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Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
[cris-mirror.git] / arch / sparc / kernel / signal_64.c
blob48366e5eb5b266fbc48ddce4d02a6809120f92b3
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * arch/sparc64/kernel/signal.c
4 *
5 * Copyright (C) 1991, 1992 Linus Torvalds
6 * Copyright (C) 1995, 2008 David S. Miller (davem@davemloft.net)
7 * Copyright (C) 1996 Miguel de Icaza (miguel@nuclecu.unam.mx)
8 * Copyright (C) 1997 Eddie C. Dost (ecd@skynet.be)
9 * Copyright (C) 1997,1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
10 */
11
12 #include <linux/sched.h>
13 #include <linux/kernel.h>
14 #include <linux/signal.h>
15 #include <linux/errno.h>
16 #include <linux/wait.h>
17 #include <linux/ptrace.h>
18 #include <linux/tracehook.h>
19 #include <linux/unistd.h>
20 #include <linux/mm.h>
21 #include <linux/tty.h>
22 #include <linux/binfmts.h>
23 #include <linux/bitops.h>
24 #include <linux/context_tracking.h>
25
26 #include <linux/uaccess.h>
27 #include <asm/ptrace.h>
28 #include <asm/pgtable.h>
29 #include <asm/fpumacro.h>
30 #include <asm/uctx.h>
31 #include <asm/siginfo.h>
32 #include <asm/visasm.h>
33 #include <asm/switch_to.h>
34 #include <asm/cacheflush.h>
35
36 #include "sigutil.h"
37 #include "systbls.h"
38 #include "kernel.h"
39 #include "entry.h"
40
41 /* {set, get}context() needed for 64-bit SparcLinux userland. */
42 asmlinkage void sparc64_set_context(struct pt_regs *regs)
43 {
44 struct ucontext __user *ucp = (struct ucontext __user *)
45 regs->u_regs[UREG_I0];
46 enum ctx_state prev_state = exception_enter();
47 mc_gregset_t __user *grp;
48 unsigned long pc, npc, tstate;
49 unsigned long fp, i7;
50 unsigned char fenab;
51 int err;
52
53 synchronize_user_stack();
54 if (get_thread_wsaved() ||
55 (((unsigned long)ucp) & (sizeof(unsigned long)-1)) ||
56 (!__access_ok(ucp, sizeof(*ucp))))
57 goto do_sigsegv;
58 grp = &ucp->uc_mcontext.mc_gregs;
59 err = __get_user(pc, &((*grp)[MC_PC]));
60 err |= __get_user(npc, &((*grp)[MC_NPC]));
61 if (err || ((pc | npc) & 3))
62 goto do_sigsegv;
63 if (regs->u_regs[UREG_I1]) {
64 sigset_t set;
65
66 if (_NSIG_WORDS == 1) {
67 if (__get_user(set.sig[0], &ucp->uc_sigmask.sig[0]))
68 goto do_sigsegv;
69 } else {
70 if (__copy_from_user(&set, &ucp->uc_sigmask, sizeof(sigset_t)))
71 goto do_sigsegv;
72 }
73 set_current_blocked(&set);
74 }
75 if (test_thread_flag(TIF_32BIT)) {
76 pc &= 0xffffffff;
77 npc &= 0xffffffff;
78 }
79 regs->tpc = pc;
80 regs->tnpc = npc;
81 err |= __get_user(regs->y, &((*grp)[MC_Y]));
82 err |= __get_user(tstate, &((*grp)[MC_TSTATE]));
83 regs->tstate &= ~(TSTATE_ASI | TSTATE_ICC | TSTATE_XCC);
84 regs->tstate |= (tstate & (TSTATE_ASI | TSTATE_ICC | TSTATE_XCC));
85 err |= __get_user(regs->u_regs[UREG_G1], (&(*grp)[MC_G1]));
86 err |= __get_user(regs->u_regs[UREG_G2], (&(*grp)[MC_G2]));
