xref: /openbmc/qemu/linux-user/m68k/signal.c (revision ef17dd6a)
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 "user-internals.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     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     struct target_siginfo info;
79     struct target_ucontext uc;
80 };
81 
82 static void setup_sigcontext(struct target_sigcontext *sc, CPUM68KState *env,
83                              abi_ulong mask)
84 {
85     uint32_t sr = (env->sr & 0xff00) | cpu_m68k_get_ccr(env);
86     __put_user(mask, &sc->sc_mask);
87     __put_user(env->aregs[7], &sc->sc_usp);
88     __put_user(env->dregs[0], &sc->sc_d0);
89     __put_user(env->dregs[1], &sc->sc_d1);
90     __put_user(env->aregs[0], &sc->sc_a0);
91     __put_user(env->aregs[1], &sc->sc_a1);
92     __put_user(sr, &sc->sc_sr);
93     __put_user(env->pc, &sc->sc_pc);
94 }
95 
96 static void
97 restore_sigcontext(CPUM68KState *env, struct target_sigcontext *sc)
98 {
99     int temp;
100 
101     __get_user(env->aregs[7], &sc->sc_usp);
102     __get_user(env->dregs[0], &sc->sc_d0);
103     __get_user(env->dregs[1], &sc->sc_d1);
104     __get_user(env->aregs[0], &sc->sc_a0);
105     __get_user(env->aregs[1], &sc->sc_a1);
106     __get_user(env->pc, &sc->sc_pc);
107     __get_user(temp, &sc->sc_sr);
108     cpu_m68k_set_ccr(env, temp);
109 }
110 
111 /*
112  * Determine which stack to use..
113  */
114 static inline abi_ulong
115 get_sigframe(struct target_sigaction *ka, CPUM68KState *regs,
116              size_t frame_size)
117 {
118     abi_ulong sp;
119 
120     sp = target_sigsp(get_sp_from_cpustate(regs), ka);
121 
122 
123     return ((sp - frame_size) & -8UL);
124 }
125 
126 void setup_frame(int sig, struct target_sigaction *ka,
127                  target_sigset_t *set, CPUM68KState *env)
128 {
129     struct target_sigframe *frame;
130     abi_ulong frame_addr;
131     abi_ulong sc_addr;
132     int i;
133 
134     frame_addr = get_sigframe(ka, env, sizeof *frame);
135     trace_user_setup_frame(env, frame_addr);
136     if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) {
137         goto give_sigsegv;
138     }
139 
140     __put_user(sig, &frame->sig);
141 
142     sc_addr = frame_addr + offsetof(struct target_sigframe, sc);
143     __put_user(sc_addr, &frame->psc);
144 
145     setup_sigcontext(&frame->sc, env, set->sig[0]);
146 
147     for(i = 1; i < TARGET_NSIG_WORDS; i++) {
148         __put_user(set->sig[i], &frame->extramask[i - 1]);
149     }
150 
151     /* Set up to return from userspace.  */
152     __put_user(default_sigreturn, &frame->pretcode);
153 
154     env->aregs[7] = frame_addr;
155     env->pc = ka->_sa_handler;
156 
157     unlock_user_struct(frame, frame_addr, 1);
158     return;
159 
160 give_sigsegv:
161     force_sigsegv(sig);
162 }
163 
164 static inline void target_rt_save_fpu_state(struct target_ucontext *uc,
165                                            CPUM68KState *env)
166 {
167     int i;
168     target_fpregset_t *fpregs = &uc->tuc_mcontext.fpregs;
169 
170     __put_user(env->fpcr, &fpregs->f_fpcntl[0]);
171     __put_user(env->fpsr, &fpregs->f_fpcntl[1]);
172     /* fpiar is not emulated */
173 
174     for (i = 0; i < 8; i++) {
175         uint32_t high = env->fregs[i].d.high << 16;
176         __put_user(high, &fpregs->f_fpregs[i * 3]);
177         __put_user(env->fregs[i].d.low,
178                    (uint64_t *)&fpregs->f_fpregs[i * 3 + 1]);
179     }
180 }
181 
182 static inline int target_rt_setup_ucontext(struct target_ucontext *uc,
183                                            CPUM68KState *env)
184 {
185     target_greg_t *gregs = uc->tuc_mcontext.gregs;
