xref: /openbmc/qemu/linux-user/alpha/signal.c (revision 744c72a8)
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_long sc_onstack;
26     abi_long sc_mask;
27     abi_long sc_pc;
28     abi_long sc_ps;
29     abi_long sc_regs[32];
30     abi_long sc_ownedfp;
31     abi_long sc_fpregs[32];
32     abi_ulong sc_fpcr;
33     abi_ulong sc_fp_control;
34     abi_ulong sc_reserved1;
35     abi_ulong sc_reserved2;
36     abi_ulong sc_ssize;
37     abi_ulong sc_sbase;
38     abi_ulong sc_traparg_a0;
39     abi_ulong sc_traparg_a1;
40     abi_ulong sc_traparg_a2;
41     abi_ulong sc_fp_trap_pc;
42     abi_ulong sc_fp_trigger_sum;
43     abi_ulong sc_fp_trigger_inst;
44 };
45 
46 struct target_ucontext {
47     abi_ulong tuc_flags;
48     abi_ulong tuc_link;
49     abi_ulong tuc_osf_sigmask;
50     target_stack_t tuc_stack;
51     struct target_sigcontext tuc_mcontext;
52     target_sigset_t tuc_sigmask;
53 };
54 
55 struct target_sigframe {
56     struct target_sigcontext sc;
57     unsigned int retcode[3];
58 };
59 
60 struct target_rt_sigframe {
61     target_siginfo_t info;
62     struct target_ucontext uc;
63     unsigned int retcode[3];
64 };
65 
66 #define INSN_MOV_R30_R16        0x47fe0410
67 #define INSN_LDI_R0             0x201f0000
68 #define INSN_CALLSYS            0x00000083
69 
70 static void setup_sigcontext(struct target_sigcontext *sc, CPUAlphaState *env,
71                              abi_ulong frame_addr, target_sigset_t *set)
72 {
73     int i;
74 
75     __put_user(on_sig_stack(frame_addr), &sc->sc_onstack);
76     __put_user(set->sig[0], &sc->sc_mask);
77     __put_user(env->pc, &sc->sc_pc);
78     __put_user(8, &sc->sc_ps);
79 
80     for (i = 0; i < 31; ++i) {
81         __put_user(env->ir[i], &sc->sc_regs[i]);
82     }
83     __put_user(0, &sc->sc_regs[31]);
84 
85     for (i = 0; i < 31; ++i) {
86         __put_user(env->fir[i], &sc->sc_fpregs[i]);
87     }
88     __put_user(0, &sc->sc_fpregs[31]);
89     __put_user(cpu_alpha_load_fpcr(env), &sc->sc_fpcr);
90 
91     __put_user(0, &sc->sc_traparg_a0); /* FIXME */
92     __put_user(0, &sc->sc_traparg_a1); /* FIXME */
93     __put_user(0, &sc->sc_traparg_a2); /* FIXME */
94 }
95 
96 static void restore_sigcontext(CPUAlphaState *env,
97                                struct target_sigcontext *sc)
98 {
99     uint64_t fpcr;
100     int i;
101 
102     __get_user(env->pc, &sc->sc_pc);
103 
104     for (i = 0; i < 31; ++i) {
105         __get_user(env->ir[i], &sc->sc_regs[i]);
106     }
107     for (i = 0; i < 31; ++i) {
108         __get_user(env->fir[i], &sc->sc_fpregs[i]);
109     }
110 
111     __get_user(fpcr, &sc->sc_fpcr);
112     cpu_alpha_store_fpcr(env, fpcr);
113 }
114 
115 static inline abi_ulong get_sigframe(struct target_sigaction *sa,
116                                      CPUAlphaState *env,
117                                      unsigned long framesize)
118 {
119     abi_ulong sp;
120 
121     sp = target_sigsp(get_sp_from_cpustate(env), sa);
122 
123     return (sp - framesize) & -32;
124 }
125 
126 void setup_frame(int sig, struct target_sigaction *ka,
127                  target_sigset_t *set, CPUAlphaState *env)
128 {
129     abi_ulong frame_addr, r26;
130     struct target_sigframe *frame;
131     int err = 0;
132 
133     frame_addr = get_sigframe(ka, env, sizeof(*frame));
134     trace_user_setup_frame(env, frame_addr);
135     if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) {
136         goto give_sigsegv;
137     }
138 
139     setup_sigcontext(&frame->sc, env, frame_addr, set);
140 
141     if (ka->ka_restorer) {
142         r26 = ka->ka_restorer;
143     } else {
144         __put_user(INSN_MOV_R30_R16, &frame->retcode[0]);
145         __put_user(INSN_LDI_R0 + TARGET_NR_sigreturn,
146                    &frame->retcode[1]);
147         __put_user(INSN_CALLSYS, &frame->retcode[2]);
