1
2 /*--------------------------------------------------------------------*/
3 /*--- Client-space code for the core. vg_preloaded.c ---*/
4 /*--------------------------------------------------------------------*/
5
6 /*
7 This file is part of Valgrind, a dynamic binary instrumentation
8 framework.
9
10 Copyright (C) 2000-2013 Julian Seward
11 jseward@acm.org
12
13 This program is free software; you can redistribute it and/or
14 modify it under the terms of the GNU General Public License as
15 published by the Free Software Foundation; either version 2 of the
16 License, or (at your option) any later version.
17
18 This program is distributed in the hope that it will be useful, but
19 WITHOUT ANY WARRANTY; without even the implied warranty of
20 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
21 General Public License for more details.
22
23 You should have received a copy of the GNU General Public License
24 along with this program; if not, write to the Free Software
25 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
26 02111-1307, USA.
27
28 The GNU General Public License is contained in the file COPYING.
29 */
30
31
32 /* ---------------------------------------------------------------------
33 ALL THE CODE IN THIS FILE RUNS ON THE SIMULATED CPU.
34
35 These functions are not called directly - they're the targets of code
36 redirection or load notifications (see pub_core_redir.h for info).
37 They're named weirdly so that the intercept code can find them when the
38 shared object is initially loaded.
39
40 Note that this filename has the "vg_" prefix because it can appear
41 in stack traces, and the "vg_" makes it a little clearer that it
42 originates from Valgrind.
43 ------------------------------------------------------------------ */
44
45 #include "pub_core_basics.h"
46 #include "pub_core_clreq.h"
47 #include "pub_core_debuginfo.h" // Needed for pub_core_redir.h
48 #include "pub_core_redir.h" // For VG_NOTIFY_ON_LOAD
49
50 #if defined(VGO_linux)
51
52 /* ---------------------------------------------------------------------
53 Hook for running __libc_freeres once the program exits.
54 ------------------------------------------------------------------ */
55
56 void VG_NOTIFY_ON_LOAD(freeres)( void );
VG_NOTIFY_ON_LOAD(freeres)57 void VG_NOTIFY_ON_LOAD(freeres)( void )
58 {
59 # if !defined(__UCLIBC__) \
60 && !defined(VGPV_arm_linux_android) && !defined(VGPV_x86_linux_android) \
61 && !defined(VGPV_mips32_linux_android) && !defined(VGPV_arm64_linux_android)
62 extern void __libc_freeres(void);
63 __libc_freeres();
64 # endif
65 VALGRIND_DO_CLIENT_REQUEST_STMT(VG_USERREQ__LIBC_FREERES_DONE,
66 0, 0, 0, 0, 0);
67 /*NOTREACHED*/
68 *(volatile int *)0 = 'x';
69 }
70
71 /* ---------------------------------------------------------------------
72 Wrapper for indirect functions which need to be redirected.
73 ------------------------------------------------------------------ */
74
75 void * VG_NOTIFY_ON_LOAD(ifunc_wrapper) (void);
VG_NOTIFY_ON_LOAD(ifunc_wrapper)76 void * VG_NOTIFY_ON_LOAD(ifunc_wrapper) (void)
77 {
78 OrigFn fn;
79 Addr result = 0;
80
81 /* Call the original indirect function and get it's result */
82 VALGRIND_GET_ORIG_FN(fn);
83 CALL_FN_W_v(result, fn);
84
85 /* Ask the valgrind core running on the real CPU (as opposed to this
86 code which runs on the emulated CPU) to update the redirection that
87 led to this function. This client request eventually gives control to
88 the function VG_(redir_add_ifunc_target) in m_redir.c */
89 VALGRIND_DO_CLIENT_REQUEST_STMT(VG_USERREQ__ADD_IFUNC_TARGET,
90 fn.nraddr, result, 0, 0, 0);
91 return (void*)result;
92 }
93
94 #elif defined(VGO_darwin)
95
96 #include "config.h" /* VERSION */
97
98 /* ---------------------------------------------------------------------
99 Darwin crash log hints
100 ------------------------------------------------------------------ */
101
102 /* This string will be inserted into crash logs, so crashes while
103 running under Valgrind can be distinguished from other crashes. */
104 __private_extern__ const char *__crashreporter_info__ = "Instrumented by Valgrind " VERSION;
105
106 /* ---------------------------------------------------------------------
107 Darwin environment cleanup
108 ------------------------------------------------------------------ */
109
110 /* Scrubbing DYLD_INSERT_LIBRARIES from envp during exec is insufficient,
111 as there are other ways to launch a process with environment that
112 valgrind can't catch easily (i.e. launchd).
