1 /*
2  * arch/arm/kernel/kprobes-test.h
3  *
4  * Copyright (C) 2011 Jon Medhurst <tixy@yxit.co.uk>.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  */
10 
11 #define VERBOSE 0 /* Set to '1' for more logging of test cases */
12 
13 #ifdef CONFIG_THUMB2_KERNEL
14 #define NORMAL_ISA "16"
15 #else
16 #define NORMAL_ISA "32"
17 #endif
18 
19 
20 /* Flags used in kprobe_test_flags */
21 #define TEST_FLAG_NO_ITBLOCK	(1<<0)
22 #define TEST_FLAG_FULL_ITBLOCK	(1<<1)
23 #define TEST_FLAG_NARROW_INSTR	(1<<2)
24 
25 extern int kprobe_test_flags;
26 extern int kprobe_test_cc_position;
27 
28 
29 #define TEST_MEMORY_SIZE 256
30 
31 
32 /*
33  * Test case structures.
34  *
35  * The arguments given to test cases can be one of three types.
36  *
37  *   ARG_TYPE_REG
38  *	Load a register with the given value.
39  *
40  *   ARG_TYPE_PTR
41  *	Load a register with a pointer into the stack buffer (SP + given value).
42  *
43  *   ARG_TYPE_MEM
44  *	Store the given value into the stack buffer at [SP+index].
45  *
46  */
47 
48 #define	ARG_TYPE_END	0
49 #define	ARG_TYPE_REG	1
50 #define	ARG_TYPE_PTR	2
51 #define	ARG_TYPE_MEM	3
52 
53 #define ARG_FLAG_UNSUPPORTED	0x01
54 #define ARG_FLAG_SUPPORTED	0x02
55 #define ARG_FLAG_THUMB		0x10	/* Must be 16 so TEST_ISA can be used */
56 #define ARG_FLAG_ARM		0x20	/* Must be 32 so TEST_ISA can be used */
57 
58 struct test_arg {
59 	u8	type;		/* ARG_TYPE_x */
60 	u8	_padding[7];
61 };
62 
63 struct test_arg_regptr {
64 	u8	type;		/* ARG_TYPE_REG or ARG_TYPE_PTR */
65 	u8	reg;
66 	u8	_padding[2];
67 	u32	val;
68 };
69 
70 struct test_arg_mem {
71 	u8	type;		/* ARG_TYPE_MEM */
72 	u8	index;
73 	u8	_padding[2];
74 	u32	val;
75 };
76 
77 struct test_arg_end {
78 	u8	type;		/* ARG_TYPE_END */
79 	u8	flags;		/* ARG_FLAG_x */
80 	u16	code_offset;
81 	u16	branch_offset;
82 	u16	end_offset;
83 };
84 
85 
86 /*
87  * Building blocks for test cases.
88  *
89  * Each test case is wrapped between TESTCASE_START and TESTCASE_END.
90  *
91  * To specify arguments for a test case the TEST_ARG_{REG,PTR,MEM} macros are
92  * used followed by a terminating TEST_ARG_END.
93  *
94  * After this, the instruction to be tested is defined with TEST_INSTRUCTION.
95  * Or for branches, TEST_BRANCH_B and TEST_BRANCH_F (branch forwards/backwards).
96  *
97  * Some specific test cases may make use of other custom constructs.
98  */
99 
100 #if VERBOSE
101 #define verbose(fmt, ...) pr_info(fmt, ##__VA_ARGS__)
102 #else
103 #define verbose(fmt, ...)
