Merge linux-2.6 with linux-acpi-2.6
[linux-2.6] / arch / um / sys-i386 / signal.c
1 /*
2  * Copyright (C) 2004 Jeff Dike (jdike@addtoit.com)
3  * Licensed under the GPL
4  */
5
6 #include "linux/signal.h"
7 #include "linux/ptrace.h"
8 #include "asm/current.h"
9 #include "asm/ucontext.h"
10 #include "asm/uaccess.h"
11 #include "asm/unistd.h"
12 #include "frame_kern.h"
13 #include "signal_user.h"
14 #include "sigcontext.h"
15 #include "registers.h"
16 #include "mode.h"
17
18 #ifdef CONFIG_MODE_SKAS
19
20 #include "skas.h"
21
22 static int copy_sc_from_user_skas(struct pt_regs *regs,
23                                   struct sigcontext *from)
24 {
25         struct sigcontext sc;
26         unsigned long fpregs[HOST_FP_SIZE];
27         int err;
28
29         err = copy_from_user(&sc, from, sizeof(sc));
30         err |= copy_from_user(fpregs, sc.fpstate, sizeof(fpregs));
31         if(err)
32                 return(err);
33
34         REGS_GS(regs->regs.skas.regs) = sc.gs;
35         REGS_FS(regs->regs.skas.regs) = sc.fs;
36         REGS_ES(regs->regs.skas.regs) = sc.es;
37         REGS_DS(regs->regs.skas.regs) = sc.ds;
38         REGS_EDI(regs->regs.skas.regs) = sc.edi;
39         REGS_ESI(regs->regs.skas.regs) = sc.esi;
40         REGS_EBP(regs->regs.skas.regs) = sc.ebp;
41         REGS_SP(regs->regs.skas.regs) = sc.esp;
42         REGS_EBX(regs->regs.skas.regs) = sc.ebx;
43         REGS_EDX(regs->regs.skas.regs) = sc.edx;
44         REGS_ECX(regs->regs.skas.regs) = sc.ecx;
45         REGS_EAX(regs->regs.skas.regs) = sc.eax;
46         REGS_IP(regs->regs.skas.regs) = sc.eip;
47         REGS_CS(regs->regs.skas.regs) = sc.cs;
48         REGS_EFLAGS(regs->regs.skas.regs) = sc.eflags;
49         REGS_SS(regs->regs.skas.regs) = sc.ss;
50
51         err = restore_fp_registers(userspace_pid[0], fpregs);
52         if(err < 0){
53                 printk("copy_sc_from_user_skas - PTRACE_SETFPREGS failed, "
54                        "errno = %d\n", err);
55                 return(1);
56         }
57
58         return(0);
59 }
60
61 int copy_sc_to_user_skas(struct sigcontext *to, struct _fpstate *to_fp,
62                          struct pt_regs *regs)
63 {
64         struct sigcontext sc;
65         unsigned long fpregs[HOST_FP_SIZE];
66         struct faultinfo * fi = &current->thread.arch.faultinfo;
67         int err;
68
69         sc.gs = REGS_GS(regs->regs.skas.regs);
70         sc.fs = REGS_FS(regs->regs.skas.regs);
71         sc.es = REGS_ES(regs->regs.skas.regs);
72         sc.ds = REGS_DS(regs->regs.skas.regs);
73         sc.edi = REGS_EDI(regs->regs.skas.regs);
74         sc.esi = REGS_ESI(regs->regs.skas.regs);
75         sc.ebp = REGS_EBP(regs->regs.skas.regs);
76         sc.esp = REGS_SP(regs->regs.skas.regs);
77         sc.ebx = REGS_EBX(regs->regs.skas.regs);
78         sc.edx = REGS_EDX(regs->regs.skas.regs);
79         sc.ecx = REGS_ECX(regs->regs.skas.regs);
80         sc.eax = REGS_EAX(regs->regs.skas.regs);
81         sc.eip = REGS_IP(regs->regs.skas.regs);
82         sc.cs = REGS_CS(regs->regs.skas.regs);
83         sc.eflags = REGS_EFLAGS(regs->regs.skas.regs);
84         sc.esp_at_signal = regs->regs.skas.regs[UESP];
85         sc.ss = regs->regs.skas.regs[SS];
86         sc.cr2 = fi->cr2;
87         sc.err = fi->error_code;
88         sc.trapno = fi->trap_no;
89
90         err = save_fp_registers(userspace_pid[0], fpregs);
91         if(err < 0){
92                 printk("copy_sc_to_user_skas - PTRACE_GETFPREGS failed, "
93                        "errno = %d\n", err);
94                 return(1);
95         }
