]> granicus.if.org Git - strace/commitdiff
Fix decoding and dumping of readv syscall in case of short read
authorDmitry V. Levin <ldv@altlinux.org>
Wed, 20 Jan 2016 00:17:02 +0000 (00:17 +0000)
committerDmitry V. Levin <ldv@altlinux.org>
Wed, 20 Jan 2016 15:31:26 +0000 (15:31 +0000)
* defs.h (dumpiov_upto): New prototype.
(dumpiov): Change to a wrapper around dumpiov_upto.
* util.c (dumpiov): Rename to dumpiov_upto, add and check data_size
argument.
* io.c (SYS_FUNC(readv)): Call tprint_iov_upto instead
of tprint_iov and specify syscall return value as a data size limit.
* syscall.c (dumpio): In case of SEN_readv, call dumpiov_upto instead
of dumpiov and specify syscall return value as a data size limit.
* NEWS: Mention this fix.
* tests/readv.c: New file.
* tests/readv.test: New test.
* tests/Makefile.am (check_PROGRAMS): Add readv.
(TESTS): Add readv.test.
* tests/.gitignore: Add readv.

NEWS
defs.h
io.c
syscall.c
tests/.gitignore
tests/Makefile.am
tests/readv.c [new file with mode: 0644]
tests/readv.test [new file with mode: 0755]
util.c

diff --git a/NEWS b/NEWS
index 33fb3b08f3361acfa8204583672e2d8958cc654f..8b09bdae050d5ec34c0e5d761e32a655c2bc13a5 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -13,6 +13,7 @@ Noteworthy changes in release ?.?? (????-??-??)
   * Fixed decoding of mlock2 syscall on sparc.
   * Fixed decoding of syscalls unknown to the kernel on s390/s390x.
     (addresses Debian bug #485979 and Fedora bug #1298294).
+  * Fixed decoding and dumping of readv syscall in case of short read.
 
