aboutsummaryrefslogtreecommitdiff
path: root/linux-user/nios2/signal.c
blob: 9aa525e7237683a4fbf97211feb7d4e0e3cbb6d2 (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
/*
 *  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 "user-internals.h"
#include "signal-common.h"
#include "linux-user/trace.h"

#define MCONTEXT_VERSION 2

struct target_sigcontext {
    int version;
    unsigned long gregs[32];
};

struct target_ucontext {
    abi_ulong tuc_flags;
    abi_ulong 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;
};

static void rt_setup_ucontext(struct target_ucontext *uc, CPUNios2State *env)
{
    unsigned long *gregs = uc->tuc_mcontext.gregs;

    __put_user(MCONTEXT_VERSION, &uc->tuc_mcontext.version);
    __put_user(env->regs[1], &gregs[0]);
    __put_user(env->regs[2], &gregs[1]);
    __put_user(env->regs[3], &gregs[2]);
    __put_user(env->regs[4], &gregs[3]);
    __put_user(env->regs[5], &gregs[4]);
    __put_user(env->regs[6], &gregs[5]);
    __put_user(env->regs[7], &gregs[6]);
    __put_user(env->regs[8], &gregs[7]);
    __put_user(env->regs[9], &gregs[8]);
    __put_user(env->regs[10], &gregs[9]);
    __put_user(env->regs[11], &gregs[10]);
    __put_user(env->regs[12], &gregs[11]);
    __put_user(env->regs[13], &gregs[12]);
    __put_user(env->regs[14], &gregs[13]);
    __put_user(env->regs[15], &gregs[14]);
    __put_user(env->regs[16], &gregs[15]);
    __put_user(env->regs[17], &gregs[16]);
    __put_user(env->regs[18], &gregs[17]);
    __put_user(env->regs[19], &gregs[18]);
    __put_user(env->regs[20], &gregs[19]);
    __put_user(env->regs[21], &gregs[20]);
    __put_user(env->regs[22], &gregs[21]);
    __put_user(env->regs[23], &gregs[22]);
    __put_user(env->regs[R_RA], &gregs[23]);
    __put_user(env->regs[R_FP], &gregs[24]);
    __put_user(env->regs[R_GP], &gregs[25]);
    __put_user(env->regs[R_PC], &gregs[27]);
    __put_user(env->regs[R_SP], &gregs[28]);
}

static int rt_restore_ucontext(CPUNios2State *env, struct target_ucontext *uc)
{
    int temp;
    unsigned long *gregs = uc->tuc_mcontext.gregs;

    /* Always make any pending restarted system calls return -EINTR */
    /* current->restart_block.fn = do_no_restart_syscall; */

    __get_user(temp, &uc->tuc_mcontext.version);
    if (temp != MCONTEXT_VERSION) {
        return 1;
    }

    /* restore passed registers */
    __get_user(env->regs[1], &gregs[0]);
    __get_user(env->regs[2], &gregs[1]);
    __get_user(env->regs[3], &gregs[2]);
    __get_user(env->regs[4], &gregs[3]);
    __get_user(env->regs[5], &gregs[4]);
    __get_user(env->regs[6], &gregs[5]);
    __get_user(env->regs[7], &gregs[6]);
    __get_user(env->regs[8], &gregs[7]);
    __get_user(env->regs[9], &gregs[8]);
    __get_user(env->regs[10], &gregs[9]);
    __get_user(env->regs[11], &gregs[10]);
    __get_user(env->regs[12], &gregs[11]);
    __get_user(env->regs[13], &gregs[12]);
    __get_user(env->regs[14], &gregs[13]);
    __get_user(env->regs[15], &gregs[14]);
    __get_user(env->regs[16], &gregs[15]);
    __get_user(env->regs[17], &gregs[16]);
    __get_user(env->regs[18], &gregs[17]);
    __get_user(env->regs[19], &gregs[18]);
    __get_user(env->regs[20], &gregs[19]);
    __get_user(env->regs[21], &gregs[20]);
    __get_user(env->regs[22], &gregs[21]);
    __get_user(env->regs[23], &gregs[22]);
    /* gregs[23] is handled below */
    /* Verify, should this be settable */
    __get_user(env->regs[R_FP], &gregs[24]);
    /* Verify, should this be settable */
    __get_user(env->regs[R_GP], &gregs[25]);
    /* Not really necessary no user settable bits */
    __get_user(temp, &gregs[26]);
    __get_user(env->regs[R_PC], &gregs[27]);

    __get_user(env->regs[R_RA], &gregs[23]);
    __get_user(env->regs[R_SP], &gregs[28]);

    target_restore_altstack(&uc->tuc_stack, env);
    return 0;
}

static abi_ptr get_sigframe(struct target_sigaction *ka, CPUNios2State *env,
                            size_t frame_size)
{
    unsigned long usp;

    /* This is the X/Open sanctioned signal stack switching.  */
    usp = target_sigsp(get_sp_from_cpustate(env), ka);

    /* Verify, is it 32 or 64 bit aligned */
    return (usp - frame_size) & -8;
}

void setup_rt_frame(int sig, struct target_sigaction *ka,
                    target_siginfo_t *info,
                    target_sigset_t *set,
                    CPUNios2State *env)
{
    struct target_rt_sigframe *frame;
    abi_ptr frame_addr;
    int i;

    frame_addr = get_sigframe(ka, env, sizeof(*frame));
    if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) {
        force_sigsegv(sig);
        return;
    }

    tswap_siginfo(&frame->info, info);

    /* Create the ucontext.  */
    __put_user(0, &frame->uc.tuc_flags);
    __put_user(0, &frame->uc.tuc_link);
    target_save_altstack(&frame->uc.tuc_stack, env);
    rt_setup_ucontext(&frame->uc, env);
    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; jump to fixed address sigreturn
       trampoline on kuser page.  */
    env->regs[R_RA] = (unsigned long) (0x1044);

    /* Set up registers for signal handler */
    env->regs[R_SP] = frame_addr;
    env->regs[4] = sig;
    env->regs[5] = frame_addr + offsetof(struct target_rt_sigframe, info);
    env->regs[6] = frame_addr + offsetof(struct target_rt_sigframe, uc);
    env->regs[R_PC] = ka->_sa_handler;

    unlock_user_struct(frame, frame_addr, 1);
}

long do_rt_sigreturn(CPUNios2State *env)
{
    /* Verify, can we follow the stack back */
    abi_ulong frame_addr = env->regs[R_SP];
    struct target_rt_sigframe *frame;
    sigset_t set;

    if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) {
        goto badframe;
    }

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

    if (rt_restore_ucontext(env, &frame->uc)) {
        goto badframe;
    }

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

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