xref: /openbmc/qemu/linux-user/m68k/signal.c (revision 9f172adb35123a093aec8feb74de0e126ae2138e)
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 "target_signal.h"
22 #include "signal-common.h"
23 #include "linux-user/trace.h"
24 
25 struct target_sigcontext {
26     abi_ulong  sc_mask;
27     abi_ulong  sc_usp;
28     abi_ulong  sc_d0;
29     abi_ulong  sc_d1;
30     abi_ulong  sc_a0;
31     abi_ulong  sc_a1;
32     unsigned short sc_sr;
33     abi_ulong  sc_pc;
34 };
35 
36 struct target_sigframe
37 {
38     abi_ulong pretcode;
39     int sig;
40     int code;
41     abi_ulong psc;
42     char retcode[8];
43     abi_ulong extramask[TARGET_NSIG_WORDS-1];
44     struct target_sigcontext sc;
45 };
46 
47 typedef int target_greg_t;
48 #define TARGET_NGREG 18
49 typedef target_greg_t target_gregset_t[TARGET_NGREG];
50 
51 typedef struct target_fpregset {
52     int f_fpcntl[3];
53     int f_fpregs[8*3];
54 } target_fpregset_t;
55 
56 struct target_mcontext {
57     int version;
58     target_gregset_t gregs;
59     target_fpregset_t fpregs;
60 };
61 
62 #define TARGET_MCONTEXT_VERSION 2
63 
64 struct target_ucontext {
65     abi_ulong tuc_flags;
66     abi_ulong tuc_link;
67     target_stack_t tuc_stack;
68     struct target_mcontext tuc_mcontext;
69     abi_long tuc_filler[80];
70     target_sigset_t tuc_sigmask;
71 };
72 
73 struct target_rt_sigframe
74 {
75     abi_ulong pretcode;
76     int sig;
77     abi_ulong pinfo;
78     abi_ulong puc;
79     char retcode[8];
80     struct target_siginfo info;
81     struct target_ucontext uc;
82 };
83 
84 static void setup_sigcontext(struct target_sigcontext *sc, CPUM68KState *env,
85                              abi_ulong mask)
86 {
87     uint32_t sr = (env->sr & 0xff00) | cpu_m68k_get_ccr(env);
88     __put_user(mask, &sc->sc_mask);
89     __put_user(env->aregs[7], &sc->sc_usp);
90     __put_user(env->dregs[0], &sc->sc_d0);
91     __put_user(env->dregs[1], &sc->sc_d1);
92     __put_user(env->aregs[0], &sc->sc_a0);
93     __put_user(env->aregs[1], &sc->sc_a1);
94     __put_user(sr, &sc->sc_sr);
95     __put_user(env->pc, &sc->sc_pc);
96 }
97 
98 static void
99 restore_sigcontext(CPUM68KState *env, struct target_sigcontext *sc)
100 {
101     int temp;
102 
103     __get_user(env->aregs[7], &sc->sc_usp);
104     __get_user(env->dregs[0], &sc->sc_d0);
105     __get_user(env->dregs[1], &sc->sc_d1);
106     __get_user(env->aregs[0], &sc->sc_a0);
107     __get_user(env->aregs[1], &sc->sc_a1);
108     __get_user(env->pc, &sc->sc_pc);
109     __get_user(temp, &sc->sc_sr);
110     cpu_m68k_set_ccr(env, temp);
111 }
112 
113 /*
114  * Determine which stack to use..
