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1/*
2 * arch/sparc64/kernel/signal.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 * Copyright (C) 1995, 2008 David S. Miller (davem@davemloft.net)
6 * Copyright (C) 1996 Miguel de Icaza (miguel@nuclecu.unam.mx)
7 * Copyright (C) 1997 Eddie C. Dost (ecd@skynet.be)
8 * Copyright (C) 1997,1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
9 */
10
11#ifdef CONFIG_COMPAT
12#include <linux/compat.h> /* for compat_old_sigset_t */
13#endif
14#include <linux/sched.h>
15#include <linux/kernel.h>
16#include <linux/signal.h>
17#include <linux/errno.h>
18#include <linux/wait.h>
19#include <linux/ptrace.h>
20#include <linux/tracehook.h>
21#include <linux/unistd.h>
22#include <linux/mm.h>
23#include <linux/tty.h>
24#include <linux/binfmts.h>
25#include <linux/bitops.h>
26
27#include <asm/uaccess.h>
28#include <asm/ptrace.h>
29#include <asm/pgtable.h>
30#include <asm/fpumacro.h>
31#include <asm/uctx.h>
32#include <asm/siginfo.h>
33#include <asm/visasm.h>
34#include <asm/switch_to.h>
35#include <asm/cacheflush.h>
36
37#include "entry.h"
38#include "systbls.h"
39#include "sigutil.h"
40
41/* {set, get}context() needed for 64-bit SparcLinux userland. */
42asmlinkage void sparc64_set_context(struct pt_regs *regs)
43{
44 struct ucontext __user *ucp = (struct ucontext __user *)
45 regs->u_regs[UREG_I0];
46 mc_gregset_t __user *grp;
47 unsigned long pc, npc, tstate;
48 unsigned long fp, i7;
49 unsigned char fenab;
50 int err;
51
52 flush_user_windows();
53 if (get_thread_wsaved() ||
54 (((unsigned long)ucp) & (sizeof(unsigned long)-1)) ||
55 (!__access_ok(ucp, sizeof(*ucp))))
56 goto do_sigsegv;
57 grp = &ucp->uc_mcontext.mc_gregs;
58 err = __get_user(pc, &((*grp)[MC_PC]));
59 err |= __get_user(npc, &((*grp)[MC_NPC]));
60 if (err || ((pc | npc) & 3))
61 goto do_sigsegv;
62 if (regs->u_regs[UREG_I1]) {
63 sigset_t set;
64
65 if (_NSIG_WORDS == 1) {
66 if (__get_user(set.sig[0], &ucp->uc_sigmask.sig[0]))
67 goto do_sigsegv;
68 } else {
69 if (__copy_from_user(&set, &ucp->uc_sigmask, sizeof(sigset_t)))
70 goto do_sigsegv;
71 }
72 set_current_blocked(&set);
73 }
74 if (test_thread_flag(TIF_32BIT)) {
75 pc &= 0xffffffff;
76 npc &= 0xffffffff;
77 }
78 regs->tpc = pc;
79 regs->tnpc = npc;
80 err |= __get_user(regs->y, &((*grp)[MC_Y]));
81 err |= __get_user(tstate, &((*grp)[MC_TSTATE]));
82 regs->tstate &= ~(TSTATE_ASI | TSTATE_ICC | TSTATE_XCC);
83 regs->tstate |= (tstate & (TSTATE_ASI | TSTATE_ICC | TSTATE_XCC));
84 err |= __get_user(regs->u_regs[UREG_G1], (&(*grp)[MC_G1]));
85 err |= __get_user(regs->u_regs[UREG_G2], (&(*grp)[MC_G2]));
86 err |= __get_user(regs->u_regs[UREG_G3], (&(*grp)[MC_G3]));
87 err |= __get_user(regs->u_regs[UREG_G4], (&(*grp)[MC_G4]));
88 err |= __get_user(regs->u_regs[UREG_G5], (&(*grp)[MC_G5]));
89 err |= __get_user(regs->u_regs[UREG_G6], (&(*grp)[MC_G6]));
90
91 /* Skip %g7 as that's the thread register in userspace. */
92
93 err |= __get_user(regs->u_regs[UREG_I0], (&(*grp)[MC_O0]));
94 err |= __get_user(regs->u_regs[UREG_I1], (&(*grp)[MC_O1]));
95 err |= __get_user(regs->u_regs[UREG_I2], (&(*grp)[MC_O2]));
96 err |= __get_user(regs->u_regs[UREG_I3], (&(*grp)[MC_O3]));
97 err |= __get_user(regs->u_regs[UREG_I4], (&(*grp)[MC_O4]));
98 err |= __get_user(regs->u_regs[UREG_I5], (&(*grp)[MC_O5]));
99 err |= __get_user(regs->u_regs[UREG_I6], (&(*grp)[MC_O6]));
100 err |= __get_user(regs->u_regs[UREG_I7], (&(*grp)[MC_O7]));
101
102 err |= __get_user(fp, &(ucp->uc_mcontext.mc_fp));
103 err |= __get_user(i7, &(ucp->uc_mcontext.mc_i7));
104 err |= __put_user(fp,
105 (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[6])));
106 err |= __put_user(i7,
107 (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[7])));
108
109 err |= __get_user(fenab, &(ucp->uc_mcontext.mc_fpregs.mcfpu_enab));
110 if (fenab) {
111 unsigned long *fpregs = current_thread_info()->fpregs;
112 unsigned long fprs;
113
114 fprs_write(0);
115 err |= __get_user(fprs, &(ucp->uc_mcontext.mc_fpregs.mcfpu_fprs));
116 if (fprs & FPRS_DL)
117 err |= copy_from_user(fpregs,
118 &(ucp->uc_mcontext.mc_fpregs.mcfpu_fregs),
119 (sizeof(unsigned int) * 32));
120 if (fprs & FPRS_DU)
121 err |= copy_from_user(fpregs+16,
122 ((unsigned long __user *)&(ucp->uc_mcontext.mc_fpregs.mcfpu_fregs))+16,
123 (sizeof(unsigned int) * 32));
124 err |= __get_user(current_thread_info()->xfsr[0],
125 &(ucp->uc_mcontext.mc_fpregs.mcfpu_fsr));
126 err |= __get_user(current_thread_info()->gsr[0],
127 &(ucp->uc_mcontext.mc_fpregs.mcfpu_gsr));
128 regs->tstate &= ~TSTATE_PEF;
129 }
130 if (err)
131 goto do_sigsegv;
132
133 return;
134do_sigsegv:
135 force_sig(SIGSEGV, current);
136}
137
138asmlinkage void sparc64_get_context(struct pt_regs *regs)
139{
140 struct ucontext __user *ucp = (struct ucontext __user *)
