| Index: tools/android/run_pie/run_pie.c
|
| diff --git a/tools/android/run_pie/run_pie.c b/tools/android/run_pie/run_pie.c
|
| new file mode 100644
|
| index 0000000000000000000000000000000000000000..ee1a622eb8fb58b343d561558e0b0d2e8d95cc27
|
| --- /dev/null
|
| +++ b/tools/android/run_pie/run_pie.c
|
| @@ -0,0 +1,68 @@
|
| +// Copyright 2014 The Chromium Authors. All rights reserved.
|
| +// Use of this source code is governed by a BSD-style license that can be
|
| +// found in the LICENSE file.
|
| +
|
| +#include <dlfcn.h>
|
| +#include <stdio.h>
|
| +#include <string.h>
|
| +#include <sys/prctl.h>
|
| +#include <unistd.h>
|
| +
|
| +// This is a wrapper to run position independent executables on Android ICS,
|
| +// where the linker doesn't support PIE. This requires the PIE binaries to be
|
| +// built with CFLAGS +=-fvisibility=default -fPIE, and LDFLAGS += -rdynamic -pie
|
| +// such that the main() symbol remains exported and can be dlsym-ed.
|
| +
|
| +#define ERR_PREFIX "[PIE Loader] "
|
| +
|
| +typedef int (*main_t)(int, char**);
|
| +
|
| +
|
| +int main(int argc, char** argv) {
|
| + if (argc < 2) {
|
| + printf("Usage: %s path_to_pie_executable [args]\n", argv[0]);
|
| + return -1;
|
| + }
|
| +
|
| + // Shift left the argv[]. argv is what /proc/PID/cmdline prints out. In turn
|
| + // cmdline is what Android "ps" prints out. In turn "ps" is what many scripts
|
| + // look for to decide which processes to kill / killall.
|
| + int i;
|
| + char* next_argv_start = argv[0];
|
| + for (i = 1; i < argc; ++i) {
|
| + const size_t argv_len = strlen(argv[i]) + 1;
|
| + memcpy(argv[i - 1], argv[i], argv_len);
|
| + next_argv_start += argv_len;
|
| + argv[i] = next_argv_start;
|
| + }
|
| + argv[argc - 1] = NULL; // The last argv must be a NULL ptr.
|
| +
|
| + // Set also the proc name accordingly (/proc/PID/comm).
|
| + prctl(PR_SET_NAME, (long) argv[0]);
|
| +
|
| + // dlopen should not fail, unless:
|
| + // - The target binary does not exists:
|
| + // - The dependent .so libs cannot be loaded.
|
| + // In both cases, just bail out with an explicit error message.
|
| + void* handle = dlopen(argv[0], RTLD_NOW);
|
| + if (handle == NULL) {
|
| + printf(ERR_PREFIX "dlopen() failed: %s.\n", dlerror());
|
| + return -1;
|
| + }
|
| +
|
| + main_t pie_main = (main_t) dlsym(handle, "main");
|
| + if (pie_main) {
|
| + return pie_main(argc - 1, argv);
|
| + }
|
| +
|
| + // If we reached this point dlsym failed, very likely because the target
|
| + // binary has not been compiled with the proper CFLAGS / LDFLAGS.
|
| + // At this point the most sensible thing to do is running that normally
|
| + // via exec and hope that the target binary wasn't a PIE.
|
| + execv(argv[0], argv);
|
| +
|
| + // exevc is supposed to never return, unless it fails.
|
| + printf(ERR_PREFIX "Both dlsym() and the execv() fallback failed.\n");
|
| + perror("execv");
|
| + return -1;
|
| +}
|
|
|