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-rw-r--r--arch/blackfin/kernel/signal.c356
1 files changed, 356 insertions, 0 deletions
diff --git a/arch/blackfin/kernel/signal.c b/arch/blackfin/kernel/signal.c
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1/*
2 * File: arch/blackfin/kernel/signal.c
3 * Based on:
4 * Author:
5 *
6 * Created:
7 * Description:
8 *
9 * Modified:
10 * Copyright 2004-2006 Analog Devices Inc.
11 *
12 * Bugs: Enter bugs at http://blackfin.uclinux.org/
13 *
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or
17 * (at your option) any later version.
18 *
19 * This program is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU General Public License for more details.
23 *
24 * You should have received a copy of the GNU General Public License
25 * along with this program; if not, see the file COPYING, or write
26 * to the Free Software Foundation, Inc.,
27 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
28 */
29
30#include <linux/signal.h>
31#include <linux/syscalls.h>
32#include <linux/ptrace.h>
33#include <linux/tty.h>
34#include <linux/personality.h>
35#include <linux/binfmts.h>
36#include <linux/freezer.h>
37
38#include <asm/uaccess.h>
39#include <asm/cacheflush.h>
40#include <asm/ucontext.h>
41
42#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
43
44struct fdpic_func_descriptor {
45 unsigned long text;
46 unsigned long GOT;
47};
48
49struct rt_sigframe {
50 int sig;
51 struct siginfo *pinfo;
52 void *puc;
53 char retcode[8];
54 struct siginfo info;
55 struct ucontext uc;
56};
57
58asmlinkage int sys_sigaltstack(const stack_t * uss, stack_t * uoss)
59{
60 return do_sigaltstack(uss, uoss, rdusp());
61}
62
63static inline int
64rt_restore_sigcontext(struct pt_regs *regs, struct sigcontext *sc, int *pr0)
65{
66 unsigned long usp = 0;
67 int err = 0;
68
69#define RESTORE(x) err |= __get_user(regs->x, &sc->sc_##x)
70
71 /* restore passed registers */
72 RESTORE(r0); RESTORE(r1); RESTORE(r2); RESTORE(r3);
73 RESTORE(r4); RESTORE(r5); RESTORE(r6); RESTORE(r7);
74 RESTORE(p0); RESTORE(p1); RESTORE(p2); RESTORE(p3);
75 RESTORE(p4); RESTORE(p5);
76 err |= __get_user(usp, &sc->sc_usp);
77 wrusp(usp);
78 RESTORE(a0w); RESTORE(a1w);
79 RESTORE(a0x); RESTORE(a1x);
80 RESTORE(astat);
81 RESTORE(rets);
82 RESTORE(pc);
83 RESTORE(retx);
84 RESTORE(fp);
85 RESTORE(i0); RESTORE(i1); RESTORE(i2); RESTORE(i3);
86 RESTORE(m0); RESTORE(m1); RESTORE(m2); RESTORE(m3);
87 RESTORE(l0); RESTORE(l1); RESTORE(l2); RESTORE(l3);
88 RESTORE(b0); RESTORE(b1); RESTORE(b2); RESTORE(b3);
89 RESTORE(lc0); RESTORE(lc1);
90 RESTORE(lt0); RESTORE(lt1);
91 RESTORE(lb0); RESTORE(lb1);
92 RESTORE(seqstat);
93
94 regs->orig_p0 = -1; /* disable syscall checks */
95
96 *pr0 = regs->r0;
97 return err;
98}
99
100asmlinkage int do_rt_sigreturn(unsigned long __unused)
101{
102 struct pt_regs *regs = (struct pt_regs *)__unused;
103 unsigned long usp = rdusp();
104 struct rt_sigframe *frame = (struct rt_sigframe *)(usp);
105 sigset_t set;
106 int r0;
107
108 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
109 goto badframe;
110 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
111 goto badframe;
112
113 sigdelsetmask(&set, ~_BLOCKABLE);
114 spin_lock_irq(&current->sighand->siglock);
115 current->blocked = set;
116 recalc_sigpending();
117 spin_unlock_irq(&current->sighand->siglock);
118
119 if (rt_restore_sigcontext(regs, &frame->uc.uc_mcontext, &r0))
120 goto badframe;
121
