/*
- * Copyright (C) 2017 "IoT.bzh"
+ * Copyright (C) 2017, 2018 "IoT.bzh"
* Author José Bollo <jose.bollo@iot.bzh>
*
* Licensed under the Apache License, Version 2.0 (the "License");
#define _GNU_SOURCE
#include <stdlib.h>
+#include <stdio.h>
#include <signal.h>
#include <string.h>
#include <setjmp.h>
/* local handler */
static _Thread_local sigjmp_buf *error_handler;
+static _Thread_local int in_safe_dumpstack;
/* local timers */
static _Thread_local int thread_timer_set;
static _Thread_local timer_t thread_timerid;
+/* internal signal lists */
+static int sigerr[] = { SIG_FOR_TIMER, SIGSEGV, SIGFPE, SIGILL, SIGBUS, 0 };
+static int sigterm[] = { SIGINT, SIGABRT, SIGTERM, 0 };
+static int exiting = 0;
+static int enabled = 0;
+
/*
* Dumps the current stack
*/
-static void dumpstack(int crop)
+static void dumpstack(int crop, int signum)
{
- int idx, count;
- void *addresses[1000];
+ int idx, count, rc;
+ void *addresses[100];
char **locations;
+ char buffer[8000];
+ size_t pos, length;
count = backtrace(addresses, sizeof addresses / sizeof *addresses);
- locations = backtrace_symbols(addresses, count);
+ if (count <= crop)
+ crop = 0;
+ count -= crop;
+ locations = backtrace_symbols(&addresses[crop], count);
if (locations == NULL)
ERROR("can't get the backtrace (returned %d addresses)", count);
else {
- for (idx = crop; idx < count; idx++)
- ERROR("[BACKTRACE %d/%d] %s", idx - crop + 1, count - crop, locations[idx]);
+ length = sizeof buffer - 1;
+ pos = 0;
+ idx = 0;
+ while (pos < length && idx < count) {
+ rc = snprintf(&buffer[pos], length - pos, " [%d/%d] %s\n", idx + 1, count, locations[idx]);
+ pos += rc >= 0 ? rc : 0;
+ idx++;
+ }
+ buffer[length] = 0;
+ if (signum)
+ ERROR("BACKTRACE due to signal %s/%d:\n%s", strsignal(signum), signum, buffer);
+ else
+ ERROR("BACKTRACE:\n%s", buffer);
free(locations);
}
}
+static void safe_dumpstack_cb(int signum, void *closure)
+{
+ int *args = closure;
+ if (signum)
+ ERROR("Can't provide backtrace: raised signal %s", strsignal(signum));
+ else
+ dumpstack(args[0], args[1]);
+}
+
+static void safe_dumpstack(int crop, int signum)
+{
+ int args[2] = { crop + 3, signum };
+
+ in_safe_dumpstack = 1;
+ sig_monitor(0, safe_dumpstack_cb, args);
+ in_safe_dumpstack = 0;
+}
+
/*
* Creates a timer for the current thread
*
}
}
+/* install the handlers */
+static int install(void (*handler)(int), int *signals)
+{
+ int result = 1;
+ struct sigaction sa;
+
+ sa.sa_handler = handler;
+ sigemptyset(&sa.sa_mask);
+ sa.sa_flags = SA_NODEFER;
+ while(*signals > 0) {
+ if (sigaction(*signals, &sa, NULL) < 0) {
+ ERROR("failed to install signal handler for signal %s: %m", strsignal(*signals));
+ result = 0;
+ }
+ signals++;
+ }
+ return result;
+}
+
+/*
+ * rescue exit
+ */
+static void on_rescue_exit(int signum)
+{
+ ERROR("Rescue exit for signal %d: %s", signum, strsignal(signum));
+ _exit(exiting);
+}
+
+/*
+ * Do a safe exit
+ */
+static void safe_exit(int code)
+{
+ install(on_rescue_exit, sigerr);
+ install(on_rescue_exit, sigterm);
+ exiting = code;
+ exit(code);
+}
/* Handles signals that terminate the process */
static void on_signal_terminate (int signum)
{
- ERROR("Terminating signal %d received: %s", signum, strsignal(signum));
- if (signum == SIGABRT)
- dumpstack(3);
- exit(1);
+ if (!in_safe_dumpstack) {
+ ERROR("Terminating signal %d received: %s", signum, strsignal(signum));
+ if (signum == SIGABRT)
+ safe_dumpstack(3, signum);
+ }
+ safe_exit(1);
}
/* Handles monitored signals that can be continued */
static void on_signal_error(int signum)
{
- sigset_t sigset;
+ if (in_safe_dumpstack)
+ longjmp(*error_handler, signum);
ERROR("ALERT! signal %d received: %s", signum, strsignal(signum));
if (error_handler == NULL && signum == SIG_FOR_TIMER)
return;
- dumpstack(3);
+ safe_dumpstack(3, signum);
// unlock signal to allow a new signal to come
- if (error_handler != NULL) {
- sigemptyset(&sigset);
- sigaddset(&sigset, signum);
- sigprocmask(SIG_UNBLOCK, &sigset, 0);
+ if (error_handler != NULL)
longjmp(*error_handler, signum);
- }
+
ERROR("Unmonitored signal %d received: %s", signum, strsignal(signum));
- exit(2);
+ safe_exit(2);
}
-/* install the handlers */
-static int install(void (*handler)(int), int *signals)
+void sig_monitor_disable()
{
- int result = 1;
- while(*signals > 0) {
- if (signal(*signals, handler) == SIG_ERR) {
- ERROR("failed to install signal handler for signal %s", strsignal(*signals));
- result = 0;
- }
- signals++;
- }
- return result;
+ enabled = 0;
+ install(SIG_DFL, sigerr);
+ install(SIG_DFL, sigterm);
}
-int sig_monitor_init()
+int sig_monitor_enable()
{
- static int sigerr[] = { SIG_FOR_TIMER, SIGSEGV, SIGFPE, SIGILL, SIGBUS, 0 };
- static int sigterm[] = { SIGINT, SIGABRT, SIGTERM, 0 };
+ enabled = install(on_signal_error, sigerr) && install(on_signal_terminate, sigterm);
+ if (enabled)
+ return 0;
+ sig_monitor_disable();
+ return -1;
+}
- return (install(on_signal_error, sigerr) & install(on_signal_terminate, sigterm)) - 1;
+int sig_monitor_init(int enable)
+{
+ return enable ? sig_monitor_enable() : (sig_monitor_disable(), 0);
}
int sig_monitor_init_timeouts()
timeout_delete();
}
-void sig_monitor(int timeout, void (*function)(int sig, void*), void *arg)
+static void monitor(int timeout, void (*function)(int sig, void*), void *arg)
{
volatile int signum, signum2;
sigjmp_buf jmpbuf, *older;
signum = setjmp(jmpbuf);
if (signum == 0) {
error_handler = &jmpbuf;
- if (timeout)
+ if (timeout) {
+ timeout_create();
timeout_arm(timeout);
+ }
function(0, arg);
} else {
signum2 = setjmp(jmpbuf);
if (signum2 == 0)
function(signum, arg);
}
- error_handler = older;
if (timeout)
timeout_disarm();
+ error_handler = older;
}
-
+void sig_monitor(int timeout, void (*function)(int sig, void*), void *arg)
+{
+ if (enabled)
+ monitor(timeout, function, arg);
+ else
+ function(0, arg);
+}
Code Review / src / app-framework-binder.git / blobdiff