96         to_fp = (to_fp ? to_fp : (struct _fpstate *) (to + 1));
97         sc.fpstate = to_fp;
98
99         if(err)
100                 return(err);
101
102         return(copy_to_user(to, &sc, sizeof(sc)) ||
103                copy_to_user(to_fp, fpregs, sizeof(fpregs)));
104 }
105 #endif
106
107 #ifdef CONFIG_MODE_TT
108
109 /* These copy a sigcontext to/from userspace.  They copy the fpstate pointer,
110  * blowing away the old, good one.  So, that value is saved, and then restored
111  * after the sigcontext copy.  In copy_from, the variable holding the saved
112  * fpstate pointer, and the sigcontext that it should be restored to are both
113  * in the kernel, so we can just restore using an assignment.  In copy_to, the
114  * saved pointer is in the kernel, but the sigcontext is in userspace, so we
115  * copy_to_user it.
116  */
117 int copy_sc_from_user_tt(struct sigcontext *to, struct sigcontext *from,
118                          int fpsize)
119 {
120         struct _fpstate *to_fp, *from_fp;
121         unsigned long sigs;
122         int err;
123
124         to_fp = to->fpstate;
125         sigs = to->oldmask;
126         err = copy_from_user(to, from, sizeof(*to));
127         from_fp = to->fpstate;
128         to->oldmask = sigs;
129         to->fpstate = to_fp;
130         if(to_fp != NULL)
131                 err |= copy_from_user(to_fp, from_fp, fpsize);
132         return(err);
133 }
134
135 int copy_sc_to_user_tt(struct sigcontext *to, struct _fpstate *fp,
136                        struct sigcontext *from, int fpsize)
137 {
138         struct _fpstate *to_fp, *from_fp;
139         int err;
140
141         to_fp = (fp ? fp : (struct _fpstate *) (to + 1));
142         from_fp = from->fpstate;
143         err = copy_to_user(to, from, sizeof(*to));
144         if(from_fp != NULL){
145                 err |= copy_to_user(&to->fpstate, &to_fp, sizeof(to->fpstate));
146                 err |= copy_to_user(to_fp, from_fp, fpsize);
147         }
148         return(err);
149 }
150 #endif
151
152 static int copy_sc_from_user(struct pt_regs *to, void __user *from)
153 {
154         int ret;
155
156         ret = CHOOSE_MODE(copy_sc_from_user_tt(UPT_SC(&to->regs), from,
157                                                sizeof(struct _fpstate)),
158                           copy_sc_from_user_skas(to, from));
159         return(ret);
160 }
161
162 static int copy_sc_to_user(struct sigcontext *to, struct _fpstate *fp,
163                            struct pt_regs *from)
164 {
165         return(CHOOSE_MODE(copy_sc_to_user_tt(to, fp, UPT_SC(&from->regs),
166                                               sizeof(*fp)),
167                            copy_sc_to_user_skas(to, fp, from)));
168 }
169
170 static int copy_ucontext_to_user(struct ucontext *uc, struct _fpstate *fp,
171                                  sigset_t *set, unsigned long sp)
172 {
173         int err = 0;
174
175         err |= put_user(current->sas_ss_sp, &uc->uc_stack.ss_sp);
176         err |= put_user(sas_ss_flags(sp), &uc->uc_stack.ss_flags);
177         err |= put_user(current->sas_ss_size, &uc->uc_stack.ss_size);
178         err |= copy_sc_to_user(&uc->uc_mcontext, fp, &current->thread.regs);
179         err |= copy_to_user(&uc->uc_sigmask, set, sizeof(*set));
180         return(err);
181 }
182
183 struct sigframe
184 {
185         char *pretcode;
186         int sig;
187         struct sigcontext sc;
188         struct _fpstate fpstate;
189         unsigned long extramask[_NSIG_WORDS-1];
190         char retcode[8];
191 };
192
193 struct rt_sigframe
194 {
195         char *pretcode;
196         int sig;
