1 // SPDX-License-Identifier: GPL-2.0
2 /* arch/sparc64/kernel/signal32.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
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 #include <linux/sched.h>
12 #include <linux/kernel.h>
13 #include <linux/signal.h>
14 #include <linux/errno.h>
15 #include <linux/wait.h>
16 #include <linux/ptrace.h>
17 #include <linux/unistd.h>
18 #include <linux/mm.h>
19 #include <linux/tty.h>
20 #include <linux/binfmts.h>
21 #include <linux/compat.h>
22 #include <linux/bitops.h>
23
24 #include <linux/uaccess.h>
25 #include <asm/ptrace.h>
26 #include <asm/psrcompat.h>
27 #include <asm/fpumacro.h>
28 #include <asm/visasm.h>
29 #include <asm/compat_signal.h>
30 #include <asm/switch_to.h>
31
32 #include "sigutil.h"
33 #include "kernel.h"
34
35 /* This magic should be in g_upper[0] for all upper parts
36 * to be valid.
37 */
38 #define SIGINFO_EXTRA_V8PLUS_MAGIC 0x130e269
39 typedef struct {
40 unsigned int g_upper[8];
41 unsigned int o_upper[8];
42 unsigned int asi;
43 } siginfo_extra_v8plus_t;
44
45 struct signal_frame32 {
46 struct sparc_stackf32 ss;
47 __siginfo32_t info;
48 /* __siginfo_fpu_t * */ u32 fpu_save;
49 unsigned int insns[2];
50 unsigned int extramask[_COMPAT_NSIG_WORDS - 1];
51 unsigned int extra_size; /* Should be sizeof(siginfo_extra_v8plus_t) */
52 /* Only valid if (info.si_regs.psr & (PSR_VERS|PSR_IMPL)) == PSR_V8PLUS */
53 siginfo_extra_v8plus_t v8plus;
54 /* __siginfo_rwin_t * */u32 rwin_save;
55 } __attribute__((aligned(8)));
56
57 struct rt_signal_frame32 {
58 struct sparc_stackf32 ss;
59 compat_siginfo_t info;
60 struct pt_regs32 regs;
61 compat_sigset_t mask;
62 /* __siginfo_fpu_t * */ u32 fpu_save;
63 unsigned int insns[2];
64 compat_stack_t stack;
65 unsigned int extra_size; /* Should be sizeof(siginfo_extra_v8plus_t) */
66 /* Only valid if (regs.psr & (PSR_VERS|PSR_IMPL)) == PSR_V8PLUS */
67 siginfo_extra_v8plus_t v8plus;
68 /* __siginfo_rwin_t * */u32 rwin_save;
69 } __attribute__((aligned(8)));
70
71 /* Checks if the fp is valid. We always build signal frames which are
72 * 16-byte aligned, therefore we can always enforce that the restore
73 * frame has that property as well.
