next_pid, next_pid)

		TRACE_FIELD(unsigned char, next_prio, next_prio)

		TRACE_FIELD(unsigned char, next_state, next_state)

		TRACE_FIELD(unsigned int, next_cpu, next_cpu)

	),

	TPRAWFMT("%u:%u:%u  ==+ %u:%u:%u [%03u]")

);



TRACE_EVENT_FORMAT(context_switch, TRACE_CTX, ctx_switch_entry, ignore,

	TRACE_STRUCT(

		TRACE_FIELD(unsigned int, prev_pid, prev_pid)

		TRACE_FIELD(unsigned char, prev_prio, prev_prio)

		TRACE_FIELD(unsigned char, prev_state, prev_state)

		TRACE_FIELD(unsigned int, next_pid, next_pid)

		TRACE_FIELD(unsigned char, next_prio, next_prio)

		TRACE_FIELD(unsigned char, next_state, next_state)

		TRACE_FIELD(unsigned int, next_cpu, next_cpu)

	),

	TPRAWFMT("%u:%u:%u  ==+ %u:%u:%u [%03u]")

);



TRACE_EVENT_FORMAT(special, TRACE_SPECIAL, special_entry, ignore,

	TRACE_STRUCT(

		TRACE_FIELD(unsigned long, arg1, arg1)

		TRACE_FIELD(unsigned long, arg2, arg2)

		TRACE_FIELD(unsigned long, arg3, arg3)

	),

	TPRAWFMT("(%08lx) (%08lx) (%08lx)")

);



/*

 * Stack-trace entry:

 */



/* #define FTRACE_STACK_ENTRIES   8 */



TRACE_EVENT_FORMAT(kernel_stack, TRACE_STACK, stack_entry, ignore,

	TRACE_STRUCT(

		TRACE_FIELD(unsigned long, caller[0], stack0)

		TRACE_FIELD(unsigned long, caller[1], stack1)

		TRACE_FIELD(unsigned long, caller[2], stack2)

		TRACE_FIELD(unsigned long, caller[3], stack3)

		TRACE_FIELD(unsigned long, caller[4], stack4)

		TRACE_FIELD(unsigned long, caller[5], stack5)

		TRACE_FIELD(unsigned long, caller[6], stack6)

		TRACE_FIELD(unsigned long, caller[7], stack7)

	),

	TPRAWFMT("\t=> (%08lx)\n\t=> (%08lx)\n\t=> (%08lx)\n\t=> (%08lx)\n"

		 "\t=> (%08lx)\n\t=> (%08lx)\n\t=> (%08lx)\n\t=> (%08lx)\n")

);



TRACE_EVENT_FORMAT(user_stack, TRACE_USER_STACK, userstack_entry, ignore,

	TRACE_STRUCT(

		TRACE_FIELD(unsigned long, caller[0], stack0)

		TRACE_FIELD(unsigned long, caller[1], stack1)

		TRACE_FIELD(unsigned long, caller[2], stack2)

		TRACE_FIELD(unsigned long, caller[3], stack3)

		TRACE_FIELD(unsigned long, caller[4], stack4)

		TRACE_FIELD(unsigned long, caller[5], stack5)

		TRACE_FIELD(unsigned long, caller[6], stack6)

		TRACE_FIELD(unsigned long, caller[7], stack7)

	),

	TPRAWFMT("\t=> (%08lx)\n\t=> (%08lx)\n\t=> (%08lx)\n\t=> (%08lx)\n"

		 "\t=> (%08lx)\n\t=> (%08lx)\n\t=> (%08lx)\n\t=> (%08lx)\n")

);



TRACE_EVENT_FORMAT(print, TRACE_PRINT, print_entry, ignore,

	TRACE_STRUCT(

		TRACE_FIELD(unsigned long, ip, ip)

		TRACE_FIELD(unsigned int, depth, depth)

		TRACE_FIELD_ZERO_CHAR(buf)

	),

	TPRAWFMT("%08lx (%d) %s")

);



TRACE_EVENT_FORMAT(branch, TRACE_BRANCH, trace_branch, ignore,

	TRACE_STRUCT(

		TRACE_FIELD(unsigned int, line, line)

		TRACE_FIELD_SPECIAL(char func[TRACE_FUNC_SIZE+1], func, func)

		TRACE_FIELD_SPECIAL(char file[TRACE_FUNC_SIZE+1], file, file)

		TRACE_FIELD(char, correct, correct)

	),

	TPRAWFMT("%u:%s:%s (%u)")

);



TRACE_EVENT_FORMAT(hw_branch, TRACE_HW_BRANCHES, hw_branch_entry, ignore,

	TRACE_STRUCT(

		TRACE_FIELD(u64, from, from)

		TRACE_FIELD(u64, to, to)

	),

	TPRAWFMT("from: %llx to: %llx")

);



TRACE_EVENT_FORMAT(power, TRACE_POWER, trace_power, ignore,

	TRACE_STRUCT(

		TRACE_FIELD(ktime_t, state_data.stamp, stamp)

		TRACE_FIELD(ktime_t, state_data.end, end)

		TRACE_FIELD(int, state_data.type, type)

