[rsync/rsync-patches.git] / catch_crash_signals.diff

Igor Yu. Zhbanov wrote:
> I am using rsync compiled with Cygwin on windows. 
> I must call rsync from the *.bat script (I don't want to use a bash on Windows)
> and I have noticed that in the case when program compiled by Cygwin crashes
> via segmentation fault and default SIGSEGV handler is called, then it
> terminates process with exit status 0 as I see it from my *.bat script.
> (But if I invoke a program from bash (compiled with Cygwin too) I will see
> error code 139 as expected.)
> 
> It is a Cygwin's problem, not an rsync's, but to use it on windows and
> to distinguish situations when rsync crashes and when it exits normally,
> I have written signal handler which terminates process with code 50.
> You may use conventional 139. Also signal handler writes corresponding
> message to log file.
> 
> By the way. When I terminate rsync in daemon mode by pressing Control-C,
> it writes an error to log. May be this is not an error but info or notice?

I'm not sure I like this, but if you run into the cygwin problem, this might
prove helpful.

To use this patch, run these commands for a successful build:

    patch -p1 <patches/catch_crash_signals.diff
    ./configure                                  (optional if already run)
    make

--- old/errcode.h
+++ new/errcode.h
@@ -47,6 +47,8 @@
 
 #define RERR_TIMEOUT    30      /* timeout in data send/receive */
 
+#define RERR_WECRASHED	 50      /* We have crashed. */
+
 /* Although it doesn't seem to be specified anywhere,
  * ssh and the shell seem to return these values:
  *
--- old/log.c
+++ new/log.c
@@ -79,6 +79,7 @@ struct {
 	{ RERR_TERMINATED , "sibling process terminated abnormally" },
 	{ RERR_SIGNAL1    , "received SIGUSR1" },
 	{ RERR_SIGNAL     , "received SIGINT, SIGTERM, or SIGHUP" },
+	{ RERR_WECRASHED  , "rsync caught a CRASH-causing signal" },
 	{ RERR_WAITCHILD  , "waitpid() failed" },
 	{ RERR_MALLOC     , "error allocating core memory buffers" },
 	{ RERR_PARTIAL    , "some files could not be transferred" },
--- old/main.c
+++ new/main.c
@@ -155,8 +155,11 @@ static void wait_process_with_flush(pid_
 			*exit_code_ptr = RERR_TERMINATED;
 		else
 			*exit_code_ptr = RERR_WAITCHILD;
-	} else
+	} else {
 		*exit_code_ptr = WEXITSTATUS(status);
+		if (*exit_code_ptr == RERR_WECRASHED)
+			*exit_code_ptr = RERR_CRASHED;
+	}
 }
 
 /* This function gets called from all 3 processes.  We want the client side
@@ -1234,6 +1237,14 @@ RETSIGTYPE remember_children(UNUSED(int 
 				break;
 			}
 		}
+		if (WIFSIGNALED(status)) {
+			rprintf(FLOG,
+				"rsync error: (1) Child proccess has unexpectedly died with signal %d\n",
+				WTERMSIG(status));
+		} else if (WIFEXITED(status) && WEXITSTATUS(status) == RERR_WECRASHED) {
+			rprintf(FLOG,
+				"rsync error: (1) Child proccess has CRASHED.\n");
+		}
 	}
 #endif
 #ifndef HAVE_SIGACTION
@@ -1292,6 +1303,12 @@ static RETSIGTYPE rsync_panic_handler(UN
 }
 #endif
 
