diff --git a/cmds/dumpstate/dumpstate.c b/cmds/dumpstate/dumpstate.c index f419a2bab..84f079d80 100644 --- a/cmds/dumpstate/dumpstate.c +++ b/cmds/dumpstate/dumpstate.c @@ -64,7 +64,8 @@ static void get_tombstone_fds(tombstone_data_t data[NUM_TOMBSTONES]) { time_t thirty_minutes_ago = time(NULL) - 60*30; for (size_t i = 0; i < NUM_TOMBSTONES; i++) { snprintf(data[i].name, sizeof(data[i].name), "%s%02zu", TOMBSTONE_FILE_PREFIX, i); - int fd = open(data[i].name, O_RDONLY | O_CLOEXEC | O_NOFOLLOW); + int fd = TEMP_FAILURE_RETRY(open(data[i].name, + O_RDONLY | O_CLOEXEC | O_NOFOLLOW | O_NONBLOCK)); struct stat st; if (fstat(fd, &st) == 0 && S_ISREG(st.st_mode) && (time_t) st.st_mtime >= thirty_minutes_ago) { @@ -184,7 +185,8 @@ static void dumpstate() { if (!anr_traces_path[0]) { printf("*** NO VM TRACES FILE DEFINED (dalvik.vm.stack-trace-file)\n\n"); } else { - int fd = open(anr_traces_path, O_RDONLY | O_CLOEXEC | O_NOFOLLOW); + int fd = TEMP_FAILURE_RETRY(open(anr_traces_path, + O_RDONLY | O_CLOEXEC | O_NOFOLLOW | O_NONBLOCK)); if (fd < 0) { printf("*** NO ANR VM TRACES FILE (%s): %s\n\n", anr_traces_path, strerror(errno)); } else { diff --git a/cmds/dumpstate/dumpstate.h b/cmds/dumpstate/dumpstate.h index 2be340b56..d17a677f7 100644 --- a/cmds/dumpstate/dumpstate.h +++ b/cmds/dumpstate/dumpstate.h @@ -31,7 +31,9 @@ typedef void (for_each_userid_func)(int); /* prints the contents of a file */ int dump_file(const char *title, const char *path); -/* prints the contents of the fd */ +/* prints the contents of the fd + * fd must have been opened with the flag O_NONBLOCK. + */ int dump_file_from_fd(const char *title, const char *path, int fd); /* forks a command and waits for it to finish -- terminate args with NULL */ diff --git a/cmds/dumpstate/utils.c b/cmds/dumpstate/utils.c index 7ad9cf001..27b9fb178 100644 --- a/cmds/dumpstate/utils.c +++ b/cmds/dumpstate/utils.c @@ -53,6 +53,12 @@ static const char* native_processes_to_dump[] = { NULL, }; +static uint64_t nanotime() { + struct timespec ts; + clock_gettime(CLOCK_MONOTONIC, &ts); + return (uint64_t)ts.tv_sec * NANOS_PER_SEC + ts.tv_nsec; +} + void for_each_userid(void (*func)(int), const char *header) { DIR *d; struct dirent *de; @@ -98,7 +104,7 @@ static void __for_each_pid(void (*helper)(int, const char *, void *), const char sprintf(cmdpath,"/proc/%d/cmdline", pid); memset(cmdline, 0, sizeof(cmdline)); - if ((fd = open(cmdpath, O_RDONLY)) < 0) { + if ((fd = TEMP_FAILURE_RETRY(open(cmdpath, O_RDONLY))) < 0) { strcpy(cmdline, "N/A"); } else { read(fd, cmdline, sizeof(cmdline) - 1); @@ -149,7 +155,7 @@ static void for_each_tid_helper(int pid, const char *cmdline, void *arg) { sprintf(commpath,"/proc/%d/comm", tid); memset(comm, 0, sizeof(comm)); - if ((fd = open(commpath, O_RDONLY)) < 0) { + if ((fd = TEMP_FAILURE_RETRY(open(commpath, O_RDONLY))) < 0) { strcpy(comm, "N/A"); } else { char *c; @@ -180,7 +186,7 @@ void show_wchan(int pid, int tid, const char *name) { memset(buffer, 0, sizeof(buffer)); sprintf(path, "/proc/%d/wchan", tid); - if ((fd = open(path, O_RDONLY)) < 0) { + if ((fd = TEMP_FAILURE_RETRY(open(path, O_RDONLY))) < 0) { printf("Failed to open '%s' (%s)\n", path, strerror(errno)); return; } @@ -250,22 +256,7 @@ void do_showmap(int pid, const char *name) { run_command(title, 10, SU_PATH, "root", "showmap", arg, NULL); } -/* prints the contents of a file */ -int dump_file(const char *title, const char *path) { - int fd = open(path, O_RDONLY); - if (fd < 0) { - int err = errno; - if (title) printf("------ %s (%s) ------\n", title, path); - printf("*** %s: %s\n", path, strerror(err)); - if (title) printf("\n"); - return -1; - } - return dump_file_from_fd(title, path, fd); -} - -int dump_file_from_fd(const char *title, const char *path, int fd) { - char buffer[32768]; - +static int _dump_file_from_fd(const char *title, const char *path, int fd) { if (title) printf("------ %s (%s", title, path); if (title) { @@ -279,26 +270,76 @@ int dump_file_from_fd(const char *title, const char *path, int fd) { printf(") ------\n"); } - int newline = 0; - for (;;) { - int ret = read(fd, buffer, sizeof(buffer)); - if (ret > 0) { - newline = (buffer[ret - 1] == '\n'); - ret = fwrite(buffer, ret, 1, stdout); + bool newline = false; + fd_set read_set; + struct timeval tm; + while (1) { + FD_ZERO(&read_set); + FD_SET(fd, &read_set); + /* Timeout if no data is read for 30 seconds. */ + tm.tv_sec = 30; + tm.tv_usec = 0; + uint64_t elapsed = nanotime(); + int ret = TEMP_FAILURE_RETRY(select(fd + 1, &read_set, NULL, NULL, &tm)); + if (ret == -1) { + printf("*** %s: select failed: %s\n", path, strerror(errno)); + newline = true; + break; + } else if (ret == 0) { + elapsed = nanotime() - elapsed; + printf("*** %s: Timed out after %.3fs\n", path, + (float) elapsed / NANOS_PER_SEC); + newline = true; + break; + } else { + char buffer[65536]; + ssize_t bytes_read = TEMP_FAILURE_RETRY(read(fd, buffer, sizeof(buffer))); + if (bytes_read > 0) { + fwrite(buffer, bytes_read, 1, stdout); + newline = (buffer[bytes_read-1] == '\n'); + } else { + if (bytes_read == -1) { + printf("*** %s: Failed to read from fd: %s", path, strerror(errno)); + newline = true; + } + break; + } } - if (ret <= 0) break; } - close(fd); + TEMP_FAILURE_RETRY(close(fd)); if (!newline) printf("\n"); if (title) printf("\n"); return 0; } -static int64_t nanotime() { - struct timespec ts; - clock_gettime(CLOCK_MONOTONIC, &ts); - return (int64_t)ts.tv_sec * NANOS_PER_SEC + ts.tv_nsec; +/* prints the contents of a file */ +int dump_file(const char *title, const char *path) { + int fd = TEMP_FAILURE_RETRY(open(path, O_RDONLY | O_NONBLOCK | O_CLOEXEC)); + if (fd < 0) { + int err = errno; + if (title) printf("------ %s (%s) ------\n", title, path); + printf("*** %s: %s\n", path, strerror(err)); + if (title) printf("\n"); + return -1; + } + return _dump_file_from_fd(title, path, fd); +} + +/* fd must have been opened with the flag O_NONBLOCK. With this flag set, + * it's possible to avoid issues where opening the file itself can get + * stuck. + */ +int dump_file_from_fd(const char *title, const char *path, int fd) { + int flags = fcntl(fd, F_GETFL); + if (flags == -1) { + printf("*** %s: failed to get flags on fd %d: %s\n", path, fd, strerror(errno)); + return -1; + } else if (!(flags & O_NONBLOCK)) { + printf("*** %s: fd must have O_NONBLOCK set.\n", path); + return -1; + } + return _dump_file_from_fd(title, path, fd); } bool waitpid_with_timeout(pid_t pid, int timeout_seconds, int* status) { @@ -348,7 +389,7 @@ bool waitpid_with_timeout(pid_t pid, int timeout_seconds, int* status) { /* forks a command and waits for it to finish */ int run_command(const char *title, int timeout_seconds, const char *command, ...) { fflush(stdout); - int64_t start = nanotime(); + uint64_t start = nanotime(); pid_t pid = fork(); /* handle error case */ @@ -550,7 +591,8 @@ const char *dump_traces() { } /* create a new, empty traces.txt file to receive stack dumps */ - int fd = open(traces_path, O_CREAT | O_WRONLY | O_TRUNC | O_NOFOLLOW, 0666); /* -rw-rw-rw- */ + int fd = TEMP_FAILURE_RETRY(open(traces_path, O_CREAT | O_WRONLY | O_TRUNC | O_NOFOLLOW, + 0666)); /* -rw-rw-rw- */ if (fd < 0) { fprintf(stderr, "%s: %s\n", traces_path, strerror(errno)); return NULL; @@ -600,7 +642,7 @@ const char *dump_traces() { if (!strncmp(data, "/system/bin/app_process", strlen("/system/bin/app_process"))) { /* skip zygote -- it won't dump its stack anyway */ snprintf(path, sizeof(path), "/proc/%d/cmdline", pid); - int cfd = open(path, O_RDONLY); + int cfd = TEMP_FAILURE_RETRY(open(path, O_RDONLY)); len = read(cfd, data, sizeof(data) - 1); close(cfd); if (len <= 0) { @@ -612,7 +654,7 @@ const char *dump_traces() { } ++dalvik_found; - int64_t start = nanotime(); + uint64_t start = nanotime(); if (kill(pid, SIGQUIT)) { fprintf(stderr, "kill(%d, SIGQUIT): %s\n", pid, strerror(errno)); continue; @@ -642,7 +684,7 @@ const char *dump_traces() { fprintf(stderr, "lseek: %s\n", strerror(errno)); } else { static uint16_t timeout_failures = 0; - int64_t start = nanotime(); + uint64_t start = nanotime(); /* If 3 backtrace dumps fail in a row, consider debuggerd dead. */ if (timeout_failures == 3) {