1/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
2
3/*
4 * RSEQ_SIG uses the trap4 instruction. As Linux does not make use of the
5 * access-register mode nor the linkage stack this instruction will always
6 * cause a special-operation exception (the trap-enabled bit in the DUCT
7 * is and will stay 0). The instruction pattern is
8 *	b2 ff 0f ff	trap4	4095(%r0)
9 */
10#define RSEQ_SIG	0xB2FF0FFF
11
12#define rseq_smp_mb()	__asm__ __volatile__ ("bcr 15,0" ::: "memory")
13#define rseq_smp_rmb()	rseq_smp_mb()
14#define rseq_smp_wmb()	rseq_smp_mb()
15
16#define rseq_smp_load_acquire(p)					\
17__extension__ ({							\
18	__typeof(*p) ____p1 = RSEQ_READ_ONCE(*p);			\
19	rseq_barrier();							\
20	____p1;								\
21})
22
23#define rseq_smp_acquire__after_ctrl_dep()	rseq_smp_rmb()
24
25#define rseq_smp_store_release(p, v)					\
26do {									\
27	rseq_barrier();							\
28	RSEQ_WRITE_ONCE(*p, v);						\
29} while (0)
30
31#ifdef RSEQ_SKIP_FASTPATH
32#include "rseq-skip.h"
33#else /* !RSEQ_SKIP_FASTPATH */
34
35#ifdef __s390x__
36
37#define LONG_L			"lg"
38#define LONG_S			"stg"
39#define LONG_LT_R		"ltgr"
40#define LONG_CMP		"cg"
41#define LONG_CMP_R		"cgr"
42#define LONG_ADDI		"aghi"
43#define LONG_ADD_R		"agr"
44
45#define __RSEQ_ASM_DEFINE_TABLE(label, version, flags,			\
46				start_ip, post_commit_offset, abort_ip)	\
47		".pushsection __rseq_cs, \"aw\"\n\t"			\
48		".balign 32\n\t"					\
49		__rseq_str(label) ":\n\t"				\
50		".long " __rseq_str(version) ", " __rseq_str(flags) "\n\t" \
51		".quad " __rseq_str(start_ip) ", " __rseq_str(post_commit_offset) ", " __rseq_str(abort_ip) "\n\t" \
52		".popsection\n\t"					\
53		".pushsection __rseq_cs_ptr_array, \"aw\"\n\t"		\
54		".quad " __rseq_str(label) "b\n\t"			\
55		".popsection\n\t"
56
57/*
58 * Exit points of a rseq critical section consist of all instructions outside
59 * of the critical section where a critical section can either branch to or
60 * reach through the normal course of its execution. The abort IP and the
61 * post-commit IP are already part of the __rseq_cs section and should not be
62 * explicitly defined as additional exit points. Knowing all exit points is
63 * useful to assist debuggers stepping over the critical section.
64 */
65#define RSEQ_ASM_DEFINE_EXIT_POINT(start_ip, exit_ip)			\
66		".pushsection __rseq_exit_point_array, \"aw\"\n\t"	\
67		".quad " __rseq_str(start_ip) ", " __rseq_str(exit_ip) "\n\t" \
68		".popsection\n\t"
69
70#elif __s390__
71
72#define __RSEQ_ASM_DEFINE_TABLE(label, version, flags,			\
73				start_ip, post_commit_offset, abort_ip)	\
74		".pushsection __rseq_cs, \"aw\"\n\t"			\
75		".balign 32\n\t"					\
76		__rseq_str(label) ":\n\t"				\
77		".long " __rseq_str(version) ", " __rseq_str(flags) "\n\t" \
78		".long 0x0, " __rseq_str(start_ip) ", 0x0, " __rseq_str(post_commit_offset) ", 0x0, " __rseq_str(abort_ip) "\n\t" \
79		".popsection\n\t"					\
80		".pushsection __rseq_cs_ptr_array, \"aw\"\n\t"		\
81		".long 0x0, " __rseq_str(label) "b\n\t"			\
82		".popsection\n\t"
83
84/*
85 * Exit points of a rseq critical section consist of all instructions outside
86 * of the critical section where a critical section can either branch to or
87 * reach through the normal course of its execution. The abort IP and the
88 * post-commit IP are already part of the __rseq_cs section and should not be
89 * explicitly defined as additional exit points. Knowing all exit points is
90 * useful to assist debuggers stepping over the critical section.
