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Linux kernel mirror (for testing)
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1/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
2/*
3 * Author: Paul Burton <paul.burton@mips.com>
4 * (C) Copyright 2018 MIPS Tech LLC
5 *
6 * Based on rseq-arm.h:
7 * (C) Copyright 2016-2018 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
8 */
9
10/*
11 * RSEQ_SIG uses the break instruction. The instruction pattern is:
12 *
13 * On MIPS:
14 * 0350000d break 0x350
15 *
16 * On nanoMIPS:
17 * 00100350 break 0x350
18 *
19 * On microMIPS:
20 * 0000d407 break 0x350
21 *
22 * For nanoMIPS32 and microMIPS, the instruction stream is encoded as 16-bit
23 * halfwords, so the signature halfwords need to be swapped accordingly for
24 * little-endian.
25 */
26#if defined(__nanomips__)
27# ifdef __MIPSEL__
28# define RSEQ_SIG 0x03500010
29# else
30# define RSEQ_SIG 0x00100350
31# endif
32#elif defined(__mips_micromips)
33# ifdef __MIPSEL__
34# define RSEQ_SIG 0xd4070000
35# else
36# define RSEQ_SIG 0x0000d407
37# endif
38#elif defined(__mips__)
39# define RSEQ_SIG 0x0350000d
40#else
41/* Unknown MIPS architecture. */
42#endif
43
44#define rseq_smp_mb() __asm__ __volatile__ ("sync" ::: "memory")
45#define rseq_smp_rmb() rseq_smp_mb()
46#define rseq_smp_wmb() rseq_smp_mb()
47
48#define rseq_smp_load_acquire(p) \
49__extension__ ({ \
50 __typeof(*p) ____p1 = RSEQ_READ_ONCE(*p); \
51 rseq_smp_mb(); \
52 ____p1; \
53})
54
55#define rseq_smp_acquire__after_ctrl_dep() rseq_smp_rmb()
56
57#define rseq_smp_store_release(p, v) \
58do { \
59 rseq_smp_mb(); \
60 RSEQ_WRITE_ONCE(*p, v); \
61} while (0)
62
63#ifdef RSEQ_SKIP_FASTPATH
64#include "rseq-skip.h"
65#else /* !RSEQ_SKIP_FASTPATH */
66
67#if _MIPS_SZLONG == 64
68# define LONG ".dword"
69# define LONG_LA "dla"
70# define LONG_L "ld"
71# define LONG_S "sd"
72# define LONG_ADDI "daddiu"
73# define U32_U64_PAD(x) x
74#elif _MIPS_SZLONG == 32
75# define LONG ".word"
76# define LONG_LA "la"
77# define LONG_L "lw"
78# define LONG_S "sw"
79# define LONG_ADDI "addiu"
80# ifdef __BIG_ENDIAN
81# define U32_U64_PAD(x) "0x0, " x
82# else
83# define U32_U64_PAD(x) x ", 0x0"
84# endif
85#else
86# error unsupported _MIPS_SZLONG
87#endif
88
89#define __RSEQ_ASM_DEFINE_TABLE(label, version, flags, start_ip, \
90 post_commit_offset, abort_ip) \
91 ".pushsection __rseq_cs, \"aw\"\n\t" \
92 ".balign 32\n\t" \
93 __rseq_str(label) ":\n\t" \
94 ".word " __rseq_str(version) ", " __rseq_str(flags) "\n\t" \
95 LONG " " U32_U64_PAD(__rseq_str(start_ip)) "\n\t" \
96 LONG " " U32_U64_PAD(__rseq_str(post_commit_offset)) "\n\t" \
97 LONG " " U32_U64_PAD(__rseq_str(abort_ip)) "\n\t" \
98 ".popsection\n\t" \
99 ".pushsection __rseq_cs_ptr_array, \"aw\"\n\t" \
100 LONG " " U32_U64_PAD(__rseq_str(label) "b") "\n\t" \
101 ".popsection\n\t"
102
103#define RSEQ_ASM_DEFINE_TABLE(label, start_ip, post_commit_ip, abort_ip) \
104 __RSEQ_ASM_DEFINE_TABLE(label, 0x0, 0x0, start_ip, \
105 (post_commit_ip - start_ip), abort_ip)
106
107/*
108 * Exit points of a rseq critical section consist of all instructions outside
109 * of the critical section where a critical section can either branch to or
110 * reach through the normal course of its execution. The abort IP and the
111 * post-commit IP are already part of the __rseq_cs section and should not be
112 * explicitly defined as additional exit points. Knowing all exit points is
113 * useful to assist debuggers stepping over the critical section.
