1 #include <elf.h> 2 #include <fcntl.h> 3 #include <stdio.h> 4 #include <stdlib.h> 5 #include <sys/stat.h> 6 #include <sys/types.h> 7 #include <unistd.h> 8 9 #include <string> 10 11 void usage(const char* me) { 12 static const char* usage_s = "Usage:\n" 13 " %s /system/bin/app_process <args>\n" 14 "or, better:\n" 15 " setprop wrap.<nicename> %s\n"; 16 fprintf(stderr, usage_s, me, me); 17 exit(1); 18 } 19 20 void env_prepend(const char* name, const char* value, const char* delim) { 21 const char* value_old = getenv(name); 22 std::string value_new = value; 23 if (value_old) { 24 value_new += delim; 25 value_new += value_old; 26 } 27 setenv(name, value_new.c_str(), 1); 28 } 29 30 bool elf_is_64bit(const char* path) { 31 int fd = open(path, O_RDONLY); 32 if (fd == -1) return false; 33 34 const size_t kBufSize = EI_CLASS + 1; 35 char buf[kBufSize]; 36 ssize_t sz = read(fd, buf, kBufSize); 37 if (sz != kBufSize) { 38 close(fd); 39 return false; 40 } 41 42 if (buf[EI_MAG0] != ELFMAG0 || buf[EI_MAG1] != ELFMAG1 || 43 buf[EI_MAG2] != ELFMAG2 || buf[EI_MAG3] != ELFMAG3) 44 return false; 45 46 bool is_64bit = buf[EI_CLASS] == ELFCLASS64; 47 close(fd); 48 return is_64bit; 49 } 50 51 int main(int argc, char** argv) { 52 if (argc < 2) { 53 usage(argv[0]); 54 } 55 char** args = new char*[argc]; 56 // If we are wrapping app_process, replace it with app_process_asan. 57 // TODO(eugenis): rewrite to <dirname>/asan/<basename>, if exists? 58 if (strcmp(argv[1], "/system/bin/app_process") == 0) { 59 args[0] = (char*)"/system/bin/asan/app_process"; 60 } else if (strcmp(argv[1], "/system/bin/app_process32") == 0) { 61 args[0] = (char*)"/system/bin/asan/app_process32"; 62 } else if (strcmp(argv[1], "/system/bin/app_process64") == 0) { 63 args[0] = (char*)"/system/bin/asan/app_process64"; 64 } else { 65 args[0] = argv[1]; 66 } 67 68 for (int i = 1; i < argc - 1; ++i) 69 args[i] = argv[i + 1]; 70 args[argc - 1] = 0; 71 72 if (elf_is_64bit(args[0])) { 73 env_prepend("LD_LIBRARY_PATH", "/system/lib64/asan:/system/lib64", ":"); 74 } else { 75 env_prepend("LD_LIBRARY_PATH", "/system/lib/asan:/system/lib", ":"); 76 } 77 env_prepend("ASAN_OPTIONS", "allow_user_segv_handler=1", ","); 78 79 printf("ASAN_OPTIONS: %s\n", getenv("ASAN_OPTIONS")); 80 printf("LD_LIBRARY_PATH: %s\n", getenv("LD_LIBRARY_PATH")); 81 for (int i = 0; i < argc - 1; ++i) 82 printf("argv[%d] = %s\n", i, args[i]); 83 84 execv(args[0], args); 85 } 86