141 regs->u_regs[UREG_I0];
142 mc_gregset_t __user *grp;
143 mcontext_t __user *mcp;
144 unsigned long fp, i7;
145 unsigned char fenab;
146 int err;
147
148 synchronize_user_stack();
149 if (get_thread_wsaved() || clear_user(ucp, sizeof(*ucp)))
150 goto do_sigsegv;
151
152#if 1
153 fenab = 0; /* IMO get_context is like any other system call, thus modifies FPU state -jj */
154#else
155 fenab = (current_thread_info()->fpsaved[0] & FPRS_FEF);
156#endif
157
158 mcp = &ucp->uc_mcontext;
159 grp = &mcp->mc_gregs;
160
161 /* Skip over the trap instruction, first. */
162 if (test_thread_flag(TIF_32BIT)) {
163 regs->tpc = (regs->tnpc & 0xffffffff);
164 regs->tnpc = (regs->tnpc + 4) & 0xffffffff;
165 } else {
166 regs->tpc = regs->tnpc;
167 regs->tnpc += 4;
168 }
169 err = 0;
170 if (_NSIG_WORDS == 1)
171 err |= __put_user(current->blocked.sig[0],
172 (unsigned long __user *)&ucp->uc_sigmask);
173 else
174 err |= __copy_to_user(&ucp->uc_sigmask, ¤t->blocked,
175 sizeof(sigset_t));
176
177 err |= __put_user(regs->tstate, &((*grp)[MC_TSTATE]));
178 err |= __put_user(regs->tpc, &((*grp)[MC_PC]));
179 err |= __put_user(regs->tnpc, &((*grp)[MC_NPC]));
180 err |= __put_user(regs->y, &((*grp)[MC_Y]));
181 err |= __put_user(regs->u_regs[UREG_G1], &((*grp)[MC_G1]));
182 err |= __put_user(regs->u_regs[UREG_G2], &((*grp)[MC_G2]));
183 err |= __put_user(regs->u_regs[UREG_G3], &((*grp)[MC_G3]));
184 err |= __put_user(regs->u_regs[UREG_G4], &((*grp)[MC_G4]));
185 err |= __put_user(regs->u_regs[UREG_G5], &((*grp)[MC_G5]));
186 err |= __put_user(regs->u_regs[UREG_G6], &((*grp)[MC_G6]));
187 err |= __put_user(regs->u_regs[UREG_G7], &((*grp)[MC_G7]));
188 err |= __put_user(regs->u_regs[UREG_I0], &((*grp)[MC_O0]));
189 err |= __put_user(regs->u_regs[UREG_I1], &((*grp)[MC_O1]));
190 err |= __put_user(regs->u_regs[UREG_I2], &((*grp)[MC_O2]));
191 err |= __put_user(regs->u_regs[UREG_I3], &((*grp)[MC_O3]));
192 err |= __put_user(regs->u_regs[UREG_I4], &((*grp)[MC_O4]));
193 err |= __put_user(regs->u_regs[UREG_I5], &((*grp)[MC_O5]));
194 err |= __put_user(regs->u_regs[UREG_I6], &((*grp)[MC_O6]));
195 err |= __put_user(regs->u_regs[UREG_I7], &((*grp)[MC_O7]));
196
197 err |= __get_user(fp,
198 (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[6])));
199 err |= __get_user(i7,
200 (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[7])));
201 err |= __put_user(fp, &(mcp->mc_fp));
202 err |= __put_user(i7, &(mcp->mc_i7));
203
204 err |= __put_user(fenab, &(mcp->mc_fpregs.mcfpu_enab));
205 if (fenab) {
206 unsigned long *fpregs = current_thread_info()->fpregs;
207 unsigned long fprs;
208
209 fprs = current_thread_info()->fpsaved[0];
210 if (fprs & FPRS_DL)
211 err |= copy_to_user(&(mcp->mc_fpregs.mcfpu_fregs), fpregs,
212 (sizeof(unsigned int) * 32));
213 if (fprs & FPRS_DU)
214 err |= copy_to_user(
215 ((unsigned long __user *)&(mcp->mc_fpregs.mcfpu_fregs))+16, fpregs+16,
216 (sizeof(unsigned int) * 32));
217 err |= __put_user(current_thread_info()->xfsr[0], &(mcp->mc_fpregs.mcfpu_fsr));
218 err |= __put_user(current_thread_info()->gsr[0], &(mcp->mc_fpregs.mcfpu_gsr));
219 err |= __put_user(fprs, &(mcp->mc_fpregs.mcfpu_fprs));
220 }
221 if (err)
222 goto do_sigsegv;
223
224 return;
225do_sigsegv:
226 force_sig(SIGSEGV, current);
227}
228
229struct rt_signal_frame {
230 struct sparc_stackf ss;
231 siginfo_t info;
232 struct pt_regs regs;
233 __siginfo_fpu_t __user *fpu_save;
234 stack_t stack;
235 sigset_t mask;
236 __siginfo_rwin_t *rwin_save;
237};
238
239static long _sigpause_common(old_sigset_t set)
240{
241 sigset_t blocked;
242 siginitset(&blocked, set);
243 return sigsuspend(&blocked);
244}
245
246asmlinkage long sys_sigpause(unsigned int set)
247{
248 return _sigpause_common(set);
249}
250
251asmlinkage long sys_sigsuspend(old_sigset_t set)
252{
253 return _sigpause_common(set);
254}
255
256void do_rt_sigreturn(struct pt_regs *regs)
257{
258 struct rt_signal_frame __user *sf;
259 unsigned long tpc, tnpc, tstate;
260 __siginfo_fpu_t __user *fpu_save;
261 __siginfo_rwin_t __user *rwin_save;
262 sigset_t set;
263 int err;
264
265 /* Always make any pending restarted system calls return -EINTR */
266 current_thread_info()->restart_block.fn = do_no_restart_syscall;
267
268 synchronize_user_stack ();
269 sf = (struct rt_signal_frame __user *)
270 (regs->u_regs [UREG_FP] + STACK_BIAS);
271
272 /* 1. Make sure we are not getting garbage from the user */
273 if (((unsigned long) sf) & 3)
274 goto segv;
275
276 err = get_user(tpc, &sf->regs.tpc);
277 err |= __get_user(tnpc, &sf->regs.tnpc);
278 if (test_thread_flag(TIF_32BIT)) {
279 tpc &= 0xffffffff;
280 tnpc &= 0xffffffff;
281 }
282 err |= ((tpc | tnpc) & 3);
283
284 /* 2. Restore the state */
285 err |= __get_user(regs->y, &sf->regs.y);
286 err |= __get_user(tstate, &sf->regs.tstate);