74 */
invalid_frame_pointer(void __user * fp,int fplen)75 static bool invalid_frame_pointer(void __user *fp, int fplen)
76 {
77 if ((((unsigned long) fp) & 15) ||
78 ((unsigned long)fp) > 0x100000000ULL - fplen)
79 return true;
80 return false;
81 }
82
do_sigreturn32(struct pt_regs * regs)83 void do_sigreturn32(struct pt_regs *regs)
84 {
85 struct signal_frame32 __user *sf;
86 compat_uptr_t fpu_save;
87 compat_uptr_t rwin_save;
88 unsigned int psr, ufp;
89 unsigned int pc, npc;
90 sigset_t set;
91 compat_sigset_t seta;
92 int err, i;
93
94 /* Always make any pending restarted system calls return -EINTR */
95 current->restart_block.fn = do_no_restart_syscall;
96
97 synchronize_user_stack();
98
99 regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
100 sf = (struct signal_frame32 __user *) regs->u_regs[UREG_FP];
101
102 /* 1. Make sure we are not getting garbage from the user */
103 if (invalid_frame_pointer(sf, sizeof(*sf)))
104 goto segv;
105
106 if (get_user(ufp, &sf->info.si_regs.u_regs[UREG_FP]))
107 goto segv;
108
109 if (ufp & 0x7)
110 goto segv;
111
112 if (__get_user(pc, &sf->info.si_regs.pc) ||
113 __get_user(npc, &sf->info.si_regs.npc))
114 goto segv;
115
116 if ((pc | npc) & 3)
117 goto segv;
118
119 if (test_thread_flag(TIF_32BIT)) {
120 pc &= 0xffffffff;
121 npc &= 0xffffffff;
122 }
123 regs->tpc = pc;
124 regs->tnpc = npc;
125
126 /* 2. Restore the state */
127 err = __get_user(regs->y, &sf->info.si_regs.y);
128 err |= __get_user(psr, &sf->info.si_regs.psr);
129
130 for (i = UREG_G1; i <= UREG_I7; i++)
131 err |= __get_user(regs->u_regs[i], &sf->info.si_regs.u_regs[i]);
132 if ((psr & (PSR_VERS|PSR_IMPL)) == PSR_V8PLUS) {
133 err |= __get_user(i, &sf->v8plus.g_upper[0]);
134 if (i == SIGINFO_EXTRA_V8PLUS_MAGIC) {
135 unsigned long asi;
136
137 for (i = UREG_G1; i <= UREG_I7; i++)
138 err |= __get_user(((u32 *)regs->u_regs)[2*i], &sf->v8plus.g_upper[i]);
139 err |= __get_user(asi, &sf->v8plus.asi);
140 regs->tstate &= ~TSTATE_ASI;
141 regs->tstate |= ((asi & 0xffUL) << 24UL);
142 }
143 }
144
145 /* User can only change condition codes in %tstate. */
146 regs->tstate &= ~(TSTATE_ICC|TSTATE_XCC);
147 regs->tstate |= psr_to_tstate_icc(psr);
148
149 /* Prevent syscall restart. */
150 pt_regs_clear_syscall(regs);
151
152 err |= __get_user(fpu_save, &sf->fpu_save);
153 if (!err && fpu_save)
154 err |= restore_fpu_state(regs, compat_ptr(fpu_save));
155 err |= __get_user(rwin_save, &sf->rwin_save);
156 if (!err && rwin_save) {
157 if (restore_rwin_state(compat_ptr(rwin_save)))
158 goto segv;
159 }
160 err |= __get_user(seta.sig[0], &sf->info.si_mask);
161 err |= copy_from_user(&seta.sig[1], &sf->extramask,
162 (_COMPAT_NSIG_WORDS - 1) * sizeof(unsigned int));
163 if (err)
164 goto segv;
165
166 set.sig[0] = seta.sig[0] + (((long)seta.sig[1]) << 32);
167 set_current_blocked(&set);
168 return;
169
170 segv:
171 force_sig(SIGSEGV);
172 }
173
do_rt_sigreturn32(struct pt_regs * regs)174 asmlinkage void do_rt_sigreturn32(struct pt_regs *regs)
175 {
176 struct rt_signal_frame32 __user *sf;
177 unsigned int psr, pc, npc, ufp;
178 compat_uptr_t fpu_save;
179 compat_uptr_t rwin_save;
180 sigset_t set;
181 int err, i;
182
183 /* Always make any pending restarted system calls return -EINTR */
184 current->restart_block.fn = do_no_restart_syscall;
185
186 synchronize_user_stack();
187 regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
188 sf = (struct rt_signal_frame32 __user *) regs->u_regs[UREG_FP];
189
190 /* 1. Make sure we are not getting garbage from the user */
191 if (invalid_frame_pointer(sf, sizeof(*sf)))
192 goto segv;
193
