aboutsummaryrefslogtreecommitdiff
path: root/linux-user/sh4/signal.c
blob: cc89a48ff8bc78a62e2fc6f2498b97d303c1dc0e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
/*
 *  Emulation of Linux signals
 *
 *  Copyright (c) 2003 Fabrice Bellard
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, see <http://www.gnu.org/licenses/>.
 */
#include "qemu/osdep.h"
#include "qemu.h"
#include "signal-common.h"
#include "linux-user/trace.h"

/*
 * code and data structures from linux kernel:
 * include/asm-sh/sigcontext.h
 * arch/sh/kernel/signal.c
 */

struct target_sigcontext {
    target_ulong  oldmask;

    /* CPU registers */
    target_ulong  sc_gregs[16];
    target_ulong  sc_pc;
    target_ulong  sc_pr;
    target_ulong  sc_sr;
    target_ulong  sc_gbr;
    target_ulong  sc_mach;
    target_ulong  sc_macl;

    /* FPU registers */
    target_ulong  sc_fpregs[16];
    target_ulong  sc_xfpregs[16];
    unsigned int sc_fpscr;
    unsigned int sc_fpul;
    unsigned int sc_ownedfp;
};

struct target_sigframe
{
    struct target_sigcontext sc;
    target_ulong extramask[TARGET_NSIG_WORDS-1];
    uint16_t retcode[3];
};


struct target_ucontext {
    target_ulong tuc_flags;
    struct target_ucontext *tuc_link;
    target_stack_t tuc_stack;
    struct target_sigcontext tuc_mcontext;
    target_sigset_t tuc_sigmask;        /* mask last for extensibility */
};

struct target_rt_sigframe
{
    struct target_siginfo info;
    struct target_ucontext uc;
    uint16_t retcode[3];
};


#define MOVW(n)  (0x9300|((n)-2)) /* Move mem word at PC+n to R3 */
#define TRAP_NOARG 0xc310         /* Syscall w/no args (NR in R3) SH3/4 */

static abi_ulong get_sigframe(struct target_sigaction *ka,
                              unsigned long sp, size_t frame_size)
{
    sp = target_sigsp(sp, ka);

    return (sp - frame_size) & -8ul;
}

/* Notice when we're in the middle of a gUSA region and reset.
   Note that this will only occur for !parallel_cpus, as we will
   translate such sequences differently in a parallel context.  */
static void unwind_gusa(CPUSH4State *regs)
{
    /* If the stack pointer is sufficiently negative, and we haven't
       completed the sequence, then reset to the entry to the region.  */
    /* ??? The SH4 kernel checks for and address above 0xC0000000.
       However, the page mappings in qemu linux-user aren't as restricted
       and we wind up with the normal stack mapped above 0xF0000000.
       That said, there is no reason why the kernel should be allowing
       a gUSA region that spans 1GB.  Use a tighter check here, for what
       can actually be enabled by the immediate move.  */
    if (regs->gregs[15] >= -128u && regs->pc < regs->gregs[0]) {
        /* Reset the PC to before the gUSA region, as computed from
           R0 = region end, SP = -(region size), plus one more for the
           insn that actually initializes SP to the region size.  */
        regs->pc = regs->gregs[0] + regs->gregs[15] - 2;

        /* Reset the SP to the saved version in R1.  */
        regs->gregs[15] = regs->gregs[1];
    }
}

static void setup_sigcontext(struct target_sigcontext *sc,
                             CPUSH4State *regs, unsigned long mask)
{
    int i;

#define COPY(x)         __put_user(regs->x, &sc->sc_##x)
    COPY(gregs[0]); COPY(gregs[1]);
    COPY(gregs[2]); COPY(gregs[3]);
    COPY(gregs[4]); COPY(gregs[5]);
    COPY(gregs[6]); COPY(gregs[7]);
    COPY(gregs[8]); COPY(gregs[9]);
    COPY(gregs[10]); COPY(gregs[11]);
    COPY(gregs[12]); COPY(gregs[13]);
    COPY(gregs[14]); COPY(gregs[15]);
    COPY(gbr); COPY(mach);
    COPY(macl); COPY(pr);
    COPY(sr); COPY(pc);
#undef COPY

    for (i=0; i<16; i++) {
        __put_user(regs->fregs[i], &sc->sc_fpregs[i]);
    }
    __put_user(regs->fpscr, &sc->sc_fpscr);
    __put_user(regs->fpul, &sc->sc_fpul);