287 err |= copy_from_user(regs->u_regs, sf->regs.u_regs, sizeof(regs->u_regs));
288
289 /* User can only change condition codes and %asi in %tstate. */
290 regs->tstate &= ~(TSTATE_ASI | TSTATE_ICC | TSTATE_XCC);
291 regs->tstate |= (tstate & (TSTATE_ASI | TSTATE_ICC | TSTATE_XCC));
292
293 err |= __get_user(fpu_save, &sf->fpu_save);
294 if (!err && fpu_save)
295 err |= restore_fpu_state(regs, fpu_save);
296
297 err |= __copy_from_user(&set, &sf->mask, sizeof(sigset_t));
298 err |= do_sigaltstack(&sf->stack, NULL, (unsigned long)sf);
299
300 if (err)
301 goto segv;
302
303 err |= __get_user(rwin_save, &sf->rwin_save);
304 if (!err && rwin_save) {
305 if (restore_rwin_state(rwin_save))
306 goto segv;
307 }
308
309 regs->tpc = tpc;
310 regs->tnpc = tnpc;
311
312 /* Prevent syscall restart. */
313 pt_regs_clear_syscall(regs);
314
315 set_current_blocked(&set);
316 return;
317segv:
318 force_sig(SIGSEGV, current);
319}
320
321/* Checks if the fp is valid */
322static int invalid_frame_pointer(void __user *fp)
323{
324 if (((unsigned long) fp) & 15)
325 return 1;
326 return 0;
327}
328
329static inline void __user *get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, unsigned long framesize)
330{
331 unsigned long sp = regs->u_regs[UREG_FP] + STACK_BIAS;
332
333 /*
334 * If we are on the alternate signal stack and would overflow it, don't.
335 * Return an always-bogus address instead so we will die with SIGSEGV.
336 */
337 if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize)))
338 return (void __user *) -1L;
339
340 /* This is the X/Open sanctioned signal stack switching. */
341 if (ka->sa.sa_flags & SA_ONSTACK) {
342 if (sas_ss_flags(sp) == 0)
343 sp = current->sas_ss_sp + current->sas_ss_size;
344 }
345
346 sp -= framesize;
347
348 /* Always align the stack frame. This handles two cases. First,
349 * sigaltstack need not be mindful of platform specific stack
350 * alignment. Second, if we took this signal because the stack
351 * is not aligned properly, we'd like to take the signal cleanly
352 * and report that.
353 */
354 sp &= ~15UL;
355
356 return (void __user *) sp;
357}
358
359static inline int
360setup_rt_frame(struct k_sigaction *ka, struct pt_regs *regs,
361 int signo, sigset_t *oldset, siginfo_t *info)
362{
363 struct rt_signal_frame __user *sf;
364 int wsaved, err, sf_size;
365 void __user *tail;
366
367 /* 1. Make sure everything is clean */
368 synchronize_user_stack();
369 save_and_clear_fpu();
370
371 wsaved = get_thread_wsaved();
372
373 sf_size = sizeof(struct rt_signal_frame);
374 if (current_thread_info()->fpsaved[0] & FPRS_FEF)
375 sf_size += sizeof(__siginfo_fpu_t);
376 if (wsaved)
377 sf_size += sizeof(__siginfo_rwin_t);
378 sf = (struct rt_signal_frame __user *)
379 get_sigframe(ka, regs, sf_size);
380
381 if (invalid_frame_pointer (sf))
382 goto sigill;
383
384 tail = (sf + 1);
385
386 /* 2. Save the current process state */
387 err = copy_to_user(&sf->regs, regs, sizeof (*regs));
388
389 if (current_thread_info()->fpsaved[0] & FPRS_FEF) {
390 __siginfo_fpu_t __user *fpu_save = tail;
391 tail += sizeof(__siginfo_fpu_t);
392 err |= save_fpu_state(regs, fpu_save);
393 err |= __put_user((u64)fpu_save, &sf->fpu_save);
394 } else {
395 err |= __put_user(0, &sf->fpu_save);
396 }
397 if (wsaved) {
398 __siginfo_rwin_t __user *rwin_save = tail;
399 tail += sizeof(__siginfo_rwin_t);
400 err |= save_rwin_state(wsaved, rwin_save);
401 err |= __put_user((u64)rwin_save, &sf->rwin_save);
402 set_thread_wsaved(0);
403 } else {
404 err |= __put_user(0, &sf->rwin_save);
405 }
406
407 /* Setup sigaltstack */
408 err |= __put_user(current->sas_ss_sp, &sf->stack.ss_sp);
409 err |= __put_user(sas_ss_flags(regs->u_regs[UREG_FP]), &sf->stack.ss_flags);
410 err |= __put_user(current->sas_ss_size, &sf->stack.ss_size);
411
412 err |= copy_to_user(&sf->mask, oldset, sizeof(sigset_t));
413
414 if (!wsaved) {
415 err |= copy_in_user((u64 __user *)sf,
416 (u64 __user *)(regs->u_regs[UREG_FP] +
417 STACK_BIAS),
418 sizeof(struct reg_window));
419 } else {
420 struct reg_window *rp;
421
422 rp = ¤t_thread_info()->reg_window[wsaved - 1];
423 err |= copy_to_user(sf, rp, sizeof(struct reg_window));
424 }
425 if (info)
426 err |= copy_siginfo_to_user(&sf->info, info);
427 else {
428 err |= __put_user(signo, &sf->info.si_signo);
429 err |= __put_user(SI_NOINFO, &sf->info.si_code);
430 }
431 if (err)
432 goto sigsegv;
433
434 /* 3. signal handler back-trampoline and parameters */
435 regs->u_regs[UREG_FP] = ((unsigned long) sf) - STACK_BIAS;
436 regs->u_regs[UREG_I0] = signo;
437 regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
438
439 /* The sigcontext is passed in this way because of how it
440 * is defined in GLIBC's /usr/include/bits/sigcontext.h
441 * for sparc64. It includes the 128 bytes of siginfo_t.
