Move lib/util from source4 to top-level libutil.

Conflicts:

	source4/Makefile

1 files changed, 226 insertions, 0 deletions

diff --git a/lib/util/fault.c b/lib/util/fault.c
new file mode 100644
index 0000000000..cb51cbd859
--- /dev/null
+++ b/lib/util/fault.c
@@ -0,0 +1,226 @@
+/* 
+   Unix SMB/CIFS implementation.
+   Critical Fault handling
+   Copyright (C) Andrew Tridgell 1992-1998
+   
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+   
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+   
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "includes.h"
+#include "version.h"
+#include "system/wait.h"
+#include "system/filesys.h"
+
+/**
+ * @file
+ * @brief Fault handling
+ */
+
+/* the registered fault handler */
+static struct {
+	const char *name;
+	void (*fault_handler)(int sig);
+} fault_handlers;
+
+static const char *progname;
+
+#ifdef HAVE_BACKTRACE
+#include <execinfo.h>
+#elif HAVE_LIBEXC_H
+#include <libexc.h>
+#endif
+
+/**
+ * Write backtrace to debug log
+ */
+_PUBLIC_ void call_backtrace(void)
+{
+#ifdef HAVE_BACKTRACE
+#ifndef BACKTRACE_STACK_SIZE
+#define BACKTRACE_STACK_SIZE 64
+#endif
+	void *backtrace_stack[BACKTRACE_STACK_SIZE];
+	size_t backtrace_size;
+	char **backtrace_strings;
+
+	/* get the backtrace (stack frames) */
+	backtrace_size = backtrace(backtrace_stack,BACKTRACE_STACK_SIZE);
+	backtrace_strings = backtrace_symbols(backtrace_stack, backtrace_size);
+
+	DEBUG(0, ("BACKTRACE: %lu stack frames:\n", 
+		  (unsigned long)backtrace_size));
+	
+	if (backtrace_strings) {
+		int i;
+
+		for (i = 0; i < backtrace_size; i++)
+			DEBUGADD(0, (" #%u %s\n", i, backtrace_strings[i]));
+
+		/* Leak the backtrace_strings, rather than risk what free() might do */
+	}
+
+#elif HAVE_LIBEXC
+
+#define NAMESIZE 32 /* Arbitrary */
+#ifndef BACKTRACE_STACK_SIZE
+#define BACKTRACE_STACK_SIZE 64
+#endif
+
+	/* The IRIX libexc library provides an API for unwinding the stack. See
+	 * libexc(3) for details. Apparantly trace_back_stack leaks memory, but
+	 * since we are about to abort anyway, it hardly matters.
+	 *
+	 * Note that if we paniced due to a SIGSEGV or SIGBUS (or similar) this
+	 * will fail with a nasty message upon failing to open the /proc entry.
+	 */
+	{
+		uint64_t	addrs[BACKTRACE_STACK_SIZE];
+		char *      	names[BACKTRACE_STACK_SIZE];
+		char		namebuf[BACKTRACE_STACK_SIZE * NAMESIZE];
+
+		int		i;
+		int		levels;
+
+		ZERO_ARRAY(addrs);
+		ZERO_ARRAY(names);
+		ZERO_ARRAY(namebuf);
+
+		for (i = 0; i < BACKTRACE_STACK_SIZE; i++) {
+			names[i] = namebuf + (i * NAMESIZE);
+		}
+
+		levels = trace_back_stack(0, addrs, names,
+				BACKTRACE_STACK_SIZE, NAMESIZE);
+
+		DEBUG(0, ("BACKTRACE: %d stack frames:\n", levels));
+		for (i = 0; i < levels; i++) {
+			DEBUGADD(0, (" #%d 0x%llx %s\n", i, addrs[i], names[i]));
+		}
+     }
+#undef NAMESIZE
+#endif
+}
+
+_PUBLIC_ const char *panic_action = NULL;
+
+/**
+ Something really nasty happened - panic !
+**/
+_PUBLIC_ _NORETURN_ void smb_panic(const char *why)
+{
+	int result;
+
+	if (panic_action && *panic_action) {
+		char pidstr[20];
+		char cmdstring[200];
+		safe_strcpy(cmdstring, panic_action, sizeof(cmdstring));
+		snprintf(pidstr, sizeof(pidstr), "%u", getpid());
+		all_string_sub(cmdstring, "%PID%", pidstr, sizeof(cmdstring));
+		if (progname) {
+			all_string_sub(cmdstring, "%PROG%", progname, sizeof(cmdstring));
+		}
+		DEBUG(0, ("smb_panic(): calling panic action [%s]\n", cmdstring));
+		result = system(cmdstring);
+
+		if (result == -1)
+			DEBUG(0, ("smb_panic(): fork failed in panic action: %s\n",
+				  strerror(errno)));
+		else
+			DEBUG(0, ("smb_panic(): action returned status %d\n",
+				  WEXITSTATUS(result)));
+	}
+	DEBUG(0,("PANIC: %s\n", why));
+
+	call_backtrace();
+
+#ifdef SIGABRT
+	CatchSignal(SIGABRT,SIGNAL_CAST SIG_DFL);
+#endif
+	abort();
+}
+
+/**
+report a fault
+**/
+_NORETURN_ static void fault_report(int sig)
+{
+	static int counter;
+	
+	if (counter) _exit(1);
+
+	DEBUG(0,("=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=\n"));
+	DEBUG(0,("INTERNAL ERROR: Signal %d in pid %d (%s)",sig,(int)getpid(),SAMBA_VERSION_STRING));
+	DEBUG(0,("\nPlease read the file BUGS.txt in the distribution\n"));
+	DEBUG(0,("=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=\n"));
+
+	smb_panic("internal error");
+
+	exit(1);
+}
+
+/**
+catch serious errors
+**/
+_NORETURN_ static void sig_fault(int sig)
+{
+	if (fault_handlers.fault_handler) {
+		/* we have a fault handler, call it. It may not return. */
+		fault_handlers.fault_handler(sig);
+	}
+	/* If it returns or doesn't exist, use regular reporter */
+	fault_report(sig);
+}
+
+/**
+setup our fault handlers
+**/
+_PUBLIC_ void fault_setup(const char *pname)
+{
+	if (progname == NULL) {
+		progname = pname;
+	}
+#ifdef SIGSEGV
+	CatchSignal(SIGSEGV,SIGNAL_CAST sig_fault);
+#endif
+#ifdef SIGBUS
+	CatchSignal(SIGBUS,SIGNAL_CAST sig_fault);
+#endif
+#ifdef SIGABRT
+	CatchSignal(SIGABRT,SIGNAL_CAST sig_fault);
+#endif
+#ifdef SIGFPE
+	CatchSignal(SIGFPE,SIGNAL_CAST sig_fault);
+#endif
+}
+
+/**
+  register a fault handler. 
+  Should only be called once in the execution of smbd.
+*/
+_PUBLIC_ bool register_fault_handler(const char *name, 
+				     void (*fault_handler)(int sig))
+{
+	if (fault_handlers.name != NULL) {
+		/* it's already registered! */
+		DEBUG(2,("fault handler '%s' already registered - failed '%s'\n", 
+			 fault_handlers.name, name));
+		return false;
+	}
+
+	fault_handlers.name = name;
+	fault_handlers.fault_handler = fault_handler;
+
+	DEBUG(2,("fault handler '%s' registered\n", name));
+	return true;
+}