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) 1993-1996 Rick Sladkey <jrs@world.std.com>
5 * Copyright (c) 1996-1999 Wichert Akkerman <wichert@cistron.nl>
6 * Copyright (c) 2002-2004 Roland McGrath <roland@redhat.com>
7 * Copyright (c) 2010 Andreas Schwab <schwab@linux-m68k.org>
8 * Copyright (c) 2014-2015 Dmitry V. Levin <ldv@altlinux.org>
9 * Copyright (c) 2014-2018 The strace developers.
10 * All rights reserved.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 *    notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 *    notice, this list of conditions and the following disclaimer in the
19 *    documentation and/or other materials provided with the distribution.
20 * 3. The name of the author may not be used to endorse or promote products
21 *    derived from this software without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
24 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
25 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
26 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
27 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
28 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
29 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
30 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
32 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33 */
34
35#include "defs.h"
36
37#ifdef HAVE_STRUCT_USER_DESC
38
39# include <asm/ldt.h>
40
41# include "print_fields.h"
42# include "xstring.h"
43
44void
45print_user_desc(struct tcb *const tcp, const kernel_ulong_t addr,
46		enum user_desc_print_filter filter)
47{
48	struct user_desc desc;
49	unsigned *entry_number = get_tcb_priv_data(tcp);
50
51	switch (filter) {
52	case USER_DESC_ENTERING:
53		if (umove_or_printaddr(tcp, addr, &desc.entry_number))
54			return;
55
56		break;
57
58	case USER_DESC_EXITING:
59		if (!addr || !verbose(tcp))
60			return;
61		if (syserror(tcp) || umove(tcp, addr, &desc)) {
62			if (entry_number)
63				tprints(", ...}");
64
65			return;
66		}
67
68		break;
69
70	case USER_DESC_BOTH:
71		if (umove_or_printaddr(tcp, addr, &desc))
72			return;
73
74		break;
75	}
76
77	if (filter & USER_DESC_ENTERING) {
78		PRINT_FIELD_ID("{", desc, entry_number);
79
80		/*
81		 * If we don't print the whole structure now, let's save it for
82		 * later.
83		 */
84		if (filter == USER_DESC_ENTERING) {
85			entry_number = xmalloc(sizeof(*entry_number));
86
87			*entry_number = desc.entry_number;
88			set_tcb_priv_data(tcp, entry_number, free);
89		}
90	}
91
92	if (filter & USER_DESC_EXITING) {
93		/*
94		 * It should be the same in case of get_thread_area, but we can
95		 * never be sure...
96		 */
97		if (filter == USER_DESC_EXITING) {
98			if (entry_number) {
99				if (*entry_number != desc.entry_number) {
100					if ((int) desc.entry_number == -1)
101						tprints(" => -1");
102					else
103						tprintf(" => %u",
104							desc.entry_number);
105				}
106			} else {
107				/*
108				 * This is really strange. If we are here, it
109				 * means that we failed on entering but somehow
110				 * succeeded on exiting.
111				 */
112				PRINT_FIELD_ID(" => {", desc, entry_number);
113			}
114		}
115
116		PRINT_FIELD_0X(", ", desc, base_addr);
117		PRINT_FIELD_0X(", ", desc, limit);
118		PRINT_FIELD_U_CAST(", ", desc, seg_32bit, unsigned int);
119		PRINT_FIELD_U_CAST(", ", desc, contents, unsigned int);
120		PRINT_FIELD_U_CAST(", ", desc, read_exec_only, unsigned int);
121		PRINT_FIELD_U_CAST(", ", desc, limit_in_pages, unsigned int);
122		PRINT_FIELD_U_CAST(", ", desc, seg_not_present, unsigned int);
123		PRINT_FIELD_U_CAST(", ", desc, useable, unsigned int);
124
125# ifdef HAVE_STRUCT_USER_DESC_LM
126		/* lm is totally ignored for 32-bit processes */
127		if (current_klongsize == 8)
128			PRINT_FIELD_U_CAST(", ", desc, lm, unsigned int);
129# endif /* HAVE_STRUCT_USER_DESC_LM */
130
131		tprints("}");
132	}
133}
134
135SYS_FUNC(modify_ldt)
136{
137	if (entering(tcp)) {
138		tprintf("%d, ", (int) tcp->u_arg[0]);
139		if (tcp->u_arg[2] != sizeof(struct user_desc))
140			printaddr(tcp->u_arg[1]);
141		else
142			print_user_desc(tcp, tcp->u_arg[1], USER_DESC_BOTH);
143		tprintf(", %" PRI_klu, tcp->u_arg[2]);
144
145		return 0;
146	}
147
148	/*
149	 * For some reason ("tht ABI for sys_modify_ldt() expects
150	 * 'int'"), modify_ldt clips higher bits on x86_64.
151	 */
152
153	if (syserror(tcp) || (kernel_ulong_t) tcp->u_rval < 0xfffff000)
154		return 0;
155
156	tcp->u_error = -(unsigned int) tcp->u_rval;
157
158	return RVAL_PRINT_ERR_VAL;
159}
160
161SYS_FUNC(set_thread_area)
162{
163	if (entering(tcp)) {
164		print_user_desc(tcp, tcp->u_arg[0], USER_DESC_BOTH);
165	} else {
166		struct user_desc desc;
167
168		if (!verbose(tcp) || syserror(tcp) ||
169		    umove(tcp, tcp->u_arg[0], &desc) < 0) {
170			/* returned entry_number is not available */
171		} else {
172			static char outstr[32];
173
174			xsprintf(outstr, "entry_number=%u", desc.entry_number);
175			tcp->auxstr = outstr;
176			return RVAL_STR;
177		}
178	}
179	return 0;
180}
181
182SYS_FUNC(get_thread_area)
183{
184	print_user_desc(tcp, tcp->u_arg[0],
185			entering(tcp) ? USER_DESC_ENTERING : USER_DESC_EXITING);
186	return 0;
187}
188
189#endif /* HAVE_STRUCT_USER_DESC */
190
191#if defined(M68K) || defined(MIPS)
192SYS_FUNC(set_thread_area)
193{
194	printaddr(tcp->u_arg[0]);
195
196	return RVAL_DECODED;
197
198}
199#endif
200
201#if defined(M68K)
202SYS_FUNC(get_thread_area)
203{
204	return RVAL_DECODED | RVAL_HEX;
205}
206#endif
207