[deliverable/linux.git] / tools / testing / selftests / rseq / rseq-x86.h

/*
 * rseq-x86.h
 *
 * (C) Copyright 2016 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#ifdef __x86_64__

#define smp_mb()	__asm__ __volatile__ ("mfence" : : : "memory")
#define smp_rmb()	barrier()
#define smp_wmb()	barrier()

#define smp_load_acquire(p)						\
__extension__ ({							\
	__typeof(*p) ____p1 = READ_ONCE(*p);				\
	barrier();							\
	____p1;								\
})

#define smp_acquire__after_ctrl_dep()	smp_rmb()

#define smp_store_release(p, v)						\
do {									\
	barrier();							\
	WRITE_ONCE(*p, v);						\
} while (0)

#define has_fast_acquire_release()	1
#define has_single_copy_load_64()	1

/*
 * The __rseq_table section can be used by debuggers to better handle
 * single-stepping through the restartable critical sections.
 */
#define RSEQ_FINISH_ASM(_target_final, _to_write_final, _start_value, \
		_failure, _spec_store, _spec_input, \
		_final_store, _final_input, _extra_clobber, \
		_setup, _teardown, _scratch) \
do { \
	_scratch \
	__asm__ __volatile__ goto ( \
		".pushsection __rseq_table, \"aw\"\n\t" \
		".balign 32\n\t" \
		"3:\n\t" \
		".quad 1f, 2f, 4f, 0x0\n\t" \
		".popsection\n\t" \
		"1:\n\t" \
		_setup \
		RSEQ_INJECT_ASM(1) \
		"leaq 3b(%%rip), %%rax\n\t" \
		"movq %%rax, %[rseq_cs]\n\t" \
		RSEQ_INJECT_ASM(2) \
		"cmpl %[start_event_counter], %[current_event_counter]\n\t" \
		"jnz 4f\n\t" \
		RSEQ_INJECT_ASM(3) \
		_spec_store \
		_final_store \
		"2:\n\t" \
		RSEQ_INJECT_ASM(5) \
		"movq $0, %[rseq_cs]\n\t" \
		_teardown \
		".pushsection __rseq_failure, \"a\"\n\t" \
		"4:\n\t" \
		"movq $0, %[rseq_cs]\n\t" \
		_teardown \
		"jmp %l[failure]\n\t" \
		".popsection\n\t" \
		: /* gcc asm goto does not allow outputs */ \
		: [start_event_counter]"r"((_start_value).event_counter), \
		  [current_event_counter]"m"((_start_value).rseqp->u.e.event_counter), \
		  [rseq_cs]"m"((_start_value).rseqp->rseq_cs) \
		  _spec_input \
		  _final_input \
		  RSEQ_INJECT_INPUT \
		: "memory", "cc", "rax" \
		  _extra_clobber \
		  RSEQ_INJECT_CLOBBER \
		: _failure \
	); \
} while (0)

#define RSEQ_FINISH_FINAL_STORE_ASM() \
		"movq %[to_write_final], %[target_final]\n\t"

/* x86-64 is TSO */
#define RSEQ_FINISH_FINAL_STORE_RELEASE_ASM() \
		RSEQ_FINISH_FINAL_STORE_ASM()

#define RSEQ_FINISH_FINAL_STORE_INPUT(_target_final, _to_write_final) \
		, [to_write_final]"r"(_to_write_final), \
		[target_final]"m"(*(_target_final))

#define RSEQ_FINISH_SPECULATIVE_STORE_ASM() \
		"movq %[to_write_spec], %[target_spec]\n\t" \
		RSEQ_INJECT_ASM(4)

#define RSEQ_FINISH_SPECULATIVE_STORE_INPUT(_target_spec, _to_write_spec) \
		, [to_write_spec]"r"(_to_write_spec), \
		[target_spec]"m"(*(_target_spec))

/* TODO: implement a faster memcpy. */
#define RSEQ_FINISH_MEMCPY_STORE_ASM() \
		"test %[len_memcpy], %[len_memcpy]\n\t" \
		"jz 333f\n\t" \
		"222:\n\t" \
		"movb (%[to_write_memcpy]), %%al\n\t" \
		"movb %%al, (%[target_memcpy])\n\t" \
		"inc %[to_write_memcpy]\n\t" \
		"inc %[target_memcpy]\n\t" \
		"dec %[len_memcpy]\n\t" \
		"jnz 222b\n\t" \
		"333:\n\t" \
		RSEQ_INJECT_ASM(4)

