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cd5b61d6 RK |
1 | /* |
2 | * Signal support for Hexagon processor | |
3 | * | |
7c6a5df4 | 4 | * Copyright (c) 2010-2012, The Linux Foundation. All rights reserved. |
cd5b61d6 RK |
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 version 2 and | |
8 | * only version 2 as published by the Free Software Foundation. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, | |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | * GNU General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License | |
16 | * along with this program; if not, write to the Free Software | |
17 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA | |
18 | * 02110-1301, USA. | |
19 | */ | |
20 | ||
21 | #include <linux/linkage.h> | |
22 | #include <linux/syscalls.h> | |
cd5b61d6 RK |
23 | #include <linux/tracehook.h> |
24 | #include <asm/registers.h> | |
25 | #include <asm/thread_info.h> | |
26 | #include <asm/unistd.h> | |
7c0f6ba6 | 27 | #include <linux/uaccess.h> |
cd5b61d6 RK |
28 | #include <asm/ucontext.h> |
29 | #include <asm/cacheflush.h> | |
30 | #include <asm/signal.h> | |
31 | #include <asm/vdso.h> | |
32 | ||
cd5b61d6 RK |
33 | struct rt_sigframe { |
34 | unsigned long tramp[2]; | |
35 | struct siginfo info; | |
36 | struct ucontext uc; | |
37 | }; | |
38 | ||
8bc77aa4 | 39 | static void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs, |
cd5b61d6 RK |
40 | size_t frame_size) |
41 | { | |
8bc77aa4 | 42 | unsigned long sp = sigsp(regs->r29, ksig); |
cd5b61d6 RK |
43 | |
44 | return (void __user *)((sp - frame_size) & ~(sizeof(long long) - 1)); | |
45 | } | |
46 | ||
47 | static int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc) | |
48 | { | |
49 | unsigned long tmp; | |
50 | int err = 0; | |
51 | ||
52 | err |= copy_to_user(&sc->sc_regs.r0, ®s->r00, | |
53 | 32*sizeof(unsigned long)); | |
54 | ||
55 | err |= __put_user(regs->sa0, &sc->sc_regs.sa0); | |
56 | err |= __put_user(regs->lc0, &sc->sc_regs.lc0); | |
57 | err |= __put_user(regs->sa1, &sc->sc_regs.sa1); | |
58 | err |= __put_user(regs->lc1, &sc->sc_regs.lc1); | |
59 | err |= __put_user(regs->m0, &sc->sc_regs.m0); | |
60 | err |= __put_user(regs->m1, &sc->sc_regs.m1); | |
61 | err |= __put_user(regs->usr, &sc->sc_regs.usr); | |
62 | err |= __put_user(regs->preds, &sc->sc_regs.p3_0); | |
63 | err |= __put_user(regs->gp, &sc->sc_regs.gp); | |
64 | err |= __put_user(regs->ugp, &sc->sc_regs.ugp); | |
60c4ba99 RK |
65 | #if CONFIG_HEXAGON_ARCH_VERSION >= 4 |
66 | err |= __put_user(regs->cs0, &sc->sc_regs.cs0); | |
67 | err |= __put_user(regs->cs1, &sc->sc_regs.cs1); | |
68 | #endif | |
cd5b61d6 RK |
69 | tmp = pt_elr(regs); err |= __put_user(tmp, &sc->sc_regs.pc); |
70 | tmp = pt_cause(regs); err |= __put_user(tmp, &sc->sc_regs.cause); | |
71 | tmp = pt_badva(regs); err |= __put_user(tmp, &sc->sc_regs.badva); | |
72 | ||
73 | return err; | |
74 | } | |
75 | ||
76 | static int restore_sigcontext(struct pt_regs *regs, | |
77 | struct sigcontext __user *sc) | |
78 | { | |
79 | unsigned long tmp; | |
80 | int err = 0; | |
81 | ||
82 | err |= copy_from_user(®s->r00, &sc->sc_regs.r0, | |
83 | 32 * sizeof(unsigned long)); | |
84 | ||
85 | err |= __get_user(regs->sa0, &sc->sc_regs.sa0); | |
86 | err |= __get_user(regs->lc0, &sc->sc_regs.lc0); | |
87 | err |= __get_user(regs->sa1, &sc->sc_regs.sa1); | |
