xref: /openbmc/qemu/linux-user/m68k/signal.c (revision 4a4ff4c5)
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     abi_ulong sp;
121 
122     sp = target_sigsp(get_sp_from_cpustate(regs), ka);
123 
124 
125     return ((sp - frame_size) & -8UL);
126 }
127 
128 void setup_frame(int sig, struct target_sigaction *ka,
129                  target_sigset_t *set, CPUM68KState *env)
130 {
131     struct target_sigframe *frame;
132     abi_ulong frame_addr;
133     abi_ulong retcode_addr;
134     abi_ulong sc_addr;
135     int i;
136 
137     frame_addr = get_sigframe(ka, env, sizeof *frame);
138     trace_user_setup_frame(env, frame_addr);
139     if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) {
140         goto give_sigsegv;
141     }
142 
143     __put_user(sig, &frame->sig);
144 
145     sc_addr = frame_addr + offsetof(struct target_sigframe, sc);
146     __put_user(sc_addr, &frame->psc);
147 
148     setup_sigcontext(&frame->sc, env, set->sig[0]);
149 
150     for(i = 1; i < TARGET_NSIG_WORDS; i++) {
151         __put_user(set->sig[i], &frame->extramask[i - 1]);
152     }
153 
154     /* Set up to return from userspace.  */
155 
156     retcode_addr = frame_addr + offsetof(struct target_sigframe, retcode);
157     __put_user(retcode_addr, &frame->pretcode);
158 
159     /* moveq #,d0; trap #0 */
160 
161     __put_user(0x70004e40 + (TARGET_NR_sigreturn << 16),
162                (uint32_t *)(frame->retcode));
163 
164     /* Set up to return from userspace */
165 
166     env->aregs[7] = frame_addr;
167     env->pc = ka->_sa_handler;
168 
169     unlock_user_struct(frame, frame_addr, 1);
170     return;
171 
172 give_sigsegv:
173     force_sigsegv(sig);
174 }
175 
176 static inline void target_rt_save_fpu_state(struct target_ucontext *uc,
177                                            CPUM68KState *env)
178 {
179     int i;
180     target_fpregset_t *fpregs = &uc->tuc_mcontext.fpregs;
181 
182     __put_user(env->fpcr, &fpregs->f_fpcntl[0]);
183     __put_user(env->fpsr, &fpregs->f_fpcntl[1]);
184     /* fpiar is not emulated */
185 
186     for (i = 0; i < 8; i++) {
187         uint32_t high = env->fregs[i].d.high << 16;
188         __put_user(high, &fpregs->f_fpregs[i * 3]);
189         __put_user(env->fregs[i].d.low,
190                    (uint64_t *)&fpregs->f_fpregs[i * 3 + 1]);
191     }
192 }
193 
194 static inline int target_rt_setup_ucontext(struct target_ucontext *uc,
195                                            CPUM68KState *env)
196 {
197     target_greg_t *gregs = uc->tuc_mcontext.gregs;
198     uint32_t sr = (env->sr & 0xff00) | cpu_m68k_get_ccr(env);
199 
200     __put_user(TARGET_MCONTEXT_VERSION, &uc->tuc_mcontext.version);
201     __put_user(env->dregs[0], &gregs[0]);
202     __put_user(env->dregs[1], &gregs[1]);
203     __put_user(env->dregs[2], &gregs[2]);
204     __put_user(env->dregs[3], &gregs[3]);
205     __put_user(env->dregs[4], &gregs[4]);
206     __put_user(env->dregs[5], &gregs[5]);
207     __put_user(env->dregs[6], &gregs[6]);
208     __put_user(env->dregs[7], &gregs[7]);
209     __put_user(env->aregs[0], &gregs[8]);
210     __put_user(env->aregs[1], &gregs[9]);
211     __put_user(env->aregs[2], &gregs[10]);
212     __put_user(env->aregs[3], &gregs[11]);
213     __put_user(env->aregs[4], &gregs[12]);
