xref: /openbmc/qemu/accel/tcg/user-exec.c (revision 0c4e9931)
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/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 #include "trace-root.h"
30 #include "trace/mem.h"
31 
32 #undef EAX
33 #undef ECX
34 #undef EDX
35 #undef EBX
36 #undef ESP
37 #undef EBP
38 #undef ESI
39 #undef EDI
40 #undef EIP
41 #ifdef __linux__
42 #include <sys/ucontext.h>
43 #endif
44 
45 __thread uintptr_t helper_retaddr;
46 
47 //#define DEBUG_SIGNAL
48 
49 /* exit the current TB from a signal handler. The host registers are
50    restored in a state compatible with the CPU emulator
51  */
52 static void cpu_exit_tb_from_sighandler(CPUState *cpu, sigset_t *old_set)
53 {
54     /* XXX: use siglongjmp ? */
55     sigprocmask(SIG_SETMASK, old_set, NULL);
56     cpu_loop_exit_noexc(cpu);
57 }
58 
59 /* 'pc' is the host PC at which the exception was raised. 'address' is
60    the effective address of the memory exception. 'is_write' is 1 if a
61    write caused the exception and otherwise 0'. 'old_set' is the
62    signal set which should be restored */
63 static inline int handle_cpu_signal(uintptr_t pc, siginfo_t *info,
64                                     int is_write, sigset_t *old_set)
65 {
66     CPUState *cpu = current_cpu;
67     CPUClass *cc;
68     unsigned long address = (unsigned long)info->si_addr;
69     MMUAccessType access_type = is_write ? MMU_DATA_STORE : MMU_DATA_LOAD;
70 
71     switch (helper_retaddr) {
72     default:
73         /*
74          * Fault during host memory operation within a helper function.
75          * The helper's host return address, saved here, gives us a
76          * pointer into the generated code that will unwind to the
77          * correct guest pc.
78          */
79         pc = helper_retaddr;
80         break;
81 
82     case 0:
83         /*
84          * Fault during host memory operation within generated code.
85          * (Or, a unrelated bug within qemu, but we can't tell from here).
86          *
87          * We take the host pc from the signal frame.  However, we cannot
88          * use that value directly.  Within cpu_restore_state_from_tb, we
89          * assume PC comes from GETPC(), as used by the helper functions,
90          * so we adjust the address by -GETPC_ADJ to form an address that
91          * is within the call insn, so that the address does not accidentially
92          * match the beginning of the next guest insn.  However, when the
93          * pc comes from the signal frame it points to the actual faulting
94          * host memory insn and not the return from a call insn.
95          *
96          * Therefore, adjust to compensate for what will be done later
97          * by cpu_restore_state_from_tb.
98          */
99         pc += GETPC_ADJ;
100         break;
101 
102     case 1:
103         /*
104          * Fault during host read for translation, or loosely, "execution".
105          *
106          * The guest pc is already pointing to the start of the TB for which
107          * code is being generated.  If the guest translator manages the
108          * page crossings correctly, this is exactly the correct address
109          * (and if the translator doesn't handle page boundaries correctly
110          * there's little we can do about that here).  Therefore, do not
111          * trigger the unwinder.
112          *
113          * Like tb_gen_code, release the memory lock before cpu_loop_exit.
114          */
115         pc = 0;
116         access_type = MMU_INST_FETCH;
117         mmap_unlock();
118         break;
119     }
120 
121     /* For synchronous signals we expect to be coming from the vCPU
122      * thread (so current_cpu should be valid) and either from running
123      * code or during translation which can fault as we cross pages.
124      *
125      * If neither is true then something has gone wrong and we should
126      * abort rather than try and restart the vCPU execution.
127      */
128     if (!cpu || !cpu->running) {
129         printf("qemu:%s received signal outside vCPU context @ pc=0x%"
130                PRIxPTR "\n",  __func__, pc);
131         abort();
132     }
133 
134 #if defined(DEBUG_SIGNAL)
135     printf("qemu: SIGSEGV pc=0x%08lx address=%08lx w=%d oldset=0x%08lx\n",
136            pc, address, is_write, *(unsigned long *)old_set);
137 #endif
138     /* XXX: locking issue */
139     /* Note that it is important that we don't call page_unprotect() unless
140      * this is really a "write to nonwriteable page" fault, because
141      * page_unprotect() assumes that if it is called for an access to
142      * a page that's writeable this means we had two threads racing and
143      * another thread got there first and already made the page writeable;
144      * so we will retry the access. If we were to call page_unprotect()
145      * for some other kind of fault that should really be passed to the
146      * guest, we'd end up in an infinite loop of retrying the faulting
147      * access.
148      */
149     if (is_write && info->si_signo == SIGSEGV && info->si_code == SEGV_ACCERR &&
150         h2g_valid(address)) {
151         switch (page_unprotect(h2g(address), pc)) {
152         case 0:
153             /* Fault not caused by a page marked unwritable to protect
154              * cached translations, must be the guest binary's problem.
155              */
156             break;
157         case 1:
158             /* Fault caused by protection of cached translation; TBs
159              * invalidated, so resume execution.  Retain helper_retaddr
160              * for a possible second fault.
161              */
162             return 1;
163         case 2:
164             /* Fault caused by protection of cached translation, and the
165              * currently executing TB was modified and must be exited
166              * immediately.  Clear helper_retaddr for next execution.
167              */
168             clear_helper_retaddr();
169             cpu_exit_tb_from_sighandler(cpu, old_set);
170             /* NORETURN */
171 
172         default:
173             g_assert_not_reached();
174         }
175     }
176 
177     /* Convert forcefully to guest address space, invalid addresses
178        are still valid segv ones */
179     address = h2g_nocheck(address);
180 
181     /*
182      * There is no way the target can handle this other than raising
183      * an exception.  Undo signal and retaddr state prior to longjmp.