87 err |= __get_user(regs->u_regs[UREG_G3], (&(*grp)[MC_G3]));
88 err |= __get_user(regs->u_regs[UREG_G4], (&(*grp)[MC_G4]));
89 err |= __get_user(regs->u_regs[UREG_G5], (&(*grp)[MC_G5]));
90 err |= __get_user(regs->u_regs[UREG_G6], (&(*grp)[MC_G6]));
91
92 /* Skip %g7 as that's the thread register in userspace. */
93
94 err |= __get_user(regs->u_regs[UREG_I0], (&(*grp)[MC_O0]));
95 err |= __get_user(regs->u_regs[UREG_I1], (&(*grp)[MC_O1]));
96 err |= __get_user(regs->u_regs[UREG_I2], (&(*grp)[MC_O2]));
97 err |= __get_user(regs->u_regs[UREG_I3], (&(*grp)[MC_O3]));
98 err |= __get_user(regs->u_regs[UREG_I4], (&(*grp)[MC_O4]));
99 err |= __get_user(regs->u_regs[UREG_I5], (&(*grp)[MC_O5]));
100 err |= __get_user(regs->u_regs[UREG_I6], (&(*grp)[MC_O6]));
101 err |= __get_user(regs->u_regs[UREG_I7], (&(*grp)[MC_O7]));
102
103 err |= __get_user(fp, &(ucp->uc_mcontext.mc_fp));
104 err |= __get_user(i7, &(ucp->uc_mcontext.mc_i7));
105 err |= __put_user(fp,
106 (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[6])));
107 err |= __put_user(i7,
108 (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[7])));
109
110 err |= __get_user(fenab, &(ucp->uc_mcontext.mc_fpregs.mcfpu_enab));
111 if (fenab) {
112 unsigned long *fpregs = current_thread_info()->fpregs;
113 unsigned long fprs;
114
115 fprs_write(0);
116 err |= __get_user(fprs, &(ucp->uc_mcontext.mc_fpregs.mcfpu_fprs));
117 if (fprs & FPRS_DL)
118 err |= copy_from_user(fpregs,
119 &(ucp->uc_mcontext.mc_fpregs.mcfpu_fregs),
120 (sizeof(unsigned int) * 32));
121 if (fprs & FPRS_DU)
122 err |= copy_from_user(fpregs+16,
123 ((unsigned long __user *)&(ucp->uc_mcontext.mc_fpregs.mcfpu_fregs))+16,
124 (sizeof(unsigned int) * 32));
125 err |= __get_user(current_thread_info()->xfsr[0],
126 &(ucp->uc_mcontext.mc_fpregs.mcfpu_fsr));
127 err |= __get_user(current_thread_info()->gsr[0],
128 &(ucp->uc_mcontext.mc_fpregs.mcfpu_gsr));
129 regs->tstate &= ~TSTATE_PEF;
130 }
131 if (err)
132 goto do_sigsegv;
133 out:
134 exception_exit(prev_state);
135 return;
136 do_sigsegv:
137 force_sig(SIGSEGV, current);
138 goto out;
139 }
140
141 asmlinkage void sparc64_get_context(struct pt_regs *regs)
142 {
143 struct ucontext __user *ucp = (struct ucontext __user *)
144 regs->u_regs[UREG_I0];
145 enum ctx_state prev_state = exception_enter();
146 mc_gregset_t __user *grp;
147 mcontext_t __user *mcp;
148 unsigned long fp, i7;
149 unsigned char fenab;
150 int err;
151
152 synchronize_user_stack();
153 if (get_thread_wsaved() || clear_user(ucp, sizeof(*ucp)))
154 goto do_sigsegv;
155
156 #if 1
157 fenab = 0; /* IMO get_context is like any other system call, thus modifies FPU state -jj */
158 #else
159 fenab = (current_thread_info()->fpsaved[0] & FPRS_FEF);
160 #endif
161
162 mcp = &ucp->uc_mcontext;
163 grp = &mcp->mc_gregs;
164
165 /* Skip over the trap instruction, first. */
166 if (test_thread_flag(TIF_32BIT)) {
