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

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

[David Drysdale]

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 <drysdale@google.com>
---
 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

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

[Geert Uytterhoeven]

On Mon, Jan 5, 2015 at 12:19 PM, David Drysdale <drysdale-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org> 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 <geert-Td1EMuHUCqxL1ZNQvxDV9g@public.gmane.org>
> Signed-off-by: David Drysdale <drysdale-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>

Tested-by: Geert Uytterhoeven <geert-Td1EMuHUCqxL1ZNQvxDV9g@public.gmane.org>

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

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

[Shuah Khan]

On 01/05/2015 04:19 AM, David Drysdale 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.
> 
> Reported-by: Geert Uytterhoeven <geert-Td1EMuHUCqxL1ZNQvxDV9g@public.gmane.org>
> Signed-off-by: David Drysdale <drysdale-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
> ---
>  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.


>  {
>  	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.

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

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

[David Drysdale]

On Mon, Jan 5, 2015 at 7:03 PM, Shuah Khan <shuahkh@osg.samsung.com> wrote:
> On 01/05/2015 04:19 AM, David Drysdale 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.
>>
>> Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
>> Signed-off-by: David Drysdale <drysdale@google.com>
>> ---
>>  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.

>>  {
>>       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