114 */
115#define RSEQ_ASM_DEFINE_EXIT_POINT(start_ip, exit_ip) \
116 ".pushsection __rseq_exit_point_array, \"aw\"\n\t" \
117 LONG " " U32_U64_PAD(__rseq_str(start_ip)) "\n\t" \
118 LONG " " U32_U64_PAD(__rseq_str(exit_ip)) "\n\t" \
119 ".popsection\n\t"
120
121#define RSEQ_ASM_STORE_RSEQ_CS(label, cs_label, rseq_cs) \
122 RSEQ_INJECT_ASM(1) \
123 LONG_LA " $4, " __rseq_str(cs_label) "\n\t" \
124 LONG_S " $4, %[" __rseq_str(rseq_cs) "]\n\t" \
125 __rseq_str(label) ":\n\t"
126
127#define RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, label) \
128 RSEQ_INJECT_ASM(2) \
129 "lw $4, %[" __rseq_str(current_cpu_id) "]\n\t" \
130 "bne $4, %[" __rseq_str(cpu_id) "], " __rseq_str(label) "\n\t"
131
132#define __RSEQ_ASM_DEFINE_ABORT(table_label, label, teardown, \
133 abort_label, version, flags, \
134 start_ip, post_commit_offset, abort_ip) \
135 ".balign 32\n\t" \
136 __rseq_str(table_label) ":\n\t" \
137 ".word " __rseq_str(version) ", " __rseq_str(flags) "\n\t" \
138 LONG " " U32_U64_PAD(__rseq_str(start_ip)) "\n\t" \
139 LONG " " U32_U64_PAD(__rseq_str(post_commit_offset)) "\n\t" \
140 LONG " " U32_U64_PAD(__rseq_str(abort_ip)) "\n\t" \
141 ".word " __rseq_str(RSEQ_SIG) "\n\t" \
142 __rseq_str(label) ":\n\t" \
143 teardown \
144 "b %l[" __rseq_str(abort_label) "]\n\t"
145
146#define RSEQ_ASM_DEFINE_ABORT(table_label, label, teardown, abort_label, \
147 start_ip, post_commit_ip, abort_ip) \
148 __RSEQ_ASM_DEFINE_ABORT(table_label, label, teardown, \
149 abort_label, 0x0, 0x0, start_ip, \
150 (post_commit_ip - start_ip), abort_ip)
151
152#define RSEQ_ASM_DEFINE_CMPFAIL(label, teardown, cmpfail_label) \
153 __rseq_str(label) ":\n\t" \
154 teardown \
155 "b %l[" __rseq_str(cmpfail_label) "]\n\t"
156
157#define rseq_workaround_gcc_asm_size_guess() __asm__ __volatile__("")
158
159static inline __attribute__((always_inline))
160int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
161{
162 RSEQ_INJECT_C(9)
163
164 rseq_workaround_gcc_asm_size_guess();
165 __asm__ __volatile__ goto (
166 RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
167 RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
168#ifdef RSEQ_COMPARE_TWICE
169 RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
170 RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2])
171#endif
172 /* Start rseq by storing table entry pointer into rseq_cs. */
173 RSEQ_ASM_STORE_RSEQ_CS(1, 3f, rseq_cs)
174 RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
175 RSEQ_INJECT_ASM(3)
176 LONG_L " $4, %[v]\n\t"
177 "bne $4, %[expect], %l[cmpfail]\n\t"
178 RSEQ_INJECT_ASM(4)
179#ifdef RSEQ_COMPARE_TWICE
180 RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1])
181 LONG_L " $4, %[v]\n\t"
182 "bne $4, %[expect], %l[error2]\n\t"
183#endif
184 /* final store */
185 LONG_S " %[newv], %[v]\n\t"
186 "2:\n\t"
187 RSEQ_INJECT_ASM(5)
188 "b 5f\n\t"
189 RSEQ_ASM_DEFINE_ABORT(3, 4, "", abort, 1b, 2b, 4f)
190 "5:\n\t"
191 : /* gcc asm goto does not allow outputs */
192 : [cpu_id] "r" (cpu),
193 [current_cpu_id] "m" (__rseq_abi.cpu_id),