184      */
185     sigprocmask(SIG_SETMASK, old_set, NULL);
186     clear_helper_retaddr();
187 
188     cc = CPU_GET_CLASS(cpu);
189     cc->tlb_fill(cpu, address, 0, access_type, MMU_USER_IDX, false, pc);
190     g_assert_not_reached();
191 }
192 
193 static int probe_access_internal(CPUArchState *env, target_ulong addr,
194                                  int fault_size, MMUAccessType access_type,
195                                  bool nonfault, uintptr_t ra)
196 {
197     int flags;
198 
199     switch (access_type) {
200     case MMU_DATA_STORE:
201         flags = PAGE_WRITE;
202         break;
203     case MMU_DATA_LOAD:
204         flags = PAGE_READ;
205         break;
206     case MMU_INST_FETCH:
207         flags = PAGE_EXEC;
208         break;
209     default:
210         g_assert_not_reached();
211     }
212 
213     if (!guest_addr_valid(addr) || page_check_range(addr, 1, flags) < 0) {
214         if (nonfault) {
215             return TLB_INVALID_MASK;
216         } else {
217             CPUState *cpu = env_cpu(env);
218             CPUClass *cc = CPU_GET_CLASS(cpu);
219             cc->tlb_fill(cpu, addr, fault_size, access_type,
220                          MMU_USER_IDX, false, ra);
221             g_assert_not_reached();
222         }
223     }
224     return 0;
225 }
226 
227 int probe_access_flags(CPUArchState *env, target_ulong addr,
228                        MMUAccessType access_type, int mmu_idx,
229                        bool nonfault, void **phost, uintptr_t ra)
230 {
231     int flags;
232 
233     flags = probe_access_internal(env, addr, 0, access_type, nonfault, ra);
234     *phost = flags ? NULL : g2h(addr);
235     return flags;
236 }
237 
238 void *probe_access(CPUArchState *env, target_ulong addr, int size,
239                    MMUAccessType access_type, int mmu_idx, uintptr_t ra)
240 {
241     int flags;
242 
243     g_assert(-(addr | TARGET_PAGE_MASK) >= size);
244     flags = probe_access_internal(env, addr, size, access_type, false, ra);
245     g_assert(flags == 0);
246 
247     return size ? g2h(addr) : NULL;
248 }
249 
250 #if defined(__i386__)
251 
252 #if defined(__NetBSD__)
253 #include <ucontext.h>
254 
255 #define EIP_sig(context)     ((context)->uc_mcontext.__gregs[_REG_EIP])
256 #define TRAP_sig(context)    ((context)->uc_mcontext.__gregs[_REG_TRAPNO])
257 #define ERROR_sig(context)   ((context)->uc_mcontext.__gregs[_REG_ERR])
258 #define MASK_sig(context)    ((context)->uc_sigmask)
259 #elif defined(__FreeBSD__) || defined(__DragonFly__)
260 #include <ucontext.h>
261 
262 #define EIP_sig(context)  (*((unsigned long *)&(context)->uc_mcontext.mc_eip))
263 #define TRAP_sig(context)    ((context)->uc_mcontext.mc_trapno)
264 #define ERROR_sig(context)   ((context)->uc_mcontext.mc_err)
265 #define MASK_sig(context)    ((context)->uc_sigmask)
266 #elif defined(__OpenBSD__)
267 #define EIP_sig(context)     ((context)->sc_eip)
268 #define TRAP_sig(context)    ((context)->sc_trapno)
269 #define ERROR_sig(context)   ((context)->sc_err)
270 #define MASK_sig(context)    ((context)->sc_mask)
271 #else
272 #define EIP_sig(context)     ((context)->uc_mcontext.gregs[REG_EIP])
273 #define TRAP_sig(context)    ((context)->uc_mcontext.gregs[REG_TRAPNO])
274 #define ERROR_sig(context)   ((context)->uc_mcontext.gregs[REG_ERR])
275 #define MASK_sig(context)    ((context)->uc_sigmask)
276 #endif
277 
278 int cpu_signal_handler(int host_signum, void *pinfo,
279                        void *puc)
280 {
281     siginfo_t *info = pinfo;
282 #if defined(__NetBSD__) || defined(__FreeBSD__) || defined(__DragonFly__)
283     ucontext_t *uc = puc;
284 #elif defined(__OpenBSD__)
285     struct sigcontext *uc = puc;
286 #else
287     ucontext_t *uc = puc;
288 #endif
289     unsigned long pc;
290     int trapno;
291 
292 #ifndef REG_EIP
293 /* for glibc 2.1 */
294 #define REG_EIP    EIP
295 #define REG_ERR    ERR
296 #define REG_TRAPNO TRAPNO
297 #endif
298     pc = EIP_sig(uc);
299     trapno = TRAP_sig(uc);
300     return handle_cpu_signal(pc, info,
301                              trapno == 0xe ? (ERROR_sig(uc) >> 1) & 1 : 0,
302                              &MASK_sig(uc));
303 }
304 
305 #elif defined(__x86_64__)
306 
307 #ifdef __NetBSD__
308 #define PC_sig(context)       _UC_MACHINE_PC(context)
309 #define TRAP_sig(context)     ((context)->uc_mcontext.__gregs[_REG_TRAPNO])
310 #define ERROR_sig(context)    ((context)->uc_mcontext.__gregs[_REG_ERR])
311 #define MASK_sig(context)     ((context)->uc_sigmask)
312 #elif defined(__OpenBSD__)
313 #define PC_sig(context)       ((context)->sc_rip)
314 #define TRAP_sig(context)     ((context)->sc_trapno)
315 #define ERROR_sig(context)    ((context)->sc_err)
316 #define MASK_sig(context)     ((context)->sc_mask)
317 #elif defined(__FreeBSD__) || defined(__DragonFly__)
318 #include <ucontext.h>
319 