442 */
443 regs->u_regs[UREG_I2] = (unsigned long) &sf->info;
444
445 /* 5. signal handler */
446 regs->tpc = (unsigned long) ka->sa.sa_handler;
447 regs->tnpc = (regs->tpc + 4);
448 if (test_thread_flag(TIF_32BIT)) {
449 regs->tpc &= 0xffffffff;
450 regs->tnpc &= 0xffffffff;
451 }
452 /* 4. return to kernel instructions */
453 regs->u_regs[UREG_I7] = (unsigned long)ka->ka_restorer;
454 return 0;
455
456sigill:
457 do_exit(SIGILL);
458 return -EINVAL;
459
460sigsegv:
461 force_sigsegv(signo, current);
462 return -EFAULT;
463}
464
465static inline void handle_signal(unsigned long signr, struct k_sigaction *ka,
466 siginfo_t *info,
467 sigset_t *oldset, struct pt_regs *regs)
468{
469 int err;
470
471 err = setup_rt_frame(ka, regs, signr, oldset,
472 (ka->sa.sa_flags & SA_SIGINFO) ? info : NULL);
473 if (err)
474 return;
475
476 signal_delivered(signr, info, ka, regs, 0);
477}
478
479static inline void syscall_restart(unsigned long orig_i0, struct pt_regs *regs,
480 struct sigaction *sa)
481{
482 switch (regs->u_regs[UREG_I0]) {
483 case ERESTART_RESTARTBLOCK:
484 case ERESTARTNOHAND:
485 no_system_call_restart:
486 regs->u_regs[UREG_I0] = EINTR;
487 regs->tstate |= (TSTATE_ICARRY|TSTATE_XCARRY);
488 break;
489 case ERESTARTSYS:
490 if (!(sa->sa_flags & SA_RESTART))
491 goto no_system_call_restart;
492 /* fallthrough */
493 case ERESTARTNOINTR:
494 regs->u_regs[UREG_I0] = orig_i0;
495 regs->tpc -= 4;
496 regs->tnpc -= 4;
497 }
498}
499
500/* Note that 'init' is a special process: it doesn't get signals it doesn't
501 * want to handle. Thus you cannot kill init even with a SIGKILL even by
502 * mistake.
503 */
504static void do_signal(struct pt_regs *regs, unsigned long orig_i0)
505{
506 struct k_sigaction ka;
507 int restart_syscall;
508 sigset_t *oldset = sigmask_to_save();
509 siginfo_t info;
510 int signr;
511
512 /* It's a lot of work and synchronization to add a new ptrace
513 * register for GDB to save and restore in order to get
514 * orig_i0 correct for syscall restarts when debugging.
515 *
516 * Although it should be the case that most of the global
517 * registers are volatile across a system call, glibc already
518 * depends upon that fact that we preserve them. So we can't
519 * just use any global register to save away the orig_i0 value.
520 *
521 * In particular %g2, %g3, %g4, and %g5 are all assumed to be
522 * preserved across a system call trap by various pieces of
523 * code in glibc.
524 *
525 * %g7 is used as the "thread register". %g6 is not used in
526 * any fixed manner. %g6 is used as a scratch register and
527 * a compiler temporary, but it's value is never used across
528 * a system call. Therefore %g6 is usable for orig_i0 storage.
529 */
530 if (pt_regs_is_syscall(regs) &&
531 (regs->tstate & (TSTATE_XCARRY | TSTATE_ICARRY)))
532 regs->u_regs[UREG_G6] = orig_i0;
533
534#ifdef CONFIG_COMPAT
535 if (test_thread_flag(TIF_32BIT)) {
536 extern void do_signal32(sigset_t *, struct pt_regs *);
537 do_signal32(oldset, regs);
538 return;
539 }
540#endif
541
542 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
543
544 restart_syscall = 0;
545 if (pt_regs_is_syscall(regs) &&
546 (regs->tstate & (TSTATE_XCARRY | TSTATE_ICARRY))) {
547 restart_syscall = 1;
548 orig_i0 = regs->u_regs[UREG_G6];
549 }
550
551 if (signr > 0) {
552 if (restart_syscall)
553 syscall_restart(orig_i0, regs, &ka.sa);
554 handle_signal(signr, &ka, &info, oldset, regs);
555 return;
556 }
557 if (restart_syscall &&
558 (regs->u_regs[UREG_I0] == ERESTARTNOHAND ||
559 regs->u_regs[UREG_I0] == ERESTARTSYS ||
560 regs->u_regs[UREG_I0] == ERESTARTNOINTR)) {
561 /* replay the system call when we are done */
562 regs->u_regs[UREG_I0] = orig_i0;
563 regs->tpc -= 4;
564 regs->tnpc -= 4;
565 pt_regs_clear_syscall(regs);
566 }
567 if (restart_syscall &&
568 regs->u_regs[UREG_I0] == ERESTART_RESTARTBLOCK) {
569 regs->u_regs[UREG_G1] = __NR_restart_syscall;
570 regs->tpc -= 4;
571 regs->tnpc -= 4;
572 pt_regs_clear_syscall(regs);
573 }
574
575 /* If there's no signal to deliver, we just put the saved sigmask
576 * back
577 */
578 restore_saved_sigmask();
579}
580
581void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0, unsigned long thread_info_flags)
582{
583 if (thread_info_flags & _TIF_SIGPENDING)
584 do_signal(regs, orig_i0);