113 Instead, scrub DYLD_INSERT_LIBRARIES from the parent process once
114 dyld is done loading vg_preload.so.
115 */
116 #include <string.h>
117 #include <crt_externs.h>
118
119 // GrP fixme copied from m_libcproc
env_unsetenv(HChar ** env,const HChar * varname)120 static void env_unsetenv ( HChar **env, const HChar *varname )
121 {
122 HChar **from;
123 HChar **to = NULL;
124 Int len = strlen(varname);
125
126 for (from = to = env; from && *from; from++) {
127 if (!(strncmp(varname, *from, len) == 0 && (*from)[len] == '=')) {
128 *to = *from;
129 to++;
130 }
131 }
132 *(to++) = *(from++);
133 /* fix the 4th "char* apple" pointer (aka. executable path pointer) */
134 *(to++) = *(from++);
135 *to = NULL;
136 }
137
138 static void vg_cleanup_env(void) __attribute__((constructor));
vg_cleanup_env(void)139 static void vg_cleanup_env(void)
140 {
141 HChar **envp = (HChar**)*_NSGetEnviron();
142 env_unsetenv(envp, "VALGRIND_LAUNCHER");
143 env_unsetenv(envp, "DYLD_SHARED_REGION");
144 // GrP fixme should be more like mash_colon_env()
145 env_unsetenv(envp, "DYLD_INSERT_LIBRARIES");
146 }
147
148 /* ---------------------------------------------------------------------
149 Darwin arc4random (rdar://6166275)
150 ------------------------------------------------------------------ */
151
152 #include <fcntl.h>
153 #include <unistd.h>
154
155 int VG_REPLACE_FUNCTION_ZU(libSystemZdZaZddylib, arc4random)(void);
VG_REPLACE_FUNCTION_ZU(libSystemZdZaZddylib,arc4random)156 int VG_REPLACE_FUNCTION_ZU(libSystemZdZaZddylib, arc4random)(void)
157 {
158 static int rnd = -1;
159 int result;
160
161 if (rnd < 0) rnd = open("/dev/random", O_RDONLY);
162
163 read(rnd, &result, sizeof(result));
164 return result;
165 }
166
167 void VG_REPLACE_FUNCTION_ZU(libSystemZdZaZddylib, arc4random_stir)(void);
VG_REPLACE_FUNCTION_ZU(libSystemZdZaZddylib,arc4random_stir)168 void VG_REPLACE_FUNCTION_ZU(libSystemZdZaZddylib, arc4random_stir)(void)
169 {
170 // do nothing
171 }
172
173 void VG_REPLACE_FUNCTION_ZU(libSystemZdZaZddylib, arc4random_addrandom)(unsigned char *dat, int datlen);
VG_REPLACE_FUNCTION_ZU(libSystemZdZaZddylib,arc4random_addrandom)174 void VG_REPLACE_FUNCTION_ZU(libSystemZdZaZddylib, arc4random_addrandom)(unsigned char *dat, int datlen)
175 {
176 // do nothing
177 // GrP fixme ought to check [dat..dat+datlen) is defined
178 // but don't care if it's initialized
179 }
180
181 #else
182
183 # error Unknown OS
184 #endif
185
186 /*--------------------------------------------------------------------*/
187 /*--- end ---*/
188 /*--------------------------------------------------------------------*/
189