320 #define PC_sig(context)  (*((unsigned long *)&(context)->uc_mcontext.mc_rip))
321 #define TRAP_sig(context)     ((context)->uc_mcontext.mc_trapno)
322 #define ERROR_sig(context)    ((context)->uc_mcontext.mc_err)
323 #define MASK_sig(context)     ((context)->uc_sigmask)
324 #else
325 #define PC_sig(context)       ((context)->uc_mcontext.gregs[REG_RIP])
326 #define TRAP_sig(context)     ((context)->uc_mcontext.gregs[REG_TRAPNO])
327 #define ERROR_sig(context)    ((context)->uc_mcontext.gregs[REG_ERR])
328 #define MASK_sig(context)     ((context)->uc_sigmask)
329 #endif
330 
331 int cpu_signal_handler(int host_signum, void *pinfo,
332                        void *puc)
333 {
334     siginfo_t *info = pinfo;
335     unsigned long pc;
336 #if defined(__NetBSD__) || defined(__FreeBSD__) || defined(__DragonFly__)
337     ucontext_t *uc = puc;
338 #elif defined(__OpenBSD__)
339     struct sigcontext *uc = puc;
340 #else
341     ucontext_t *uc = puc;
342 #endif
343 
344     pc = PC_sig(uc);
345     return handle_cpu_signal(pc, info,
346                              TRAP_sig(uc) == 0xe ? (ERROR_sig(uc) >> 1) & 1 : 0,
347                              &MASK_sig(uc));
348 }
349 
350 #elif defined(_ARCH_PPC)
351 
352 /***********************************************************************
353  * signal context platform-specific definitions
354  * From Wine
355  */
356 #ifdef linux
357 /* All Registers access - only for local access */
358 #define REG_sig(reg_name, context)              \
359     ((context)->uc_mcontext.regs->reg_name)
360 /* Gpr Registers access  */
361 #define GPR_sig(reg_num, context)              REG_sig(gpr[reg_num], context)
362 /* Program counter */
363 #define IAR_sig(context)                       REG_sig(nip, context)
364 /* Machine State Register (Supervisor) */
365 #define MSR_sig(context)                       REG_sig(msr, context)
366 /* Count register */
367 #define CTR_sig(context)                       REG_sig(ctr, context)
368 /* User's integer exception register */
369 #define XER_sig(context)                       REG_sig(xer, context)
370 /* Link register */
371 #define LR_sig(context)                        REG_sig(link, context)
372 /* Condition register */
373 #define CR_sig(context)                        REG_sig(ccr, context)
374 
375 /* Float Registers access  */
376 #define FLOAT_sig(reg_num, context)                                     \
377     (((double *)((char *)((context)->uc_mcontext.regs + 48 * 4)))[reg_num])
378 #define FPSCR_sig(context) \
379     (*(int *)((char *)((context)->uc_mcontext.regs + (48 + 32 * 2) * 4)))
380 /* Exception Registers access */
381 #define DAR_sig(context)                       REG_sig(dar, context)
382 #define DSISR_sig(context)                     REG_sig(dsisr, context)
383 #define TRAP_sig(context)                      REG_sig(trap, context)
384 #endif /* linux */
385 
386 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
387 #include <ucontext.h>
388 #define IAR_sig(context)               ((context)->uc_mcontext.mc_srr0)
389 #define MSR_sig(context)               ((context)->uc_mcontext.mc_srr1)
390 #define CTR_sig(context)               ((context)->uc_mcontext.mc_ctr)
391 #define XER_sig(context)               ((context)->uc_mcontext.mc_xer)
392 #define LR_sig(context)                ((context)->uc_mcontext.mc_lr)
393 #define CR_sig(context)                ((context)->uc_mcontext.mc_cr)
394 /* Exception Registers access */
395 #define DAR_sig(context)               ((context)->uc_mcontext.mc_dar)
396 #define DSISR_sig(context)             ((context)->uc_mcontext.mc_dsisr)
397 #define TRAP_sig(context)              ((context)->uc_mcontext.mc_exc)
398 #endif /* __FreeBSD__|| __FreeBSD_kernel__ */
399 
400 int cpu_signal_handler(int host_signum, void *pinfo,
401                        void *puc)
402 {
403     siginfo_t *info = pinfo;
404 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
405     ucontext_t *uc = puc;
406 #else
407     ucontext_t *uc = puc;
408 #endif
409     unsigned long pc;
410     int is_write;
411 
412     pc = IAR_sig(uc);
413     is_write = 0;
414 #if 0
415     /* ppc 4xx case */
416     if (DSISR_sig(uc) & 0x00800000) {
417         is_write = 1;
418     }
419 #else
420     if (TRAP_sig(uc) != 0x400 && (DSISR_sig(uc) & 0x02000000)) {
421         is_write = 1;
422     }
423 #endif
424     return handle_cpu_signal(pc, info, is_write, &uc->uc_sigmask);
425 }
426 
427 #elif defined(__alpha__)
428 
429 int cpu_signal_handler(int host_signum, void *pinfo,
430                            void *puc)
431 {
432     siginfo_t *info = pinfo;
433     ucontext_t *uc = puc;
434     uint32_t *pc = uc->uc_mcontext.sc_pc;
435     uint32_t insn = *pc;
436     int is_write = 0;
437 
438     /* XXX: need kernel patch to get write flag faster */
439     switch (insn >> 26) {
440     case 0x0d: /* stw */
