zloop: check if core file is generated by zdb

Run `gdb` core file inspection with correct program.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Gvozden Neskovic <neskovic@gmail.com>
Closes #5215

scripts/zloop.sh

@@ -70,7 +70,8 @@ coreglob="$(egrep -o '^([^|%[:space:]]*)' /proc/sys/kernel/core_pattern)*"
 if [[ $coreglob = "*" ]]; then
         echo "Setting core file pattern..."
         echo "core" > /proc/sys/kernel/core_pattern
-        coreglob="$(egrep -o '^([^|%[:space:]]*)' /proc/sys/kernel/core_pattern)*"
+        coreglob="$(egrep -o '^([^|%[:space:]]*)' \
+            /proc/sys/kernel/core_pattern)*"
 fi
 
 function core_file
@@ -78,6 +79,17 @@ function core_file
         printf "%s" "$(ls -tr1 $coreglob 2> /dev/null | head -1)"
 }
 
+function core_prog
+{
+	prog=$ZTEST
+	core_id=$($GDB --batch -c $1 | grep "Core was generated by" | \
+	    tr  \' ' ')
+	if [[ "$core_id" =~ "zdb "  ]]; then
+		prog=$ZDB
+	fi
+	printf "%s" "$prog"
+}
+
 function store_core
 {
 	core="$(core_file)"
@@ -99,6 +111,7 @@ function store_core
 
 		# check for core
 		if [[ -f "$core" ]]; then
+			coreprog=$(core_prog $core)
 			corestatus=$($GDB --batch --quiet \
 			    -ex "set print thread-events off" \
 			    -ex "printf \"*\n* Backtrace \n*\n\"" \
@@ -111,7 +124,7 @@ function store_core
 			    -ex "thread apply all bt" \
 			    -ex "printf \"*\n* Backtraces (full) \n*\n\"" \
 			    -ex "thread apply all bt full" \
-			    -ex "quit" $ZTEST "$core" | grep -v "New LWP")
+			    -ex "quit" $coreprog "$core" | grep -v "New LWP")
 
 			# Dump core + logs to stored directory
 			echo "$corestatus" >>$dest/status