[PATCH 3/3] tracing: add format files for ftrace default entries

From: Steven Rostedt
Date: Thu Mar 05 2009 - 22:20:53 EST

Next message: Gautham R Shenoy: "Re: [v2 PATCH 4/4] timers: logic to enable timer migration."
Previous message: Steven Rostedt: "[PATCH 2/3] tracing: move print of event format to separate file"
In reply to: Steven Rostedt: "[PATCH 2/3] tracing: move print of event format to separate file"
Next in thread: Ingo Molnar: "Re: [PATCH 0/3] [GIT PULL] for tip/tracing/ftrace"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

From: Steven Rostedt <srostedt@xxxxxxxxxx>

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: Steven Rostedt <srostedt@xxxxxxxxxx>
---
kernel/trace/Makefile | 1 +
kernel/trace/trace_event_types.h | 165 ++++++++++++++++++++++++++++++++++++++
kernel/trace/trace_events.c | 12 ++-
kernel/trace/trace_export.c | 81 +++++++++++++++++++
kernel/trace/trace_format.h | 2 +-
5 files changed, 255 insertions(+), 6 deletions(-)
create mode 100644 kernel/trace/trace_event_types.h
create mode 100644 kernel/trace/trace_export.c

diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile
index c931fe0..f44736c 100644
--- a/kernel/trace/Makefile
+++ b/kernel/trace/Makefile
@@ -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
diff --git a/kernel/trace/trace_event_types.h b/kernel/trace/trace_event_types.h
new file mode 100644
index 0000000..fb4eba1
--- /dev/null
+++ b/kernel/trace/trace_event_types.h
@@ -0,0 +1,165 @@
+#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
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 210e71f..4488d90 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -656,11 +656,13 @@ event_create_dir(struct ftrace_event_call *call, struct dentry *d_events)
return -1;
}

- 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);
+ 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",
diff --git a/kernel/trace/trace_export.c b/kernel/trace/trace_export.c
new file mode 100644
index 0000000..0fb7be7
--- /dev/null
+++ b/kernel/trace/trace_export.c
@@ -0,0 +1,81 @@
+/*
+ * trace_export.c - export basic ftrace utilities to user space
+ *
+ * Copyright (C) 2009 Steven Rostedt <srostedt@xxxxxxxxxx>
+ */
+#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"
diff --git a/kernel/trace/trace_format.h b/kernel/trace/trace_format.h
index 53a6b13..03f9a4c 100644
--- a/kernel/trace/trace_format.h
+++ b/kernel/trace/trace_format.h
@@ -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; \
--
1.6.1.3

--
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

Next message: Gautham R Shenoy: "Re: [v2 PATCH 4/4] timers: logic to enable timer migration."
Previous message: Steven Rostedt: "[PATCH 2/3] tracing: move print of event format to separate file"
In reply to: Steven Rostedt: "[PATCH 2/3] tracing: move print of event format to separate file"
Next in thread: Ingo Molnar: "Re: [PATCH 0/3] [GIT PULL] for tip/tracing/ftrace"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]