xref: /openbmc/qemu/accel/tcg/user-exec.c (revision 0b84b662)
1 /*
2  *  User emulator execution
3  *
4  *  Copyright (c) 2003-2005 Fabrice Bellard
5  *
6  * This library is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * This library is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
18  */
19 #include "qemu/osdep.h"
20 #include "cpu.h"
21 #include "disas/disas.h"
22 #include "exec/exec-all.h"
23 #include "tcg.h"
24 #include "qemu/bitops.h"
25 #include "exec/cpu_ldst.h"
26 #include "translate-all.h"
27 #include "exec/helper-proto.h"
28 #include "qemu/atomic128.h"
29 
30 #undef EAX
31 #undef ECX
32 #undef EDX
33 #undef EBX
34 #undef ESP
35 #undef EBP
36 #undef ESI
37 #undef EDI
38 #undef EIP
39 #ifdef __linux__
40 #include <sys/ucontext.h>
41 #endif
42 
43 __thread uintptr_t helper_retaddr;
44 
45 //#define DEBUG_SIGNAL
46 
47 /* exit the current TB from a signal handler. The host registers are
48    restored in a state compatible with the CPU emulator
49  */
50 static void cpu_exit_tb_from_sighandler(CPUState *cpu, sigset_t *old_set)
51 {
52     /* XXX: use siglongjmp ? */
53     sigprocmask(SIG_SETMASK, old_set, NULL);
54     cpu_loop_exit_noexc(cpu);
55 }
56 
57 /* 'pc' is the host PC at which the exception was raised. 'address' is
58    the effective address of the memory exception. 'is_write' is 1 if a
59    write caused the exception and otherwise 0'. 'old_set' is the
60    signal set which should be restored */
61 static inline int handle_cpu_signal(uintptr_t pc, siginfo_t *info,
62                                     int is_write, sigset_t *old_set)
63 {
64     CPUState *cpu = current_cpu;
65     CPUClass *cc;
66     unsigned long address = (unsigned long)info->si_addr;
67     MMUAccessType access_type = is_write ? MMU_DATA_STORE : MMU_DATA_LOAD;
68 
69     switch (helper_retaddr) {
70     default:
71         /*
72          * Fault during host memory operation within a helper function.
73          * The helper's host return address, saved here, gives us a
74          * pointer into the generated code that will unwind to the
75          * correct guest pc.
76          */
77         pc = helper_retaddr;
78         break;
79 
80     case 0:
81         /*
82          * Fault during host memory operation within generated code.
83          * (Or, a unrelated bug within qemu, but we can't tell from here).
84          *
85          * We take the host pc from the signal frame.  However, we cannot
86          * use that value directly.  Within cpu_restore_state_from_tb, we
87          * assume PC comes from GETPC(), as used by the helper functions,
88          * so we adjust the address by -GETPC_ADJ to form an address that
89          * is within the call insn, so that the address does not accidentially
90          * match the beginning of the next guest insn.  However, when the
91          * pc comes from the signal frame it points to the actual faulting
92          * host memory insn and not the return from a call insn.
93          *
94          * Therefore, adjust to compensate for what will be done later
95          * by cpu_restore_state_from_tb.
96          */
97         pc += GETPC_ADJ;
98         break;
99 
100     case 1:
101         /*
102          * Fault during host read for translation, or loosely, "execution".
103          *
104          * The guest pc is already pointing to the start of the TB for which
105          * code is being generated.  If the guest translator manages the
106          * page crossings correctly, this is exactly the correct address
107          * (and if the translator doesn't handle page boundaries correctly
108          * there's little we can do about that here).  Therefore, do not
109          * trigger the unwinder.
110          *
111          * Like tb_gen_code, release the memory lock before cpu_loop_exit.
112          */
113         pc = 0;
114         access_type = MMU_INST_FETCH;
115         mmap_unlock();
116         break;
117     }
118 
119     /* For synchronous signals we expect to be coming from the vCPU
120      * thread (so current_cpu should be valid) and either from running
121      * code or during translation which can fault as we cross pages.
122      *
123      * If neither is true then something has gone wrong and we should
124      * abort rather than try and restart the vCPU execution.