186     uint32_t sr = (env->sr & 0xff00) | cpu_m68k_get_ccr(env);
187 
188     __put_user(TARGET_MCONTEXT_VERSION, &uc->tuc_mcontext.version);
189     __put_user(env->dregs[0], &gregs[0]);
190     __put_user(env->dregs[1], &gregs[1]);
191     __put_user(env->dregs[2], &gregs[2]);
192     __put_user(env->dregs[3], &gregs[3]);
193     __put_user(env->dregs[4], &gregs[4]);
194     __put_user(env->dregs[5], &gregs[5]);
195     __put_user(env->dregs[6], &gregs[6]);
196     __put_user(env->dregs[7], &gregs[7]);
197     __put_user(env->aregs[0], &gregs[8]);
198     __put_user(env->aregs[1], &gregs[9]);
199     __put_user(env->aregs[2], &gregs[10]);
200     __put_user(env->aregs[3], &gregs[11]);
201     __put_user(env->aregs[4], &gregs[12]);
202     __put_user(env->aregs[5], &gregs[13]);
203     __put_user(env->aregs[6], &gregs[14]);
204     __put_user(env->aregs[7], &gregs[15]);
205     __put_user(env->pc, &gregs[16]);
206     __put_user(sr, &gregs[17]);
207 
208     target_rt_save_fpu_state(uc, env);
209 
210     return 0;
211 }
212 
213 static inline void target_rt_restore_fpu_state(CPUM68KState *env,
214                                                struct target_ucontext *uc)
215 {
216     int i;
217     target_fpregset_t *fpregs = &uc->tuc_mcontext.fpregs;
218     uint32_t fpcr;
219 
220     __get_user(fpcr, &fpregs->f_fpcntl[0]);
221     cpu_m68k_set_fpcr(env, fpcr);
222     __get_user(env->fpsr, &fpregs->f_fpcntl[1]);
223     /* fpiar is not emulated */
224 
225     for (i = 0; i < 8; i++) {
226         uint32_t high;
227         __get_user(high, &fpregs->f_fpregs[i * 3]);
228         env->fregs[i].d.high = high >> 16;
229         __get_user(env->fregs[i].d.low,
230                    (uint64_t *)&fpregs->f_fpregs[i * 3 + 1]);
231     }
232 }
233 
234 static inline int target_rt_restore_ucontext(CPUM68KState *env,
235                                              struct target_ucontext *uc)
236 {
237     int temp;
238     target_greg_t *gregs = uc->tuc_mcontext.gregs;
239 
240     __get_user(temp, &uc->tuc_mcontext.version);
241     if (temp != TARGET_MCONTEXT_VERSION)
242         goto badframe;
243 
244     /* restore passed registers */
245     __get_user(env->dregs[0], &gregs[0]);
246     __get_user(env->dregs[1], &gregs[1]);
247     __get_user(env->dregs[2], &gregs[2]);
248     __get_user(env->dregs[3], &gregs[3]);
249     __get_user(env->dregs[4], &gregs[4]);
250     __get_user(env->dregs[5], &gregs[5]);
251     __get_user(env->dregs[6], &gregs[6]);
252     __get_user(env->dregs[7], &gregs[7]);
253     __get_user(env->aregs[0], &gregs[8]);
254     __get_user(env->aregs[1], &gregs[9]);
255     __get_user(env->aregs[2], &gregs[10]);
256     __get_user(env->aregs[3], &gregs[11]);
257     __get_user(env->aregs[4], &gregs[12]);
258     __get_user(env->aregs[5], &gregs[13]);
259     __get_user(env->aregs[6], &gregs[14]);
260     __get_user(env->aregs[7], &gregs[15]);
261     __get_user(env->pc, &gregs[16]);
262     __get_user(temp, &gregs[17]);
263     cpu_m68k_set_ccr(env, temp);
264 
265     target_rt_restore_fpu_state(env, uc);
266 
267     return 0;
268 
269 badframe:
270     return 1;
271 }
272 
273 void setup_rt_frame(int sig, struct target_sigaction *ka,
274                     target_siginfo_t *info,
275                     target_sigset_t *set, CPUM68KState *env)
276 {
277     struct target_rt_sigframe *frame;
278     abi_ulong frame_addr;
279     abi_ulong info_addr;
280     abi_ulong uc_addr;
281     int err = 0;
282     int i;
283 
284     frame_addr = get_sigframe(ka, env, sizeof *frame);
285     trace_user_setup_rt_frame(env, frame_addr);
286     if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) {