91 */
92#define RSEQ_ASM_DEFINE_EXIT_POINT(start_ip, exit_ip)			\
93		".pushsection __rseq_exit_point_array, \"aw\"\n\t"	\
94		".long 0x0, " __rseq_str(start_ip) ", 0x0, " __rseq_str(exit_ip) "\n\t" \
95		".popsection\n\t"
96
97#define LONG_L			"l"
98#define LONG_S			"st"
99#define LONG_LT_R		"ltr"
100#define LONG_CMP		"c"
101#define LONG_CMP_R		"cr"
102#define LONG_ADDI		"ahi"
103#define LONG_ADD_R		"ar"
104
105#endif
106
107#define RSEQ_ASM_DEFINE_TABLE(label, start_ip, post_commit_ip, abort_ip) \
108	__RSEQ_ASM_DEFINE_TABLE(label, 0x0, 0x0, start_ip,		\
109				(post_commit_ip - start_ip), abort_ip)
110
111#define RSEQ_ASM_STORE_RSEQ_CS(label, cs_label, rseq_cs)		\
112		RSEQ_INJECT_ASM(1)					\
113		"larl %%r0, " __rseq_str(cs_label) "\n\t"		\
114		LONG_S " %%r0, %[" __rseq_str(rseq_cs) "]\n\t"		\
115		__rseq_str(label) ":\n\t"
116
117#define RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, label)		\
118		RSEQ_INJECT_ASM(2)					\
119		"c %[" __rseq_str(cpu_id) "], %[" __rseq_str(current_cpu_id) "]\n\t" \
120		"jnz " __rseq_str(label) "\n\t"
121
122#define RSEQ_ASM_DEFINE_ABORT(label, teardown, abort_label)		\
123		".pushsection __rseq_failure, \"ax\"\n\t"		\
124		".long " __rseq_str(RSEQ_SIG) "\n\t"			\
125		__rseq_str(label) ":\n\t"				\
126		teardown						\
127		"jg %l[" __rseq_str(abort_label) "]\n\t"		\
128		".popsection\n\t"
129
130#define RSEQ_ASM_DEFINE_CMPFAIL(label, teardown, cmpfail_label)		\
131		".pushsection __rseq_failure, \"ax\"\n\t"		\
132		__rseq_str(label) ":\n\t"				\
133		teardown						\
134		"jg %l[" __rseq_str(cmpfail_label) "]\n\t"		\
135		".popsection\n\t"
136
137static inline __attribute__((always_inline))
138int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
139{
140	RSEQ_INJECT_C(9)
141
142	__asm__ __volatile__ goto (
143		RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */
144		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
145#ifdef RSEQ_COMPARE_TWICE
146		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
147		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2])
148#endif
149		/* Start rseq by storing table entry pointer into rseq_cs. */
150		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, rseq_cs)
151		RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
152		RSEQ_INJECT_ASM(3)
153		LONG_CMP " %[expect], %[v]\n\t"
154		"jnz %l[cmpfail]\n\t"
155		RSEQ_INJECT_ASM(4)
156#ifdef RSEQ_COMPARE_TWICE
157		RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1])
158		LONG_CMP " %[expect], %[v]\n\t"
159		"jnz %l[error2]\n\t"
160#endif
161		/* final store */
162		LONG_S " %[newv], %[v]\n\t"
163		"2:\n\t"
164		RSEQ_INJECT_ASM(5)
165		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
166		: /* gcc asm goto does not allow outputs */
167		: [cpu_id]		"r" (cpu),
168		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
169		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
170		  [v]			"m" (*v),
171		  [expect]		"r" (expect),
172		  [newv]		"r" (newv)
173		  RSEQ_INJECT_INPUT
174		: "memory", "cc", "r0"
175		  RSEQ_INJECT_CLOBBER
176		: abort, cmpfail
177#ifdef RSEQ_COMPARE_TWICE
178		  , error1, error2
179#endif
180	);
181	rseq_after_asm_goto();
182	return 0;
183abort:
184	rseq_after_asm_goto();
185	RSEQ_INJECT_FAILED
186	return -1;
187cmpfail:
188	rseq_after_asm_goto();
189	return 1;
190#ifdef RSEQ_COMPARE_TWICE
191error1:
192	rseq_after_asm_goto();
193	rseq_bug("cpu_id comparison failed");
194error2:
195	rseq_after_asm_goto();
196	rseq_bug("expected value comparison failed");
197#endif
198}
199
200/*
201 * Compare @v against @expectnot. When it does _not_ match, load @v
202 * into @load, and store the content of *@v + voffp into @v.