    /* non-iBCS2 extensions.. */
    __put_user(mask, &sc->oldmask);
}

static void restore_sigcontext(CPUSH4State *regs, struct target_sigcontext *sc)
{
    int i;

#define COPY(x)         __get_user(regs->x, &sc->sc_##x)
    COPY(gregs[0]); COPY(gregs[1]);
    COPY(gregs[2]); COPY(gregs[3]);
    COPY(gregs[4]); COPY(gregs[5]);
    COPY(gregs[6]); COPY(gregs[7]);
    COPY(gregs[8]); COPY(gregs[9]);
    COPY(gregs[10]); COPY(gregs[11]);
    COPY(gregs[12]); COPY(gregs[13]);
    COPY(gregs[14]); COPY(gregs[15]);
    COPY(gbr); COPY(mach);
    COPY(macl); COPY(pr);
    COPY(sr); COPY(pc);
#undef COPY

    for (i=0; i<16; i++) {
        __get_user(regs->fregs[i], &sc->sc_fpregs[i]);
    }
    __get_user(regs->fpscr, &sc->sc_fpscr);
    __get_user(regs->fpul, &sc->sc_fpul);

    regs->tra = -1;         /* disable syscall checks */
    regs->flags &= ~(DELAY_SLOT_MASK | GUSA_MASK);
}

void setup_frame(int sig, struct target_sigaction *ka,
                 target_sigset_t *set, CPUSH4State *regs)
{
    struct target_sigframe *frame;
    abi_ulong frame_addr;
    int i;

    unwind_gusa(regs);

    frame_addr = get_sigframe(ka, regs->gregs[15], sizeof(*frame));
    trace_user_setup_frame(regs, frame_addr);
    if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) {
        goto give_sigsegv;
    }

    setup_sigcontext(&frame->sc, regs, set->sig[0]);

    for (i = 0; i < TARGET_NSIG_WORDS - 1; i++) {
        __put_user(set->sig[i + 1], &frame->extramask[i]);
    }

    /* Set up to return from userspace.  If provided, use a stub
       already in userspace.  */
    if (ka->sa_flags & TARGET_SA_RESTORER) {
        regs->pr = (unsigned long) ka->sa_restorer;
    } else {
        /* Generate return code (system call to sigreturn) */
        abi_ulong retcode_addr = frame_addr +
                                 offsetof(struct target_sigframe, retcode);
        __put_user(MOVW(2), &frame->retcode[0]);
        __put_user(TRAP_NOARG, &frame->retcode[1]);
        __put_user((TARGET_NR_sigreturn), &frame->retcode[2]);
        regs->pr = (unsigned long) retcode_addr;
    }

    /* Set up registers for signal handler */
    regs->gregs[15] = frame_addr;
    regs->gregs[4] = sig; /* Arg for signal handler */
    regs->gregs[5] = 0;
    regs->gregs[6] = frame_addr += offsetof(typeof(*frame), sc);
    regs->pc = (unsigned long) ka->_sa_handler;
    regs->flags &= ~(DELAY_SLOT_MASK | GUSA_MASK);

    unlock_user_struct(frame, frame_addr, 1);
    return;

give_sigsegv:
    unlock_user_struct(frame, frame_addr, 1);
    force_sigsegv(sig);
}

void setup_rt_frame(int sig, struct target_sigaction *ka,
                    target_siginfo_t *info,
                    target_sigset_t *set, CPUSH4State *regs)
{
    struct target_rt_sigframe *frame;
    abi_ulong frame_addr;
    int i;

    unwind_gusa(regs);

    frame_addr = get_sigframe(ka, regs->gregs[15], sizeof(*frame));
    trace_user_setup_rt_frame(regs, frame_addr);
    if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) {
        goto give_sigsegv;
    }

    tswap_siginfo(&frame->info, info);