441     case 0x0e: /* stb */
442     case 0x0f: /* stq_u */
443     case 0x24: /* stf */
444     case 0x25: /* stg */
445     case 0x26: /* sts */
446     case 0x27: /* stt */
447     case 0x2c: /* stl */
448     case 0x2d: /* stq */
449     case 0x2e: /* stl_c */
450     case 0x2f: /* stq_c */
451         is_write = 1;
452     }
453 
454     return handle_cpu_signal(pc, info, is_write, &uc->uc_sigmask);
455 }
456 #elif defined(__sparc__)
457 
458 int cpu_signal_handler(int host_signum, void *pinfo,
459                        void *puc)
460 {
461     siginfo_t *info = pinfo;
462     int is_write;
463     uint32_t insn;
464 #if !defined(__arch64__) || defined(CONFIG_SOLARIS)
465     uint32_t *regs = (uint32_t *)(info + 1);
466     void *sigmask = (regs + 20);
467     /* XXX: is there a standard glibc define ? */
468     unsigned long pc = regs[1];
469 #else
470 #ifdef __linux__
471     struct sigcontext *sc = puc;
472     unsigned long pc = sc->sigc_regs.tpc;
473     void *sigmask = (void *)sc->sigc_mask;
474 #elif defined(__OpenBSD__)
475     struct sigcontext *uc = puc;
476     unsigned long pc = uc->sc_pc;
477     void *sigmask = (void *)(long)uc->sc_mask;
478 #elif defined(__NetBSD__)
479     ucontext_t *uc = puc;
480     unsigned long pc = _UC_MACHINE_PC(uc);
481     void *sigmask = (void *)&uc->uc_sigmask;
482 #endif
483 #endif
484 
485     /* XXX: need kernel patch to get write flag faster */
486     is_write = 0;
487     insn = *(uint32_t *)pc;
488     if ((insn >> 30) == 3) {
489         switch ((insn >> 19) & 0x3f) {
490         case 0x05: /* stb */
491         case 0x15: /* stba */
492         case 0x06: /* sth */
493         case 0x16: /* stha */
494         case 0x04: /* st */
495         case 0x14: /* sta */
496         case 0x07: /* std */
497         case 0x17: /* stda */
498         case 0x0e: /* stx */
499         case 0x1e: /* stxa */
500         case 0x24: /* stf */
501         case 0x34: /* stfa */
502         case 0x27: /* stdf */
503         case 0x37: /* stdfa */
504         case 0x26: /* stqf */
505         case 0x36: /* stqfa */
506         case 0x25: /* stfsr */
507         case 0x3c: /* casa */
508         case 0x3e: /* casxa */
509             is_write = 1;
510             break;
511         }
512     }
513     return handle_cpu_signal(pc, info, is_write, sigmask);
514 }
515 
516 #elif defined(__arm__)
517 
518 #if defined(__NetBSD__)
519 #include <ucontext.h>
520 #endif
521 
522 int cpu_signal_handler(int host_signum, void *pinfo,
523                        void *puc)
524 {
525     siginfo_t *info = pinfo;
526 #if defined(__NetBSD__)
527     ucontext_t *uc = puc;
528 #else
529     ucontext_t *uc = puc;
530 #endif
531     unsigned long pc;
532     int is_write;
533 
534 #if defined(__NetBSD__)
535     pc = uc->uc_mcontext.__gregs[_REG_R15];
536 #elif defined(__GLIBC__) && (__GLIBC__ < 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ <= 3))
537     pc = uc->uc_mcontext.gregs[R15];
538 #else
539     pc = uc->uc_mcontext.arm_pc;
540 #endif
541 
542     /* error_code is the FSR value, in which bit 11 is WnR (assuming a v6 or
543      * later processor; on v5 we will always report this as a read).
544      */
545     is_write = extract32(uc->uc_mcontext.error_code, 11, 1);
546     return handle_cpu_signal(pc, info, is_write, &uc->uc_sigmask);
547 }
548 
549 #elif defined(__aarch64__)
550 
551 #ifndef ESR_MAGIC
552 /* Pre-3.16 kernel headers don't have these, so provide fallback definitions */
553 #define ESR_MAGIC 0x45535201
554 struct esr_context {
555     struct _aarch64_ctx head;
556     uint64_t esr;
557 };
558 #endif
559 
560 static inline struct _aarch64_ctx *first_ctx(ucontext_t *uc)
561 {
562     return (struct _aarch64_ctx *)&uc->uc_mcontext.__reserved;
563 }
564 
565 static inline struct _aarch64_ctx *next_ctx(struct _aarch64_ctx *hdr)
566 {
567     return (struct _aarch64_ctx *)((char *)hdr + hdr->size);
568 }
569 
570 int cpu_signal_handler(int host_signum, void *pinfo, void *puc)
571 {
572     siginfo_t *info = pinfo;
573     ucontext_t *uc = puc;
574     uintptr_t pc = uc->uc_mcontext.pc;
575     bool is_write;
576     struct _aarch64_ctx *hdr;
577     struct esr_context const *esrctx = NULL;
578 
579     /* Find the esr_context, which has the WnR bit in it */
580     for (hdr = first_ctx(uc); hdr->magic; hdr = next_ctx(hdr)) {
581         if (hdr->magic == ESR_MAGIC) {
582             esrctx = (struct esr_context const *)hdr;
583             break;
584         }
585     }
586 
587     if (esrctx) {
588         /* For data aborts ESR.EC is 0b10010x: then bit 6 is the WnR bit */
589         uint64_t esr = esrctx->esr;
590         is_write = extract32(esr, 27, 5) == 0x12 && extract32(esr, 6, 1) == 1;
591     } else {
592         /*
593          * Fall back to parsing instructions; will only be needed
594          * for really ancient (pre-3.16) kernels.
