Linux 2.6.31.6
[linux/fpc-iii.git] / arch / blackfin / kernel / signal.c
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1 /*
2 * File: arch/blackfin/kernel/signal.c
3 * Based on:
4 * Author:
6 * Created:
7 * Description:
9 * Modified:
10 * Copyright 2004-2006 Analog Devices Inc.
12 * Bugs: Enter bugs at http://blackfin.uclinux.org/
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.
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.
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
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 #include <linux/uaccess.h>
39 #include <asm/cacheflush.h>
40 #include <asm/ucontext.h>
41 #include <asm/fixed_code.h>
43 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
45 /* Location of the trace bit in SYSCFG. */
46 #define TRACE_BITS 0x0001
48 struct fdpic_func_descriptor {
49 unsigned long text;
50 unsigned long GOT;
53 struct rt_sigframe {
54 int sig;
55 struct siginfo *pinfo;
56 void *puc;
57 /* This is no longer needed by the kernel, but unfortunately userspace
58 * code expects it to be there. */
59 char retcode[8];
60 struct siginfo info;
61 struct ucontext uc;
64 asmlinkage int sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss)
66 return do_sigaltstack(uss, uoss, rdusp());
69 static inline int
70 rt_restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *pr0)
72 unsigned long usp = 0;
73 int err = 0;
75 #define RESTORE(x) err |= __get_user(regs->x, &sc->sc_##x)
77 /* restore passed registers */
78 RESTORE(r0); RESTORE(r1); RESTORE(r2); RESTORE(r3);
79 RESTORE(r4); RESTORE(r5); RESTORE(r6); RESTORE(r7);
80 RESTORE(p0); RESTORE(p1); RESTORE(p2); RESTORE(p3);
81 RESTORE(p4); RESTORE(p5);
82 err |= __get_user(usp, &sc->sc_usp);
83 wrusp(usp);
84 RESTORE(a0w); RESTORE(a1w);
85 RESTORE(a0x); RESTORE(a1x);
86 RESTORE(astat);
87 RESTORE(rets);
88 RESTORE(pc);
89 RESTORE(retx);
90 RESTORE(fp);
91 RESTORE(i0); RESTORE(i1); RESTORE(i2); RESTORE(i3);
92 RESTORE(m0); RESTORE(m1); RESTORE(m2); RESTORE(m3);
93 RESTORE(l0); RESTORE(l1); RESTORE(l2); RESTORE(l3);
94 RESTORE(b0); RESTORE(b1); RESTORE(b2); RESTORE(b3);
95 RESTORE(lc0); RESTORE(lc1);
96 RESTORE(lt0); RESTORE(lt1);
97 RESTORE(lb0); RESTORE(lb1);
98 RESTORE(seqstat);
100 regs->orig_p0 = -1; /* disable syscall checks */
102 *pr0 = regs->r0;
103 return err;
106 asmlinkage int do_rt_sigreturn(unsigned long __unused)
108 struct pt_regs *regs = (struct pt_regs *)__unused;
109 unsigned long usp = rdusp();
110 struct rt_sigframe *frame = (struct rt_sigframe *)(usp);
111 sigset_t set;
112 int r0;
114 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
115 goto badframe;
116 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
117 goto badframe;
119 sigdelsetmask(&set, ~_BLOCKABLE);
120 spin_lock_irq(&current->sighand->siglock);
121 current->blocked = set;
122 recalc_sigpending();
123 spin_unlock_irq(&current->sighand->siglock);
125 if (rt_restore_sigcontext(regs, &frame->uc.uc_mcontext, &r0))
126 goto badframe;
128 if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->usp) == -EFAULT)
129 goto badframe;
131 return r0;
133 badframe:
134 force_sig(SIGSEGV, current);
135 return 0;
138 static inline int rt_setup_sigcontext(struct sigcontext *sc, struct pt_regs *regs)
140 int err = 0;
142 #define SETUP(x) err |= __put_user(regs->x, &sc->sc_##x)
144 SETUP(r0); SETUP(r1); SETUP(r2); SETUP(r3);
145 SETUP(r4); SETUP(r5); SETUP(r6); SETUP(r7);
146 SETUP(p0); SETUP(p1); SETUP(p2); SETUP(p3);
147 SETUP(p4); SETUP(p5);
148 err |= __put_user(rdusp(), &sc->sc_usp);
149 SETUP(a0w); SETUP(a1w);
150 SETUP(a0x); SETUP(a1x);
151 SETUP(astat);
152 SETUP(rets);
153 SETUP(pc);
154 SETUP(retx);
155 SETUP(fp);
156 SETUP(i0); SETUP(i1); SETUP(i2); SETUP(i3);
157 SETUP(m0); SETUP(m1); SETUP(m2); SETUP(m3);
158 SETUP(l0); SETUP(l1); SETUP(l2); SETUP(l3);
159 SETUP(b0); SETUP(b1); SETUP(b2); SETUP(b3);
160 SETUP(lc0); SETUP(lc1);
161 SETUP(lt0); SETUP(lt1);
162 SETUP(lb0); SETUP(lb1);
163 SETUP(seqstat);
165 return err;
168 static inline void *get_sigframe(struct k_sigaction *ka, struct pt_regs *regs,
169 size_t frame_size)
171 unsigned long usp;
173 /* Default to using normal stack. */
174 usp = rdusp();
176 /* This is the X/Open sanctioned signal stack switching. */
177 if (ka->sa.sa_flags & SA_ONSTACK) {
178 if (!on_sig_stack(usp))
179 usp = current->sas_ss_sp + current->sas_ss_size;
181 return (void *)((usp - frame_size) & -8UL);
184 static int
185 setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t * info,
186 sigset_t * set, struct pt_regs *regs)
188 struct rt_sigframe *frame;
189 int err = 0;
191 frame = get_sigframe(ka, regs, sizeof(*frame));
193 err |= __put_user((current_thread_info()->exec_domain
