xref: /openbmc/qemu/linux-user/sparc/signal.c (revision 4f4fdec308d1b840d34056a0f100e14b317e1c44)
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 
68 static inline abi_ulong get_sigframe(struct target_sigaction *sa,
69                                      CPUSPARCState *env,
70                                      unsigned long framesize)
71 {
72     abi_ulong sp = get_sp_from_cpustate(env);
73 
74     /*
75      * If we are on the alternate signal stack and would overflow it, don't.
76      * Return an always-bogus address instead so we will die with SIGSEGV.
77          */
78     if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize))) {
79             return -1;
80     }
81 
82     /* This is the X/Open sanctioned signal stack switching.  */
83     sp = target_sigsp(sp, sa) - framesize;
84 
85     /* Always align the stack frame.  This handles two cases.  First,
86      * sigaltstack need not be mindful of platform specific stack
87      * alignment.  Second, if we took this signal because the stack
88      * is not aligned properly, we'd like to take the signal cleanly
89      * and report that.
90      */
91     sp &= ~15UL;
92 
93     return sp;
94 }
95 
96 static int
97 setup___siginfo(__siginfo_t *si, CPUSPARCState *env, abi_ulong mask)
98 {
99     int err = 0, i;
100 
101     __put_user(env->psr, &si->si_regs.psr);
102     __put_user(env->pc, &si->si_regs.pc);
103     __put_user(env->npc, &si->si_regs.npc);
104     __put_user(env->y, &si->si_regs.y);
105     for (i=0; i < 8; i++) {
106         __put_user(env->gregs[i], &si->si_regs.u_regs[i]);
107     }
108     for (i=0; i < 8; i++) {
109         __put_user(env->regwptr[WREG_O0 + i], &si->si_regs.u_regs[i + 8]);
110     }
111     __put_user(mask, &si->si_mask);
112     return err;
113 }
114 
115 #define NF_ALIGNEDSZ  (((sizeof(struct target_signal_frame) + 7) & (~7)))
116 
117 void setup_frame(int sig, struct target_sigaction *ka,
118                  target_sigset_t *set, CPUSPARCState *env)
119 {
120     abi_ulong sf_addr;
121     struct target_signal_frame *sf;
122     int sigframe_size, err, i;
123 
124     /* 1. Make sure everything is clean */
125     //synchronize_user_stack();
126 
127     sigframe_size = NF_ALIGNEDSZ;
128     sf_addr = get_sigframe(ka, env, sigframe_size);
129     trace_user_setup_frame(env, sf_addr);
130 
131     sf = lock_user(VERIFY_WRITE, sf_addr,
132                    sizeof(struct target_signal_frame), 0);
133     if (!sf) {
134         goto sigsegv;
135     }
136 #if 0
137     if (invalid_frame_pointer(sf, sigframe_size))
138         goto sigill_and_return;
139 #endif
140     /* 2. Save the current process state */
141     err = setup___siginfo(&sf->info, env, set->sig[0]);
142     __put_user(0, &sf->extra_size);
143 
144     //save_fpu_state(regs, &sf->fpu_state);
145     //__put_user(&sf->fpu_state, &sf->fpu_save);
146 
147     __put_user(set->sig[0], &sf->info.si_mask);
148     for (i = 0; i < TARGET_NSIG_WORDS - 1; i++) {
149         __put_user(set->sig[i + 1], &sf->extramask[i]);
150     }
151 
152     for (i = 0; i < 8; i++) {
153         __put_user(env->regwptr[i + WREG_L0], &sf->ss.locals[i]);
154     }
155     for (i = 0; i < 8; i++) {
156         __put_user(env->regwptr[i + WREG_I0], &sf->ss.ins[i]);
157     }
158     if (err)