595          */
596         uint32_t insn = *(uint32_t *)pc;
597 
598         is_write = ((insn & 0xbfff0000) == 0x0c000000   /* C3.3.1 */
599                     || (insn & 0xbfe00000) == 0x0c800000   /* C3.3.2 */
600                     || (insn & 0xbfdf0000) == 0x0d000000   /* C3.3.3 */
601                     || (insn & 0xbfc00000) == 0x0d800000   /* C3.3.4 */
602                     || (insn & 0x3f400000) == 0x08000000   /* C3.3.6 */
603                     || (insn & 0x3bc00000) == 0x39000000   /* C3.3.13 */
604                     || (insn & 0x3fc00000) == 0x3d800000   /* ... 128bit */
605                     /* Ignore bits 10, 11 & 21, controlling indexing.  */
606                     || (insn & 0x3bc00000) == 0x38000000   /* C3.3.8-12 */
607                     || (insn & 0x3fe00000) == 0x3c800000   /* ... 128bit */
608                     /* Ignore bits 23 & 24, controlling indexing.  */
609                     || (insn & 0x3a400000) == 0x28000000); /* C3.3.7,14-16 */
610     }
611     return handle_cpu_signal(pc, info, is_write, &uc->uc_sigmask);
612 }
613 
614 #elif defined(__s390__)
615 
616 int cpu_signal_handler(int host_signum, void *pinfo,
617                        void *puc)
618 {
619     siginfo_t *info = pinfo;
620     ucontext_t *uc = puc;
621     unsigned long pc;
622     uint16_t *pinsn;
623     int is_write = 0;
624 
625     pc = uc->uc_mcontext.psw.addr;
626 
627     /* ??? On linux, the non-rt signal handler has 4 (!) arguments instead
628        of the normal 2 arguments.  The 3rd argument contains the "int_code"
629        from the hardware which does in fact contain the is_write value.
630        The rt signal handler, as far as I can tell, does not give this value
631        at all.  Not that we could get to it from here even if it were.  */
632     /* ??? This is not even close to complete, since it ignores all
633        of the read-modify-write instructions.  */
634     pinsn = (uint16_t *)pc;
635     switch (pinsn[0] >> 8) {
636     case 0x50: /* ST */
637     case 0x42: /* STC */
638     case 0x40: /* STH */
639         is_write = 1;
640         break;
641     case 0xc4: /* RIL format insns */
642         switch (pinsn[0] & 0xf) {
643         case 0xf: /* STRL */
644         case 0xb: /* STGRL */
645         case 0x7: /* STHRL */
646             is_write = 1;
647         }
648         break;
649     case 0xe3: /* RXY format insns */
650         switch (pinsn[2] & 0xff) {
651         case 0x50: /* STY */
652         case 0x24: /* STG */
653         case 0x72: /* STCY */
654         case 0x70: /* STHY */
655         case 0x8e: /* STPQ */
656         case 0x3f: /* STRVH */
657         case 0x3e: /* STRV */
658         case 0x2f: /* STRVG */
659             is_write = 1;
660         }
661         break;
662     }
663     return handle_cpu_signal(pc, info, is_write, &uc->uc_sigmask);
664 }
665 
666 #elif defined(__mips__)
667 
668 int cpu_signal_handler(int host_signum, void *pinfo,
669                        void *puc)
670 {
671     siginfo_t *info = pinfo;
672     ucontext_t *uc = puc;
673     greg_t pc = uc->uc_mcontext.pc;
674     int is_write;
675 
676     /* XXX: compute is_write */
677     is_write = 0;
678     return handle_cpu_signal(pc, info, is_write, &uc->uc_sigmask);
679 }
680 
681 #elif defined(__riscv)
682 
683 int cpu_signal_handler(int host_signum, void *pinfo,
684                        void *puc)
685 {
686     siginfo_t *info = pinfo;
687     ucontext_t *uc = puc;
688     greg_t pc = uc->uc_mcontext.__gregs[REG_PC];
689     uint32_t insn = *(uint32_t *)pc;
690     int is_write = 0;
691 
692     /* Detect store by reading the instruction at the program
693        counter. Note: we currently only generate 32-bit
694        instructions so we thus only detect 32-bit stores */
695     switch (((insn >> 0) & 0b11)) {
696     case 3:
697         switch (((insn >> 2) & 0b11111)) {
698         case 8:
699             switch (((insn >> 12) & 0b111)) {
700             case 0: /* sb */
701             case 1: /* sh */
702             case 2: /* sw */
703             case 3: /* sd */
704             case 4: /* sq */
705                 is_write = 1;
706                 break;
707             default:
708                 break;
709             }
710             break;
711         case 9:
712             switch (((insn >> 12) & 0b111)) {
713             case 2: /* fsw */
714             case 3: /* fsd */
715             case 4: /* fsq */
716                 is_write = 1;
717                 break;
718             default:
719                 break;
720             }
721             break;
722         default:
