Commit 8c06da67 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'livepatching-for-6.10' of... 

Merge tag 'livepatching-for-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching

Pull livepatching update from Petr Mladek:

 - Use more informative names for the livepatch transition states

* tag 'livepatching-for-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching:
  livepatch: Rename KLP_* to KLP_TRANSITION_*
parents a19264d0 d927752f

include/linux/livepatch.h

+3 −3
Original line number Diff line number Diff line
@@ -18,9 +18,9 @@ 
#if IS_ENABLED(CONFIG_LIVEPATCH)



/* task patch states */

#define KLP_UNDEFINED	-1

#define KLP_UNPATCHED	 0

#define KLP_PATCHED	 1

#define KLP_TRANSITION_IDLE		-1

#define KLP_TRANSITION_UNPATCHED	 0

#define KLP_TRANSITION_PATCHED		 1



/**

 * struct klp_func - function structure for live patching

init/init_task.c

+1 −1
Original line number Diff line number Diff line
@@ -199,7 +199,7 @@ struct task_struct init_task __aligned(L1_CACHE_BYTES) = { 
	.trace_recursion = 0,

#endif

#ifdef CONFIG_LIVEPATCH

	.patch_state	= KLP_UNDEFINED,

	.patch_state	= KLP_TRANSITION_IDLE,

#endif

#ifdef CONFIG_SECURITY

	.security	= NULL,

kernel/livepatch/core.c

+2 −2
Original line number Diff line number Diff line
@@ -973,7 +973,7 @@ static int __klp_disable_patch(struct klp_patch *patch) 
	if (klp_transition_patch)

		return -EBUSY;



	klp_init_transition(patch, KLP_UNPATCHED);

	klp_init_transition(patch, KLP_TRANSITION_UNPATCHED);



	klp_for_each_object(patch, obj)

		if (obj->patched)
@@ -1008,7 +1008,7 @@ static int __klp_enable_patch(struct klp_patch *patch) 


	pr_notice("enabling patch '%s'\n", patch->mod->name);



	klp_init_transition(patch, KLP_PATCHED);

	klp_init_transition(patch, KLP_TRANSITION_PATCHED);



	/*

	 * Enforce the order of the func->transition writes in

kernel/livepatch/patch.c

+2 −2
Original line number Diff line number Diff line
@@ -95,9 +95,9 @@ static void notrace klp_ftrace_handler(unsigned long ip, 


		patch_state = current->patch_state;



		WARN_ON_ONCE(patch_state == KLP_UNDEFINED);

		WARN_ON_ONCE(patch_state == KLP_TRANSITION_IDLE);



		if (patch_state == KLP_UNPATCHED) {

		if (patch_state == KLP_TRANSITION_UNPATCHED) {

			/*

			 * Use the previously patched version of the function.

			 * If no previous patches exist, continue with the

kernel/livepatch/transition.c

+27 −27
Original line number Diff line number Diff line
@@ -23,7 +23,7 @@ static DEFINE_PER_CPU(unsigned long[MAX_STACK_ENTRIES], klp_stack_entries); 


struct klp_patch *klp_transition_patch;



static int klp_target_state = KLP_UNDEFINED;

static int klp_target_state = KLP_TRANSITION_IDLE;



static unsigned int klp_signals_cnt;
@@ -96,16 +96,16 @@ static void klp_complete_transition(void) 


	pr_debug("'%s': completing %s transition\n",

		 klp_transition_patch->mod->name,

		 klp_target_state == KLP_PATCHED ? "patching" : "unpatching");

		 klp_target_state == KLP_TRANSITION_PATCHED ? "patching" : "unpatching");



	if (klp_transition_patch->replace && klp_target_state == KLP_PATCHED) {

	if (klp_transition_patch->replace && klp_target_state == KLP_TRANSITION_PATCHED) {

		klp_unpatch_replaced_patches(klp_transition_patch);

		klp_discard_nops(klp_transition_patch);

	}



	if (klp_target_state == KLP_UNPATCHED) {

	if (klp_target_state == KLP_TRANSITION_UNPATCHED) {

		/*

		 * All tasks have transitioned to KLP_UNPATCHED so we can now

		 * All tasks have transitioned to KLP_TRANSITION_UNPATCHED so we can now

		 * remove the new functions from the func_stack.

		 */

		klp_unpatch_objects(klp_transition_patch);
@@ -123,36 +123,36 @@ static void klp_complete_transition(void) 
		klp_for_each_func(obj, func)

			func->transition = false;



	/* Prevent klp_ftrace_handler() from seeing KLP_UNDEFINED state */

	if (klp_target_state == KLP_PATCHED)

	/* Prevent klp_ftrace_handler() from seeing KLP_TRANSITION_IDLE state */

	if (klp_target_state == KLP_TRANSITION_PATCHED)

		klp_synchronize_transition();



	read_lock(&tasklist_lock);

	for_each_process_thread(g, task) {

		WARN_ON_ONCE(test_tsk_thread_flag(task, TIF_PATCH_PENDING));

		task->patch_state = KLP_UNDEFINED;

		task->patch_state = KLP_TRANSITION_IDLE;

	}

	read_unlock(&tasklist_lock);



	for_each_possible_cpu(cpu) {

		task = idle_task(cpu);

		WARN_ON_ONCE(test_tsk_thread_flag(task, TIF_PATCH_PENDING));

		task->patch_state = KLP_UNDEFINED;

		task->patch_state = KLP_TRANSITION_IDLE;

	}



	klp_for_each_object(klp_transition_patch, obj) {

		if (!klp_is_object_loaded(obj))

			continue;

		if (klp_target_state == KLP_PATCHED)

		if (klp_target_state == KLP_TRANSITION_PATCHED)

			klp_post_patch_callback(obj);

		else if (klp_target_state == KLP_UNPATCHED)

		else if (klp_target_state == KLP_TRANSITION_UNPATCHED)

			klp_post_unpatch_callback(obj);

