Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) // SPDX-License-Identifier: GPL-2.0-or-later
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3)  * patch.c - livepatch patching functions
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5)  * Copyright (C) 2014 Seth Jennings <sjenning@redhat.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6)  * Copyright (C) 2014 SUSE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7)  * Copyright (C) 2015 Josh Poimboeuf <jpoimboe@redhat.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10) #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12) #include <linux/livepatch.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13) #include <linux/list.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14) #include <linux/ftrace.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15) #include <linux/rculist.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17) #include <linux/bug.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18) #include <linux/printk.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19) #include "core.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) #include "patch.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21) #include "transition.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23) static LIST_HEAD(klp_ops);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) struct klp_ops *klp_find_ops(void *old_func)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) 	struct klp_ops *ops;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) 	struct klp_func *func;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) 	list_for_each_entry(ops, &klp_ops, node) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) 		func = list_first_entry(&ops->func_stack, struct klp_func,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) 					stack_node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) 		if (func->old_func == old_func)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) 			return ops;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) 	return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) static void notrace klp_ftrace_handler(unsigned long ip,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) 				       unsigned long parent_ip,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) 				       struct ftrace_ops *fops,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) 				       struct pt_regs *regs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) 	struct klp_ops *ops;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) 	struct klp_func *func;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) 	int patch_state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) 	ops = container_of(fops, struct klp_ops, fops);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) 	 * A variant of synchronize_rcu() is used to allow patching functions
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) 	 * where RCU is not watching, see klp_synchronize_transition().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) 	preempt_disable_notrace();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 	func = list_first_or_null_rcu(&ops->func_stack, struct klp_func,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) 				      stack_node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) 	 * func should never be NULL because preemption should be disabled here
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) 	 * and unregister_ftrace_function() does the equivalent of a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) 	 * synchronize_rcu() before the func_stack removal.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) 	if (WARN_ON_ONCE(!func))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) 		goto unlock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) 	 * In the enable path, enforce the order of the ops->func_stack and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) 	 * func->transition reads.  The corresponding write barrier is in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) 	 * __klp_enable_patch().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) 	 *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) 	 * (Note that this barrier technically isn't needed in the disable
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) 	 * path.  In the rare case where klp_update_patch_state() runs before
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) 	 * this handler, its TIF_PATCH_PENDING read and this func->transition
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) 	 * read need to be ordered.  But klp_update_patch_state() already
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 	 * enforces that.)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 	smp_rmb();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) 	if (unlikely(func->transition)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) 		/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 		 * Enforce the order of the func->transition and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 		 * current->patch_state reads.  Otherwise we could read an
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) 		 * out-of-date task state and pick the wrong function.  The
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 		 * corresponding write barrier is in klp_init_transition().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 		 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 		smp_rmb();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) 		patch_state = current->patch_state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) 		WARN_ON_ONCE(patch_state == KLP_UNDEFINED);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) 		if (patch_state == KLP_UNPATCHED) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) 			/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) 			 * Use the previously patched version of the function.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) 			 * If no previous patches exist, continue with the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 			 * original function.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) 			 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) 			func = list_entry_rcu(func->stack_node.next,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) 					      struct klp_func, stack_node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) 			if (&func->stack_node == &ops->func_stack)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) 				goto unlock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) 	 * NOPs are used to replace existing patches with original code.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) 	 * Do nothing! Setting pc would cause an infinite loop.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) 	if (func->nop)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) 		goto unlock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) 	klp_arch_set_pc(regs, (unsigned long)func->new_func);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) unlock:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) 	preempt_enable_notrace();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123)  * Convert a function address into the appropriate ftrace location.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125)  * Usually this is just the address of the function, but on some architectures
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126)  * it's more complicated so allow them to provide a custom behaviour.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) #ifndef klp_get_ftrace_location