723             break;
724         }
725     }
726 
727     /* Check for compressed instructions */
728     switch (((insn >> 13) & 0b111)) {
729     case 7:
730         switch (insn & 0b11) {
731         case 0: /*c.sd */
732         case 2: /* c.sdsp */
733             is_write = 1;
734             break;
735         default:
736             break;
737         }
738         break;
739     case 6:
740         switch (insn & 0b11) {
741         case 0: /* c.sw */
742         case 3: /* c.swsp */
743             is_write = 1;
744             break;
745         default:
746             break;
747         }
748         break;
749     default:
750         break;
751     }
752 
753     return handle_cpu_signal(pc, info, is_write, &uc->uc_sigmask);
754 }
755 
756 #else
757 
758 #error host CPU specific signal handler needed
759 
760 #endif
761 
762 /* The softmmu versions of these helpers are in cputlb.c.  */
763 
764 uint32_t cpu_ldub_data(CPUArchState *env, abi_ptr ptr)
765 {
766     uint32_t ret;
767     uint16_t meminfo = trace_mem_get_info(MO_UB, MMU_USER_IDX, false);
768 
769     trace_guest_mem_before_exec(env_cpu(env), ptr, meminfo);
770     ret = ldub_p(g2h(ptr));
771     qemu_plugin_vcpu_mem_cb(env_cpu(env), ptr, meminfo);
772     return ret;
773 }
774 
775 int cpu_ldsb_data(CPUArchState *env, abi_ptr ptr)
776 {
777     int ret;
778     uint16_t meminfo = trace_mem_get_info(MO_SB, MMU_USER_IDX, false);
779 
780     trace_guest_mem_before_exec(env_cpu(env), ptr, meminfo);
781     ret = ldsb_p(g2h(ptr));
782     qemu_plugin_vcpu_mem_cb(env_cpu(env), ptr, meminfo);
783     return ret;
784 }
785 
786 uint32_t cpu_lduw_be_data(CPUArchState *env, abi_ptr ptr)
787 {
788     uint32_t ret;
789     uint16_t meminfo = trace_mem_get_info(MO_BEUW, MMU_USER_IDX, false);
790 
791     trace_guest_mem_before_exec(env_cpu(env), ptr, meminfo);
792     ret = lduw_be_p(g2h(ptr));
793     qemu_plugin_vcpu_mem_cb(env_cpu(env), ptr, meminfo);
794     return ret;
795 }
796 
797 int cpu_ldsw_be_data(CPUArchState *env, abi_ptr ptr)
798 {
799     int ret;
800     uint16_t meminfo = trace_mem_get_info(MO_BESW, MMU_USER_IDX, false);
801 
802     trace_guest_mem_before_exec(env_cpu(env), ptr, meminfo);
803     ret = ldsw_be_p(g2h(ptr));
804     qemu_plugin_vcpu_mem_cb(env_cpu(env), ptr, meminfo);
805     return ret;
806 }
807 
808 uint32_t cpu_ldl_be_data(CPUArchState *env, abi_ptr ptr)
809 {
810     uint32_t ret;
811     uint16_t meminfo = trace_mem_get_info(MO_BEUL, MMU_USER_IDX, false);
812 
813     trace_guest_mem_before_exec(env_cpu(env), ptr, meminfo);
814     ret = ldl_be_p(g2h(ptr));
815     qemu_plugin_vcpu_mem_cb(env_cpu(env), ptr, meminfo);
816     return ret;
817 }
818 
819 uint64_t cpu_ldq_be_data(CPUArchState *env, abi_ptr ptr)
820 {
821     uint64_t ret;
822     uint16_t meminfo = trace_mem_get_info(MO_BEQ, MMU_USER_IDX, false);
823 
824     trace_guest_mem_before_exec(env_cpu(env), ptr, meminfo);
825     ret = ldq_be_p(g2h(ptr));
826     qemu_plugin_vcpu_mem_cb(env_cpu(env), ptr, meminfo);
827     return ret;
828 }
829 
830 uint32_t cpu_lduw_le_data(CPUArchState *env, abi_ptr ptr)
831 {
832     uint32_t ret;
833     uint16_t meminfo = trace_mem_get_info(MO_LEUW, MMU_USER_IDX, false);
834 
835     trace_guest_mem_before_exec(env_cpu(env), ptr, meminfo);
836     ret = lduw_le_p(g2h(ptr));
837     qemu_plugin_vcpu_mem_cb(env_cpu(env), ptr, meminfo);
838     return ret;
839 }
840 
841 int cpu_ldsw_le_data(CPUArchState *env, abi_ptr ptr)
842 {
843     int ret;
844     uint16_t meminfo = trace_mem_get_info(MO_LESW, MMU_USER_IDX, false);
845 
846     trace_guest_mem_before_exec(env_cpu(env), ptr, meminfo);
847     ret = ldsw_le_p(g2h(ptr));
848     qemu_plugin_vcpu_mem_cb(env_cpu(env), ptr, meminfo);
849     return ret;
850 }
851 
852 uint32_t cpu_ldl_le_data(CPUArchState *env, abi_ptr ptr)
853 {
854     uint32_t ret;
855     uint16_t meminfo = trace_mem_get_info(MO_LEUL, MMU_USER_IDX, false);
856 
857     trace_guest_mem_before_exec(env_cpu(env), ptr, meminfo);
858     ret = ldl_le_p(g2h(ptr));
859     qemu_plugin_vcpu_mem_cb(env_cpu(env), ptr, meminfo);
860     return ret;
861 }
862 
863 uint64_t cpu_ldq_le_data(CPUArchState *env, abi_ptr ptr)
864 {
865     uint64_t ret;
866     uint16_t meminfo = trace_mem_get_info(MO_LEQ, MMU_USER_IDX, false);
867 
868     trace_guest_mem_before_exec(env_cpu(env), ptr, meminfo);
869     ret = ldq_le_p(g2h(ptr));
870     qemu_plugin_vcpu_mem_cb(env_cpu(env), ptr, meminfo);
871     return ret;
872 }
873 
874 uint32_t cpu_ldub_data_ra(CPUArchState *env, abi_ptr ptr, uintptr_t retaddr)
875 {
876     uint32_t ret;
877 