115  */
116 static inline abi_ulong
117 get_sigframe(struct target_sigaction *ka, CPUM68KState *regs,
118              size_t frame_size)
119 {
120     unsigned long sp;
121 
122     sp = regs->aregs[7];
123 
124     /* This is the X/Open sanctioned signal stack switching.  */
125     if ((ka->sa_flags & TARGET_SA_ONSTACK) && (sas_ss_flags (sp) == 0)) {
126         sp = target_sigaltstack_used.ss_sp + target_sigaltstack_used.ss_size;
127     }
128 
129     return ((sp - frame_size) & -8UL);
130 }
131 
132 void setup_frame(int sig, struct target_sigaction *ka,
133                  target_sigset_t *set, CPUM68KState *env)
134 {
135     struct target_sigframe *frame;
136     abi_ulong frame_addr;
137     abi_ulong retcode_addr;
138     abi_ulong sc_addr;
139     int i;
140 
141     frame_addr = get_sigframe(ka, env, sizeof *frame);
142     trace_user_setup_frame(env, frame_addr);
143     if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) {
144         goto give_sigsegv;
145     }
146 
147     __put_user(sig, &frame->sig);
148 
149     sc_addr = frame_addr + offsetof(struct target_sigframe, sc);
150     __put_user(sc_addr, &frame->psc);
151 
152     setup_sigcontext(&frame->sc, env, set->sig[0]);
153 
154     for(i = 1; i < TARGET_NSIG_WORDS; i++) {
155         __put_user(set->sig[i], &frame->extramask[i - 1]);
156     }
157 
158     /* Set up to return from userspace.  */
159 
160     retcode_addr = frame_addr + offsetof(struct target_sigframe, retcode);
161     __put_user(retcode_addr, &frame->pretcode);
162 
163     /* moveq #,d0; trap #0 */
164 
165     __put_user(0x70004e40 + (TARGET_NR_sigreturn << 16),
166                (uint32_t *)(frame->retcode));
167 
168     /* Set up to return from userspace */
169 
170     env->aregs[7] = frame_addr;
171     env->pc = ka->_sa_handler;
172 
173     unlock_user_struct(frame, frame_addr, 1);
174     return;
175 
176 give_sigsegv:
177     force_sigsegv(sig);
178 }
179 
180 static inline void target_rt_save_fpu_state(struct target_ucontext *uc,
181                                            CPUM68KState *env)
182 {
183     int i;
184     target_fpregset_t *fpregs = &uc->tuc_mcontext.fpregs;
185 
186     __put_user(env->fpcr, &fpregs->f_fpcntl[0]);
187     __put_user(env->fpsr, &fpregs->f_fpcntl[1]);
188     /* fpiar is not emulated */
189 
190     for (i = 0; i < 8; i++) {
191         uint32_t high = env->fregs[i].d.high << 16;
192         __put_user(high, &fpregs->f_fpregs[i * 3]);
193         __put_user(env->fregs[i].d.low,
194                    (uint64_t *)&fpregs->f_fpregs[i * 3 + 1]);
195     }
196 }
197 
198 static inline int target_rt_setup_ucontext(struct target_ucontext *uc,
199                                            CPUM68KState *env)
200 {
201     target_greg_t *gregs = uc->tuc_mcontext.gregs;
202     uint32_t sr = (env->sr & 0xff00) | cpu_m68k_get_ccr(env);
203 
204     __put_user(TARGET_MCONTEXT_VERSION, &uc->tuc_mcontext.version);
205     __put_user(env->dregs[0], &gregs[0]);
206     __put_user(env->dregs[1], &gregs[1]);
207     __put_user(env->dregs[2], &gregs[2]);
208     __put_user(env->dregs[3], &gregs[3]);
209     __put_user(env->dregs[4], &gregs[4]);
210     __put_user(env->dregs[5], &gregs[5]);
211     __put_user(env->dregs[6], &gregs[6]);
212     __put_user(env->dregs[7], &gregs[7]);
213     __put_user(env->aregs[0], &gregs[8]);
214     __put_user(env->aregs[1], &gregs[9]);
215     __put_user(env->aregs[2], &gregs[10]);
