1 /*
2 * arch/score/kernel/signal.c
3 *
4 * Score Processor version.
5 *
6 * Copyright (C) 2009 Sunplus Core Technology Co., Ltd.
7 * Chen Liqin <liqin.chen@sunplusct.com>
8 * Lennox Wu <lennox.wu@sunplusct.com>
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, see the file COPYING, or write
22 * to the Free Software Foundation, Inc.,
23 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
24 */
25
26 #include <linux/errno.h>
27 #include <linux/signal.h>
28 #include <linux/ptrace.h>
29 #include <linux/unistd.h>
30 #include <linux/uaccess.h>
31 #include <linux/tracehook.h>
32
33 #include <asm/cacheflush.h>
34 #include <asm/syscalls.h>
35 #include <asm/ucontext.h>
36
37 struct rt_sigframe {
38 u32 rs_ass[4]; /* argument save space */
39 u32 rs_code[2]; /* signal trampoline */
40 struct siginfo rs_info;
41 struct ucontext rs_uc;
42 };
43
setup_sigcontext(struct pt_regs * regs,struct sigcontext __user * sc)44 static int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
45 {
46 int err = 0;
47 unsigned long reg;
48
49 reg = regs->cp0_epc; err |= __put_user(reg, &sc->sc_pc);
50 err |= __put_user(regs->cp0_psr, &sc->sc_psr);
51 err |= __put_user(regs->cp0_condition, &sc->sc_condition);
52
53
54 #define save_gp_reg(i) { \
55 reg = regs->regs[i]; \
56 err |= __put_user(reg, &sc->sc_regs[i]); \
57 } while (0)
58 save_gp_reg(0); save_gp_reg(1); save_gp_reg(2);
59 save_gp_reg(3); save_gp_reg(4); save_gp_reg(5);
60 save_gp_reg(6); save_gp_reg(7); save_gp_reg(8);
61 save_gp_reg(9); save_gp_reg(10); save_gp_reg(11);
62 save_gp_reg(12); save_gp_reg(13); save_gp_reg(14);
63 save_gp_reg(15); save_gp_reg(16); save_gp_reg(17);
64 save_gp_reg(18); save_gp_reg(19); save_gp_reg(20);
65 save_gp_reg(21); save_gp_reg(22); save_gp_reg(23);
66 save_gp_reg(24); save_gp_reg(25); save_gp_reg(26);
67 save_gp_reg(27); save_gp_reg(28); save_gp_reg(29);
68 #undef save_gp_reg
69
70 reg = regs->ceh; err |= __put_user(reg, &sc->sc_mdceh);
71 reg = regs->cel; err |= __put_user(reg, &sc->sc_mdcel);
72 err |= __put_user(regs->cp0_ecr, &sc->sc_ecr);
73 err |= __put_user(regs->cp0_ema, &sc->sc_ema);
74
75 return err;
76 }
77
restore_sigcontext(struct pt_regs * regs,struct sigcontext __user * sc)78 static int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
79 {
80 int err = 0;
81 u32 reg;
82
83 err |= __get_user(regs->cp0_epc, &sc->sc_pc);
84 err |= __get_user(regs->cp0_condition, &sc->sc_condition);
85
86 err |= __get_user(reg, &sc->sc_mdceh);
87 regs->ceh = (int) reg;
88 err |= __get_user(reg, &sc->sc_mdcel);
89 regs->cel = (int) reg;
90
91 err |= __get_user(reg, &sc->sc_psr);
92 regs->cp0_psr = (int) reg;
93 err |= __get_user(reg, &sc->sc_ecr);
94 regs->cp0_ecr = (int) reg;
95 err |= __get_user(reg, &sc->sc_ema);
96 regs->cp0_ema = (int) reg;
97
98 #define restore_gp_reg(i) do { \
99 err |= __get_user(reg, &sc->sc_regs[i]); \
100 regs->regs[i] = reg; \
101 } while (0)
102 restore_gp_reg(0); restore_gp_reg(1); restore_gp_reg(2);
103 restore_gp_reg(3); restore_gp_reg(4); restore_gp_reg(5);
104 restore_gp_reg(6); restore_gp_reg(7); restore_gp_reg(8);
105 restore_gp_reg(9); restore_gp_reg(10); restore_gp_reg(11);
106 restore_gp_reg(12); restore_gp_reg(13); restore_gp_reg(14);
107 restore_gp_reg(15); restore_gp_reg(16); restore_gp_reg(17);
108 restore_gp_reg(18); restore_gp_reg(19); restore_gp_reg(20);
109 restore_gp_reg(21); restore_gp_reg(22); restore_gp_reg(23);
110 restore_gp_reg(24); restore_gp_reg(25); restore_gp_reg(26);
111 restore_gp_reg(27); restore_gp_reg(28); restore_gp_reg(29);
112 #undef restore_gp_reg
113
114 return err;
115 }
116
117 /*
118 * Determine which stack to use..