167 regs->tpc = (regs->tnpc & 0xffffffff);
168 regs->tnpc = (regs->tnpc + 4) & 0xffffffff;
169 } else {
170 regs->tpc = regs->tnpc;
171 regs->tnpc += 4;
172 }
173 err = 0;
174 if (_NSIG_WORDS == 1)
175 err |= __put_user(current->blocked.sig[0],
176 (unsigned long __user *)&ucp->uc_sigmask);
177 else
178 err |= __copy_to_user(&ucp->uc_sigmask, &current->blocked,
179 sizeof(sigset_t));
180
181 err |= __put_user(regs->tstate, &((*grp)[MC_TSTATE]));
182 err |= __put_user(regs->tpc, &((*grp)[MC_PC]));
183 err |= __put_user(regs->tnpc, &((*grp)[MC_NPC]));
184 err |= __put_user(regs->y, &((*grp)[MC_Y]));
185 err |= __put_user(regs->u_regs[UREG_G1], &((*grp)[MC_G1]));
186 err |= __put_user(regs->u_regs[UREG_G2], &((*grp)[MC_G2]));
187 err |= __put_user(regs->u_regs[UREG_G3], &((*grp)[MC_G3]));
188 err |= __put_user(regs->u_regs[UREG_G4], &((*grp)[MC_G4]));
189 err |= __put_user(regs->u_regs[UREG_G5], &((*grp)[MC_G5]));
190 err |= __put_user(regs->u_regs[UREG_G6], &((*grp)[MC_G6]));
191 err |= __put_user(regs->u_regs[UREG_G7], &((*grp)[MC_G7]));
192 err |= __put_user(regs->u_regs[UREG_I0], &((*grp)[MC_O0]));
193 err |= __put_user(regs->u_regs[UREG_I1], &((*grp)[MC_O1]));
194 err |= __put_user(regs->u_regs[UREG_I2], &((*grp)[MC_O2]));
195 err |= __put_user(regs->u_regs[UREG_I3], &((*grp)[MC_O3]));
196 err |= __put_user(regs->u_regs[UREG_I4], &((*grp)[MC_O4]));
197 err |= __put_user(regs->u_regs[UREG_I5], &((*grp)[MC_O5]));
198 err |= __put_user(regs->u_regs[UREG_I6], &((*grp)[MC_O6]));
199 err |= __put_user(regs->u_regs[UREG_I7], &((*grp)[MC_O7]));
200
201 err |= __get_user(fp,
202 (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[6])));
203 err |= __get_user(i7,
204 (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[7])));
205 err |= __put_user(fp, &(mcp->mc_fp));
206 err |= __put_user(i7, &(mcp->mc_i7));
207
208 err |= __put_user(fenab, &(mcp->mc_fpregs.mcfpu_enab));
209 if (fenab) {
210 unsigned long *fpregs = current_thread_info()->fpregs;
211 unsigned long fprs;
212
213 fprs = current_thread_info()->fpsaved[0];
214 if (fprs & FPRS_DL)
215 err |= copy_to_user(&(mcp->mc_fpregs.mcfpu_fregs), fpregs,
216 (sizeof(unsigned int) * 32));
217 if (fprs & FPRS_DU)
218 err |= copy_to_user(
219 ((unsigned long __user *)&(mcp->mc_fpregs.mcfpu_fregs))+16, fpregs+16,
220 (sizeof(unsigned int) * 32));
221 err |= __put_user(current_thread_info()->xfsr[0], &(mcp->mc_fpregs.mcfpu_fsr));
222 err |= __put_user(current_thread_info()->gsr[0], &(mcp->mc_fpregs.mcfpu_gsr));
223 err |= __put_user(fprs, &(mcp->mc_fpregs.mcfpu_fprs));
224 }
225 if (err)
226 goto do_sigsegv;
227 out:
228 exception_exit(prev_state);
229 return;
230 do_sigsegv:
231 force_sig(SIGSEGV, current);
232 goto out;
233 }
234
235 /* Checks if the fp is valid. We always build rt signal frames which
236 * are 16-byte aligned, therefore we can always enforce that the
237 * restore frame has that property as well.
