selftests/exec: Check if the syscall exists and bail if not (9a0b5745) · Commits · e / devices / android_kernel_samsung_universal8895

On systems which don't implement sys_execveat(), this test produces a lot of output. Add a check at the beginning to see if the syscall is present, and if not just note one error and return. When we run on a system that doesn't implement the syscall we will get ENOSYS back from the kernel, so change the logic that handles __NR_execveat not being defined to also use ENOSYS rather than -ENOSYS. Signed-off-by:

Michael Ellerman <mpe@ellerman.id.au> Acked-by:

David Drysdale <drysdale@google.com> Signed-off-by:

Shuah Khan <shuahkh@osg.samsung.com>

tools/testing/selftests/exec/execveat.c

+9 −1

Original line number	Diff line number	Diff line
		@@ -30,7 +30,7 @@ static int execveat_(int fd, const char path, char argv, char *envp,
		#ifdef __NR_execveat
		return syscall(__NR_execveat, fd, path, argv, envp, flags);
		#else
		errno = -ENOSYS;
		errno = ENOSYS;
		return -1;
		#endif
		}
		@@ -234,6 +234,14 @@ static int run_tests(void)
		int fd_cloexec = open_or_die("execveat", O_RDONLY\|O_CLOEXEC);
		int fd_script_cloexec = open_or_die("script", O_RDONLY\|O_CLOEXEC);

		/* Check if we have execveat at all, and bail early if not */
		errno = 0;
		execveat_(-1, NULL, NULL, NULL, 0);
		if (errno == ENOSYS) {
		printf("[FAIL] ENOSYS calling execveat - no kernel support?\n");
		return 1;
		}

		/* Change file position to confirm it doesn't affect anything */
		lseek(fd, 10, SEEK_SET);