159         goto sigsegv;
160 
161     /* 3. signal handler back-trampoline and parameters */
162     env->regwptr[WREG_SP] = sf_addr;
163     env->regwptr[WREG_O0] = sig;
164     env->regwptr[WREG_O1] = sf_addr +
165             offsetof(struct target_signal_frame, info);
166     env->regwptr[WREG_O2] = sf_addr +
167             offsetof(struct target_signal_frame, info);
168 
169     /* 4. signal handler */
170     env->pc = ka->_sa_handler;
171     env->npc = (env->pc + 4);
172     /* 5. return to kernel instructions */
173     if (ka->ka_restorer) {
174         env->regwptr[WREG_O7] = ka->ka_restorer;
175     } else {
176         uint32_t val32;
177 
178         env->regwptr[WREG_O7] = sf_addr +
179                 offsetof(struct target_signal_frame, insns) - 2 * 4;
180 
181         /* mov __NR_sigreturn, %g1 */
182         val32 = 0x821020d8;
183         __put_user(val32, &sf->insns[0]);
184 
185         /* t 0x10 */
186         val32 = 0x91d02010;
187         __put_user(val32, &sf->insns[1]);
188     }
189     unlock_user(sf, sf_addr, sizeof(struct target_signal_frame));
190     return;
191 #if 0
192 sigill_and_return:
193     force_sig(TARGET_SIGILL);
194 #endif
195 sigsegv:
196     unlock_user(sf, sf_addr, sizeof(struct target_signal_frame));
197     force_sigsegv(sig);
198 }
199 
200 void setup_rt_frame(int sig, struct target_sigaction *ka,
201                     target_siginfo_t *info,
202                     target_sigset_t *set, CPUSPARCState *env)
203 {
204     qemu_log_mask(LOG_UNIMP, "setup_rt_frame: not implemented\n");
205 }
206 
207 long do_sigreturn(CPUSPARCState *env)
208 {
209     abi_ulong sf_addr;
210     struct target_signal_frame *sf;
211     abi_ulong up_psr, pc, npc;
212     target_sigset_t set;
213     sigset_t host_set;
214     int i;
215 
216     sf_addr = env->regwptr[WREG_SP];
217     trace_user_do_sigreturn(env, sf_addr);
218     if (!lock_user_struct(VERIFY_READ, sf, sf_addr, 1)) {
219         goto segv_and_exit;
220     }
221 
222     /* 1. Make sure we are not getting garbage from the user */
223 
224     if (sf_addr & 3)
225         goto segv_and_exit;
226 
227     __get_user(pc,  &sf->info.si_regs.pc);
228     __get_user(npc, &sf->info.si_regs.npc);
229 
230     if ((pc | npc) & 3) {
231         goto segv_and_exit;
232     }
233 
234     /* 2. Restore the state */
235     __get_user(up_psr, &sf->info.si_regs.psr);
236 
237     /* User can only change condition codes and FPU enabling in %psr. */
238     env->psr = (up_psr & (PSR_ICC /* | PSR_EF */))
239             | (env->psr & ~(PSR_ICC /* | PSR_EF */));
240 
241     env->pc = pc;
242     env->npc = npc;
243     __get_user(env->y, &sf->info.si_regs.y);
244     for (i=0; i < 8; i++) {
245         __get_user(env->gregs[i], &sf->info.si_regs.u_regs[i]);
246     }
247     for (i=0; i < 8; i++) {
248         __get_user(env->regwptr[i + WREG_O0], &sf->info.si_regs.u_regs[i + 8]);
249     }
250 
251     /* FIXME: implement FPU save/restore:
252      * __get_user(fpu_save, &sf->fpu_save);
253      * if (fpu_save) {
254      *     if (restore_fpu_state(env, fpu_save)) {
255      *         goto segv_and_exit;
256      *     }
257      * }
258      */
259 
260     /* This is pretty much atomic, no amount locking would prevent
261          * the races which exist anyways.