197         struct siginfo *pinfo;
198         void *puc;
199         struct siginfo info;
200         struct ucontext uc;
201         struct _fpstate fpstate;
202         char retcode[8];
203 };
204
205 int setup_signal_stack_sc(unsigned long stack_top, int sig,
206                           struct k_sigaction *ka, struct pt_regs *regs,
207                           sigset_t *mask)
208 {
209         struct sigframe __user *frame;
210         void *restorer;
211         int err = 0;
212
213         stack_top &= -8UL;
214         frame = (struct sigframe *) stack_top - 1;
215         if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
216                 return 1;
217
218         restorer = (void *) frame->retcode;
219         if(ka->sa.sa_flags & SA_RESTORER)
220                 restorer = ka->sa.sa_restorer;
221
222         err |= __put_user(restorer, &frame->pretcode);
223         err |= __put_user(sig, &frame->sig);
224         err |= copy_sc_to_user(&frame->sc, NULL, regs);
225         err |= __put_user(mask->sig[0], &frame->sc.oldmask);
226         if (_NSIG_WORDS > 1)
227                 err |= __copy_to_user(&frame->extramask, &mask->sig[1],
228                                       sizeof(frame->extramask));
229
230         /*
231          * This is popl %eax ; movl $,%eax ; int $0x80
232          *
233          * WE DO NOT USE IT ANY MORE! It's only left here for historical
234          * reasons and because gdb uses it as a signature to notice
235          * signal handler stack frames.
236          */
237         err |= __put_user(0xb858, (short __user *)(frame->retcode+0));
238         err |= __put_user(__NR_sigreturn, (int __user *)(frame->retcode+2));
239         err |= __put_user(0x80cd, (short __user *)(frame->retcode+6));
240
241         if(err)
242                 return(err);
243
244         PT_REGS_SP(regs) = (unsigned long) frame;
245         PT_REGS_IP(regs) = (unsigned long) ka->sa.sa_handler;
246         PT_REGS_EAX(regs) = (unsigned long) sig;
247         PT_REGS_EDX(regs) = (unsigned long) 0;
248         PT_REGS_ECX(regs) = (unsigned long) 0;
249
250         if ((current->ptrace & PT_DTRACE) && (current->ptrace & PT_PTRACED))
251                 ptrace_notify(SIGTRAP);
252         return(0);
253 }
254
255 int setup_signal_stack_si(unsigned long stack_top, int sig,
256                           struct k_sigaction *ka, struct pt_regs *regs,
257                           siginfo_t *info, sigset_t *mask)
258 {
259         struct rt_sigframe __user *frame;
260         void *restorer;
261         int err = 0;
262
263         stack_top &= -8UL;
264         frame = (struct rt_sigframe *) stack_top - 1;
265         if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
266                 return 1;
267
268         restorer = (void *) frame->retcode;
269         if(ka->sa.sa_flags & SA_RESTORER)
270                 restorer = ka->sa.sa_restorer;
271
272         err |= __put_user(restorer, &frame->pretcode);
273         err |= __put_user(sig, &frame->sig);
274         err |= __put_user(&frame->info, &frame->pinfo);
275         err |= __put_user(&frame->uc, &frame->puc);
276         err |= copy_siginfo_to_user(&frame->info, info);
277         err |= copy_ucontext_to_user(&frame->uc, &frame->fpstate, mask,
278                                      PT_REGS_SP(regs));
279
280         /*
281          * This is movl $,%eax ; int $0x80
282          *
283          * WE DO NOT USE IT ANY MORE! It's only left here for historical
284          * reasons and because gdb uses it as a signature to notice
285          * signal handler stack frames.
