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authorRyan S. Arnold <rsa@us.ibm.com>2011-02-17 01:21:08 -0500
committerUlrich Drepper <drepper@gmail.com>2011-02-17 01:21:08 -0500
commitd55fd7a5573ea7c7c14af95bc37618469cde8a5f (patch)
tree8bd8f3369e94c1c7ee75e7d8ee8458a94379a900 /sysdeps/wordsize-64
parentd4720230b54723c2b179030083318cffd6dbbc63 (diff)
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Fix INTERNAL_[V]SYSCALL_NCS macros to not cast return val to int.
Diffstat (limited to 'sysdeps/wordsize-64')
-rw-r--r--sysdeps/wordsize-64/Makefile6
-rw-r--r--sysdeps/wordsize-64/tst-writev.c107
2 files changed, 113 insertions, 0 deletions
diff --git a/sysdeps/wordsize-64/Makefile b/sysdeps/wordsize-64/Makefile
new file mode 100644
index 0000000..9903f51
--- /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 0000000..6e47886
--- /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"