__fatal_error routine doesn't check strerror_r() return value, which results in the following compile time warning:
posix_timers.c: In function ‘__fatal_error’: posix_timers.c:31:9: warning: ignoring return value of ‘strerror_r’ declared with attribute ‘warn_unused_result’ [-Wunused-result] 31 | strerror_r(errno, buf, sizeof(buf));
Fix this by adding a check for return value and error handling appropriate for the GNU-specific strerror_r() in use in __fatal_error(). Check if return string is null and handle accordingly.
From Linux strerror_r() manual page:
"The GNU-specific strerror_r() returns a pointer to a string containing the error message. This may be either a pointer to a string that the function stores in buf, or a pointer to some (immutable) static string (in which case buf is unused). If the function stores a string in buf, then at most buflen bytes are stored (the string may be truncated if buflen is too small and errnum is unknown). The string always includes a terminating null byte."
Signed-off-by: Shuah Khan skhan@linuxfoundation.org --- tools/testing/selftests/timers/posix_timers.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/tools/testing/selftests/timers/posix_timers.c b/tools/testing/selftests/timers/posix_timers.c index 16bd49492efa..ddb1cebc844e 100644 --- a/tools/testing/selftests/timers/posix_timers.c +++ b/tools/testing/selftests/timers/posix_timers.c @@ -26,13 +26,17 @@ static void __fatal_error(const char *test, const char *name, const char *what) { char buf[64]; + char *ret_str = NULL;
- strerror_r(errno, buf, sizeof(buf)); + ret_str = strerror_r(errno, buf, sizeof(buf));
- if (name && strlen(name)) - ksft_exit_fail_msg("%s %s %s %s\n", test, name, what, buf); + if (name && strlen(name) && ret_str) + ksft_exit_fail_msg("%s %s %s %s\n", test, name, what, ret_str); + else if (ret_str) + ksft_exit_fail_msg("%s %s %s\n", test, what, ret_str); else - ksft_exit_fail_msg("%s %s %s\n", test, what, buf); + ksft_exit_fail_msg("%s %s\n", test, what); + }
#define fatal_error(name, what) __fatal_error(__func__, name, what)