	}



	pr_notice("'%s': %s complete\n", klp_transition_patch->mod->name,

		  klp_target_state == KLP_PATCHED ? "patching" : "unpatching");

		  klp_target_state == KLP_TRANSITION_PATCHED ? "patching" : "unpatching");



	klp_target_state = KLP_UNDEFINED;

	klp_target_state = KLP_TRANSITION_IDLE;

	klp_transition_patch = NULL;

}
@@ -164,13 +164,13 @@ static void klp_complete_transition(void) 
 */

void klp_cancel_transition(void)

{

	if (WARN_ON_ONCE(klp_target_state != KLP_PATCHED))

	if (WARN_ON_ONCE(klp_target_state != KLP_TRANSITION_PATCHED))

		return;



	pr_debug("'%s': canceling patching transition, going to unpatch\n",

		 klp_transition_patch->mod->name);



	klp_target_state = KLP_UNPATCHED;

	klp_target_state = KLP_TRANSITION_UNPATCHED;

	klp_complete_transition();

}
@@ -218,7 +218,7 @@ static int klp_check_stack_func(struct klp_func *func, unsigned long *entries, 
	struct klp_ops *ops;

	int i;



	if (klp_target_state == KLP_UNPATCHED) {

	if (klp_target_state == KLP_TRANSITION_UNPATCHED) {

		 /*

		  * Check for the to-be-unpatched function

		  * (the func itself).
@@ -455,7 +455,7 @@ void klp_try_complete_transition(void) 
	struct klp_patch *patch;

	bool complete = true;



	WARN_ON_ONCE(klp_target_state == KLP_UNDEFINED);

	WARN_ON_ONCE(klp_target_state == KLP_TRANSITION_IDLE);



	/*

	 * Try to switch the tasks to the target patch state by walking their
@@ -532,11 +532,11 @@ void klp_start_transition(void) 
	struct task_struct *g, *task;

	unsigned int cpu;



	WARN_ON_ONCE(klp_target_state == KLP_UNDEFINED);

	WARN_ON_ONCE(klp_target_state == KLP_TRANSITION_IDLE);



	pr_notice("'%s': starting %s transition\n",

		  klp_transition_patch->mod->name,

		  klp_target_state == KLP_PATCHED ? "patching" : "unpatching");

		  klp_target_state == KLP_TRANSITION_PATCHED ? "patching" : "unpatching");



	/*

	 * Mark all normal tasks as needing a patch state update.  They'll
@@ -578,7 +578,7 @@ void klp_init_transition(struct klp_patch *patch, int state) 
	struct klp_func *func;

	int initial_state = !state;



	WARN_ON_ONCE(klp_target_state != KLP_UNDEFINED);

	WARN_ON_ONCE(klp_target_state != KLP_TRANSITION_IDLE);



	klp_transition_patch = patch;
@@ -589,7 +589,7 @@ void klp_init_transition(struct klp_patch *patch, int state) 
	klp_target_state = state;



	pr_debug("'%s': initializing %s transition\n", patch->mod->name,

		 klp_target_state == KLP_PATCHED ? "patching" : "unpatching");

		 klp_target_state == KLP_TRANSITION_PATCHED ? "patching" : "unpatching");



	/*

	 * Initialize all tasks to the initial patch state to prepare them for
@@ -597,7 +597,7 @@ void klp_init_transition(struct klp_patch *patch, int state) 
	 */

	read_lock(&tasklist_lock);

	for_each_process_thread(g, task) {

		WARN_ON_ONCE(task->patch_state != KLP_UNDEFINED);

		WARN_ON_ONCE(task->patch_state != KLP_TRANSITION_IDLE);

		task->patch_state = initial_state;

	}

	read_unlock(&tasklist_lock);
@@ -607,19 +607,19 @@ void klp_init_transition(struct klp_patch *patch, int state) 
	 */

	for_each_possible_cpu(cpu) {

		task = idle_task(cpu);

		WARN_ON_ONCE(task->patch_state != KLP_UNDEFINED);

		WARN_ON_ONCE(task->patch_state != KLP_TRANSITION_IDLE);

		task->patch_state = initial_state;

	}



	/*

	 * Enforce the order of the task->patch_state initializations and the

	 * func->transition updates to ensure that klp_ftrace_handler() doesn't

	 * see a func in transition with a task->patch_state of KLP_UNDEFINED.

	 * see a func in transition with a task->patch_state of KLP_TRANSITION_IDLE.

	 *

	 * Also enforce the order of the klp_target_state write and future

	 * TIF_PATCH_PENDING writes to ensure klp_update_patch_state() and

	 * __klp_sched_try_switch() don't set a task->patch_state to

	 * KLP_UNDEFINED.

	 * KLP_TRANSITION_IDLE.

	 */

	smp_wmb();
@@ -652,7 +652,7 @@ void klp_reverse_transition(void) 


	pr_debug("'%s': reversing transition from %s\n",

		 klp_transition_patch->mod->name,

		 klp_target_state == KLP_PATCHED ? "patching to unpatching" :

		 klp_target_state == KLP_TRANSITION_PATCHED ? "patching to unpatching" :

						   "unpatching to patching");



	/*
@@ -741,7 +741,7 @@ void klp_force_transition(void) 
		klp_update_patch_state(idle_task(cpu));



	/* Set forced flag for patches being removed. */

	if (klp_target_state == KLP_UNPATCHED)

	if (klp_target_state == KLP_TRANSITION_UNPATCHED)

		klp_transition_patch->forced = true;

	else if (klp_transition_patch->replace) {

		klp_for_each_patch(patch) {