blob: f5d0e1c37ea263950d03d33a6edb50ce0966da81 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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"
Linus Torvalds1da177e2005-04-16 15:20:36 -070013#include "sigcontext.h"
14#include "registers.h"
15#include "mode.h"
16
17#ifdef CONFIG_MODE_SKAS
18
19#include "skas.h"
20
21static int copy_sc_from_user_skas(struct pt_regs *regs,
Al Viro4d338e12006-03-31 02:30:15 -080022 struct sigcontext __user *from)
Linus Torvalds1da177e2005-04-16 15:20:36 -070023{
24 struct sigcontext sc;
25 unsigned long fpregs[HOST_FP_SIZE];
26 int err;
27
28 err = copy_from_user(&sc, from, sizeof(sc));
29 err |= copy_from_user(fpregs, sc.fpstate, sizeof(fpregs));
30 if(err)
31 return(err);
32
33 REGS_GS(regs->regs.skas.regs) = sc.gs;
34 REGS_FS(regs->regs.skas.regs) = sc.fs;
35 REGS_ES(regs->regs.skas.regs) = sc.es;
36 REGS_DS(regs->regs.skas.regs) = sc.ds;
37 REGS_EDI(regs->regs.skas.regs) = sc.edi;
38 REGS_ESI(regs->regs.skas.regs) = sc.esi;
39 REGS_EBP(regs->regs.skas.regs) = sc.ebp;
40 REGS_SP(regs->regs.skas.regs) = sc.esp;
41 REGS_EBX(regs->regs.skas.regs) = sc.ebx;
42 REGS_EDX(regs->regs.skas.regs) = sc.edx;
43 REGS_ECX(regs->regs.skas.regs) = sc.ecx;
44 REGS_EAX(regs->regs.skas.regs) = sc.eax;
45 REGS_IP(regs->regs.skas.regs) = sc.eip;
46 REGS_CS(regs->regs.skas.regs) = sc.cs;
47 REGS_EFLAGS(regs->regs.skas.regs) = sc.eflags;
48 REGS_SS(regs->regs.skas.regs) = sc.ss;
Linus Torvalds1da177e2005-04-16 15:20:36 -070049
50 err = restore_fp_registers(userspace_pid[0], fpregs);
51 if(err < 0){
52 printk("copy_sc_from_user_skas - PTRACE_SETFPREGS failed, "
53 "errno = %d\n", err);
54 return(1);
55 }
56
57 return(0);
58}
59
Al Viro4d338e12006-03-31 02:30:15 -080060int copy_sc_to_user_skas(struct sigcontext *to, struct _fpstate __user *to_fp,
Jeff Dike98c18232006-03-27 01:14:38 -080061 struct pt_regs *regs, unsigned long sp)
Linus Torvalds1da177e2005-04-16 15:20:36 -070062{
63 struct sigcontext sc;
64 unsigned long fpregs[HOST_FP_SIZE];
Bodo Stroesserc5784552005-05-05 16:15:31 -070065 struct faultinfo * fi = &current->thread.arch.faultinfo;
Linus Torvalds1da177e2005-04-16 15:20:36 -070066 int err;
67
68 sc.gs = REGS_GS(regs->regs.skas.regs);
69 sc.fs = REGS_FS(regs->regs.skas.regs);
70 sc.es = REGS_ES(regs->regs.skas.regs);
71 sc.ds = REGS_DS(regs->regs.skas.regs);
72 sc.edi = REGS_EDI(regs->regs.skas.regs);
73 sc.esi = REGS_ESI(regs->regs.skas.regs);
74 sc.ebp = REGS_EBP(regs->regs.skas.regs);
Jeff Dike98c18232006-03-27 01:14:38 -080075 sc.esp = sp;
Linus Torvalds1da177e2005-04-16 15:20:36 -070076 sc.ebx = REGS_EBX(regs->regs.skas.regs);
77 sc.edx = REGS_EDX(regs->regs.skas.regs);
78 sc.ecx = REGS_ECX(regs->regs.skas.regs);
79 sc.eax = REGS_EAX(regs->regs.skas.regs);
80 sc.eip = REGS_IP(regs->regs.skas.regs);
81 sc.cs = REGS_CS(regs->regs.skas.regs);
82 sc.eflags = REGS_EFLAGS(regs->regs.skas.regs);
83 sc.esp_at_signal = regs->regs.skas.regs[UESP];
84 sc.ss = regs->regs.skas.regs[SS];
Bodo Stroesserc5784552005-05-05 16:15:31 -070085 sc.cr2 = fi->cr2;
86 sc.err = fi->error_code;
87 sc.trapno = fi->trap_no;
Linus Torvalds1da177e2005-04-16 15:20:36 -070088
89 err = save_fp_registers(userspace_pid[0], fpregs);
90 if(err < 0){
91 printk("copy_sc_to_user_skas - PTRACE_GETFPREGS failed, "
92 "errno = %d\n", err);
93 return(1);
94 }
Al Viro4d338e12006-03-31 02:30:15 -080095 to_fp = (to_fp ? to_fp : (struct _fpstate __user *) (to + 1));
Linus Torvalds1da177e2005-04-16 15:20:36 -070096 sc.fpstate = to_fp;
97
98 if(err)
99 return(err);
100
101 return(copy_to_user(to, &sc, sizeof(sc)) ||
102 copy_to_user(to_fp, fpregs, sizeof(fpregs)));
103}
104#endif
105
106#ifdef CONFIG_MODE_TT
107
108/* These copy a sigcontext to/from userspace. They copy the fpstate pointer,
109 * blowing away the old, good one. So, that value is saved, and then restored
110 * after the sigcontext copy. In copy_from, the variable holding the saved
111 * fpstate pointer, and the sigcontext that it should be restored to are both
112 * in the kernel, so we can just restore using an assignment. In copy_to, the
113 * saved pointer is in the kernel, but the sigcontext is in userspace, so we
114 * copy_to_user it.