    /* Create the ucontext.  */
    __put_user(0, &frame->uc.tuc_flags);
    __put_user(0, (unsigned long *)&frame->uc.tuc_link);
    target_save_altstack(&frame->uc.tuc_stack, regs);
    setup_sigcontext(&frame->uc.tuc_mcontext,
                     regs, set->sig[0]);
    for(i = 0; i < TARGET_NSIG_WORDS; i++) {
        __put_user(set->sig[i], &frame->uc.tuc_sigmask.sig[i]);
    }

    /* Set up to return from userspace.  If provided, use a stub
       already in userspace.  */
    if (ka->sa_flags & TARGET_SA_RESTORER) {
        regs->pr = (unsigned long) ka->sa_restorer;
    } else {
        /* Generate return code (system call to sigreturn) */
        abi_ulong retcode_addr = frame_addr +
                                 offsetof(struct target_rt_sigframe, retcode);
        __put_user(MOVW(2), &frame->retcode[0]);
        __put_user(TRAP_NOARG, &frame->retcode[1]);
        __put_user((TARGET_NR_rt_sigreturn), &frame->retcode[2]);
        regs->pr = (unsigned long) retcode_addr;
    }

    /* Set up registers for signal handler */
    regs->gregs[15] = frame_addr;
    regs->gregs[4] = sig; /* Arg for signal handler */
    regs->gregs[5] = frame_addr + offsetof(typeof(*frame), info);
    regs->gregs[6] = frame_addr + offsetof(typeof(*frame), uc);
    regs->pc = (unsigned long) ka->_sa_handler;
    regs->flags &= ~(DELAY_SLOT_MASK | GUSA_MASK);

    unlock_user_struct(frame, frame_addr, 1);
    return;

give_sigsegv:
    unlock_user_struct(frame, frame_addr, 1);
    force_sigsegv(sig);
}

long do_sigreturn(CPUSH4State *regs)
{
    struct target_sigframe *frame;
    abi_ulong frame_addr;
    sigset_t blocked;
    target_sigset_t target_set;
    int i;

    frame_addr = regs->gregs[15];
    trace_user_do_sigreturn(regs, frame_addr);
    if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) {
        goto badframe;
    }

    __get_user(target_set.sig[0], &frame->sc.oldmask);
    for(i = 1; i < TARGET_NSIG_WORDS; i++) {
        __get_user(target_set.sig[i], &frame->extramask[i - 1]);
    }

    target_to_host_sigset_internal(&blocked, &target_set);
    set_sigmask(&blocked);

    restore_sigcontext(regs, &frame->sc);

    unlock_user_struct(frame, frame_addr, 0);
    return -TARGET_QEMU_ESIGRETURN;

badframe:
    unlock_user_struct(frame, frame_addr, 0);
    force_sig(TARGET_SIGSEGV);
    return -TARGET_QEMU_ESIGRETURN;
}

long do_rt_sigreturn(CPUSH4State *regs)
{
    struct target_rt_sigframe *frame;
    abi_ulong frame_addr;
    sigset_t blocked;

    frame_addr = regs->gregs[15];
    trace_user_do_rt_sigreturn(regs, frame_addr);
    if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) {
        goto badframe;
    }

    target_to_host_sigset(&blocked, &frame->uc.tuc_sigmask);
    set_sigmask(&blocked);

    restore_sigcontext(regs, &frame->uc.tuc_mcontext);

    if (do_sigaltstack(frame_addr +
                       offsetof(struct target_rt_sigframe, uc.tuc_stack),
                       0, get_sp_from_cpustate(regs)) == -EFAULT) {
        goto badframe;
    }

    unlock_user_struct(frame, frame_addr, 0);
    return -TARGET_QEMU_ESIGRETURN;

badframe:
    unlock_user_struct(frame, frame_addr, 0);
    force_sig(TARGET_SIGSEGV);
    return -TARGET_QEMU_ESIGRETURN;
}