194 [rseq_cs] "m" (__rseq_abi.rseq_cs),
195 [v] "m" (*v),
196 [expect] "r" (expect),
197 [newv] "r" (newv)
198 RSEQ_INJECT_INPUT
199 : "$4", "memory"
200 RSEQ_INJECT_CLOBBER
201 : abort, cmpfail
202#ifdef RSEQ_COMPARE_TWICE
203 , error1, error2
204#endif
205 );
206 rseq_workaround_gcc_asm_size_guess();
207 return 0;
208abort:
209 rseq_workaround_gcc_asm_size_guess();
210 RSEQ_INJECT_FAILED
211 return -1;
212cmpfail:
213 rseq_workaround_gcc_asm_size_guess();
214 return 1;
215#ifdef RSEQ_COMPARE_TWICE
216error1:
217 rseq_bug("cpu_id comparison failed");
218error2:
219 rseq_bug("expected value comparison failed");
220#endif
221}
222
223static inline __attribute__((always_inline))
224int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
225 off_t voffp, intptr_t *load, int cpu)
226{
227 RSEQ_INJECT_C(9)
228
229 rseq_workaround_gcc_asm_size_guess();
230 __asm__ __volatile__ goto (
231 RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
232 RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
233#ifdef RSEQ_COMPARE_TWICE
234 RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
235 RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2])
236#endif
237 /* Start rseq by storing table entry pointer into rseq_cs. */
238 RSEQ_ASM_STORE_RSEQ_CS(1, 3f, rseq_cs)
239 RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
240 RSEQ_INJECT_ASM(3)
241 LONG_L " $4, %[v]\n\t"
242 "beq $4, %[expectnot], %l[cmpfail]\n\t"
243 RSEQ_INJECT_ASM(4)
244#ifdef RSEQ_COMPARE_TWICE
245 RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1])
246 LONG_L " $4, %[v]\n\t"
247 "beq $4, %[expectnot], %l[error2]\n\t"
248#endif
249 LONG_S " $4, %[load]\n\t"
250 LONG_ADDI " $4, %[voffp]\n\t"
251 LONG_L " $4, 0($4)\n\t"
252 /* final store */
253 LONG_S " $4, %[v]\n\t"
254 "2:\n\t"
255 RSEQ_INJECT_ASM(5)
256 "b 5f\n\t"
257 RSEQ_ASM_DEFINE_ABORT(3, 4, "", abort, 1b, 2b, 4f)
258 "5:\n\t"
259 : /* gcc asm goto does not allow outputs */
260 : [cpu_id] "r" (cpu),
261 [current_cpu_id] "m" (__rseq_abi.cpu_id),
262 [rseq_cs] "m" (__rseq_abi.rseq_cs),
263 /* final store input */
264 [v] "m" (*v),
265 [expectnot] "r" (expectnot),
266 [voffp] "Ir" (voffp),
267 [load] "m" (*load)
268 RSEQ_INJECT_INPUT
269 : "$4", "memory"
270 RSEQ_INJECT_CLOBBER
271 : abort, cmpfail
272#ifdef RSEQ_COMPARE_TWICE
273 , error1, error2
274#endif
275 );
276 rseq_workaround_gcc_asm_size_guess();
277 return 0;
278abort:
279 rseq_workaround_gcc_asm_size_guess();
280 RSEQ_INJECT_FAILED
281 return -1;
282cmpfail:
283 rseq_workaround_gcc_asm_size_guess();
284 return 1;
285#ifdef RSEQ_COMPARE_TWICE
286error1:
287 rseq_bug("cpu_id comparison failed");
288error2:
289 rseq_bug("expected value comparison failed");
290#endif
291}
292
293static inline __attribute__((always_inline))
294int rseq_addv(intptr_t *v, intptr_t count, int cpu)
295{
296 RSEQ_INJECT_C(9)
297
298 rseq_workaround_gcc_asm_size_guess();
299 __asm__ __volatile__ goto (
300 RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
301#ifdef RSEQ_COMPARE_TWICE
