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-rw-r--r--src/global/signal_handler.cc665
1 files changed, 665 insertions, 0 deletions
diff --git a/src/global/signal_handler.cc b/src/global/signal_handler.cc
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+++ b/src/global/signal_handler.cc
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+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2011 New Dream Network
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software
+ * Foundation. See file COPYING.
+ *
+ */
+
+#include <sys/utsname.h>
+
+#include "include/compat.h"
+#include "pthread.h"
+
+#include "common/ceph_mutex.h"
+#include "common/BackTrace.h"
+#include "common/debug.h"
+#include "common/safe_io.h"
+#include "common/version.h"
+
+#include "include/uuid.h"
+#include "global/pidfile.h"
+#include "global/signal_handler.h"
+
+#include <poll.h>
+#include <signal.h>
+#include <sstream>
+#include <stdlib.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include "common/errno.h"
+#if defined(_AIX)
+extern char *sys_siglist[];
+#endif
+
+#define dout_context g_ceph_context
+
+void install_sighandler(int signum, signal_handler_t handler, int flags)
+{
+ int ret;
+ struct sigaction oldact;
+ struct sigaction act;
+ memset(&act, 0, sizeof(act));
+
+ act.sa_handler = handler;
+ sigemptyset(&act.sa_mask);
+ act.sa_flags = flags;
+
+ ret = sigaction(signum, &act, &oldact);
+ if (ret != 0) {
+ char buf[1024];
+#if defined(__sun)
+ char message[SIG2STR_MAX];
+ sig2str(signum,message);
+ snprintf(buf, sizeof(buf), "install_sighandler: sigaction returned "
+ "%d when trying to install a signal handler for %s\n",
+ ret, message);
+#else
+ snprintf(buf, sizeof(buf), "install_sighandler: sigaction returned "
+ "%d when trying to install a signal handler for %s\n",
+ ret, sig_str(signum));
+#endif
+ dout_emergency(buf);
+ exit(1);
+ }
+}
+
+void sighup_handler(int signum)
+{
+ g_ceph_context->reopen_logs();
+}
+
+static void reraise_fatal(int signum)
+{
+ // Use default handler to dump core
+ int ret = raise(signum);
+
+ // Normally, we won't get here. If we do, something is very weird.
+ char buf[1024];
+ if (ret) {
+ snprintf(buf, sizeof(buf), "reraise_fatal: failed to re-raise "
+ "signal %d\n", signum);
+ dout_emergency(buf);
+ }
+ else {
+ snprintf(buf, sizeof(buf), "reraise_fatal: default handler for "
+ "signal %d didn't terminate the process?\n", signum);
+ dout_emergency(buf);
+ }
+ exit(1);
+}
+
+
+// /etc/os-release looks like
+//
+// NAME=Fedora
+// VERSION="28 (Server Edition)"
+// ID=fedora
+// VERSION_ID=28
+//
+// or
+//
+// NAME="Ubuntu"
+// VERSION="16.04.3 LTS (Xenial Xerus)"
+// ID=ubuntu
+// ID_LIKE=debian
+//
+// get_from_os_release("FOO=bar\nTHIS=\"that\"\n", "FOO=", ...) will
+// write "bar\0" to out buffer, which is assumed to be as large as the input
+// file.
+static int parse_from_os_release(
+ const char *file, const char *key,
+ char *out)
+{
+ const char *p = strstr(file, key);
+ if (!p) {
+ return -1;
+ }
+ const char *start = p + strlen(key);
+ const char *end = strchr(start, '\n');
+ if (!end) {
+ return -1;
+ }
+ if (*start == '"' && *(end - 1) == '"') {
+ ++start;
+ --end;
+ }
+ if (start >= end) {
+ return -1;
+ }
+ memcpy(out, start, end - start);
+ out[end - start] = 0;
+ return 0;
+}
+
+static void handle_fatal_signal(int signum)
+{
+ // This code may itself trigger a SIGSEGV if the heap is corrupt. In that
+ // case, SA_RESETHAND specifies that the default signal handler--
+ // presumably dump core-- will handle it.
+ char buf[1024];
+ char pthread_name[16] = {0}; //limited by 16B include terminating null byte.
