Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
[deliverable/linux.git] / arch / score / kernel / signal.c
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
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
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 */
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
137 score_sigaltstack(struct pt_regs *regs)
138 {
139 const stack_t __user *uss = (const stack_t __user *) regs->regs[4];
140 stack_t __user *uoss = (stack_t __user *) regs->regs[5];
141 unsigned long usp = regs->regs[0];
142
143 return do_sigaltstack(uss, uoss, usp);
144 }
145
146 asmlinkage long
147 score_rt_sigreturn(struct pt_regs *regs)
148 {
149 struct rt_sigframe __user *frame;
150 sigset_t set;
151 int sig;
152
153 /* Always make any pending restarted system calls return -EINTR */
154 current_thread_info()->restart_block.fn = do_no_restart_syscall;
155
156 frame = (struct rt_sigframe __user *) regs->regs[0];
157 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
158 goto badframe;
159 if (__copy_from_user(&set, &frame->rs_uc.uc_sigmask, sizeof(set)))
160 goto badframe;
161
162 set_current_blocked(&set);
163
164 sig = restore_sigcontext(regs, &frame->rs_uc.uc_mcontext);
165 if (sig < 0)
166 goto badframe;
167 else if (sig)
168 force_sig(sig, current);
169
170 /* It is more difficult to avoid calling this function than to
171 call it and ignore errors. */
172 if (do_sigaltstack(&frame->rs_uc.uc_stack, NULL, regs->regs[0]) == -EFAULT)
173 goto badframe;
174 regs->is_syscall = 0;
175
176 __asm__ __volatile__(
177 "mv\tr0, %0\n\t"
178 "la\tr8, syscall_exit\n\t"
179 "br\tr8\n\t"
180 : : "r" (regs) : "r8");
181
182 badframe:
183 force_sig(SIGSEGV, current);
184
185 return 0;
186 }
187
188 static int setup_rt_frame(struct k_sigaction *ka, struct pt_regs *regs,
189 int signr, sigset_t *set, siginfo_t *info)
190 {
191 struct rt_sigframe __user *frame;
192 int err = 0;
193
194 frame = get_sigframe(ka, regs, sizeof(*frame));
195 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
196 goto give_sigsegv;
197
198 /*
199 * Set up the return code ...
200 *
201 * li v0, __NR_rt_sigreturn
202 * syscall
203 */
204 err |= __put_user(0x87788000 + __NR_rt_sigreturn*2,
205 frame->rs_code + 0);
206 err |= __put_user(0x80008002, frame->rs_code + 1);
207 flush_cache_sigtramp((unsigned long) frame->rs_code);
208
209 err |= copy_siginfo_to_user(&frame->rs_info, info);
210 err |= __put_user(0, &frame->rs_uc.uc_flags);
211 err |= __put_user(NULL, &frame->rs_uc.uc_link);
212 err |= __put_user((void __user *)current->sas_ss_sp,
213 &frame->rs_uc.uc_stack.ss_sp);
214 err |= __put_user(sas_ss_flags(regs->regs[0]),
215 &frame->rs_uc.uc_stack.ss_flags);
216 err |= __put_user(current->sas_ss_size,
217 &frame->rs_uc.uc_stack.ss_size);
218 err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext);
219 err |= __copy_to_user(&frame->rs_uc.uc_sigmask, set, sizeof(*set));
220
221 if (err)
222 goto give_sigsegv;
223
224 regs->regs[0] = (unsigned long) frame;
225 regs->regs[3] = (unsigned long) frame->rs_code;
226 regs->regs[4] = signr;
227 regs->regs[5] = (unsigned long) &frame->rs_info;
228 regs->regs[6] = (unsigned long) &frame->rs_uc;
229 regs->regs[29] = (unsigned long) ka->sa.sa_handler;
230 regs->cp0_epc = (unsigned long) ka->sa.sa_handler;
231
232 return 0;
233
234 give_sigsegv:
235 force_sigsegv(signr, current);
236 return -EFAULT;
237 }
238
239 static void handle_signal(unsigned long sig, siginfo_t *info,
240 struct k_sigaction *ka, struct pt_regs *regs)
241 {
242 if (regs->is_syscall) {
243 switch (regs->regs[4]) {
244 case ERESTART_RESTARTBLOCK:
245 case ERESTARTNOHAND:
246 regs->regs[4] = EINTR;
247 break;
248 case ERESTARTSYS:
249 if (!(ka->sa.sa_flags & SA_RESTART)) {
250 regs->regs[4] = EINTR;
251 break;
252 }
253 case ERESTARTNOINTR:
254 regs->regs[4] = regs->orig_r4;
255 regs->regs[7] = regs->orig_r7;
256 regs->cp0_epc -= 8;
257 }
258
259 regs->is_syscall = 0;
260 }
261
262 /*
263 * Set up the stack frame
264 */
265 if (setup_rt_frame(ka, regs, sig, sigmask_to_save(), info) < 0)
266 return;
267
268 signal_delivered(sig, info, ka, regs, 0);
269 }
270
271 static void do_signal(struct pt_regs *regs)
272 {
273 struct k_sigaction ka;
274 siginfo_t info;
275 int signr;
276
277 /*
278 * We want the common case to go fast, which is why we may in certain
279 * cases get here from kernel mode. Just return without doing anything
280 * if so.
281 */
282 if (!user_mode(regs))
283 return;
284
285 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
286 if (signr > 0) {
287 /* Actually deliver the signal. */
288 handle_signal(signr, &info, &ka, regs);
289 return;
290 }
291
292 if (regs->is_syscall) {
293 if (regs->regs[4] == ERESTARTNOHAND ||
294 regs->regs[4] == ERESTARTSYS ||
295 regs->regs[4] == ERESTARTNOINTR) {
296 regs->regs[4] = regs->orig_r4;
297 regs->regs[7] = regs->orig_r7;
298 regs->cp0_epc -= 8;
299 }
300
301 if (regs->regs[4] == ERESTART_RESTARTBLOCK) {
302 regs->regs[27] = __NR_restart_syscall;
303 regs->regs[4] = regs->orig_r4;
304 regs->regs[7] = regs->orig_r7;
305 regs->cp0_epc -= 8;
306 }
307
308 regs->is_syscall = 0; /* Don't deal with this again. */
309 }
310
311 /*
312 * If there's no signal to deliver, we just put the saved sigmask
313 * back
314 */
315 restore_saved_sigmask();
316 }
317
318 /*
319 * notification of userspace execution resumption
320 * - triggered by the TIF_WORK_MASK flags
321 */
322 asmlinkage void do_notify_resume(struct pt_regs *regs, void *unused,
323 __u32 thread_info_flags)
324 {
325 /* deal with pending signal delivery */
326 if (thread_info_flags & _TIF_SIGPENDING)
327 do_signal(regs);
328 if (thread_info_flags & _TIF_NOTIFY_RESUME) {
329 clear_thread_flag(TIF_NOTIFY_RESUME);
330 tracehook_notify_resume(regs);
331 }
332 }
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