xref: /openbmc/qemu/linux-user/m68k/signal.c (revision 09a274d8)
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 struct target_sigcontext {
25     abi_ulong  sc_mask;
26     abi_ulong  sc_usp;
27     abi_ulong  sc_d0;
28     abi_ulong  sc_d1;
29     abi_ulong  sc_a0;
30     abi_ulong  sc_a1;
31     unsigned short sc_sr;
32     abi_ulong  sc_pc;
33 };
34 
35 struct target_sigframe
36 {
37     abi_ulong pretcode;
38     int sig;
39     int code;
40     abi_ulong psc;
41     char retcode[8];
42     abi_ulong extramask[TARGET_NSIG_WORDS-1];
43     struct target_sigcontext sc;
44 };
45 
46 typedef int target_greg_t;
47 #define TARGET_NGREG 18
48 typedef target_greg_t target_gregset_t[TARGET_NGREG];
49 
50 typedef struct target_fpregset {
51     int f_fpcntl[3];
52     int f_fpregs[8*3];
53 } target_fpregset_t;
54 
55 struct target_mcontext {
56     int version;
57     target_gregset_t gregs;
58     target_fpregset_t fpregs;
59 };
60 
61 #define TARGET_MCONTEXT_VERSION 2
62 
63 struct target_ucontext {
64     abi_ulong tuc_flags;
65     abi_ulong tuc_link;
66     target_stack_t tuc_stack;
67     struct target_mcontext tuc_mcontext;
68     abi_long tuc_filler[80];
69     target_sigset_t tuc_sigmask;
70 };
71 
72 struct target_rt_sigframe
73 {
74     abi_ulong pretcode;
75     int sig;
76     abi_ulong pinfo;
77     abi_ulong puc;
78     char retcode[8];
79     struct target_siginfo info;
80     struct target_ucontext uc;
81 };
82 
83 static void setup_sigcontext(struct target_sigcontext *sc, CPUM68KState *env,
84                              abi_ulong mask)
85 {
86     uint32_t sr = (env->sr & 0xff00) | cpu_m68k_get_ccr(env);
87     __put_user(mask, &sc->sc_mask);
88     __put_user(env->aregs[7], &sc->sc_usp);
89     __put_user(env->dregs[0], &sc->sc_d0);
90     __put_user(env->dregs[1], &sc->sc_d1);
91     __put_user(env->aregs[0], &sc->sc_a0);
92     __put_user(env->aregs[1], &sc->sc_a1);
93     __put_user(sr, &sc->sc_sr);
94     __put_user(env->pc, &sc->sc_pc);
95 }
96 
97 static void
98 restore_sigcontext(CPUM68KState *env, struct target_sigcontext *sc)
99 {
100     int temp;
101 
102     __get_user(env->aregs[7], &sc->sc_usp);
103     __get_user(env->dregs[0], &sc->sc_d0);
104     __get_user(env->dregs[1], &sc->sc_d1);
105     __get_user(env->aregs[0], &sc->sc_a0);
106     __get_user(env->aregs[1], &sc->sc_a1);
107     __get_user(env->pc, &sc->sc_pc);
108     __get_user(temp, &sc->sc_sr);
109     cpu_m68k_set_ccr(env, temp);
110 }
111 
112 /*
113  * Determine which stack to use..
114  */
115 static inline abi_ulong
116 get_sigframe(struct target_sigaction *ka, CPUM68KState *regs,
117              size_t frame_size)
118 {
119     abi_ulong sp;
120 
121     sp = target_sigsp(get_sp_from_cpustate(regs), ka);
122 
123 
124     return ((sp - frame_size) & -8UL);
125 }
126 
127 void setup_frame(int sig, struct target_sigaction *ka,
128                  target_sigset_t *set, CPUM68KState *env)
129 {
130     struct target_sigframe *frame;
131     abi_ulong frame_addr;
132     abi_ulong retcode_addr;
133     abi_ulong sc_addr;
134     int i;
135 
136     frame_addr = get_sigframe(ka, env, sizeof *frame);
137     trace_user_setup_frame(env, frame_addr);
138     if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) {
139         goto give_sigsegv;
140     }
141 
142     __put_user(sig, &frame->sig);
143 
144     sc_addr = frame_addr + offsetof(struct target_sigframe, sc);
145     __put_user(sc_addr, &frame->psc);
146 
147     setup_sigcontext(&frame->sc, env, set->sig[0]);
148 
149     for(i = 1; i < TARGET_NSIG_WORDS; i++) {
150         __put_user(set->sig[i], &frame->extramask[i - 1]);
151     }
152 
153     /* Set up to return from userspace.  */
154 
155     retcode_addr = frame_addr + offsetof(struct target_sigframe, retcode);
156     __put_user(retcode_addr, &frame->pretcode);
157 
158     /* moveq #,d0; trap #0 */
159 
160     __put_user(0x70004e40 + (TARGET_NR_sigreturn << 16),
161                (uint32_t *)(frame->retcode));
162 
163     /* Set up to return from userspace */
164 
165     env->aregs[7] = frame_addr;
166     env->pc = ka->_sa_handler;
