From d55fd7a5573ea7c7c14af95bc37618469cde8a5f Mon Sep 17 00:00:00 2001
From: "Ryan S. Arnold" <rsa@us.ibm.com>
Date: Thu, 17 Feb 2011 01:21:08 -0500
Subject: Fix INTERNAL_[V]SYSCALL_NCS macros to not cast return val to int.

---
 sysdeps/wordsize-64/Makefile     |   6 +++
 sysdeps/wordsize-64/tst-writev.c | 107 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 113 insertions(+)
 create mode 100644 sysdeps/wordsize-64/Makefile
 create mode 100644 sysdeps/wordsize-64/tst-writev.c

(limited to 'sysdeps/wordsize-64')

diff --git a/sysdeps/wordsize-64/Makefile b/sysdeps/wordsize-64/Makefile
new file mode 100644
index 0000000000..9903f51f9a
--- /dev/null
+++ b/sysdeps/wordsize-64/Makefile
@@ -0,0 +1,6 @@
+ifeq ($(subdir),misc)
+tests += tst-writev
+
+# Time enough for a large writev syscall to complete.
+tst-writev-ENV = TIMEOUTFACTOR="10"
+endif
diff --git a/sysdeps/wordsize-64/tst-writev.c b/sysdeps/wordsize-64/tst-writev.c
new file mode 100644
index 0000000000..6e4788612c
--- /dev/null
+++ b/sysdeps/wordsize-64/tst-writev.c
@@ -0,0 +1,107 @@
+/* Copyright (C) 2011 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ryan S. Arnold <rsa@us.ibm.com>, 2011.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <fcntl.h>
+#include <paths.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/uio.h>
+
+
+/* The purpose of this test is to verify that the INTERNAL_[V]SYSCALL_NCS
+   macros on 64-bit platforms don't cast the return type to (int) which would
+   erroneously sign extend the return value should the high bit of the bottom
+   half of the word be '1'.  */
+
+#if 0
+/* Used to test the non power-of-2 code path.  */
+#undef IOV_MAX
+#define IOV_MAX 1000
+#endif
+
+/* writev() should report that it has written EXPECTED number of bytes.  */
+#define EXPECTED ((size_t) INT32_MAX + 1)
+
+static int
+do_test (void)
+{
+  struct iovec iv[IOV_MAX];
+  /* POSIX doesn't guarantee that IOV_MAX is pow of 2 but we're optimistic.  */
+  size_t bufsz = EXPECTED / IOV_MAX;
+  size_t bufrem = EXPECTED % IOV_MAX;
+
+  /* If there's a remainder then IOV_MAX probably isn't a power of 2 and we
+     need to make bufsz bigger so that the last iovec, iv[IOV_MAX-1], is free
+     for the remainder.  */
+  if (bufrem)
+    {
+      bufsz = bufsz + 1;
+      bufrem = EXPECTED - (bufsz * (IOV_MAX - 1));
+    }
+
+  /* We writev to /dev/null since we're just testing writev's return value.  */
+  int fd = open (_PATH_DEVNULL, O_WRONLY);
+  if (fd == -1)
+    {
+      printf ("Unable to open /dev/null for writing.\n");
+      return -1;
+    }
+
+  iv[0].iov_base = malloc (bufsz);
+  if (iv[0].iov_base == NULL)
+    {
+      printf ("malloc (%zu) failed.\n", bufsz);
+      close (fd);
+      return -1;
+    }
+  iv[0].iov_len = bufsz;
+
+  /* We optimistically presume that there isn't a remainder and set all iovec
+     instances to the same base and len as the first instance.  */
+  for (int i = 1; i < IOV_MAX; i++)
+    {
+      /* We don't care what the data is so reuse the allocation from iv[0];  */
+      iv[i].iov_base = iv[0].iov_base;
+      iv[i].iov_len = iv[0].iov_len;
+    }
+
+  /* If there is a remainder then we correct the last iov_len.  */
+  if (bufrem)
+    iv[IOV_MAX - 1].iov_len = bufrem;
+
+  /* Write junk to /dev/null with the writev syscall in order to get a return
+     of INT32_MAX+1 bytes to verify that the INTERNAL_SYSCALL wrappers aren't
+     mangling the result if the signbit of a 32-bit number is set.  */
+  ssize_t ret = writev (fd, iv, IOV_MAX);
+
+  free (iv[0].iov_base);
+  close (fd);
+
+  if (ret != (ssize_t) EXPECTED)
+    {
+      printf ("writev() return value: %zd != EXPECTED: %zd\n", ret, EXPECTED);
+      return 1;
+    }
+
+  return 0;
+}
+
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"
-- 
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