Implement dumping of preadv and pwritev syscalls

* syscall.c (dumpio): Add SEN_preadv and SEN_pwritev.
* NEWS: Mention this.
* tests/preadv-pwritev.c: New file.
* tests/preadv-pwritev.test: New test.
* tests/.gitignore: Add preadv-pwritev.
* tests/Makefile.am (check_PROGRAMS): Likewise.
(preadv_pwritev_CPPFLAGS): New variable.
(DECODER_TESTS): Add preadv-pwritev.

NEWS

@@ -11,7 +11,7 @@ Noteworthy changes in release ?.?? (????-??-??)
   * Implemented caching of netlink conversations to reduce amount of time
     spent in decoding socket details in -yy mode.
   * Implemented decoding of copy_file_range syscall.
-  * Implemented dumping of vmsplice syscall.
+  * Implemented dumping of preadv, pwritev, and vmsplice syscalls.
   * Updated lists of ioctl commands from Linux 4.5.
 
 * Bug fixes

syscall.c

@@ -685,6 +685,7 @@ dumpio(struct tcb *tcp)
 			dumpstr(tcp, tcp->u_arg[1], tcp->u_rval);
 			return;
 		case SEN_readv:
+		case SEN_preadv:
 			dumpiov_upto(tcp, tcp->u_arg[2], tcp->u_arg[1],
 				     tcp->u_rval);
 			return;
@@ -705,6 +706,7 @@ dumpio(struct tcb *tcp)
 			dumpstr(tcp, tcp->u_arg[1], tcp->u_arg[2]);
 			break;
 		case SEN_writev:
+		case SEN_pwritev:
 		case SEN_vmsplice:
 			dumpiov(tcp, tcp->u_arg[2], tcp->u_arg[1]);
 			break;

tests/.gitignore

@@ -90,6 +90,7 @@ pipe
 poll
 ppoll
 preadv
+preadv-pwritev
 pselect6
 pwritev
 readdir

tests/Makefile.am

@@ -139,6 +139,7 @@ check_PROGRAMS = \
 	poll \
 	ppoll \
 	preadv \
+	preadv-pwritev \
 	pselect6 \
 	pwritev \
 	readdir \
@@ -225,6 +226,7 @@ mq_LDADD = -lrt $(LDADD)
 newfstatat_CPPFLAGS = $(AM_CPPFLAGS) -D_FILE_OFFSET_BITS=64
 pc_LDADD = $(dl_LIBS) $(LDADD)
 preadv_CPPFLAGS = $(AM_CPPFLAGS) -D_FILE_OFFSET_BITS=64
+preadv_pwritev_CPPFLAGS = $(AM_CPPFLAGS) -D_FILE_OFFSET_BITS=64
 pwritev_CPPFLAGS = $(AM_CPPFLAGS) -D_FILE_OFFSET_BITS=64
 stat64_CPPFLAGS = $(AM_CPPFLAGS) -D_FILE_OFFSET_BITS=64
 statfs_CPPFLAGS = $(AM_CPPFLAGS) -D_FILE_OFFSET_BITS=64
@@ -315,6 +317,7 @@ DECODER_TESTS = \
 	poll.test \
 	ppoll.test \
 	preadv.test \
+	preadv-pwritev.test \
 	pselect6.test \
 	pwritev.test \
 	readdir.test \

