Commit 59766286 authored by Michael Vetter's avatar Michael Vetter Committed by Petr Mladek
Browse files

selftests: livepatch: save and restore kprobe state 



Save the state of /sys/kernel/debug/kprobes/enabled
during setup_config() and restore it during cleanup().

This is in preparation for a future commit that will add a test
that should confirm that we cannot livepatch a kprobed function
if that kprobe has a post handler.

Signed-off-by: default avatarMichael Vetter <mvetter@suse.com>
Reviewed-by: default avatarMiroslav Benes <mbenes@suse.cz>
Reviewed-by: default avatarJoe Lawrence <joe.lawrence@redhat.com>
Tested-by: default avatarMarcos Paulo de Souza <mpdesouza@suse.com>
Reviewed-by: default avatarMarcos Paulo de Souza <mpdesouza@suse.com>
Reviewed-by: default avatarPetr Mladek <pmladek@suse.com>
Tested-by: default avatarPetr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20241017200132.21946-3-mvetter@suse.com


[pmladek@suse.com: Added few more substitutions in test-syscall.sh]
Signed-off-by: default avatarPetr Mladek <pmladek@suse.com>
parent 637c7309

tools/testing/selftests/livepatch/functions.sh

+11 −4
Original line number Diff line number Diff line
@@ -6,7 +6,10 @@ 


MAX_RETRIES=600

RETRY_INTERVAL=".1"	# seconds

SYSFS_KLP_DIR="/sys/kernel/livepatch"

SYSFS_KERNEL_DIR="/sys/kernel"

SYSFS_KLP_DIR="$SYSFS_KERNEL_DIR/livepatch"

SYSFS_DEBUG_DIR="$SYSFS_KERNEL_DIR/debug"

SYSFS_KPROBES_DIR="$SYSFS_DEBUG_DIR/kprobes"



# Kselftest framework requirement - SKIP code is 4

ksft_skip=4
@@ -55,22 +58,26 @@ function die() { 
}



function push_config() {

	DYNAMIC_DEBUG=$(grep '^kernel/livepatch' /sys/kernel/debug/dynamic_debug/control | \

	DYNAMIC_DEBUG=$(grep '^kernel/livepatch' "$SYSFS_DEBUG_DIR/dynamic_debug/control" | \

			awk -F'[: ]' '{print "file " $1 " line " $2 " " $4}')

	FTRACE_ENABLED=$(sysctl --values kernel.ftrace_enabled)

	KPROBE_ENABLED=$(cat "$SYSFS_KPROBES_DIR/enabled")

}



function pop_config() {

	if [[ -n "$DYNAMIC_DEBUG" ]]; then

		echo -n "$DYNAMIC_DEBUG" > /sys/kernel/debug/dynamic_debug/control

		echo -n "$DYNAMIC_DEBUG" > "$SYSFS_DEBUG_DIR/dynamic_debug/control"

	fi

	if [[ -n "$FTRACE_ENABLED" ]]; then

		sysctl kernel.ftrace_enabled="$FTRACE_ENABLED" &> /dev/null

	fi

	if [[ -n "$KPROBE_ENABLED" ]]; then

		echo "$KPROBE_ENABLED" > "$SYSFS_KPROBES_DIR/enabled"

	fi

}



function set_dynamic_debug() {

        cat <<-EOF > /sys/kernel/debug/dynamic_debug/control

        cat <<-EOF > "$SYSFS_DEBUG_DIR/dynamic_debug/control"

		file kernel/livepatch/* +p

		func klp_try_switch_task -p

		EOF

tools/testing/selftests/livepatch/test-syscall.sh

+2 −2
Original line number Diff line number Diff line
@@ -27,9 +27,9 @@ pid_list=$(echo ${pids[@]} | tr ' ' ',') 
load_lp $MOD_SYSCALL klp_pids=$pid_list



# wait for all tasks to transition to patched state

loop_until 'grep -q '^0$' /sys/kernel/test_klp_syscall/npids'

loop_until 'grep -q '^0$' $SYSFS_KERNEL_DIR/$MOD_SYSCALL/npids'



pending_pids=$(cat /sys/kernel/test_klp_syscall/npids)

pending_pids=$(cat $SYSFS_KERNEL_DIR/$MOD_SYSCALL/npids)

log "$MOD_SYSCALL: Remaining not livepatched processes: $pending_pids"



for pid in ${pids[@]}; do