xref: /openbmc/qemu/linux-user/sparc/signal.c (revision 743f99e1176b175ff2698d0dc36b834c6cef7f24)
1 /*
2  *  Emulation of Linux signals
3  *
4  *  Copyright (c) 2003 Fabrice Bellard
5  *
6  *  This program is free software; you can redistribute it and/or modify
7  *  it under the terms of the GNU General Public License as published by
8  *  the Free Software Foundation; either version 2 of the License, or
9  *  (at your option) any later version.
10  *
11  *  This program 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
14  *  GNU General Public License for more details.
15  *
16  *  You should have received a copy of the GNU General Public License
17  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
18  */
19 #include "qemu/osdep.h"
20 #include "qemu.h"
21 #include "signal-common.h"
22 #include "linux-user/trace.h"
23 
24 /* A Sparc stack frame */
25 struct sparc_stackf {
26     abi_ulong locals[8];
27     abi_ulong ins[8];
28     /* It's simpler to treat fp and callers_pc as elements of ins[]
29          * since we never need to access them ourselves.
30          */
31     char *structptr;
32     abi_ulong xargs[6];
33     abi_ulong xxargs[1];
34 };
35 
36 typedef struct {
37     struct {
38         abi_ulong psr;
39         abi_ulong pc;
40         abi_ulong npc;
41         abi_ulong y;
42         abi_ulong u_regs[16]; /* globals and ins */
43     }               si_regs;
44     int             si_mask;
45 } __siginfo_t;
46 
47 typedef struct {
48     abi_ulong  si_float_regs[32];
49     unsigned   long si_fsr;
50     unsigned   long si_fpqdepth;
51     struct {
52         unsigned long *insn_addr;
53         unsigned long insn;
54     } si_fpqueue [16];
55 } qemu_siginfo_fpu_t;
56 
57 
58 struct target_signal_frame {
59     struct sparc_stackf ss;
60     __siginfo_t         info;
61     abi_ulong           fpu_save;
62     uint32_t            insns[2] QEMU_ALIGNED(8);
63     abi_ulong           extramask[TARGET_NSIG_WORDS - 1];
64     abi_ulong           extra_size; /* Should be 0 */
65     qemu_siginfo_fpu_t fpu_state;
66 };
67 struct target_rt_signal_frame {
68     struct sparc_stackf ss;
69     siginfo_t           info;
70     abi_ulong           regs[20];
71     sigset_t            mask;
72     abi_ulong           fpu_save;
73     uint32_t            insns[2];
74     stack_t             stack;
75     unsigned int        extra_size; /* Should be 0 */
76     qemu_siginfo_fpu_t  fpu_state;
77 };
78 
79 static inline abi_ulong get_sigframe(struct target_sigaction *sa,
80                                      CPUSPARCState *env,
81                                      unsigned long framesize)
82 {
83     abi_ulong sp = get_sp_from_cpustate(env);
84 
85     /*
86      * If we are on the alternate signal stack and would overflow it, don't.
87      * Return an always-bogus address instead so we will die with SIGSEGV.
88          */
89     if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize))) {
90             return -1;
91     }
92 
93     /* This is the X/Open sanctioned signal stack switching.  */
94     sp = target_sigsp(sp, sa) - framesize;
95 
96     /* Always align the stack frame.  This handles two cases.  First,
97      * sigaltstack need not be mindful of platform specific stack
98      * alignment.  Second, if we took this signal because the stack
99      * is not aligned properly, we'd like to take the signal cleanly
100      * and report that.