125      */
126     if (!cpu || !cpu->running) {
127         printf("qemu:%s received signal outside vCPU context @ pc=0x%"
128                PRIxPTR "\n",  __func__, pc);
129         abort();
130     }
131 
132 #if defined(DEBUG_SIGNAL)
133     printf("qemu: SIGSEGV pc=0x%08lx address=%08lx w=%d oldset=0x%08lx\n",
134            pc, address, is_write, *(unsigned long *)old_set);
135 #endif
136     /* XXX: locking issue */
137     /* Note that it is important that we don't call page_unprotect() unless
138      * this is really a "write to nonwriteable page" fault, because
139      * page_unprotect() assumes that if it is called for an access to
140      * a page that's writeable this means we had two threads racing and
141      * another thread got there first and already made the page writeable;
142      * so we will retry the access. If we were to call page_unprotect()
143      * for some other kind of fault that should really be passed to the
144      * guest, we'd end up in an infinite loop of retrying the faulting
145      * access.
146      */
147     if (is_write && info->si_signo == SIGSEGV && info->si_code == SEGV_ACCERR &&
148         h2g_valid(address)) {
149         switch (page_unprotect(h2g(address), pc)) {
150         case 0:
151             /* Fault not caused by a page marked unwritable to protect
152              * cached translations, must be the guest binary's problem.
153              */
154             break;
155         case 1:
156             /* Fault caused by protection of cached translation; TBs
157              * invalidated, so resume execution.  Retain helper_retaddr
158              * for a possible second fault.
159              */
160             return 1;
161         case 2:
162             /* Fault caused by protection of cached translation, and the
163              * currently executing TB was modified and must be exited
164              * immediately.  Clear helper_retaddr for next execution.
165              */
166             clear_helper_retaddr();
167             cpu_exit_tb_from_sighandler(cpu, old_set);
168             /* NORETURN */
169 
170         default:
171             g_assert_not_reached();
172         }
173     }
174 
175     /* Convert forcefully to guest address space, invalid addresses
176        are still valid segv ones */
177     address = h2g_nocheck(address);
178 
179     /*
180      * There is no way the target can handle this other than raising
181      * an exception.  Undo signal and retaddr state prior to longjmp.
182      */
183     sigprocmask(SIG_SETMASK, old_set, NULL);
184     clear_helper_retaddr();
185 
186     cc = CPU_GET_CLASS(cpu);
187     cc->tlb_fill(cpu, address, 0, access_type, MMU_USER_IDX, false, pc);
188     g_assert_not_reached();
189 }
190 
191 void *probe_access(CPUArchState *env, target_ulong addr, int size,
192                    MMUAccessType access_type, int mmu_idx, uintptr_t retaddr)
193 {
194     int flags;
195 
196     g_assert(-(addr | TARGET_PAGE_MASK) >= size);
197 
198     switch (access_type) {
199     case MMU_DATA_STORE:
200         flags = PAGE_WRITE;
201         break;
202     case MMU_DATA_LOAD:
203         flags = PAGE_READ;
204         break;
205     case MMU_INST_FETCH:
206         flags = PAGE_EXEC;
207         break;
208     default:
209         g_assert_not_reached();
210     }
211 
212     if (!guest_addr_valid(addr) || page_check_range(addr, size, flags) < 0) {
213         CPUState *cpu = env_cpu(env);
214         CPUClass *cc = CPU_GET_CLASS(cpu);
215         cc->tlb_fill(cpu, addr, size, access_type, MMU_USER_IDX, false,
216                      retaddr);
217         g_assert_not_reached();
218     }
219 
220     return size ? g2h(addr) : NULL;
221 }
222 
223 #if defined(__i386__)
224 
225 #if defined(__NetBSD__)
226 #include <ucontext.h>
227 
228 #define EIP_sig(context)     ((context)->uc_mcontext.__gregs[_REG_EIP])
229 #define TRAP_sig(context)    ((context)->uc_mcontext.__gregs[_REG_TRAPNO])
230 #define ERROR_sig(context)   ((context)->uc_mcontext.__gregs[_REG_ERR])