302 RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
303#endif
304 /* Start rseq by storing table entry pointer into rseq_cs. */
305 RSEQ_ASM_STORE_RSEQ_CS(1, 3f, rseq_cs)
306 RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
307 RSEQ_INJECT_ASM(3)
308#ifdef RSEQ_COMPARE_TWICE
309 RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1])
310#endif
311 LONG_L " $4, %[v]\n\t"
312 LONG_ADDI " $4, %[count]\n\t"
313 /* final store */
314 LONG_S " $4, %[v]\n\t"
315 "2:\n\t"
316 RSEQ_INJECT_ASM(4)
317 "b 5f\n\t"
318 RSEQ_ASM_DEFINE_ABORT(3, 4, "", abort, 1b, 2b, 4f)
319 "5:\n\t"
320 : /* gcc asm goto does not allow outputs */
321 : [cpu_id] "r" (cpu),
322 [current_cpu_id] "m" (__rseq_abi.cpu_id),
323 [rseq_cs] "m" (__rseq_abi.rseq_cs),
324 [v] "m" (*v),
325 [count] "Ir" (count)
326 RSEQ_INJECT_INPUT
327 : "$4", "memory"
328 RSEQ_INJECT_CLOBBER
329 : abort
330#ifdef RSEQ_COMPARE_TWICE
331 , error1
332#endif
333 );
334 rseq_workaround_gcc_asm_size_guess();
335 return 0;
336abort:
337 rseq_workaround_gcc_asm_size_guess();
338 RSEQ_INJECT_FAILED
339 return -1;
340#ifdef RSEQ_COMPARE_TWICE
341error1:
342 rseq_bug("cpu_id comparison failed");
343#endif
344}
345
346static inline __attribute__((always_inline))
347int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
348 intptr_t *v2, intptr_t newv2,
349 intptr_t newv, int cpu)
350{
351 RSEQ_INJECT_C(9)
352
353 rseq_workaround_gcc_asm_size_guess();
354 __asm__ __volatile__ goto (
355 RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
356 RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
357#ifdef RSEQ_COMPARE_TWICE
358 RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
359 RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2])
360#endif
361 /* Start rseq by storing table entry pointer into rseq_cs. */
362 RSEQ_ASM_STORE_RSEQ_CS(1, 3f, rseq_cs)
363 RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
364 RSEQ_INJECT_ASM(3)
365 LONG_L " $4, %[v]\n\t"
366 "bne $4, %[expect], %l[cmpfail]\n\t"
367 RSEQ_INJECT_ASM(4)
368#ifdef RSEQ_COMPARE_TWICE
369 RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1])
370 LONG_L " $4, %[v]\n\t"
371 "bne $4, %[expect], %l[error2]\n\t"
372#endif
373 /* try store */
374 LONG_S " %[newv2], %[v2]\n\t"
375 RSEQ_INJECT_ASM(5)
376 /* final store */
377 LONG_S " %[newv], %[v]\n\t"
378 "2:\n\t"
379 RSEQ_INJECT_ASM(6)
380 "b 5f\n\t"
381 RSEQ_ASM_DEFINE_ABORT(3, 4, "", abort, 1b, 2b, 4f)
382 "5:\n\t"
383 : /* gcc asm goto does not allow outputs */
384 : [cpu_id] "r" (cpu),
385 [current_cpu_id] "m" (__rseq_abi.cpu_id),
386 [rseq_cs] "m" (__rseq_abi.rseq_cs),
387 /* try store input */
388 [v2] "m" (*v2),
389 [newv2] "r" (newv2),
390 /* final store input */
391 [v] "m" (*v),
392 [expect] "r" (expect),
393 [newv] "r" (newv)
394 RSEQ_INJECT_INPUT
395 : "$4", "memory"
396 RSEQ_INJECT_CLOBBER
397 : abort, cmpfail
398#ifdef RSEQ_COMPARE_TWICE
399 , error1, error2
400#endif
401 );
402 rseq_workaround_gcc_asm_size_guess();
403 return 0;
404abort:
405 rseq_workaround_gcc_asm_size_guess();
406 RSEQ_INJECT_FAILED
