blob: bf0506d0d982ca3eae185f061536ff6932b03144 [file] [log] [blame]
/* **********************************************************
* Copyright (c) 2012 Google, Inc. All rights reserved.
* **********************************************************/
/*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* * Neither the name of Google, Inc. nor the names of its contributors may be
* used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL GOOGLE, INC. OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
* DAMAGE.
*/
/* Helper exe that execs an exe with fake argv[0]. There isn't a way to do
* this from bash, so we need this helper.
*
* We use it for DR early injection by invoking it like so:
* drloader path/to/libdynamorio.so /path/to/app <args...>
*
* This way, the kernel puts the original path to the app on the stack as
* argv[0], and we don't have to shuffle the strings around to fix up
* /proc/pid/cmdline.
*
* XXX i#840: Eventually this should be folded into a drinject and drdeploy C
* implementation for Linux.
*/
#include "configure.h" /* for UNIX */
#include "globals_shared.h" /* for DYNAMORIO_VAR_EXE_PATH */
#include <errno.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/stat.h>
int
main(int argc, char **argv)
{
int r;
struct stat st;
char *libdr_so;
char *app;
if (argc < 3) {
fprintf(stderr, "Usage: %s <libdynamorio.so> <app path> [argv...]\n", argv[0]);
return -1;
}
/* Check if DR and the app exist. It's easier to give a good error message
* if we do this up front, rather than waiting for DR or execve to fail.
*/
libdr_so = argv[1];
r = stat(libdr_so, &st);
if (r < 0) {
fprintf(stderr, "%s: can't stat %s\n", argv[0], libdr_so);
perror(argv[0]);
return -1;
}
/* Check if the app exists. */
app = argv[2];
r = stat(app, &st);
if (r < 0) {
fprintf(stderr, "%s: can't stat %s\n", argv[0], app);
perror(argv[0]);
return -1;
}
/* The execve syscall prototype is:
* int execve(char *filename, char *argv[], char *envp[]);
* We pass libdr_so as the filename. For argv, we pass the rest of the
* command line starting with the app's path.
*/
setenv(DYNAMORIO_VAR_EXE_PATH, app, true /*overwrite*/);
r = execv(libdr_so, &argv[2]);
/* Only returns on error. */
fprintf(stderr, "%s: can't exec %s\n", argv[0], app);
perror(argv[0]);
return r;
}