194 if (get_user(ufp, &sf->regs.u_regs[UREG_FP]))
195 goto segv;
196
197 if (ufp & 0x7)
198 goto segv;
199
200 if (__get_user(pc, &sf->regs.pc) ||
201 __get_user(npc, &sf->regs.npc))
202 goto segv;
203
204 if ((pc | npc) & 3)
205 goto segv;
206
207 if (test_thread_flag(TIF_32BIT)) {
208 pc &= 0xffffffff;
209 npc &= 0xffffffff;
210 }
211 regs->tpc = pc;
212 regs->tnpc = npc;
213
214 /* 2. Restore the state */
215 err = __get_user(regs->y, &sf->regs.y);
216 err |= __get_user(psr, &sf->regs.psr);
217
218 for (i = UREG_G1; i <= UREG_I7; i++)
219 err |= __get_user(regs->u_regs[i], &sf->regs.u_regs[i]);
220 if ((psr & (PSR_VERS|PSR_IMPL)) == PSR_V8PLUS) {
221 err |= __get_user(i, &sf->v8plus.g_upper[0]);
222 if (i == SIGINFO_EXTRA_V8PLUS_MAGIC) {
223 unsigned long asi;
224
225 for (i = UREG_G1; i <= UREG_I7; i++)
226 err |= __get_user(((u32 *)regs->u_regs)[2*i], &sf->v8plus.g_upper[i]);
227 err |= __get_user(asi, &sf->v8plus.asi);
228 regs->tstate &= ~TSTATE_ASI;
229 regs->tstate |= ((asi & 0xffUL) << 24UL);
230 }
231 }
232
233 /* User can only change condition codes in %tstate. */
234 regs->tstate &= ~(TSTATE_ICC|TSTATE_XCC);
235 regs->tstate |= psr_to_tstate_icc(psr);
236
237 /* Prevent syscall restart. */
238 pt_regs_clear_syscall(regs);
239
240 err |= __get_user(fpu_save, &sf->fpu_save);
241 if (!err && fpu_save)
242 err |= restore_fpu_state(regs, compat_ptr(fpu_save));
243 err |= get_compat_sigset(&set, &sf->mask);
244 err |= compat_restore_altstack(&sf->stack);
245 if (err)
246 goto segv;
247
248 err |= __get_user(rwin_save, &sf->rwin_save);
249 if (!err && rwin_save) {
250 if (restore_rwin_state(compat_ptr(rwin_save)))
251 goto segv;
252 }
253
254 set_current_blocked(&set);
255 return;
256 segv:
257 force_sig(SIGSEGV);
258 }
259
get_sigframe(struct ksignal * ksig,struct pt_regs * regs,unsigned long framesize)260 static void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs, unsigned long framesize)
261 {
262 unsigned long sp;
263
264 regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
265 sp = regs->u_regs[UREG_FP];
266
267 /*
268 * If we are on the alternate signal stack and would overflow it, don't.
269 * Return an always-bogus address instead so we will die with SIGSEGV.
270 */
271 if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize)))
272 return (void __user *) -1L;
273
274 /* This is the X/Open sanctioned signal stack switching. */
275 sp = sigsp(sp, ksig) - framesize;
276
277 /* Always align the stack frame. This handles two cases. First,
278 * sigaltstack need not be mindful of platform specific stack
279 * alignment. Second, if we took this signal because the stack
280 * is not aligned properly, we'd like to take the signal cleanly
281 * and report that.
282 */
283 sp &= ~15UL;
284
285 return (void __user *) sp;
286 }
287
288 /* The I-cache flush instruction only works in the primary ASI, which
289 * right now is the nucleus, aka. kernel space.
290 *
291 * Therefore we have to kick the instructions out using the kernel
292 * side linear mapping of the physical address backing the user
293 * instructions.
294 */
flush_signal_insns(unsigned long address)295 static void flush_signal_insns(unsigned long address)
296 {
297 unsigned long pstate, paddr;
298 pte_t *ptep, pte;
299 pgd_t *pgdp;
300 p4d_t *p4dp;
301 pud_t *pudp;
302 pmd_t *pmdp;
303
304 /* Commit all stores of the instructions we are about to flush. */
305 wmb();
306
307 /* Disable cross-call reception. In this way even a very wide
308 * munmap() on another cpu can't tear down the page table
309 * hierarchy from underneath us, since that can't complete
310 * until the IPI tlb flush returns.