407 return -1;
408cmpfail:
409 rseq_workaround_gcc_asm_size_guess();
410 return 1;
411#ifdef RSEQ_COMPARE_TWICE
412error1:
413 rseq_bug("cpu_id comparison failed");
414error2:
415 rseq_bug("expected value comparison failed");
416#endif
417}
418
419static inline __attribute__((always_inline))
420int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect,
421 intptr_t *v2, intptr_t newv2,
422 intptr_t newv, int cpu)
423{
424 RSEQ_INJECT_C(9)
425
426 rseq_workaround_gcc_asm_size_guess();
427 __asm__ __volatile__ goto (
428 RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
429 RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
430#ifdef RSEQ_COMPARE_TWICE
431 RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
432 RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2])
433#endif
434 /* Start rseq by storing table entry pointer into rseq_cs. */
435 RSEQ_ASM_STORE_RSEQ_CS(1, 3f, rseq_cs)
436 RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
437 RSEQ_INJECT_ASM(3)
438 LONG_L " $4, %[v]\n\t"
439 "bne $4, %[expect], %l[cmpfail]\n\t"
440 RSEQ_INJECT_ASM(4)
441#ifdef RSEQ_COMPARE_TWICE
442 RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1])
443 LONG_L " $4, %[v]\n\t"
444 "bne $4, %[expect], %l[error2]\n\t"
445#endif
446 /* try store */
447 LONG_S " %[newv2], %[v2]\n\t"
448 RSEQ_INJECT_ASM(5)
449 "sync\n\t" /* full sync provides store-release */
450 /* final store */
451 LONG_S " %[newv], %[v]\n\t"
452 "2:\n\t"
453 RSEQ_INJECT_ASM(6)
454 "b 5f\n\t"
455 RSEQ_ASM_DEFINE_ABORT(3, 4, "", abort, 1b, 2b, 4f)
456 "5:\n\t"
457 : /* gcc asm goto does not allow outputs */
458 : [cpu_id] "r" (cpu),
459 [current_cpu_id] "m" (__rseq_abi.cpu_id),
460 [rseq_cs] "m" (__rseq_abi.rseq_cs),
461 /* try store input */
462 [v2] "m" (*v2),
463 [newv2] "r" (newv2),
464 /* final store input */
465 [v] "m" (*v),
466 [expect] "r" (expect),
467 [newv] "r" (newv)
468 RSEQ_INJECT_INPUT
469 : "$4", "memory"
470 RSEQ_INJECT_CLOBBER
471 : abort, cmpfail
472#ifdef RSEQ_COMPARE_TWICE
473 , error1, error2
474#endif
475 );
476 rseq_workaround_gcc_asm_size_guess();
477 return 0;
478abort:
479 rseq_workaround_gcc_asm_size_guess();
480 RSEQ_INJECT_FAILED
481 return -1;
482cmpfail:
483 rseq_workaround_gcc_asm_size_guess();
484 return 1;
485#ifdef RSEQ_COMPARE_TWICE
486error1:
487 rseq_bug("cpu_id comparison failed");
488error2:
489 rseq_bug("expected value comparison failed");
490#endif
491}
492
493static inline __attribute__((always_inline))
494int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
495 intptr_t *v2, intptr_t expect2,
496 intptr_t newv, int cpu)
497{
498 RSEQ_INJECT_C(9)
499
500 rseq_workaround_gcc_asm_size_guess();
501 __asm__ __volatile__ goto (
502 RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
503 RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
504#ifdef RSEQ_COMPARE_TWICE
505 RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
506 RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2])
507 RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error3])