122 if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->usp) == -EFAULT)
123 goto badframe;
124
125 return r0;
126
127 badframe:
128 force_sig(SIGSEGV, current);
129 return 0;
130}
131
132static inline int rt_setup_sigcontext(struct sigcontext *sc, struct pt_regs *regs)
133{
134 int err = 0;
135
136#define SETUP(x) err |= __put_user(regs->x, &sc->sc_##x)
137
138 SETUP(r0); SETUP(r1); SETUP(r2); SETUP(r3);
139 SETUP(r4); SETUP(r5); SETUP(r6); SETUP(r7);
140 SETUP(p0); SETUP(p1); SETUP(p2); SETUP(p3);
141 SETUP(p4); SETUP(p5);
142 err |= __put_user(rdusp(), &sc->sc_usp);
143 SETUP(a0w); SETUP(a1w);
144 SETUP(a0x); SETUP(a1x);
145 SETUP(astat);
146 SETUP(rets);
147 SETUP(pc);
148 SETUP(retx);
149 SETUP(fp);
150 SETUP(i0); SETUP(i1); SETUP(i2); SETUP(i3);
151 SETUP(m0); SETUP(m1); SETUP(m2); SETUP(m3);
152 SETUP(l0); SETUP(l1); SETUP(l2); SETUP(l3);
153 SETUP(b0); SETUP(b1); SETUP(b2); SETUP(b3);
154 SETUP(lc0); SETUP(lc1);
155 SETUP(lt0); SETUP(lt1);
156 SETUP(lb0); SETUP(lb1);
157 SETUP(seqstat);
158
159 return err;
160}
161
162static inline void push_cache(unsigned long vaddr, unsigned int len)
163{
164 flush_icache_range(vaddr, vaddr + len);
165}
166
167static inline void *get_sigframe(struct k_sigaction *ka, struct pt_regs *regs,
168 size_t frame_size)
169{
170 unsigned long usp;
171
172 /* Default to using normal stack. */
173 usp = rdusp();
174
175 /* This is the X/Open sanctioned signal stack switching. */
176 if (ka->sa.sa_flags & SA_ONSTACK) {
177 if (!on_sig_stack(usp))
178 usp = current->sas_ss_sp + current->sas_ss_size;
179 }
180 return (void *)((usp - frame_size) & -8UL);
181}
182
183static int
184setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t * info,
185 sigset_t * set, struct pt_regs *regs)
186{
187 struct rt_sigframe *frame;
188 int err = 0;
189
190 frame = get_sigframe(ka, regs, sizeof(*frame));
191
192 err |= __put_user((current_thread_info()->exec_domain
193 && current_thread_info()->exec_domain->signal_invmap
194 && sig < 32
195 ? current_thread_info()->exec_domain->
196 signal_invmap[sig] : sig), &frame->sig);
197
198 err |= __put_user(&frame->info, &frame->pinfo);
199 err |= __put_user(&frame->uc, &frame->puc);
200 err |= copy_siginfo_to_user(&frame->info, info);
201
202 /* Create the ucontext. */
203 err |= __put_user(0, &frame->uc.uc_flags);
204 err |= __put_user(0, &frame->uc.uc_link);
205 err |=
206 __put_user((void *)current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
207 err |= __put_user(sas_ss_flags(rdusp()), &frame->uc.uc_stack.ss_flags);
208 err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
209 err |= rt_setup_sigcontext(&frame->uc.uc_mcontext, regs);
210 err |= copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
211
212 /* Set up to return from userspace. */
213 err |= __put_user(0x28, &(frame->retcode[0]));
214 err |= __put_user(0xe1, &(frame->retcode[1]));
215 err |= __put_user(0xad, &(frame->retcode[2]));
216 err |= __put_user(0x00, &(frame->retcode[3]));
217 err |= __put_user(0xa0, &(frame->retcode[4]));
218 err |= __put_user(0x00, &(frame->retcode[5]));
219
220 if (err)
221 goto give_sigsegv;
222
223 push_cache((unsigned long)&frame->retcode, sizeof(frame->retcode));
224
225 /* Set up registers for signal handler */
226 wrusp((unsigned long)frame);
227 if (get_personality & FDPIC_FUNCPTRS) {
228 struct fdpic_func_descriptor __user *funcptr =
229 (struct fdpic_func_descriptor *) ka->sa.sa_handler;
230 __get_user(regs->pc, &funcptr->text);
231 __get_user(regs->p3, &funcptr->GOT);