287         goto give_sigsegv;
288     }
289 
290     __put_user(sig, &frame->sig);
291 
292     info_addr = frame_addr + offsetof(struct target_rt_sigframe, info);
293     __put_user(info_addr, &frame->pinfo);
294 
295     uc_addr = frame_addr + offsetof(struct target_rt_sigframe, uc);
296     __put_user(uc_addr, &frame->puc);
297 
298     tswap_siginfo(&frame->info, info);
299 
300     /* Create the ucontext */
301 
302     __put_user(0, &frame->uc.tuc_flags);
303     __put_user(0, &frame->uc.tuc_link);
304     target_save_altstack(&frame->uc.tuc_stack, env);
305     err |= target_rt_setup_ucontext(&frame->uc, env);
306 
307     if (err)
308         goto give_sigsegv;
309 
310     for(i = 0; i < TARGET_NSIG_WORDS; i++) {
311         __put_user(set->sig[i], &frame->uc.tuc_sigmask.sig[i]);
312     }
313 
314     /* Set up to return from userspace.  */
315     __put_user(default_rt_sigreturn, &frame->pretcode);
316 
317     env->aregs[7] = frame_addr;
318     env->pc = ka->_sa_handler;
319 
320     unlock_user_struct(frame, frame_addr, 1);
321     return;
322 
323 give_sigsegv:
324     unlock_user_struct(frame, frame_addr, 1);
325     force_sigsegv(sig);
326 }
327 
328 long do_sigreturn(CPUM68KState *env)
329 {
330     struct target_sigframe *frame;
331     abi_ulong frame_addr = env->aregs[7] - 4;
332     target_sigset_t target_set;
333     sigset_t set;
334     int i;
335 
336     trace_user_do_sigreturn(env, frame_addr);
337     if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1))
338         goto badframe;
339 
340     /* set blocked signals */
341 
342     __get_user(target_set.sig[0], &frame->sc.sc_mask);
343 
344     for(i = 1; i < TARGET_NSIG_WORDS; i++) {
345         __get_user(target_set.sig[i], &frame->extramask[i - 1]);
346     }
347 
348     target_to_host_sigset_internal(&set, &target_set);
349     set_sigmask(&set);
350 
351     /* restore registers */
352 
353     restore_sigcontext(env, &frame->sc);
354 
355     unlock_user_struct(frame, frame_addr, 0);
356     return -QEMU_ESIGRETURN;
357 
358 badframe:
359     force_sig(TARGET_SIGSEGV);
360     return -QEMU_ESIGRETURN;
361 }
362 
363 long do_rt_sigreturn(CPUM68KState *env)
364 {
365     struct target_rt_sigframe *frame;
366     abi_ulong frame_addr = env->aregs[7] - 4;
367     sigset_t set;
368 
369     trace_user_do_rt_sigreturn(env, frame_addr);
370     if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1))
371         goto badframe;
372 
373     target_to_host_sigset(&set, &frame->uc.tuc_sigmask);
374     set_sigmask(&set);
375 
376     /* restore registers */
377 
378     if (target_rt_restore_ucontext(env, &frame->uc))
379         goto badframe;
380 
381     target_restore_altstack(&frame->uc.tuc_stack, env);
382 
383     unlock_user_struct(frame, frame_addr, 0);
384     return -QEMU_ESIGRETURN;
385 
386 badframe:
387     unlock_user_struct(frame, frame_addr, 0);
388     force_sig(TARGET_SIGSEGV);
389     return -QEMU_ESIGRETURN;
390 }
391 
392 void setup_sigtramp(abi_ulong sigtramp_page)
393 {
394     void *tramp = lock_user(VERIFY_WRITE, sigtramp_page, 4 + 6, 0);
395     assert(tramp != NULL);
396 
397     default_sigreturn = sigtramp_page;
398 
399     /* moveq #,d0; trap #0 */
400     __put_user(0x70004e40 + (TARGET_NR_sigreturn << 16), (uint32_t *)tramp);
401 
402     default_rt_sigreturn = sigtramp_page + 4;
403 
404     /* moveq #,d0; notb d0; trap #0 */
405     __put_user(0x70004600 + ((TARGET_NR_rt_sigreturn ^ 0xff) << 16),
406                (uint32_t *)(tramp + 4));
407     __put_user(0x4e40, (uint16_t *)(tramp + 8));
408 
409     unlock_user(tramp, sigtramp_page, 4 + 6);
410 }
411