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) static unsigned long klp_get_ftrace_location(unsigned long faddr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) 	return faddr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) static void klp_unpatch_func(struct klp_func *func)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) 	struct klp_ops *ops;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) 	if (WARN_ON(!func->patched))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) 	if (WARN_ON(!func->old_func))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) 	ops = klp_find_ops(func->old_func);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) 	if (WARN_ON(!ops))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) 	if (list_is_singular(&ops->func_stack)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) 		unsigned long ftrace_loc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) 		ftrace_loc =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) 			klp_get_ftrace_location((unsigned long)func->old_func);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) 		if (WARN_ON(!ftrace_loc))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) 			return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 		WARN_ON(unregister_ftrace_function(&ops->fops));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) 		WARN_ON(ftrace_set_filter_ip(&ops->fops, ftrace_loc, 1, 0));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 		list_del_rcu(&func->stack_node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) 		list_del(&ops->node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) 		kfree(ops);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) 	} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) 		list_del_rcu(&func->stack_node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) 	func->patched = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) static int klp_patch_func(struct klp_func *func)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) 	struct klp_ops *ops;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) 	int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) 	if (WARN_ON(!func->old_func))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) 		return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) 	if (WARN_ON(func->patched))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) 		return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) 	ops = klp_find_ops(func->old_func);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) 	if (!ops) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) 		unsigned long ftrace_loc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 		ftrace_loc =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) 			klp_get_ftrace_location((unsigned long)func->old_func);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) 		if (!ftrace_loc) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) 			pr_err("failed to find location for function '%s'\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) 				func->old_name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) 			return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) 		ops = kzalloc(sizeof(*ops), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) 		if (!ops)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) 			return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) 		ops->fops.func = klp_ftrace_handler;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) 		ops->fops.flags = FTRACE_OPS_FL_SAVE_REGS |
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) 				  FTRACE_OPS_FL_DYNAMIC |
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) 				  FTRACE_OPS_FL_IPMODIFY |
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) 				  FTRACE_OPS_FL_PERMANENT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) 		list_add(&ops->node, &klp_ops);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) 		INIT_LIST_HEAD(&ops->func_stack);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) 		list_add_rcu(&func->stack_node, &ops->func_stack);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) 		ret = ftrace_set_filter_ip(&ops->fops, ftrace_loc, 0, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) 		if (ret) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) 			pr_err("failed to set ftrace filter for function '%s' (%d)\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) 			       func->old_name, ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) 			goto err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) 		ret = register_ftrace_function(&ops->fops);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) 		if (ret) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) 			pr_err("failed to register ftrace handler for function '%s' (%d)\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) 			       func->old_name, ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) 			ftrace_set_filter_ip(&ops->fops, ftrace_loc, 1, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) 			goto err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) 	} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) 		list_add_rcu(&func->stack_node, &ops->func_stack);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) 	func->patched = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) err:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) 	list_del_rcu(&func->stack_node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) 	list_del(&ops->node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) 	kfree(ops);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) 	return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) static void __klp_unpatch_object(struct klp_object *obj, bool nops_only)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) 	struct klp_func *func;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) 	klp_for_each_func(obj, func) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) 		if (nops_only && !func->nop)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) 			continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) 		if (func->patched)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) 			klp_unpatch_func(func);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) 	if (obj->dynamic || !nops_only)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) 		obj->patched = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) void klp_unpatch_object(struct klp_object *obj)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) 	__klp_unpatch_object(obj, false);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) int klp_patch_object(struct klp_object *obj)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) 	struct klp_func *func;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) 	int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) 	if (WARN_ON(obj->patched))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) 		return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) 	klp_for_each_func(obj, func) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) 		ret = klp_patch_func(func);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) 		if (ret) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) 			klp_unpatch_object(obj);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) 			return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) 	obj->patched = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) static void __klp_unpatch_objects(struct klp_patch *patch, bool nops_only)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) 	struct klp_object *obj;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) 	klp_for_each_object(patch, obj)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) 		if (obj->patched)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) 			__klp_unpatch_object(obj, nops_only);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) void klp_unpatch_objects(struct klp_patch *patch)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) 	__klp_unpatch_objects(patch, false);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) void klp_unpatch_objects_dynamic(struct klp_patch *patch)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) 	__klp_unpatch_objects(patch, true);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) }