262          */
263     __get_user(set.sig[0], &sf->info.si_mask);
264     for(i = 1; i < TARGET_NSIG_WORDS; i++) {
265         __get_user(set.sig[i], &sf->extramask[i - 1]);
266     }
267 
268     target_to_host_sigset_internal(&host_set, &set);
269     set_sigmask(&host_set);
270 
271     unlock_user_struct(sf, sf_addr, 0);
272     return -TARGET_QEMU_ESIGRETURN;
273 
274 segv_and_exit:
275     unlock_user_struct(sf, sf_addr, 0);
276     force_sig(TARGET_SIGSEGV);
277     return -TARGET_QEMU_ESIGRETURN;
278 }
279 
280 long do_rt_sigreturn(CPUSPARCState *env)
281 {
282     trace_user_do_rt_sigreturn(env, 0);
283     qemu_log_mask(LOG_UNIMP, "do_rt_sigreturn: not implemented\n");
284     return -TARGET_ENOSYS;
285 }
286 
287 #if defined(TARGET_SPARC64) && !defined(TARGET_ABI32)
288 #define SPARC_MC_TSTATE 0
289 #define SPARC_MC_PC 1
290 #define SPARC_MC_NPC 2
291 #define SPARC_MC_Y 3
292 #define SPARC_MC_G1 4
293 #define SPARC_MC_G2 5
294 #define SPARC_MC_G3 6
295 #define SPARC_MC_G4 7
296 #define SPARC_MC_G5 8
297 #define SPARC_MC_G6 9
298 #define SPARC_MC_G7 10
299 #define SPARC_MC_O0 11
300 #define SPARC_MC_O1 12
301 #define SPARC_MC_O2 13
302 #define SPARC_MC_O3 14
303 #define SPARC_MC_O4 15
304 #define SPARC_MC_O5 16
305 #define SPARC_MC_O6 17
306 #define SPARC_MC_O7 18
307 #define SPARC_MC_NGREG 19
308 
309 typedef abi_ulong target_mc_greg_t;
310 typedef target_mc_greg_t target_mc_gregset_t[SPARC_MC_NGREG];
311 
312 struct target_mc_fq {
313     abi_ulong mcfq_addr;
314     uint32_t mcfq_insn;
315 };
316 
317 /*
318  * Note the manual 16-alignment; the kernel gets this because it
319  * includes a "long double qregs[16]" in the mcpu_fregs union,
320  * which we can't do.
321  */
322 struct target_mc_fpu {
323     union {
324         uint32_t sregs[32];
325         uint64_t dregs[32];
326         //uint128_t qregs[16];
327     } mcfpu_fregs;
328     abi_ulong mcfpu_fsr;
329     abi_ulong mcfpu_fprs;
330     abi_ulong mcfpu_gsr;
331     abi_ulong mcfpu_fq;
332     unsigned char mcfpu_qcnt;
333     unsigned char mcfpu_qentsz;
334     unsigned char mcfpu_enab;
335 } __attribute__((aligned(16)));
336 typedef struct target_mc_fpu target_mc_fpu_t;
337 
338 typedef struct {
339     target_mc_gregset_t mc_gregs;
340     target_mc_greg_t mc_fp;
341     target_mc_greg_t mc_i7;
342     target_mc_fpu_t mc_fpregs;
343 } target_mcontext_t;
344 
345 struct target_ucontext {
346     abi_ulong tuc_link;
347     abi_ulong tuc_flags;
348     target_sigset_t tuc_sigmask;
349     target_mcontext_t tuc_mcontext;
350 };
351 
352 /* A V9 register window */
353 struct target_reg_window {
354     abi_ulong locals[8];
355     abi_ulong ins[8];
356 };
357 
358 /* {set, get}context() needed for 64-bit SparcLinux userland. */
359 void sparc64_set_context(CPUSPARCState *env)
360 {
361     abi_ulong ucp_addr;
362     struct target_ucontext *ucp;
363     target_mc_gregset_t *grp;
364     target_mc_fpu_t *fpup;
365     abi_ulong pc, npc, tstate;
366     unsigned int i;
367     unsigned char fenab;
368 
369     ucp_addr = env->regwptr[WREG_O0];
370     if (!lock_user_struct(VERIFY_READ, ucp, ucp_addr, 1)) {
371         goto do_sigsegv;
372     }
373     grp  = &ucp->tuc_mcontext.mc_gregs;
374     __get_user(pc, &((*grp)[SPARC_MC_PC]));
375     __get_user(npc, &((*grp)[SPARC_MC_NPC]));
376     if ((pc | npc) & 3) {
377         goto do_sigsegv;
378     }
379     if (env->regwptr[WREG_O1]) {
380         target_sigset_t target_set;
381         sigset_t set;
382 
383         if (TARGET_NSIG_WORDS == 1) {
384             __get_user(target_set.sig[0], &ucp->tuc_sigmask.sig[0]);
385         } else {
386             abi_ulong *src, *dst;
387             src = ucp->tuc_sigmask.sig;
388             dst = target_set.sig;
389             for (i = 0; i < TARGET_NSIG_WORDS; i++, dst++, src++) {
390                 __get_user(*dst, src);
391             }
392         }
393         target_to_host_sigset_internal(&set, &target_set);
394         set_sigmask(&set);
395     }
396     env->pc = pc;
397     env->npc = npc;
398     __get_user(env->y, &((*grp)[SPARC_MC_Y]));
399     __get_user(tstate, &((*grp)[SPARC_MC_TSTATE]));
400     /* Honour TSTATE_ASI, TSTATE_ICC and TSTATE_XCC only */
401     env->asi = (tstate >> 24) & 0xff;
402     cpu_put_ccr(env, (tstate >> 32) & 0xff);
403     __get_user(env->gregs[1], (&(*grp)[SPARC_MC_G1]));
404     __get_user(env->gregs[2], (&(*grp)[SPARC_MC_G2]));
405     __get_user(env->gregs[3], (&(*grp)[SPARC_MC_G3]));
406     __get_user(env->gregs[4], (&(*grp)[SPARC_MC_G4]));
407     __get_user(env->gregs[5], (&(*grp)[SPARC_MC_G5]));
408     __get_user(env->gregs[6], (&(*grp)[SPARC_MC_G6]));
409     /* Skip g7 as that's the thread register in userspace */
410 
411     /*
412      * Note that unlike the kernel, we didn't need to mess with the
413      * guest register window state to save it into a pt_regs to run
414      * the kernel. So for us the guest's O regs are still in WREG_O*
415      * (unlike the kernel which has put them in UREG_I* in a pt_regs)
416      * and the fp and i7 are still in WREG_I6 and WREG_I7 and don't
417      * need to be written back to userspace memory.