#define RSEQ_FINISH_MEMCPY_STORE_INPUT(_target_memcpy, _to_write_memcpy, _len_memcpy) \
		, [to_write_memcpy]"r"(_to_write_memcpy), \
		[target_memcpy]"r"(_target_memcpy), \
		[len_memcpy]"r"(_len_memcpy), \
		[rseq_scratch0]"m"(rseq_scratch[0]), \
		[rseq_scratch1]"m"(rseq_scratch[1]), \
		[rseq_scratch2]"m"(rseq_scratch[2])

#define RSEQ_FINISH_MEMCPY_CLOBBER()	\
		, "rax"

#define RSEQ_FINISH_MEMCPY_SCRATCH() \
		uint64_t rseq_scratch[3];

/*
 * We need to save and restore those input registers so they can be
 * modified within the assembly.
 */
#define RSEQ_FINISH_MEMCPY_SETUP() \
		"movq %[to_write_memcpy], %[rseq_scratch0]\n\t" \
		"movq %[target_memcpy], %[rseq_scratch1]\n\t" \
		"movq %[len_memcpy], %[rseq_scratch2]\n\t"

#define RSEQ_FINISH_MEMCPY_TEARDOWN() \
		"movq %[rseq_scratch2], %[len_memcpy]\n\t" \
		"movq %[rseq_scratch1], %[target_memcpy]\n\t" \
		"movq %[rseq_scratch0], %[to_write_memcpy]\n\t"

#elif __i386__

/*
 * Support older 32-bit architectures that do not implement fence
 * instructions.
 */
#define smp_mb()	\
	__asm__ __volatile__ ("lock; addl $0,0(%%esp)" : : : "memory")
#define smp_rmb()	\
	__asm__ __volatile__ ("lock; addl $0,0(%%esp)" : : : "memory")
#define smp_wmb()	\
	__asm__ __volatile__ ("lock; addl $0,0(%%esp)" : : : "memory")

#define smp_load_acquire(p)						\
__extension__ ({							\
	__typeof(*p) ____p1 = READ_ONCE(*p);				\
	smp_mb();							\
	____p1;								\
})

#define smp_acquire__after_ctrl_dep()	smp_rmb()

#define smp_store_release(p, v)						\
do {									\
	smp_mb();							\
	WRITE_ONCE(*p, v);						\
} while (0)

#define has_fast_acquire_release()	0
#define has_single_copy_load_64()	0

/*
 * Use eax as scratch register and take memory operands as input to
 * lessen register pressure. Especially needed when compiling
 * do_rseq_memcpy() in O0.
 */
#define RSEQ_FINISH_ASM(_target_final, _to_write_final, _start_value, \
		_failure, _spec_store, _spec_input, \
		_final_store, _final_input, _extra_clobber, \
		_setup, _teardown, _scratch) \
do { \
	_scratch \
	__asm__ __volatile__ goto ( \
		".pushsection __rseq_table, \"aw\"\n\t" \
		".balign 32\n\t" \
		"3:\n\t" \
		".long 1f, 0x0, 2f, 0x0, 4f, 0x0, 0x0, 0x0\n\t" \
		".popsection\n\t" \
		"1:\n\t" \
		_setup \
		RSEQ_INJECT_ASM(1) \
		"movl $3b, %[rseq_cs]\n\t" \
		RSEQ_INJECT_ASM(2) \
		"movl %[start_event_counter], %%eax\n\t" \
		"cmpl %%eax, %[current_event_counter]\n\t" \
		"jnz 4f\n\t" \
		RSEQ_INJECT_ASM(3) \
		_spec_store \
		_final_store \
		"2:\n\t" \
		RSEQ_INJECT_ASM(5) \
		"movl $0, %[rseq_cs]\n\t" \
		_teardown \
		".pushsection __rseq_failure, \"a\"\n\t" \
		"4:\n\t" \
		"movl $0, %[rseq_cs]\n\t" \
		_teardown \
		"jmp %l[failure]\n\t" \
		".popsection\n\t" \
		: /* gcc asm goto does not allow outputs */ \
		: [start_event_counter]"m"((_start_value).event_counter), \
		  [current_event_counter]"m"((_start_value).rseqp->u.e.event_counter), \
		  [rseq_cs]"m"((_start_value).rseqp->rseq_cs) \
		  _spec_input \
		  _final_input \
		  RSEQ_INJECT_INPUT \
		: "memory", "cc", "eax" \
		  _extra_clobber \
		  RSEQ_INJECT_CLOBBER \
		: _failure \
	); \
} while (0)

