As trace-stack.c's read_proc() function is going to be used by trace-cmd stat, we don't want it to make the program die in case something went wrong. Therefore, this simple patch makes read_proc() to just return -1 in case the proc file was empty or read() failed with an error, instead of using die().
Signed-off-by: Vladislav Valtchev (VMware) <[email protected]> --- trace-stack.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/trace-stack.c b/trace-stack.c index fada62d..3e1e41b 100644 --- a/trace-stack.c +++ b/trace-stack.c @@ -79,7 +79,7 @@ static int read_proc(int *status) close(fd); if (n <= 0) - die("error reading %s", PROC_FILE); + return -1; if (n >= sizeof(buf)) return -1; @@ -101,6 +101,7 @@ static void change_stack_tracer_status(unsigned new_status) { char buf[1]; int status; + int ret; int fd; int n; @@ -109,7 +110,11 @@ static void change_stack_tracer_status(unsigned new_status) return; } - if (read_proc(&status) > 0 && status == new_status) + ret = read_proc(&status); + if (ret < 0) + die("error reading %s", PROC_FILE); + + if (ret > 0 && status == new_status) return; /* nothing to do */ fd = open(PROC_FILE, O_WRONLY); -- 2.14.1