214     __put_user(env->aregs[5], &gregs[13]);
215     __put_user(env->aregs[6], &gregs[14]);
216     __put_user(env->aregs[7], &gregs[15]);
217     __put_user(env->pc, &gregs[16]);
218     __put_user(sr, &gregs[17]);
219 
220     target_rt_save_fpu_state(uc, env);
221 
222     return 0;
223 }
224 
225 static inline void target_rt_restore_fpu_state(CPUM68KState *env,
226                                                struct target_ucontext *uc)
227 {
228     int i;
229     target_fpregset_t *fpregs = &uc->tuc_mcontext.fpregs;
230     uint32_t fpcr;
231 
232     __get_user(fpcr, &fpregs->f_fpcntl[0]);
233     cpu_m68k_set_fpcr(env, fpcr);
234     __get_user(env->fpsr, &fpregs->f_fpcntl[1]);
235     /* fpiar is not emulated */
236 
237     for (i = 0; i < 8; i++) {
238         uint32_t high;
239         __get_user(high, &fpregs->f_fpregs[i * 3]);
240         env->fregs[i].d.high = high >> 16;
241         __get_user(env->fregs[i].d.low,
242                    (uint64_t *)&fpregs->f_fpregs[i * 3 + 1]);
243     }
244 }
245 
246 static inline int target_rt_restore_ucontext(CPUM68KState *env,
247                                              struct target_ucontext *uc)
248 {
249     int temp;
250     target_greg_t *gregs = uc->tuc_mcontext.gregs;
251 
252     __get_user(temp, &uc->tuc_mcontext.version);
253     if (temp != TARGET_MCONTEXT_VERSION)
254         goto badframe;
255 
256     /* restore passed registers */
257     __get_user(env->dregs[0], &gregs[0]);
258     __get_user(env->dregs[1], &gregs[1]);
259     __get_user(env->dregs[2], &gregs[2]);
260     __get_user(env->dregs[3], &gregs[3]);
261     __get_user(env->dregs[4], &gregs[4]);
262     __get_user(env->dregs[5], &gregs[5]);
263     __get_user(env->dregs[6], &gregs[6]);
264     __get_user(env->dregs[7], &gregs[7]);
265     __get_user(env->aregs[0], &gregs[8]);
266     __get_user(env->aregs[1], &gregs[9]);
267     __get_user(env->aregs[2], &gregs[10]);
268     __get_user(env->aregs[3], &gregs[11]);
269     __get_user(env->aregs[4], &gregs[12]);
270     __get_user(env->aregs[5], &gregs[13]);
271     __get_user(env->aregs[6], &gregs[14]);
272     __get_user(env->aregs[7], &gregs[15]);
273     __get_user(env->pc, &gregs[16]);
274     __get_user(temp, &gregs[17]);
275     cpu_m68k_set_ccr(env, temp);
276 
277     target_rt_restore_fpu_state(env, uc);
278 
279     return 0;
280 
281 badframe:
282     return 1;
283 }
284 
285 void setup_rt_frame(int sig, struct target_sigaction *ka,
286                     target_siginfo_t *info,
287                     target_sigset_t *set, CPUM68KState *env)
288 {
289     struct target_rt_sigframe *frame;
290     abi_ulong frame_addr;
291     abi_ulong retcode_addr;
292     abi_ulong info_addr;
293     abi_ulong uc_addr;
294     int err = 0;
295     int i;
296 
297     frame_addr = get_sigframe(ka, env, sizeof *frame);
298     trace_user_setup_rt_frame(env, frame_addr);
299     if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) {
300         goto give_sigsegv;
301     }
302 
303     __put_user(sig, &frame->sig);
304 
305     info_addr = frame_addr + offsetof(struct target_rt_sigframe, info);
306     __put_user(info_addr, &frame->pinfo);
307 
308     uc_addr = frame_addr + offsetof(struct target_rt_sigframe, uc);