101      */
102     sp &= ~15UL;
103 
104     return sp;
105 }
106 
107 static int
108 setup___siginfo(__siginfo_t *si, CPUSPARCState *env, abi_ulong mask)
109 {
110     int err = 0, i;
111 
112     __put_user(env->psr, &si->si_regs.psr);
113     __put_user(env->pc, &si->si_regs.pc);
114     __put_user(env->npc, &si->si_regs.npc);
115     __put_user(env->y, &si->si_regs.y);
116     for (i=0; i < 8; i++) {
117         __put_user(env->gregs[i], &si->si_regs.u_regs[i]);
118     }
119     for (i=0; i < 8; i++) {
120         __put_user(env->regwptr[WREG_O0 + i], &si->si_regs.u_regs[i + 8]);
121     }
122     __put_user(mask, &si->si_mask);
123     return err;
124 }
125 
126 #define NF_ALIGNEDSZ  (((sizeof(struct target_signal_frame) + 7) & (~7)))
127 
128 void setup_frame(int sig, struct target_sigaction *ka,
129                  target_sigset_t *set, CPUSPARCState *env)
130 {
131     abi_ulong sf_addr;
132     struct target_signal_frame *sf;
133     int sigframe_size, err, i;
134 
135     /* 1. Make sure everything is clean */
136     //synchronize_user_stack();
137 
138     sigframe_size = NF_ALIGNEDSZ;
139     sf_addr = get_sigframe(ka, env, sigframe_size);
140     trace_user_setup_frame(env, sf_addr);
141 
142     sf = lock_user(VERIFY_WRITE, sf_addr,
143                    sizeof(struct target_signal_frame), 0);
144     if (!sf) {
145         goto sigsegv;
146     }
147 #if 0
148     if (invalid_frame_pointer(sf, sigframe_size))
149         goto sigill_and_return;
150 #endif
151     /* 2. Save the current process state */
152     err = setup___siginfo(&sf->info, env, set->sig[0]);
153     __put_user(0, &sf->extra_size);
154 
155     //save_fpu_state(regs, &sf->fpu_state);
156     //__put_user(&sf->fpu_state, &sf->fpu_save);
157 
158     __put_user(set->sig[0], &sf->info.si_mask);
159     for (i = 0; i < TARGET_NSIG_WORDS - 1; i++) {
160         __put_user(set->sig[i + 1], &sf->extramask[i]);
161     }
162 
163     for (i = 0; i < 8; i++) {
164         __put_user(env->regwptr[i + WREG_L0], &sf->ss.locals[i]);
165     }
166     for (i = 0; i < 8; i++) {
167         __put_user(env->regwptr[i + WREG_I0], &sf->ss.ins[i]);
168     }
169     if (err)
170         goto sigsegv;
171 
172     /* 3. signal handler back-trampoline and parameters */
173     env->regwptr[WREG_SP] = sf_addr;
174     env->regwptr[WREG_O0] = sig;
175     env->regwptr[WREG_O1] = sf_addr +
176             offsetof(struct target_signal_frame, info);
177     env->regwptr[WREG_O2] = sf_addr +
178             offsetof(struct target_signal_frame, info);
179 
180     /* 4. signal handler */
181     env->pc = ka->_sa_handler;
182     env->npc = (env->pc + 4);
183     /* 5. return to kernel instructions */
184     if (ka->ka_restorer) {
185         env->regwptr[WREG_O7] = ka->ka_restorer;
186     } else {
187         uint32_t val32;
188 
189         env->regwptr[WREG_O7] = sf_addr +
190                 offsetof(struct target_signal_frame, insns) - 2 * 4;
191 
192         /* mov __NR_sigreturn, %g1 */
193         val32 = 0x821020d8;
194         __put_user(val32, &sf->insns[0]);
195 
196         /* t 0x10 */
197         val32 = 0x91d02010;
198         __put_user(val32, &sf->insns[1]);
199     }
200     unlock_user(sf, sf_addr, sizeof(struct target_signal_frame));
201     return;
202 #if 0
203 sigill_and_return:
204     force_sig(TARGET_SIGILL);
205 #endif
206 sigsegv:
207     unlock_user(sf, sf_addr, sizeof(struct target_signal_frame));
208     force_sigsegv(sig);
209 }
210 
211 void setup_rt_frame(int sig, struct target_sigaction *ka,
212                     target_siginfo_t *info,