418      */
419     __get_user(env->regwptr[WREG_O0], (&(*grp)[SPARC_MC_O0]));
420     __get_user(env->regwptr[WREG_O1], (&(*grp)[SPARC_MC_O1]));
421     __get_user(env->regwptr[WREG_O2], (&(*grp)[SPARC_MC_O2]));
422     __get_user(env->regwptr[WREG_O3], (&(*grp)[SPARC_MC_O3]));
423     __get_user(env->regwptr[WREG_O4], (&(*grp)[SPARC_MC_O4]));
424     __get_user(env->regwptr[WREG_O5], (&(*grp)[SPARC_MC_O5]));
425     __get_user(env->regwptr[WREG_O6], (&(*grp)[SPARC_MC_O6]));
426     __get_user(env->regwptr[WREG_O7], (&(*grp)[SPARC_MC_O7]));
427 
428     __get_user(env->regwptr[WREG_FP], &(ucp->tuc_mcontext.mc_fp));
429     __get_user(env->regwptr[WREG_I7], &(ucp->tuc_mcontext.mc_i7));
430 
431     fpup = &ucp->tuc_mcontext.mc_fpregs;
432 
433     __get_user(fenab, &(fpup->mcfpu_enab));
434     if (fenab) {
435         abi_ulong fprs;
436 
437         /*
438          * We use the FPRS from the guest only in deciding whether
439          * to restore the upper, lower, or both banks of the FPU regs.
440          * The kernel here writes the FPU register data into the
441          * process's current_thread_info state and unconditionally
442          * clears FPRS and TSTATE_PEF: this disables the FPU so that the
443          * next FPU-disabled trap will copy the data out of
444          * current_thread_info and into the real FPU registers.
445          * QEMU doesn't need to handle lazy-FPU-state-restoring like that,
446          * so we always load the data directly into the FPU registers
447          * and leave FPRS and TSTATE_PEF alone (so the FPU stays enabled).
448          * Note that because we (and the kernel) always write zeroes for
449          * the fenab and fprs in sparc64_get_context() none of this code
450          * will execute unless the guest manually constructed or changed
451          * the context structure.
452          */
453         __get_user(fprs, &(fpup->mcfpu_fprs));
454         if (fprs & FPRS_DL) {
455             for (i = 0; i < 16; i++) {
456                 __get_user(env->fpr[i].ll, &(fpup->mcfpu_fregs.dregs[i]));
457             }
458         }
459         if (fprs & FPRS_DU) {
460             for (i = 16; i < 32; i++) {
461                 __get_user(env->fpr[i].ll, &(fpup->mcfpu_fregs.dregs[i]));
462             }
463         }
464         __get_user(env->fsr, &(fpup->mcfpu_fsr));
465         __get_user(env->gsr, &(fpup->mcfpu_gsr));
466     }
467     unlock_user_struct(ucp, ucp_addr, 0);
468     return;
469 do_sigsegv:
470     unlock_user_struct(ucp, ucp_addr, 0);
471     force_sig(TARGET_SIGSEGV);
472 }
473 
474 void sparc64_get_context(CPUSPARCState *env)
475 {
476     abi_ulong ucp_addr;
477     struct target_ucontext *ucp;
478     target_mc_gregset_t *grp;
479     target_mcontext_t *mcp;
480     int err;
481     unsigned int i;
482     target_sigset_t target_set;
483     sigset_t set;
484 
485     ucp_addr = env->regwptr[WREG_O0];
486     if (!lock_user_struct(VERIFY_WRITE, ucp, ucp_addr, 0)) {
487         goto do_sigsegv;
488     }
489 
490     memset(ucp, 0, sizeof(*ucp));
491 
492     mcp = &ucp->tuc_mcontext;
493     grp = &mcp->mc_gregs;
494 
495     /* Skip over the trap instruction, first. */
496     env->pc = env->npc;
497     env->npc += 4;
498 
499     /* If we're only reading the signal mask then do_sigprocmask()
500      * is guaranteed not to fail, which is important because we don't
501      * have any way to signal a failure or restart this operation since
502      * this is not a normal syscall.