167 
168     unlock_user_struct(frame, frame_addr, 1);
169     return;
170 
171 give_sigsegv:
172     force_sigsegv(sig);
173 }
174 
175 static inline void target_rt_save_fpu_state(struct target_ucontext *uc,
176                                            CPUM68KState *env)
177 {
178     int i;
179     target_fpregset_t *fpregs = &uc->tuc_mcontext.fpregs;
180 
181     __put_user(env->fpcr, &fpregs->f_fpcntl[0]);
182     __put_user(env->fpsr, &fpregs->f_fpcntl[1]);
183     /* fpiar is not emulated */
184 
185     for (i = 0; i < 8; i++) {
186         uint32_t high = env->fregs[i].d.high << 16;
187         __put_user(high, &fpregs->f_fpregs[i * 3]);
188         __put_user(env->fregs[i].d.low,
189                    (uint64_t *)&fpregs->f_fpregs[i * 3 + 1]);
190     }
191 }
192 
193 static inline int target_rt_setup_ucontext(struct target_ucontext *uc,
194                                            CPUM68KState *env)
195 {
196     target_greg_t *gregs = uc->tuc_mcontext.gregs;
197     uint32_t sr = (env->sr & 0xff00) | cpu_m68k_get_ccr(env);
198 
199     __put_user(TARGET_MCONTEXT_VERSION, &uc->tuc_mcontext.version);
200     __put_user(env->dregs[0], &gregs[0]);
201     __put_user(env->dregs[1], &gregs[1]);
202     __put_user(env->dregs[2], &gregs[2]);
203     __put_user(env->dregs[3], &gregs[3]);
204     __put_user(env->dregs[4], &gregs[4]);
205     __put_user(env->dregs[5], &gregs[5]);
206     __put_user(env->dregs[6], &gregs[6]);
207     __put_user(env->dregs[7], &gregs[7]);
208     __put_user(env->aregs[0], &gregs[8]);
209     __put_user(env->aregs[1], &gregs[9]);
210     __put_user(env->aregs[2], &gregs[10]);
211     __put_user(env->aregs[3], &gregs[11]);
212     __put_user(env->aregs[4], &gregs[12]);
213     __put_user(env->aregs[5], &gregs[13]);
214     __put_user(env->aregs[6], &gregs[14]);
215     __put_user(env->aregs[7], &gregs[15]);
216     __put_user(env->pc, &gregs[16]);
217     __put_user(sr, &gregs[17]);
218 
219     target_rt_save_fpu_state(uc, env);
220 
221     return 0;
222 }
223 
224 static inline void target_rt_restore_fpu_state(CPUM68KState *env,
225                                                struct target_ucontext *uc)
226 {
227     int i;
228     target_fpregset_t *fpregs = &uc->tuc_mcontext.fpregs;
229     uint32_t fpcr;
230 
231     __get_user(fpcr, &fpregs->f_fpcntl[0]);
232     cpu_m68k_set_fpcr(env, fpcr);
233     __get_user(env->fpsr, &fpregs->f_fpcntl[1]);
234     /* fpiar is not emulated */
235 
236     for (i = 0; i < 8; i++) {
237         uint32_t high;
238         __get_user(high, &fpregs->f_fpregs[i * 3]);
239         env->fregs[i].d.high = high >> 16;
240         __get_user(env->fregs[i].d.low,
241                    (uint64_t *)&fpregs->f_fpregs[i * 3 + 1]);
242     }
243 }
244 
245 static inline int target_rt_restore_ucontext(CPUM68KState *env,
246                                              struct target_ucontext *uc)
247 {
248     int temp;
249     target_greg_t *gregs = uc->tuc_mcontext.gregs;
250 
251     __get_user(temp, &uc->tuc_mcontext.version);
252     if (temp != TARGET_MCONTEXT_VERSION)
253         goto badframe;
254 
255     /* restore passed registers */
256     __get_user(env->dregs[0], &gregs[0]);
257     __get_user(env->dregs[1], &gregs[1]);
258     __get_user(env->dregs[2], &gregs[2]);
259     __get_user(env->dregs[3], &gregs[3]);
260     __get_user(env->dregs[4], &gregs[4]);
261     __get_user(env->dregs[5], &gregs[5]);
262     __get_user(env->dregs[6], &gregs[6]);
263     __get_user(env->dregs[7], &gregs[7]);
264     __get_user(env->aregs[0], &gregs[8]);
265     __get_user(env->aregs[1], &gregs[9]);
266     __get_user(env->aregs[2], &gregs[10]);
267     __get_user(env->aregs[3], &gregs[11]);
268     __get_user(env->aregs[4], &gregs[12]);
269     __get_user(env->aregs[5], &gregs[13]);
270     __get_user(env->aregs[6], &gregs[14]);
271     __get_user(env->aregs[7], &gregs[15]);
272     __get_user(env->pc, &gregs[16]);
273     __get_user(temp, &gregs[17]);
274     cpu_m68k_set_ccr(env, temp);
275 
276     target_rt_restore_fpu_state(env, uc);
277 
278     return 0;
279 
280 badframe:
281     return 1;
282 }
283 
284 void setup_rt_frame(int sig, struct target_sigaction *ka,
285                     target_siginfo_t *info,
286                     target_sigset_t *set, CPUM68KState *env)
287 {
288     struct target_rt_sigframe *frame;
289     abi_ulong frame_addr;
290     abi_ulong retcode_addr;
291     abi_ulong info_addr;
292     abi_ulong uc_addr;
293     int err = 0;
294     int i;
295 
296     frame_addr = get_sigframe(ka, env, sizeof *frame);
297     trace_user_setup_rt_frame(env, frame_addr);
298     if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) {
299         goto give_sigsegv;
300     }
301 
302     __put_user(sig, &frame->sig);
303 
304     info_addr = frame_addr + offsetof(struct target_rt_sigframe, info);
305     __put_user(info_addr, &frame->pinfo);
306 
307     uc_addr = frame_addr + offsetof(struct target_rt_sigframe, uc);
308     __put_user(uc_addr, &frame->puc);
309 
310     tswap_siginfo(&frame->info, info);
311 
312     /* Create the ucontext */
313 
314     __put_user(0, &frame->uc.tuc_flags);
315     __put_user(0, &frame->uc.tuc_link);
316     target_save_altstack(&frame->uc.tuc_stack, env);
317     err |= target_rt_setup_ucontext(&frame->uc, env);
318 
319     if (err)
320         goto give_sigsegv;
321 
322     for(i = 0; i < TARGET_NSIG_WORDS; i++) {
323         __put_user(set->sig[i], &frame->uc.tuc_sigmask.sig[i]);
324     }
325 
326     /* Set up to return from userspace.  */
327 
328     retcode_addr = frame_addr + offsetof(struct target_sigframe, retcode);
329     __put_user(retcode_addr, &frame->pretcode);
330 
331     /* moveq #,d0; notb d0; trap #0 */
332 
333     __put_user(0x70004600 + ((TARGET_NR_rt_sigreturn ^ 0xff) << 16),
334                (uint32_t *)(frame->retcode + 0));
335     __put_user(0x4e40, (uint16_t *)(frame->retcode + 4));
336 
337     /* Set up to return from userspace */
338 
339     env->aregs[7] = frame_addr;
340     env->pc = ka->_sa_handler;
341 
342     unlock_user_struct(frame, frame_addr, 1);
343     return;
344 
345 give_sigsegv:
346     unlock_user_struct(frame, frame_addr, 1);
347     force_sigsegv(sig);
348 }
349 
350 long do_sigreturn(CPUM68KState *env)
351 {
352     struct target_sigframe *frame;
353     abi_ulong frame_addr = env->aregs[7] - 4;
354     target_sigset_t target_set;
355     sigset_t set;
356     int i;
357 
358     trace_user_do_sigreturn(env, frame_addr);
359     if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1))
360         goto badframe;
361 
362     /* set blocked signals */
363 
364     __get_user(target_set.sig[0], &frame->sc.sc_mask);
365 
366     for(i = 1; i < TARGET_NSIG_WORDS; i++) {
367         __get_user(target_set.sig[i], &frame->extramask[i - 1]);
368     }
369 
370     target_to_host_sigset_internal(&set, &target_set);
371     set_sigmask(&set);
372 
373     /* restore registers */
374 
375     restore_sigcontext(env, &frame->sc);
376 
377     unlock_user_struct(frame, frame_addr, 0);
378     return -TARGET_QEMU_ESIGRETURN;
379 
380 badframe:
381     force_sig(TARGET_SIGSEGV);
382     return -TARGET_QEMU_ESIGRETURN;
383 }
384 
385 long do_rt_sigreturn(CPUM68KState *env)
386 {
387     struct target_rt_sigframe *frame;
388     abi_ulong frame_addr = env->aregs[7] - 4;
389     sigset_t set;
390 
391     trace_user_do_rt_sigreturn(env, frame_addr);
392     if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1))
393         goto badframe;
394 
395     target_to_host_sigset(&set, &frame->uc.tuc_sigmask);
396     set_sigmask(&set);
397 
398     /* restore registers */
399 
400     if (target_rt_restore_ucontext(env, &frame->uc))
401         goto badframe;
402 
403     if (do_sigaltstack(frame_addr +
404                        offsetof(struct target_rt_sigframe, uc.tuc_stack),
405                        0, get_sp_from_cpustate(env)) == -EFAULT)
406         goto badframe;
407 
408     unlock_user_struct(frame, frame_addr, 0);
409     return -TARGET_QEMU_ESIGRETURN;
410 
411 badframe:
412     unlock_user_struct(frame, frame_addr, 0);
413     force_sig(TARGET_SIGSEGV);
414     return -TARGET_QEMU_ESIGRETURN;
415 }
416