585 if (thread_info_flags & _TIF_NOTIFY_RESUME) {
586 clear_thread_flag(TIF_NOTIFY_RESUME);
587 tracehook_notify_resume(regs);
588 }
589}
590
1/*
2 * arch/sparc64/kernel/signal.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 * Copyright (C) 1995, 2008 David S. Miller (davem@davemloft.net)
6 * Copyright (C) 1996 Miguel de Icaza (miguel@nuclecu.unam.mx)
7 * Copyright (C) 1997 Eddie C. Dost (ecd@skynet.be)
8 * Copyright (C) 1997,1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
9 */
10
11#ifdef CONFIG_COMPAT
12#include <linux/compat.h> /* for compat_old_sigset_t */
13#endif
14#include <linux/sched.h>
15#include <linux/kernel.h>
16#include <linux/signal.h>
17#include <linux/errno.h>
18#include <linux/wait.h>
19#include <linux/ptrace.h>
20#include <linux/tracehook.h>
21#include <linux/unistd.h>
22#include <linux/mm.h>
23#include <linux/tty.h>
24#include <linux/binfmts.h>
25#include <linux/bitops.h>
26#include <linux/context_tracking.h>
27
28#include <linux/uaccess.h>
29#include <asm/ptrace.h>
30#include <asm/pgtable.h>
31#include <asm/fpumacro.h>
32#include <asm/uctx.h>
33#include <asm/siginfo.h>
34#include <asm/visasm.h>
35#include <asm/switch_to.h>
36#include <asm/cacheflush.h>
37
38#include "sigutil.h"
39#include "systbls.h"
40#include "kernel.h"
41#include "entry.h"
42
43/* {set, get}context() needed for 64-bit SparcLinux userland. */
44asmlinkage void sparc64_set_context(struct pt_regs *regs)
45{
46 struct ucontext __user *ucp = (struct ucontext __user *)
47 regs->u_regs[UREG_I0];
48 enum ctx_state prev_state = exception_enter();
49 mc_gregset_t __user *grp;
50 unsigned long pc, npc, tstate;
51 unsigned long fp, i7;
52 unsigned char fenab;
53 int err;
54
55 synchronize_user_stack();
56 if (get_thread_wsaved() ||
57 (((unsigned long)ucp) & (sizeof(unsigned long)-1)) ||
58 (!__access_ok(ucp, sizeof(*ucp))))
59 goto do_sigsegv;
60 grp = &ucp->uc_mcontext.mc_gregs;
61 err = __get_user(pc, &((*grp)[MC_PC]));
62 err |= __get_user(npc, &((*grp)[MC_NPC]));
63 if (err || ((pc | npc) & 3))
64 goto do_sigsegv;
65 if (regs->u_regs[UREG_I1]) {
66 sigset_t set;
67
68 if (_NSIG_WORDS == 1) {
69 if (__get_user(set.sig[0], &ucp->uc_sigmask.sig[0]))
70 goto do_sigsegv;
71 } else {
72 if (__copy_from_user(&set, &ucp->uc_sigmask, sizeof(sigset_t)))
73 goto do_sigsegv;
74 }
75 set_current_blocked(&set);
76 }
77 if (test_thread_flag(TIF_32BIT)) {
78 pc &= 0xffffffff;
79 npc &= 0xffffffff;
80 }
81 regs->tpc = pc;
82 regs->tnpc = npc;
83 err |= __get_user(regs->y, &((*grp)[MC_Y]));
84 err |= __get_user(tstate, &((*grp)[MC_TSTATE]));
85 regs->tstate &= ~(TSTATE_ASI | TSTATE_ICC | TSTATE_XCC);
86 regs->tstate |= (tstate & (TSTATE_ASI | TSTATE_ICC | TSTATE_XCC));
87 err |= __get_user(regs->u_regs[UREG_G1], (&(*grp)[MC_G1]));
88 err |= __get_user(regs->u_regs[UREG_G2], (&(*grp)[MC_G2]));
89 err |= __get_user(regs->u_regs[UREG_G3], (&(*grp)[MC_G3]));
90 err |= __get_user(regs->u_regs[UREG_G4], (&(*grp)[MC_G4]));
91 err |= __get_user(regs->u_regs[UREG_G5], (&(*grp)[MC_G5]));
92 err |= __get_user(regs->u_regs[UREG_G6], (&(*grp)[MC_G6]));
93
94 /* Skip %g7 as that's the thread register in userspace. */
95
96 err |= __get_user(regs->u_regs[UREG_I0], (&(*grp)[MC_O0]));
97 err |= __get_user(regs->u_regs[UREG_I1], (&(*grp)[MC_O1]));
98 err |= __get_user(regs->u_regs[UREG_I2], (&(*grp)[MC_O2]));
99 err |= __get_user(regs->u_regs[UREG_I3], (&(*grp)[MC_O3]));
100 err |= __get_user(regs->u_regs[UREG_I4], (&(*grp)[MC_O4]));
101 err |= __get_user(regs->u_regs[UREG_I5], (&(*grp)[MC_O5]));
102 err |= __get_user(regs->u_regs[UREG_I6], (&(*grp)[MC_O6]));
103 err |= __get_user(regs->u_regs[UREG_I7], (&(*grp)[MC_O7]));
104
105 err |= __get_user(fp, &(ucp->uc_mcontext.mc_fp));
106 err |= __get_user(i7, &(ucp->uc_mcontext.mc_i7));
107 err |= __put_user(fp,
108 (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[6])));
109 err |= __put_user(i7,
110 (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[7])));
111
112 err |= __get_user(fenab, &(ucp->uc_mcontext.mc_fpregs.mcfpu_enab));
113 if (fenab) {
114 unsigned long *fpregs = current_thread_info()->fpregs;
115 unsigned long fprs;
116
117 fprs_write(0);
118 err |= __get_user(fprs, &(ucp->uc_mcontext.mc_fpregs.mcfpu_fprs));
119 if (fprs & FPRS_DL)
120 err |= copy_from_user(fpregs,
121 &(ucp->uc_mcontext.mc_fpregs.mcfpu_fregs),
