test/common: Always attempt to restore core_pattern

This setting may be crucial on some systems in keeping core dump files
in order, that's why we should always make sure it's main value is
restored upon exiting from autotest.sh.

Signed-off-by: Michal Berger <michalx.berger@intel.com>
Change-Id: I0c81a8c96c2d8f061e95c2614d9c30f4e3cdd5a6
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/3605
Community-CI: Mellanox Build Bot
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>

autotest.sh

@@ -24,6 +24,7 @@ if [ $EUID -ne 0 ]; then
 fi
 
 if [ $(uname -s) = Linux ]; then
+	old_core_pattern=$(< /proc/sys/kernel/core_pattern)
 	# set core_pattern to a known value to avoid ABRT, systemd-coredump, etc.
 	echo "core" > /proc/sys/kernel/core_pattern
 

test/common/autotest_common.sh

@@ -1208,6 +1208,9 @@ function autotest_cleanup() {
 		fi
 	fi
 	rm -rf "$asan_suppression_file"
+	if [[ -n $old_core_pattern ]]; then
+		echo "$old_core_pattern" > /proc/sys/kernel/core_pattern
+	fi
 }
 
 function freebsd_update_contigmem_mod() {