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
56void VG_NOTIFY_ON_LOAD(freeres)( void );
57void 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
75void * VG_NOTIFY_ON_LOAD(ifunc_wrapper) (void);
76void * 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
120static 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
138static void vg_cleanup_env(void)  __attribute__((constructor));
139static 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
155int VG_REPLACE_FUNCTION_ZU(libSystemZdZaZddylib, arc4random)(void);
156int 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
167void VG_REPLACE_FUNCTION_ZU(libSystemZdZaZddylib, arc4random_stir)(void);
168void VG_REPLACE_FUNCTION_ZU(libSystemZdZaZddylib, arc4random_stir)(void)
169{
170    // do nothing
171}
172
173void VG_REPLACE_FUNCTION_ZU(libSystemZdZaZddylib, arc4random_addrandom)(unsigned char *dat, int datlen);
174void 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