878     set_helper_retaddr(retaddr);
879     ret = cpu_ldub_data(env, ptr);
880     clear_helper_retaddr();
881     return ret;
882 }
883 
884 int cpu_ldsb_data_ra(CPUArchState *env, abi_ptr ptr, uintptr_t retaddr)
885 {
886     int ret;
887 
888     set_helper_retaddr(retaddr);
889     ret = cpu_ldsb_data(env, ptr);
890     clear_helper_retaddr();
891     return ret;
892 }
893 
894 uint32_t cpu_lduw_be_data_ra(CPUArchState *env, abi_ptr ptr, uintptr_t retaddr)
895 {
896     uint32_t ret;
897 
898     set_helper_retaddr(retaddr);
899     ret = cpu_lduw_be_data(env, ptr);
900     clear_helper_retaddr();
901     return ret;
902 }
903 
904 int cpu_ldsw_be_data_ra(CPUArchState *env, abi_ptr ptr, uintptr_t retaddr)
905 {
906     int ret;
907 
908     set_helper_retaddr(retaddr);
909     ret = cpu_ldsw_be_data(env, ptr);
910     clear_helper_retaddr();
911     return ret;
912 }
913 
914 uint32_t cpu_ldl_be_data_ra(CPUArchState *env, abi_ptr ptr, uintptr_t retaddr)
915 {
916     uint32_t ret;
917 
918     set_helper_retaddr(retaddr);
919     ret = cpu_ldl_be_data(env, ptr);
920     clear_helper_retaddr();
921     return ret;
922 }
923 
924 uint64_t cpu_ldq_be_data_ra(CPUArchState *env, abi_ptr ptr, uintptr_t retaddr)
925 {
926     uint64_t ret;
927 
928     set_helper_retaddr(retaddr);
929     ret = cpu_ldq_be_data(env, ptr);
930     clear_helper_retaddr();
931     return ret;
932 }
933 
934 uint32_t cpu_lduw_le_data_ra(CPUArchState *env, abi_ptr ptr, uintptr_t retaddr)
935 {
936     uint32_t ret;
937 
938     set_helper_retaddr(retaddr);
939     ret = cpu_lduw_le_data(env, ptr);
940     clear_helper_retaddr();
941     return ret;
942 }
943 
944 int cpu_ldsw_le_data_ra(CPUArchState *env, abi_ptr ptr, uintptr_t retaddr)
945 {
946     int ret;
947 
948     set_helper_retaddr(retaddr);
949     ret = cpu_ldsw_le_data(env, ptr);
950     clear_helper_retaddr();
951     return ret;
952 }
953 
954 uint32_t cpu_ldl_le_data_ra(CPUArchState *env, abi_ptr ptr, uintptr_t retaddr)
955 {
956     uint32_t ret;
957 
958     set_helper_retaddr(retaddr);
959     ret = cpu_ldl_le_data(env, ptr);
960     clear_helper_retaddr();
961     return ret;
962 }
963 
964 uint64_t cpu_ldq_le_data_ra(CPUArchState *env, abi_ptr ptr, uintptr_t retaddr)
965 {
966     uint64_t ret;
967 
968     set_helper_retaddr(retaddr);
969     ret = cpu_ldq_le_data(env, ptr);
970     clear_helper_retaddr();
971     return ret;
972 }
973 
974 void cpu_stb_data(CPUArchState *env, abi_ptr ptr, uint32_t val)
975 {
976     uint16_t meminfo = trace_mem_get_info(MO_UB, MMU_USER_IDX, true);
977 
978     trace_guest_mem_before_exec(env_cpu(env), ptr, meminfo);
979     stb_p(g2h(ptr), val);
980     qemu_plugin_vcpu_mem_cb(env_cpu(env), ptr, meminfo);
981 }
982 
983 void cpu_stw_be_data(CPUArchState *env, abi_ptr ptr, uint32_t val)
984 {
985     uint16_t meminfo = trace_mem_get_info(MO_BEUW, MMU_USER_IDX, true);
986 
987     trace_guest_mem_before_exec(env_cpu(env), ptr, meminfo);
988     stw_be_p(g2h(ptr), val);
989     qemu_plugin_vcpu_mem_cb(env_cpu(env), ptr, meminfo);
990 }
991 
992 void cpu_stl_be_data(CPUArchState *env, abi_ptr ptr, uint32_t val)
993 {
994     uint16_t meminfo = trace_mem_get_info(MO_BEUL, MMU_USER_IDX, true);
995 
996     trace_guest_mem_before_exec(env_cpu(env), ptr, meminfo);
997     stl_be_p(g2h(ptr), val);
998     qemu_plugin_vcpu_mem_cb(env_cpu(env), ptr, meminfo);
999 }
1000 
1001 void cpu_stq_be_data(CPUArchState *env, abi_ptr ptr, uint64_t val)
1002 {
1003     uint16_t meminfo = trace_mem_get_info(MO_BEQ, MMU_USER_IDX, true);
1004 
1005     trace_guest_mem_before_exec(env_cpu(env), ptr, meminfo);
1006     stq_be_p(g2h(ptr), val);
1007     qemu_plugin_vcpu_mem_cb(env_cpu(env), ptr, meminfo);
1008 }
1009 
1010 void cpu_stw_le_data(CPUArchState *env, abi_ptr ptr, uint32_t val)
1011 {
1012     uint16_t meminfo = trace_mem_get_info(MO_LEUW, MMU_USER_IDX, true);
1013 
1014     trace_guest_mem_before_exec(env_cpu(env), ptr, meminfo);
1015     stw_le_p(g2h(ptr), val);
1016     qemu_plugin_vcpu_mem_cb(env_cpu(env), ptr, meminfo);
1017 }
1018 
1019 void cpu_stl_le_data(CPUArchState *env, abi_ptr ptr, uint32_t val)
1020 {
1021     uint16_t meminfo = trace_mem_get_info(MO_LEUL, MMU_USER_IDX, true);
1022 
1023     trace_guest_mem_before_exec(env_cpu(env), ptr, meminfo);
1024     stl_le_p(g2h(ptr), val);
1025     qemu_plugin_vcpu_mem_cb(env_cpu(env), ptr, meminfo);
1026 }
1027 
1028 void cpu_stq_le_data(CPUArchState *env, abi_ptr ptr, uint64_t val)
1029 {
1030     uint16_t meminfo = trace_mem_get_info(MO_LEQ, MMU_USER_IDX, true);
1031 
1032     trace_guest_mem_before_exec(env_cpu(env), ptr, meminfo);