+ int r = ceph_pthread_getname(pthread_self(), pthread_name, sizeof(pthread_name));
+ (void)r;
+#if defined(__sun)
+ char message[SIG2STR_MAX];
+ sig2str(signum,message);
+ snprintf(buf, sizeof(buf), "*** Caught signal (%s) **\n "
+ "in thread %llx thread_name:%s\n", message, (unsigned long long)pthread_self(),
+ pthread_name);
+#else
+ snprintf(buf, sizeof(buf), "*** Caught signal (%s) **\n "
+ "in thread %llx thread_name:%s\n", sig_str(signum), (unsigned long long)pthread_self(),
+ pthread_name);
+#endif
+ dout_emergency(buf);
+ pidfile_remove();
+
+ // TODO: don't use an ostringstream here. It could call malloc(), which we
+ // don't want inside a signal handler.
+ // Also fix the backtrace code not to allocate memory.
+ BackTrace bt(1);
+ ostringstream oss;
+ bt.print(oss);
+ dout_emergency(oss.str());
+
+ char base[PATH_MAX] = { 0 };
+ if (g_ceph_context &&
+ g_ceph_context->_conf->crash_dir.size()) {
+ // -- crash dump --
+ // id
+ ostringstream idss;
+ utime_t now = ceph_clock_now();
+ now.gmtime(idss);
+ uuid_d uuid;
+ uuid.generate_random();
+ idss << "_" << uuid;
+ string id = idss.str();
+ std::replace(id.begin(), id.end(), ' ', '_');
+
+ snprintf(base, sizeof(base), "%s/%s",
+ g_ceph_context->_conf->crash_dir.c_str(),
+ id.c_str());
+ int r = ::mkdir(base, 0700);
+ if (r >= 0) {
+ char fn[PATH_MAX*2];
+ snprintf(fn, sizeof(fn)-1, "%s/meta", base);
+ int fd = ::open(fn, O_CREAT|O_WRONLY|O_CLOEXEC, 0600);
+ if (fd >= 0) {
+ JSONFormatter jf(true);
+ jf.open_object_section("crash");
+ jf.dump_string("crash_id", id);
+ now.gmtime(jf.dump_stream("timestamp"));
+ jf.dump_string("process_name", g_process_name);
+ jf.dump_string("entity_name", g_ceph_context->_conf->name.to_str());
+ jf.dump_string("ceph_version", ceph_version_to_str());
+
+ struct utsname u;
+ r = uname(&u);
+ if (r >= 0) {
+ jf.dump_string("utsname_hostname", u.nodename);
+ jf.dump_string("utsname_sysname", u.sysname);
+ jf.dump_string("utsname_release", u.release);
+ jf.dump_string("utsname_version", u.version);
+ jf.dump_string("utsname_machine", u.machine);
+ }
+#if defined(__linux__)
+ // os-release
+ int in = ::open("/etc/os-release", O_RDONLY|O_CLOEXEC);
+ if (in >= 0) {
+ char buf[4096];
+ r = safe_read(in, buf, sizeof(buf)-1);
+ if (r >= 0) {
+ buf[r] = 0;
+ char v[4096];
+ if (parse_from_os_release(buf, "NAME=", v) >= 0) {
+ jf.dump_string("os_name", v);
+ }
+ if (parse_from_os_release(buf, "ID=", v) >= 0) {
+ jf.dump_string("os_id", v);
+ }
+ if (parse_from_os_release(buf, "VERSION_ID=", v) >= 0) {
+ jf.dump_string("os_version_id", v);
+ }
+ if (parse_from_os_release(buf, "VERSION=", v) >= 0) {
+ jf.dump_string("os_version", v);
+ }
+ }
+ ::close(in);
+ }
+#endif
+
+ // assert?
+ if (g_assert_condition) {
+ jf.dump_string("assert_condition", g_assert_condition);
+ }
+ if (g_assert_func) {
+ jf.dump_string("assert_func", g_assert_func);
+ }
+ if (g_assert_file) {
+ jf.dump_string("assert_file", g_assert_file);
+ }
+ if (g_assert_line) {
+ jf.dump_unsigned("assert_line", g_assert_line);
+ }
+ if (g_assert_thread_name[0]) {
+ jf.dump_string("assert_thread_name", g_assert_thread_name);
+ }
+ if (g_assert_msg[0]) {
+ jf.dump_string("assert_msg", g_assert_msg);
+ }
+
+ // eio?
