[2/3] Linux: unlockpt needs to fail with EINVAL, not ENOTTY (bug 26053)

Message ID a5c22488f136c3532d4b0b30d5461c45bada08f7.1596611597.git.fweimer@redhat.com
State New
Headers show
Series
  • [1/3] login/tst-grantpt: Convert to support framework, more error checking
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Commit Message

Vitaly Buka via Libc-alpha Aug. 5, 2020, 7:14 a.m.
The EINVAL error code is mandated by POSIX and documented in the
manual.  Also clean up the unlockpt implementation a bit, assuming
that TIOCSPTLCK is always defined.

Enhance login/tst-grantpt to cover unlockpt corner cases.
---
 login/tst-grantpt.c                | 20 ++++++++++++++++----
 sysdeps/unix/sysv/linux/unlockpt.c | 21 +++++----------------
 2 files changed, 21 insertions(+), 20 deletions(-)

-- 
2.26.2

Comments

Vitaly Buka via Libc-alpha Aug. 13, 2020, 6:30 p.m. | #1
On 05/08/2020 04:14, Florian Weimer via Libc-alpha wrote:
> The EINVAL error code is mandated by POSIX and documented in the

> manual.  Also clean up the unlockpt implementation a bit, assuming

> that TIOCSPTLCK is always defined.

> 

> Enhance login/tst-grantpt to cover unlockpt corner cases.


LGTM, thanks.

Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>


> ---

>  login/tst-grantpt.c                | 20 ++++++++++++++++----

>  sysdeps/unix/sysv/linux/unlockpt.c | 21 +++++----------------

>  2 files changed, 21 insertions(+), 20 deletions(-)

> 

> diff --git a/login/tst-grantpt.c b/login/tst-grantpt.c

> index 1d7a220fcf..8ca901ef94 100644

> --- a/login/tst-grantpt.c

> +++ b/login/tst-grantpt.c

> @@ -1,4 +1,4 @@

> -/* Test for grantpt error corner cases.

> +/* Test for grantpt, unlockpt error corner cases.

>     Copyright (C) 2001-2020 Free Software Foundation, Inc.

>     This file is part of the GNU C Library.

>  

> @@ -28,7 +28,7 @@

>  #include <support/temp_file.h>

>  #include <support/xunistd.h>

>  

> -/* Test grantpt with a closed descriptor.  */

> +/* Test grantpt, unlockpt with a closed descriptor.  */

>  static void

>  test_ebadf (void)

>  {

> @@ -48,9 +48,12 @@ test_ebadf (void)

>        printf ("grantpt(): expected: return = %d, errno = %d\n", -1, EBADF);

>        printf ("           got: return = %d, errno = %d\n", ret, err);

>      }

> +

> +  TEST_COMPARE (unlockpt (fd), -1);

> +  TEST_COMPARE (errno, EBADF);

>  }


Ok.

>  

> -/* Test grantpt on a regular file.  */

> +/* Test grantpt, unlockpt on a regular file.  */

>  static void

>  test_einval (void)

>  {

> @@ -68,10 +71,13 @@ test_einval (void)

>        printf ("           got: return = %d, errno = %d\n", ret, err);

>      }

>  

> +  TEST_COMPARE (unlockpt (fd), -1);

> +  TEST_COMPARE (errno, EINVAL);

> +

>    xclose (fd);

>  }

>  


Ok.

> -/* Test grantpt on a non-ptmx pseudo-terminal.  */

> +/* Test grantpt, unlockpt on a non-ptmx pseudo-terminal.  */

>  static void

>  test_not_ptmx (void)

>  {

> @@ -80,6 +86,9 @@ test_not_ptmx (void)

>    TEST_COMPARE (grantpt (ptmx), 0);

>    TEST_COMPARE (unlockpt (ptmx), 0);

>  

> +  /* A second unlock succeeds as well.  */

> +  TEST_COMPARE (unlockpt (ptmx), 0);

> +

>    const char *name = ptsname (ptmx);

>    TEST_VERIFY_EXIT (name != NULL);

>    int pts = open (name, O_RDWR | O_NOCTTY);


Ok.

> @@ -88,6 +97,9 @@ test_not_ptmx (void)

>    TEST_COMPARE (grantpt (pts), -1);

>    TEST_COMPARE (errno, EINVAL);

>  

> +  TEST_COMPARE (unlockpt (pts), -1);

> +  TEST_COMPARE (errno, EINVAL);

> +

>    xclose (pts);

>    xclose (ptmx);

>  }


Ok.