213                     target_sigset_t *set, CPUSPARCState *env)
214 {
215     qemu_log_mask(LOG_UNIMP, "setup_rt_frame: not implemented\n");
216 }
217 
218 long do_sigreturn(CPUSPARCState *env)
219 {
220     abi_ulong sf_addr;
221     struct target_signal_frame *sf;
222     abi_ulong up_psr, pc, npc;
223     target_sigset_t set;
224     sigset_t host_set;
225     int i;
226 
227     sf_addr = env->regwptr[WREG_SP];
228     trace_user_do_sigreturn(env, sf_addr);
229     if (!lock_user_struct(VERIFY_READ, sf, sf_addr, 1)) {
230         goto segv_and_exit;
231     }
232 
233     /* 1. Make sure we are not getting garbage from the user */
234 
235     if (sf_addr & 3)
236         goto segv_and_exit;
237 
238     __get_user(pc,  &sf->info.si_regs.pc);
239     __get_user(npc, &sf->info.si_regs.npc);
240 
241     if ((pc | npc) & 3) {
242         goto segv_and_exit;
243     }
244 
245     /* 2. Restore the state */
246     __get_user(up_psr, &sf->info.si_regs.psr);
247 
248     /* User can only change condition codes and FPU enabling in %psr. */
249     env->psr = (up_psr & (PSR_ICC /* | PSR_EF */))
250             | (env->psr & ~(PSR_ICC /* | PSR_EF */));
251 
252     env->pc = pc;
253     env->npc = npc;
254     __get_user(env->y, &sf->info.si_regs.y);
255     for (i=0; i < 8; i++) {
256         __get_user(env->gregs[i], &sf->info.si_regs.u_regs[i]);
257     }
258     for (i=0; i < 8; i++) {
259         __get_user(env->regwptr[i + WREG_O0], &sf->info.si_regs.u_regs[i + 8]);
260     }
261 
262     /* FIXME: implement FPU save/restore:
263      * __get_user(fpu_save, &sf->fpu_save);
264      * if (fpu_save) {
265      *     if (restore_fpu_state(env, fpu_save)) {
266      *         goto segv_and_exit;
267      *     }
268      * }
269      */
270 
271     /* This is pretty much atomic, no amount locking would prevent
272          * the races which exist anyways.
273          */
274     __get_user(set.sig[0], &sf->info.si_mask);
275     for(i = 1; i < TARGET_NSIG_WORDS; i++) {
276         __get_user(set.sig[i], &sf->extramask[i - 1]);
277     }
278 
279     target_to_host_sigset_internal(&host_set, &set);
280     set_sigmask(&host_set);
281 
282     unlock_user_struct(sf, sf_addr, 0);
283     return -TARGET_QEMU_ESIGRETURN;
284 
285 segv_and_exit:
286     unlock_user_struct(sf, sf_addr, 0);
287     force_sig(TARGET_SIGSEGV);
288     return -TARGET_QEMU_ESIGRETURN;
289 }
290 
291 long do_rt_sigreturn(CPUSPARCState *env)
292 {
293     trace_user_do_rt_sigreturn(env, 0);
294     qemu_log_mask(LOG_UNIMP, "do_rt_sigreturn: not implemented\n");
295     return -TARGET_ENOSYS;
296 }
297 
298 #if defined(TARGET_SPARC64) && !defined(TARGET_ABI32)
299 #define SPARC_MC_TSTATE 0
300 #define SPARC_MC_PC 1
301 #define SPARC_MC_NPC 2
302 #define SPARC_MC_Y 3
303 #define SPARC_MC_G1 4
304 #define SPARC_MC_G2 5
305 #define SPARC_MC_G3 6
306 #define SPARC_MC_G4 7
307 #define SPARC_MC_G5 8
308 #define SPARC_MC_G6 9
309 #define SPARC_MC_G7 10
310 #define SPARC_MC_O0 11
311 #define SPARC_MC_O1 12
312 #define SPARC_MC_O2 13
313 #define SPARC_MC_O3 14
314 #define SPARC_MC_O4 15
315 #define SPARC_MC_O5 16
316 #define SPARC_MC_O6 17
317 #define SPARC_MC_O7 18
318 #define SPARC_MC_NGREG 19
319 
320 typedef abi_ulong target_mc_greg_t;
321 typedef target_mc_greg_t target_mc_gregset_t[SPARC_MC_NGREG];
322 
323 struct target_mc_fq {
324     abi_ulong mcfq_addr;
325     uint32_t mcfq_insn;
326 };
327 
328 /*
329  * Note the manual 16-alignment; the kernel gets this because it
330  * includes a "long double qregs[16]" in the mcpu_fregs union,
331  * which we can't do.