231 #define MASK_sig(context)    ((context)->uc_sigmask)
232 #elif defined(__FreeBSD__) || defined(__DragonFly__)
233 #include <ucontext.h>
234 
235 #define EIP_sig(context)  (*((unsigned long *)&(context)->uc_mcontext.mc_eip))
236 #define TRAP_sig(context)    ((context)->uc_mcontext.mc_trapno)
237 #define ERROR_sig(context)   ((context)->uc_mcontext.mc_err)
238 #define MASK_sig(context)    ((context)->uc_sigmask)
239 #elif defined(__OpenBSD__)
240 #define EIP_sig(context)     ((context)->sc_eip)
241 #define TRAP_sig(context)    ((context)->sc_trapno)
242 #define ERROR_sig(context)   ((context)->sc_err)
243 #define MASK_sig(context)    ((context)->sc_mask)
244 #else
245 #define EIP_sig(context)     ((context)->uc_mcontext.gregs[REG_EIP])
246 #define TRAP_sig(context)    ((context)->uc_mcontext.gregs[REG_TRAPNO])
247 #define ERROR_sig(context)   ((context)->uc_mcontext.gregs[REG_ERR])
248 #define MASK_sig(context)    ((context)->uc_sigmask)
249 #endif
250 
251 int cpu_signal_handler(int host_signum, void *pinfo,
252                        void *puc)
253 {
254     siginfo_t *info = pinfo;
255 #if defined(__NetBSD__) || defined(__FreeBSD__) || defined(__DragonFly__)
256     ucontext_t *uc = puc;
257 #elif defined(__OpenBSD__)
258     struct sigcontext *uc = puc;
259 #else
260     ucontext_t *uc = puc;
261 #endif
262     unsigned long pc;
263     int trapno;
264 
265 #ifndef REG_EIP
266 /* for glibc 2.1 */
267 #define REG_EIP    EIP
268 #define REG_ERR    ERR
269 #define REG_TRAPNO TRAPNO
270 #endif
271     pc = EIP_sig(uc);
272     trapno = TRAP_sig(uc);
273     return handle_cpu_signal(pc, info,
274                              trapno == 0xe ? (ERROR_sig(uc) >> 1) & 1 : 0,
275                              &MASK_sig(uc));
276 }
277 
278 #elif defined(__x86_64__)
279 
280 #ifdef __NetBSD__
281 #define PC_sig(context)       _UC_MACHINE_PC(context)
282 #define TRAP_sig(context)     ((context)->uc_mcontext.__gregs[_REG_TRAPNO])
283 #define ERROR_sig(context)    ((context)->uc_mcontext.__gregs[_REG_ERR])
284 #define MASK_sig(context)     ((context)->uc_sigmask)
285 #elif defined(__OpenBSD__)
286 #define PC_sig(context)       ((context)->sc_rip)
287 #define TRAP_sig(context)     ((context)->sc_trapno)
288 #define ERROR_sig(context)    ((context)->sc_err)
289 #define MASK_sig(context)     ((context)->sc_mask)
290 #elif defined(__FreeBSD__) || defined(__DragonFly__)
291 #include <ucontext.h>
292 
293 #define PC_sig(context)  (*((unsigned long *)&(context)->uc_mcontext.mc_rip))
294 #define TRAP_sig(context)     ((context)->uc_mcontext.mc_trapno)
295 #define ERROR_sig(context)    ((context)->uc_mcontext.mc_err)
296 #define MASK_sig(context)     ((context)->uc_sigmask)
297 #else
298 #define PC_sig(context)       ((context)->uc_mcontext.gregs[REG_RIP])
299 #define TRAP_sig(context)     ((context)->uc_mcontext.gregs[REG_TRAPNO])
300 #define ERROR_sig(context)    ((context)->uc_mcontext.gregs[REG_ERR])
301 #define MASK_sig(context)     ((context)->uc_sigmask)
302 #endif
303 
304 int cpu_signal_handler(int host_signum, void *pinfo,
305                        void *puc)
306 {
307     siginfo_t *info = pinfo;
308     unsigned long pc;
309 #if defined(__NetBSD__) || defined(__FreeBSD__) || defined(__DragonFly__)
310     ucontext_t *uc = puc;
311 #elif defined(__OpenBSD__)
312     struct sigcontext *uc = puc;
313 #else
314     ucontext_t *uc = puc;
315 #endif
316 
317     pc = PC_sig(uc);
318     return handle_cpu_signal(pc, info,
319                              TRAP_sig(uc) == 0xe ? (ERROR_sig(uc) >> 1) & 1 : 0,
320                              &MASK_sig(uc));
321 }
322 
323 #elif defined(_ARCH_PPC)
324 
325 /***********************************************************************
326  * signal context platform-specific definitions
327  * From Wine
328  */
329 #ifdef linux
330 /* All Registers access - only for local access */
331 #define REG_sig(reg_name, context)              \
332     ((context)->uc_mcontext.regs->reg_name)
333 /* Gpr Registers access  */
334 #define GPR_sig(reg_num, context)              REG_sig(gpr[reg_num], context)