+ if (g_eio) {
+ jf.dump_bool("io_error", true);
+ if (g_eio_devname[0]) {
+ jf.dump_string("io_error_devname", g_eio_devname);
+ }
+ if (g_eio_path[0]) {
+ jf.dump_string("io_error_path", g_eio_path);
+ }
+ if (g_eio_error) {
+ jf.dump_int("io_error_code", g_eio_error);
+ }
+ if (g_eio_iotype) {
+ jf.dump_int("io_error_optype", g_eio_iotype);
+ }
+ if (g_eio_offset) {
+ jf.dump_unsigned("io_error_offset", g_eio_offset);
+ }
+ if (g_eio_length) {
+ jf.dump_unsigned("io_error_length", g_eio_length);
+ }
+ }
+
+ // backtrace
+ bt.dump(&jf);
+
+ jf.close_section();
+ ostringstream oss;
+ jf.flush(oss);
+ string s = oss.str();
+ r = safe_write(fd, s.c_str(), s.size());
+ (void)r;
+ ::close(fd);
+ }
+ snprintf(fn, sizeof(fn)-1, "%s/done", base);
+ ::creat(fn, 0444);
+ }
+ }
+
+ // avoid recursion back into logging code if that is where
+ // we got the SEGV.
+ if (g_ceph_context &&
+ g_ceph_context->_log &&
+ !g_ceph_context->_log->is_inside_log_lock()) {
+ // dump to log. this uses the heap extensively, but we're better
+ // off trying than not.
+ derr << buf << std::endl;
+ bt.print(*_dout);
+ *_dout << " NOTE: a copy of the executable, or `objdump -rdS <executable>` "
+ << "is needed to interpret this.\n"
+ << dendl;
+
+ g_ceph_context->_log->dump_recent();
+
+ if (base[0]) {
+ char fn[PATH_MAX*2];
+ snprintf(fn, sizeof(fn)-1, "%s/log", base);
+ g_ceph_context->_log->set_log_file(fn);
+ g_ceph_context->_log->reopen_log_file();
+ g_ceph_context->_log->dump_recent();
+ }
+ }
+
+ if (g_eio) {
+ // if this was an EIO crash, we don't need to trigger a core dump,
+ // since the problem is hardware, or some layer beneath us.
+ _exit(EIO);
+ } else {
+ reraise_fatal(signum);
+ }
+}
+
+void install_standard_sighandlers(void)
+{
+ install_sighandler(SIGSEGV, handle_fatal_signal, SA_RESETHAND | SA_NODEFER);
+ install_sighandler(SIGABRT, handle_fatal_signal, SA_RESETHAND | SA_NODEFER);
+ install_sighandler(SIGBUS, handle_fatal_signal, SA_RESETHAND | SA_NODEFER);
+ install_sighandler(SIGILL, handle_fatal_signal, SA_RESETHAND | SA_NODEFER);
+ install_sighandler(SIGFPE, handle_fatal_signal, SA_RESETHAND | SA_NODEFER);
+ install_sighandler(SIGXCPU, handle_fatal_signal, SA_RESETHAND | SA_NODEFER);
+ install_sighandler(SIGXFSZ, handle_fatal_signal, SA_RESETHAND | SA_NODEFER);
+ install_sighandler(SIGSYS, handle_fatal_signal, SA_RESETHAND | SA_NODEFER);
+}
+
+
+
+/// --- safe handler ---
+
+#include "common/Thread.h"
+#include <errno.h>
+
+#ifdef __APPLE__
+#include <libproc.h>
+
+string get_name_by_pid(pid_t pid)
+{
+ char buf[PROC_PIDPATHINFO_MAXSIZE];
+ int ret = proc_pidpath(pid, buf, sizeof(buf));
+ if (ret == 0) {
+ derr << "Fail to proc_pidpath(" << pid << ")"
+ << " error = " << cpp_strerror(ret)
+ << dendl;
+ return "<unknown>";
+ }
+ return string(buf, ret);
+}
+#else
+string get_name_by_pid(pid_t pid)
+{
+ // If the PID is 0, its means the sender is the Kernel itself
+ if (pid == 0) {
+ return "Kernel";
+ }
+ char proc_pid_path[PATH_MAX] = {0};
+ snprintf(proc_pid_path, PATH_MAX, PROCPREFIX "/proc/%d/cmdline", pid);
+ int fd = open(proc_pid_path, O_RDONLY);
+
+ if (fd < 0) {
+ fd = -errno;
+ derr << "Fail to open '" << proc_pid_path
+ << "' error = " << cpp_strerror(fd)
+ << dendl;
+ return "<unknown>";
+ }
+ // assuming the cmdline length does not exceed PATH_MAX. if it
+ // really does, it's fine to return a truncated version.
