xref: /openbmc/qemu/linux-user/microblaze/signal.c (revision 89854803)
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     struct target_pt_regs regs;  /* needs to be first */
27     uint32_t oldmask;
28 };
29 
30 struct target_stack_t {
31     abi_ulong ss_sp;
32     int ss_flags;
33     unsigned int ss_size;
34 };
35 
36 struct target_ucontext {
37     abi_ulong tuc_flags;
38     abi_ulong tuc_link;
39     struct target_stack_t tuc_stack;
40     struct target_sigcontext tuc_mcontext;
41     uint32_t tuc_extramask[TARGET_NSIG_WORDS - 1];
42 };
43 
44 /* Signal frames. */
45 struct target_signal_frame {
46     struct target_ucontext uc;
47     uint32_t extramask[TARGET_NSIG_WORDS - 1];
48     uint32_t tramp[2];
49 };
50 
51 struct rt_signal_frame {
52     siginfo_t info;
53     ucontext_t uc;
54     uint32_t tramp[2];
55 };
56 
57 static void setup_sigcontext(struct target_sigcontext *sc, CPUMBState *env)
58 {
59     __put_user(env->regs[0], &sc->regs.r0);
60     __put_user(env->regs[1], &sc->regs.r1);
61     __put_user(env->regs[2], &sc->regs.r2);
62     __put_user(env->regs[3], &sc->regs.r3);
63     __put_user(env->regs[4], &sc->regs.r4);
64     __put_user(env->regs[5], &sc->regs.r5);
65     __put_user(env->regs[6], &sc->regs.r6);
66     __put_user(env->regs[7], &sc->regs.r7);
67     __put_user(env->regs[8], &sc->regs.r8);
68     __put_user(env->regs[9], &sc->regs.r9);
69     __put_user(env->regs[10], &sc->regs.r10);
70     __put_user(env->regs[11], &sc->regs.r11);
71     __put_user(env->regs[12], &sc->regs.r12);
72     __put_user(env->regs[13], &sc->regs.r13);
73     __put_user(env->regs[14], &sc->regs.r14);
74     __put_user(env->regs[15], &sc->regs.r15);
75     __put_user(env->regs[16], &sc->regs.r16);
76     __put_user(env->regs[17], &sc->regs.r17);
77     __put_user(env->regs[18], &sc->regs.r18);
78     __put_user(env->regs[19], &sc->regs.r19);
79     __put_user(env->regs[20], &sc->regs.r20);
80     __put_user(env->regs[21], &sc->regs.r21);
81     __put_user(env->regs[22], &sc->regs.r22);
82     __put_user(env->regs[23], &sc->regs.r23);
83     __put_user(env->regs[24], &sc->regs.r24);
84     __put_user(env->regs[25], &sc->regs.r25);
85     __put_user(env->regs[26], &sc->regs.r26);
86     __put_user(env->regs[27], &sc->regs.r27);
87     __put_user(env->regs[28], &sc->regs.r28);
88     __put_user(env->regs[29], &sc->regs.r29);
89     __put_user(env->regs[30], &sc->regs.r30);
90     __put_user(env->regs[31], &sc->regs.r31);
91     __put_user(env->sregs[SR_PC], &sc->regs.pc);
92 }
93 
94 static void restore_sigcontext(struct target_sigcontext *sc, CPUMBState *env)
95 {
96     __get_user(env->regs[0], &sc->regs.r0);
97     __get_user(env->regs[1], &sc->regs.r1);
98     __get_user(env->regs[2], &sc->regs.r2);
99     __get_user(env->regs[3], &sc->regs.r3);
100     __get_user(env->regs[4], &sc->regs.r4);
101     __get_user(env->regs[5], &sc->regs.r5);
102     __get_user(env->regs[6], &sc->regs.r6);
103     __get_user(env->regs[7], &sc->regs.r7);
104     __get_user(env->regs[8], &sc->regs.r8);
105     __get_user(env->regs[9], &sc->regs.r9);
106     __get_user(env->regs[10], &sc->regs.r10);
107     __get_user(env->regs[11], &sc->regs.r11);
108     __get_user(env->regs[12], &sc->regs.r12);
109     __get_user(env->regs[13], &sc->regs.r13);
110     __get_user(env->regs[14], &sc->regs.r14);
111     __get_user(env->regs[15], &sc->regs.r15);
112     __get_user(env->regs[16], &sc->regs.r16);
113     __get_user(env->regs[17], &sc->regs.r17);
114     __get_user(env->regs[18], &sc->regs.r18);
115     __get_user(env->regs[19], &sc->regs.r19);
116     __get_user(env->regs[20], &sc->regs.r20);
117     __get_user(env->regs[21], &sc->regs.r21);
118     __get_user(env->regs[22], &sc->regs.r22);
119     __get_user(env->regs[23], &sc->regs.r23);
120     __get_user(env->regs[24], &sc->regs.r24);
121     __get_user(env->regs[25], &sc->regs.r25);
122     __get_user(env->regs[26], &sc->regs.r26);
123     __get_user(env->regs[27], &sc->regs.r27);
124     __get_user(env->regs[28], &sc->regs.r28);
125     __get_user(env->regs[29], &sc->regs.r29);
126     __get_user(env->regs[30], &sc->regs.r30);
127     __get_user(env->regs[31], &sc->regs.r31);