115 */
Al Viro4d338e12006-03-31 02:30:15 -0800116int copy_sc_from_user_tt(struct sigcontext *to, struct sigcontext __user *from,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117 int fpsize)
118{
Al Viro4d338e12006-03-31 02:30:15 -0800119 struct _fpstate *to_fp;
120 struct _fpstate __user *from_fp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121 unsigned long sigs;
122 int err;
123
124 to_fp = to->fpstate;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125 sigs = to->oldmask;
126 err = copy_from_user(to, from, sizeof(*to));
Al Viroe54a5df2005-09-03 15:57:27 -0700127 from_fp = to->fpstate;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128 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
Al Viro4d338e12006-03-31 02:30:15 -0800135int copy_sc_to_user_tt(struct sigcontext *to, struct _fpstate __user *fp,
Jeff Dike98c18232006-03-27 01:14:38 -0800136 struct sigcontext *from, int fpsize, unsigned long sp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137{
Al Viro4d338e12006-03-31 02:30:15 -0800138 struct _fpstate __user *to_fp;
139 struct _fpstate *from_fp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140 int err;
141
Al Viro4d338e12006-03-31 02:30:15 -0800142 to_fp = (fp ? fp : (struct _fpstate __user *) (to + 1));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143 from_fp = from->fpstate;
144 err = copy_to_user(to, from, sizeof(*to));
Jeff Dike98c18232006-03-27 01:14:38 -0800145
146 /* The SP in the sigcontext is the updated one for the signal
147 * delivery. The sp passed in is the original, and this needs
148 * to be restored, so we stick it in separately.
149 */
150 err |= copy_to_user(&SC_SP(to), sp, sizeof(sp));
151
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152 if(from_fp != NULL){
153 err |= copy_to_user(&to->fpstate, &to_fp, sizeof(to->fpstate));
154 err |= copy_to_user(to_fp, from_fp, fpsize);
155 }
Jeff Dike98c18232006-03-27 01:14:38 -0800156 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157}
158#endif
159
160static int copy_sc_from_user(struct pt_regs *to, void __user *from)
161{
162 int ret;
163
164 ret = CHOOSE_MODE(copy_sc_from_user_tt(UPT_SC(&to->regs), from,
165 sizeof(struct _fpstate)),
166 copy_sc_from_user_skas(to, from));
167 return(ret);
168}
169
Al Viro4d338e12006-03-31 02:30:15 -0800170static int copy_sc_to_user(struct sigcontext *to, struct _fpstate __user *fp,
Jeff Dike98c18232006-03-27 01:14:38 -0800171 struct pt_regs *from, unsigned long sp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172{
173 return(CHOOSE_MODE(copy_sc_to_user_tt(to, fp, UPT_SC(&from->regs),
Jeff Dike98c18232006-03-27 01:14:38 -0800174 sizeof(*fp), sp),
175 copy_sc_to_user_skas(to, fp, from, sp)));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176}
177
Al Viro4d338e12006-03-31 02:30:15 -0800178static int copy_ucontext_to_user(struct ucontext __user *uc, struct _fpstate __user *fp,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179 sigset_t *set, unsigned long sp)
180{
181 int err = 0;
182
183 err |= put_user(current->sas_ss_sp, &uc->uc_stack.ss_sp);
184 err |= put_user(sas_ss_flags(sp), &uc->uc_stack.ss_flags);
185 err |= put_user(current->sas_ss_size, &uc->uc_stack.ss_size);
Jeff Dike98c18232006-03-27 01:14:38 -0800186 err |= copy_sc_to_user(&uc->uc_mcontext, fp, &current->thread.regs, sp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187 err |= copy_to_user(&uc->uc_sigmask, set, sizeof(*set));
188 return(err);
189}
190
191struct sigframe
192{
Al Viro4d338e12006-03-31 02:30:15 -0800193 char __user *pretcode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194 int sig;
195 struct sigcontext sc;
196 struct _fpstate fpstate;
197 unsigned long extramask[_NSIG_WORDS-1];
198 char retcode[8];
199};
200
201struct rt_sigframe
202{
Al Viro4d338e12006-03-31 02:30:15 -0800203 char __user *pretcode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204 int sig;
Al Viro4d338e12006-03-31 02:30:15 -0800205 struct siginfo __user *pinfo;
206 void __user *puc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207 struct siginfo info;
208 struct ucontext uc;
209 struct _fpstate fpstate;
210 char retcode[8];
211};
212
213int setup_signal_stack_sc(unsigned long stack_top, int sig,
214 struct k_sigaction *ka, struct pt_regs *regs,
215 sigset_t *mask)
216{
217 struct sigframe __user *frame;