335 /* Program counter */
336 #define IAR_sig(context)                       REG_sig(nip, context)
337 /* Machine State Register (Supervisor) */
338 #define MSR_sig(context)                       REG_sig(msr, context)
339 /* Count register */
340 #define CTR_sig(context)                       REG_sig(ctr, context)
341 /* User's integer exception register */
342 #define XER_sig(context)                       REG_sig(xer, context)
343 /* Link register */
344 #define LR_sig(context)                        REG_sig(link, context)
345 /* Condition register */
346 #define CR_sig(context)                        REG_sig(ccr, context)
347 
348 /* Float Registers access  */
349 #define FLOAT_sig(reg_num, context)                                     \
350     (((double *)((char *)((context)->uc_mcontext.regs + 48 * 4)))[reg_num])
351 #define FPSCR_sig(context) \
352     (*(int *)((char *)((context)->uc_mcontext.regs + (48 + 32 * 2) * 4)))
353 /* Exception Registers access */
354 #define DAR_sig(context)                       REG_sig(dar, context)
355 #define DSISR_sig(context)                     REG_sig(dsisr, context)
356 #define TRAP_sig(context)                      REG_sig(trap, context)
357 #endif /* linux */
358 
359 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
360 #include <ucontext.h>
361 #define IAR_sig(context)               ((context)->uc_mcontext.mc_srr0)
362 #define MSR_sig(context)               ((context)->uc_mcontext.mc_srr1)
363 #define CTR_sig(context)               ((context)->uc_mcontext.mc_ctr)
364 #define XER_sig(context)               ((context)->uc_mcontext.mc_xer)
365 #define LR_sig(context)                ((context)->uc_mcontext.mc_lr)
366 #define CR_sig(context)                ((context)->uc_mcontext.mc_cr)
367 /* Exception Registers access */
368 #define DAR_sig(context)               ((context)->uc_mcontext.mc_dar)
369 #define DSISR_sig(context)             ((context)->uc_mcontext.mc_dsisr)
370 #define TRAP_sig(context)              ((context)->uc_mcontext.mc_exc)
371 #endif /* __FreeBSD__|| __FreeBSD_kernel__ */
372 
373 int cpu_signal_handler(int host_signum, void *pinfo,
374                        void *puc)
375 {
376     siginfo_t *info = pinfo;
377 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
378     ucontext_t *uc = puc;
379 #else
380     ucontext_t *uc = puc;
381 #endif
382     unsigned long pc;
383     int is_write;
384 
385     pc = IAR_sig(uc);
386     is_write = 0;
387 #if 0
388     /* ppc 4xx case */
389     if (DSISR_sig(uc) & 0x00800000) {
390         is_write = 1;
391     }
392 #else
393     if (TRAP_sig(uc) != 0x400 && (DSISR_sig(uc) & 0x02000000)) {
394         is_write = 1;
395     }
396 #endif
397     return handle_cpu_signal(pc, info, is_write, &uc->uc_sigmask);
398 }
399 
400 #elif defined(__alpha__)
401 
402 int cpu_signal_handler(int host_signum, void *pinfo,
403                            void *puc)
404 {
405     siginfo_t *info = pinfo;
406     ucontext_t *uc = puc;
407     uint32_t *pc = uc->uc_mcontext.sc_pc;
408     uint32_t insn = *pc;
409     int is_write = 0;
410 
411     /* XXX: need kernel patch to get write flag faster */
412     switch (insn >> 26) {
413     case 0x0d: /* stw */
414     case 0x0e: /* stb */
415     case 0x0f: /* stq_u */
416     case 0x24: /* stf */
417     case 0x25: /* stg */
418     case 0x26: /* sts */
419     case 0x27: /* stt */
420     case 0x2c: /* stl */
421     case 0x2d: /* stq */
422     case 0x2e: /* stl_c */
423     case 0x2f: /* stq_c */
424         is_write = 1;
425     }
426 
427     return handle_cpu_signal(pc, info, is_write, &uc->uc_sigmask);
428 }
429 #elif defined(__sparc__)
430 
431 int cpu_signal_handler(int host_signum, void *pinfo,
432                        void *puc)
433 {
434     siginfo_t *info = pinfo;
435     int is_write;
436     uint32_t insn;
437 #if !defined(__arch64__) || defined(CONFIG_SOLARIS)
438     uint32_t *regs = (uint32_t *)(info + 1);
439     void *sigmask = (regs + 20);
440     /* XXX: is there a standard glibc define ? */