104 #endif
105 
106 #define TEST_GROUP(title)					\
107 	verbose("\n");						\
108 	verbose(title"\n");					\
109 	verbose("---------------------------------------------------------\n");
110 
111 #define TESTCASE_START(title)					\
112 	__asm__ __volatile__ (					\
113 	"bl	__kprobes_test_case_start		\n\t"	\
114 	/* don't use .asciz here as 'title' may be */		\
115 	/* multiple strings to be concatenated.  */		\
116 	".ascii "#title"				\n\t"	\
117 	".byte	0					\n\t"	\
118 	".align	2					\n\t"
119 
120 #define	TEST_ARG_REG(reg, val)					\
121 	".byte	"__stringify(ARG_TYPE_REG)"		\n\t"	\
122 	".byte	"#reg"					\n\t"	\
123 	".short	0					\n\t"	\
124 	".word	"#val"					\n\t"
125 
126 #define	TEST_ARG_PTR(reg, val)					\
127 	".byte	"__stringify(ARG_TYPE_PTR)"		\n\t"	\
128 	".byte	"#reg"					\n\t"	\
129 	".short	0					\n\t"	\
130 	".word	"#val"					\n\t"
131 
132 #define	TEST_ARG_MEM(index, val)				\
133 	".byte	"__stringify(ARG_TYPE_MEM)"		\n\t"	\
134 	".byte	"#index"				\n\t"	\
135 	".short	0					\n\t"	\
136 	".word	"#val"					\n\t"
137 
138 #define	TEST_ARG_END(flags)					\
139 	".byte	"__stringify(ARG_TYPE_END)"		\n\t"	\
140 	".byte	"TEST_ISA flags"			\n\t"	\
141 	".short	50f-0f					\n\t"	\
142 	".short	2f-0f					\n\t"	\
143 	".short	99f-0f					\n\t"	\
144 	".code "TEST_ISA"				\n\t"	\
145 	"0:						\n\t"
146 
147 #define TEST_INSTRUCTION(instruction)				\
148 	"50:	nop					\n\t"	\
149 	"1:	"instruction"				\n\t"	\
150 	"	nop					\n\t"
151 
152 #define TEST_BRANCH_F(instruction)				\
153 	TEST_INSTRUCTION(instruction)				\
154 	"	b	99f				\n\t"	\
155 	"2:	nop					\n\t"
156 
157 #define TEST_BRANCH_B(instruction)				\
158 	"	b	50f				\n\t"	\
159 	"	b	99f				\n\t"	\
160 	"2:	nop					\n\t"	\
161 	"	b	99f				\n\t"	\
162 	TEST_INSTRUCTION(instruction)
163 
164 #define TEST_BRANCH_FX(instruction, codex)			\
165 	TEST_INSTRUCTION(instruction)				\
166 	"	b	99f				\n\t"	\
167 	codex"						\n\t"	\
168 	"	b	99f				\n\t"	\
169 	"2:	nop					\n\t"
170 
171 #define TEST_BRANCH_BX(instruction, codex)			\
172 	"	b	50f				\n\t"	\
173 	"	b	99f				\n\t"	\
174 	"2:	nop					\n\t"	\
175 	"	b	99f				\n\t"	\
176 	codex"						\n\t"	\
177 	TEST_INSTRUCTION(instruction)
178 
179 #define TESTCASE_END						\
180 	"2:						\n\t"	\
181 	"99:						\n\t"	\
182 	"	bl __kprobes_test_case_end_"TEST_ISA"	\n\t"	\
183 	".code "NORMAL_ISA"				\n\t"	\
184 	: :							\
185 	: "r0", "r1", "r2", "r3", "ip", "lr", "memory", "cc"	\
186 	);
187 
188 
189 /*
190  * Macros to define test cases.
191  *
192  * Those of the form TEST_{R,P,M}* can be used to define test cases
193  * which take combinations of the three basic types of arguments. E.g.
194  *
195  *   TEST_R	One register argument
196  *   TEST_RR	Two register arguments
197  *   TEST_RPR	A register, a pointer, then a register argument
198  *
199  * For testing instructions which may branch, there are macros TEST_BF_*
200  * and TEST_BB_* for branching forwards and backwards.
201  *
202  * TEST_SUPPORTED and TEST_UNSUPPORTED don't cause the code to be executed,
203  * the just verify that a kprobe is or is not allowed on the given instruction.