508#endif
509 /* Start rseq by storing table entry pointer into rseq_cs. */
510 RSEQ_ASM_STORE_RSEQ_CS(1, 3f, rseq_cs)
511 RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
512 RSEQ_INJECT_ASM(3)
513 LONG_L " $4, %[v]\n\t"
514 "bne $4, %[expect], %l[cmpfail]\n\t"
515 RSEQ_INJECT_ASM(4)
516 LONG_L " $4, %[v2]\n\t"
517 "bne $4, %[expect2], %l[cmpfail]\n\t"
518 RSEQ_INJECT_ASM(5)
519#ifdef RSEQ_COMPARE_TWICE
520 RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1])
521 LONG_L " $4, %[v]\n\t"
522 "bne $4, %[expect], %l[error2]\n\t"
523 LONG_L " $4, %[v2]\n\t"
524 "bne $4, %[expect2], %l[error3]\n\t"
525#endif
526 /* final store */
527 LONG_S " %[newv], %[v]\n\t"
528 "2:\n\t"
529 RSEQ_INJECT_ASM(6)
530 "b 5f\n\t"
531 RSEQ_ASM_DEFINE_ABORT(3, 4, "", abort, 1b, 2b, 4f)
532 "5:\n\t"
533 : /* gcc asm goto does not allow outputs */
534 : [cpu_id] "r" (cpu),
535 [current_cpu_id] "m" (__rseq_abi.cpu_id),
536 [rseq_cs] "m" (__rseq_abi.rseq_cs),
537 /* cmp2 input */
538 [v2] "m" (*v2),
539 [expect2] "r" (expect2),
540 /* final store input */
541 [v] "m" (*v),
542 [expect] "r" (expect),
543 [newv] "r" (newv)
544 RSEQ_INJECT_INPUT
545 : "$4", "memory"
546 RSEQ_INJECT_CLOBBER
547 : abort, cmpfail
548#ifdef RSEQ_COMPARE_TWICE
549 , error1, error2, error3
550#endif
551 );
552 rseq_workaround_gcc_asm_size_guess();
553 return 0;
554abort:
555 rseq_workaround_gcc_asm_size_guess();
556 RSEQ_INJECT_FAILED
557 return -1;
558cmpfail:
559 rseq_workaround_gcc_asm_size_guess();
560 return 1;
561#ifdef RSEQ_COMPARE_TWICE
562error1:
563 rseq_bug("cpu_id comparison failed");
564error2:
565 rseq_bug("1st expected value comparison failed");
566error3:
567 rseq_bug("2nd expected value comparison failed");
568#endif
569}
570
571static inline __attribute__((always_inline))
572int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
573 void *dst, void *src, size_t len,
574 intptr_t newv, int cpu)
575{
576 uintptr_t rseq_scratch[3];
577
578 RSEQ_INJECT_C(9)
579
580 rseq_workaround_gcc_asm_size_guess();
581 __asm__ __volatile__ goto (
582 RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
583 RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
584#ifdef RSEQ_COMPARE_TWICE
585 RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
586 RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2])
587#endif
588 LONG_S " %[src], %[rseq_scratch0]\n\t"
589 LONG_S " %[dst], %[rseq_scratch1]\n\t"
590 LONG_S " %[len], %[rseq_scratch2]\n\t"
591 /* Start rseq by storing table entry pointer into rseq_cs. */
592 RSEQ_ASM_STORE_RSEQ_CS(1, 3f, rseq_cs)
593 RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
594 RSEQ_INJECT_ASM(3)
595 LONG_L " $4, %[v]\n\t"
596 "bne $4, %[expect], 5f\n\t"
597 RSEQ_INJECT_ASM(4)
598#ifdef RSEQ_COMPARE_TWICE
599 RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 6f)
600 LONG_L " $4, %[v]\n\t"
601 "bne $4, %[expect], 7f\n\t"
602#endif
603 /* try memcpy */
604 "beqz %[len], 333f\n\t" \
605 "222:\n\t" \
606 "lb $4, 0(%[src])\n\t" \
607 "sb $4, 0(%[dst])\n\t" \