232 } else
233 regs->pc = (unsigned long)ka->sa.sa_handler;
234 regs->rets = (unsigned long)(frame->retcode);
235
236 regs->r0 = frame->sig;
237 regs->r1 = (unsigned long)(&frame->info);
238 regs->r2 = (unsigned long)(&frame->uc);
239
240 return 0;
241
242 give_sigsegv:
243 if (sig == SIGSEGV)
244 ka->sa.sa_handler = SIG_DFL;
245 force_sig(SIGSEGV, current);
246 return -EFAULT;
247}
248
249static inline void
250handle_restart(struct pt_regs *regs, struct k_sigaction *ka, int has_handler)
251{
252 switch (regs->r0) {
253 case -ERESTARTNOHAND:
254 if (!has_handler)
255 goto do_restart;
256 regs->r0 = -EINTR;
257 break;
258
259 case -ERESTARTSYS:
260 if (has_handler && !(ka->sa.sa_flags & SA_RESTART)) {
261 regs->r0 = -EINTR;
262 break;
263 }
264 /* fallthrough */
265 case -ERESTARTNOINTR:
266 do_restart:
267 regs->p0 = regs->orig_p0;
268 regs->r0 = regs->orig_r0;
269 regs->pc -= 2;
270 break;
271 }
272}
273
274/*
275 * OK, we're invoking a handler
276 */
277static int
278handle_signal(int sig, siginfo_t *info, struct k_sigaction *ka,
279 sigset_t *oldset, struct pt_regs *regs)
280{
281 int ret;
282
283 /* are we from a system call? to see pt_regs->orig_p0 */
284 if (regs->orig_p0 >= 0)
285 /* If so, check system call restarting.. */
286 handle_restart(regs, ka, 1);
287
288 /* set up the stack frame */
289 ret = setup_rt_frame(sig, ka, info, oldset, regs);
290
291 if (ret == 0) {
292 spin_lock_irq(&current->sighand->siglock);
293 sigorsets(&current->blocked, &current->blocked,
294 &ka->sa.sa_mask);
295 if (!(ka->sa.sa_flags & SA_NODEFER))
296 sigaddset(&current->blocked, sig);
297 recalc_sigpending();
298 spin_unlock_irq(&current->sighand->siglock);
299 }
300 return ret;
301}
302
303/*
304 * Note that 'init' is a special process: it doesn't get signals it doesn't
305 * want to handle. Thus you cannot kill init even with a SIGKILL even by
306 * mistake.
307 *
308 * Note that we go through the signals twice: once to check the signals
309 * that the kernel can handle, and then we build all the user-level signal
310 * handling stack-frames in one go after that.
311 */
312asmlinkage void do_signal(struct pt_regs *regs)
313{
314 siginfo_t info;
315 int signr;
316 struct k_sigaction ka;
317 sigset_t *oldset;
318
319 current->thread.esp0 = (unsigned long)regs;
320
321 if (try_to_freeze())
322 goto no_signal;
323
324 if (test_thread_flag(TIF_RESTORE_SIGMASK))
325 oldset = &current->saved_sigmask;
326 else
327 oldset = &current->blocked;
328
329 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
330 if (signr > 0) {
331 /* Whee! Actually deliver the signal. */
332 if (handle_signal(signr, &info, &ka, oldset, regs) == 0) {
333 /* a signal was successfully delivered; the saved
334 * sigmask will have been stored in the signal frame,
335 * and will be restored by sigreturn, so we can simply
336 * clear the TIF_RESTORE_SIGMASK flag */
337 if (test_thread_flag(TIF_RESTORE_SIGMASK))
338 clear_thread_flag(TIF_RESTORE_SIGMASK);
339 }
340
341 return;
342 }
343
344no_signal:
345 /* Did we come from a system call? */
346 if (regs->orig_p0 >= 0)
347 /* Restart the system call - no handlers present */
348 handle_restart(regs, NULL, 0);
349
350 /* if there's no signal to deliver, we just put the saved sigmask
351 * back */
352 if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
353 clear_thread_flag(TIF_RESTORE_SIGMASK);
354 sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
355 }
356}
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