441     unsigned long pc = regs[1];
442 #else
443 #ifdef __linux__
444     struct sigcontext *sc = puc;
445     unsigned long pc = sc->sigc_regs.tpc;
446     void *sigmask = (void *)sc->sigc_mask;
447 #elif defined(__OpenBSD__)
448     struct sigcontext *uc = puc;
449     unsigned long pc = uc->sc_pc;
450     void *sigmask = (void *)(long)uc->sc_mask;
451 #elif defined(__NetBSD__)
452     ucontext_t *uc = puc;
453     unsigned long pc = _UC_MACHINE_PC(uc);
454     void *sigmask = (void *)&uc->uc_sigmask;
455 #endif
456 #endif
457 
458     /* XXX: need kernel patch to get write flag faster */
459     is_write = 0;
460     insn = *(uint32_t *)pc;
461     if ((insn >> 30) == 3) {
462         switch ((insn >> 19) & 0x3f) {
463         case 0x05: /* stb */
464         case 0x15: /* stba */
465         case 0x06: /* sth */
466         case 0x16: /* stha */
467         case 0x04: /* st */
468         case 0x14: /* sta */
469         case 0x07: /* std */
470         case 0x17: /* stda */
471         case 0x0e: /* stx */
472         case 0x1e: /* stxa */
473         case 0x24: /* stf */
474         case 0x34: /* stfa */
475         case 0x27: /* stdf */
476         case 0x37: /* stdfa */
477         case 0x26: /* stqf */
478         case 0x36: /* stqfa */
479         case 0x25: /* stfsr */
480         case 0x3c: /* casa */
481         case 0x3e: /* casxa */
482             is_write = 1;
483             break;
484         }
485     }
486     return handle_cpu_signal(pc, info, is_write, sigmask);
487 }
488 
489 #elif defined(__arm__)
490 
491 #if defined(__NetBSD__)
492 #include <ucontext.h>
493 #endif
494 
495 int cpu_signal_handler(int host_signum, void *pinfo,
496                        void *puc)
497 {
498     siginfo_t *info = pinfo;
499 #if defined(__NetBSD__)
500     ucontext_t *uc = puc;
501 #else
502     ucontext_t *uc = puc;
503 #endif
504     unsigned long pc;
505     int is_write;
506 
507 #if defined(__NetBSD__)
508     pc = uc->uc_mcontext.__gregs[_REG_R15];
509 #elif defined(__GLIBC__) && (__GLIBC__ < 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ <= 3))
510     pc = uc->uc_mcontext.gregs[R15];
511 #else
512     pc = uc->uc_mcontext.arm_pc;
513 #endif
514 
515     /* error_code is the FSR value, in which bit 11 is WnR (assuming a v6 or
516      * later processor; on v5 we will always report this as a read).
517      */
518     is_write = extract32(uc->uc_mcontext.error_code, 11, 1);
519     return handle_cpu_signal(pc, info, is_write, &uc->uc_sigmask);
520 }
521 
522 #elif defined(__aarch64__)
523 
524 #ifndef ESR_MAGIC
525 /* Pre-3.16 kernel headers don't have these, so provide fallback definitions */
526 #define ESR_MAGIC 0x45535201
527 struct esr_context {
528     struct _aarch64_ctx head;
529     uint64_t esr;
530 };
531 #endif
532 
533 static inline struct _aarch64_ctx *first_ctx(ucontext_t *uc)
534 {
535     return (struct _aarch64_ctx *)&uc->uc_mcontext.__reserved;
536 }
537 
538 static inline struct _aarch64_ctx *next_ctx(struct _aarch64_ctx *hdr)
539 {
540     return (struct _aarch64_ctx *)((char *)hdr + hdr->size);
541 }
542 
543 int cpu_signal_handler(int host_signum, void *pinfo, void *puc)
544 {
545     siginfo_t *info = pinfo;
546     ucontext_t *uc = puc;
547     uintptr_t pc = uc->uc_mcontext.pc;
548     bool is_write;
549     struct _aarch64_ctx *hdr;
550     struct esr_context const *esrctx = NULL;
551 
552     /* Find the esr_context, which has the WnR bit in it */
553     for (hdr = first_ctx(uc); hdr->magic; hdr = next_ctx(hdr)) {
554         if (hdr->magic == ESR_MAGIC) {
555             esrctx = (struct esr_context const *)hdr;
556             break;
557         }
558     }
559 
560     if (esrctx) {
561         /* For data aborts ESR.EC is 0b10010x: then bit 6 is the WnR bit */
562         uint64_t esr = esrctx->esr;
563         is_write = extract32(esr, 27, 5) == 0x12 && extract32(esr, 6, 1) == 1;
564     } else {
565         /*
566          * Fall back to parsing instructions; will only be needed
567          * for really ancient (pre-3.16) kernels.