88 | err |= __get_user(regs->lc1, &sc->sc_regs.lc1); | |
89 | err |= __get_user(regs->m0, &sc->sc_regs.m0); | |
90 | err |= __get_user(regs->m1, &sc->sc_regs.m1); | |
91 | err |= __get_user(regs->usr, &sc->sc_regs.usr); | |
92 | err |= __get_user(regs->preds, &sc->sc_regs.p3_0); | |
93 | err |= __get_user(regs->gp, &sc->sc_regs.gp); | |
94 | err |= __get_user(regs->ugp, &sc->sc_regs.ugp); | |
60c4ba99 RK |
95 | #if CONFIG_HEXAGON_ARCH_VERSION >= 4 |
96 | err |= __get_user(regs->cs0, &sc->sc_regs.cs0); | |
97 | err |= __get_user(regs->cs1, &sc->sc_regs.cs1); | |
98 | #endif | |
cd5b61d6 RK |
99 | err |= __get_user(tmp, &sc->sc_regs.pc); pt_set_elr(regs, tmp); |
100 | ||
101 | return err; | |
102 | } | |
103 | ||
104 | /* | |
105 | * Setup signal stack frame with siginfo structure | |
106 | */ | |
ac443624 RW |
107 | static int setup_rt_frame(struct ksignal *ksig, sigset_t *set, |
108 | struct pt_regs *regs) | |
cd5b61d6 RK |
109 | { |
110 | int err = 0; | |
111 | struct rt_sigframe __user *frame; | |
112 | struct hexagon_vdso *vdso = current->mm->context.vdso; | |
113 | ||
8bc77aa4 | 114 | frame = get_sigframe(ksig, regs, sizeof(struct rt_sigframe)); |
cd5b61d6 RK |
115 | |
116 | if (!access_ok(VERIFY_WRITE, frame, sizeof(struct rt_sigframe))) | |
ac443624 | 117 | return -EFAULT; |
cd5b61d6 | 118 | |
ac443624 RW |
119 | if (copy_siginfo_to_user(&frame->info, &ksig->info)) |
120 | return -EFAULT; | |
cd5b61d6 RK |
121 | |
122 | /* The on-stack signal trampoline is no longer executed; | |
123 | * however, the libgcc signal frame unwinding code checks for | |
124 | * the presence of these two numeric magic values. | |
125 | */ | |
126 | err |= __put_user(0x7800d166, &frame->tramp[0]); | |
127 | err |= __put_user(0x5400c004, &frame->tramp[1]); | |
128 | err |= setup_sigcontext(regs, &frame->uc.uc_mcontext); | |
129 | err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); | |
da36f98a | 130 | err |= __save_altstack(&frame->uc.uc_stack, user_stack_pointer(regs)); |
cd5b61d6 | 131 | if (err) |
ac443624 | 132 | return -EFAULT; |
cd5b61d6 RK |
133 | |
134 | /* Load r0/r1 pair with signumber/siginfo pointer... */ | |
135 | regs->r0100 = ((unsigned long long)((unsigned long)&frame->info) << 32) | |
ac443624 | 136 | | (unsigned long long)ksig->sig; |
cd5b61d6 RK |
137 | regs->r02 = (unsigned long) &frame->uc; |
138 | regs->r31 = (unsigned long) vdso->rt_signal_trampoline; | |
139 | pt_psp(regs) = (unsigned long) frame; | |
ac443624 | 140 | pt_set_elr(regs, (unsigned long)ksig->ka.sa.sa_handler); |
cd5b61d6 RK |
141 | |
142 | return 0; | |
cd5b61d6 RK |
143 | } |
144 | ||
145 | /* | |
146 | * Setup invocation of signal handler | |
147 | */ | |
ac443624 | 148 | static void handle_signal(struct ksignal *ksig, struct pt_regs *regs) |
cd5b61d6 | 149 | { |
ac443624 RW |
150 | int ret; |
151 | ||
cd5b61d6 RK |
152 | /* |
153 | * If we're handling a signal that aborted a system call, | |
154 | * set up the error return value before adding the signal | |
155 | * frame to the stack. | |
156 | */ | |
157 | ||
158 | if (regs->syscall_nr >= 0) { | |
159 | switch (regs->r00) { | |
160 | case -ERESTART_RESTARTBLOCK: | |
161 | case -ERESTARTNOHAND: | |
162 | regs->r00 = -EINTR; | |
163 | break; | |
164 | case -ERESTARTSYS: | |
ac443624 | 165 | if (!(ksig->ka.sa.sa_flags & SA_RESTART)) { |
cd5b61d6 RK |
166 | regs->r00 = -EINTR; |