128     __get_user(env->sregs[SR_PC], &sc->regs.pc);
129 }
130 
131 static abi_ulong get_sigframe(struct target_sigaction *ka,
132                               CPUMBState *env, int frame_size)
133 {
134     abi_ulong sp = env->regs[1];
135 
136     sp = target_sigsp(sp, ka);
137 
138     return ((sp - frame_size) & -8UL);
139 }
140 
141 void setup_frame(int sig, struct target_sigaction *ka,
142                  target_sigset_t *set, CPUMBState *env)
143 {
144     struct target_signal_frame *frame;
145     abi_ulong frame_addr;
146     int i;
147 
148     frame_addr = get_sigframe(ka, env, sizeof *frame);
149     trace_user_setup_frame(env, frame_addr);
150     if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0))
151         goto badframe;
152 
153     /* Save the mask.  */
154     __put_user(set->sig[0], &frame->uc.tuc_mcontext.oldmask);
155 
156     for(i = 1; i < TARGET_NSIG_WORDS; i++) {
157         __put_user(set->sig[i], &frame->extramask[i - 1]);
158     }
159 
160     setup_sigcontext(&frame->uc.tuc_mcontext, env);
161 
162     /* Set up to return from userspace. If provided, use a stub
163        already in userspace. */
164     /* minus 8 is offset to cater for "rtsd r15,8" offset */
165     if (ka->sa_flags & TARGET_SA_RESTORER) {
166         env->regs[15] = ((unsigned long)ka->sa_restorer)-8;
167     } else {
168         uint32_t t;
169         /* Note, these encodings are _big endian_! */
170         /* addi r12, r0, __NR_sigreturn */
171         t = 0x31800000UL | TARGET_NR_sigreturn;
172         __put_user(t, frame->tramp + 0);
173         /* brki r14, 0x8 */
174         t = 0xb9cc0008UL;
175         __put_user(t, frame->tramp + 1);
176 
177         /* Return from sighandler will jump to the tramp.
178            Negative 8 offset because return is rtsd r15, 8 */
179         env->regs[15] = frame_addr + offsetof(struct target_signal_frame, tramp)
180                                    - 8;
181     }
182 
183     /* Set up registers for signal handler */
184     env->regs[1] = frame_addr;
185     /* Signal handler args: */
186     env->regs[5] = sig; /* Arg 0: signum */
187     env->regs[6] = 0;
188     /* arg 1: sigcontext */
189     env->regs[7] = frame_addr += offsetof(typeof(*frame), uc);
190 
191     /* Offset of 4 to handle microblaze rtid r14, 0 */
192     env->sregs[SR_PC] = (unsigned long)ka->_sa_handler;
193 
194     unlock_user_struct(frame, frame_addr, 1);
195     return;
196 badframe:
197     force_sigsegv(sig);
198 }
199 
200 void setup_rt_frame(int sig, struct target_sigaction *ka,
201                     target_siginfo_t *info,
202                     target_sigset_t *set, CPUMBState *env)
203 {
204     fprintf(stderr, "Microblaze setup_rt_frame: not implemented\n");
205 }
206 
207 long do_sigreturn(CPUMBState *env)
208 {
209     struct target_signal_frame *frame;
210     abi_ulong frame_addr;
211     target_sigset_t target_set;
212     sigset_t set;
213     int i;
214 
215     frame_addr = env->regs[R_SP];
216     trace_user_do_sigreturn(env, frame_addr);
217     /* Make sure the guest isn't playing games.  */
218     if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 1))
219         goto badframe;
220 
221     /* Restore blocked signals */
222     __get_user(target_set.sig[0], &frame->uc.tuc_mcontext.oldmask);
223     for(i = 1; i < TARGET_NSIG_WORDS; i++) {
224         __get_user(target_set.sig[i], &frame->extramask[i - 1]);
225     }
226     target_to_host_sigset_internal(&set, &target_set);
227     set_sigmask(&set);
228 
229     restore_sigcontext(&frame->uc.tuc_mcontext, env);
230     /* We got here through a sigreturn syscall, our path back is via an
231        rtb insn so setup r14 for that.  */
232     env->regs[14] = env->sregs[SR_PC];
233 
234     unlock_user_struct(frame, frame_addr, 0);
235     return -TARGET_QEMU_ESIGRETURN;
236 badframe:
237     force_sig(TARGET_SIGSEGV);
238     return -TARGET_QEMU_ESIGRETURN;
239 }
240 
241 long do_rt_sigreturn(CPUMBState *env)
242 {
243     trace_user_do_rt_sigreturn(env, 0);
244     fprintf(stderr, "Microblaze do_rt_sigreturn: not implemented\n");
245     return -TARGET_ENOSYS;
246 }
247