> diff --git a/sysdeps/unix/sysv/linux/unlockpt.c b/sysdeps/unix/sysv/linux/unlockpt.c

> index 3a0ac7a96c..4d98abece0 100644

> --- a/sysdeps/unix/sysv/linux/unlockpt.c

> +++ b/sysdeps/unix/sysv/linux/unlockpt.c

> @@ -27,22 +27,11 @@

>  int

>  unlockpt (int fd)

>  {

> -#ifdef TIOCSPTLCK

> -  int save_errno = errno;

>    int unlock = 0;

>  

> -  if (__ioctl (fd, TIOCSPTLCK, &unlock))

> -    {

> -      if (errno == EINVAL)

> -	{

> -	  __set_errno (save_errno);

> -	  return 0;

> -	}

> -      else

> -	return -1;

> -    }

> -#endif

> -  /* If we have no TIOCSPTLCK ioctl, all slave pseudo terminals are

> -     unlocked by default.  */

> -  return 0;

> +  int ret = __ioctl (fd, TIOCSPTLCK, &unlock);

> +  if (ret != 0 && errno == ENOTTY)

> +    /* POSIX mandates EINVAL for non-ptmx descriptors.  */

> +    __set_errno (EINVAL);

> +  return ret;

>  }

> 


Ok.

Patch

diff --git a/login/tst-grantpt.c b/login/tst-grantpt.c
index 1d7a220fcf..8ca901ef94 100644
--- a/login/tst-grantpt.c
+++ b/login/tst-grantpt.c
@@ -1,4 +1,4 @@ 
-/* Test for grantpt error corner cases.
+/* Test for grantpt, unlockpt error corner cases.
    Copyright (C) 2001-2020 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
@@ -28,7 +28,7 @@ 
 #include <support/temp_file.h>
 #include <support/xunistd.h>
 
-/* Test grantpt with a closed descriptor.  */
+/* Test grantpt, unlockpt with a closed descriptor.  */
 static void
 test_ebadf (void)
 {
@@ -48,9 +48,12 @@  test_ebadf (void)
       printf ("grantpt(): expected: return = %d, errno = %d\n", -1, EBADF);
       printf ("           got: return = %d, errno = %d\n", ret, err);
     }
+
+  TEST_COMPARE (unlockpt (fd), -1);
+  TEST_COMPARE (errno, EBADF);
 }
 
-/* Test grantpt on a regular file.  */
+/* Test grantpt, unlockpt on a regular file.  */
 static void
 test_einval (void)
 {
@@ -68,10 +71,13 @@  test_einval (void)
       printf ("           got: return = %d, errno = %d\n", ret, err);
     }
 
+  TEST_COMPARE (unlockpt (fd), -1);
+  TEST_COMPARE (errno, EINVAL);
+
   xclose (fd);
 }
 
-/* Test grantpt on a non-ptmx pseudo-terminal.  */
+/* Test grantpt, unlockpt on a non-ptmx pseudo-terminal.  */
 static void
 test_not_ptmx (void)
 {
@@ -80,6 +86,9 @@  test_not_ptmx (void)
   TEST_COMPARE (grantpt (ptmx), 0);
   TEST_COMPARE (unlockpt (ptmx), 0);
 
+  /* A second unlock succeeds as well.  */
+  TEST_COMPARE (unlockpt (ptmx), 0);
+
   const char *name = ptsname (ptmx);
   TEST_VERIFY_EXIT (name != NULL);
   int pts = open (name, O_RDWR | O_NOCTTY);
@@ -88,6 +97,9 @@  test_not_ptmx (void)
   TEST_COMPARE (grantpt (pts), -1);
   TEST_COMPARE (errno, EINVAL);
 
+  TEST_COMPARE (unlockpt (pts), -1);
+  TEST_COMPARE (errno, EINVAL);
+
   xclose (pts);
   xclose (ptmx);
 }
diff --git a/sysdeps/unix/sysv/linux/unlockpt.c b/sysdeps/unix/sysv/linux/unlockpt.c
index 3a0ac7a96c..4d98abece0 100644
--- a/sysdeps/unix/sysv/linux/unlockpt.c
+++ b/sysdeps/unix/sysv/linux/unlockpt.c
@@ -27,22 +27,11 @@ 
 int
 unlockpt (int fd)
 {
-#ifdef TIOCSPTLCK
-  int save_errno = errno;
   int unlock = 0;
 
-  if (__ioctl (fd, TIOCSPTLCK, &unlock))
-    {
-      if (errno == EINVAL)
-	{
-	  __set_errno (save_errno);
-	  return 0;
-	}
-      else
-	return -1;
-    }
-#endif
-  /* If we have no TIOCSPTLCK ioctl, all slave pseudo terminals are
-     unlocked by default.  */
-  return 0;
+  int ret = __ioctl (fd, TIOCSPTLCK, &unlock);
+  if (ret != 0 && errno == ENOTTY)
+    /* POSIX mandates EINVAL for non-ptmx descriptors.  */
+    __set_errno (EINVAL);
+  return ret;
 }