tests: revert back to original coredump patterns on Linux, too

Otherwise, they leak past the tests and contaminate the running system,
breaking coredumps entirely

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Co-authored-by: Yannick Le Pennec <yannick.lepennec@live.fr>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #13259

scripts/zloop.sh

@@ -79,7 +79,7 @@ FreeBSD)
 	;;
 Linux)
 	# core file helpers
-	origcorepattern="$(cat /proc/sys/kernel/core_pattern)"
+	read -r origcorepattern </proc/sys/kernel/core_pattern
 	coreglob="$(grep -E -o '^([^|%[:space:]]*)' /proc/sys/kernel/core_pattern)*"
 
 	if [[ $coreglob = "*" ]]; then

tests/zfs-tests/include/libtest.shlib

@@ -3999,3 +3999,47 @@ function replay_directory_diff # dir_a dir_b
 {
 	LIBTEST_DIFF_ZIL_REPLAY=1 directory_diff "$@"
 }
+
+#
+# Put coredumps into $1/core.{basename}
+#
+# Output must be saved and passed to pop_coredump_pattern on cleanup
+#
+function push_coredump_pattern # dir
+{
+	ulimit -c unlimited
+	case $(uname) in
+	Linux)
+		cat /proc/sys/kernel/core_pattern /proc/sys/kernel/core_uses_pid
+		echo "$1/core.%e" >/proc/sys/kernel/core_pattern &&
+		    echo 0 >/proc/sys/kernel/core_uses_pid
+		;;
+	FreeBSD)
+		sysctl -n kern.corefile
+		sysctl kern.corefile="$1/core.%N" >/dev/null
+		;;
+	*)
+		# Nothing to output – set only for this shell
+		coreadm -p "$1/core.%f"
+		;;
+	esac
+}
+
+#
+# Put coredumps back into the default location
+#
+function pop_coredump_pattern
+{
+	[ -s "$1" ] || return 0
+	case $(uname) in
+	Linux)
+		typeset pat pid
+		{ read -r pat; read -r pid; } < "$1"
+		echo "$pat" >/proc/sys/kernel/core_pattern &&
+		    echo "$pid" >/proc/sys/kernel/core_uses_pid
+		;;
+	FreeBSD)
+		sysctl kern.corefile="$(<"$1")" >/dev/null
+		;;
+	esac
+}

tests/zfs-tests/tests/functional/cli_root/zfs/zfs_002_pos.ksh

@@ -48,33 +48,23 @@ function cleanup
 {
 	unset ZFS_ABORT
 
-	if is_freebsd && [[ -n $savedcorefile ]]; then
-		sysctl kern.corefile=$savedcorefile
-	fi
+	log_must pop_coredump_pattern "$coresavepath"
 
-	if [[ -d $corepath ]]; then
-		rm -rf $corepath
-	fi
 	for ds in $fs1 $fs $ctr; do
 		datasetexists $ds && destroy_dataset $ds -rRf
 	done
 }
 
-log_assert "With ZFS_ABORT set, all zfs commands can abort and generate a " \
-    "core file."
+log_assert "With ZFS_ABORT set, all zfs commands can abort and generate a core file."
 log_onexit cleanup
 
-# Preparation work for testing
-savedcorefile=""
-corepath=$TESTDIR/core
-corefile=$corepath/core.zfs
-if [[ -d $corepath ]]; then
-	rm -rf $corepath
-fi
-log_must mkdir $corepath
-
 ctr=$TESTPOOL/$TESTCTR
-log_must zfs create $ctr
+log_must zfs create -p $ctr
+
+# Preparation work for testing
+corepath=/$ctr
+corefile=$corepath/core.zfs
+coresavepath=$corepath/save
 
 fs=$ctr/$TESTFS
 fs1=$ctr/$TESTFS1
@@ -93,24 +83,12 @@ typeset badparams=("" "create" "destroy" "snapshot" "rollback" "clone" \
     "promote" "rename" "list -*" "set" "get -*" "inherit" "mount -A" \
     "unmount" "share" "unshare" "send" "receive")
 
-if is_linux; then
-	ulimit -c unlimited
-	echo "$corefile" >/proc/sys/kernel/core_pattern
-	echo 0 >/proc/sys/kernel/core_uses_pid
-elif is_freebsd; then
-	ulimit -c unlimited
-	savedcorefile=$(sysctl -n kern.corefile)
-	log_must sysctl kern.corefile=$corepath/core.%N
-else
-	log_must coreadm -p ${corepath}/core.%f
-fi
-
+log_must eval "push_coredump_pattern \"$corepath\" > \"$coresavepath\""
 log_must export ZFS_ABORT=yes
 
 for subcmd in "${cmds[@]}" "${badparams[@]}"; do
-	log_mustnot eval "zfs $subcmd >/dev/null 2>&1"
-	log_must rm $corefile
+	log_mustnot eval "zfs $subcmd"
+	log_must rm "$corefile"
 done
 
-log_pass "With ZFS_ABORT set, zfs command can abort and generate core file " \
-    "as expected."
+log_pass "With ZFS_ABORT set, zfs command can abort and generate core file as expected."