122 (sizeof(unsigned int) * 32));
123 if (fprs & FPRS_DU)
124 err |= copy_from_user(fpregs+16,
125 ((unsigned long __user *)&(ucp->uc_mcontext.mc_fpregs.mcfpu_fregs))+16,
126 (sizeof(unsigned int) * 32));
127 err |= __get_user(current_thread_info()->xfsr[0],
128 &(ucp->uc_mcontext.mc_fpregs.mcfpu_fsr));
129 err |= __get_user(current_thread_info()->gsr[0],
130 &(ucp->uc_mcontext.mc_fpregs.mcfpu_gsr));
131 regs->tstate &= ~TSTATE_PEF;
132 }
133 if (err)
134 goto do_sigsegv;
135out:
136 exception_exit(prev_state);
137 return;
138do_sigsegv:
139 force_sig(SIGSEGV, current);
140 goto out;
141}
142
143asmlinkage void sparc64_get_context(struct pt_regs *regs)
144{
145 struct ucontext __user *ucp = (struct ucontext __user *)
146 regs->u_regs[UREG_I0];
147 enum ctx_state prev_state = exception_enter();
148 mc_gregset_t __user *grp;
149 mcontext_t __user *mcp;
150 unsigned long fp, i7;
151 unsigned char fenab;
152 int err;
153
154 synchronize_user_stack();
155 if (get_thread_wsaved() || clear_user(ucp, sizeof(*ucp)))
156 goto do_sigsegv;
157
158#if 1
159 fenab = 0; /* IMO get_context is like any other system call, thus modifies FPU state -jj */
160#else
161 fenab = (current_thread_info()->fpsaved[0] & FPRS_FEF);
162#endif
163
164 mcp = &ucp->uc_mcontext;
165 grp = &mcp->mc_gregs;
166
167 /* Skip over the trap instruction, first. */
168 if (test_thread_flag(TIF_32BIT)) {
169 regs->tpc = (regs->tnpc & 0xffffffff);
170 regs->tnpc = (regs->tnpc + 4) & 0xffffffff;
171 } else {
172 regs->tpc = regs->tnpc;
173 regs->tnpc += 4;
174 }
175 err = 0;
176 if (_NSIG_WORDS == 1)
177 err |= __put_user(current->blocked.sig[0],
178 (unsigned long __user *)&ucp->uc_sigmask);
179 else
180 err |= __copy_to_user(&ucp->uc_sigmask, ¤t->blocked,
181 sizeof(sigset_t));
182
183 err |= __put_user(regs->tstate, &((*grp)[MC_TSTATE]));
184 err |= __put_user(regs->tpc, &((*grp)[MC_PC]));
185 err |= __put_user(regs->tnpc, &((*grp)[MC_NPC]));
186 err |= __put_user(regs->y, &((*grp)[MC_Y]));
187 err |= __put_user(regs->u_regs[UREG_G1], &((*grp)[MC_G1]));
188 err |= __put_user(regs->u_regs[UREG_G2], &((*grp)[MC_G2]));
189 err |= __put_user(regs->u_regs[UREG_G3], &((*grp)[MC_G3]));
190 err |= __put_user(regs->u_regs[UREG_G4], &((*grp)[MC_G4]));
191 err |= __put_user(regs->u_regs[UREG_G5], &((*grp)[MC_G5]));
192 err |= __put_user(regs->u_regs[UREG_G6], &((*grp)[MC_G6]));
193 err |= __put_user(regs->u_regs[UREG_G7], &((*grp)[MC_G7]));
194 err |= __put_user(regs->u_regs[UREG_I0], &((*grp)[MC_O0]));
195 err |= __put_user(regs->u_regs[UREG_I1], &((*grp)[MC_O1]));
196 err |= __put_user(regs->u_regs[UREG_I2], &((*grp)[MC_O2]));
197 err |= __put_user(regs->u_regs[UREG_I3], &((*grp)[MC_O3]));
198 err |= __put_user(regs->u_regs[UREG_I4], &((*grp)[MC_O4]));
199 err |= __put_user(regs->u_regs[UREG_I5], &((*grp)[MC_O5]));
200 err |= __put_user(regs->u_regs[UREG_I6], &((*grp)[MC_O6]));
201 err |= __put_user(regs->u_regs[UREG_I7], &((*grp)[MC_O7]));
202
203 err |= __get_user(fp,
204 (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[6])));
205 err |= __get_user(i7,
206 (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[7])));
207 err |= __put_user(fp, &(mcp->mc_fp));
208 err |= __put_user(i7, &(mcp->mc_i7));
209
210 err |= __put_user(fenab, &(mcp->mc_fpregs.mcfpu_enab));
211 if (fenab) {
212 unsigned long *fpregs = current_thread_info()->fpregs;
213 unsigned long fprs;
214
215 fprs = current_thread_info()->fpsaved[0];
216 if (fprs & FPRS_DL)
217 err |= copy_to_user(&(mcp->mc_fpregs.mcfpu_fregs), fpregs,
218 (sizeof(unsigned int) * 32));
219 if (fprs & FPRS_DU)
220 err |= copy_to_user(
221 ((unsigned long __user *)&(mcp->mc_fpregs.mcfpu_fregs))+16, fpregs+16,
222 (sizeof(unsigned int) * 32));
223 err |= __put_user(current_thread_info()->xfsr[0], &(mcp->mc_fpregs.mcfpu_fsr));
224 err |= __put_user(current_thread_info()->gsr[0], &(mcp->mc_fpregs.mcfpu_gsr));
225 err |= __put_user(fprs, &(mcp->mc_fpregs.mcfpu_fprs));
226 }
227 if (err)
228 goto do_sigsegv;
229out:
230 exception_exit(prev_state);
231 return;
232do_sigsegv:
233 force_sig(SIGSEGV, current);
234 goto out;
235}
236
237/* Checks if the fp is valid. We always build rt signal frames which
238 * are 16-byte aligned, therefore we can always enforce that the
239 * restore frame has that property as well.
