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 #define __NUM_GPRS 16
25 #define __NUM_FPRS 16
26 #define __NUM_ACRS 16
27
28 #define S390_SYSCALL_SIZE 2
29 #define __SIGNAL_FRAMESIZE 160 /* FIXME: 31-bit mode -> 96 */
30
31 #define _SIGCONTEXT_NSIG 64
32 #define _SIGCONTEXT_NSIG_BPW 64 /* FIXME: 31-bit mode -> 32 */
33 #define _SIGCONTEXT_NSIG_WORDS (_SIGCONTEXT_NSIG / _SIGCONTEXT_NSIG_BPW)
34 #define _SIGMASK_COPY_SIZE (sizeof(unsigned long)*_SIGCONTEXT_NSIG_WORDS)
35 #define PSW_ADDR_AMODE 0x0000000000000000UL /* 0x80000000UL for 31-bit */
36 #define S390_SYSCALL_OPCODE ((uint16_t)0x0a00)
37
38 typedef struct {
39 target_psw_t psw;
40 target_ulong gprs[__NUM_GPRS];
41 unsigned int acrs[__NUM_ACRS];
42 } target_s390_regs_common;
43
44 typedef struct {
45 unsigned int fpc;
46 double fprs[__NUM_FPRS];
47 } target_s390_fp_regs;
48
49 typedef struct {
50 target_s390_regs_common regs;
51 target_s390_fp_regs fpregs;
52 } target_sigregs;
53
54 struct target_sigcontext {
55 target_ulong oldmask[_SIGCONTEXT_NSIG_WORDS];
56 target_sigregs *sregs;
57 };
58
59 typedef struct {
60 uint8_t callee_used_stack[__SIGNAL_FRAMESIZE];
61 struct target_sigcontext sc;
62 target_sigregs sregs;
63 int signo;
64 uint8_t retcode[S390_SYSCALL_SIZE];
65 } sigframe;
66
67 struct target_ucontext {
68 target_ulong tuc_flags;
69 struct target_ucontext *tuc_link;
70 target_stack_t tuc_stack;
71 target_sigregs tuc_mcontext;
72 target_sigset_t tuc_sigmask; /* mask last for extensibility */
73 };
74
75 typedef struct {
76 uint8_t callee_used_stack[__SIGNAL_FRAMESIZE];
77 uint8_t retcode[S390_SYSCALL_SIZE];
78 struct target_siginfo info;
79 struct target_ucontext uc;
80 } rt_sigframe;
81
82 static inline abi_ulong
get_sigframe(struct target_sigaction * ka,CPUS390XState * env,size_t frame_size)83 get_sigframe(struct target_sigaction *ka, CPUS390XState *env, size_t frame_size)
84 {
85 abi_ulong sp;
86
87 /* Default to using normal stack */
88 sp = get_sp_from_cpustate(env);
89
90 /* This is the X/Open sanctioned signal stack switching. */
91 if (ka->sa_flags & TARGET_SA_ONSTACK) {
92 sp = target_sigsp(sp, ka);
93 }
94
95 /* This is the legacy signal stack switching. */
96 else if (/* FIXME !user_mode(regs) */ 0 &&
97 !(ka->sa_flags & TARGET_SA_RESTORER) &&
98 ka->sa_restorer) {
99 sp = (abi_ulong) ka->sa_restorer;
100 }
101
102 return (sp - frame_size) & -8ul;
103 }
104
save_sigregs(CPUS390XState * env,target_sigregs * sregs)105 static void save_sigregs(CPUS390XState *env, target_sigregs *sregs)
106 {
107 int i;
108 //save_access_regs(current->thread.acrs); FIXME
109
110 /* Copy a 'clean' PSW mask to the user to avoid leaking
111 information about whether PER is currently on. */
112 __put_user(env->psw.mask, &sregs->regs.psw.mask);
113 __put_user(env->psw.addr, &sregs->regs.psw.addr);
114 for (i = 0; i < 16; i++) {
115 __put_user(env->regs[i], &sregs->regs.gprs[i]);
116 }
117 for (i = 0; i < 16; i++) {
118 __put_user(env->aregs[i], &sregs->regs.acrs[i]);
119 }
120 /*
121 * We have to store the fp registers to current->thread.fp_regs
122 * to merge them with the emulated registers.
