// SPDX-License-Identifier: GPL-2.0-only
/*
* builtin-ftrace.c
*
* Copyright (c) 2013 LG Electronics, Namhyung Kim <namhyung@kernel.org>
* Copyright (c) 2020 Changbin Du <changbin.du@gmail.com>, significant enhancement.
*/
#include "builtin.h"
#include <errno.h>
#include <unistd.h>
#include <signal.h>
#include <stdlib.h>
#include <fcntl.h>
#include <math.h>
#include <poll.h>
#include <ctype.h>
#include <linux/capability.h>
#include <linux/string.h>
#include "debug.h"
#include <subcmd/pager.h>
#include <subcmd/parse-options.h>
#include <api/fs/tracing_path.h>
#include "evlist.h"
#include "target.h"
#include "cpumap.h"
#include "thread_map.h"
#include "strfilter.h"
#include "util/cap.h"
#include "util/config.h"
#include "util/ftrace.h"
#include "util/units.h"
#include "util/parse-sublevel-options.h"
#define DEFAULT_TRACER "function_graph"
static volatile sig_atomic_t workload_exec_errno;
static volatile sig_atomic_t done;
static void sig_handler(int sig __maybe_unused)
{
done = true;
}
/*
* evlist__prepare_workload will send a SIGUSR1 if the fork fails, since
* we asked by setting its exec_error to the function below,
* ftrace__workload_exec_failed_signal.
*
* XXX We need to handle this more appropriately, emitting an error, etc.
*/
static void ftrace__workload_exec_failed_signal(int signo __maybe_unused,
siginfo_t *info __maybe_unused,
void *ucontext __maybe_unused)
{
workload_exec_errno = info->si_value.sival_int;
done = true;
}
static int __write_tracing_file(const char *name, const char *val, bool append)
{
char *file;
int fd, ret = -1;
ssize_t size = strlen(val);
int flags = O_WRONLY;
char errbuf[512];
char *val_copy;
file = get_tracing_file(name);
if (!file) {
pr_debug("cannot get tracing file: %s\n", name);
return -1;
}
if (append)
flags |= O_APPEND;
else
flags |= O_TRUNC;
fd = open(file, flags);
if (fd < 0) {
pr_debug("cannot open tracing file: %s: %s\n",
name, str_error_r(errno, errbuf, sizeof(errbuf)));
goto out;
}
/*
* Copy the original value and append a '\n'. Without this,
* the kernel can hide possible errors.
*/
val_copy = strdup(val);
if (!val_copy)
goto out_close;
val_copy[size] = '\n';
if (write(fd, val_copy, size + 1) == size + 1)
ret = 0;
else
pr_debug("write '%s' to tracing/%s failed: %s\n",
val, name, str_error_r(errno, errbuf, sizeof(errbuf)));
free(val_copy);
out_close:
close(fd);
out:
put_tracing_file(file);
return ret;
}
static int write_tracing_file(const char *name, const char *val)
{
return __write_tracing_file(name, val, 