194 && current_thread_info()->exec_domain->signal_invmap
195 && sig < 32
196 ? current_thread_info()->exec_domain->
197 signal_invmap[sig] : sig), &frame->sig);
199 err |= __put_user(&frame->info, &frame->pinfo);
200 err |= __put_user(&frame->uc, &frame->puc);
201 err |= copy_siginfo_to_user(&frame->info, info);
203 /* Create the ucontext. */
204 err |= __put_user(0, &frame->uc.uc_flags);
205 err |= __put_user(0, &frame->uc.uc_link);
206 err |=
207 __put_user((void *)current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
208 err |= __put_user(sas_ss_flags(rdusp()), &frame->uc.uc_stack.ss_flags);
209 err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
210 err |= rt_setup_sigcontext(&frame->uc.uc_mcontext, regs);
211 err |= copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
213 if (err)
214 goto give_sigsegv;
216 /* Set up registers for signal handler */
217 wrusp((unsigned long)frame);
218 if (current->personality & FDPIC_FUNCPTRS) {
219 struct fdpic_func_descriptor __user *funcptr =
220 (struct fdpic_func_descriptor *) ka->sa.sa_handler;
221 __get_user(regs->pc, &funcptr->text);
222 __get_user(regs->p3, &funcptr->GOT);
223 } else
224 regs->pc = (unsigned long)ka->sa.sa_handler;
225 regs->rets = SIGRETURN_STUB;
227 regs->r0 = frame->sig;
228 regs->r1 = (unsigned long)(&frame->info);
229 regs->r2 = (unsigned long)(&frame->uc);
232 * Clear the trace flag when entering the signal handler, but
233 * notify any tracer that was single-stepping it. The tracer
234 * may want to single-step inside the handler too.
236 if (regs->syscfg & TRACE_BITS) {
237 regs->syscfg &= ~TRACE_BITS;
238 ptrace_notify(SIGTRAP);
241 return 0;
243 give_sigsegv:
244 if (sig == SIGSEGV)
245 ka->sa.sa_handler = SIG_DFL;
246 force_sig(SIGSEGV, current);
247 return -EFAULT;
250 static inline void
251 handle_restart(struct pt_regs *regs, struct k_sigaction *ka, int has_handler)
253 switch (regs->r0) {
254 case -ERESTARTNOHAND:
255 if (!has_handler)
256 goto do_restart;
257 regs->r0 = -EINTR;
258 break;
260 case -ERESTARTSYS:
261 if (has_handler && !(ka->sa.sa_flags & SA_RESTART)) {
262 regs->r0 = -EINTR;
263 break;
265 /* fallthrough */
266 case -ERESTARTNOINTR:
267 do_restart:
268 regs->p0 = regs->orig_p0;
269 regs->r0 = regs->orig_r0;
270 regs->pc -= 2;
271 break;
276 * OK, we're invoking a handler
278 static int
279 handle_signal(int sig, siginfo_t *info, struct k_sigaction *ka,
280 sigset_t *oldset, struct pt_regs *regs)
282 int ret;
284 /* are we from a system call? to see pt_regs->orig_p0 */
285 if (regs->orig_p0 >= 0)
286 /* If so, check system call restarting.. */
287 handle_restart(regs, ka, 1);
289 /* set up the stack frame */
290 ret = setup_rt_frame(sig, ka, info, oldset, regs);
292 if (ret == 0) {
293 spin_lock_irq(&current->sighand->siglock);
294 sigorsets(&current->blocked, &current->blocked,
295 &ka->sa.sa_mask);
296 if (!(ka->sa.sa_flags & SA_NODEFER))
297 sigaddset(&current->blocked, sig);
298 recalc_sigpending();
299 spin_unlock_irq(&current->sighand->siglock);
301 return ret;
305 * Note that 'init' is a special process: it doesn't get signals it doesn't
306 * want to handle. Thus you cannot kill init even with a SIGKILL even by
307 * mistake.
309 * Note that we go through the signals twice: once to check the signals
310 * that the kernel can handle, and then we build all the user-level signal
311 * handling stack-frames in one go after that.
313 asmlinkage void do_signal(struct pt_regs *regs)
315 siginfo_t info;
316 int signr;
317 struct k_sigaction ka;
318 sigset_t *oldset;
320 current->thread.esp0 = (unsigned long)regs;
322 if (try_to_freeze())
323 goto no_signal;
325 if (test_thread_flag(TIF_RESTORE_SIGMASK))
326 oldset = &current->saved_sigmask;
327 else
328 oldset = &current->blocked;
330 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
331 if (signr > 0) {
332 /* Whee! Actually deliver the signal. */
333 if (handle_signal(signr, &info, &ka, oldset, regs) == 0) {
334 /* a signal was successfully delivered; the saved
335 * sigmask will have been stored in the signal frame,
336 * and will be restored by sigreturn, so we can simply
337 * clear the TIF_RESTORE_SIGMASK flag */
338 if (test_thread_flag(TIF_RESTORE_SIGMASK))
339 clear_thread_flag(TIF_RESTORE_SIGMASK);
342 return;
345 no_signal:
346 /* Did we come from a system call? */
347 if (regs->orig_p0 >= 0)
348 /* Restart the system call - no handlers present */
349 handle_restart(regs, NULL, 0);
351 /* if there's no signal to deliver, we just put the saved sigmask
352 * back */
353 if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
354 clear_thread_flag(TIF_RESTORE_SIGMASK);
355 sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);