123 */
124 //save_fp_regs(¤t->thread.fp_regs); FIXME
125 for (i = 0; i < 16; i++) {
126 __put_user(get_freg(env, i)->ll, &sregs->fpregs.fprs[i]);
127 }
128 }
129
setup_frame(int sig,struct target_sigaction * ka,target_sigset_t * set,CPUS390XState * env)130 void setup_frame(int sig, struct target_sigaction *ka,
131 target_sigset_t *set, CPUS390XState *env)
132 {
133 sigframe *frame;
134 abi_ulong frame_addr;
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(set->sig[0], &frame->sc.oldmask[0]);
143
144 save_sigregs(env, &frame->sregs);
145
146 __put_user((abi_ulong)(unsigned long)&frame->sregs,
147 (abi_ulong *)&frame->sc.sregs);
148
149 /* Set up to return from userspace. If provided, use a stub
150 already in userspace. */
151 if (ka->sa_flags & TARGET_SA_RESTORER) {
152 env->regs[14] = (unsigned long)
153 ka->sa_restorer | PSW_ADDR_AMODE;
154 } else {
155 env->regs[14] = (frame_addr + offsetof(sigframe, retcode))
156 | PSW_ADDR_AMODE;
157 __put_user(S390_SYSCALL_OPCODE | TARGET_NR_sigreturn,
158 (uint16_t *)(frame->retcode));
159 }
160
161 /* Set up backchain. */
162 __put_user(env->regs[15], (abi_ulong *) frame);
163
164 /* Set up registers for signal handler */
165 env->regs[15] = frame_addr;
166 env->psw.addr = (target_ulong) ka->_sa_handler | PSW_ADDR_AMODE;
167
168 env->regs[2] = sig; //map_signal(sig);
169 env->regs[3] = frame_addr += offsetof(typeof(*frame), sc);
170
171 /* We forgot to include these in the sigcontext.
172 To avoid breaking binary compatibility, they are passed as args. */
173 env->regs[4] = 0; // FIXME: no clue... current->thread.trap_no;
174 env->regs[5] = 0; // FIXME: no clue... current->thread.prot_addr;
175
176 /* Place signal number on stack to allow backtrace from handler. */
177 __put_user(env->regs[2], &frame->signo);
178 unlock_user_struct(frame, frame_addr, 1);
179 return;
180
181 give_sigsegv:
182 force_sigsegv(sig);
183 }
184
setup_rt_frame(int sig,struct target_sigaction * ka,target_siginfo_t * info,target_sigset_t * set,CPUS390XState * env)185 void setup_rt_frame(int sig, struct target_sigaction *ka,
186 target_siginfo_t *info,
187 target_sigset_t *set, CPUS390XState *env)
188 {
189 int i;
190 rt_sigframe *frame;
191 abi_ulong frame_addr;
192
193 frame_addr = get_sigframe(ka, env, sizeof *frame);
194 trace_user_setup_rt_frame(env, frame_addr);
195 if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) {
196 goto give_sigsegv;
197 }
198
199 tswap_siginfo(&frame->info, info);
200
201 /* Create the ucontext. */
202 __put_user(0, &frame->uc.tuc_flags);
203 __put_user((abi_ulong)0, (abi_ulong *)&frame->uc.tuc_link);
204 target_save_altstack(&frame->uc.tuc_stack, env);
205 save_sigregs(env, &frame->uc.tuc_mcontext);
206 for (i = 0; i < TARGET_NSIG_WORDS; i++) {
207 __put_user((abi_ulong)set->sig[i],
208 (abi_ulong *)&frame->uc.tuc_sigmask.sig[i]);
209 }
210
211 /* Set up to return from userspace. If provided, use a stub
212 already in userspace. */
213 if (ka->sa_flags & TARGET_SA_RESTORER) {
214 env->regs[14] = (unsigned long) ka->sa_restorer | PSW_ADDR_AMODE;
