trap sigsegv and add backtrace

src/backend/distributed/shared_library_init.c

@@ -27,6 +27,7 @@
 #include "commands/explain.h"
 #include "executor/executor.h"
 #include "distributed/backend_data.h"
+#include "distributed/backtrace.h"
 #include "distributed/citus_nodefuncs.h"
 #include "distributed/citus_safe_lib.h"
 #include "distributed/commands.h"
@@ -82,6 +83,8 @@
 #include "utils/guc_tables.h"
 #include "utils/varlena.h"
 
+#include <signal.h>
+
 /* marks shared object as one loadable by the postgres version compiled against */
 PG_MODULE_MAGIC;
 
@@ -90,6 +93,7 @@ static char *CitusVersion = CITUS_VERSION;
 
 
 void _PG_init(void);
+void handler(int sig);
 
 static void ResizeStackToMaximumDepth(void);
 static void multi_log_hook(ErrorData *edata);
@@ -189,7 +193,10 @@ static const struct config_enum_entry multi_shard_modify_connection_options[] =
 
 /* *INDENT-ON* */
 
-
+void handler(int sig) {
+	SignalBacktrace();
+	exit(1);
+}
 /* shared library initialization function */
 void
 _PG_init(void)
@@ -292,6 +299,7 @@ _PG_init(void)
 		SetConfigOption("allow_system_table_mods", "true", PGC_POSTMASTER,
 						PGC_S_OVERRIDE);
 	}
+	signal(SIGSEGV, handler);
 }
 
 
@@ -345,7 +353,6 @@ ResizeStackToMaximumDepth(void)
 #endif
 }
 
-
 /*
  * multi_log_hook intercepts postgres log commands. We use this to override
  * postgres error messages when they're not specific enough for the users.

src/backend/distributed/utils/backtrace.c

@@ -22,7 +22,7 @@ static int BacktraceFullCallback(void *data, uintptr_t pc,
 static void BacktraceErrorCallback(void *data, const char *msg, int errnum);
 static void InitBackTrace(void);
 static bool ShouldLogBacktrace(int elevel);
-static char * GenerateBackTrace(void);
+static char * GenerateBackTrace(int);
 
 static struct backtrace_state *backTracestate;
 
@@ -50,17 +50,22 @@ Backtrace(int elevel)
 	{
 		return;
 	}
-	errdetail("%s", GenerateBackTrace());
+	errdetail("%s", GenerateBackTrace(BACKTRACE_SKIP));
 }
 
 void AssertBacktrace(void) {
-	const char * backtrace = GenerateBackTrace();
+	const char * backtrace = GenerateBackTrace(BACKTRACE_SKIP);
     ereport(ERROR, (errmsg("%s", backtrace)));
 }
 
+void SignalBacktrace(void) {
+	const char * backtrace = GenerateBackTrace(BACKTRACE_SKIP + 1);
+    ereport(WARNING, (errmsg("%s", backtrace)));
+}
+
 
 static char *
-GenerateBackTrace(void)
+GenerateBackTrace(int skipAmount)
 {
 	if (backTracestate == NULL)
 	{
@@ -69,7 +74,7 @@ GenerateBackTrace(void)
 	StringInfo msgWithBacktrace = makeStringInfo();
 
 	appendStringInfoString(msgWithBacktrace, BACKTRACE_HEADER);
-	backtrace_full(backTracestate, BACKTRACE_SKIP, BacktraceFullCallback,
+	backtrace_full(backTracestate, skipAmount, BacktraceFullCallback,
 				   BacktraceErrorCallback, msgWithBacktrace);
 
 	return msgWithBacktrace->data;

src/include/distributed/backtrace.h

@@ -13,5 +13,6 @@
 
 void Backtrace(int elevel);
 void AssertBacktrace(void);
+void SignalBacktrace(void);
 
 #endif

src/include/distributed/log_utils.h

@@ -70,7 +70,6 @@ extern char * HashLogMessage(const char *text);
 #define Trap(condition, errorType) \
 	do { \
 		if (condition) { \
-			AssertBacktrace(); \
 			ExceptionalCondition(CppAsString(condition), (errorType), \
 								 __FILE__, __LINE__); \
 		} \