148         /* imb() */
149         r26 = frame_addr + offsetof(struct target_sigframe, retcode);
150     }
151 
152     unlock_user_struct(frame, frame_addr, 1);
153 
154     if (err) {
155 give_sigsegv:
156         force_sigsegv(sig);
157         return;
158     }
159 
160     env->ir[IR_RA] = r26;
161     env->ir[IR_PV] = env->pc = ka->_sa_handler;
162     env->ir[IR_A0] = sig;
163     env->ir[IR_A1] = 0;
164     env->ir[IR_A2] = frame_addr + offsetof(struct target_sigframe, sc);
165     env->ir[IR_SP] = frame_addr;
166 }
167 
168 void setup_rt_frame(int sig, struct target_sigaction *ka,
169                     target_siginfo_t *info,
170                     target_sigset_t *set, CPUAlphaState *env)
171 {
172     abi_ulong frame_addr, r26;
173     struct target_rt_sigframe *frame;
174     int i, err = 0;
175 
176     frame_addr = get_sigframe(ka, env, sizeof(*frame));
177     trace_user_setup_rt_frame(env, frame_addr);
178     if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) {
179         goto give_sigsegv;
180     }
181 
182     tswap_siginfo(&frame->info, info);
183 
184     __put_user(0, &frame->uc.tuc_flags);
185     __put_user(0, &frame->uc.tuc_link);
186     __put_user(set->sig[0], &frame->uc.tuc_osf_sigmask);
187 
188     target_save_altstack(&frame->uc.tuc_stack, env);
189 
190     setup_sigcontext(&frame->uc.tuc_mcontext, env, frame_addr, set);
191     for (i = 0; i < TARGET_NSIG_WORDS; ++i) {
192         __put_user(set->sig[i], &frame->uc.tuc_sigmask.sig[i]);
193     }
194 
195     if (ka->ka_restorer) {
196         r26 = ka->ka_restorer;
197     } else {
198         __put_user(INSN_MOV_R30_R16, &frame->retcode[0]);
199         __put_user(INSN_LDI_R0 + TARGET_NR_rt_sigreturn,
200                    &frame->retcode[1]);
201         __put_user(INSN_CALLSYS, &frame->retcode[2]);
202         /* imb(); */
203         r26 = frame_addr + offsetof(struct target_rt_sigframe, retcode);
204     }
205 
206     if (err) {
207 give_sigsegv:
208         force_sigsegv(sig);
209         return;
210     }
211 
212     env->ir[IR_RA] = r26;
213     env->ir[IR_PV] = env->pc = ka->_sa_handler;
214     env->ir[IR_A0] = sig;
215     env->ir[IR_A1] = frame_addr + offsetof(struct target_rt_sigframe, info);
216     env->ir[IR_A2] = frame_addr + offsetof(struct target_rt_sigframe, uc);
217     env->ir[IR_SP] = frame_addr;
218 }
219 
220 long do_sigreturn(CPUAlphaState *env)
221 {
222     struct target_sigcontext *sc;
223     abi_ulong sc_addr = env->ir[IR_A0];
224     target_sigset_t target_set;
225     sigset_t set;
226 
227     if (!lock_user_struct(VERIFY_READ, sc, sc_addr, 1)) {
228         goto badframe;
229     }
230 
231     target_sigemptyset(&target_set);
232     __get_user(target_set.sig[0], &sc->sc_mask);
233 
234     target_to_host_sigset_internal(&set, &target_set);
235     set_sigmask(&set);
236 
237     restore_sigcontext(env, sc);
238     unlock_user_struct(sc, sc_addr, 0);
239     return -TARGET_QEMU_ESIGRETURN;
240 
241 badframe:
242     force_sig(TARGET_SIGSEGV);
243     return -TARGET_QEMU_ESIGRETURN;
244 }
245 
246 long do_rt_sigreturn(CPUAlphaState *env)
247 {
248     abi_ulong frame_addr = env->ir[IR_A0];
249     struct target_rt_sigframe *frame;
250     sigset_t set;
251 
252     trace_user_do_rt_sigreturn(env, frame_addr);
253     if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) {
254         goto badframe;
255     }
256     target_to_host_sigset(&set, &frame->uc.tuc_sigmask);
257     set_sigmask(&set);
258 
259     restore_sigcontext(env, &frame->uc.tuc_mcontext);
260     target_restore_altstack(&frame->uc.tuc_stack, env);
261 
262     unlock_user_struct(frame, frame_addr, 0);
263     return -TARGET_QEMU_ESIGRETURN;
264 
265 
266 badframe:
267     unlock_user_struct(frame, frame_addr, 0);
268     force_sig(TARGET_SIGSEGV);
269     return -TARGET_QEMU_ESIGRETURN;
270 }
271