203 */
204static inline __attribute__((always_inline))
205int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
206			       long voffp, intptr_t *load, int cpu)
207{
208	RSEQ_INJECT_C(9)
209
210	__asm__ __volatile__ goto (
211		RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */
212		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
213#ifdef RSEQ_COMPARE_TWICE
214		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
215		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2])
216#endif
217		/* Start rseq by storing table entry pointer into rseq_cs. */
218		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, rseq_cs)
219		RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
220		RSEQ_INJECT_ASM(3)
221		LONG_L " %%r1, %[v]\n\t"
222		LONG_CMP_R " %%r1, %[expectnot]\n\t"
223		"je %l[cmpfail]\n\t"
224		RSEQ_INJECT_ASM(4)
225#ifdef RSEQ_COMPARE_TWICE
226		RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1])
227		LONG_L " %%r1, %[v]\n\t"
228		LONG_CMP_R " %%r1, %[expectnot]\n\t"
229		"je %l[error2]\n\t"
230#endif
231		LONG_S " %%r1, %[load]\n\t"
232		LONG_ADD_R " %%r1, %[voffp]\n\t"
233		LONG_L " %%r1, 0(%%r1)\n\t"
234		/* final store */
235		LONG_S " %%r1, %[v]\n\t"
236		"2:\n\t"
237		RSEQ_INJECT_ASM(5)
238		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
239		: /* gcc asm goto does not allow outputs */
240		: [cpu_id]		"r" (cpu),
241		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
242		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
243		  /* final store input */
244		  [v]			"m" (*v),
245		  [expectnot]		"r" (expectnot),
246		  [voffp]		"r" (voffp),
247		  [load]		"m" (*load)
248		  RSEQ_INJECT_INPUT
249		: "memory", "cc", "r0", "r1"
250		  RSEQ_INJECT_CLOBBER
251		: abort, cmpfail
252#ifdef RSEQ_COMPARE_TWICE
253		  , error1, error2
254#endif
255	);
256	rseq_after_asm_goto();
257	return 0;
258abort:
259	rseq_after_asm_goto();
260	RSEQ_INJECT_FAILED
261	return -1;
262cmpfail:
263	rseq_after_asm_goto();
264	return 1;
265#ifdef RSEQ_COMPARE_TWICE
266error1:
267	rseq_after_asm_goto();
268	rseq_bug("cpu_id comparison failed");
269error2:
270	rseq_after_asm_goto();
271	rseq_bug("expected value comparison failed");
272#endif
273}
274
275static inline __attribute__((always_inline))
276int rseq_addv(intptr_t *v, intptr_t count, int cpu)
277{
278	RSEQ_INJECT_C(9)
279
280	__asm__ __volatile__ goto (
281		RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */
282#ifdef RSEQ_COMPARE_TWICE
283		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
284#endif
285		/* Start rseq by storing table entry pointer into rseq_cs. */
286		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, rseq_cs)
287		RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
288		RSEQ_INJECT_ASM(3)
289#ifdef RSEQ_COMPARE_TWICE
290		RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1])
291#endif
292		LONG_L " %%r0, %[v]\n\t"
293		LONG_ADD_R " %%r0, %[count]\n\t"
294		/* final store */
295		LONG_S " %%r0, %[v]\n\t"
296		"2:\n\t"
297		RSEQ_INJECT_ASM(4)
298		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
299		: /* gcc asm goto does not allow outputs */
300		: [cpu_id]		"r" (cpu),