+ char buf[PATH_MAX] = {0};
+ int ret = read(fd, buf, sizeof(buf));
+ close(fd);
+ if (ret < 0) {
+ ret = -errno;
+ derr << "Fail to read '" << proc_pid_path
+ << "' error = " << cpp_strerror(ret)
+ << dendl;
+ return "<unknown>";
+ }
+ std::replace(buf, buf + ret, '\0', ' ');
+ return string(buf, ret);
+}
+#endif
+
+/**
+ * safe async signal handler / dispatcher
+ *
+ * This is an async unix signal handler based on the design from
+ *
+ * http://evbergen.home.xs4all.nl/unix-signals.html
+ *
+ * Features:
+ * - no unsafe work is done in the signal handler itself
+ * - callbacks are called from a regular thread
+ * - signals are not lost, unless multiple instances of the same signal
+ * are sent twice in quick succession.
+ */
+struct SignalHandler : public Thread {
+ /// to kick the thread, for shutdown, new handlers, etc.
+ int pipefd[2]; // write to [1], read from [0]
+
+ /// to signal shutdown
+ bool stop = false;
+
+ /// for an individual signal
+ struct safe_handler {
+
+ safe_handler() {
+ memset(pipefd, 0, sizeof(pipefd));
+ memset(&handler, 0, sizeof(handler));
+ memset(&info_t, 0, sizeof(info_t));
+ }
+
+ siginfo_t info_t;
+ int pipefd[2]; // write to [1], read from [0]
+ signal_handler_t handler;
+ };
+
+ /// all handlers
+ safe_handler *handlers[32] = {nullptr};
+
+ /// to protect the handlers array
+ ceph::mutex lock = ceph::make_mutex("SignalHandler::lock");
+
+ SignalHandler() {
+ // create signal pipe
+ int r = pipe_cloexec(pipefd);
+ ceph_assert(r == 0);
+ r = fcntl(pipefd[0], F_SETFL, O_NONBLOCK);
+ ceph_assert(r == 0);
+
+ // create thread
+ create("signal_handler");
+ }
+
+ ~SignalHandler() override {
+ shutdown();
+ }
+
+ void signal_thread() {
+ int r = write(pipefd[1], "\0", 1);
+ ceph_assert(r == 1);
+ }
+
+ void shutdown() {
+ stop = true;
+ signal_thread();
+ join();
+ }
+
+ // thread entry point
+ void *entry() override {
+ while (!stop) {
+ // build fd list
+ struct pollfd fds[33];
+
+ lock.lock();
+ int num_fds = 0;
+ fds[num_fds].fd = pipefd[0];
+ fds[num_fds].events = POLLIN | POLLERR;
+ fds[num_fds].revents = 0;
+ ++num_fds;
+ for (unsigned i=0; i<32; i++) {
+ if (handlers[i]) {
+ fds[num_fds].fd = handlers[i]->pipefd[0];
+ fds[num_fds].events = POLLIN | POLLERR;
+ fds[num_fds].revents = 0;
+ ++num_fds;
+ }
+ }
+ lock.unlock();
+
+ // wait for data on any of those pipes
+ int r = poll(fds, num_fds, -1);
+ if (stop)
+ break;
+ if (r > 0) {
+ char v;
+
+ // consume byte from signal socket, if any.
+ TEMP_FAILURE_RETRY(read(pipefd[0], &v, 1));
+
+ lock.lock();
+ for (unsigned signum=0; signum<32; signum++) {
+ if (handlers[signum]) {
+ r = read(handlers[signum]->pipefd[0], &v, 1);
+ if (r == 1) {
+ siginfo_t * siginfo = &handlers[signum]->info_t;
+ ostringstream message;
+ message << "received signal: " << sig_str(signum);
+ switch (siginfo->si_code) {
+ case SI_USER:
+ message << " from " << get_name_by_pid(siginfo->si_pid);
+ // If PID is undefined, it doesn't have a meaning to be displayed
+ if (siginfo->si_pid) {
+ message << " (PID: " << siginfo->si_pid << ")";
+ } else {
+ message << " ( Could be generated by pthread_kill(), raise(), abort(), alarm() )";
+ }
+ message << " UID: " << siginfo->si_uid;
+ break;
+ default:
+ /* As we have a not expected signal, let's report the structure to help debugging */
+ message << ", si_code : " << siginfo->si_code;
+ message << ", si_value (int): " << siginfo->si_value.sival_int;
+ message << ", si_value (ptr): " << siginfo->si_value.sival_ptr;
+ message << ", si_errno: " << siginfo->si_errno;
+ message << ", si_pid : " << siginfo->si_pid;
+ message << ", si_uid : " << siginfo->si_uid;
+ message << ", si_addr" << siginfo->si_addr;
+ message << ", si_status" << siginfo->si_status;
+ break;
+ }
+ derr << message.str() << dendl;
+ handlers[signum]->handler(signum);
+ }
+ }
+ }
+ lock.unlock();
+ }
+ }
+ return NULL;
+ }
+
+ void queue_signal(int signum) {
+ // If this signal handler is registered, the callback must be
+ // defined. We can do this without the lock because we will never
+ // have the signal handler defined without the handlers entry also
+ // being filled in.