204  */
205 
206 #define TEST(code)				\
207 	TESTCASE_START(code)			\
208 	TEST_ARG_END("")			\
209 	TEST_INSTRUCTION(code)			\
210 	TESTCASE_END
211 
212 #define TEST_UNSUPPORTED(code)					\
213 	TESTCASE_START(code)					\
214 	TEST_ARG_END("|"__stringify(ARG_FLAG_UNSUPPORTED))	\
215 	TEST_INSTRUCTION(code)					\
216 	TESTCASE_END
217 
218 #define TEST_SUPPORTED(code)					\
219 	TESTCASE_START(code)					\
220 	TEST_ARG_END("|"__stringify(ARG_FLAG_SUPPORTED))	\
221 	TEST_INSTRUCTION(code)					\
222 	TESTCASE_END
223 
224 #define TEST_R(code1, reg, val, code2)			\
225 	TESTCASE_START(code1 #reg code2)		\
226 	TEST_ARG_REG(reg, val)				\
227 	TEST_ARG_END("")				\
228 	TEST_INSTRUCTION(code1 #reg code2)		\
229 	TESTCASE_END
230 
231 #define TEST_RR(code1, reg1, val1, code2, reg2, val2, code3)	\
232 	TESTCASE_START(code1 #reg1 code2 #reg2 code3)		\
233 	TEST_ARG_REG(reg1, val1)				\
234 	TEST_ARG_REG(reg2, val2)				\
235 	TEST_ARG_END("")					\
236 	TEST_INSTRUCTION(code1 #reg1 code2 #reg2 code3)		\
237 	TESTCASE_END
238 
239 #define TEST_RRR(code1, reg1, val1, code2, reg2, val2, code3, reg3, val3, code4)\
240 	TESTCASE_START(code1 #reg1 code2 #reg2 code3 #reg3 code4)		\
241 	TEST_ARG_REG(reg1, val1)						\
242 	TEST_ARG_REG(reg2, val2)						\
243 	TEST_ARG_REG(reg3, val3)						\
244 	TEST_ARG_END("")							\
245 	TEST_INSTRUCTION(code1 #reg1 code2 #reg2 code3 #reg3 code4)		\
246 	TESTCASE_END
247 
248 #define TEST_RRRR(code1, reg1, val1, code2, reg2, val2, code3, reg3, val3, code4, reg4, val4)	\
249 	TESTCASE_START(code1 #reg1 code2 #reg2 code3 #reg3 code4 #reg4)		\
250 	TEST_ARG_REG(reg1, val1)						\
251 	TEST_ARG_REG(reg2, val2)						\
252 	TEST_ARG_REG(reg3, val3)						\
253 	TEST_ARG_REG(reg4, val4)						\
254 	TEST_ARG_END("")							\
255 	TEST_INSTRUCTION(code1 #reg1 code2 #reg2 code3 #reg3 code4 #reg4)	\
256 	TESTCASE_END
257 
258 #define TEST_P(code1, reg1, val1, code2)	\
259 	TESTCASE_START(code1 #reg1 code2)	\
260 	TEST_ARG_PTR(reg1, val1)		\
261 	TEST_ARG_END("")			\
262 	TEST_INSTRUCTION(code1 #reg1 code2)	\
263 	TESTCASE_END
264 
265 #define TEST_PR(code1, reg1, val1, code2, reg2, val2, code3)	\
266 	TESTCASE_START(code1 #reg1 code2 #reg2 code3)		\
267 	TEST_ARG_PTR(reg1, val1)				\
268 	TEST_ARG_REG(reg2, val2)				\
269 	TEST_ARG_END("")					\
270 	TEST_INSTRUCTION(code1 #reg1 code2 #reg2 code3)		\
271 	TESTCASE_END
272 
273 #define TEST_RP(code1, reg1, val1, code2, reg2, val2, code3)	\
274 	TESTCASE_START(code1 #reg1 code2 #reg2 code3)		\
275 	TEST_ARG_REG(reg1, val1)				\
276 	TEST_ARG_PTR(reg2, val2)				\
