summaryrefslogtreecommitdiffstats
path: root/debuggerd/debuggerd.c
diff options
context:
space:
mode:
Diffstat (limited to 'debuggerd/debuggerd.c')
-rw-r--r--debuggerd/debuggerd.c539
1 files changed, 0 insertions, 539 deletions
diff --git a/debuggerd/debuggerd.c b/debuggerd/debuggerd.c
deleted file mode 100644
index 756f7bb..0000000
--- a/debuggerd/debuggerd.c
+++ /dev/null
@@ -1,539 +0,0 @@
-/* system/debuggerd/debuggerd.c
-**
-** Copyright 2006, The Android Open Source Project
-**
-** Licensed under the Apache License, Version 2.0 (the "License");
-** you may not use this file except in compliance with the License.
-** You may obtain a copy of the License at
-**
-** http://www.apache.org/licenses/LICENSE-2.0
-**
-** Unless required by applicable law or agreed to in writing, software
-** distributed under the License is distributed on an "AS IS" BASIS,
-** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-** See the License for the specific language governing permissions and
-** limitations under the License.
-*/
-
-#include <stdio.h>
-#include <errno.h>
-#include <signal.h>
-#include <pthread.h>
-#include <stdarg.h>
-#include <fcntl.h>
-#include <sys/types.h>
-#include <dirent.h>
-#include <time.h>
-
-#include <sys/ptrace.h>
-#include <sys/wait.h>
-#include <sys/exec_elf.h>
-#include <sys/stat.h>
-#include <sys/poll.h>
-
-#include <log/logd.h>
-#include <log/logger.h>
-
-#include <cutils/sockets.h>
-#include <cutils/properties.h>
-#include <cutils/debugger.h>
-
-#include <corkscrew/backtrace.h>
-
-#include <linux/input.h>
-
-#include <private/android_filesystem_config.h>
-
-#include "backtrace.h"
-#include "getevent.h"
-#include "tombstone.h"
-#include "utility.h"
-
-typedef struct {
- debugger_action_t action;
- pid_t pid, tid;
- uid_t uid, gid;
- uintptr_t abort_msg_address;
-} debugger_request_t;
-
-static int
-write_string(const char* file, const char* string)
-{
- int len;
- int fd;
- ssize_t amt;
- fd = open(file, O_RDWR);
- len = strlen(string);
- if (fd < 0)
- return -errno;
- amt = write(fd, string, len);
- close(fd);
- return amt >= 0 ? 0 : -errno;
-}
-
-static
-void init_debug_led(void)
-{
- // trout leds
- write_string("/sys/class/leds/red/brightness", "0");
- write_string("/sys/class/leds/green/brightness", "0");
- write_string("/sys/class/leds/blue/brightness", "0");
- write_string("/sys/class/leds/red/device/blink", "0");
- // sardine leds
- write_string("/sys/class/leds/left/cadence", "0,0");
-}
-
-static
-void enable_debug_led(void)
-{
- // trout leds
- write_string("/sys/class/leds/red/brightness", "255");
- // sardine leds
- write_string("/sys/class/leds/left/cadence", "1,0");
-}
-
-static
-void disable_debug_led(void)
-{
- // trout leds
- write_string("/sys/class/leds/red/brightness", "0");
- // sardine leds
- write_string("/sys/class/leds/left/cadence", "0,0");
-}
-
-static void wait_for_user_action(pid_t pid) {
- /* First log a helpful message */
- LOG( "********************************************************\n"
- "* Process %d has been suspended while crashing. To\n"
- "* attach gdbserver for a gdb connection on port 5039\n"
- "* and start gdbclient:\n"
- "*\n"
- "* gdbclient app_process :5039 %d\n"
- "*\n"
- "* Wait for gdb to start, then press HOME or VOLUME DOWN key\n"
- "* to let the process continue crashing.\n"
- "********************************************************\n",
- pid, pid);
-
- /* wait for HOME or VOLUME DOWN key */