301		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
302		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
303		  /* final store input */
304		  [v]			"m" (*v),
305		  [count]		"r" (count)
306		  RSEQ_INJECT_INPUT
307		: "memory", "cc", "r0"
308		  RSEQ_INJECT_CLOBBER
309		: abort
310#ifdef RSEQ_COMPARE_TWICE
311		  , error1
312#endif
313	);
314	rseq_after_asm_goto();
315	return 0;
316abort:
317	rseq_after_asm_goto();
318	RSEQ_INJECT_FAILED
319	return -1;
320#ifdef RSEQ_COMPARE_TWICE
321error1:
322	rseq_after_asm_goto();
323	rseq_bug("cpu_id comparison failed");
324#endif
325}
326
327static inline __attribute__((always_inline))
328int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
329				 intptr_t *v2, intptr_t newv2,
330				 intptr_t newv, int cpu)
331{
332	RSEQ_INJECT_C(9)
333
334	__asm__ __volatile__ goto (
335		RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */
336		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
337#ifdef RSEQ_COMPARE_TWICE
338		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
339		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2])
340#endif
341		/* Start rseq by storing table entry pointer into rseq_cs. */
342		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, rseq_cs)
343		RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
344		RSEQ_INJECT_ASM(3)
345		LONG_CMP " %[expect], %[v]\n\t"
346		"jnz %l[cmpfail]\n\t"
347		RSEQ_INJECT_ASM(4)
348#ifdef RSEQ_COMPARE_TWICE
349		RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1])
350		LONG_CMP " %[expect], %[v]\n\t"
351		"jnz %l[error2]\n\t"
352#endif
353		/* try store */
354		LONG_S " %[newv2], %[v2]\n\t"
355		RSEQ_INJECT_ASM(5)
356		/* final store */
357		LONG_S " %[newv], %[v]\n\t"
358		"2:\n\t"
359		RSEQ_INJECT_ASM(6)
360		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
361		: /* gcc asm goto does not allow outputs */
362		: [cpu_id]		"r" (cpu),
363		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
364		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
365		  /* try store input */
366		  [v2]			"m" (*v2),
367		  [newv2]		"r" (newv2),
368		  /* final store input */
369		  [v]			"m" (*v),
370		  [expect]		"r" (expect),
371		  [newv]		"r" (newv)
372		  RSEQ_INJECT_INPUT
373		: "memory", "cc", "r0"
374		  RSEQ_INJECT_CLOBBER
375		: abort, cmpfail
376#ifdef RSEQ_COMPARE_TWICE
377		  , error1, error2
378#endif
379	);
380	rseq_after_asm_goto();
381	return 0;
382abort:
383	rseq_after_asm_goto();
384	RSEQ_INJECT_FAILED
385	return -1;
386cmpfail:
387	rseq_after_asm_goto();
388	return 1;
389#ifdef RSEQ_COMPARE_TWICE
390error1:
391	rseq_after_asm_goto();
392	rseq_bug("cpu_id comparison failed");
393error2:
394	rseq_after_asm_goto();
395	rseq_bug("expected value comparison failed");
396#endif
397}
398
399/* s390 is TSO. */
400static inline __attribute__((always_inline))
401int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect,
402					 intptr_t *v2, intptr_t newv2,
403					 intptr_t newv, int cpu)
404{
405	return rseq_cmpeqv_trystorev_storev(v, expect, v2, newv2, newv, cpu);
406}
407
408static inline __attribute__((always_inline))