608 LONG_ADDI " %[src], 1\n\t" \
609 LONG_ADDI " %[dst], 1\n\t" \
610 LONG_ADDI " %[len], -1\n\t" \
611 "bnez %[len], 222b\n\t" \
612 "333:\n\t" \
613 RSEQ_INJECT_ASM(5)
614 /* final store */
615 LONG_S " %[newv], %[v]\n\t"
616 "2:\n\t"
617 RSEQ_INJECT_ASM(6)
618 /* teardown */
619 LONG_L " %[len], %[rseq_scratch2]\n\t"
620 LONG_L " %[dst], %[rseq_scratch1]\n\t"
621 LONG_L " %[src], %[rseq_scratch0]\n\t"
622 "b 8f\n\t"
623 RSEQ_ASM_DEFINE_ABORT(3, 4,
624 /* teardown */
625 LONG_L " %[len], %[rseq_scratch2]\n\t"
626 LONG_L " %[dst], %[rseq_scratch1]\n\t"
627 LONG_L " %[src], %[rseq_scratch0]\n\t",
628 abort, 1b, 2b, 4f)
629 RSEQ_ASM_DEFINE_CMPFAIL(5,
630 /* teardown */
631 LONG_L " %[len], %[rseq_scratch2]\n\t"
632 LONG_L " %[dst], %[rseq_scratch1]\n\t"
633 LONG_L " %[src], %[rseq_scratch0]\n\t",
634 cmpfail)
635#ifdef RSEQ_COMPARE_TWICE
636 RSEQ_ASM_DEFINE_CMPFAIL(6,
637 /* teardown */
638 LONG_L " %[len], %[rseq_scratch2]\n\t"
639 LONG_L " %[dst], %[rseq_scratch1]\n\t"
640 LONG_L " %[src], %[rseq_scratch0]\n\t",
641 error1)
642 RSEQ_ASM_DEFINE_CMPFAIL(7,
643 /* teardown */
644 LONG_L " %[len], %[rseq_scratch2]\n\t"
645 LONG_L " %[dst], %[rseq_scratch1]\n\t"
646 LONG_L " %[src], %[rseq_scratch0]\n\t",
647 error2)
648#endif
649 "8:\n\t"
650 : /* gcc asm goto does not allow outputs */
651 : [cpu_id] "r" (cpu),
652 [current_cpu_id] "m" (__rseq_abi.cpu_id),
653 [rseq_cs] "m" (__rseq_abi.rseq_cs),
654 /* final store input */
655 [v] "m" (*v),
656 [expect] "r" (expect),
657 [newv] "r" (newv),
658 /* try memcpy input */
659 [dst] "r" (dst),
660 [src] "r" (src),
661 [len] "r" (len),
662 [rseq_scratch0] "m" (rseq_scratch[0]),
663 [rseq_scratch1] "m" (rseq_scratch[1]),
664 [rseq_scratch2] "m" (rseq_scratch[2])
665 RSEQ_INJECT_INPUT
666 : "$4", "memory"
667 RSEQ_INJECT_CLOBBER
668 : abort, cmpfail
669#ifdef RSEQ_COMPARE_TWICE
670 , error1, error2
671#endif
672 );
673 rseq_workaround_gcc_asm_size_guess();
674 return 0;
675abort:
676 rseq_workaround_gcc_asm_size_guess();
677 RSEQ_INJECT_FAILED
678 return -1;
679cmpfail:
680 rseq_workaround_gcc_asm_size_guess();
681 return 1;
682#ifdef RSEQ_COMPARE_TWICE
683error1:
684 rseq_workaround_gcc_asm_size_guess();
685 rseq_bug("cpu_id comparison failed");
686error2:
687 rseq_workaround_gcc_asm_size_guess();
688 rseq_bug("expected value comparison failed");
689#endif
690}
691
692static inline __attribute__((always_inline))
693int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect,
694 void *dst, void *src, size_t len,
695 intptr_t newv, int cpu)
696{
697 uintptr_t rseq_scratch[3];
698
699 RSEQ_INJECT_C(9)
700
701 rseq_workaround_gcc_asm_size_guess();
702 __asm__ __volatile__ goto (
703 RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
704 RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
705#ifdef RSEQ_COMPARE_TWICE
706 RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
707 RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2])
708#endif
709 LONG_S " %[src], %[rseq_scratch0]\n\t"
710 LONG_S " %[dst], %[rseq_scratch1]\n\t"