tests/zfs-tests/tests/functional/cli_root/zpool/zpool_002_pos.ksh

@@ -47,33 +47,27 @@ function cleanup
 {
 	unset ZFS_ABORT
 
-	if is_freebsd && [ -n "$old_corefile" ]; then
-		sysctl kern.corefile=$old_corefile
-	fi
+	log_must pop_coredump_pattern "$coresavepath"
+	log_must rm -rf $corepath $vdev1 $vdev2 $vdev3
 
 	# Clean up the pool created if we failed to abort.
 	poolexists $pool && destroy_pool $pool
-
-	rm -rf $corepath $vdev1 $vdev2 $vdev3
 }
 
 log_assert "With ZFS_ABORT set, all zpool commands can abort and generate a core file."
 log_onexit cleanup
 
 corepath=$TESTDIR/core
-corefile=$corepath/zpool.core
-if [[ -d $corepath ]]; then
-	log_must rm -rf $corepath
-fi
+corefile=$corepath/core.zpool
+coresavepath=$corepath/save
+log_must rm -rf $corepath
 log_must mkdir $corepath
 
 pool=pool.$$
 vdev1=$TESTDIR/file1
 vdev2=$TESTDIR/file2
 vdev3=$TESTDIR/file3
-for vdev in $vdev1 $vdev2 $vdev3; do
-	log_must mkfile $MINVDEVSIZE $vdev
-done
+log_must mkfile $MINVDEVSIZE $vdev1 $vdev2 $vdev3
 
 set -A cmds "create $pool mirror $vdev1 $vdev2" "list $pool" "iostat $pool" \
 	"status $pool" "upgrade $pool" "get delegation $pool" "set delegation=off $pool" \
@@ -86,25 +80,12 @@ set -A badparams "" "create" "destroy" "add" "remove" "list *" "iostat" "status"
 		"online" "offline" "clear" "attach" "detach" "replace" "scrub" \
 		"import" "export" "upgrade" "history -?" "get" "set"
 
-if is_linux; then
-	echo $corefile >/proc/sys/kernel/core_pattern
-	echo 0 >/proc/sys/kernel/core_uses_pid
-elif is_freebsd; then
-	old_corefile=$(sysctl -n kern.corefile)
-	log_must sysctl kern.corefile=$corefile
-fi
-ulimit -c unlimited
-
-export ZFS_ABORT=yes
+log_must eval "push_coredump_pattern \"$corepath\" > \"$coresavepath\""
+log_must export ZFS_ABORT=yes
 
 for subcmd in "${cmds[@]}" "${badparams[@]}"; do
-	zpool $subcmd >/dev/null 2>&1
-	if [[ ! -e $corefile ]]; then
-		log_fail "zpool $subcmd cannot generate core file with ZFS_ABORT set."
-	fi
-	rm -f $corefile
+	log_mustnot eval "zpool $subcmd"
+	log_must rm "$corefile"
 done
 
-unset ZFS_ABORT
-
 log_pass "With ZFS_ABORT set, zpool command can abort and generate core file as expected."

tests/zfs-tests/tests/functional/cli_root/zpool/zpool_003_pos.ksh

@@ -46,15 +46,12 @@ function cleanup
 {
 	unset ZFS_ABORT
 
-	if is_freebsd && [ -n "$old_corefile" ]; then
-		sysctl kern.corefile=$old_corefile
-	fi
-
-	rm -rf $corepath
+	log_must pop_coredump_pattern "$coresavepath"
+	log_must rm -rf $corepath
 
 	# Don't leave the pool frozen.
-	destroy_pool $TESTPOOL
-	default_mirror_setup $DISKS
+	log_must destroy_pool $TESTPOOL
+	log_must default_mirror_setup $DISKS
 }
 
 verify_runnable "both"
@@ -63,15 +60,14 @@ log_assert "Debugging features of zpool should succeed."
 log_onexit cleanup
 
 corepath=$TESTDIR/core
-corefile=$corepath/zpool.core
-if [[ -d $corepath ]]; then
-	log_must rm -rf $corepath
-fi
+corefile=$corepath/core.zpool
+coresavepath=$corepath/save
+log_must rm -rf $corepath
 log_must mkdir $corepath
 
 log_must eval "zpool -? >/dev/null 2>&1"
 
-if is_global_zone ; then
+if is_global_zone; then
 	log_must zpool freeze $TESTPOOL
 else
 	log_mustnot zpool freeze $TESTPOOL
@@ -80,21 +76,10 @@ fi
 
 log_mustnot zpool freeze fakepool
 
-if is_linux; then
-	echo $corefile >/proc/sys/kernel/core_pattern
-	echo 0 >/proc/sys/kernel/core_uses_pid
-elif is_freebsd; then
-	old_corefile=$(sysctl -n kern.corefile)
-	log_must sysctl kern.corefile=$corefile
-fi
-ulimit -c unlimited
+log_must eval "push_coredump_pattern \"$corepath\" > \"$coresavepath\""
+log_must export ZFS_ABORT=yes
 
-export ZFS_ABORT=yes
-
-zpool >/dev/null 2>&1
-
-unset ZFS_ABORT
-
-[[ -f $corefile ]] || log_fail "zpool did not dump core by request."
+log_mustnot eval "zpool >/dev/null 2>&1"
+log_must [ -f "$corefile" ]
 
 log_pass "Debugging features of zpool succeed."