#define RSEQ_FINISH_FINAL_STORE_ASM() \
		"movl %[to_write_final], %%eax\n\t" \
		"movl %%eax, %[target_final]\n\t"

#define RSEQ_FINISH_FINAL_STORE_RELEASE_ASM() \
		"lock; addl $0,0(%%esp)\n\t" \
		RSEQ_FINISH_FINAL_STORE_ASM()

#define RSEQ_FINISH_FINAL_STORE_INPUT(_target_final, _to_write_final) \
		, [to_write_final]"m"(_to_write_final), \
		[target_final]"m"(*(_target_final))

#define RSEQ_FINISH_SPECULATIVE_STORE_ASM() \
		"movl %[to_write_spec], %%eax\n\t" \
		"movl %%eax, %[target_spec]\n\t" \
		RSEQ_INJECT_ASM(4)

#define RSEQ_FINISH_SPECULATIVE_STORE_INPUT(_target_spec, _to_write_spec) \
		, [to_write_spec]"m"(_to_write_spec), \
		[target_spec]"m"(*(_target_spec))

/* TODO: implement a faster memcpy. */
#define RSEQ_FINISH_MEMCPY_STORE_ASM() \
		"movl %[len_memcpy], %%eax\n\t" \
		"test %%eax, %%eax\n\t" \
		"jz 333f\n\t" \
		"222:\n\t" \
		"movb (%[to_write_memcpy]), %%al\n\t" \
		"movb %%al, (%[target_memcpy])\n\t" \
		"inc %[to_write_memcpy]\n\t" \
		"inc %[target_memcpy]\n\t" \
		"decl %[rseq_scratch2]\n\t" \
		"jnz 222b\n\t" \
		"333:\n\t" \
		RSEQ_INJECT_ASM(4)

#define RSEQ_FINISH_MEMCPY_STORE_INPUT(_target_memcpy, _to_write_memcpy, _len_memcpy) \
		, [to_write_memcpy]"r"(_to_write_memcpy), \
		[target_memcpy]"r"(_target_memcpy), \
		[len_memcpy]"m"(_len_memcpy), \
		[rseq_scratch0]"m"(rseq_scratch[0]), \
		[rseq_scratch1]"m"(rseq_scratch[1]), \
		[rseq_scratch2]"m"(rseq_scratch[2])

#define RSEQ_FINISH_MEMCPY_CLOBBER()

#define RSEQ_FINISH_MEMCPY_SCRATCH() \
		uint32_t rseq_scratch[3];

/*
 * We need to save and restore those input registers so they can be
 * modified within the assembly.
 */
#define RSEQ_FINISH_MEMCPY_SETUP() \
		"movl %[to_write_memcpy], %[rseq_scratch0]\n\t" \
		"movl %[target_memcpy], %[rseq_scratch1]\n\t" \
		"movl %[len_memcpy], %%eax\n\t" \
		"movl %%eax, %[rseq_scratch2]\n\t"

#define RSEQ_FINISH_MEMCPY_TEARDOWN() \
		"movl %[rseq_scratch1], %[target_memcpy]\n\t" \
		"movl %[rseq_scratch0], %[to_write_memcpy]\n\t"

