Commit 33608823 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'livepatching-for-6.14' of... 

Merge tag 'livepatching-for-6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching

Pull livepatching updates from Petr Mladek:

 - Add a sysfs attribute showing the livepatch ordering

 - Some code clean up

* tag 'livepatching-for-6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching:
  selftests: livepatch: add test cases of stack_order sysfs interface
  livepatch: Add stack_order sysfs attribute
  selftests/livepatch: Replace hardcoded module name with variable in test-callbacks.sh
parents 4ca6c022 49dcb50d

Documentation/ABI/testing/sysfs-kernel-livepatch

+9 −0
Original line number Diff line number Diff line
@@ -55,6 +55,15 @@ Description: 
		An attribute which indicates whether the patch supports

		atomic-replace.



What:		/sys/kernel/livepatch/<patch>/stack_order

Date:		Jan 2025

KernelVersion:	6.14.0

Description:

		This attribute specifies the sequence in which live patch modules

		are applied to the system. If multiple live patches modify the same

		function, the implementation with the biggest 'stack_order' number

		is used, unless a transition is currently in progress.



What:		/sys/kernel/livepatch/<patch>/<object>

Date:		Nov 2014

KernelVersion:	3.19.0

kernel/livepatch/core.c

+24 −0
Original line number Diff line number Diff line
@@ -347,6 +347,7 @@ int klp_apply_section_relocs(struct module *pmod, Elf_Shdr *sechdrs, 
 * /sys/kernel/livepatch/<patch>/transition

 * /sys/kernel/livepatch/<patch>/force

 * /sys/kernel/livepatch/<patch>/replace

 * /sys/kernel/livepatch/<patch>/stack_order

 * /sys/kernel/livepatch/<patch>/<object>

 * /sys/kernel/livepatch/<patch>/<object>/patched

 * /sys/kernel/livepatch/<patch>/<object>/<function,sympos>
@@ -452,15 +453,38 @@ static ssize_t replace_show(struct kobject *kobj, 
	return sysfs_emit(buf, "%d\n", patch->replace);

}



static ssize_t stack_order_show(struct kobject *kobj,

				struct kobj_attribute *attr, char *buf)

{

	struct klp_patch *patch, *this_patch;

	int stack_order = 0;



	this_patch = container_of(kobj, struct klp_patch, kobj);



	mutex_lock(&klp_mutex);



	klp_for_each_patch(patch) {

		stack_order++;

		if (patch == this_patch)

			break;

	}



	mutex_unlock(&klp_mutex);



	return sysfs_emit(buf, "%d\n", stack_order);

}



static struct kobj_attribute enabled_kobj_attr = __ATTR_RW(enabled);

static struct kobj_attribute transition_kobj_attr = __ATTR_RO(transition);

static struct kobj_attribute force_kobj_attr = __ATTR_WO(force);

static struct kobj_attribute replace_kobj_attr = __ATTR_RO(replace);

static struct kobj_attribute stack_order_kobj_attr = __ATTR_RO(stack_order);

static struct attribute *klp_patch_attrs[] = {

	&enabled_kobj_attr.attr,

	&transition_kobj_attr.attr,

	&force_kobj_attr.attr,

	&replace_kobj_attr.attr,

	&stack_order_kobj_attr.attr,

	NULL

};

ATTRIBUTE_GROUPS(klp_patch);

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

+1 −1
Original line number Diff line number Diff line
@@ -259,7 +259,7 @@ $MOD_TARGET: ${MOD_TARGET}_init 
% insmod test_modules/$MOD_LIVEPATCH.ko pre_patch_ret=-19

livepatch: enabling patch '$MOD_LIVEPATCH'

livepatch: '$MOD_LIVEPATCH': initializing patching transition

test_klp_callbacks_demo: pre_patch_callback: vmlinux

$MOD_LIVEPATCH: pre_patch_callback: vmlinux

livepatch: pre-patch callback failed for object 'vmlinux'

livepatch: failed to enable patch '$MOD_LIVEPATCH'

livepatch: '$MOD_LIVEPATCH': canceling patching transition, going to unpatch

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

+71 −0
Original line number Diff line number Diff line
@@ -5,6 +5,8 @@ 
. $(dirname $0)/functions.sh



