kpatch: clarify that "kpatch unload" isn't supported

Add a user-prompt to the kpatch unload subcommand and make a similiar

mention in the manual page.

Provide an undocumented force option so that QE and dev scripts can

still run unload kpatch modules from scripts.

RHEL-only.

Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>

diff -Nupr kpatch-0.6.1.old/kpatch/kpatch kpatch-0.6.1/kpatch/kpatch

--- kpatch-0.9.2.old/kpatch/kpatch	2019-08-28 10:35:01.191259434 -0400

+++ kpatch-0.9.2/kpatch/kpatch	2019-08-28 16:11:13.067926576 -0400

@@ -49,8 +49,8 @@ usage () {

 	echo >&2

 	usage_cmd "load --all" "load all installed patch modules into the running kernel"

 	usage_cmd "load <module>" "load patch module into the running kernel"

-	usage_cmd "unload --all" "unload all patch modules from the running kernel"

-	usage_cmd "unload <module>" "unload patch module from the running kernel"

+	usage_cmd "unload --all (UNSUPPORTED)" "unload all patch modules from the running kernel"

+	usage_cmd "unload <module> (UNSUPPORTED)" "unload patch module from the running kernel"

 	echo >&2

 	usage_cmd "info <module>" "show information about a patch module"

 	echo >&2

@@ -71,6 +71,16 @@ die() {

 	exit 1

 }

+confirm_prompt() {

+	local prompt="$1"

+	local answer

+	while true; do

+		read -rp "$prompt [Y/N] " answer

+		[[ $answer == 'Y' || $answer == 'y' ]] && return 0

+		[[ $answer == 'N' || $answer == 'n' ]] && return 1

+	done

+}

+

 __find_module () {

 	MODULE="$1"

 	[[ -f "$MODULE" ]] && return

@@ -406,6 +416,19 @@ unset MODULE

 init_sysfs_var

 [[ "$#" -lt 1 ]] && usage

+

+# RHEL-specific support options

+case "$1" in

+"force")

+	# For scripting purposes, support "kpatch force unload".

+	# Shift out the "force" to avoid the user-prompt check below.

+	shift

+	;;

+"unload")

+	confirm_prompt "WARNING: Red Hat doesn't support unloading of kpatches, continue anyway?" || exit 1

+	;;

+esac

+

 case "$1" in

 "load")

 	[[ "$#" -ne 2 ]] && usage

diff -Nupr kpatch-0.6.1.old/man/kpatch.1 kpatch-0.6.1/man/kpatch.1

--- kpatch-0.9.2.old/man/kpatch.1	2019-08-28 10:35:01.191259434 -0400

+++ kpatch-0.9.2/man/kpatch.1	2019-08-28 14:51:23.268198897 -0400

@@ -23,10 +23,10 @@ load --all

 load <module>

        load patch module into the running kernel

-unload --all

+unload --all (UNSUPPORTED)

        unload all patch modules from the running kernel

-unload <module>

+unload <module> (UNSUPPORTED)

        unload patch module from the running kernel

 info <module>