#endif
Commit	Line	Data
b54c5158 MD	1	/*
	2	* rseq-x86.h
	3	*
	4	* (C) Copyright 2016 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	5	*
	6	* Permission is hereby granted, free of charge, to any person obtaining a copy
	7	* of this software and associated documentation files (the "Software"), to deal
	8	* in the Software without restriction, including without limitation the rights
	9	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	10	* copies of the Software, and to permit persons to whom the Software is
	11	* furnished to do so, subject to the following conditions:
	12	*
	13	* The above copyright notice and this permission notice shall be included in
	14	* all copies or substantial portions of the Software.
	15	*
	16	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	17	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	18	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
	19	* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	20	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	21	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
	22	* SOFTWARE.
	23	*/
	24
	25	#ifdef __x86_64__
	26
	27	#define smp_mb() __asm__ __volatile__ ("mfence" : : : "memory")
	28	#define smp_rmb() barrier()
	29	#define smp_wmb() barrier()
	30
	31	#define smp_load_acquire(p) \
	32	__extension__ ({ \
	33	__typeof(p) ____p1 = READ_ONCE(p); \
	34	barrier(); \
	35	____p1; \
	36	})
	37
	38	#define smp_acquire__after_ctrl_dep() smp_rmb()
	39
	40	#define smp_store_release(p, v) \
	41	do { \
	42	barrier(); \
	43	WRITE_ONCE(*p, v); \
	44	} while (0)
	45
	46	#define has_fast_acquire_release() 1
	47	#define has_single_copy_load_64() 1
	48
	49	/*
	50	* The __rseq_table section can be used by debuggers to better handle
	51	* single-stepping through the restartable critical sections.
	52	*/
	53	#define RSEQ_FINISH_ASM(_target_final, _to_write_final, _start_value, \
	54	_failure, _spec_store, _spec_input, \
	55	_final_store, _final_input, _extra_clobber, \
	56	_setup, _teardown, _scratch) \
	57	do { \
	58	_scratch \
	59	__asm__ __volatile__ goto ( \
	60	".pushsection __rseq_table, \"aw\"\n\t" \
	61	".balign 32\n\t" \
	62	"3:\n\t" \
	63	".quad 1f, 2f, 4f, 0x0\n\t" \
	64	".popsection\n\t" \
65	"1:\n\t" \
66	_setup \
67	RSEQ_INJECT_ASM(1) \
f88ff702 MD	68	"leaq 3b(%%rip), %%rax\n\t" \
f88ff702 MD	69	"movq %%rax, %[rseq_cs]\n\t" \
b54c5158 MD	70	RSEQ_INJECT_ASM(2) \
	71	"cmpl %[start_event_counter], %[current_event_counter]\n\t" \
	72	"jnz 4f\n\t" \
	73	RSEQ_INJECT_ASM(3) \
	74	_spec_store \
	75	_final_store \
	76	"2:\n\t" \
	77	RSEQ_INJECT_ASM(5) \
	78	"movq $0, %[rseq_cs]\n\t" \
	79	_teardown \
	80	".pushsection __rseq_failure, \"a\"\n\t" \
	81	"4:\n\t" \
	82	"movq $0, %[rseq_cs]\n\t" \
	83	_teardown \
	84	"jmp %l[failure]\n\t" \
	85	".popsection\n\t" \
	86	: /* gcc asm goto does not allow outputs */ \
	87	: [start_event_counter]"r"((_start_value).event_counter), \
	88	[current_event_counter]"m"((_start_value).rseqp->u.e.event_counter), \
	89	[rseq_cs]"m"((_start_value).rseqp->rseq_cs) \
	90	_spec_input \
	91	_final_input \
	92	RSEQ_INJECT_INPUT \
f88ff702	93	: "memory", "cc", "rax" \
b54c5158 MD	94	_extra_clobber \
	95	RSEQ_INJECT_CLOBBER \
	96	: _failure \
	97	); \
	98	} while (0)
	99
	100	#define RSEQ_FINISH_FINAL_STORE_ASM() \