711 LONG_S " %[len], %[rseq_scratch2]\n\t"
712 /* Start rseq by storing table entry pointer into rseq_cs. */
713 RSEQ_ASM_STORE_RSEQ_CS(1, 3f, rseq_cs)
714 RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f)
715 RSEQ_INJECT_ASM(3)
716 LONG_L " $4, %[v]\n\t"
717 "bne $4, %[expect], 5f\n\t"
718 RSEQ_INJECT_ASM(4)
719#ifdef RSEQ_COMPARE_TWICE
720 RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 6f)
721 LONG_L " $4, %[v]\n\t"
722 "bne $4, %[expect], 7f\n\t"
723#endif
724 /* try memcpy */
725 "beqz %[len], 333f\n\t" \
726 "222:\n\t" \
727 "lb $4, 0(%[src])\n\t" \
728 "sb $4, 0(%[dst])\n\t" \
729 LONG_ADDI " %[src], 1\n\t" \
730 LONG_ADDI " %[dst], 1\n\t" \
731 LONG_ADDI " %[len], -1\n\t" \
732 "bnez %[len], 222b\n\t" \
733 "333:\n\t" \
734 RSEQ_INJECT_ASM(5)
735 "sync\n\t" /* full sync provides store-release */
736 /* final store */
737 LONG_S " %[newv], %[v]\n\t"
738 "2:\n\t"
739 RSEQ_INJECT_ASM(6)
740 /* teardown */
741 LONG_L " %[len], %[rseq_scratch2]\n\t"
742 LONG_L " %[dst], %[rseq_scratch1]\n\t"
743 LONG_L " %[src], %[rseq_scratch0]\n\t"
744 "b 8f\n\t"
745 RSEQ_ASM_DEFINE_ABORT(3, 4,
746 /* teardown */
747 LONG_L " %[len], %[rseq_scratch2]\n\t"
748 LONG_L " %[dst], %[rseq_scratch1]\n\t"
749 LONG_L " %[src], %[rseq_scratch0]\n\t",
750 abort, 1b, 2b, 4f)
751 RSEQ_ASM_DEFINE_CMPFAIL(5,
752 /* teardown */
753 LONG_L " %[len], %[rseq_scratch2]\n\t"
754 LONG_L " %[dst], %[rseq_scratch1]\n\t"
755 LONG_L " %[src], %[rseq_scratch0]\n\t",
756 cmpfail)
757#ifdef RSEQ_COMPARE_TWICE
758 RSEQ_ASM_DEFINE_CMPFAIL(6,
759 /* teardown */
760 LONG_L " %[len], %[rseq_scratch2]\n\t"
761 LONG_L " %[dst], %[rseq_scratch1]\n\t"
762 LONG_L " %[src], %[rseq_scratch0]\n\t",
763 error1)
764 RSEQ_ASM_DEFINE_CMPFAIL(7,
765 /* teardown */
766 LONG_L " %[len], %[rseq_scratch2]\n\t"
767 LONG_L " %[dst], %[rseq_scratch1]\n\t"
768 LONG_L " %[src], %[rseq_scratch0]\n\t",
769 error2)
770#endif
771 "8:\n\t"
772 : /* gcc asm goto does not allow outputs */
773 : [cpu_id] "r" (cpu),
774 [current_cpu_id] "m" (__rseq_abi.cpu_id),
775 [rseq_cs] "m" (__rseq_abi.rseq_cs),
776 /* final store input */
777 [v] "m" (*v),
778 [expect] "r" (expect),
779 [newv] "r" (newv),
780 /* try memcpy input */
781 [dst] "r" (dst),
782 [src] "r" (src),
783 [len] "r" (len),
784 [rseq_scratch0] "m" (rseq_scratch[0]),
785 [rseq_scratch1] "m" (rseq_scratch[1]),
786 [rseq_scratch2] "m" (rseq_scratch[2])
787 RSEQ_INJECT_INPUT
788 : "$4", "memory"
789 RSEQ_INJECT_CLOBBER
790 : abort, cmpfail
791#ifdef RSEQ_COMPARE_TWICE
792 , error1, error2
793#endif
794 );
795 rseq_workaround_gcc_asm_size_guess();
796 return 0;
797abort:
798 rseq_workaround_gcc_asm_size_guess();
799 RSEQ_INJECT_FAILED
800 return -1;
801cmpfail:
802 rseq_workaround_gcc_asm_size_guess();
803 return 1;
804#ifdef RSEQ_COMPARE_TWICE
805error1:
806 rseq_workaround_gcc_asm_size_guess();
807 rseq_bug("cpu_id comparison failed");
808error2:
809 rseq_workaround_gcc_asm_size_guess();
810 rseq_bug("expected value comparison failed");
811#endif
812}
813
814#endif /* !RSEQ_SKIP_FASTPATH */