xref: /openbmc/qemu/linux-user/alpha/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_long sc_onstack;
27     abi_long sc_mask;
28     abi_long sc_pc;
29     abi_long sc_ps;
30     abi_long sc_regs[32];
31     abi_long sc_ownedfp;
32     abi_long sc_fpregs[32];
33     abi_ulong sc_fpcr;
34     abi_ulong sc_fp_control;
35     abi_ulong sc_reserved1;
36     abi_ulong sc_reserved2;
37     abi_ulong sc_ssize;
38     abi_ulong sc_sbase;
39     abi_ulong sc_traparg_a0;
40     abi_ulong sc_traparg_a1;
41     abi_ulong sc_traparg_a2;
42     abi_ulong sc_fp_trap_pc;
43     abi_ulong sc_fp_trigger_sum;
44     abi_ulong sc_fp_trigger_inst;
45 };
46 
47 struct target_ucontext {
48     abi_ulong tuc_flags;
49     abi_ulong tuc_link;
50     abi_ulong tuc_osf_sigmask;
51     target_stack_t tuc_stack;
52     struct target_sigcontext tuc_mcontext;
53     target_sigset_t tuc_sigmask;
54 };
55 
56 struct target_sigframe {
57     struct target_sigcontext sc;
58     unsigned int retcode[3];
59 };
60 
61 struct target_rt_sigframe {
62     target_siginfo_t info;
63     struct target_ucontext uc;
64     unsigned int retcode[3];
65 };
66 
67 #define INSN_MOV_R30_R16        0x47fe0410
68 #define INSN_LDI_R0             0x201f0000
69 #define INSN_CALLSYS            0x00000083
70 
71 static void setup_sigcontext(struct target_sigcontext *sc, CPUAlphaState *env,
72                              abi_ulong frame_addr, target_sigset_t *set)
73 {
74     int i;
75 
76     __put_user(on_sig_stack(frame_addr), &sc->sc_onstack);
77     __put_user(set->sig[0], &sc->sc_mask);
78     __put_user(env->pc, &sc->sc_pc);
79     __put_user(8, &sc->sc_ps);
80 
81     for (i = 0; i < 31; ++i) {
82         __put_user(env->ir[i], &sc->sc_regs[i]);
83     }
84     __put_user(0, &sc->sc_regs[31]);
85 
86     for (i = 0; i < 31; ++i) {
87         __put_user(env->fir[i], &sc->sc_fpregs[i]);
88     }
89     __put_user(0, &sc->sc_fpregs[31]);
90     __put_user(cpu_alpha_load_fpcr(env), &sc->sc_fpcr);
91 
92     __put_user(0, &sc->sc_traparg_a0); /* FIXME */
93     __put_user(0, &sc->sc_traparg_a1); /* FIXME */
94     __put_user(0, &sc->sc_traparg_a2); /* FIXME */
95 }
96 
97 static void restore_sigcontext(CPUAlphaState *env,
98                                struct target_sigcontext *sc)
99 {
100     uint64_t fpcr;
101     int i;
102 
103     __get_user(env->pc, &sc->sc_pc);
104 
105     for (i = 0; i < 31; ++i) {
106         __get_user(env->ir[i], &sc->sc_regs[i]);
107     }
108     for (i = 0; i < 31; ++i) {
109         __get_user(env->fir[i], &sc->sc_fpregs[i]);
110     }
111 
112     __get_user(fpcr, &sc->sc_fpcr);
113     cpu_alpha_store_fpcr(env, fpcr);
114 }
115 
116 static inline abi_ulong get_sigframe(struct target_sigaction *sa,
117                                      CPUAlphaState *env,
118                                      unsigned long framesize)
119 {
120     abi_ulong sp;
121 
122     sp = target_sigsp(get_sp_from_cpustate(env), sa);
123 
124     return (sp - framesize) & -32;
125 }
126 
127 void setup_frame(int sig, struct target_sigaction *ka,
128                  target_sigset_t *set, CPUAlphaState *env)
129 {
130     abi_ulong frame_addr, r26;
131     struct target_sigframe *frame;
132     int err = 0;
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     setup_sigcontext(&frame->sc, env, frame_addr, set);
141 
142     if (ka->sa_restorer) {
143         r26 = ka->sa_restorer;
144     } else {
145         __put_user(INSN_MOV_R30_R16, &frame->retcode[0]);
146         __put_user(INSN_LDI_R0 + TARGET_NR_sigreturn,
147                    &frame->retcode[1]);
148         __put_user(INSN_CALLSYS, &frame->retcode[2]);
149         /* imb() */
150         r26 = frame_addr + offsetof(struct target_sigframe, retcode);
151     }
152 
153     unlock_user_struct(frame, frame_addr, 1);
154 
155     if (err) {
