f80bac17c65c535f14f0ebc27071f11aa536f834
[linux-2.6.git] / arch / m32r / kernel / signal.c
1 /*
2  *  linux/arch/m32r/kernel/signal.c
3  *
4  *  Copyright (c) 2003  Hitoshi Yamamoto
5  *
6  *  Taken from i386 version.
7  *  Copyright (C) 1991, 1992  Linus Torvalds
8  *
9  *  1997-11-28  Modified for POSIX.1b signals by Richard Henderson
10  *  2000-06-20  Pentium III FXSR, SSE support by Gareth Hughes
11  */
12
13 #include <linux/sched.h>
14 #include <linux/mm.h>
15 #include <linux/smp.h>
16 #include <linux/kernel.h>
17 #include <linux/signal.h>
18 #include <linux/errno.h>
19 #include <linux/wait.h>
20 #include <linux/unistd.h>
21 #include <linux/stddef.h>
22 #include <linux/personality.h>
23 #include <linux/freezer.h>
24 #include <asm/cacheflush.h>
25 #include <asm/ucontext.h>
26 #include <asm/uaccess.h>
27
28 #define DEBUG_SIG 0
29
30 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
31
32 int do_signal(struct pt_regs *, sigset_t *);
33
34 asmlinkage int
35 sys_rt_sigsuspend(sigset_t __user *unewset, size_t sigsetsize,
36                   unsigned long r2, unsigned long r3, unsigned long r4,
37                   unsigned long r5, unsigned long r6, struct pt_regs *regs)
38 {
39         sigset_t newset;
40
41         /* XXX: Don't preclude handling different sized sigset_t's.  */
42         if (sigsetsize != sizeof(sigset_t))
43                 return -EINVAL;
44
45         if (copy_from_user(&newset, unewset, sizeof(newset)))
46                 return -EFAULT;
47         sigdelsetmask(&newset, sigmask(SIGKILL)|sigmask(SIGSTOP));
48
49         spin_lock_irq(&current->sighand->siglock);
50         current->saved_sigmask = current->blocked;
51         current->blocked = newset;
52         recalc_sigpending();
53         spin_unlock_irq(&current->sighand->siglock);
54
55         current->state = TASK_INTERRUPTIBLE;
56         schedule();
57         set_thread_flag(TIF_RESTORE_SIGMASK);
58         return -ERESTARTNOHAND;
59 }
60
61 asmlinkage int
62 sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
63                 unsigned long r2, unsigned long r3, unsigned long r4,
64                 unsigned long r5, unsigned long r6, struct pt_regs *regs)
65 {
66         return do_sigaltstack(uss, uoss, regs->spu);
67 }
68
69
70 /*
71  * Do a signal return; undo the signal stack.
72  */
73
74 struct rt_sigframe
75 {
76         int sig;
77         struct siginfo __user *pinfo;
78         void __user *puc;
79         struct siginfo info;
80         struct ucontext uc;
81 //      struct _fpstate fpstate;
82 };
83
84 static int
85 restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
86                    int *r0_p)
87 {
88         unsigned int err = 0;
89
90         /* Always make any pending restarted system calls return -EINTR */
91         current_thread_info()->restart_block.fn = do_no_restart_syscall;
92
93 #define COPY(x)         err |= __get_user(regs->x, &sc->sc_##x)
94         COPY(r4);
95         COPY(r5);
96         COPY(r6);
97         COPY(pt_regs);
98         /* COPY(r0); Skip r0 */
99         COPY(r1);
100         COPY(r2);
101         COPY(r3);
102         COPY(r7);
103         COPY(r8);
104         COPY(r9);
105         COPY(r10);
106         COPY(r11);
107         COPY(r12);
108         COPY(acc0h);
109         COPY(acc0l);
110         COPY(acc1h);            /* ISA_DSP_LEVEL2 only */
111         COPY(acc1l);            /* ISA_DSP_LEVEL2 only */
112         COPY(psw);
113         COPY(bpc);
114         COPY(bbpsw);
115         COPY(bbpc);
116         COPY(spu);
117         COPY(fp);
118         COPY(lr);
119         COPY(spi);
120 #undef COPY
121
122         regs->syscall_nr = -1;  /* disable syscall checks */
123         err |= __get_user(*r0_p, &sc->sc_r0);
124
125         return err;
126 }
127
128 asmlinkage int
129 sys_rt_sigreturn(unsigned long r0, unsigned long r1,
130                  unsigned long r2, unsigned long r3, unsigned long r4,
131                  unsigned long r5, unsigned long r6, struct pt_regs *regs)
132 {
133         struct rt_sigframe __user *frame = (struct rt_sigframe __user *)regs->spu;
134         sigset_t set;
135         int result;
136
137         if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
138                 goto badframe;
139         if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
140                 goto badframe;
141
142         sigdelsetmask(&set, ~_BLOCKABLE);
143         spin_lock_irq(&current->sighand->siglock);
144         current->blocked = set;
145         recalc_sigpending();
146         spin_unlock_irq(&current->sighand->siglock);
147
148         if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &result))
149                 goto badframe;
150
151         if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->spu) == -EFAULT)
152                 goto badframe;
153
154         return result;
155
156 badframe:
157         force_sig(SIGSEGV, current);
158         return 0;
159 }
160
161 /*
162  * Set up a signal frame.
