Fix test-errno issues

This patch fixes multiple issues of test-errno.c (9a56f8718341):

  - Rename Linux test-errno.c to test-errno-linux.c to avoid build
    the same source for both tests.

  - Add a mlock check for 32 bits build running on 64 bits kernels.
    Althuough man pages states that mlock fails with EINVAL if final
    address overflows, kernels does not return it for aforementioned
    condition (it returns ENOMEM instead).  Although it seems to be
    a kernel issue for compat syscall handling, I think it is worth
    to still check syscall return and document the behavior.

  - Initialize option lenght for setsockopt check.

  - Change open test from EINVAL to EISDIR.

Checked on x86_64-linux-gnu and i686-linux-gnu (running on 64 bits
kernel).

	* posix/test-errno.c (do_test): Initialize setsockopt optlen.
	* sysdeps/unix/sysv/linux/test-errno.c: Move to ...
	* sysdeps/unix/sysv/linux/test-errno-linux.c: ... here.
	(test_wrp_rv): Fix format.
	(test_wrp_rv2): New macro.
	(do_test): Handle mlock return on 64 bits kernels with 32 bits
	binaries.

2 files changed, 41 insertions, 7 deletions

diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile
index 6b7aa3fdf8..1872cdb179 100644
--- a/sysdeps/unix/sysv/linux/Makefile
+++ b/sysdeps/unix/sysv/linux/Makefile
@@ -43,7 +43,7 @@ sysdep_headers += sys/mount.h sys/acct.h sys/sysctl.h \
 		  bits/mman-linux.h
 
 tests += tst-clone tst-clone2 tst-fanotify tst-personality tst-quota \
-	 tst-sync_file_range test-errno
+	 tst-sync_file_range test-errno-linux
 
 # Generate the list of SYS_* macros for the system calls (__NR_* macros).
 
diff --git a/sysdeps/unix/sysv/linux/test-errno.c b/sysdeps/unix/sysv/linux/test-errno-linux.c
index ab3735fe87..03a74bd6a1 100644
--- a/sysdeps/unix/sysv/linux/test-errno.c
+++ b/sysdeps/unix/sysv/linux/test-errno-linux.c
@@ -1,4 +1,5 @@
 /* Test that failing system calls do set errno to the correct value.
+   Linux sycalls version.
 
    Copyright (C) 2017 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
@@ -72,27 +73,55 @@
     rtype ret = syscall (__VA_ARGS__);				\
     int err = errno;						\
     int fail;							\
-    if (ret == (rtype) -1 && err == experr)			\
+    if ((ret == (rtype) -1) && (err == experr))			\
       fail = 0;							\
     else							\
       {								\
         fail = 1;						\
         if (ret != (rtype) -1)					\
           printf ("FAIL: " #syscall ": didn't fail as expected"	\
-               " (return "prtype")\n", ret);			\
+		  " (return "prtype")\n", ret);			\
         else if (err == 0xdead)					\
-          puts("FAIL: " #syscall ": didn't update errno\n");	\
+          puts ("FAIL: " #syscall ": didn't update errno");	\
         else if (err != experr)					\
           printf ("FAIL: " #syscall				\
-               ": errno is: %d (%s) expected: %d (%s)\n",	\
-               err, strerror (err), experr, strerror (experr));	\
+		  ": errno is: %d (%s) expected: %d (%s)\n",	\
+		  err, strerror (err), experr, strerror (experr));\
       }								\
     fail;							\
   }))
 
+#define test_wrp_rv2(rtype, prtype, experr1, experr2, syscall, ...) 	\
+  (__extension__ ({							\
+    errno = 0xdead;							\
+    rtype ret = syscall (__VA_ARGS__);					\
+    int err = errno;							\
+    int fail;								\
+    if ((ret == (rtype) -1) && ((err == experr1) || (err == experr2)))	\
+      fail = 0;								\
+    else								\
+      {									\
+        fail = 1;							\
+        if (ret != (rtype) -1)						\
+          printf ("FAIL: " #syscall ": didn't fail as expected"		\
+		  " (return "prtype")\n", ret);				\
+        else if (err == 0xdead)						\
+          puts ("FAIL: " #syscall ": didn't update errno");		\
+        else if (err != experr1 && err != experr2)			\
+          printf ("FAIL: " #syscall					\
+		  ": errno is: %d (%s) expected: %d (%s) or %d (%s)\n",	\
+		  err, strerror (err), experr1, strerror (experr1),	\
+		  experr2, strerror (experr2));				\
+      }									\
+    fail;								\
+  }))
+
 #define test_wrp(experr, syscall, ...)				\
   test_wrp_rv(int, "%d", experr, syscall, __VA_ARGS__)
 
+#define test_wrp2(experr1, experr2, syscall, ...)		\
+  test_wrp_rv2(int, "%d", experr1, experr2, syscall, __VA_ARGS__)
+
 static int
 do_test (void)
 {
@@ -120,7 +149,12 @@ do_test (void)
   fails |= test_wrp (ESRCH, getpgid, -1);
   fails |= test_wrp (EINVAL, inotify_add_watch, -1, "/", 0);
   fails |= test_wrp (EINVAL, mincore, (void *) -1, 0, vec);
-  fails |= test_wrp (EINVAL, mlock, (void *) -1, 1); // different errors
+  /* mlock fails if the result of the addition addr+len was less than addr
+     (which indicates final address overflow), however on 32 bits binaries
+     running on 64 bits kernels, internal syscall address check won't result
+     in an invalid address and thus syscalls fails later in vma
+     allocation.  */
+  fails |= test_wrp2 (EINVAL, ENOMEM, mlock, (void *) -1, 1);
   fails |= test_wrp (EINVAL, nanosleep, &ts, &ts);
   fails |= test_wrp (EINVAL, poll, &pollfd, -1, 0);
   fails |= test_wrp (ENODEV, quotactl, Q_GETINFO, NULL, -1, (caddr_t) &dqblk);