	101	"movq %[to_write_final], %[target_final]\n\t"
	102
	103	/* x86-64 is TSO */
	104	#define RSEQ_FINISH_FINAL_STORE_RELEASE_ASM() \
	105	RSEQ_FINISH_FINAL_STORE_ASM()
	106
	107	#define RSEQ_FINISH_FINAL_STORE_INPUT(_target_final, _to_write_final) \
	108	, [to_write_final]"r"(_to_write_final), \
	109	[target_final]"m"(*(_target_final))
	110
	111	#define RSEQ_FINISH_SPECULATIVE_STORE_ASM() \
	112	"movq %[to_write_spec], %[target_spec]\n\t" \
	113	RSEQ_INJECT_ASM(4)
	114
	115	#define RSEQ_FINISH_SPECULATIVE_STORE_INPUT(_target_spec, _to_write_spec) \
	116	, [to_write_spec]"r"(_to_write_spec), \
	117	[target_spec]"m"(*(_target_spec))
	118
	119	/* TODO: implement a faster memcpy. */
	120	#define RSEQ_FINISH_MEMCPY_STORE_ASM() \
	121	"test %[len_memcpy], %[len_memcpy]\n\t" \
	122	"jz 333f\n\t" \
	123	"222:\n\t" \
	124	"movb (%[to_write_memcpy]), %%al\n\t" \
	125	"movb %%al, (%[target_memcpy])\n\t" \
	126	"inc %[to_write_memcpy]\n\t" \
	127	"inc %[target_memcpy]\n\t" \
	128	"dec %[len_memcpy]\n\t" \
	129	"jnz 222b\n\t" \
	130	"333:\n\t" \
	131	RSEQ_INJECT_ASM(4)
	132
	133	#define RSEQ_FINISH_MEMCPY_STORE_INPUT(_target_memcpy, _to_write_memcpy, _len_memcpy) \
	134	, [to_write_memcpy]"r"(_to_write_memcpy), \
	135	[target_memcpy]"r"(_target_memcpy), \
	136	[len_memcpy]"r"(_len_memcpy), \
	137	[rseq_scratch0]"m"(rseq_scratch[0]), \
	138	[rseq_scratch1]"m"(rseq_scratch[1]), \
	139	[rseq_scratch2]"m"(rseq_scratch[2])
	140
	141	#define RSEQ_FINISH_MEMCPY_CLOBBER() \
	142	, "rax"
	143
	144	#define RSEQ_FINISH_MEMCPY_SCRATCH() \
	145	uint64_t rseq_scratch[3];
	146
	147	/*
	148	* We need to save and restore those input registers so they can be
	149	* modified within the assembly.
	150	*/
	151	#define RSEQ_FINISH_MEMCPY_SETUP() \
	152	"movq %[to_write_memcpy], %[rseq_scratch0]\n\t" \
	153	"movq %[target_memcpy], %[rseq_scratch1]\n\t" \
	154	"movq %[len_memcpy], %[rseq_scratch2]\n\t"
	155
	156	#define RSEQ_FINISH_MEMCPY_TEARDOWN() \
	157	"movq %[rseq_scratch2], %[len_memcpy]\n\t" \
158	"movq %[rseq_scratch1], %[target_memcpy]\n\t" \
159	"movq %[rseq_scratch0], %[to_write_memcpy]\n\t"
160
161	#elif __i386__
162
163	/*
164	* Support older 32-bit architectures that do not implement fence
165	* instructions.
166	*/
167	#define smp_mb() \
168	__asm__ __volatile__ ("lock; addl $0,0(%%esp)" : : : "memory")
169	#define smp_rmb() \
170	__asm__ __volatile__ ("lock; addl $0,0(%%esp)" : : : "memory")
171	#define smp_wmb() \
172	__asm__ __volatile__ ("lock; addl $0,0(%%esp)" : : : "memory")
173
174	#define smp_load_acquire(p) \
175	__extension__ ({ \
176	__typeof(p) ____p1 = READ_ONCE(p); \
177	smp_mb(); \
178	____p1; \
179	})
180
181	#define smp_acquire__after_ctrl_dep() smp_rmb()
182
183	#define smp_store_release(p, v) \
184	do { \
185	smp_mb(); \
186	WRITE_ONCE(*p, v); \
187	} while (0)
188
189	#define has_fast_acquire_release() 0
190	#define has_single_copy_load_64() 0
191
192	/*
193	* Use eax as scratch register and take memory operands as input to
194	* lessen register pressure. Especially needed when compiling
195	* do_rseq_memcpy() in O0.
196	*/
197	#define RSEQ_FINISH_ASM(_target_final, _to_write_final, _start_value, \
198	_failure, _spec_store, _spec_input, \
199	_final_store, _final_input, _extra_clobber, \
200	_setup, _teardown, _scratch) \
201	do { \
202	_scratch \
203	__asm__ __volatile__ goto ( \