- if (init_getevent() == 0) {
- int ms = 1200 / 10;
- int dit = 1;
- int dah = 3*dit;
- int _ = -dit;
- int ___ = 3*_;
- int _______ = 7*_;
- const signed char codes[] = {
- dit,_,dit,_,dit,___,dah,_,dah,_,dah,___,dit,_,dit,_,dit,_______
- };
- size_t s = 0;
- struct input_event e;
- bool done = false;
- init_debug_led();
- enable_debug_led();
- do {
- int timeout = abs((int)(codes[s])) * ms;
- int res = get_event(&e, timeout);
- if (res == 0) {
- if (e.type == EV_KEY
- && (e.code == KEY_HOME || e.code == KEY_VOLUMEDOWN)
- && e.value == 0) {
- done = true;
- }
- } else if (res == 1) {
- if (++s >= sizeof(codes)/sizeof(*codes))
- s = 0;
- if (codes[s] > 0) {
- enable_debug_led();
- } else {
- disable_debug_led();
- }
- }
- } while (!done);
- uninit_getevent();
- }
-
- /* don't forget to turn debug led off */
- disable_debug_led();
- LOG("debuggerd resuming process %d", pid);
-}
-
-static int get_process_info(pid_t tid, pid_t* out_pid, uid_t* out_uid, uid_t* out_gid) {
- char path[64];
- snprintf(path, sizeof(path), "/proc/%d/status", tid);
-
- FILE* fp = fopen(path, "r");
- if (!fp) {
- return -1;
- }
-
- int fields = 0;
- char line[1024];
- while (fgets(line, sizeof(line), fp)) {
- size_t len = strlen(line);
- if (len > 6 && !memcmp(line, "Tgid:\t", 6)) {
- *out_pid = atoi(line + 6);
- fields |= 1;
- } else if (len > 5 && !memcmp(line, "Uid:\t", 5)) {
- *out_uid = atoi(line + 5);
- fields |= 2;
- } else if (len > 5 && !memcmp(line, "Gid:\t", 5)) {
- *out_gid = atoi(line + 5);
- fields |= 4;
- }
- }
- fclose(fp);
- return fields == 7 ? 0 : -1;
-}
-
-static int read_request(int fd, debugger_request_t* out_request) {
- struct ucred cr;
- int len = sizeof(cr);
- int status = getsockopt(fd, SOL_SOCKET, SO_PEERCRED, &cr, &len);
- if (status != 0) {
- LOG("cannot get credentials\n");
- return -1;
- }
-
- XLOG("reading tid\n");
- fcntl(fd, F_SETFL, O_NONBLOCK);
-
- struct pollfd pollfds[1];
- pollfds[0].fd = fd;
- pollfds[0].events = POLLIN;
- pollfds[0].revents = 0;
- status = TEMP_FAILURE_RETRY(poll(pollfds, 1, 3000));
- if (status != 1) {
- LOG("timed out reading tid (from pid=%d uid=%d)\n", cr.pid, cr.uid);
- return -1;
- }
-
- debugger_msg_t msg;
- memset(&msg, 0, sizeof(msg));
- status = TEMP_FAILURE_RETRY(read(fd, &msg, sizeof(msg)));
- if (status < 0) {
- LOG("read failure? %s (pid=%d uid=%d)\n",
- strerror(errno), cr.pid, cr.uid);
- return -1;
- }
- if (status == sizeof(debugger_msg_t)) {
- XLOG("crash request of size %d abort_msg_address=%#08x\n", status, msg.abort_msg_address);
- } else {
- LOG("invalid crash request of size %d (from pid=%d uid=%d)\n",
- status, cr.pid, cr.uid);
- return -1;
- }
-
- out_request->action = msg.action;
- out_request->tid = msg.tid;
- out_request->pid = cr.pid;
- out_request->uid = cr.uid;
- out_request->gid = cr.gid;
- out_request->abort_msg_address = msg.abort_msg_address;
-
- if (msg.action == DEBUGGER_ACTION_CRASH) {
- /* Ensure that the tid reported by the crashing process is valid. */
- char buf[64];
- struct stat s;
- snprintf(buf, sizeof buf, "/proc/%d/task/%d", out_request->pid, out_request->tid);
- if(stat(buf, &s)) {
- LOG("tid %d does not exist in pid %d. ignoring debug request\n",
- out_request->tid, out_request->pid);
- return -1;
- }
- } else if (cr.uid == 0
- || (cr.uid == AID_SYSTEM && msg.action == DEBUGGER_ACTION_DUMP_BACKTRACE)) {
- /* Only root or system can ask us to attach to any process and dump it explicitly.