409int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
410			      intptr_t *v2, intptr_t expect2,
411			      intptr_t newv, int cpu)
412{
413	RSEQ_INJECT_C(9)
414
415	__asm__ __volatile__ goto (
416		RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */
417		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
418#ifdef RSEQ_COMPARE_TWICE
419		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
420		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2])
421		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error3])
422#endif
423		/* Start rseq by storing table entry pointer into rseq_cs. */
424		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, rseq_cs)
425		RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
426		RSEQ_INJECT_ASM(3)
427		LONG_CMP " %[expect], %[v]\n\t"
428		"jnz %l[cmpfail]\n\t"
429		RSEQ_INJECT_ASM(4)
430		LONG_CMP " %[expect2], %[v2]\n\t"
431		"jnz %l[cmpfail]\n\t"
432		RSEQ_INJECT_ASM(5)
433#ifdef RSEQ_COMPARE_TWICE
434		RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1])
435		LONG_CMP " %[expect], %[v]\n\t"
436		"jnz %l[error2]\n\t"
437		LONG_CMP " %[expect2], %[v2]\n\t"
438		"jnz %l[error3]\n\t"
439#endif
440		/* final store */
441		LONG_S " %[newv], %[v]\n\t"
442		"2:\n\t"
443		RSEQ_INJECT_ASM(6)
444		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
445		: /* gcc asm goto does not allow outputs */
446		: [cpu_id]		"r" (cpu),
447		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
448		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
449		  /* cmp2 input */
450		  [v2]			"m" (*v2),
451		  [expect2]		"r" (expect2),
452		  /* final store input */
453		  [v]			"m" (*v),
454		  [expect]		"r" (expect),
455		  [newv]		"r" (newv)
456		  RSEQ_INJECT_INPUT
457		: "memory", "cc", "r0"
458		  RSEQ_INJECT_CLOBBER
459		: abort, cmpfail
460#ifdef RSEQ_COMPARE_TWICE
461		  , error1, error2, error3
462#endif
463	);
464	rseq_after_asm_goto();
465	return 0;
466abort:
467	rseq_after_asm_goto();
468	RSEQ_INJECT_FAILED
469	return -1;
470cmpfail:
471	rseq_after_asm_goto();
472	return 1;
473#ifdef RSEQ_COMPARE_TWICE
474error1:
475	rseq_after_asm_goto();
476	rseq_bug("cpu_id comparison failed");
477error2:
478	rseq_after_asm_goto();
479	rseq_bug("1st expected value comparison failed");
480error3:
481	rseq_after_asm_goto();
482	rseq_bug("2nd expected value comparison failed");
483#endif
484}
485
486static inline __attribute__((always_inline))
487int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
488				 void *dst, void *src, size_t len,
489				 intptr_t newv, int cpu)
490{
491	uint64_t rseq_scratch[3];
492
493	RSEQ_INJECT_C(9)
494
495	__asm__ __volatile__ goto (
496		RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */
497		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
498#ifdef RSEQ_COMPARE_TWICE
499		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
500		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2])
501#endif
502		LONG_S " %[src], %[rseq_scratch0]\n\t"
503		LONG_S " %[dst], %[rseq_scratch1]\n\t"
504		LONG_S " %[len], %[rseq_scratch2]\n\t"
505		/* Start rseq by storing table entry pointer into rseq_cs. */