Al Viro4d338e12006-03-31 02:30:15 -0800218 void __user *restorer;
Jeff Dike98c18232006-03-27 01:14:38 -0800219 unsigned long save_sp = PT_REGS_SP(regs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 int err = 0;
221
222 stack_top &= -8UL;
Al Viro4d338e12006-03-31 02:30:15 -0800223 frame = (struct sigframe __user *) stack_top - 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
225 return 1;
226
Al Viro4d338e12006-03-31 02:30:15 -0800227 restorer = frame->retcode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228 if(ka->sa.sa_flags & SA_RESTORER)
229 restorer = ka->sa.sa_restorer;
230
Jeff Dike98c18232006-03-27 01:14:38 -0800231 /* Update SP now because the page fault handler refuses to extend
232 * the stack if the faulting address is too far below the current
233 * SP, which frame now certainly is. If there's an error, the original
234 * value is restored on the way out.
235 * When writing the sigcontext to the stack, we have to write the
236 * original value, so that's passed to copy_sc_to_user, which does
237 * the right thing with it.
238 */
239 PT_REGS_SP(regs) = (unsigned long) frame;
240
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241 err |= __put_user(restorer, &frame->pretcode);
242 err |= __put_user(sig, &frame->sig);
Jeff Dike98c18232006-03-27 01:14:38 -0800243 err |= copy_sc_to_user(&frame->sc, NULL, regs, save_sp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244 err |= __put_user(mask->sig[0], &frame->sc.oldmask);
245 if (_NSIG_WORDS > 1)
246 err |= __copy_to_user(&frame->extramask, &mask->sig[1],
247 sizeof(frame->extramask));
248
249 /*
250 * This is popl %eax ; movl $,%eax ; int $0x80
251 *
252 * WE DO NOT USE IT ANY MORE! It's only left here for historical
253 * reasons and because gdb uses it as a signature to notice
254 * signal handler stack frames.
255 */
256 err |= __put_user(0xb858, (short __user *)(frame->retcode+0));
257 err |= __put_user(__NR_sigreturn, (int __user *)(frame->retcode+2));
258 err |= __put_user(0x80cd, (short __user *)(frame->retcode+6));
259
260 if(err)
Jeff Dike98c18232006-03-27 01:14:38 -0800261 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262
263 PT_REGS_SP(regs) = (unsigned long) frame;
264 PT_REGS_IP(regs) = (unsigned long) ka->sa.sa_handler;
265 PT_REGS_EAX(regs) = (unsigned long) sig;
266 PT_REGS_EDX(regs) = (unsigned long) 0;
267 PT_REGS_ECX(regs) = (unsigned long) 0;
268
269 if ((current->ptrace & PT_DTRACE) && (current->ptrace & PT_PTRACED))
270 ptrace_notify(SIGTRAP);
Jeff Dike98c18232006-03-27 01:14:38 -0800271 return 0;
272
273err:
274 PT_REGS_SP(regs) = save_sp;
275 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276}
277
278int setup_signal_stack_si(unsigned long stack_top, int sig,
279 struct k_sigaction *ka, struct pt_regs *regs,
280 siginfo_t *info, sigset_t *mask)
281{
282 struct rt_sigframe __user *frame;
Al Viro4d338e12006-03-31 02:30:15 -0800283 void __user *restorer;
Jeff Dike98c18232006-03-27 01:14:38 -0800284 unsigned long save_sp = PT_REGS_SP(regs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285 int err = 0;
286
287 stack_top &= -8UL;
Al Viro4d338e12006-03-31 02:30:15 -0800288 frame = (struct rt_sigframe __user *) stack_top - 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
290 return 1;
291
Al Viro4d338e12006-03-31 02:30:15 -0800292 restorer = frame->retcode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700293 if(ka->sa.sa_flags & SA_RESTORER)
294 restorer = ka->sa.sa_restorer;
295
Jeff Dike98c18232006-03-27 01:14:38 -0800296 /* See comment above about why this is here */
297 PT_REGS_SP(regs) = (unsigned long) frame;
298
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299 err |= __put_user(restorer, &frame->pretcode);
300 err |= __put_user(sig, &frame->sig);
301 err |= __put_user(&frame->info, &frame->pinfo);
302 err |= __put_user(&frame->uc, &frame->puc);
303 err |= copy_siginfo_to_user(&frame->info, info);
304 err |= copy_ucontext_to_user(&frame->uc, &frame->fpstate, mask,
Jeff Dike98c18232006-03-27 01:14:38 -0800305 save_sp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700306
307 /*
308 * This is movl $,%eax ; int $0x80
309 *
310 * WE DO NOT USE IT ANY MORE! It's only left here for historical
311 * reasons and because gdb uses it as a signature to notice
312 * signal handler stack frames.