 Noteworthy changes in release 4.11 (2015-12-21)
 ===============================================
diff --git a/defs.h b/defs.h
index bae212c6eefd6fd92659e18ffd681847d5868435..47ca0c051985aabd8ce2e6db6b205ca6c78813cb 100644 (file)
--- a/defs.h
+++ b/defs.h
@@ -565,7 +565,9 @@ extern const char *sprintmode(int);
 extern const char *sprinttime(time_t);
 extern void dumpiov_in_msghdr(struct tcb *, long);
 extern void dumpiov_in_mmsghdr(struct tcb *, long);
-extern void dumpiov(struct tcb *, int, long);
+extern void dumpiov_upto(struct tcb *, int, long, unsigned long);
+#define dumpiov(tcp, len, addr) \
+       dumpiov_upto((tcp), (len), (addr), (unsigned long) -1L)
 extern void dumpstr(struct tcb *, long, int);
 extern void printstr(struct tcb *, long, long);
 extern bool printnum_short(struct tcb *, long, const char *)
diff --git a/io.c b/io.c
index 5ee967c1bbee1cfd8e7e2540820a156d8cbb8fa3..b98bc8a13c03bf5665b964662c0978dfef4687bf 100644 (file)
--- a/io.c
+++ b/io.c
@@ -123,7 +123,8 @@ SYS_FUNC(readv)
                printfd(tcp, tcp->u_arg[0]);
                tprints(", ");
        } else {
-               tprint_iov(tcp, tcp->u_arg[2], tcp->u_arg[1], 1);
+               tprint_iov_upto(tcp, tcp->u_arg[2], tcp->u_arg[1], 1,
+                               tcp->u_rval);
                tprintf(", %lu", tcp->u_arg[2]);
        }
        return 0;
index c5aceed440928feb63ec52329f3cbdd6d44f10bd..5f7b0edce647aaa0e62500d02afdc9c33ad1ad79 100644 (file)
--- a/syscall.c
+++ b/syscall.c
@@ -687,7 +687,8 @@ dumpio(struct tcb *tcp)
                        dumpstr(tcp, tcp->u_arg[1], tcp->u_rval);
                        return;
                case SEN_readv:
-                       dumpiov(tcp, tcp->u_arg[2], tcp->u_arg[1]);
+                       dumpiov_upto(tcp, tcp->u_arg[2], tcp->u_arg[1],
+                                    tcp->u_rval);
                        return;
                case SEN_recvmsg:
                        dumpiov_in_msghdr(tcp, tcp->u_arg[1]);
index 6188bddd632f4683a44b45ec9c469203401b1c63..6b62117ee7ecfb5350f704fe42989188a0e7c934 100644 (file)
@@ -67,6 +67,7 @@ pselect6
 readdir
 readlink
 readlinkat
+readv
 restart_syscall
 rt_sigqueueinfo
 sched_xetaffinity
index cf4e673b4eb6a8c08e0474d3c970a169ce17180e..d683a6bce847fc928569d7d139db0b8fd148b1a0 100644 (file)
@@ -113,6 +113,7 @@ check_PROGRAMS = \
        readdir \
        readlink \
        readlinkat \
+       readv \
        restart_syscall \
        rt_sigqueueinfo \
        sched_xetaffinity \
@@ -249,6 +250,7 @@ TESTS = \
        readdir.test \
        readlink.test \
        readlinkat.test \
+       readv.test \
        rt_sigqueueinfo.test \
        sched_xetaffinity.test \
        sched_xetattr.test \
diff --git a/tests/readv.c b/tests/readv.c
new file mode 100644 (file)
index 0000000..ec35c8a
--- /dev/null
@@ -0,0 +1,136 @@
+/*
+ * Check decoding of readv and writev 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"
+
+#include <assert.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/uio.h>
+
+int
+main(void)
+{
+       tprintf("%s", "");
+
+       int fds[2];
+       if (pipe(fds))
+               perror_msg_and_fail("pipe");
+       assert(0 == fds[0]);
+       assert(1 == fds[1]);
+
+       static const char w0_c[] = "012";
+       const char *w0_d = hexdump_strdup(w0_c);
+       void *w0 = tail_memdup(w0_c, 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));
+
+       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_));
+       const unsigned int w_len =
+               LENGTH_OF(w0_c) + LENGTH_OF(w1_c) + LENGTH_OF(w2_c);
+
+       assert(writev(1, w_iov, ARRAY_SIZE(w_iov_)) == (int) w_len);
+       close(1);
+       tprintf("writev(1, [{\"%s\", %u}, {\"%s\", %u}"
+               ", {\"%s\", %u}], %u) = %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_));
+
+       assert(readv(0, r_iov, ARRAY_SIZE(r0_iov_)) == (int) r_len);
+       tprintf("readv(0, [{\"%s\", %u}], %u) = %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_));
+
+       assert(readv(0, r_iov, ARRAY_SIZE(r1_iov_)) == (int) w_len - r_len);
+       tprintf("readv(0, [{\"%s\", %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_), w_len - r_len,
+               w_len - r_len, r1_d, r1_c);
+       close(0);
+
+       tprintf("+++ exited with 0 +++\n");
+       return 0;
+}
diff --git a/tests/readv.test b/tests/readv.test
new file mode 100755 (executable)
index 0000000..6a071e3
--- /dev/null
@@ -0,0 +1,13 @@
+#!/bin/sh
+
+# Check decoding of readv and writev syscalls.
+
+. "${srcdir=.}/init.sh"
+
+run_prog > /dev/null
+OUT="$LOG.out"
+run_strace -a30 -eread=0 -ewrite=1 -ereadv,writev $args > "$OUT"
+match_diff "$LOG" "$OUT"
+rm -f "$OUT"
+
+exit 0
diff --git a/util.c b/util.c
index e6985f88ab8b575d0c31b7dfe1525964080edf1b..01969a7f255eb7376e7bcdf0060437992efd79b9 100644 (file)
--- a/util.c
+++ b/util.c
@@ -841,7 +841,7 @@ printstr(struct tcb *tcp, long addr, long len)
 }
 
 void
-dumpiov(struct tcb *tcp, int len, long addr)
+dumpiov_upto(struct tcb *tcp, int len, long addr, unsigned long data_size)
 {
 #if SUPPORTED_PERSONALITIES > 1
        union {
@@ -873,12 +873,16 @@ dumpiov(struct tcb *tcp, int len, long addr)
        }
        if (umoven(tcp, addr, size, iov) >= 0) {
                for (i = 0; i < len; i++) {
+                       unsigned long iov_len = iov_iov_len(i);
+                       if (iov_len > data_size)
+                               iov_len = data_size;
+                       if (!iov_len)
+                               break;
+                       data_size -= iov_len;
                        /* include the buffer number to make it easy to
                         * match up the trace with the source */
-                       tprintf(" * %lu bytes in buffer %d\n",
-                               (unsigned long)iov_iov_len(i), i);
-                       dumpstr(tcp, (long) iov_iov_base(i),
-                               iov_iov_len(i));
+                       tprintf(" * %lu bytes in buffer %d\n", iov_len, i);
+                       dumpstr(tcp, (long) iov_iov_base(i), iov_len);
                }
        }
        free(iov);