216     __put_user(env->aregs[3], &gregs[11]);
217     __put_user(env->aregs[4], &gregs[12]);
218     __put_user(env->aregs[5], &gregs[13]);
219     __put_user(env->aregs[6], &gregs[14]);
220     __put_user(env->aregs[7], &gregs[15]);
221     __put_user(env->pc, &gregs[16]);
222     __put_user(sr, &gregs[17]);
223 
224     target_rt_save_fpu_state(uc, env);
225 
226     return 0;
227 }
228 
229 static inline void target_rt_restore_fpu_state(CPUM68KState *env,
230                                                struct target_ucontext *uc)
231 {
232     int i;
233     target_fpregset_t *fpregs = &uc->tuc_mcontext.fpregs;
234     uint32_t fpcr;
235 
236     __get_user(fpcr, &fpregs->f_fpcntl[0]);
237     cpu_m68k_set_fpcr(env, fpcr);
238     __get_user(env->fpsr, &fpregs->f_fpcntl[1]);
239     /* fpiar is not emulated */
240 
241     for (i = 0; i < 8; i++) {
242         uint32_t high;
243         __get_user(high, &fpregs->f_fpregs[i * 3]);
244         env->fregs[i].d.high = high >> 16;
245         __get_user(env->fregs[i].d.low,
246                    (uint64_t *)&fpregs->f_fpregs[i * 3 + 1]);
247     }
248 }
249 
250 static inline int target_rt_restore_ucontext(CPUM68KState *env,
251                                              struct target_ucontext *uc)
252 {
253     int temp;
254     target_greg_t *gregs = uc->tuc_mcontext.gregs;
255 
256     __get_user(temp, &uc->tuc_mcontext.version);
257     if (temp != TARGET_MCONTEXT_VERSION)
258         goto badframe;
259 
260     /* restore passed registers */
261     __get_user(env->dregs[0], &gregs[0]);
262     __get_user(env->dregs[1], &gregs[1]);
263     __get_user(env->dregs[2], &gregs[2]);
264     __get_user(env->dregs[3], &gregs[3]);
265     __get_user(env->dregs[4], &gregs[4]);
266     __get_user(env->dregs[5], &gregs[5]);
267     __get_user(env->dregs[6], &gregs[6]);
268     __get_user(env->dregs[7], &gregs[7]);
269     __get_user(env->aregs[0], &gregs[8]);
270     __get_user(env->aregs[1], &gregs[9]);
271     __get_user(env->aregs[2], &gregs[10]);
272     __get_user(env->aregs[3], &gregs[11]);
273     __get_user(env->aregs[4], &gregs[12]);
274     __get_user(env->aregs[5], &gregs[13]);
275     __get_user(env->aregs[6], &gregs[14]);
276     __get_user(env->aregs[7], &gregs[15]);
277     __get_user(env->pc, &gregs[16]);
278     __get_user(temp, &gregs[17]);
279     cpu_m68k_set_ccr(env, temp);
280 
281     target_rt_restore_fpu_state(env, uc);
282 
283     return 0;
284 
285 badframe:
286     return 1;
287 }
288 
289 void setup_rt_frame(int sig, struct target_sigaction *ka,
290                     target_siginfo_t *info,
291                     target_sigset_t *set, CPUM68KState *env)
292 {
293     struct target_rt_sigframe *frame;
294     abi_ulong frame_addr;
295     abi_ulong retcode_addr;
296     abi_ulong info_addr;
297     abi_ulong uc_addr;
298     int err = 0;
299     int i;
300 
301     frame_addr = get_sigframe(ka, env, sizeof *frame);
302     trace_user_setup_rt_frame(env, frame_addr);
303     if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) {
304         goto give_sigsegv;
305     }
306 
307     __put_user(sig, &frame->sig);
308 
309     info_addr = frame_addr + offsetof(struct target_rt_sigframe, info);
310     __put_user(info_addr, &frame->pinfo);
311 
312     uc_addr = frame_addr + offsetof(struct target_rt_sigframe, uc);
313     __put_user(uc_addr, &frame->puc);
314 
315     tswap_siginfo(&frame->info, info);