313 */
314 err |= __put_user(0xb8, (char __user *)(frame->retcode+0));
315 err |= __put_user(__NR_rt_sigreturn, (int __user *)(frame->retcode+1));
316 err |= __put_user(0x80cd, (short __user *)(frame->retcode+5));
317
318 if(err)
Jeff Dike98c18232006-03-27 01:14:38 -0800319 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700320
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321 PT_REGS_IP(regs) = (unsigned long) ka->sa.sa_handler;
322 PT_REGS_EAX(regs) = (unsigned long) sig;
323 PT_REGS_EDX(regs) = (unsigned long) &frame->info;
324 PT_REGS_ECX(regs) = (unsigned long) &frame->uc;
325
326 if ((current->ptrace & PT_DTRACE) && (current->ptrace & PT_PTRACED))
327 ptrace_notify(SIGTRAP);
Jeff Dike98c18232006-03-27 01:14:38 -0800328 return 0;
329
330err:
331 PT_REGS_SP(regs) = save_sp;
332 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700333}
334
335long sys_sigreturn(struct pt_regs regs)
336{
337 unsigned long sp = PT_REGS_SP(&current->thread.regs);
Al Viro4d338e12006-03-31 02:30:15 -0800338 struct sigframe __user *frame = (struct sigframe __user *)(sp - 8);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700339 sigset_t set;
340 struct sigcontext __user *sc = &frame->sc;
341 unsigned long __user *oldmask = &sc->oldmask;
342 unsigned long __user *extramask = frame->extramask;
343 int sig_size = (_NSIG_WORDS - 1) * sizeof(unsigned long);
344
Andrew Morton350d5bd2005-06-25 14:55:19 -0700345 if(copy_from_user(&set.sig[0], oldmask, sizeof(set.sig[0])) ||
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346 copy_from_user(&set.sig[1], extramask, 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, sc))
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
368long sys_rt_sigreturn(struct pt_regs regs)
369{
Al Viro4d338e12006-03-31 02:30:15 -0800370 unsigned long sp = PT_REGS_SP(&current->thread.regs);
371 struct rt_sigframe __user *frame = (struct rt_sigframe __user *) (sp - 4);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700372 sigset_t set;
373 struct ucontext __user *uc = &frame->uc;
374 int sig_size = _NSIG_WORDS * sizeof(unsigned long);
375
376 if(copy_from_user(&set, &uc->uc_sigmask, sig_size))
377 goto segfault;
378
379 sigdelsetmask(&set, ~_BLOCKABLE);
380
381 spin_lock_irq(&current->sighand->siglock);
382 current->blocked = set;
383 recalc_sigpending();
384 spin_unlock_irq(&current->sighand->siglock);
385
386 if(copy_sc_from_user(&current->thread.regs, &uc->uc_mcontext))
387 goto segfault;
388
389 /* Avoid ERESTART handling */
390 PT_REGS_SYSCALL_NR(&current->thread.regs) = -1;
391 return(PT_REGS_SYSCALL_RET(&current->thread.regs));
392
393 segfault:
394 force_sig(SIGSEGV, current);
395 return 0;
396}
397
398/*
399 * Overrides for Emacs so that we follow Linus's tabbing style.
400 * Emacs will notice this stuff at the end of the file and automatically
401 * adjust the settings for this buffer only. This must remain at the end
402 * of the file.
403 * ---------------------------------------------------------------------------
404 * Local variables:
405 * c-file-style: "linux"
406 * End:
407 */