diff options
Diffstat (limited to 'tools/perf/builtin-ftrace.c')
| -rw-r--r-- | tools/perf/builtin-ftrace.c | 18 |
1 files changed, 16 insertions, 2 deletions
diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c index 25a42acabee1..f42f228e8899 100644 --- a/tools/perf/builtin-ftrace.c +++ b/tools/perf/builtin-ftrace.c @@ -72,6 +72,7 @@ static int __write_tracing_file(const char *name, const char *val, bool append) ssize_t size = strlen(val); int flags = O_WRONLY; char errbuf[512]; + char *val_copy; file = get_tracing_file(name); if (!file) { @@ -91,12 +92,23 @@ static int __write_tracing_file(const char *name, const char *val, bool append) goto out; } - if (write(fd, val, size) == size) + /* + * 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); @@ -280,8 +292,10 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv) signal(SIGCHLD, sig_handler); signal(SIGPIPE, sig_handler); - if (reset_tracing_files(ftrace) < 0) + if (reset_tracing_files(ftrace) < 0) { + pr_err("failed to reset ftrace\n"); goto out; + } /* reset ftrace buffer */ if (write_tracing_file("trace", "0") < 0) |