240 */
241static bool invalid_frame_pointer(void __user *fp)
242{
243 if (((unsigned long) fp) & 15)
244 return true;
245 return false;
246}
247
248struct rt_signal_frame {
249 struct sparc_stackf ss;
250 siginfo_t info;
251 struct pt_regs regs;
252 __siginfo_fpu_t __user *fpu_save;
253 stack_t stack;
254 sigset_t mask;
255 __siginfo_rwin_t *rwin_save;
256};
257
258void do_rt_sigreturn(struct pt_regs *regs)
259{
260 unsigned long tpc, tnpc, tstate, ufp;
261 struct rt_signal_frame __user *sf;
262 __siginfo_fpu_t __user *fpu_save;
263 __siginfo_rwin_t __user *rwin_save;
264 sigset_t set;
265 int err;
266
267 /* Always make any pending restarted system calls return -EINTR */
268 current->restart_block.fn = do_no_restart_syscall;
269
270 synchronize_user_stack ();
271 sf = (struct rt_signal_frame __user *)
272 (regs->u_regs [UREG_FP] + STACK_BIAS);
273
274 /* 1. Make sure we are not getting garbage from the user */
275 if (invalid_frame_pointer(sf))
276 goto segv;
277
278 if (get_user(ufp, &sf->regs.u_regs[UREG_FP]))
279 goto segv;
280
281 if ((ufp + STACK_BIAS) & 0x7)
282 goto segv;
283
284 err = __get_user(tpc, &sf->regs.tpc);
285 err |= __get_user(tnpc, &sf->regs.tnpc);
286 if (test_thread_flag(TIF_32BIT)) {
287 tpc &= 0xffffffff;
288 tnpc &= 0xffffffff;
289 }
290 err |= ((tpc | tnpc) & 3);
291
292 /* 2. Restore the state */
293 err |= __get_user(regs->y, &sf->regs.y);
294 err |= __get_user(tstate, &sf->regs.tstate);
295 err |= copy_from_user(regs->u_regs, sf->regs.u_regs, sizeof(regs->u_regs));
296
297 /* User can only change condition codes and %asi in %tstate. */
298 regs->tstate &= ~(TSTATE_ASI | TSTATE_ICC | TSTATE_XCC);
299 regs->tstate |= (tstate & (TSTATE_ASI | TSTATE_ICC | TSTATE_XCC));
300
301 err |= __get_user(fpu_save, &sf->fpu_save);
302 if (!err && fpu_save)
303 err |= restore_fpu_state(regs, fpu_save);
304
305 err |= __copy_from_user(&set, &sf->mask, sizeof(sigset_t));
306 err |= restore_altstack(&sf->stack);
307 if (err)
308 goto segv;
309
310 err |= __get_user(rwin_save, &sf->rwin_save);
311 if (!err && rwin_save) {
312 if (restore_rwin_state(rwin_save))
313 goto segv;
314 }
315
316 regs->tpc = tpc;
317 regs->tnpc = tnpc;
318
319 /* Prevent syscall restart. */
320 pt_regs_clear_syscall(regs);
321
322 set_current_blocked(&set);
323 return;
324segv:
325 force_sig(SIGSEGV, current);
326}
327
328static inline void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs, unsigned long framesize)
329{
330 unsigned long sp = regs->u_regs[UREG_FP] + STACK_BIAS;
331
332 /*
333 * If we are on the alternate signal stack and would overflow it, don't.
334 * Return an always-bogus address instead so we will die with SIGSEGV.
335 */
336 if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize)))
337 return (void __user *) -1L;
338
339 /* This is the X/Open sanctioned signal stack switching. */
340 sp = sigsp(sp, ksig) - framesize;
341
342 /* Always align the stack frame. This handles two cases. First,
343 * sigaltstack need not be mindful of platform specific stack
344 * alignment. Second, if we took this signal because the stack
345 * is not aligned properly, we'd like to take the signal cleanly
346 * and report that.
347 */
348 sp &= ~15UL;
349
350 return (void __user *) sp;
351}
352
353static inline int
354setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
355{
356 struct rt_signal_frame __user *sf;
357 int wsaved, err, sf_size;
358 void __user *tail;
359
360 /* 1. Make sure everything is clean */
361 synchronize_user_stack();
362 save_and_clear_fpu();
363
364 wsaved = get_thread_wsaved();
365
366 sf_size = sizeof(struct rt_signal_frame);
367 if (current_thread_info()->fpsaved[0] & FPRS_FEF)
368 sf_size += sizeof(__siginfo_fpu_t);
369 if (wsaved)
370 sf_size += sizeof(__siginfo_rwin_t);
371 sf = (struct rt_signal_frame __user *)
372 get_sigframe(ksig, regs, sf_size);
373
374 if (invalid_frame_pointer (sf)) {
375 do_exit(SIGILL); /* won't return, actually */
376 return -EINVAL;
377 }
378
379 tail = (sf + 1);
380
381 /* 2. Save the current process state */
382 err = copy_to_user(&sf->regs, regs, sizeof (*regs));
383
384 if (current_thread_info()->fpsaved[0] & FPRS_FEF) {
385 __siginfo_fpu_t __user *fpu_save = tail;
386 tail += sizeof(__siginfo_fpu_t);
387 err |= save_fpu_state(regs, fpu_save);
388 err |= __put_user((u64)fpu_save, &sf->fpu_save);
389 } else {
390 err |= __put_user(0, &sf->fpu_save);
391 }
392 if (wsaved) {
393 __siginfo_rwin_t __user *rwin_save = tail;
394 tail += sizeof(__siginfo_rwin_t);
395 err |= save_rwin_state(wsaved, rwin_save);
396 err |= __put_user((u64)rwin_save, &sf->rwin_save);
397 set_thread_wsaved(0);
398 } else {
399 err |= __put_user(0, &sf->rwin_save);
400 }
401
402 /* Setup sigaltstack */
403 err |= __save_altstack(&sf->stack, regs->u_regs[UREG_FP]);
404
405 err |= copy_to_user(&sf->mask, sigmask_to_save(), sizeof(sigset_t));
406
407 if (!wsaved) {
408 err |= copy_in_user((u64 __user *)sf,
409 (u64 __user *)(regs->u_regs[UREG_FP] +
410 STACK_BIAS),
411 sizeof(struct reg_window));
412 } else {
413 struct reg_window *rp;
414
415 rp = ¤t_thread_info()->reg_window[wsaved - 1];
416 err |= copy_to_user(sf, rp, sizeof(struct reg_window));
417 }
418 if (ksig->ka.sa.sa_flags & SA_SIGINFO)
419 err |= copy_siginfo_to_user(&sf->info, &ksig->info);
420 else {
421 err |= __put_user(ksig->sig, &sf->info.si_signo);
422 err |= __put_user(SI_NOINFO, &sf->info.si_code);
423 }
424 if (err)
425 return err;
426
427 /* 3. signal handler back-trampoline and parameters */
428 regs->u_regs[UREG_FP] = ((unsigned long) sf) - STACK_BIAS;
429 regs->u_regs[UREG_I0] = ksig->sig;
430 regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
431
432 /* The sigcontext is passed in this way because of how it
433 * is defined in GLIBC's /usr/include/bits/sigcontext.h
434 * for sparc64. It includes the 128 bytes of siginfo_t.