119 */
get_sigframe(struct k_sigaction * ka,struct pt_regs * regs,size_t frame_size)120 static void __user *get_sigframe(struct k_sigaction *ka,
121 struct pt_regs *regs, size_t frame_size)
122 {
123 unsigned long sp;
124
125 /* Default to using normal stack */
126 sp = regs->regs[0];
127 sp -= 32;
128
129 /* This is the X/Open sanctioned signal stack switching. */
130 if ((ka->sa.sa_flags & SA_ONSTACK) && (!on_sig_stack(sp)))
131 sp = current->sas_ss_sp + current->sas_ss_size;
132
133 return (void __user*)((sp - frame_size) & ~7);
134 }
135
136 asmlinkage long
score_rt_sigreturn(struct pt_regs * regs)137 score_rt_sigreturn(struct pt_regs *regs)
138 {
139 struct rt_sigframe __user *frame;
140 sigset_t set;
141 int sig;
142
143 /* Always make any pending restarted system calls return -EINTR */
144 current->restart_block.fn = do_no_restart_syscall;
145
146 frame = (struct rt_sigframe __user *) regs->regs[0];
147 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
148 goto badframe;
149 if (__copy_from_user(&set, &frame->rs_uc.uc_sigmask, sizeof(set)))
150 goto badframe;
151
152 set_current_blocked(&set);
153
154 sig = restore_sigcontext(regs, &frame->rs_uc.uc_mcontext);
155 if (sig < 0)
156 goto badframe;
157 else if (sig)
158 force_sig(sig, current);
159
160 if (restore_altstack(&frame->rs_uc.uc_stack))
161 goto badframe;
162 regs->is_syscall = 0;
163
164 __asm__ __volatile__(
165 "mv\tr0, %0\n\t"
166 "la\tr8, syscall_exit\n\t"
167 "br\tr8\n\t"
168 : : "r" (regs) : "r8");
169
170 badframe:
171 force_sig(SIGSEGV, current);
172
173 return 0;
174 }
175
setup_rt_frame(struct ksignal * ksig,struct pt_regs * regs,sigset_t * set)176 static int setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs,
177 sigset_t *set)
178 {
179 struct rt_sigframe __user *frame;
180 int err = 0;
181
182 frame = get_sigframe(&ksig->ka, regs, sizeof(*frame));
183 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
184 return -EFAULT;
185
186 /*
187 * Set up the return code ...