286          */
287         err |= __put_user(0xb8, (char __user *)(frame->retcode+0));
288         err |= __put_user(__NR_rt_sigreturn, (int __user *)(frame->retcode+1));
289         err |= __put_user(0x80cd, (short __user *)(frame->retcode+5));
290
291         if(err)
292                 return(err);
293
294         PT_REGS_SP(regs) = (unsigned long) frame;
295         PT_REGS_IP(regs) = (unsigned long) ka->sa.sa_handler;
296         PT_REGS_EAX(regs) = (unsigned long) sig;
297         PT_REGS_EDX(regs) = (unsigned long) &frame->info;
298         PT_REGS_ECX(regs) = (unsigned long) &frame->uc;
299
300         if ((current->ptrace & PT_DTRACE) && (current->ptrace & PT_PTRACED))
301                 ptrace_notify(SIGTRAP);
302         return(0);
303 }
304
305 long sys_sigreturn(struct pt_regs regs)
306 {
307         unsigned long sp = PT_REGS_SP(&current->thread.regs);
308         struct sigframe __user *frame = (struct sigframe *)(sp - 8);
309         sigset_t set;
310         struct sigcontext __user *sc = &frame->sc;
311         unsigned long __user *oldmask = &sc->oldmask;
312         unsigned long __user *extramask = frame->extramask;
313         int sig_size = (_NSIG_WORDS - 1) * sizeof(unsigned long);
314
315         if(copy_from_user(&set.sig[0], oldmask, sizeof(set.sig[0])) ||
316            copy_from_user(&set.sig[1], extramask, sig_size))
317                 goto segfault;
318
319         sigdelsetmask(&set, ~_BLOCKABLE);
320
321         spin_lock_irq(&current->sighand->siglock);
322         current->blocked = set;
323         recalc_sigpending();
324         spin_unlock_irq(&current->sighand->siglock);
325
326         if(copy_sc_from_user(&current->thread.regs, sc))
327                 goto segfault;
328
329         /* Avoid ERESTART handling */
330         PT_REGS_SYSCALL_NR(&current->thread.regs) = -1;
331         return(PT_REGS_SYSCALL_RET(&current->thread.regs));
332
333  segfault:
334         force_sig(SIGSEGV, current);
335         return 0;
336 }
337
338 long sys_rt_sigreturn(struct pt_regs regs)
339 {
340         unsigned long __user sp = PT_REGS_SP(&current->thread.regs);
341         struct rt_sigframe __user *frame = (struct rt_sigframe *) (sp - 4);
342         sigset_t set;
343         struct ucontext __user *uc = &frame->uc;
344         int sig_size = _NSIG_WORDS * sizeof(unsigned long);
345
346         if(copy_from_user(&set, &uc->uc_sigmask, sig_size))
347                 goto segfault;
348
349         sigdelsetmask(&set, ~_BLOCKABLE);
350
351         spin_lock_irq(&current->sighand->siglock);
352         current->blocked = set;
353         recalc_sigpending();
354         spin_unlock_irq(&current->sighand->siglock);
355
356         if(copy_sc_from_user(&current->thread.regs, &uc->uc_mcontext))
357                 goto segfault;
358
359         /* Avoid ERESTART handling */
360         PT_REGS_SYSCALL_NR(&current->thread.regs) = -1;
361         return(PT_REGS_SYSCALL_RET(&current->thread.regs));
362
363  segfault:
364         force_sig(SIGSEGV, current);
365         return 0;
366 }
367
368 /*
369  * Overrides for Emacs so that we follow Linus's tabbing style.
370  * Emacs will notice this stuff at the end of the file and automatically
371  * adjust the settings for this buffer only.  This must remain at the end
372  * of the file.
373  * ---------------------------------------------------------------------------
374  * Local variables:
375  * c-file-style: "linux"
376  * End:
377  */