163  */
164
165 static int
166 setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
167                  unsigned long mask)
168 {
169         int err = 0;
170
171 #define COPY(x) err |= __put_user(regs->x, &sc->sc_##x)
172         COPY(r4);
173         COPY(r5);
174         COPY(r6);
175         COPY(pt_regs);
176         COPY(r0);
177         COPY(r1);
178         COPY(r2);
179         COPY(r3);
180         COPY(r7);
181         COPY(r8);
182         COPY(r9);
183         COPY(r10);
184         COPY(r11);
185         COPY(r12);
186         COPY(acc0h);
187         COPY(acc0l);
188         COPY(acc1h);            /* ISA_DSP_LEVEL2 only */
189         COPY(acc1l);            /* ISA_DSP_LEVEL2 only */
190         COPY(psw);
191         COPY(bpc);
192         COPY(bbpsw);
193         COPY(bbpc);
194         COPY(spu);
195         COPY(fp);
196         COPY(lr);
197         COPY(spi);
198 #undef COPY
199
200         err |= __put_user(mask, &sc->oldmask);
201
202         return err;
203 }
204
205 /*
206  * Determine which stack to use..
207  */
208 static inline void __user *
209 get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
210 {
211         /* This is the X/Open sanctioned signal stack switching.  */
212         if (ka->sa.sa_flags & SA_ONSTACK) {
213                 if (sas_ss_flags(sp) == 0)
214                         sp = current->sas_ss_sp + current->sas_ss_size;
215         }
216
217         return (void __user *)((sp - frame_size) & -8ul);
218 }
219
220 static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
221                            sigset_t *set, struct pt_regs *regs)
222 {
223         struct rt_sigframe __user *frame;
224         int err = 0;
225         int signal;
226
227         frame = get_sigframe(ka, regs->spu, sizeof(*frame));
228
229         if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
230                 goto give_sigsegv;
231
232         signal = current_thread_info()->exec_domain
233                 && current_thread_info()->exec_domain->signal_invmap
234                 && sig < 32
235                 ? current_thread_info()->exec_domain->signal_invmap[sig]
236                 : sig;
237
238         err |= __put_user(signal, &frame->sig);
239         if (err)
240                 goto give_sigsegv;
241
242         err |= __put_user(&frame->info, &frame->pinfo);
243         err |= __put_user(&frame->uc, &frame->puc);
244         err |= copy_siginfo_to_user(&frame->info, info);
245         if (err)
246                 goto give_sigsegv;
247
248         /* Create the ucontext.  */
249         err |= __put_user(0, &frame->uc.uc_flags);
250         err |= __put_user(0, &frame->uc.uc_link);
251         err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
252         err |= __put_user(sas_ss_flags(regs->spu),
253                           &frame->uc.uc_stack.ss_flags);
254         err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
255         err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0]);
256         err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
257         if (err)
258                 goto give_sigsegv;
259
260         /* Set up to return from userspace.  */
261         regs->lr = (unsigned long)ka->sa.sa_restorer;
262
263         /* Set up registers for signal handler */
264         regs->spu = (unsigned long)frame;
265         regs->r0 = signal;      /* Arg for signal handler */
266         regs->r1 = (unsigned long)&frame->info;
267         regs->r2 = (unsigned long)&frame->uc;
268         regs->bpc = (unsigned long)ka->sa.sa_handler;
269
270         set_fs(USER_DS);
271
272 #if DEBUG_SIG
273         printk("SIG deliver (%s:%d): sp=%p pc=%p\n",
274                 current->comm, current->pid, frame, regs->pc);
275 #endif
276
277         return;
278
279 give_sigsegv:
280         force_sigsegv(sig, current);
281 }
282
283 /*
284  * OK, we're invoking a handler
285  */
286
287 static void
288 handle_signal(unsigned long sig, struct k_sigaction *ka, siginfo_t *info,
289               sigset_t *oldset, struct pt_regs *regs)
290 {
291         unsigned short inst;
292
293         /* Are we from a system call? */
294         if (regs->syscall_nr >= 0) {
295                 /* If so, check system call restarting.. */
296                 switch (regs->r0) {
297                         case -ERESTART_RESTARTBLOCK:
298                         case -ERESTARTNOHAND:
299                                 regs->r0 = -EINTR;
300                                 break;
301
302                         case -ERESTARTSYS:
303                                 if (!(ka->sa.sa_flags & SA_RESTART)) {
