Commit dc4ddb4c authored by Frederic Weisbecker's avatar Frederic Weisbecker

tracing: Add fields format definition for syscall events

Define the format of the syscall trace fields to parse the binary
values from a raw trace using the syscall events "format" file.

This is defined dynamically using the syscalls metadata.
It prepares the export of syscall event raw records to perf
counters.

Example:

$ cat /debug/tracing/events/syscalls/sys_enter_sched_getparam/format
name: sys_enter_sched_getparam
ID: 39
format:
	field:unsigned short common_type;	offset:0;	size:2;
	field:unsigned char common_flags;	offset:2;	size:1;
	field:unsigned char common_preempt_count;	offset:3;	size:1;
	field:int common_pid;	offset:4;	size:4;
	field:int common_tgid;	offset:8;	size:4;

	field:pid_t pid;	offset:12;	size:8;
	field:struct sched_param * param;	offset:20;	size:8;

print fmt: "pid: 0x%08lx, param: 0x%08lx", ((unsigned long)(REC->pid)), ((unsigned long)(REC->param))
Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Jiaying Zhang <jiayingz@google.com>
Cc: Martin Bligh <mbligh@google.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Jason Baron <jbaron@redhat.com>
parent e8f9f4d7
......@@ -189,6 +189,7 @@ static void prof_sysexit_disable_##sname(struct ftrace_event_call *event_call) \
.system = "syscalls", \
.event = &event_syscall_enter, \
.raw_init = init_enter_##sname, \
.show_format = ftrace_format_syscall, \
.regfunc = reg_event_syscall_enter, \
.unregfunc = unreg_event_syscall_enter, \
.data = "sys"#sname, \
......
......@@ -55,6 +55,8 @@ extern int reg_event_syscall_enter(void *ptr);
extern void unreg_event_syscall_enter(void *ptr);
extern int reg_event_syscall_exit(void *ptr);
extern void unreg_event_syscall_exit(void *ptr);
extern int
ftrace_format_syscall(struct ftrace_event_call *call, struct trace_seq *s);
enum print_line_t print_syscall_enter(struct trace_iterator *iter, int flags);
enum print_line_t print_syscall_exit(struct trace_iterator *iter, int flags);
#endif
......
......@@ -105,6 +105,52 @@ print_syscall_exit(struct trace_iterator *iter, int flags)
return TRACE_TYPE_HANDLED;
}
int ftrace_format_syscall(struct ftrace_event_call *call, struct trace_seq *s)
{
int i;
int nr;
int ret = 0;
struct syscall_metadata *entry;
int offset = sizeof(struct trace_entry);
nr = syscall_name_to_nr((char *)call->data);
entry = syscall_nr_to_meta(nr);
if (!entry)
return ret;
for (i = 0; i < entry->nb_args; i++) {
ret = trace_seq_printf(s, "\tfield:%s %s;", entry->types[i],
entry->args[i]);
if (!ret)
return 0;
ret = trace_seq_printf(s, "\toffset:%d;\tsize:%lu;\n", offset,
sizeof(unsigned long));
if (!ret)
return 0;
offset += sizeof(unsigned long);
}
trace_seq_printf(s, "\nprint fmt: \"");
for (i = 0; i < entry->nb_args; i++) {
ret = trace_seq_printf(s, "%s: 0x%%0%lulx%s", entry->args[i],
sizeof(unsigned long),
i == entry->nb_args - 1 ? "\", " : ", ");
if (!ret)
return 0;
}
for (i = 0; i < entry->nb_args; i++) {
ret = trace_seq_printf(s, "((unsigned long)(REC->%s))%s",
entry->args[i],
i == entry->nb_args - 1 ? "\n" : ", ");
if (!ret)
return 0;
}
return ret;
}
void ftrace_syscall_enter(struct pt_regs *regs, long id)
{
struct syscall_trace_enter *entry;
......
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