238 */
239 static bool invalid_frame_pointer(void __user *fp)
240 {
241 if (((unsigned long) fp) & 15)
242 return true;
243 return false;
244 }
245
246 struct rt_signal_frame {
247 struct sparc_stackf ss;
248 siginfo_t info;
249 struct pt_regs regs;
250 __siginfo_fpu_t __user *fpu_save;
251 stack_t stack;
252 sigset_t mask;
253 __siginfo_rwin_t *rwin_save;
254 };
255
256 void do_rt_sigreturn(struct pt_regs *regs)
257 {
258 unsigned long tpc, tnpc, tstate, ufp;
259 struct rt_signal_frame __user *sf;
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->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 (invalid_frame_pointer(sf))
274 goto segv;
275
276 if (get_user(ufp, &sf->regs.u_regs[UREG_FP]))
277 goto segv;
278
279 if ((ufp + STACK_BIAS) & 0x7)
280 goto segv;
281
282 err = __get_user(tpc, &sf->regs.tpc);
283 err |= __get_user(tnpc, &sf->regs.tnpc);
284 if (test_thread_flag(TIF_32BIT)) {
285 tpc &= 0xffffffff;
286 tnpc &= 0xffffffff;
287 }
288 err |= ((tpc | tnpc) & 3);
289
290 /* 2. Restore the state */
291 err |= __get_user(regs->y, &sf->regs.y);
292 err |= __get_user(tstate, &sf->regs.tstate);
293 err |= copy_from_user(regs->u_regs, sf->regs.u_regs, sizeof(regs->u_regs));
294
295 /* User can only change condition codes and %asi in %tstate. */
296 regs->tstate &= ~(TSTATE_ASI | TSTATE_ICC | TSTATE_XCC);
297 regs->tstate |= (tstate & (TSTATE_ASI | TSTATE_ICC | TSTATE_XCC));
298
299 err |= __get_user(fpu_save, &sf->fpu_save);
300 if (!err && fpu_save)
301 err |= restore_fpu_state(regs, fpu_save);
302
303 err |= __copy_from_user(&set, &sf->mask, sizeof(sigset_t));
304 err |= restore_altstack(&sf->stack);
305 if (err)
306 goto segv;
307
308 err |= __get_user(rwin_save, &sf->rwin_save);
309 if (!err && rwin_save) {
310 if (restore_rwin_state(rwin_save))
311 goto segv;
312 }
313
314 regs->tpc = tpc;
315 regs->tnpc = tnpc;
316
317 /* Prevent syscall restart. */
318 pt_regs_clear_syscall(regs);
319
320 set_current_blocked(&set);
321 return;
322 segv:
323 force_sig(SIGSEGV, current);
324 }
325
326 static inline void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs, unsigned long framesize)
327 {
328 unsigned long sp = regs->u_regs[UREG_FP] + STACK_BIAS;
329
330 /*
331 * If we are on the alternate signal stack and would overflow it, don't.
332 * Return an always-bogus address instead so we will die with SIGSEGV.
333 */
334 if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize)))
335 return (void __user *) -1L;
336
337 /* This is the X/Open sanctioned signal stack switching. */
338 sp = sigsp(sp, ksig) - framesize;
339
340 /* Always align the stack frame. This handles two cases. First,
341 * sigaltstack need not be mindful of platform specific stack
342 * alignment. Second, if we took this signal because the stack
343 * is not aligned properly, we'd like to take the signal cleanly
344 * and report that.