304                                         regs->r0 = -EINTR;
305                                         break;
306                                 }
307                         /* fallthrough */
308                         case -ERESTARTNOINTR:
309                                 regs->r0 = regs->orig_r0;
310                                 inst = *(unsigned short *)(regs->bpc - 2);
311                                 if ((inst & 0xfff0) == 0x10f0)  /* trap ? */
312                                         regs->bpc -= 2;
313                                 else
314                                         regs->bpc -= 4;
315                 }
316         }
317
318         /* Set up the stack frame */
319         setup_rt_frame(sig, ka, info, oldset, regs);
320
321         spin_lock_irq(&current->sighand->siglock);
322         sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
323         if (!(ka->sa.sa_flags & SA_NODEFER))
324                 sigaddset(&current->blocked,sig);
325         recalc_sigpending();
326         spin_unlock_irq(&current->sighand->siglock);
327 }
328
329 /*
330  * Note that 'init' is a special process: it doesn't get signals it doesn't
331  * want to handle. Thus you cannot kill init even with a SIGKILL even by
332  * mistake.
333  */
334 int do_signal(struct pt_regs *regs, sigset_t *oldset)
335 {
336         siginfo_t info;
337         int signr;
338         struct k_sigaction ka;
339         unsigned short inst;
340
341         /*
342          * We want the common case to go fast, which
343          * is why we may in certain cases get here from
344          * kernel mode. Just return without doing anything
345          * if so.
346          */
347         if (!user_mode(regs))
348                 return 1;
349
350         if (try_to_freeze()) 
351                 goto no_signal;
352
353         if (!oldset)
354                 oldset = &current->blocked;
355
356         signr = get_signal_to_deliver(&info, &ka, regs, NULL);
357         if (signr > 0) {
358                 /* Re-enable any watchpoints before delivering the
359                  * signal to user space. The processor register will
360                  * have been cleared if the watchpoint triggered
361                  * inside the kernel.
362                  */
363
364                 /* Whee!  Actually deliver the signal.  */
365                 handle_signal(signr, &ka, &info, oldset, regs);
366                 return 1;
367         }
368
369  no_signal:
370         /* Did we come from a system call? */
371         if (regs->syscall_nr >= 0) {
372                 /* Restart the system call - no handlers present */
373                 if (regs->r0 == -ERESTARTNOHAND ||
374                     regs->r0 == -ERESTARTSYS ||
375                     regs->r0 == -ERESTARTNOINTR) {
376                         regs->r0 = regs->orig_r0;
377                         inst = *(unsigned short *)(regs->bpc - 2);
378                         if ((inst & 0xfff0) == 0x10f0)  /* trap ? */
379                                 regs->bpc -= 2;
380                         else
381                                 regs->bpc -= 4;
382                 }
383                 if (regs->r0 == -ERESTART_RESTARTBLOCK){
384                         regs->r0 = regs->orig_r0;
385                         regs->r7 = __NR_restart_syscall;
386                         inst = *(unsigned short *)(regs->bpc - 2);
387                         if ((inst & 0xfff0) == 0x10f0)  /* trap ? */
388                                 regs->bpc -= 2;
389                         else
390                                 regs->bpc -= 4;
391                 }
392         }
393         return 0;
394 }
395
396 /*
397  * notification of userspace execution resumption
398  * - triggered by current->work.notify_resume
399  */
400 void do_notify_resume(struct pt_regs *regs, sigset_t *oldset,
401                       __u32 thread_info_flags)
402 {
403         /* Pending single-step? */
404         if (thread_info_flags & _TIF_SINGLESTEP)
405                 clear_thread_flag(TIF_SINGLESTEP);
406
407         /* deal with pending signal delivery */
408         if (thread_info_flags & _TIF_SIGPENDING)
409                 do_signal(regs,oldset);
410
411         if (thread_info_flags & _TIF_NOTIFY_RESUME) {
412                 clear_thread_flag(TIF_NOTIFY_RESUME);
413                 tracehook_notify_resume(regs);
414                 if (current->replacement_session_keyring)
415                         key_replace_session_keyring();
416         }
417
418         clear_thread_flag(TIF_IRET);
419 }