tests/preadv-pwritev.c

@@ -0,0 +1,183 @@
+/*
+ * Check decoding of preadv and pwritev syscalls.
+ *
+ * Copyright (c) 2016 Dmitry V. Levin <ldv@altlinux.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "tests.h"
+
+#if defined HAVE_PREADV && defined HAVE_PWRITEV
+
+# include <fcntl.h>
+# include <stdio.h>
+# include <sys/uio.h>
+# include <unistd.h>
+
+int
+main(void)
+{
+	tprintf("%s", "");
+
+	static char tmp[] = "preadv-pwritev-tmpfile";
+	if (open(tmp, O_CREAT|O_RDONLY|O_TRUNC, 0600) != 0)
+		perror_msg_and_fail("creat: %s", tmp);
+	if (open(tmp, O_WRONLY) != 1)
+		perror_msg_and_fail("open: %s", tmp);
+	if (unlink(tmp))
+		perror_msg_and_fail("unlink: %s", tmp);
+
+	static const char w0_c[] = "012";
+	const char *w0_d = hexdump_strdup(w0_c);
+	void *w0 = tail_memdup(w0_c, LENGTH_OF(w0_c));
+
+	const void *efault = w0 + LENGTH_OF(w0_c);
+
+	static const char w1_c[] = "34567";
+	const char *w1_d = hexdump_strdup(w1_c);
+	void *w1 = tail_memdup(w1_c, LENGTH_OF(w1_c));
+
+	static const char w2_c[] = "89abcde";
+	const char *w2_d = hexdump_strdup(w2_c);
+	void *w2 = tail_memdup(w2_c, LENGTH_OF(w2_c));
+
+	long rc;
+
+	rc = pwritev(1, efault, 42, 0);
+	if (rc != -1)
+		perror_msg_and_fail("pwritev: expected -1, returned %ld", rc);
+	tprintf("pwritev(1, %p, 42, 0) = -1 EFAULT (%m)\n", efault);
+
+	rc = preadv(0, efault, 42, 0);
+	if (rc != -1)
+		perror_msg_and_fail("preadv: expected -1, returned %ld", rc);
+	tprintf("preadv(0, %p, 42, 0) = -1 EFAULT (%m)\n", efault);
+
+	static const char r0_c[] = "01234567";
+	const char *r0_d = hexdump_strdup(r0_c);
+	static const char r1_c[] = "89abcde";
+	const char *r1_d = hexdump_strdup(r1_c);
+
+	const struct iovec w_iov_[] = {
+		{
+			.iov_base = w0,
+			.iov_len = LENGTH_OF(w0_c)
+		}, {
+			.iov_base = w1,
+			.iov_len = LENGTH_OF(w1_c)
+		}, {
+			.iov_base = w2,
+			.iov_len = LENGTH_OF(w2_c)
+		}
+	};
+	const struct iovec *w_iov = tail_memdup(w_iov_, sizeof(w_iov_));
+
+	rc = pwritev(1, w_iov, 0, 0);
+	if (rc)
+		perror_msg_and_fail("preadv: expected 0, returned %ld", rc);
+	tprintf("pwritev(1, [], 0, 0) = 0\n");
+
+	rc = pwritev(1, w_iov + ARRAY_SIZE(w_iov_) - 1, 2, 0);
+	if (rc != -1)
+		perror_msg_and_fail("pwritev: expected -1 EFAULT, returned %ld",
+				    rc);
+	tprintf("pwritev(1, [{\"%s\", %u}, %p], 2, 0) = -1 EFAULT (%m)\n",
+		w2_c, LENGTH_OF(w2_c), w_iov + ARRAY_SIZE(w_iov_));
+
+	const unsigned int w_len =
+		LENGTH_OF(w0_c) + LENGTH_OF(w1_c) + LENGTH_OF(w2_c);
+
+	rc = pwritev(1, w_iov, ARRAY_SIZE(w_iov_), 0);
+	if (rc != (int) w_len)
+		perror_msg_and_fail("pwritev: expected %u, returned %ld",
+				    w_len, rc);
+	close(1);
+	tprintf("pwritev(1, [{\"%s\", %u}, {\"%s\", %u}"
+		", {\"%s\", %u}], %u, 0) = %u\n"
+		" * %u bytes in buffer 0\n"
+		" | 00000 %-49s  %-16s |\n"
+		" * %u bytes in buffer 1\n"
+		" | 00000 %-49s  %-16s |\n"
+		" * %u bytes in buffer 2\n"
+		" | 00000 %-49s  %-16s |\n",
+		w0_c, LENGTH_OF(w0_c), w1_c, LENGTH_OF(w1_c),
+		w2_c, LENGTH_OF(w2_c), ARRAY_SIZE(w_iov_), w_len,
+		LENGTH_OF(w0_c), w0_d, w0_c,
+		LENGTH_OF(w1_c), w1_d, w1_c, LENGTH_OF(w2_c), w2_d, w2_c);
+
+	const unsigned int r_len = (w_len + 1) / 2;
+	void *r0 = tail_alloc(r_len);
+	const struct iovec r0_iov_[] = {
+		{
+			.iov_base = r0,
+			.iov_len = r_len
+		}
+	};
+	const struct iovec *r_iov = tail_memdup(r0_iov_, sizeof(r0_iov_));
+
+	rc = preadv(0, r_iov, ARRAY_SIZE(r0_iov_), 0);
+	if (rc != (int) r_len)
+		perror_msg_and_fail("preadv: expected %u, returned %ld",
+				    r_len, rc);
+	tprintf("preadv(0, [{\"%s\", %u}], %u, 0) = %u\n"
+		" * %u bytes in buffer 0\n"
+		" | 00000 %-49s  %-16s |\n",
+		r0_c, r_len, ARRAY_SIZE(r0_iov_), r_len, r_len, r0_d, r0_c);
+
+	void *r1 = tail_alloc(r_len);
+	void *r2 = tail_alloc(w_len);
+	const struct iovec r1_iov_[] = {
+		{
+			.iov_base = r1,
+			.iov_len = r_len
+		},
+		{
+			.iov_base = r2,
+			.iov_len = w_len
+		}
+	};
+	r_iov = tail_memdup(r1_iov_, sizeof(r1_iov_));
+
+	rc = preadv(0, r_iov, ARRAY_SIZE(r1_iov_), r_len);
+	if (rc != (int) w_len - r_len)
+		perror_msg_and_fail("preadv: expected %d, returned %ld",
+				    (int) w_len - r_len, rc);
+	tprintf("preadv(0, [{\"%s\", %u}, {\"\", %u}], %u, %u) = %u\n"
+		" * %u bytes in buffer 0\n"
+		" | 00000 %-49s  %-16s |\n",
+		r1_c, r_len, w_len, ARRAY_SIZE(r1_iov_),
+		r_len, w_len - r_len,
+		w_len - r_len, r1_d, r1_c);
+	close(0);
+
+	tprintf("+++ exited with 0 +++\n");
+	return 0;
+}
+
+#else
+
+SKIP_MAIN_UNDEFINED("HAVE_PREADV && HAVE_PWRITEV")
+
+#endif

tests/preadv-pwritev.test

@@ -0,0 +1,6 @@
+#!/bin/sh
+
+# Check decoding and dumping of preadv and pwritev syscalls.
+
+. "${srcdir=.}/init.sh"
+run_strace_match_diff -a19 -eread=0 -ewrite=1 -e trace=preadv,pwritev