345 */
346 sp &= ~15UL;
347
348 return (void __user *) sp;
349 }
350
351 static inline int
352 setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
353 {
354 struct rt_signal_frame __user *sf;
355 int wsaved, err, sf_size;
356 void __user *tail;
357
358 /* 1. Make sure everything is clean */
359 synchronize_user_stack();
360 save_and_clear_fpu();
361
362 wsaved = get_thread_wsaved();
363
364 sf_size = sizeof(struct rt_signal_frame);
365 if (current_thread_info()->fpsaved[0] & FPRS_FEF)
366 sf_size += sizeof(__siginfo_fpu_t);
367 if (wsaved)
368 sf_size += sizeof(__siginfo_rwin_t);
369 sf = (struct rt_signal_frame __user *)
370 get_sigframe(ksig, regs, sf_size);
371
372 if (invalid_frame_pointer (sf)) {
373 do_exit(SIGILL); /* won't return, actually */
374 return -EINVAL;
375 }
376
377 tail = (sf + 1);
378
379 /* 2. Save the current process state */
380 err = copy_to_user(&sf->regs, regs, sizeof (*regs));
381
382 if (current_thread_info()->fpsaved[0] & FPRS_FEF) {
383 __siginfo_fpu_t __user *fpu_save = tail;
384 tail += sizeof(__siginfo_fpu_t);
385 err |= save_fpu_state(regs, fpu_save);
386 err |= __put_user((u64)fpu_save, &sf->fpu_save);
387 } else {
388 err |= __put_user(0, &sf->fpu_save);
389 }
390 if (wsaved) {
391 __siginfo_rwin_t __user *rwin_save = tail;
392 tail += sizeof(__siginfo_rwin_t);
393 err |= save_rwin_state(wsaved, rwin_save);
394 err |= __put_user((u64)rwin_save, &sf->rwin_save);
395 set_thread_wsaved(0);
396 } else {
397 err |= __put_user(0, &sf->rwin_save);
398 }
399
400 /* Setup sigaltstack */
401 err |= __save_altstack(&sf->stack, regs->u_regs[UREG_FP]);
402
403 err |= copy_to_user(&sf->mask, sigmask_to_save(), sizeof(sigset_t));
404
405 if (!wsaved) {
406 err |= copy_in_user((u64 __user *)sf,
407 (u64 __user *)(regs->u_regs[UREG_FP] +
408 STACK_BIAS),
409 sizeof(struct reg_window));
410 } else {
411 struct reg_window *rp;
412
413 rp = &current_thread_info()->reg_window[wsaved - 1];
414 err |= copy_to_user(sf, rp, sizeof(struct reg_window));
415 }
416 if (ksig->ka.sa.sa_flags & SA_SIGINFO)
417 err |= copy_siginfo_to_user(&sf->info, &ksig->info);
418 else {
419 err |= __put_user(ksig->sig, &sf->info.si_signo);
420 err |= __put_user(SI_NOINFO, &sf->info.si_code);
421 }
422 if (err)
423 return err;
424
425 /* 3. signal handler back-trampoline and parameters */
426 regs->u_regs[UREG_FP] = ((unsigned long) sf) - STACK_BIAS;
427 regs->u_regs[UREG_I0] = ksig->sig;
428 regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
429
430 /* The sigcontext is passed in this way because of how it
431 * is defined in GLIBC's /usr/include/bits/sigcontext.h
432 * for sparc64. It includes the 128 bytes of siginfo_t.
433 */
434 regs->u_regs[UREG_I2] = (unsigned long) &sf->info;
435
436 /* 5. signal handler */
437 regs->tpc = (unsigned long) ksig->ka.sa.sa_handler;
438 regs->tnpc = (regs->tpc + 4);
439 if (test_thread_flag(TIF_32BIT)) {
440 regs->tpc &= 0xffffffff;
441 regs->tnpc &= 0xffffffff;
442 }
443 /* 4. return to kernel instructions */
444 regs->u_regs[UREG_I7] = (unsigned long)ksig->ka.ka_restorer;
445 return 0;
446 }
447
448 static inline void syscall_restart(unsigned long orig_i0, struct pt_regs *regs,
449 struct sigaction *sa)
450 {
451 switch (regs->u_regs[UREG_I0]) {
452 case ERESTART_RESTARTBLOCK:
453 case ERESTARTNOHAND:
454 no_system_call_restart:
455 regs->u_regs[UREG_I0] = EINTR;
456 regs->tstate |= (TSTATE_ICARRY|TSTATE_XCARRY);
457 break;
458 case ERESTARTSYS:
459 if (!(sa->sa_flags & SA_RESTART))
460 goto no_system_call_restart;
461 /* fallthrough */
462 case ERESTARTNOINTR:
463 regs->u_regs[UREG_I0] = orig_i0;
464 regs->tpc -= 4;
465 regs->tnpc -= 4;
466 }
467 }
468
469 /* Note that 'init' is a special process: it doesn't get signals it doesn't
470 * want to handle. Thus you cannot kill init even with a SIGKILL even by
471 * mistake.