- * However, system is only allowed to collect backtraces but cannot dump tombstones. */
- status = get_process_info(out_request->tid, &out_request->pid,
- &out_request->uid, &out_request->gid);
- if (status < 0) {
- LOG("tid %d does not exist. ignoring explicit dump request\n",
- out_request->tid);
- return -1;
- }
- } else {
- /* No one else is allowed to dump arbitrary processes. */
- return -1;
- }
- return 0;
-}
-
-static bool should_attach_gdb(debugger_request_t* request) {
- if (request->action == DEBUGGER_ACTION_CRASH) {
- char value[PROPERTY_VALUE_MAX];
- property_get("debug.db.uid", value, "-1");
- int debug_uid = atoi(value);
- return debug_uid >= 0 && request->uid <= (uid_t)debug_uid;
- }
- return false;
-}
-
-static void handle_request(int fd) {
- XLOG("handle_request(%d)\n", fd);
-
- debugger_request_t request;
- memset(&request, 0, sizeof(request));
- int status = read_request(fd, &request);
- if (!status) {
- XLOG("BOOM: pid=%d uid=%d gid=%d tid=%d\n",
- request.pid, request.uid, request.gid, request.tid);
-
- /* At this point, the thread that made the request is blocked in
- * a read() call. If the thread has crashed, then this gives us
- * time to PTRACE_ATTACH to it before it has a chance to really fault.
- *
- * The PTRACE_ATTACH sends a SIGSTOP to the target process, but it
- * won't necessarily have stopped by the time ptrace() returns. (We
- * currently assume it does.) We write to the file descriptor to
- * ensure that it can run as soon as we call PTRACE_CONT below.
- * See details in bionic/libc/linker/debugger.c, in function
- * debugger_signal_handler().
- */
- if (ptrace(PTRACE_ATTACH, request.tid, 0, 0)) {
- LOG("ptrace attach failed: %s\n", strerror(errno));
- } else {
- bool detach_failed = false;
- bool attach_gdb = should_attach_gdb(&request);
- if (TEMP_FAILURE_RETRY(write(fd, "\0", 1)) != 1) {
- LOG("failed responding to client: %s\n", strerror(errno));
- } else {
- char* tombstone_path = NULL;
-
- if (request.action == DEBUGGER_ACTION_CRASH) {
- close(fd);
- fd = -1;
- }
-
- int total_sleep_time_usec = 0;
- for (;;) {
- int signal = wait_for_signal(request.tid, &total_sleep_time_usec);
- if (signal < 0) {
- break;
- }
-
- switch (signal) {
- case SIGSTOP:
- if (request.action == DEBUGGER_ACTION_DUMP_TOMBSTONE) {
- XLOG("stopped -- dumping to tombstone\n");
- tombstone_path = engrave_tombstone(request.pid, request.tid,
- signal, request.abort_msg_address, true, true, &detach_failed,
- &total_sleep_time_usec);
- } else if (request.action == DEBUGGER_ACTION_DUMP_BACKTRACE) {
- XLOG("stopped -- dumping to fd\n");
- dump_backtrace(fd, -1,
- request.pid, request.tid, &detach_failed,
- &total_sleep_time_usec);
- } else {
- XLOG("stopped -- continuing\n");
- status = ptrace(PTRACE_CONT, request.tid, 0, 0);
- if (status) {
- LOG("ptrace continue failed: %s\n", strerror(errno));
- }
- continue; /* loop again */
- }
- break;
-
- case SIGILL:
- case SIGABRT:
- case SIGBUS:
- case SIGFPE:
- case SIGSEGV:
- case SIGPIPE:
-#ifdef SIGSTKFLT
- case SIGSTKFLT:
-#endif
- {
- XLOG("stopped -- fatal signal\n");
- /*
- * Send a SIGSTOP to the process to make all of
- * the non-signaled threads stop moving. Without
- * this we get a lot of "ptrace detach failed:
- * No such process".
- */
- kill(request.pid, SIGSTOP);
- /* don't dump sibling threads when attaching to GDB because it
- * makes the process less reliable, apparently... */
- tombstone_path = engrave_tombstone(request.pid, request.tid,
- signal, request.abort_msg_address, !attach_gdb, false,
- &detach_failed, &total_sleep_time_usec);
- break;
- }
-
- default:
- XLOG("stopped -- unexpected signal\n");
- LOG("process stopped due to unexpected signal %d\n", signal);
- break;
- }
- break;
- }
-
- if (request.action == DEBUGGER_ACTION_DUMP_TOMBSTONE) {
- if (tombstone_path) {
- write(fd, tombstone_path, strlen(tombstone_path));
- }
- close(fd);
- fd = -1;
- }
- free(tombstone_path);
- }
-
- XLOG("detaching\n");
- if (attach_gdb) {
- /* stop the process so we can debug */
- kill(request.pid, SIGSTOP);
-
- /* detach so we can attach gdbserver */
- if (ptrace(PTRACE_DETACH, request.tid, 0, 0)) {
- LOG("ptrace detach from %d failed: %s\n", request.tid, strerror(errno));
- detach_failed = true;
- }
-
- /*
- * if debug.db.uid is set, its value indicates if we should wait
- * for user action for the crashing process.