+ ceph_assert(handlers[signum]);
+ int r = write(handlers[signum]->pipefd[1], " ", 1);
+ ceph_assert(r == 1);
+ }
+
+ void queue_signal_info(int signum, siginfo_t *siginfo, void * content) {
+ // If this signal handler is registered, the callback must be
+ // defined. We can do this without the lock because we will never
+ // have the signal handler defined without the handlers entry also
+ // being filled in.
+ ceph_assert(handlers[signum]);
+ memcpy(&handlers[signum]->info_t, siginfo, sizeof(siginfo_t));
+ int r = write(handlers[signum]->pipefd[1], " ", 1);
+ ceph_assert(r == 1);
+ }
+
+ void register_handler(int signum, signal_handler_t handler, bool oneshot);
+ void unregister_handler(int signum, signal_handler_t handler);
+};
+
+static SignalHandler *g_signal_handler = NULL;
+
+static void handler_signal_hook(int signum, siginfo_t * siginfo, void * content) {
+ g_signal_handler->queue_signal_info(signum, siginfo, content);
+}
+
+void SignalHandler::register_handler(int signum, signal_handler_t handler, bool oneshot)
+{
+ int r;
+
+ ceph_assert(signum >= 0 && signum < 32);
+
+ safe_handler *h = new safe_handler;
+
+ r = pipe_cloexec(h->pipefd);
+ ceph_assert(r == 0);
+ r = fcntl(h->pipefd[0], F_SETFL, O_NONBLOCK);
+ ceph_assert(r == 0);
+
+ h->handler = handler;
+ lock.lock();
+ handlers[signum] = h;
+ lock.unlock();
+
+ // signal thread so that it sees our new handler
+ signal_thread();
+
+ // install our handler
+ struct sigaction oldact;
+ struct sigaction act;
+ memset(&act, 0, sizeof(act));
+
+ act.sa_handler = (signal_handler_t)handler_signal_hook;
+ sigfillset(&act.sa_mask); // mask all signals in the handler
+ act.sa_flags = SA_SIGINFO | (oneshot ? SA_RESETHAND : 0);
+ int ret = sigaction(signum, &act, &oldact);
+ ceph_assert(ret == 0);
+}
+
+void SignalHandler::unregister_handler(int signum, signal_handler_t handler)
+{
+ ceph_assert(signum >= 0 && signum < 32);
+ safe_handler *h = handlers[signum];
+ ceph_assert(h);
+ ceph_assert(h->handler == handler);
+
+ // restore to default
+ signal(signum, SIG_DFL);
+
+ // _then_ remove our handlers entry
+ lock.lock();
+ handlers[signum] = NULL;
+ lock.unlock();
+
+ // this will wake up select() so that worker thread sees our handler is gone
+ close(h->pipefd[0]);
+ close(h->pipefd[1]);
+ delete h;
+}
+
+
+// -------
+
+void init_async_signal_handler()
+{
+ ceph_assert(!g_signal_handler);
+ g_signal_handler = new SignalHandler;
+}
+
+void shutdown_async_signal_handler()
+{
+ ceph_assert(g_signal_handler);
+ delete g_signal_handler;
+ g_signal_handler = NULL;
+}
+
+void queue_async_signal(int signum)
+{
+ ceph_assert(g_signal_handler);
+ g_signal_handler->queue_signal(signum);
+}
+
+void register_async_signal_handler(int signum, signal_handler_t handler)
+{
+ ceph_assert(g_signal_handler);
+ g_signal_handler->register_handler(signum, handler, false);
+}
+
+void register_async_signal_handler_oneshot(int signum, signal_handler_t handler)
+{
+ ceph_assert(g_signal_handler);
+ g_signal_handler->register_handler(signum, handler, true);
+}
+
+void unregister_async_signal_handler(int signum, signal_handler_t handler)
+{
+ ceph_assert(g_signal_handler);
+ g_signal_handler->unregister_handler(signum, handler);
+}
+
+
+
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