332  */
333 struct target_mc_fpu {
334     union {
335         uint32_t sregs[32];
336         uint64_t dregs[32];
337         //uint128_t qregs[16];
338     } mcfpu_fregs;
339     abi_ulong mcfpu_fsr;
340     abi_ulong mcfpu_fprs;
341     abi_ulong mcfpu_gsr;
342     abi_ulong mcfpu_fq;
343     unsigned char mcfpu_qcnt;
344     unsigned char mcfpu_qentsz;
345     unsigned char mcfpu_enab;
346 } __attribute__((aligned(16)));
347 typedef struct target_mc_fpu target_mc_fpu_t;
348 
349 typedef struct {
350     target_mc_gregset_t mc_gregs;
351     target_mc_greg_t mc_fp;
352     target_mc_greg_t mc_i7;
353     target_mc_fpu_t mc_fpregs;
354 } target_mcontext_t;
355 
356 struct target_ucontext {
357     abi_ulong tuc_link;
358     abi_ulong tuc_flags;
359     target_sigset_t tuc_sigmask;
360     target_mcontext_t tuc_mcontext;
361 };
362 
363 /* A V9 register window */
364 struct target_reg_window {
365     abi_ulong locals[8];
366     abi_ulong ins[8];
367 };
368 
369 /* {set, get}context() needed for 64-bit SparcLinux userland. */
370 void sparc64_set_context(CPUSPARCState *env)
371 {
372     abi_ulong ucp_addr;
373     struct target_ucontext *ucp;
374     target_mc_gregset_t *grp;
375     target_mc_fpu_t *fpup;
376     abi_ulong pc, npc, tstate;
377     unsigned int i;
378     unsigned char fenab;
379 
380     ucp_addr = env->regwptr[WREG_O0];
381     if (!lock_user_struct(VERIFY_READ, ucp, ucp_addr, 1)) {
382         goto do_sigsegv;
383     }
384     grp  = &ucp->tuc_mcontext.mc_gregs;
385     __get_user(pc, &((*grp)[SPARC_MC_PC]));
386     __get_user(npc, &((*grp)[SPARC_MC_NPC]));
387     if ((pc | npc) & 3) {
388         goto do_sigsegv;
389     }
390     if (env->regwptr[WREG_O1]) {
391         target_sigset_t target_set;
392         sigset_t set;
393 
394         if (TARGET_NSIG_WORDS == 1) {
395             __get_user(target_set.sig[0], &ucp->tuc_sigmask.sig[0]);
396         } else {
397             abi_ulong *src, *dst;
398             src = ucp->tuc_sigmask.sig;
399             dst = target_set.sig;
400             for (i = 0; i < TARGET_NSIG_WORDS; i++, dst++, src++) {
401                 __get_user(*dst, src);
402             }
403         }
404         target_to_host_sigset_internal(&set, &target_set);
405         set_sigmask(&set);
406     }
407     env->pc = pc;
408     env->npc = npc;
409     __get_user(env->y, &((*grp)[SPARC_MC_Y]));
410     __get_user(tstate, &((*grp)[SPARC_MC_TSTATE]));
411     /* Honour TSTATE_ASI, TSTATE_ICC and TSTATE_XCC only */
412     env->asi = (tstate >> 24) & 0xff;
413     cpu_put_ccr(env, (tstate >> 32) & 0xff);
414     __get_user(env->gregs[1], (&(*grp)[SPARC_MC_G1]));
415     __get_user(env->gregs[2], (&(*grp)[SPARC_MC_G2]));
416     __get_user(env->gregs[3], (&(*grp)[SPARC_MC_G3]));
417     __get_user(env->gregs[4], (&(*grp)[SPARC_MC_G4]));
418     __get_user(env->gregs[5], (&(*grp)[SPARC_MC_G5]));
419     __get_user(env->gregs[6], (&(*grp)[SPARC_MC_G6]));
420     /* Skip g7 as that's the thread register in userspace */
421 
422     /*
423      * Note that unlike the kernel, we didn't need to mess with the
424      * guest register window state to save it into a pt_regs to run
425      * the kernel. So for us the guest's O regs are still in WREG_O*
426      * (unlike the kernel which has put them in UREG_I* in a pt_regs)
427      * and the fp and i7 are still in WREG_I6 and WREG_I7 and don't
428      * need to be written back to userspace memory.