1033     stq_le_p(g2h(ptr), val);
1034     qemu_plugin_vcpu_mem_cb(env_cpu(env), ptr, meminfo);
1035 }
1036 
1037 void cpu_stb_data_ra(CPUArchState *env, abi_ptr ptr,
1038                      uint32_t val, uintptr_t retaddr)
1039 {
1040     set_helper_retaddr(retaddr);
1041     cpu_stb_data(env, ptr, val);
1042     clear_helper_retaddr();
1043 }
1044 
1045 void cpu_stw_be_data_ra(CPUArchState *env, abi_ptr ptr,
1046                         uint32_t val, uintptr_t retaddr)
1047 {
1048     set_helper_retaddr(retaddr);
1049     cpu_stw_be_data(env, ptr, val);
1050     clear_helper_retaddr();
1051 }
1052 
1053 void cpu_stl_be_data_ra(CPUArchState *env, abi_ptr ptr,
1054                         uint32_t val, uintptr_t retaddr)
1055 {
1056     set_helper_retaddr(retaddr);
1057     cpu_stl_be_data(env, ptr, val);
1058     clear_helper_retaddr();
1059 }
1060 
1061 void cpu_stq_be_data_ra(CPUArchState *env, abi_ptr ptr,
1062                         uint64_t val, uintptr_t retaddr)
1063 {
1064     set_helper_retaddr(retaddr);
1065     cpu_stq_be_data(env, ptr, val);
1066     clear_helper_retaddr();
1067 }
1068 
1069 void cpu_stw_le_data_ra(CPUArchState *env, abi_ptr ptr,
1070                         uint32_t val, uintptr_t retaddr)
1071 {
1072     set_helper_retaddr(retaddr);
1073     cpu_stw_le_data(env, ptr, val);
1074     clear_helper_retaddr();
1075 }
1076 
1077 void cpu_stl_le_data_ra(CPUArchState *env, abi_ptr ptr,
1078                         uint32_t val, uintptr_t retaddr)
1079 {
1080     set_helper_retaddr(retaddr);
1081     cpu_stl_le_data(env, ptr, val);
1082     clear_helper_retaddr();
1083 }
1084 
1085 void cpu_stq_le_data_ra(CPUArchState *env, abi_ptr ptr,
1086                         uint64_t val, uintptr_t retaddr)
1087 {
1088     set_helper_retaddr(retaddr);
1089     cpu_stq_le_data(env, ptr, val);
1090     clear_helper_retaddr();
1091 }
1092 
1093 uint32_t cpu_ldub_code(CPUArchState *env, abi_ptr ptr)
1094 {
1095     uint32_t ret;
1096 
1097     set_helper_retaddr(1);
1098     ret = ldub_p(g2h(ptr));
1099     clear_helper_retaddr();
1100     return ret;
1101 }
1102 
1103 uint32_t cpu_lduw_code(CPUArchState *env, abi_ptr ptr)
1104 {
1105     uint32_t ret;
1106 
1107     set_helper_retaddr(1);
1108     ret = lduw_p(g2h(ptr));
1109     clear_helper_retaddr();
1110     return ret;
1111 }
1112 
1113 uint32_t cpu_ldl_code(CPUArchState *env, abi_ptr ptr)
1114 {
1115     uint32_t ret;
1116 
1117     set_helper_retaddr(1);
1118     ret = ldl_p(g2h(ptr));
1119     clear_helper_retaddr();
1120     return ret;
1121 }
1122 
1123 uint64_t cpu_ldq_code(CPUArchState *env, abi_ptr ptr)
1124 {
1125     uint64_t ret;
1126 
1127     set_helper_retaddr(1);
1128     ret = ldq_p(g2h(ptr));
1129     clear_helper_retaddr();
1130     return ret;
1131 }
1132 
1133 /* Do not allow unaligned operations to proceed.  Return the host address.  */
1134 static void *atomic_mmu_lookup(CPUArchState *env, target_ulong addr,
1135                                int size, uintptr_t retaddr)
1136 {
1137     /* Enforce qemu required alignment.  */
1138     if (unlikely(addr & (size - 1))) {
1139         cpu_loop_exit_atomic(env_cpu(env), retaddr);
1140     }
1141     void *ret = g2h(addr);
1142     set_helper_retaddr(retaddr);
1143     return ret;
1144 }
1145 
1146 /* Macro to call the above, with local variables from the use context.  */
1147 #define ATOMIC_MMU_DECLS do {} while (0)
1148 #define ATOMIC_MMU_LOOKUP  atomic_mmu_lookup(env, addr, DATA_SIZE, GETPC())
1149 #define ATOMIC_MMU_CLEANUP do { clear_helper_retaddr(); } while (0)
1150 #define ATOMIC_MMU_IDX MMU_USER_IDX
1151 
1152 #define ATOMIC_NAME(X)   HELPER(glue(glue(atomic_ ## X, SUFFIX), END))
1153 #define EXTRA_ARGS
1154 
1155 #include "atomic_common.inc.c"
1156 
1157 #define DATA_SIZE 1
1158 #include "atomic_template.h"
1159 
1160 #define DATA_SIZE 2
1161 #include "atomic_template.h"
1162 
1163 #define DATA_SIZE 4
1164 #include "atomic_template.h"
1165 
1166 #ifdef CONFIG_ATOMIC64
1167 #define DATA_SIZE 8
1168 #include "atomic_template.h"
1169 #endif
1170 
1171 /* The following is only callable from other helpers, and matches up
1172    with the softmmu version.  */
1173 
1174 #if HAVE_ATOMIC128 || HAVE_CMPXCHG128
1175 
1176 #undef EXTRA_ARGS
1177 #undef ATOMIC_NAME
1178 #undef ATOMIC_MMU_LOOKUP
1179 
1180 #define EXTRA_ARGS     , TCGMemOpIdx oi, uintptr_t retaddr
1181 #define ATOMIC_NAME(X) \
1182     HELPER(glue(glue(glue(atomic_ ## X, SUFFIX), END), _mmu))
1183 #define ATOMIC_MMU_LOOKUP  atomic_mmu_lookup(env, addr, DATA_SIZE, retaddr)
1184 
1185 #define DATA_SIZE 16
1186 #include "atomic_template.h"
1187 #endif
1188