568          */
569         uint32_t insn = *(uint32_t *)pc;
570 
571         is_write = ((insn & 0xbfff0000) == 0x0c000000   /* C3.3.1 */
572                     || (insn & 0xbfe00000) == 0x0c800000   /* C3.3.2 */
573                     || (insn & 0xbfdf0000) == 0x0d000000   /* C3.3.3 */
574                     || (insn & 0xbfc00000) == 0x0d800000   /* C3.3.4 */
575                     || (insn & 0x3f400000) == 0x08000000   /* C3.3.6 */
576                     || (insn & 0x3bc00000) == 0x39000000   /* C3.3.13 */
577                     || (insn & 0x3fc00000) == 0x3d800000   /* ... 128bit */
578                     /* Ignore bits 10, 11 & 21, controlling indexing.  */
579                     || (insn & 0x3bc00000) == 0x38000000   /* C3.3.8-12 */
580                     || (insn & 0x3fe00000) == 0x3c800000   /* ... 128bit */
581                     /* Ignore bits 23 & 24, controlling indexing.  */
582                     || (insn & 0x3a400000) == 0x28000000); /* C3.3.7,14-16 */
583     }
584     return handle_cpu_signal(pc, info, is_write, &uc->uc_sigmask);
585 }
586 
587 #elif defined(__s390__)
588 
589 int cpu_signal_handler(int host_signum, void *pinfo,
590                        void *puc)
591 {
592     siginfo_t *info = pinfo;
593     ucontext_t *uc = puc;
594     unsigned long pc;
595     uint16_t *pinsn;
596     int is_write = 0;
597 
598     pc = uc->uc_mcontext.psw.addr;
599 
600     /* ??? On linux, the non-rt signal handler has 4 (!) arguments instead
601        of the normal 2 arguments.  The 3rd argument contains the "int_code"
602        from the hardware which does in fact contain the is_write value.
603        The rt signal handler, as far as I can tell, does not give this value
604        at all.  Not that we could get to it from here even if it were.  */
605     /* ??? This is not even close to complete, since it ignores all
606        of the read-modify-write instructions.  */
607     pinsn = (uint16_t *)pc;
608     switch (pinsn[0] >> 8) {
609     case 0x50: /* ST */
610     case 0x42: /* STC */
611     case 0x40: /* STH */
612         is_write = 1;
613         break;
614     case 0xc4: /* RIL format insns */
615         switch (pinsn[0] & 0xf) {
616         case 0xf: /* STRL */
617         case 0xb: /* STGRL */
618         case 0x7: /* STHRL */
619             is_write = 1;
620         }
621         break;
622     case 0xe3: /* RXY format insns */
623         switch (pinsn[2] & 0xff) {
624         case 0x50: /* STY */
625         case 0x24: /* STG */
626         case 0x72: /* STCY */
627         case 0x70: /* STHY */
628         case 0x8e: /* STPQ */
629         case 0x3f: /* STRVH */
630         case 0x3e: /* STRV */
631         case 0x2f: /* STRVG */
632             is_write = 1;
633         }
634         break;
635     }
636     return handle_cpu_signal(pc, info, is_write, &uc->uc_sigmask);
637 }
638 
639 #elif defined(__mips__)
640 
641 int cpu_signal_handler(int host_signum, void *pinfo,
642                        void *puc)
643 {
644     siginfo_t *info = pinfo;
645     ucontext_t *uc = puc;
646     greg_t pc = uc->uc_mcontext.pc;
647     int is_write;
648 
649     /* XXX: compute is_write */
650     is_write = 0;
651     return handle_cpu_signal(pc, info, is_write, &uc->uc_sigmask);
652 }
653 
654 #elif defined(__riscv)
655 
656 int cpu_signal_handler(int host_signum, void *pinfo,
657                        void *puc)
658 {
659     siginfo_t *info = pinfo;
660     ucontext_t *uc = puc;
661     greg_t pc = uc->uc_mcontext.__gregs[REG_PC];
662     uint32_t insn = *(uint32_t *)pc;
663     int is_write = 0;
664 
