rtl88x2CE_WiFi_linux driver

hc

2024-05-10 cde9070d9970eef1f7ec2360586c802a16230ad8

 kernel/kernel/livepatch/patch.c
..
..
@@ -1,22 +1,10 @@
1
+// SPDX-License-Identifier: GPL-2.0-or-later
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2
 /*
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  * patch.c - livepatch patching functions
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4
  *
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5
  * Copyright (C) 2014 Seth Jennings <sjenning@redhat.com>
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  * Copyright (C) 2014 SUSE
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  * Copyright (C) 2015 Josh Poimboeuf <jpoimboe@redhat.com>
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- *
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- * This program is free software; you can redistribute it and/or
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- * modify it under the terms of the GNU General Public License
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- * as published by the Free Software Foundation; either version 2
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- * of the License, or (at your option) any later version.
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- *
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- * This program is distributed in the hope that it will be useful,
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- * but WITHOUT ANY WARRANTY; without even the implied warranty of
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- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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- * GNU General Public License for more details.
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- *
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- * You should have received a copy of the GNU General Public License
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- * along with this program; if not, see <http://www.gnu.org/licenses/>.
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8
  */
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9
 
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10
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
..
..
@@ -34,7 +22,7 @@
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22
 
35
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 static LIST_HEAD(klp_ops);
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24
 
37
-struct klp_ops *klp_find_ops(unsigned long old_addr)
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+struct klp_ops *klp_find_ops(void *old_func)
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26
 {
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 	struct klp_ops *ops;
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 	struct klp_func *func;
..
..
@@ -42,7 +30,7 @@
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 	list_for_each_entry(ops, &klp_ops, node) {
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 		func = list_first_entry(&ops->func_stack, struct klp_func,
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32
 					stack_node);
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-		if (func->old_addr == old_addr)
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+		if (func->old_func == old_func)
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34
 			return ops;
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35
 	}
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36
 
..
..
@@ -61,7 +49,7 @@
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49
 	ops = container_of(fops, struct klp_ops, fops);
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50
 
63
51
 	/*
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-	 * A variant of synchronize_sched() is used to allow patching functions
52
+	 * A variant of synchronize_rcu() is used to allow patching functions
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53
 	 * where RCU is not watching, see klp_synchronize_transition().
66
54
 	 */
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55
 	preempt_disable_notrace();
..
..
@@ -72,7 +60,7 @@
72
60
 	/*
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61
 	 * func should never be NULL because preemption should be disabled here
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62
 	 * and unregister_ftrace_function() does the equivalent of a
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-	 * synchronize_sched() before the func_stack removal.
63
+	 * synchronize_rcu() before the func_stack removal.
76
64
 	 */
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65
 	if (WARN_ON_ONCE(!func))
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66
 		goto unlock;
..
..
@@ -118,7 +106,15 @@
118
106
 		}
119
107
 	}
120
108
 
109
+	/*
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+	 * NOPs are used to replace existing patches with original code.
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+	 * Do nothing! Setting pc would cause an infinite loop.
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+	 */
113
+	if (func->nop)
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+		goto unlock;
115
+
121
116
 	klp_arch_set_pc(regs, (unsigned long)func->new_func);
117
+
122
118
 unlock:
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119
 	preempt_enable_notrace();
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120
 }
..
..
@@ -142,17 +138,18 @@
142
138
 
143
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 	if (WARN_ON(!func->patched))
144
140
 		return;
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-	if (WARN_ON(!func->old_addr))
141
+	if (WARN_ON(!func->old_func))
146
142
 		return;
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143
 
148
-	ops = klp_find_ops(func->old_addr);
144
+	ops = klp_find_ops(func->old_func);
149
145
 	if (WARN_ON(!ops))
150
146
 		return;
151
147
 
152
148
 	if (list_is_singular(&ops->func_stack)) {
153
149
 		unsigned long ftrace_loc;
154
150
 
155
-		ftrace_loc = klp_get_ftrace_location(func->old_addr);
151
+		ftrace_loc =
152
+			klp_get_ftrace_location((unsigned long)func->old_func);
156
153
 		if (WARN_ON(!ftrace_loc))
157
154
 			return;
158
155
 
..
..
@@ -174,17 +171,18 @@
174
171
 	struct klp_ops *ops;
175
172
 	int ret;
176
173
 
177
-	if (WARN_ON(!func->old_addr))
174
+	if (WARN_ON(!func->old_func))
178
175
 		return -EINVAL;
179
176
 
180
177
 	if (WARN_ON(func->patched))
181
178
 		return -EINVAL;
182
179
 
183
-	ops = klp_find_ops(func->old_addr);
180
+	ops = klp_find_ops(func->old_func);
184
181
 	if (!ops) {
185
182
 		unsigned long ftrace_loc;
186
183
 
187
-		ftrace_loc = klp_get_ftrace_location(func->old_addr);
184
+		ftrace_loc =
185
+			klp_get_ftrace_location((unsigned long)func->old_func);
188
186
 		if (!ftrace_loc) {
189
187
 			pr_err("failed to find location for function '%s'\n",
190
188
 				func->old_name);
..
..
@@ -198,7 +196,8 @@
198
196
 		ops->fops.func = klp_ftrace_handler;
199
197
 		ops->fops.flags = FTRACE_OPS_FL_SAVE_REGS |
200
198
 				  FTRACE_OPS_FL_DYNAMIC |
201
-				  FTRACE_OPS_FL_IPMODIFY;
199
+				  FTRACE_OPS_FL_IPMODIFY |
200
+				  FTRACE_OPS_FL_PERMANENT;
202
201
 
203
202
 		list_add(&ops->node, &klp_ops);
204
203
 
..
..
@@ -236,15 +235,26 @@
236
235
 	return ret;
237
236
 }
238
237
 
239
-void klp_unpatch_object(struct klp_object *obj)
238
+static void __klp_unpatch_object(struct klp_object *obj, bool nops_only)
240
239
 {
241
240
 	struct klp_func *func;
242
241
 
243
-	klp_for_each_func(obj, func)
242
+	klp_for_each_func(obj, func) {
243
+		if (nops_only && !func->nop)
244
+			continue;
245
+
244
246
 		if (func->patched)
245
247
 			klp_unpatch_func(func);
248
+	}
246
249
 
247
-	obj->patched = false;
250
+	if (obj->dynamic || !nops_only)
251
+		obj->patched = false;
252
+}
253
+
254
+
255
+void klp_unpatch_object(struct klp_object *obj)
256
+{
257
+	__klp_unpatch_object(obj, false);
248
258
 }
249
259
 
250
260
 int klp_patch_object(struct klp_object *obj)
..
..
@@ -267,11 +277,21 @@
267
277
 	return 0;
268
278
 }
269
279
 
270
-void klp_unpatch_objects(struct klp_patch *patch)
280
+static void __klp_unpatch_objects(struct klp_patch *patch, bool nops_only)
271
281
 {
272
282
 	struct klp_object *obj;
273
283
 
274
284
 	klp_for_each_object(patch, obj)
275
285
 		if (obj->patched)
276
-			klp_unpatch_object(obj);
286
+			__klp_unpatch_object(obj, nops_only);
287
+}
288
+
289
+void klp_unpatch_objects(struct klp_patch *patch)
290
+{
291
+	__klp_unpatch_objects(patch, false);
292
+}
293
+
294
+void klp_unpatch_objects_dynamic(struct klp_patch *patch)
295
+{
296
+	__klp_unpatch_objects(patch, true);
277
297
 }