- * in this case, we log a message and turn the debug LED on
- * waiting for a gdb connection (for instance)
- */
- wait_for_user_action(request.pid);
- } else {
- /* just detach */
- if (ptrace(PTRACE_DETACH, request.tid, 0, 0)) {
- LOG("ptrace detach from %d failed: %s\n", request.tid, strerror(errno));
- detach_failed = true;
- }
- }
-
- /* resume stopped process (so it can crash in peace). */
- kill(request.pid, SIGCONT);
-
- /* If we didn't successfully detach, we're still the parent, and the
- * actual parent won't receive a death notification via wait(2). At this point
- * there's not much we can do about that. */
- if (detach_failed) {
- LOG("debuggerd committing suicide to free the zombie!\n");
- kill(getpid(), SIGKILL);
- }
- }
-
- }
- if (fd >= 0) {
- close(fd);
- }
-}
-
-static int do_server() {
- int s;
- struct sigaction act;
- int logsocket = -1;
-
- /*
- * debuggerd crashes can't be reported to debuggerd. Reset all of the
- * crash handlers.
- */
- signal(SIGILL, SIG_DFL);
- signal(SIGABRT, SIG_DFL);
- signal(SIGBUS, SIG_DFL);
- signal(SIGFPE, SIG_DFL);
- signal(SIGSEGV, SIG_DFL);
-#ifdef SIGSTKFLT
- signal(SIGSTKFLT, SIG_DFL);
-#endif
-
- // Ignore failed writes to closed sockets
- signal(SIGPIPE, SIG_IGN);
-
- logsocket = socket_local_client("logd",
- ANDROID_SOCKET_NAMESPACE_ABSTRACT, SOCK_DGRAM);
- if(logsocket < 0) {
- logsocket = -1;
- } else {
- fcntl(logsocket, F_SETFD, FD_CLOEXEC);
- }
-
- act.sa_handler = SIG_DFL;
- sigemptyset(&act.sa_mask);
- sigaddset(&act.sa_mask,SIGCHLD);
- act.sa_flags = SA_NOCLDWAIT;
- sigaction(SIGCHLD, &act, 0);
-
- s = socket_local_server(DEBUGGER_SOCKET_NAME,
- ANDROID_SOCKET_NAMESPACE_ABSTRACT, SOCK_STREAM);
- if(s < 0) return 1;
- fcntl(s, F_SETFD, FD_CLOEXEC);
-
- LOG("debuggerd: " __DATE__ " " __TIME__ "\n");
-
- for(;;) {
- struct sockaddr addr;
- socklen_t alen;
- int fd;
-
- alen = sizeof(addr);
- XLOG("waiting for connection\n");
- fd = accept(s, &addr, &alen);
- if(fd < 0) {
- XLOG("accept failed: %s\n", strerror(errno));
- continue;
- }
-
- fcntl(fd, F_SETFD, FD_CLOEXEC);
-
- handle_request(fd);
- }
- return 0;
-}
-
-static int do_explicit_dump(pid_t tid, bool dump_backtrace) {
- fprintf(stdout, "Sending request to dump task %d.\n", tid);
-
- if (dump_backtrace) {
- fflush(stdout);
- if (dump_backtrace_to_file(tid, fileno(stdout)) < 0) {
- fputs("Error dumping backtrace.\n", stderr);
- return 1;
- }
- } else {
- char tombstone_path[PATH_MAX];
- if (dump_tombstone(tid, tombstone_path, sizeof(tombstone_path)) < 0) {
- fputs("Error dumping tombstone.\n", stderr);
- return 1;
- }
- fprintf(stderr, "Tombstone written to: %s\n", tombstone_path);
- }
- return 0;
-}
-
-static void usage() {
- fputs("Usage: -b [<tid>]\n"
- " -b dump backtrace to console, otherwise dump full tombstone file\n"
- "\n"
- "If tid specified, sends a request to debuggerd to dump that task.\n"
- "Otherwise, starts the debuggerd server.\n", stderr);
-}
-
-int main(int argc, char** argv) {
- if (argc == 1) {
- return do_server();
- }
-
- bool dump_backtrace = false;
- bool have_tid = false;
- pid_t tid = 0;
- for (int i = 1; i < argc; i++) {
- if (!strcmp(argv[i], "-b")) {
- dump_backtrace = true;
- } else if (!have_tid) {
- tid = atoi(argv[i]);
- have_tid = true;
- } else {
- usage();
- return 1;
- }
- }
- if (!have_tid) {
- usage();
- return 1;
- }
- return do_explicit_dump(tid, dump_backtrace);
-}
generated by cgit v1.1 at 2025-08-16 06:26:58 +0000