1 /*
2 * Copyright (c) 1991, 1992 Paul Kranenburg <pk@cs.few.eur.nl>
3 * Copyright (c) 1993 Branko Lankester <branko@hacktic.nl>
4 * Copyright (c) 1993, 1994, 1995, 1996 Rick Sladkey <jrs@world.std.com>
5 * Copyright (c) 1996-1999 Wichert Akkerman <wichert@cistron.nl>
6 * Copyright (c) 2005-2007 Roland McGrath <roland@redhat.com>
7 * Copyright (c) 2006-2007 Ulrich Drepper <drepper@redhat.com>
8 * Copyright (c) 2009-2013 Denys Vlasenko <dvlasenk@redhat.com>
9 * Copyright (c) 2005-2015 Dmitry V. Levin <ldv@altlinux.org>
10 * Copyright (c) 2014-2018 The strace developers.
11 * All rights reserved.
12 *
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
15 * are met:
16 * 1. Redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer.
18 * 2. Redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution.
21 * 3. The name of the author may not be used to endorse or promote products
22 * derived from this software without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
25 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
26 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
27 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
28 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
29 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
30 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
31 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
32 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
33 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34 */
35
36 #include "defs.h"
37 #include "xstring.h"
38
39 #include <asm/fcntl.h>
40
41 /* some libcs are guilty of messing up with O_ACCMODE */
42 #undef O_ACCMODE
43 #define O_ACCMODE 03
44
45 #ifdef O_LARGEFILE
46 # if O_LARGEFILE == 0 /* biarch platforms in 64-bit mode */
47 # undef O_LARGEFILE
48 # endif
49 #endif
50
51 #include "xlat/open_access_modes.h"
52 #include "xlat/open_mode_flags.h"
53
54 #ifndef AT_FDCWD
55 # define AT_FDCWD -100
56 #endif
57
58 /* The fd is an "int", so when decoding x86 on x86_64, we need to force sign
59 * extension to get the right value. We do this by declaring fd as int here.
60 */
61 void
print_dirfd(struct tcb * tcp,int fd)62 print_dirfd(struct tcb *tcp, int fd)
63 {
64 if (fd == AT_FDCWD)
65 tprints("AT_FDCWD, ");
66 else {
67 printfd(tcp, fd);
68 tprints(", ");
69 }
70 }
71
72 /*
73 * low bits of the open(2) flags define access mode,
74 * other bits are real flags.
75 */
76 const char *
sprint_open_modes(unsigned int flags)77 sprint_open_modes(unsigned int flags)
78 {
79 static char outstr[(1 + ARRAY_SIZE(open_mode_flags)) * sizeof("O_LARGEFILE")];
80 char *p;
81 char sep;
82 const char *str;
83 const struct xlat *x;
84
85 sep = ' ';
86 p = stpcpy(outstr, "flags");
87 str = xlookup(open_access_modes, flags & 3);
88 if (str) {
89 *p++ = sep;
90 p = stpcpy(p, str);
91 flags &= ~3;
92 if (!flags)
93 return outstr;
94 sep = '|';
95 }
96
97 for (x = open_mode_flags; x->str; x++) {
98 if ((flags & x->val) == x->val) {
99 *p++ = sep;
100 p = stpcpy(p, x->str);
101 flags &= ~x->val;
102 if (!flags)
103 return outstr;
104 sep = '|';
105 }
106 }
107 /* flags is still nonzero */
108 *p++ = sep;
109 p = xappendstr(outstr, p, "%#x", flags);
110 return outstr;
111 }
112
113 void
tprint_open_modes(unsigned int flags)114 tprint_open_modes(unsigned int flags)
115 {
116 tprints(sprint_open_modes(flags) + sizeof("flags"));
117 }
118
119 #ifdef O_TMPFILE
120 /* The kernel & C libraries often inline O_DIRECTORY. */
121 # define STRACE_O_TMPFILE (O_TMPFILE & ~O_DIRECTORY)
122 #else /* !O_TMPFILE */
123 # define STRACE_O_TMPFILE 0
124 #endif
125
126 static int
decode_open(struct tcb * tcp,int offset)127 decode_open(struct tcb *tcp, int offset)
128 {
129 printpath(tcp, tcp->u_arg[offset]);
130 tprints(", ");
131 /* flags */
132 tprint_open_modes(tcp->u_arg[offset + 1]);
133 if (tcp->u_arg[offset + 1] & (O_CREAT | STRACE_O_TMPFILE)) {
134 /* mode */
135 tprints(", ");
136 print_numeric_umode_t(tcp->u_arg[offset + 2]);
137 }
138
139 return RVAL_DECODED | RVAL_FD;
140 }
141
SYS_FUNC(open)142 SYS_FUNC(open)
143 {
144 return decode_open(tcp, 0);
145 }
146
SYS_FUNC(openat)147 SYS_FUNC(openat)
148 {
149 print_dirfd(tcp, tcp->u_arg[0]);
150 return decode_open(tcp, 1);
151 }
152
SYS_FUNC(creat)153 SYS_FUNC(creat)
154 {
155 printpath(tcp, tcp->u_arg[0]);
156 tprints(", ");
157 print_numeric_umode_t(tcp->u_arg[1]);
158
159 return RVAL_DECODED | RVAL_FD;
160 }
161