429      */
430     __get_user(env->regwptr[WREG_O0], (&(*grp)[SPARC_MC_O0]));
431     __get_user(env->regwptr[WREG_O1], (&(*grp)[SPARC_MC_O1]));
432     __get_user(env->regwptr[WREG_O2], (&(*grp)[SPARC_MC_O2]));
433     __get_user(env->regwptr[WREG_O3], (&(*grp)[SPARC_MC_O3]));
434     __get_user(env->regwptr[WREG_O4], (&(*grp)[SPARC_MC_O4]));
435     __get_user(env->regwptr[WREG_O5], (&(*grp)[SPARC_MC_O5]));
436     __get_user(env->regwptr[WREG_O6], (&(*grp)[SPARC_MC_O6]));
437     __get_user(env->regwptr[WREG_O7], (&(*grp)[SPARC_MC_O7]));
438 
439     __get_user(env->regwptr[WREG_FP], &(ucp->tuc_mcontext.mc_fp));
440     __get_user(env->regwptr[WREG_I7], &(ucp->tuc_mcontext.mc_i7));
441 
442     fpup = &ucp->tuc_mcontext.mc_fpregs;
443 
444     __get_user(fenab, &(fpup->mcfpu_enab));
445     if (fenab) {
446         abi_ulong fprs;
447 
448         /*
449          * We use the FPRS from the guest only in deciding whether
450          * to restore the upper, lower, or both banks of the FPU regs.
451          * The kernel here writes the FPU register data into the
452          * process's current_thread_info state and unconditionally
453          * clears FPRS and TSTATE_PEF: this disables the FPU so that the
454          * next FPU-disabled trap will copy the data out of
455          * current_thread_info and into the real FPU registers.
456          * QEMU doesn't need to handle lazy-FPU-state-restoring like that,
457          * so we always load the data directly into the FPU registers
458          * and leave FPRS and TSTATE_PEF alone (so the FPU stays enabled).
459          * Note that because we (and the kernel) always write zeroes for
460          * the fenab and fprs in sparc64_get_context() none of this code
461          * will execute unless the guest manually constructed or changed
462          * the context structure.
463          */
464         __get_user(fprs, &(fpup->mcfpu_fprs));
465         if (fprs & FPRS_DL) {
466             for (i = 0; i < 16; i++) {
467                 __get_user(env->fpr[i].ll, &(fpup->mcfpu_fregs.dregs[i]));
468             }
469         }
470         if (fprs & FPRS_DU) {
471             for (i = 16; i < 32; i++) {
472                 __get_user(env->fpr[i].ll, &(fpup->mcfpu_fregs.dregs[i]));
473             }
474         }
475         __get_user(env->fsr, &(fpup->mcfpu_fsr));
476         __get_user(env->gsr, &(fpup->mcfpu_gsr));
477     }
478     unlock_user_struct(ucp, ucp_addr, 0);
479     return;
480 do_sigsegv:
481     unlock_user_struct(ucp, ucp_addr, 0);
482     force_sig(TARGET_SIGSEGV);
483 }
484 
485 void sparc64_get_context(CPUSPARCState *env)
486 {
487     abi_ulong ucp_addr;
488     struct target_ucontext *ucp;
489     target_mc_gregset_t *grp;
490     target_mcontext_t *mcp;
491     int err;
492     unsigned int i;
493     target_sigset_t target_set;
494     sigset_t set;
495 
496     ucp_addr = env->regwptr[WREG_O0];
497     if (!lock_user_struct(VERIFY_WRITE, ucp, ucp_addr, 0)) {
498         goto do_sigsegv;
499     }
500 
501     memset(ucp, 0, sizeof(*ucp));
502 
503     mcp = &ucp->tuc_mcontext;
504     grp = &mcp->mc_gregs;
505 
506     /* Skip over the trap instruction, first. */
507     env->pc = env->npc;
508     env->npc += 4;
509 
510     /* If we're only reading the signal mask then do_sigprocmask()
511      * is guaranteed not to fail, which is important because we don't
512      * have any way to signal a failure or restart this operation since
513      * this is not a normal syscall.