167 | break; | |
168 | } | |
169 | /* Fall through */ | |
170 | case -ERESTARTNOINTR: | |
171 | regs->r06 = regs->syscall_nr; | |
172 | pt_set_elr(regs, pt_elr(regs) - 4); | |
173 | regs->r00 = regs->restart_r0; | |
174 | break; | |
175 | default: | |
176 | break; | |
177 | } | |
178 | } | |
179 | ||
180 | /* | |
181 | * Set up the stack frame; not doing the SA_SIGINFO thing. We | |
182 | * only set up the rt_frame flavor. | |
183 | */ | |
cd5b61d6 | 184 | /* If there was an error on setup, no signal was delivered. */ |
ac443624 | 185 | ret = setup_rt_frame(ksig, sigmask_to_save(), regs); |
cd5b61d6 | 186 | |
ac443624 | 187 | signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP)); |
cd5b61d6 RK |
188 | } |
189 | ||
190 | /* | |
191 | * Called from return-from-event code. | |
192 | */ | |
a11e67c2 | 193 | void do_signal(struct pt_regs *regs) |
cd5b61d6 | 194 | { |
ac443624 | 195 | struct ksignal ksig; |
cd5b61d6 RK |
196 | |
197 | if (!user_mode(regs)) | |
198 | return; | |
199 | ||
ac443624 RW |
200 | if (get_signal(&ksig)) { |
201 | handle_signal(&ksig, regs); | |
cd5b61d6 RK |
202 | return; |
203 | } | |
204 | ||
cd5b61d6 | 205 | /* |
a11e67c2 | 206 | * No (more) signals; if we came from a system call, handle the restart. |
cd5b61d6 | 207 | */ |
a11e67c2 | 208 | |
cd5b61d6 RK |
209 | if (regs->syscall_nr >= 0) { |
210 | switch (regs->r00) { | |
211 | case -ERESTARTNOHAND: | |
212 | case -ERESTARTSYS: | |
213 | case -ERESTARTNOINTR: | |
214 | regs->r06 = regs->syscall_nr; | |
215 | break; | |
216 | case -ERESTART_RESTARTBLOCK: | |
217 | regs->r06 = __NR_restart_syscall; | |
218 | break; | |
219 | default: | |
220 | goto no_restart; | |
221 | } | |
222 | pt_set_elr(regs, pt_elr(regs) - 4); | |
223 | regs->r00 = regs->restart_r0; | |
224 | } | |
225 | ||
226 | no_restart: | |
227 | /* If there's no signal to deliver, put the saved sigmask back */ | |
51a7b448 | 228 | restore_saved_sigmask(); |
cd5b61d6 RK |
229 | } |
230 | ||
cd5b61d6 RK |
231 | /* |
232 | * Architecture-specific wrappers for signal-related system calls | |
233 | */ | |
cd5b61d6 RK |
234 | |
235 | asmlinkage int sys_rt_sigreturn(void) | |
236 | { | |
99521855 | 237 | struct pt_regs *regs = current_pt_regs(); |
cd5b61d6 RK |
238 | struct rt_sigframe __user *frame; |
239 | sigset_t blocked; | |
240 | ||
ef9b122f | 241 | /* Always make any pending restarted system calls return -EINTR */ |
f56141e3 | 242 | current->restart_block.fn = do_no_restart_syscall; |
ef9b122f | 243 | |
cd5b61d6 RK |
244 | frame = (struct rt_sigframe __user *)pt_psp(regs); |
245 | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) | |
246 | goto badframe; | |
247 | if (__copy_from_user(&blocked, &frame->uc.uc_sigmask, sizeof(blocked))) | |
248 | goto badframe; | |
249 | ||
43aca324 | 250 | set_current_blocked(&blocked); |
cd5b61d6 RK |
251 | |
252 | if (restore_sigcontext(regs, &frame->uc.uc_mcontext)) | |
253 | goto badframe; | |
254 | ||
255 | /* Restore the user's stack as well */ | |
256 | pt_psp(regs) = regs->r29; | |
257 | ||
a11e67c2 | 258 | regs->syscall_nr = -1; |
cd5b61d6 | 259 | |
1e974c21 | 260 | if (restore_altstack(&frame->uc.uc_stack)) |
cd5b61d6 RK |
261 | goto badframe; |
262 | ||
a11e67c2 | 263 | return regs->r00; |
cd5b61d6 RK |
264 | |
265 | badframe: | |
266 | force_sig(SIGSEGV, current); | |
267 | return 0; | |
268 | } |