188 *
189 * li v0, __NR_rt_sigreturn
190 * syscall
191 */
192 err |= __put_user(0x87788000 + __NR_rt_sigreturn*2,
193 frame->rs_code + 0);
194 err |= __put_user(0x80008002, frame->rs_code + 1);
195 flush_cache_sigtramp((unsigned long) frame->rs_code);
196
197 err |= copy_siginfo_to_user(&frame->rs_info, &ksig->info);
198 err |= __put_user(0, &frame->rs_uc.uc_flags);
199 err |= __put_user(NULL, &frame->rs_uc.uc_link);
200 err |= __save_altstack(&frame->rs_uc.uc_stack, regs->regs[0]);
201 err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext);
202 err |= __copy_to_user(&frame->rs_uc.uc_sigmask, set, sizeof(*set));
203
204 if (err)
205 return -EFAULT;
206
207 regs->regs[0] = (unsigned long) frame;
208 regs->regs[3] = (unsigned long) frame->rs_code;
209 regs->regs[4] = ksig->sig;
210 regs->regs[5] = (unsigned long) &frame->rs_info;
211 regs->regs[6] = (unsigned long) &frame->rs_uc;
212 regs->regs[29] = (unsigned long) ksig->ka.sa.sa_handler;
213 regs->cp0_epc = (unsigned long) ksig->ka.sa.sa_handler;
214
215 return 0;
216 }
217
handle_signal(struct ksignal * ksig,struct pt_regs * regs)218 static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
219 {
220 int ret;
221
222 if (regs->is_syscall) {
223 switch (regs->regs[4]) {
224 case ERESTART_RESTARTBLOCK:
225 case ERESTARTNOHAND:
226 regs->regs[4] = EINTR;
227 break;
228 case ERESTARTSYS:
229 if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
230 regs->regs[4] = EINTR;
231 break;
232 }
233 case ERESTARTNOINTR:
234 regs->regs[4] = regs->orig_r4;
235 regs->regs[7] = regs->orig_r7;
236 regs->cp0_epc -= 8;
237 }
238
239 regs->is_syscall = 0;
240 }
241
242 /*
243 * Set up the stack frame
244 */
245 ret = setup_rt_frame(ksig, regs, sigmask_to_save());
246
247 signal_setup_done(ret, ksig, 0);
248 }
249
do_signal(struct pt_regs * regs)250 static void do_signal(struct pt_regs *regs)
251 {
252 struct ksignal ksig;
253
254 /*
255 * We want the common case to go fast, which is why we may in certain
256 * cases get here from kernel mode. Just return without doing anything
257 * if so.
258 */
259 if (!user_mode(regs))
260 return;
261
262 if (get_signal(&ksig)) {
263 /* Actually deliver the signal. */
264 handle_signal(&ksig, regs);
265 return;
266 }
267
268 if (regs->is_syscall) {
269 if (regs->regs[4] == ERESTARTNOHAND ||
270 regs->regs[4] == ERESTARTSYS ||
271 regs->regs[4] == ERESTARTNOINTR) {
272 regs->regs[4] = regs->orig_r4;
273 regs->regs[7] = regs->orig_r7;
274 regs->cp0_epc -= 8;
275 }
276
277 if (regs->regs[4] == ERESTART_RESTARTBLOCK) {
278 regs->regs[27] = __NR_restart_syscall;
279 regs->regs[4] = regs->orig_r4;
280 regs->regs[7] = regs->orig_r7;
281 regs->cp0_epc -= 8;
282 }
283
284 regs->is_syscall = 0; /* Don't deal with this again. */
285 }
286
287 /*
288 * If there's no signal to deliver, we just put the saved sigmask
289 * back
290 */
291 restore_saved_sigmask();
292 }
293
294 /*
295 * notification of userspace execution resumption
296 * - triggered by the TIF_WORK_MASK flags
297 */
do_notify_resume(struct pt_regs * regs,void * unused,__u32 thread_info_flags)298 asmlinkage void do_notify_resume(struct pt_regs *regs, void *unused,
299 __u32 thread_info_flags)
300 {
301 /* deal with pending signal delivery */
302 if (thread_info_flags & _TIF_SIGPENDING)
303 do_signal(regs);
304 if (thread_info_flags & _TIF_NOTIFY_RESUME) {
305 clear_thread_flag(TIF_NOTIFY_RESUME);
306 tracehook_notify_resume(regs);
307 }
308 }
309