435 */
436 regs->u_regs[UREG_I2] = (unsigned long) &sf->info;
437
438 /* 5. signal handler */
439 regs->tpc = (unsigned long) ksig->ka.sa.sa_handler;
440 regs->tnpc = (regs->tpc + 4);
441 if (test_thread_flag(TIF_32BIT)) {
442 regs->tpc &= 0xffffffff;
443 regs->tnpc &= 0xffffffff;
444 }
445 /* 4. return to kernel instructions */
446 regs->u_regs[UREG_I7] = (unsigned long)ksig->ka.ka_restorer;
447 return 0;
448}
449
450static inline void syscall_restart(unsigned long orig_i0, struct pt_regs *regs,
451 struct sigaction *sa)
452{
453 switch (regs->u_regs[UREG_I0]) {
454 case ERESTART_RESTARTBLOCK:
455 case ERESTARTNOHAND:
456 no_system_call_restart:
457 regs->u_regs[UREG_I0] = EINTR;
458 regs->tstate |= (TSTATE_ICARRY|TSTATE_XCARRY);
459 break;
460 case ERESTARTSYS:
461 if (!(sa->sa_flags & SA_RESTART))
462 goto no_system_call_restart;
463 /* fallthrough */
464 case ERESTARTNOINTR:
465 regs->u_regs[UREG_I0] = orig_i0;
466 regs->tpc -= 4;
467 regs->tnpc -= 4;
468 }
469}
470
471/* Note that 'init' is a special process: it doesn't get signals it doesn't
472 * want to handle. Thus you cannot kill init even with a SIGKILL even by
473 * mistake.
474 */
475static void do_signal(struct pt_regs *regs, unsigned long orig_i0)
476{
477 struct ksignal ksig;
478 int restart_syscall;
479 bool has_handler;
480
481 /* It's a lot of work and synchronization to add a new ptrace
482 * register for GDB to save and restore in order to get
483 * orig_i0 correct for syscall restarts when debugging.
484 *
485 * Although it should be the case that most of the global
486 * registers are volatile across a system call, glibc already
487 * depends upon that fact that we preserve them. So we can't
488 * just use any global register to save away the orig_i0 value.
489 *
490 * In particular %g2, %g3, %g4, and %g5 are all assumed to be
491 * preserved across a system call trap by various pieces of
492 * code in glibc.
493 *
494 * %g7 is used as the "thread register". %g6 is not used in
495 * any fixed manner. %g6 is used as a scratch register and
496 * a compiler temporary, but it's value is never used across
497 * a system call. Therefore %g6 is usable for orig_i0 storage.
498 */
499 if (pt_regs_is_syscall(regs) &&
500 (regs->tstate & (TSTATE_XCARRY | TSTATE_ICARRY)))
501 regs->u_regs[UREG_G6] = orig_i0;
502
503#ifdef CONFIG_COMPAT
504 if (test_thread_flag(TIF_32BIT)) {
505 do_signal32(regs);
506 return;
507 }
508#endif
509
510 has_handler = get_signal(&ksig);
511
512 restart_syscall = 0;
513 if (pt_regs_is_syscall(regs) &&
514 (regs->tstate & (TSTATE_XCARRY | TSTATE_ICARRY))) {
515 restart_syscall = 1;
516 orig_i0 = regs->u_regs[UREG_G6];
517 }
518
519 if (has_handler) {
520 if (restart_syscall)
521 syscall_restart(orig_i0, regs, &ksig.ka.sa);
522 signal_setup_done(setup_rt_frame(&ksig, regs), &ksig, 0);
523 } else {
524 if (restart_syscall) {
525 switch (regs->u_regs[UREG_I0]) {
526 case ERESTARTNOHAND:
527 case ERESTARTSYS:
528 case ERESTARTNOINTR:
529 /* replay the system call when we are done */
530 regs->u_regs[UREG_I0] = orig_i0;
531 regs->tpc -= 4;
532 regs->tnpc -= 4;
533 pt_regs_clear_syscall(regs);
534 case ERESTART_RESTARTBLOCK:
535 regs->u_regs[UREG_G1] = __NR_restart_syscall;
536 regs->tpc -= 4;
537 regs->tnpc -= 4;
538 pt_regs_clear_syscall(regs);
539 }
540 }
541 restore_saved_sigmask();
542 }
543}
544
545void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0, unsigned long thread_info_flags)
546{
547 user_exit();
548 if (thread_info_flags & _TIF_UPROBE)
549 uprobe_notify_resume(regs);
550 if (thread_info_flags & _TIF_SIGPENDING)
551 do_signal(regs, orig_i0);
552 if (thread_info_flags & _TIF_NOTIFY_RESUME) {
553 clear_thread_flag(TIF_NOTIFY_RESUME);
554 tracehook_notify_resume(regs);
555 }
556 user_enter();
557}
558