316 
317     /* Create the ucontext */
318 
319     __put_user(0, &frame->uc.tuc_flags);
320     __put_user(0, &frame->uc.tuc_link);
321     __put_user(target_sigaltstack_used.ss_sp,
322                &frame->uc.tuc_stack.ss_sp);
323     __put_user(sas_ss_flags(env->aregs[7]),
324             &frame->uc.tuc_stack.ss_flags);
325     __put_user(target_sigaltstack_used.ss_size,
326                &frame->uc.tuc_stack.ss_size);
327     err |= target_rt_setup_ucontext(&frame->uc, env);
328 
329     if (err)
330         goto give_sigsegv;
331 
332     for(i = 0; i < TARGET_NSIG_WORDS; i++) {
333         __put_user(set->sig[i], &frame->uc.tuc_sigmask.sig[i]);
334     }
335 
336     /* Set up to return from userspace.  */
337 
338     retcode_addr = frame_addr + offsetof(struct target_sigframe, retcode);
339     __put_user(retcode_addr, &frame->pretcode);
340 
341     /* moveq #,d0; notb d0; trap #0 */
342 
343     __put_user(0x70004600 + ((TARGET_NR_rt_sigreturn ^ 0xff) << 16),
344                (uint32_t *)(frame->retcode + 0));
345     __put_user(0x4e40, (uint16_t *)(frame->retcode + 4));
346 
347     if (err)
348         goto give_sigsegv;
349 
350     /* Set up to return from userspace */
351 
352     env->aregs[7] = frame_addr;
353     env->pc = ka->_sa_handler;
354 
355     unlock_user_struct(frame, frame_addr, 1);
356     return;
357 
358 give_sigsegv:
359     unlock_user_struct(frame, frame_addr, 1);
360     force_sigsegv(sig);
361 }
362 
363 long do_sigreturn(CPUM68KState *env)
364 {
365     struct target_sigframe *frame;
366     abi_ulong frame_addr = env->aregs[7] - 4;
367     target_sigset_t target_set;
368     sigset_t set;
369     int i;
370 
371     trace_user_do_sigreturn(env, frame_addr);
372     if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1))
373         goto badframe;
374 
375     /* set blocked signals */
376 
377     __get_user(target_set.sig[0], &frame->sc.sc_mask);
378 
379     for(i = 1; i < TARGET_NSIG_WORDS; i++) {
380         __get_user(target_set.sig[i], &frame->extramask[i - 1]);
381     }
382 
383     target_to_host_sigset_internal(&set, &target_set);
384     set_sigmask(&set);
385 
386     /* restore registers */
387 
388     restore_sigcontext(env, &frame->sc);
389 
390     unlock_user_struct(frame, frame_addr, 0);
391     return -TARGET_QEMU_ESIGRETURN;
392 
393 badframe:
394     force_sig(TARGET_SIGSEGV);
395     return -TARGET_QEMU_ESIGRETURN;
396 }
397 
398 long do_rt_sigreturn(CPUM68KState *env)
399 {
400     struct target_rt_sigframe *frame;
401     abi_ulong frame_addr = env->aregs[7] - 4;
402     sigset_t set;
403 
404     trace_user_do_rt_sigreturn(env, frame_addr);
405     if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1))
406         goto badframe;
407 
408     target_to_host_sigset(&set, &frame->uc.tuc_sigmask);
409     set_sigmask(&set);
410 
411     /* restore registers */
412 
413     if (target_rt_restore_ucontext(env, &frame->uc))
414         goto badframe;
415 
416     if (do_sigaltstack(frame_addr +
417                        offsetof(struct target_rt_sigframe, uc.tuc_stack),
418                        0, get_sp_from_cpustate(env)) == -EFAULT)
419         goto badframe;
420 
421     unlock_user_struct(frame, frame_addr, 0);
422     return -TARGET_QEMU_ESIGRETURN;
423 
424 badframe:
425     unlock_user_struct(frame, frame_addr, 0);
426     force_sig(TARGET_SIGSEGV);
427     return -TARGET_QEMU_ESIGRETURN;
428 }
429