503      */
504     err = do_sigprocmask(0, NULL, &set);
505     assert(err == 0);
506     host_to_target_sigset_internal(&target_set, &set);
507     if (TARGET_NSIG_WORDS == 1) {
508         __put_user(target_set.sig[0],
509                    (abi_ulong *)&ucp->tuc_sigmask);
510     } else {
511         abi_ulong *src, *dst;
512         src = target_set.sig;
513         dst = ucp->tuc_sigmask.sig;
514         for (i = 0; i < TARGET_NSIG_WORDS; i++, dst++, src++) {
515             __put_user(*src, dst);
516         }
517     }
518 
519     __put_user(sparc64_tstate(env), &((*grp)[SPARC_MC_TSTATE]));
520     __put_user(env->pc, &((*grp)[SPARC_MC_PC]));
521     __put_user(env->npc, &((*grp)[SPARC_MC_NPC]));
522     __put_user(env->y, &((*grp)[SPARC_MC_Y]));
523     __put_user(env->gregs[1], &((*grp)[SPARC_MC_G1]));
524     __put_user(env->gregs[2], &((*grp)[SPARC_MC_G2]));
525     __put_user(env->gregs[3], &((*grp)[SPARC_MC_G3]));
526     __put_user(env->gregs[4], &((*grp)[SPARC_MC_G4]));
527     __put_user(env->gregs[5], &((*grp)[SPARC_MC_G5]));
528     __put_user(env->gregs[6], &((*grp)[SPARC_MC_G6]));
529     __put_user(env->gregs[7], &((*grp)[SPARC_MC_G7]));
530 
531     /*
532      * Note that unlike the kernel, we didn't need to mess with the
533      * guest register window state to save it into a pt_regs to run
534      * the kernel. So for us the guest's O regs are still in WREG_O*
535      * (unlike the kernel which has put them in UREG_I* in a pt_regs)
536      * and the fp and i7 are still in WREG_I6 and WREG_I7 and don't
537      * need to be fished out of userspace memory.
538      */
539     __put_user(env->regwptr[WREG_O0], &((*grp)[SPARC_MC_O0]));
540     __put_user(env->regwptr[WREG_O1], &((*grp)[SPARC_MC_O1]));
541     __put_user(env->regwptr[WREG_O2], &((*grp)[SPARC_MC_O2]));
542     __put_user(env->regwptr[WREG_O3], &((*grp)[SPARC_MC_O3]));
543     __put_user(env->regwptr[WREG_O4], &((*grp)[SPARC_MC_O4]));
544     __put_user(env->regwptr[WREG_O5], &((*grp)[SPARC_MC_O5]));
545     __put_user(env->regwptr[WREG_O6], &((*grp)[SPARC_MC_O6]));
546     __put_user(env->regwptr[WREG_O7], &((*grp)[SPARC_MC_O7]));
547 
548     __put_user(env->regwptr[WREG_FP], &(mcp->mc_fp));
549     __put_user(env->regwptr[WREG_I7], &(mcp->mc_i7));
550 
551     /*
552      * We don't write out the FPU state. This matches the kernel's
553      * implementation (which has the code for doing this but
554      * hidden behind an "if (fenab)" where fenab is always 0).
555      */
556 
557     unlock_user_struct(ucp, ucp_addr, 1);
558     return;
559 do_sigsegv:
560     unlock_user_struct(ucp, ucp_addr, 1);
561     force_sig(TARGET_SIGSEGV);
562 }
563 #endif
564