215 } else {
216 env->regs[14] = (unsigned long) frame->retcode | PSW_ADDR_AMODE;
217 __put_user(S390_SYSCALL_OPCODE | TARGET_NR_rt_sigreturn,
218 (uint16_t *)(frame->retcode));
219 }
220
221 /* Set up backchain. */
222 __put_user(env->regs[15], (abi_ulong *) frame);
223
224 /* Set up registers for signal handler */
225 env->regs[15] = frame_addr;
226 env->psw.addr = (target_ulong) ka->_sa_handler | PSW_ADDR_AMODE;
227
228 env->regs[2] = sig; //map_signal(sig);
229 env->regs[3] = frame_addr + offsetof(typeof(*frame), info);
230 env->regs[4] = frame_addr + offsetof(typeof(*frame), uc);
231 return;
232
233 give_sigsegv:
234 force_sigsegv(sig);
235 }
236
237 static int
restore_sigregs(CPUS390XState * env,target_sigregs * sc)238 restore_sigregs(CPUS390XState *env, target_sigregs *sc)
239 {
240 int err = 0;
241 int i;
242
243 for (i = 0; i < 16; i++) {
244 __get_user(env->regs[i], &sc->regs.gprs[i]);
245 }
246
247 __get_user(env->psw.mask, &sc->regs.psw.mask);
248 trace_user_s390x_restore_sigregs(env, (unsigned long long)sc->regs.psw.addr,
249 (unsigned long long)env->psw.addr);
250 __get_user(env->psw.addr, &sc->regs.psw.addr);
251 /* FIXME: 31-bit -> | PSW_ADDR_AMODE */
252
253 for (i = 0; i < 16; i++) {
254 __get_user(env->aregs[i], &sc->regs.acrs[i]);
255 }
256 for (i = 0; i < 16; i++) {
257 __get_user(get_freg(env, i)->ll, &sc->fpregs.fprs[i]);
258 }
259
260 return err;
261 }
262
do_sigreturn(CPUS390XState * env)263 long do_sigreturn(CPUS390XState *env)
264 {
265 sigframe *frame;
266 abi_ulong frame_addr = env->regs[15];
267 target_sigset_t target_set;
268 sigset_t set;
269
270 trace_user_do_sigreturn(env, frame_addr);
271 if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) {
272 goto badframe;
273 }
274 __get_user(target_set.sig[0], &frame->sc.oldmask[0]);
275
276 target_to_host_sigset_internal(&set, &target_set);
277 set_sigmask(&set); /* ~_BLOCKABLE? */
278
279 if (restore_sigregs(env, &frame->sregs)) {
280 goto badframe;
281 }
282
283 unlock_user_struct(frame, frame_addr, 0);
284 return -TARGET_QEMU_ESIGRETURN;
285
286 badframe:
287 force_sig(TARGET_SIGSEGV);
288 return -TARGET_QEMU_ESIGRETURN;
289 }
290
do_rt_sigreturn(CPUS390XState * env)291 long do_rt_sigreturn(CPUS390XState *env)
292 {
293 rt_sigframe *frame;
294 abi_ulong frame_addr = env->regs[15];
295 sigset_t set;
296
297 trace_user_do_rt_sigreturn(env, frame_addr);
298 if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) {
299 goto badframe;
300 }
301 target_to_host_sigset(&set, &frame->uc.tuc_sigmask);
302
303 set_sigmask(&set); /* ~_BLOCKABLE? */
304
305 if (restore_sigregs(env, &frame->uc.tuc_mcontext)) {
306 goto badframe;
307 }
308
309 if (do_sigaltstack(frame_addr + offsetof(rt_sigframe, uc.tuc_stack), 0,
310 get_sp_from_cpustate(env)) == -EFAULT) {
311 goto badframe;
312 }
313 unlock_user_struct(frame, frame_addr, 0);
314 return -TARGET_QEMU_ESIGRETURN;
315
316 badframe:
317 unlock_user_struct(frame, frame_addr, 0);
318 force_sig(TARGET_SIGSEGV);
319 return -TARGET_QEMU_ESIGRETURN;
320 }
321