506		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, rseq_cs)
507		RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
508		RSEQ_INJECT_ASM(3)
509		LONG_CMP " %[expect], %[v]\n\t"
510		"jnz 5f\n\t"
511		RSEQ_INJECT_ASM(4)
512#ifdef RSEQ_COMPARE_TWICE
513		RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 6f)
514		LONG_CMP " %[expect], %[v]\n\t"
515		"jnz 7f\n\t"
516#endif
517		/* try memcpy */
518		LONG_LT_R " %[len], %[len]\n\t"
519		"jz 333f\n\t"
520		"222:\n\t"
521		"ic %%r0,0(%[src])\n\t"
522		"stc %%r0,0(%[dst])\n\t"
523		LONG_ADDI " %[src], 1\n\t"
524		LONG_ADDI " %[dst], 1\n\t"
525		LONG_ADDI " %[len], -1\n\t"
526		"jnz 222b\n\t"
527		"333:\n\t"
528		RSEQ_INJECT_ASM(5)
529		/* final store */
530		LONG_S " %[newv], %[v]\n\t"
531		"2:\n\t"
532		RSEQ_INJECT_ASM(6)
533		/* teardown */
534		LONG_L " %[len], %[rseq_scratch2]\n\t"
535		LONG_L " %[dst], %[rseq_scratch1]\n\t"
536		LONG_L " %[src], %[rseq_scratch0]\n\t"
537		RSEQ_ASM_DEFINE_ABORT(4,
538			LONG_L " %[len], %[rseq_scratch2]\n\t"
539			LONG_L " %[dst], %[rseq_scratch1]\n\t"
540			LONG_L " %[src], %[rseq_scratch0]\n\t",
541			abort)
542		RSEQ_ASM_DEFINE_CMPFAIL(5,
543			LONG_L " %[len], %[rseq_scratch2]\n\t"
544			LONG_L " %[dst], %[rseq_scratch1]\n\t"
545			LONG_L " %[src], %[rseq_scratch0]\n\t",
546			cmpfail)
547#ifdef RSEQ_COMPARE_TWICE
548		RSEQ_ASM_DEFINE_CMPFAIL(6,
549			LONG_L " %[len], %[rseq_scratch2]\n\t"
550			LONG_L " %[dst], %[rseq_scratch1]\n\t"
551			LONG_L " %[src], %[rseq_scratch0]\n\t",
552			error1)
553		RSEQ_ASM_DEFINE_CMPFAIL(7,
554			LONG_L " %[len], %[rseq_scratch2]\n\t"
555			LONG_L " %[dst], %[rseq_scratch1]\n\t"
556			LONG_L " %[src], %[rseq_scratch0]\n\t",
557			error2)
558#endif
559		: /* gcc asm goto does not allow outputs */
560		: [cpu_id]		"r" (cpu),
561		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
562		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
563		  /* final store input */
564		  [v]			"m" (*v),
565		  [expect]		"r" (expect),
566		  [newv]		"r" (newv),
567		  /* try memcpy input */
568		  [dst]			"r" (dst),
569		  [src]			"r" (src),
570		  [len]			"r" (len),
571		  [rseq_scratch0]	"m" (rseq_scratch[0]),
572		  [rseq_scratch1]	"m" (rseq_scratch[1]),
573		  [rseq_scratch2]	"m" (rseq_scratch[2])
574		  RSEQ_INJECT_INPUT
575		: "memory", "cc", "r0"
576		  RSEQ_INJECT_CLOBBER
577		: abort, cmpfail
578#ifdef RSEQ_COMPARE_TWICE
579		  , error1, error2
580#endif
581	);
582	rseq_after_asm_goto();
583	return 0;
584abort:
585	rseq_after_asm_goto();
586	RSEQ_INJECT_FAILED
587	return -1;
588cmpfail:
589	rseq_after_asm_goto();
590	return 1;
591#ifdef RSEQ_COMPARE_TWICE
592error1:
593	rseq_after_asm_goto();
594	rseq_bug("cpu_id comparison failed");
595error2:
596	rseq_after_asm_goto();
597	rseq_bug("expected value comparison failed");
598#endif
599}
600
601/* s390 is TSO. */
602static inline __attribute__((always_inline))
603int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect,
604					 void *dst, void *src, size_t len,
605					 intptr_t newv, int cpu)
606{
607	return rseq_cmpeqv_trymemcpy_storev(v, expect, dst, src, len,
608					    newv, cpu);
609}
610#endif /* !RSEQ_SKIP_FASTPATH */
611