This adds an option '-l/--list-functions' to list all available functions which is read from tracing file 'available_filter_functions'.
Signed-off-by: Changbin Du <[email protected]> --- tools/perf/builtin-ftrace.c | 43 +++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c index 1d30c2d5f88b..8133d910d5d8 100644 --- a/tools/perf/builtin-ftrace.c +++ b/tools/perf/builtin-ftrace.c @@ -33,6 +33,7 @@ struct perf_ftrace { struct evlist *evlist; struct target target; const char *tracer; + bool list_avail_functions; struct list_head filters; struct list_head notrace; struct list_head graph_funcs; @@ -142,6 +143,43 @@ static int write_tracing_option_file(const char *name, const char *val) return ret; } +static int read_tracing_file_to_stdout(const char *name) +{ + char buf[4096]; + char *file; + int fd; + int ret = -1; + + file = get_tracing_file(name); + if (!file) { + pr_debug("cannot get tracing file: %s\n", name); + return -1; + } + + fd = open(file, O_RDONLY); + if (fd < 0) { + pr_debug("cannot open tracing file: %s: %s\n", + name, str_error_r(errno, buf, sizeof(buf))); + goto out; + } + + /* read contents to stdout */ + while (true) { + int n = read(fd, buf, sizeof(buf)); + if (n <= 0) + goto out_close; + if (fwrite(buf, n, 1, stdout) != 1) + goto out_close; + } + ret = 0; + +out_close: + close(fd); +out: + put_tracing_file(file); + return ret; +} + static int reset_tracing_cpu(void); static void reset_tracing_filters(void); @@ -332,6 +370,9 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv) signal(SIGCHLD, sig_handler); signal(SIGPIPE, sig_handler); + if (ftrace->list_avail_functions) + return read_tracing_file_to_stdout("available_filter_functions"); + if (reset_tracing_files(ftrace) < 0) { pr_err("failed to reset ftrace\n"); goto out; @@ -483,6 +524,8 @@ int cmd_ftrace(int argc, const char **argv) NULL }; const struct option ftrace_options[] = { + OPT_BOOLEAN('L', "list-functions", &ftrace.list_avail_functions, + "List available functions to filter"), OPT_STRING('p', "pid", &ftrace.target.pid, "pid", "trace on existing process id"), OPT_INCR('v', "verbose", &verbose, -- 2.25.1