514      */
515     err = do_sigprocmask(0, NULL, &set);
516     assert(err == 0);
517     host_to_target_sigset_internal(&target_set, &set);
518     if (TARGET_NSIG_WORDS == 1) {
519         __put_user(target_set.sig[0],
520                    (abi_ulong *)&ucp->tuc_sigmask);
521     } else {
522         abi_ulong *src, *dst;
523         src = target_set.sig;
524         dst = ucp->tuc_sigmask.sig;
525         for (i = 0; i < TARGET_NSIG_WORDS; i++, dst++, src++) {
526             __put_user(*src, dst);
527         }
528     }
529 
530     __put_user(sparc64_tstate(env), &((*grp)[SPARC_MC_TSTATE]));
531     __put_user(env->pc, &((*grp)[SPARC_MC_PC]));
532     __put_user(env->npc, &((*grp)[SPARC_MC_NPC]));
533     __put_user(env->y, &((*grp)[SPARC_MC_Y]));
534     __put_user(env->gregs[1], &((*grp)[SPARC_MC_G1]));
535     __put_user(env->gregs[2], &((*grp)[SPARC_MC_G2]));
536     __put_user(env->gregs[3], &((*grp)[SPARC_MC_G3]));
537     __put_user(env->gregs[4], &((*grp)[SPARC_MC_G4]));
538     __put_user(env->gregs[5], &((*grp)[SPARC_MC_G5]));
539     __put_user(env->gregs[6], &((*grp)[SPARC_MC_G6]));
540     __put_user(env->gregs[7], &((*grp)[SPARC_MC_G7]));
541 
542     /*
543      * Note that unlike the kernel, we didn't need to mess with the
544      * guest register window state to save it into a pt_regs to run
545      * the kernel. So for us the guest's O regs are still in WREG_O*
546      * (unlike the kernel which has put them in UREG_I* in a pt_regs)
547      * and the fp and i7 are still in WREG_I6 and WREG_I7 and don't
548      * need to be fished out of userspace memory.
549      */
550     __put_user(env->regwptr[WREG_O0], &((*grp)[SPARC_MC_O0]));
551     __put_user(env->regwptr[WREG_O1], &((*grp)[SPARC_MC_O1]));
552     __put_user(env->regwptr[WREG_O2], &((*grp)[SPARC_MC_O2]));
553     __put_user(env->regwptr[WREG_O3], &((*grp)[SPARC_MC_O3]));
554     __put_user(env->regwptr[WREG_O4], &((*grp)[SPARC_MC_O4]));
555     __put_user(env->regwptr[WREG_O5], &((*grp)[SPARC_MC_O5]));
556     __put_user(env->regwptr[WREG_O6], &((*grp)[SPARC_MC_O6]));
557     __put_user(env->regwptr[WREG_O7], &((*grp)[SPARC_MC_O7]));
558 
559     __put_user(env->regwptr[WREG_FP], &(mcp->mc_fp));
560     __put_user(env->regwptr[WREG_I7], &(mcp->mc_i7));
561 
562     /*
563      * We don't write out the FPU state. This matches the kernel's
564      * implementation (which has the code for doing this but
565      * hidden behind an "if (fenab)" where fenab is always 0).
566      */
567 
568     unlock_user_struct(ucp, ucp_addr, 1);
569     return;
570 do_sigsegv:
571     unlock_user_struct(ucp, ucp_addr, 1);
572     force_sig(TARGET_SIGSEGV);
573 }
574 #endif
575