204	".pushsection __rseq_table, \"aw\"\n\t" \
205	".balign 32\n\t" \
206	"3:\n\t" \
207	".long 1f, 0x0, 2f, 0x0, 4f, 0x0, 0x0, 0x0\n\t" \
208	".popsection\n\t" \
209	"1:\n\t" \
210	_setup \
211	RSEQ_INJECT_ASM(1) \
212	"movl $3b, %[rseq_cs]\n\t" \
213	RSEQ_INJECT_ASM(2) \
214	"movl %[start_event_counter], %%eax\n\t" \
215	"cmpl %%eax, %[current_event_counter]\n\t" \
216	"jnz 4f\n\t" \
217	RSEQ_INJECT_ASM(3) \
218	_spec_store \
219	_final_store \
220	"2:\n\t" \
221	RSEQ_INJECT_ASM(5) \
222	"movl $0, %[rseq_cs]\n\t" \
223	_teardown \
224	".pushsection __rseq_failure, \"a\"\n\t" \
225	"4:\n\t" \
226	"movl $0, %[rseq_cs]\n\t" \
227	_teardown \
228	"jmp %l[failure]\n\t" \
229	".popsection\n\t" \
230	: /* gcc asm goto does not allow outputs */ \
231	: [start_event_counter]"m"((_start_value).event_counter), \
232	[current_event_counter]"m"((_start_value).rseqp->u.e.event_counter), \
233	[rseq_cs]"m"((_start_value).rseqp->rseq_cs) \
234	_spec_input \
235	_final_input \
236	RSEQ_INJECT_INPUT \
237	: "memory", "cc", "eax" \
238	_extra_clobber \
239	RSEQ_INJECT_CLOBBER \
240	: _failure \
241	); \
242	} while (0)
243
244	#define RSEQ_FINISH_FINAL_STORE_ASM() \
245	"movl %[to_write_final], %%eax\n\t" \
246	"movl %%eax, %[target_final]\n\t"
247
248	#define RSEQ_FINISH_FINAL_STORE_RELEASE_ASM() \
249	"lock; addl $0,0(%%esp)\n\t" \
250	RSEQ_FINISH_FINAL_STORE_ASM()
251
252	#define RSEQ_FINISH_FINAL_STORE_INPUT(_target_final, _to_write_final) \
253	, [to_write_final]"m"(_to_write_final), \
254	[target_final]"m"(*(_target_final))
255
256	#define RSEQ_FINISH_SPECULATIVE_STORE_ASM() \
257	"movl %[to_write_spec], %%eax\n\t" \
258	"movl %%eax, %[target_spec]\n\t" \
259	RSEQ_INJECT_ASM(4)
260
261	#define RSEQ_FINISH_SPECULATIVE_STORE_INPUT(_target_spec, _to_write_spec) \
262	, [to_write_spec]"m"(_to_write_spec), \
263	[target_spec]"m"(*(_target_spec))
264
265	/* TODO: implement a faster memcpy. */
266	#define RSEQ_FINISH_MEMCPY_STORE_ASM() \
267	"movl %[len_memcpy], %%eax\n\t" \
268	"test %%eax, %%eax\n\t" \
269	"jz 333f\n\t" \
270	"222:\n\t" \
271	"movb (%[to_write_memcpy]), %%al\n\t" \
272	"movb %%al, (%[target_memcpy])\n\t" \
273	"inc %[to_write_memcpy]\n\t" \
274	"inc %[target_memcpy]\n\t" \
275	"decl %[rseq_scratch2]\n\t" \
276	"jnz 222b\n\t" \
277	"333:\n\t" \
278	RSEQ_INJECT_ASM(4)
279
280	#define RSEQ_FINISH_MEMCPY_STORE_INPUT(_target_memcpy, _to_write_memcpy, _len_memcpy) \
281	, [to_write_memcpy]"r"(_to_write_memcpy), \
282	[target_memcpy]"r"(_target_memcpy), \
283	[len_memcpy]"m"(_len_memcpy), \
284	[rseq_scratch0]"m"(rseq_scratch[0]), \
285	[rseq_scratch1]"m"(rseq_scratch[1]), \
286	[rseq_scratch2]"m"(rseq_scratch[2])
287
288	#define RSEQ_FINISH_MEMCPY_CLOBBER()
289
290	#define RSEQ_FINISH_MEMCPY_SCRATCH() \
291	uint32_t rseq_scratch[3];
292
293	/*
294	* We need to save and restore those input registers so they can be
295	* modified within the assembly.
296	*/
297	#define RSEQ_FINISH_MEMCPY_SETUP() \
298	"movl %[to_write_memcpy], %[rseq_scratch0]\n\t" \
299	"movl %[target_memcpy], %[rseq_scratch1]\n\t" \
300	"movl %[len_memcpy], %%eax\n\t" \
301	"movl %%eax, %[rseq_scratch2]\n\t"
302
303	#define RSEQ_FINISH_MEMCPY_TEARDOWN() \
304	"movl %[rseq_scratch1], %[target_memcpy]\n\t" \
305	"movl %[rseq_scratch0], %[to_write_memcpy]\n\t"
306
307	#endif