309     __put_user(uc_addr, &frame->puc);
310 
311     tswap_siginfo(&frame->info, info);
312 
313     /* Create the ucontext */
314 
315     __put_user(0, &frame->uc.tuc_flags);
316     __put_user(0, &frame->uc.tuc_link);
317     target_save_altstack(&frame->uc.tuc_stack, env);
318     err |= target_rt_setup_ucontext(&frame->uc, env);
319 
320     if (err)
321         goto give_sigsegv;
322 
323     for(i = 0; i < TARGET_NSIG_WORDS; i++) {
324         __put_user(set->sig[i], &frame->uc.tuc_sigmask.sig[i]);
325     }
326 
327     /* Set up to return from userspace.  */
328 
329     retcode_addr = frame_addr + offsetof(struct target_sigframe, retcode);
330     __put_user(retcode_addr, &frame->pretcode);
331 
332     /* moveq #,d0; notb d0; trap #0 */
333 
334     __put_user(0x70004600 + ((TARGET_NR_rt_sigreturn ^ 0xff) << 16),
335                (uint32_t *)(frame->retcode + 0));
336     __put_user(0x4e40, (uint16_t *)(frame->retcode + 4));
337 
338     if (err)
339         goto give_sigsegv;
340 
341     /* Set up to return from userspace */
342 
343     env->aregs[7] = frame_addr;
344     env->pc = ka->_sa_handler;
345 
346     unlock_user_struct(frame, frame_addr, 1);
347     return;
348 
349 give_sigsegv:
350     unlock_user_struct(frame, frame_addr, 1);
351     force_sigsegv(sig);
352 }
353 
354 long do_sigreturn(CPUM68KState *env)
355 {
356     struct target_sigframe *frame;
357     abi_ulong frame_addr = env->aregs[7] - 4;
358     target_sigset_t target_set;
359     sigset_t set;
360     int i;
361 
362     trace_user_do_sigreturn(env, frame_addr);
363     if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1))
364         goto badframe;
365 
366     /* set blocked signals */
367 
368     __get_user(target_set.sig[0], &frame->sc.sc_mask);
369 
370     for(i = 1; i < TARGET_NSIG_WORDS; i++) {
371         __get_user(target_set.sig[i], &frame->extramask[i - 1]);
372     }
373 
374     target_to_host_sigset_internal(&set, &target_set);
375     set_sigmask(&set);
376 
377     /* restore registers */
378 
379     restore_sigcontext(env, &frame->sc);
380 
381     unlock_user_struct(frame, frame_addr, 0);
382     return -TARGET_QEMU_ESIGRETURN;
383 
384 badframe:
385     force_sig(TARGET_SIGSEGV);
386     return -TARGET_QEMU_ESIGRETURN;
387 }
388 
389 long do_rt_sigreturn(CPUM68KState *env)
390 {
391     struct target_rt_sigframe *frame;
392     abi_ulong frame_addr = env->aregs[7] - 4;
393     sigset_t set;
394 
395     trace_user_do_rt_sigreturn(env, frame_addr);
396     if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1))
397         goto badframe;
398 
399     target_to_host_sigset(&set, &frame->uc.tuc_sigmask);
400     set_sigmask(&set);
401 
402     /* restore registers */
403 
404     if (target_rt_restore_ucontext(env, &frame->uc))
405         goto badframe;
406 
407     if (do_sigaltstack(frame_addr +
408                        offsetof(struct target_rt_sigframe, uc.tuc_stack),
409                        0, get_sp_from_cpustate(env)) == -EFAULT)
410         goto badframe;
411 
412     unlock_user_struct(frame, frame_addr, 0);
413     return -TARGET_QEMU_ESIGRETURN;
414 
415 badframe:
416     unlock_user_struct(frame, frame_addr, 0);
417     force_sig(TARGET_SIGSEGV);
418     return -TARGET_QEMU_ESIGRETURN;
419 }
420