665     /* Detect store by reading the instruction at the program
666        counter. Note: we currently only generate 32-bit
667        instructions so we thus only detect 32-bit stores */
668     switch (((insn >> 0) & 0b11)) {
669     case 3:
670         switch (((insn >> 2) & 0b11111)) {
671         case 8:
672             switch (((insn >> 12) & 0b111)) {
673             case 0: /* sb */
674             case 1: /* sh */
675             case 2: /* sw */
676             case 3: /* sd */
677             case 4: /* sq */
678                 is_write = 1;
679                 break;
680             default:
681                 break;
682             }
683             break;
684         case 9:
685             switch (((insn >> 12) & 0b111)) {
686             case 2: /* fsw */
687             case 3: /* fsd */
688             case 4: /* fsq */
689                 is_write = 1;
690                 break;
691             default:
692                 break;
693             }
694             break;
695         default:
696             break;
697         }
698     }
699 
700     /* Check for compressed instructions */
701     switch (((insn >> 13) & 0b111)) {
702     case 7:
703         switch (insn & 0b11) {
704         case 0: /*c.sd */
705         case 2: /* c.sdsp */
706             is_write = 1;
707             break;
708         default:
709             break;
710         }
711         break;
712     case 6:
713         switch (insn & 0b11) {
714         case 0: /* c.sw */
715         case 3: /* c.swsp */
716             is_write = 1;
717             break;
718         default:
719             break;
720         }
721         break;
722     default:
723         break;
724     }
725 
726     return handle_cpu_signal(pc, info, is_write, &uc->uc_sigmask);
727 }
728 
729 #else
730 
731 #error host CPU specific signal handler needed
732 
733 #endif
734 
735 /* The softmmu versions of these helpers are in cputlb.c.  */
736 
737 /* Do not allow unaligned operations to proceed.  Return the host address.  */
738 static void *atomic_mmu_lookup(CPUArchState *env, target_ulong addr,
739                                int size, uintptr_t retaddr)
740 {
741     /* Enforce qemu required alignment.  */
742     if (unlikely(addr & (size - 1))) {
743         cpu_loop_exit_atomic(env_cpu(env), retaddr);
744     }
745     void *ret = g2h(addr);
746     set_helper_retaddr(retaddr);
747     return ret;
748 }
749 
750 /* Macro to call the above, with local variables from the use context.  */
751 #define ATOMIC_MMU_DECLS do {} while (0)
752 #define ATOMIC_MMU_LOOKUP  atomic_mmu_lookup(env, addr, DATA_SIZE, GETPC())
753 #define ATOMIC_MMU_CLEANUP do { clear_helper_retaddr(); } while (0)
754 
755 #define ATOMIC_NAME(X)   HELPER(glue(glue(atomic_ ## X, SUFFIX), END))
756 #define EXTRA_ARGS
757 
758 #define DATA_SIZE 1
759 #include "atomic_template.h"
760 
761 #define DATA_SIZE 2
762 #include "atomic_template.h"
763 
764 #define DATA_SIZE 4
765 #include "atomic_template.h"
766 
767 #ifdef CONFIG_ATOMIC64
768 #define DATA_SIZE 8
769 #include "atomic_template.h"
770 #endif
771 
772 /* The following is only callable from other helpers, and matches up
773    with the softmmu version.  */
774 
775 #if HAVE_ATOMIC128 || HAVE_CMPXCHG128
776 
777 #undef EXTRA_ARGS
778 #undef ATOMIC_NAME
779 #undef ATOMIC_MMU_LOOKUP
780 
781 #define EXTRA_ARGS     , TCGMemOpIdx oi, uintptr_t retaddr
782 #define ATOMIC_NAME(X) \
783     HELPER(glue(glue(glue(atomic_ ## X, SUFFIX), END), _mmu))
784 #define ATOMIC_MMU_LOOKUP  atomic_mmu_lookup(env, addr, DATA_SIZE, retaddr)
785 
786 #define DATA_SIZE 16
787 #include "atomic_template.h"
788 #endif
789