+static RETSIGTYPE rsync_crash_handler(UNUSED(int whatsig))
+{
+	log_exit(RERR_WECRASHED, __FILE__, __LINE__);
+	logfile_close();
+	_exit(RERR_WECRASHED);
+}
 
 int main(int argc,char *argv[])
 {
@@ -1314,6 +1331,11 @@ int main(int argc,char *argv[])
 	SIGACTMASK(SIGFPE, rsync_panic_handler);
 	SIGACTMASK(SIGABRT, rsync_panic_handler);
 	SIGACTMASK(SIGBUS, rsync_panic_handler);
+#else
+	SIGACTMASK(SIGSEGV, rsync_crash_handler);
+	SIGACTMASK(SIGFPE, rsync_crash_handler);
+	SIGACTMASK(SIGABRT, rsync_crash_handler);
+	SIGACTMASK(SIGBUS, rsync_crash_handler);
 #endif
 
 	starttime = time(NULL);
--- old/socket.c
+++ new/socket.c
@@ -454,7 +454,17 @@ int is_a_socket(int fd)
 static RETSIGTYPE sigchld_handler(UNUSED(int val))
 {
 #ifdef WNOHANG
-	while (waitpid(-1, NULL, WNOHANG) > 0) {}
+	int status;
+	while (waitpid(-1, &status, WNOHANG) > 0) {
+		if (WIFSIGNALED(status)) {
+			rprintf(FLOG,
+				"rsync error: (3) Child proccess has unexpectedly died with signal %d\n",
+				WTERMSIG(status));
+		} else if (WIFEXITED(status) && WEXITSTATUS(status) == RERR_WECRASHED) {
+			rprintf(FLOG,
+				"rsync error: (3) Child proccess has CRASHED.\n");
+		}
+	}
 #endif
 #ifndef HAVE_SIGACTION
 	signal(SIGCHLD, sigchld_handler);
Commit	Line	Data
ae5c7864 WD	1	Igor Yu. Zhbanov wrote:
	2	> I am using rsync compiled with Cygwin on windows.
	3	> I must call rsync from the *.bat script (I don't want to use a bash on Windows)
	4	> and I have noticed that in the case when program compiled by Cygwin crashes
	5	> via segmentation fault and default SIGSEGV handler is called, then it
	6	> terminates process with exit status 0 as I see it from my *.bat script.
	7	> (But if I invoke a program from bash (compiled with Cygwin too) I will see
	8	> error code 139 as expected.)
	9	>
	10	> It is a Cygwin's problem, not an rsync's, but to use it on windows and
	11	> to distinguish situations when rsync crashes and when it exits normally,
	12	> I have written signal handler which terminates process with code 50.
	13	> You may use conventional 139. Also signal handler writes corresponding
	14	> message to log file.
	15	>
	16	> By the way. When I terminate rsync in daemon mode by pressing Control-C,
	17	> it writes an error to log. May be this is not an error but info or notice?
	18
	19	I'm not sure I like this, but if you run into the cygwin problem, this might
	20	prove helpful.
	21
03019e41 WD	22	To use this patch, run these commands for a successful build:
	23
	24	patch -p1 <patches/catch_crash_signals.diff
	25	./configure (optional if already run)
	26	make
	27
ae5c7864 WD	28	--- old/errcode.h
	29	+++ new/errcode.h
	30	@@ -47,6 +47,8 @@
	31
	32	#define RERR_TIMEOUT 30 /* timeout in data send/receive */
	33
	34	+#define RERR_WECRASHED 50 /* We have crashed. */
	35	+
	36	/* Although it doesn't seem to be specified anywhere,
	37	* ssh and the shell seem to return these values:
	38	*
	39	--- old/log.c
	40	+++ new/log.c