277 	TEST_ARG_END("")					\
278 	TEST_INSTRUCTION(code1 #reg1 code2 #reg2 code3)		\
279 	TESTCASE_END
280 
281 #define TEST_PRR(code1, reg1, val1, code2, reg2, val2, code3, reg3, val3, code4)\
282 	TESTCASE_START(code1 #reg1 code2 #reg2 code3 #reg3 code4)		\
283 	TEST_ARG_PTR(reg1, val1)						\
284 	TEST_ARG_REG(reg2, val2)						\
285 	TEST_ARG_REG(reg3, val3)						\
286 	TEST_ARG_END("")							\
287 	TEST_INSTRUCTION(code1 #reg1 code2 #reg2 code3 #reg3 code4)		\
288 	TESTCASE_END
289 
290 #define TEST_RPR(code1, reg1, val1, code2, reg2, val2, code3, reg3, val3, code4)\
291 	TESTCASE_START(code1 #reg1 code2 #reg2 code3 #reg3 code4)		\
292 	TEST_ARG_REG(reg1, val1)						\
293 	TEST_ARG_PTR(reg2, val2)						\
294 	TEST_ARG_REG(reg3, val3)						\
295 	TEST_ARG_END("")							\
296 	TEST_INSTRUCTION(code1 #reg1 code2 #reg2 code3 #reg3 code4)		\
297 	TESTCASE_END
298 
299 #define TEST_RRP(code1, reg1, val1, code2, reg2, val2, code3, reg3, val3, code4)\
300 	TESTCASE_START(code1 #reg1 code2 #reg2 code3 #reg3 code4)		\
301 	TEST_ARG_REG(reg1, val1)						\
302 	TEST_ARG_REG(reg2, val2)						\
303 	TEST_ARG_PTR(reg3, val3)						\
304 	TEST_ARG_END("")							\
305 	TEST_INSTRUCTION(code1 #reg1 code2 #reg2 code3 #reg3 code4)		\
306 	TESTCASE_END
307 
308 #define TEST_BF_P(code1, reg1, val1, code2)	\
309 	TESTCASE_START(code1 #reg1 code2)	\
310 	TEST_ARG_PTR(reg1, val1)		\
311 	TEST_ARG_END("")			\
312 	TEST_BRANCH_F(code1 #reg1 code2)	\
313 	TESTCASE_END
314 
315 #define TEST_BF(code)				\
316 	TESTCASE_START(code)			\
317 	TEST_ARG_END("")			\
318 	TEST_BRANCH_F(code)			\
319 	TESTCASE_END
320 
321 #define TEST_BB(code)				\
322 	TESTCASE_START(code)			\
323 	TEST_ARG_END("")			\
324 	TEST_BRANCH_B(code)			\
325 	TESTCASE_END
326 
327 #define TEST_BF_R(code1, reg, val, code2)	\
328 	TESTCASE_START(code1 #reg code2)	\
329 	TEST_ARG_REG(reg, val)			\
330 	TEST_ARG_END("")			\
331 	TEST_BRANCH_F(code1 #reg code2)		\
332 	TESTCASE_END
333 
334 #define TEST_BB_R(code1, reg, val, code2)	\
335 	TESTCASE_START(code1 #reg code2)	\
336 	TEST_ARG_REG(reg, val)			\
337 	TEST_ARG_END("")			\
338 	TEST_BRANCH_B(code1 #reg code2)		\
339 	TESTCASE_END
340 
341 #define TEST_BF_RR(code1, reg1, val1, code2, reg2, val2, code3)	\
342 	TESTCASE_START(code1 #reg1 code2 #reg2 code3)		\
343 	TEST_ARG_REG(reg1, val1)				\
344 	TEST_ARG_REG(reg2, val2)				\
345 	TEST_ARG_END("")					\
346 	TEST_BRANCH_F(code1 #reg1 code2 #reg2 code3)		\
347 	TESTCASE_END
348 
349 #define TEST_BF_X(code, codex)			\
350 	TESTCASE_START(code)			\
351 	TEST_ARG_END("")			\