MOD_LIVEPATCH=test_klp_livepatch

MOD_LIVEPATCH2=test_klp_callbacks_demo

MOD_LIVEPATCH3=test_klp_syscall



setup_config
@@ -19,6 +21,8 @@ check_sysfs_rights "$MOD_LIVEPATCH" "enabled" "-rw-r--r--" 
check_sysfs_value  "$MOD_LIVEPATCH" "enabled" "1"

check_sysfs_rights "$MOD_LIVEPATCH" "force" "--w-------"

check_sysfs_rights "$MOD_LIVEPATCH" "replace" "-r--r--r--"

check_sysfs_rights "$MOD_LIVEPATCH" "stack_order" "-r--r--r--"

check_sysfs_value  "$MOD_LIVEPATCH" "stack_order" "1"

check_sysfs_rights "$MOD_LIVEPATCH" "transition" "-r--r--r--"

check_sysfs_value  "$MOD_LIVEPATCH" "transition" "0"

check_sysfs_rights "$MOD_LIVEPATCH" "vmlinux/patched" "-r--r--r--"
@@ -131,4 +135,71 @@ livepatch: '$MOD_LIVEPATCH': completing unpatching transition 
livepatch: '$MOD_LIVEPATCH': unpatching complete

% rmmod $MOD_LIVEPATCH"



start_test "sysfs test stack_order value"



load_lp $MOD_LIVEPATCH



check_sysfs_value  "$MOD_LIVEPATCH" "stack_order" "1"



load_lp $MOD_LIVEPATCH2



check_sysfs_value  "$MOD_LIVEPATCH2" "stack_order" "2"



load_lp $MOD_LIVEPATCH3



check_sysfs_value  "$MOD_LIVEPATCH3" "stack_order" "3"



disable_lp $MOD_LIVEPATCH2

unload_lp $MOD_LIVEPATCH2



check_sysfs_value  "$MOD_LIVEPATCH" "stack_order" "1"

check_sysfs_value  "$MOD_LIVEPATCH3" "stack_order" "2"



disable_lp $MOD_LIVEPATCH3

unload_lp $MOD_LIVEPATCH3



disable_lp $MOD_LIVEPATCH

unload_lp $MOD_LIVEPATCH



check_result "% insmod test_modules/$MOD_LIVEPATCH.ko

livepatch: enabling patch '$MOD_LIVEPATCH'

livepatch: '$MOD_LIVEPATCH': initializing patching transition

livepatch: '$MOD_LIVEPATCH': starting patching transition

livepatch: '$MOD_LIVEPATCH': completing patching transition

livepatch: '$MOD_LIVEPATCH': patching complete

% insmod test_modules/$MOD_LIVEPATCH2.ko

livepatch: enabling patch '$MOD_LIVEPATCH2'

livepatch: '$MOD_LIVEPATCH2': initializing patching transition

$MOD_LIVEPATCH2: pre_patch_callback: vmlinux

livepatch: '$MOD_LIVEPATCH2': starting patching transition

livepatch: '$MOD_LIVEPATCH2': completing patching transition

$MOD_LIVEPATCH2: post_patch_callback: vmlinux

livepatch: '$MOD_LIVEPATCH2': patching complete

% insmod test_modules/$MOD_LIVEPATCH3.ko

livepatch: enabling patch '$MOD_LIVEPATCH3'

livepatch: '$MOD_LIVEPATCH3': initializing patching transition

livepatch: '$MOD_LIVEPATCH3': starting patching transition

livepatch: '$MOD_LIVEPATCH3': completing patching transition

livepatch: '$MOD_LIVEPATCH3': patching complete

% echo 0 > $SYSFS_KLP_DIR/$MOD_LIVEPATCH2/enabled

livepatch: '$MOD_LIVEPATCH2': initializing unpatching transition

$MOD_LIVEPATCH2: pre_unpatch_callback: vmlinux

livepatch: '$MOD_LIVEPATCH2': starting unpatching transition

livepatch: '$MOD_LIVEPATCH2': completing unpatching transition

$MOD_LIVEPATCH2: post_unpatch_callback: vmlinux

livepatch: '$MOD_LIVEPATCH2': unpatching complete

% rmmod $MOD_LIVEPATCH2

% echo 0 > $SYSFS_KLP_DIR/$MOD_LIVEPATCH3/enabled

livepatch: '$MOD_LIVEPATCH3': initializing unpatching transition

livepatch: '$MOD_LIVEPATCH3': starting unpatching transition

livepatch: '$MOD_LIVEPATCH3': completing unpatching transition

livepatch: '$MOD_LIVEPATCH3': unpatching complete

% rmmod $MOD_LIVEPATCH3

% echo 0 > $SYSFS_KLP_DIR/$MOD_LIVEPATCH/enabled

livepatch: '$MOD_LIVEPATCH': initializing unpatching transition

livepatch: '$MOD_LIVEPATCH': starting unpatching transition

livepatch: '$MOD_LIVEPATCH': completing unpatching transition

livepatch: '$MOD_LIVEPATCH': unpatching complete

% rmmod $MOD_LIVEPATCH"



exit 0