472 */
473 static void do_signal(struct pt_regs *regs, unsigned long orig_i0)
474 {
475 struct ksignal ksig;
476 int restart_syscall;
477 bool has_handler;
478
479 /* It's a lot of work and synchronization to add a new ptrace
480 * register for GDB to save and restore in order to get
481 * orig_i0 correct for syscall restarts when debugging.
482 *
483 * Although it should be the case that most of the global
484 * registers are volatile across a system call, glibc already
485 * depends upon that fact that we preserve them. So we can't
486 * just use any global register to save away the orig_i0 value.
487 *
488 * In particular %g2, %g3, %g4, and %g5 are all assumed to be
489 * preserved across a system call trap by various pieces of
490 * code in glibc.
491 *
492 * %g7 is used as the "thread register". %g6 is not used in
493 * any fixed manner. %g6 is used as a scratch register and
494 * a compiler temporary, but it's value is never used across
495 * a system call. Therefore %g6 is usable for orig_i0 storage.
496 */
497 if (pt_regs_is_syscall(regs) &&
498 (regs->tstate & (TSTATE_XCARRY | TSTATE_ICARRY)))
499 regs->u_regs[UREG_G6] = orig_i0;
500
501 #ifdef CONFIG_COMPAT
502 if (test_thread_flag(TIF_32BIT)) {
503 do_signal32(regs);
504 return;
505 }
506 #endif
507
508 has_handler = get_signal(&ksig);
509
510 restart_syscall = 0;
511 if (pt_regs_is_syscall(regs) &&
512 (regs->tstate & (TSTATE_XCARRY | TSTATE_ICARRY))) {
513 restart_syscall = 1;
514 orig_i0 = regs->u_regs[UREG_G6];
515 }
516
517 if (has_handler) {
518 if (restart_syscall)
519 syscall_restart(orig_i0, regs, &ksig.ka.sa);
520 signal_setup_done(setup_rt_frame(&ksig, regs), &ksig, 0);
521 } else {
522 if (restart_syscall) {
523 switch (regs->u_regs[UREG_I0]) {
524 case ERESTARTNOHAND:
525 case ERESTARTSYS:
526 case ERESTARTNOINTR:
527 /* replay the system call when we are done */
528 regs->u_regs[UREG_I0] = orig_i0;
529 regs->tpc -= 4;
530 regs->tnpc -= 4;
531 pt_regs_clear_syscall(regs);
532 case ERESTART_RESTARTBLOCK:
533 regs->u_regs[UREG_G1] = __NR_restart_syscall;
534 regs->tpc -= 4;
535 regs->tnpc -= 4;
536 pt_regs_clear_syscall(regs);
537 }
538 }
539 restore_saved_sigmask();
540 }
541 }
542
543 void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0, unsigned long thread_info_flags)
544 {
545 user_exit();
546 if (thread_info_flags & _TIF_UPROBE)
547 uprobe_notify_resume(regs);
548 if (thread_info_flags & _TIF_SIGPENDING)
549 do_signal(regs, orig_i0);
550 if (thread_info_flags & _TIF_NOTIFY_RESUME) {
551 clear_thread_flag(TIF_NOTIFY_RESUME);
552 tracehook_notify_resume(regs);
553 }
554 user_enter();
555 }
556
CRIS linux kernel tree