352 	TEST_BRANCH_FX(code, codex)		\
353 	TESTCASE_END
354 
355 #define TEST_BB_X(code, codex)			\
356 	TESTCASE_START(code)			\
357 	TEST_ARG_END("")			\
358 	TEST_BRANCH_BX(code, codex)		\
359 	TESTCASE_END
360 
361 #define TEST_BF_RX(code1, reg, val, code2, codex)	\
362 	TESTCASE_START(code1 #reg code2)		\
363 	TEST_ARG_REG(reg, val)				\
364 	TEST_ARG_END("")				\
365 	TEST_BRANCH_FX(code1 #reg code2, codex)		\
366 	TESTCASE_END
367 
368 #define TEST_X(code, codex)			\
369 	TESTCASE_START(code)			\
370 	TEST_ARG_END("")			\
371 	TEST_INSTRUCTION(code)			\
372 	"	b	99f		\n\t"	\
373 	"	"codex"			\n\t"	\
374 	TESTCASE_END
375 
376 #define TEST_RX(code1, reg, val, code2, codex)		\
377 	TESTCASE_START(code1 #reg code2)		\
378 	TEST_ARG_REG(reg, val)				\
379 	TEST_ARG_END("")				\
380 	TEST_INSTRUCTION(code1 __stringify(reg) code2)	\
381 	"	b	99f		\n\t"		\
382 	"	"codex"			\n\t"		\
383 	TESTCASE_END
384 
385 #define TEST_RRX(code1, reg1, val1, code2, reg2, val2, code3, codex)		\
386 	TESTCASE_START(code1 #reg1 code2 #reg2 code3)				\
387 	TEST_ARG_REG(reg1, val1)						\
388 	TEST_ARG_REG(reg2, val2)						\
389 	TEST_ARG_END("")							\
390 	TEST_INSTRUCTION(code1 __stringify(reg1) code2 __stringify(reg2) code3)	\
391 	"	b	99f		\n\t"					\
392 	"	"codex"			\n\t"					\
393 	TESTCASE_END
394 
395 
396 /*
397  * Macros for defining space directives spread over multiple lines.
398  * These are required so the compiler guesses better the length of inline asm
399  * code and will spill the literal pool early enough to avoid generating PC
400  * relative loads with out of range offsets.
401  */
402 #define TWICE(x)	x x
403 #define SPACE_0x8	TWICE(".space 4\n\t")
404 #define SPACE_0x10	TWICE(SPACE_0x8)
405 #define SPACE_0x20	TWICE(SPACE_0x10)
406 #define SPACE_0x40	TWICE(SPACE_0x20)
407 #define SPACE_0x80	TWICE(SPACE_0x40)
408 #define SPACE_0x100	TWICE(SPACE_0x80)
409 #define SPACE_0x200	TWICE(SPACE_0x100)
410 #define SPACE_0x400	TWICE(SPACE_0x200)
411 #define SPACE_0x800	TWICE(SPACE_0x400)
412 #define SPACE_0x1000	TWICE(SPACE_0x800)
413 
414 
415 /* Various values used in test cases... */
416 #define N(val)	(val ^ 0xffffffff)
417 #define VAL1	0x12345678
418 #define VAL2	N(VAL1)
419 #define VAL3	0xa5f801
420 #define VAL4	N(VAL3)
421 #define VALM	0x456789ab
422 #define VALR	0xdeaddead
423 #define HH1	0x0123fecb
424 #define HH2	0xa9874567
425 
426 
427 #ifdef CONFIG_THUMB2_KERNEL
428 void kprobe_thumb16_test_cases(void);
429 void kprobe_thumb32_test_cases(void);
430 #else
431 void kprobe_arm_test_cases(void);
432 #endif
433