156 give_sigsegv:
157         force_sigsegv(sig);
158         return;
159     }
160 
161     env->ir[IR_RA] = r26;
162     env->ir[IR_PV] = env->pc = ka->_sa_handler;
163     env->ir[IR_A0] = sig;
164     env->ir[IR_A1] = 0;
165     env->ir[IR_A2] = frame_addr + offsetof(struct target_sigframe, sc);
166     env->ir[IR_SP] = frame_addr;
167 }
168 
169 void setup_rt_frame(int sig, struct target_sigaction *ka,
170                     target_siginfo_t *info,
171                     target_sigset_t *set, CPUAlphaState *env)
172 {
173     abi_ulong frame_addr, r26;
174     struct target_rt_sigframe *frame;
175     int i, err = 0;
176 
177     frame_addr = get_sigframe(ka, env, sizeof(*frame));
178     trace_user_setup_rt_frame(env, frame_addr);
179     if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) {
180         goto give_sigsegv;
181     }
182 
183     tswap_siginfo(&frame->info, info);
184 
185     __put_user(0, &frame->uc.tuc_flags);
186     __put_user(0, &frame->uc.tuc_link);
187     __put_user(set->sig[0], &frame->uc.tuc_osf_sigmask);
188 
189     target_save_altstack(&frame->uc.tuc_stack, env);
190 
191     setup_sigcontext(&frame->uc.tuc_mcontext, env, frame_addr, set);
192     for (i = 0; i < TARGET_NSIG_WORDS; ++i) {
193         __put_user(set->sig[i], &frame->uc.tuc_sigmask.sig[i]);
194     }
195 
196     if (ka->sa_restorer) {
197         r26 = ka->sa_restorer;
198     } else {
199         __put_user(INSN_MOV_R30_R16, &frame->retcode[0]);
200         __put_user(INSN_LDI_R0 + TARGET_NR_rt_sigreturn,
201                    &frame->retcode[1]);
202         __put_user(INSN_CALLSYS, &frame->retcode[2]);
203         /* imb(); */
204         r26 = frame_addr + offsetof(struct target_sigframe, retcode);
205     }
206 
207     if (err) {
208 give_sigsegv:
209         force_sigsegv(sig);
210         return;
211     }
212 
213     env->ir[IR_RA] = r26;
214     env->ir[IR_PV] = env->pc = ka->_sa_handler;
215     env->ir[IR_A0] = sig;
216     env->ir[IR_A1] = frame_addr + offsetof(struct target_rt_sigframe, info);
217     env->ir[IR_A2] = frame_addr + offsetof(struct target_rt_sigframe, uc);
218     env->ir[IR_SP] = frame_addr;
219 }
220 
221 long do_sigreturn(CPUAlphaState *env)
222 {
223     struct target_sigcontext *sc;
224     abi_ulong sc_addr = env->ir[IR_A0];
225     target_sigset_t target_set;
226     sigset_t set;
227 
228     if (!lock_user_struct(VERIFY_READ, sc, sc_addr, 1)) {
229         goto badframe;
230     }
231 
232     target_sigemptyset(&target_set);
233     __get_user(target_set.sig[0], &sc->sc_mask);
234 
235     target_to_host_sigset_internal(&set, &target_set);
236     set_sigmask(&set);
237 
238     restore_sigcontext(env, sc);
239     unlock_user_struct(sc, sc_addr, 0);
240     return -TARGET_QEMU_ESIGRETURN;
241 
242 badframe:
243     force_sig(TARGET_SIGSEGV);
244     return -TARGET_QEMU_ESIGRETURN;
245 }
246 
247 long do_rt_sigreturn(CPUAlphaState *env)
248 {
249     abi_ulong frame_addr = env->ir[IR_A0];
250     struct target_rt_sigframe *frame;
251     sigset_t set;
252 
253     trace_user_do_rt_sigreturn(env, frame_addr);
254     if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) {
255         goto badframe;
256     }
257     target_to_host_sigset(&set, &frame->uc.tuc_sigmask);
258     set_sigmask(&set);
259 
260     restore_sigcontext(env, &frame->uc.tuc_mcontext);
261     if (do_sigaltstack(frame_addr + offsetof(struct target_rt_sigframe,
262                                              uc.tuc_stack),
263                        0, env->ir[IR_SP]) == -EFAULT) {
264         goto badframe;
265     }
266 
267     unlock_user_struct(frame, frame_addr, 0);
268     return -TARGET_QEMU_ESIGRETURN;
269 
270 
271 badframe:
272     unlock_user_struct(frame, frame_addr, 0);
273     force_sig(TARGET_SIGSEGV);
274     return -TARGET_QEMU_ESIGRETURN;
275 }
276