		TRACE_FIELD(int, state_data.state, state)

	),

	TPRAWFMT("%llx->%llx type:%u state:%u")

);



TRACE_EVENT_FORMAT(kmem_alloc, TRACE_KMEM_ALLOC, kmemtrace_alloc_entry, ignore,

	TRACE_STRUCT(

		TRACE_FIELD(enum kmemtrace_type_id, type_id, type_id)

		TRACE_FIELD(unsigned long, call_site, call_site)

		TRACE_FIELD(const void *, ptr, ptr)

		TRACE_FIELD(size_t, bytes_req, bytes_req)

		TRACE_FIELD(size_t, bytes_alloc, bytes_alloc)

		TRACE_FIELD(gfp_t, gfp_flags, gfp_flags)

		TRACE_FIELD(int, node, node)

	),

	TPRAWFMT("type:%u call_site:%lx ptr:%p req:%lu alloc:%lu"

		 " flags:%x node:%d")

);



TRACE_EVENT_FORMAT(kmem_free, TRACE_KMEM_FREE, kmemtrace_free_entry, ignore,

	TRACE_STRUCT(

		TRACE_FIELD(enum kmemtrace_type_id, type_id, type_id)

		TRACE_FIELD(unsigned long, call_site, call_site)

		TRACE_FIELD(const void *, ptr, ptr)

	),

	TPRAWFMT("type:%u call_site:%lx ptr:%p")

);



#undef TRACE_SYSTEM

kernel/trace/trace_events.c

+7 −5
Original line number Diff line number Diff line
@@ -656,11 +656,13 @@ event_create_dir(struct ftrace_event_call *call, struct dentry *d_events) 
		return -1;

	}



	if (call->regfunc) {

		entry = debugfs_create_file("enable", 0644, call->dir, call,

					    &ftrace_enable_fops);

		if (!entry)

			pr_warning("Could not create debugfs "

				   "'%s/enable' entry\n", call->name);

	}



	/* Only let type be writable, if we can change it */

	entry = debugfs_create_file("type",

kernel/trace/trace_export.c

0 → 100644
+81 −0
Original line number Diff line number Diff line 
/*

 * trace_export.c - export basic ftrace utilities to user space

 *

 * Copyright (C) 2009 Steven Rostedt <srostedt@redhat.com>

 */

#include <linux/stringify.h>

#include <linux/kallsyms.h>

#include <linux/seq_file.h>

#include <linux/debugfs.h>

#include <linux/uaccess.h>

#include <linux/ftrace.h>

#include <linux/module.h>

#include <linux/init.h>

#include <linux/fs.h>



#include "trace_output.h"



#include "trace_format.h"



#undef TRACE_FIELD_ZERO_CHAR

#define TRACE_FIELD_ZERO_CHAR(item)				\

	ret = trace_seq_printf(s, "\tfield: char " #item ";\t"	\

			       "offset:%lu;\tsize:0;\n",	\

			       offsetof(typeof(field), item));	\

	if (!ret)						\

		return 0;





#undef TPRAWFMT

#define TPRAWFMT(args...) args



#undef TRACE_EVENT_FORMAT

#define TRACE_EVENT_FORMAT(call, proto, args, fmt, tstruct, tpfmt)	\

static int								\

ftrace_format_##call(struct trace_seq *s)				\

{									\

	struct args field;						\

	int ret;							\

									\

	tstruct;							\

									\

	trace_seq_printf(s, "\nprint fmt: \"%s\"\n", tpfmt);		\

									\

	return ret;							\

}



#include "trace_event_types.h"



#undef TRACE_ZERO_CHAR

#define TRACE_ZERO_CHAR(arg)



#undef TRACE_FIELD

#define TRACE_FIELD(type, item, assign)\

	entry->item = assign;



#undef TRACE_FIELD

#define TRACE_FIELD(type, item, assign)\

	entry->item = assign;



#undef TPCMD

#define TPCMD(cmd...)	cmd



#undef TRACE_ENTRY

#define TRACE_ENTRY	entry



#undef TRACE_FIELD_SPECIAL

#define TRACE_FIELD_SPECIAL(type_item, item, cmd) \

	cmd;



#undef TRACE_EVENT_FORMAT

#define TRACE_EVENT_FORMAT(call, proto, args, fmt, tstruct, tpfmt)	\

									\

static struct ftrace_event_call __used					\

__attribute__((__aligned__(4)))						\

__attribute__((section("_ftrace_events"))) event_##call = {		\

	.name 			= #call,				\

	.id			= proto,				\

	.system			= __stringify(TRACE_SYSTEM),		\

	.show_format		= ftrace_format_##call,			\

}

#include "trace_event_types.h"

kernel/trace/trace_format.h

+1 −1
Original line number Diff line number Diff line
@@ -40,7 +40,7 @@ 


#undef TRACE_EVENT_FORMAT

#define TRACE_EVENT_FORMAT(call, proto, args, fmt, tstruct, tpfmt)	\

int									\

static int								\

ftrace_format_##call(struct trace_seq *s)				\

{									\

	struct ftrace_raw_##call field;					\