[PATCH] selftests/exec: allow shell return code of 126

When the shell fails to invoke a script because its path name
is too long (ENAMETOOLONG), most shells return 127 to indicate
command not found.  However, some systems report 126 (which POSIX
suggests should indicate a non-executable file) for this case,
so allow that too.

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: David Drysdale <redacted>
---
 tools/testing/selftests/exec/execveat.c | 28 ++++++++++++++++++++++------
 1 file changed, 22 insertions(+), 6 deletions(-)

diff --git a/tools/testing/selftests/exec/execveat.c b/tools/testing/selftests/exec/execveat.c
index d273624c93a6..0d940c6e26bd 100644
--- a/tools/testing/selftests/exec/execveat.c
+++ b/tools/testing/selftests/exec/execveat.c

@@ -62,7 +62,7 @@ static int _check_execveat_fail(int fd, const char *path, int flags,
 }
 
 static int check_execveat_invoked_rc(int fd, const char *path, int flags,
-				     int expected_rc)
+				     int expected_rc, int expected_rc2)
 {
 	int status;
 	int rc;

@@ -99,9 +99,19 @@ static int check_execveat_invoked_rc(int fd, const char *path, int flags,
 		return 1;
 	}
 	if (WEXITSTATUS(status) != expected_rc) {
-		printf("[FAIL] (child %d exited with %d not %d)\n",
-			child, WEXITSTATUS(status), expected_rc);
-		return 1;
+		if (expected_rc != expected_rc2) {
+			if (WEXITSTATUS(status) != expected_rc2) {
+				printf("[FAIL] (child %d exited with %d;"
+					" not %d nor %d)\n",
+					child, WEXITSTATUS(status),
+					expected_rc, expected_rc2);
+				return 1;
+			}
+		} else {
+			printf("[FAIL] (child %d exited with %d not %d)\n",
+				child, WEXITSTATUS(status), expected_rc);
+			return 1;
+		}
 	}
 	printf("[OK]\n");
 	return 0;

@@ -109,7 +119,7 @@ static int check_execveat_invoked_rc(int fd, const char *path, int flags,
 
 static int check_execveat(int fd, const char *path, int flags)
 {
-	return check_execveat_invoked_rc(fd, path, flags, 99);
+	return check_execveat_invoked_rc(fd, path, flags, 99, 99);
 }
 
 static char *concat(const char *left, const char *right)

@@ -192,9 +202,15 @@ static int check_execveat_pathmax(int dot_dfd, const char *src, int is_script)
 	 * Execute as a long pathname relative to ".".  If this is a script,
 	 * the interpreter will launch but fail to open the script because its
 	 * name ("/dev/fd/5/xxx....") is bigger than PATH_MAX.
+	 *
+	 * The failure code is usually 127 (POSIX: "If a command is not found,
+	 * the exit status shall be 127."), but some systems give 126 (POSIX:
+	 * "If the command name is found, but it is not an executable utility,
+	 * the exit status shall be 126."), so allow either.
 	 */
 	if (is_script)
-		fail += check_execveat_invoked_rc(dot_dfd, longpath, 0, 127);
+		fail += check_execveat_invoked_rc(dot_dfd, longpath, 0,
+						  127, 126);
 	else
 		fail += check_execveat(dot_dfd, longpath, 0);
 

-- 
2.2.0.rc0.207.ga3a616c

On Mon, Jan 5, 2015 at 12:19 PM, David Drysdale [off-list ref] wrote:

When the shell fails to invoke a script because its path name
is too long (ENAMETOOLONG), most shells return 127 to indicate
command not found.  However, some systems report 126 (which POSIX
suggests should indicate a non-executable file) for this case,
so allow that too.

Thanks, after this patch, the execveat selftest succeeds on m68k with
Debian 4.0.

Reported-by: Geert Uytterhoeven <redacted>
Signed-off-by: David Drysdale <redacted>

Tested-by: Geert Uytterhoeven <redacted>

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert-Td1EMuHUCqxL1ZNQvxDV9g@public.gmane.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

On 01/05/2015 04:19 AM, David Drysdale wrote:

This logic doesn't scale well if there other expected return
values to account for. Please think about a re-write to handle
multiple expected return codes.

Please collapse expected_rc and expected_rc2 checks. You can rephrase
the error message to work for both cases.

thanks,
-- Shuah

-- 
Shuah Khan
Sr. Linux Kernel Developer
Open Source Innovation Group
Samsung Research America (Silicon Valley)
shuahkh-JPH+aEBZ4P+UEJcrhfAQsw@public.gmane.org | (970) 217-8978

On Mon, Jan 5, 2015 at 7:03 PM, Shuah Khan [off-list ref] wrote:

On 01/05/2015 04:19 AM, David Drysdale wrote:

quoted

When the shell fails to invoke a script because its path name
is too long (ENAMETOOLONG), most shells return 127 to indicate
command not found.  However, some systems report 126 (which POSIX
suggests should indicate a non-executable file) for this case,
so allow that too.

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: David Drysdale <redacted>
---
 tools/testing/selftests/exec/execveat.c | 28 ++++++++++++++++++++++------
 1 file changed, 22 insertions(+), 6 deletions(-)

diff --git a/tools/testing/selftests/exec/execveat.c b/tools/testing/selftests/exec/execveat.c
index d273624c93a6..0d940c6e26bd 100644
--- a/tools/testing/selftests/exec/execveat.c
+++ b/tools/testing/selftests/exec/execveat.c

@@ -62,7 +62,7 @@ static int _check_execveat_fail(int fd, const char *path, int flags,
 }

 static int check_execveat_invoked_rc(int fd, const char *path, int flags,
-                                  int expected_rc)
+                                  int expected_rc, int expected_rc2)

This logic doesn't scale well if there other expected return
values to account for. Please think about a re-write to handle
multiple expected return codes.

I don't think it needs to scale -- even having a second possible return
code was a bit of a surprise.

quoted

 {
      int status;
      int rc;

@@ -99,9 +99,19 @@ static int check_execveat_invoked_rc(int fd, const char *path, int flags,
              return 1;
      }
      if (WEXITSTATUS(status) != expected_rc) {
-             printf("[FAIL] (child %d exited with %d not %d)\n",
-                     child, WEXITSTATUS(status), expected_rc);
-             return 1;
+             if (expected_rc != expected_rc2) {

Please collapse expected_rc and expected_rc2 checks. You can rephrase
the error message to work for both cases.

OK, will do.

thanks,
-- Shuah

--
Shuah Khan
Sr. Linux Kernel Developer
Open Source Innovation Group
Samsung Research America (Silicon Valley)
shuahkh@osg.samsung.com | (970) 217-8978