f2376a08	41	@@ -79,6 +79,7 @@ struct {
ae5c7864 WD	42	{ RERR_TERMINATED , "sibling process terminated abnormally" },
	43	{ RERR_SIGNAL1 , "received SIGUSR1" },
	44	{ RERR_SIGNAL , "received SIGINT, SIGTERM, or SIGHUP" },
	45	+ { RERR_WECRASHED , "rsync caught a CRASH-causing signal" },
	46	{ RERR_WAITCHILD , "waitpid() failed" },
	47	{ RERR_MALLOC , "error allocating core memory buffers" },
	48	{ RERR_PARTIAL , "some files could not be transferred" },
	49	--- old/main.c
	50	+++ new/main.c
f2376a08	51	@@ -155,8 +155,11 @@ static void wait_process_with_flush(pid_
ae5c7864 WD	52	*exit_code_ptr = RERR_TERMINATED;
	53	else
	54	*exit_code_ptr = RERR_WAITCHILD;
	55	- } else
	56	+ } else {
	57	*exit_code_ptr = WEXITSTATUS(status);
	58	+ if (*exit_code_ptr == RERR_WECRASHED)
	59	+ *exit_code_ptr = RERR_CRASHED;
	60	+ }
	61	}
	62
	63	/* This function gets called from all 3 processes. We want the client side
f2376a08	64	@@ -1234,6 +1237,14 @@ RETSIGTYPE remember_children(UNUSED(int
ae5c7864 WD	65	break;
	66	}
	67	}
	68	+ if (WIFSIGNALED(status)) {
	69	+ rprintf(FLOG,
	70	+ "rsync error: (1) Child proccess has unexpectedly died with signal %d\n",
	71	+ WTERMSIG(status));
	72	+ } else if (WIFEXITED(status) && WEXITSTATUS(status) == RERR_WECRASHED) {
	73	+ rprintf(FLOG,
	74	+ "rsync error: (1) Child proccess has CRASHED.\n");
	75	+ }
	76	}
	77	#endif
	78	#ifndef HAVE_SIGACTION
f2376a08	79	@@ -1292,6 +1303,12 @@ static RETSIGTYPE rsync_panic_handler(UN
ae5c7864 WD	80	}
	81	#endif
	82
	83	+static RETSIGTYPE rsync_crash_handler(UNUSED(int whatsig))
	84	+{
	85	+ log_exit(RERR_WECRASHED, __FILE__, __LINE__);
	86	+ logfile_close();
	87	+ _exit(RERR_WECRASHED);
	88	+}
	89
	90	int main(int argc,char *argv[])
	91	{
f2376a08	92	@@ -1314,6 +1331,11 @@ int main(int argc,char *argv[])
ae5c7864 WD	93	SIGACTMASK(SIGFPE, rsync_panic_handler);
	94	SIGACTMASK(SIGABRT, rsync_panic_handler);
	95	SIGACTMASK(SIGBUS, rsync_panic_handler);
	96	+#else
	97	+ SIGACTMASK(SIGSEGV, rsync_crash_handler);
	98	+ SIGACTMASK(SIGFPE, rsync_crash_handler);
	99	+ SIGACTMASK(SIGABRT, rsync_crash_handler);
	100	+ SIGACTMASK(SIGBUS, rsync_crash_handler);
	101	#endif
	102
	103	starttime = time(NULL);
	104	--- old/socket.c
	105	+++ new/socket.c
03019e41	106	@@ -454,7 +454,17 @@ int is_a_socket(int fd)
ae5c7864 WD	107	static RETSIGTYPE sigchld_handler(UNUSED(int val))
	108	{
	109	#ifdef WNOHANG
	110	- while (waitpid(-1, NULL, WNOHANG) > 0) {}
	111	+ int status;
	112	+ while (waitpid(-1, &status, WNOHANG) > 0) {
	113	+ if (WIFSIGNALED(status)) {
	114	+ rprintf(FLOG,
	115	+ "rsync error: (3) Child proccess has unexpectedly died with signal %d\n",
	116	+ WTERMSIG(status));
	117	+ } else if (WIFEXITED(status) && WEXITSTATUS(status) == RERR_WECRASHED) {
	118	+ rprintf(FLOG,
	119	+ "rsync error: (3) Child proccess has CRASHED.\n");
	120	+ }
	121	+ }
	122	#endif
	123	#ifndef HAVE_SIGACTION
	124	signal(SIGCHLD, sigchld_handler);