1 /*
2 * This file is part of ltrace.
3 * Copyright (C) 2010,2011,2012 Petr Machata, Red Hat Inc.
4 * Copyright (C) 2004,2008,2009 Juan Cespedes
5 * Copyright (C) 2006 Ian Wienand
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License as
9 * published by the Free Software Foundation; either version 2 of the
10 * License, or (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
20 * 02110-1301 USA
21 */
22
23 #include "config.h"
24
25 #include <sys/reg.h>
26 #include <sys/wait.h>
27 #include <assert.h>
28 #include <errno.h>
29 #include <stdlib.h>
30
31 #include "backend.h"
32 #include "debug.h"
33 #include "proc.h"
34 #include "ptrace.h"
35 #include "type.h"
36
37 #if (!defined(PTRACE_PEEKUSER) && defined(PTRACE_PEEKUSR))
38 # define PTRACE_PEEKUSER PTRACE_PEEKUSR
39 #endif
40
41 #if (!defined(PTRACE_POKEUSER) && defined(PTRACE_POKEUSR))
42 # define PTRACE_POKEUSER PTRACE_POKEUSR
43 #endif
44
45 #ifdef __x86_64__
46 # define ORIG_XAX (8 * ORIG_RAX)
47 #else
48 # define ORIG_XAX (4 * ORIG_EAX)
49 #endif
50
51 #ifdef __x86_64__
52 static const int x86_64 = 1;
53 #else
54 static const int x86_64 = 0;
55 #endif
56
57 void
get_arch_dep(struct process * proc)58 get_arch_dep(struct process *proc)
59 {
60 /* Unfortunately there are still remnants of mask_32bit uses
61 * around. */
62
63 if (proc->e_machine == EM_X86_64) {
64 proc->mask_32bit = 0;
65 proc->personality = 1;
66 } else if (x86_64) { /* x86_64/i386 */
67 proc->mask_32bit = 1;
68 proc->personality = 0;
69 } else {
70 proc->mask_32bit = 0;
71 proc->personality = 0;
72 }
73 }
74
75 /* Returns 1 if syscall, 2 if sysret, 0 otherwise.
76 */
77 int
syscall_p(struct process * proc,int status,int * sysnum)78 syscall_p(struct process *proc, int status, int *sysnum)
79 {
80 if (WIFSTOPPED(status)
81 && WSTOPSIG(status) == (SIGTRAP | proc->tracesysgood)) {
82 struct callstack_element *elem = NULL;
83 if (proc->callstack_depth > 0)
84 elem = proc->callstack + proc->callstack_depth - 1;
85
86 long int ret = ptrace(PTRACE_PEEKUSER, proc->pid, ORIG_XAX, 0);
87 if (ret == -1) {
88 if (errno)
89 return -1;
90 /* Otherwise, ORIG_RAX == -1 means that the
91 * system call should not be restarted. In
92 * that case rely on what we have on
93 * stack. */
94 if (elem != NULL && elem->is_syscall)
95 ret = elem->c_un.syscall;
96 }
97
98 *sysnum = ret;
99 debug(DEBUG_FUNCTION, "sysnum=%ld %p %d", ret,
100 get_instruction_pointer(proc), errno);
101 if (elem != NULL && elem->is_syscall
102 && elem->c_un.syscall == *sysnum)
103 return 2;
104
105 if (*sysnum >= 0)
106 return 1;
107 }
108 return 0;
109 }
110
111 size_t
arch_type_sizeof(struct process * proc,struct arg_type_info * info)112 arch_type_sizeof(struct process *proc, struct arg_type_info *info)
113 {
114 if (proc == NULL)
115 return (size_t)-2;
116
117 switch (info->type) {
118 case ARGTYPE_VOID:
119 return 0;
120
121 case ARGTYPE_CHAR:
122 return 1;
123
124 case ARGTYPE_SHORT:
125 case ARGTYPE_USHORT:
126 return 2;
127
128 case ARGTYPE_INT:
129 case ARGTYPE_UINT:
130 return 4;
131
132 case ARGTYPE_LONG:
133 case ARGTYPE_ULONG:
134 case ARGTYPE_POINTER:
135 return proc->e_machine == EM_X86_64 ? 8 : 4;
136
137 case ARGTYPE_FLOAT:
138 return 4;
139 case ARGTYPE_DOUBLE:
140 return 8;
141
142 case ARGTYPE_ARRAY:
143 case ARGTYPE_STRUCT:
144 /* Use default value. */
145 return (size_t)-2;
146
147 default:
148 assert(info->type != info->type);
149 abort();
150 }
151 }
152
153 size_t
arch_type_alignof(struct process * proc,struct arg_type_info * info)154 arch_type_alignof(struct process *proc, struct arg_type_info *info)
155 {
156 if (proc == NULL)
157 return (size_t)-2;
158
159 switch (info->type) {
160 default:
161 assert(info->type != info->type);
162 abort();
163 break;
164
165 case ARGTYPE_CHAR:
166 return 1;
167
168 case ARGTYPE_SHORT:
169 case ARGTYPE_USHORT:
170 return 2;
171
172 case ARGTYPE_INT:
173 case ARGTYPE_UINT:
174 return 4;
175
176 case ARGTYPE_LONG:
177 case ARGTYPE_ULONG:
178 case ARGTYPE_POINTER:
179 return proc->e_machine == EM_X86_64 ? 8 : 4;
180
181 case ARGTYPE_FLOAT:
182 return 4;
183 case ARGTYPE_DOUBLE:
184 return proc->e_machine == EM_X86_64 ? 8 : 4;
185
186 case ARGTYPE_ARRAY:
187 case ARGTYPE_STRUCT:
188 /* Use default value. */
189 return (size_t)-2;
190 }
191 }
192