311 */
312
313 __asm__ __volatile__("rdpr %%pstate, %0" : "=r" (pstate));
314 __asm__ __volatile__("wrpr %0, %1, %%pstate"
315 : : "r" (pstate), "i" (PSTATE_IE));
316
317 pgdp = pgd_offset(current->mm, address);
318 if (pgd_none(*pgdp))
319 goto out_irqs_on;
320 p4dp = p4d_offset(pgdp, address);
321 if (p4d_none(*p4dp))
322 goto out_irqs_on;
323 pudp = pud_offset(p4dp, address);
324 if (pud_none(*pudp))
325 goto out_irqs_on;
326 pmdp = pmd_offset(pudp, address);
327 if (pmd_none(*pmdp))
328 goto out_irqs_on;
329
330 ptep = pte_offset_map(pmdp, address);
331 pte = *ptep;
332 if (!pte_present(pte))
333 goto out_unmap;
334
335 paddr = (unsigned long) page_address(pte_page(pte));
336
337 __asm__ __volatile__("flush %0 + %1"
338 : /* no outputs */
339 : "r" (paddr),
340 "r" (address & (PAGE_SIZE - 1))
341 : "memory");
342
343 out_unmap:
344 pte_unmap(ptep);
345 out_irqs_on:
346 __asm__ __volatile__("wrpr %0, 0x0, %%pstate" : : "r" (pstate));
347
348 }
349
setup_frame32(struct ksignal * ksig,struct pt_regs * regs,sigset_t * oldset)350 static int setup_frame32(struct ksignal *ksig, struct pt_regs *regs,
351 sigset_t *oldset)
352 {
353 struct signal_frame32 __user *sf;
354 int i, err, wsaved;
355 void __user *tail;
356 int sigframe_size;
357 u32 psr;
358 compat_sigset_t seta;
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 sigframe_size = sizeof(*sf);
367 if (current_thread_info()->fpsaved[0] & FPRS_FEF)
368 sigframe_size += sizeof(__siginfo_fpu_t);
369 if (wsaved)
370 sigframe_size += sizeof(__siginfo_rwin_t);
371
372 sf = (struct signal_frame32 __user *)
373 get_sigframe(ksig, regs, sigframe_size);
374
375 if (invalid_frame_pointer(sf, sigframe_size)) {
376 if (show_unhandled_signals)
377 pr_info("%s[%d] bad frame in setup_frame32: %08lx TPC %08lx O7 %08lx\n",
378 current->comm, current->pid, (unsigned long)sf,
379 regs->tpc, regs->u_regs[UREG_I7]);
380 force_sigsegv(ksig->sig);
381 return -EINVAL;
382 }
383
384 tail = (sf + 1);
385
386 /* 2. Save the current process state */
387 if (test_thread_flag(TIF_32BIT)) {
388 regs->tpc &= 0xffffffff;
389 regs->tnpc &= 0xffffffff;
390 }
391 err = put_user(regs->tpc, &sf->info.si_regs.pc);
392 err |= __put_user(regs->tnpc, &sf->info.si_regs.npc);
393 err |= __put_user(regs->y, &sf->info.si_regs.y);
394 psr = tstate_to_psr(regs->tstate);
395 if (current_thread_info()->fpsaved[0] & FPRS_FEF)
396 psr |= PSR_EF;
397 err |= __put_user(psr, &sf->info.si_regs.psr);
398 for (i = 0; i < 16; i++)
399 err |= __put_user(regs->u_regs[i], &sf->info.si_regs.u_regs[i]);
400 err |= __put_user(sizeof(siginfo_extra_v8plus_t), &sf->extra_size);
401 err |= __put_user(SIGINFO_EXTRA_V8PLUS_MAGIC, &sf->v8plus.g_upper[0]);
402 for (i = 1; i < 16; i++)
403 err |= __put_user(((u32 *)regs->u_regs)[2*i],
404 &sf->v8plus.g_upper[i]);
405 err |= __put_user((regs->tstate & TSTATE_ASI) >> 24UL,
406 &sf->v8plus.asi);
407
408 if (psr & PSR_EF) {
409 __siginfo_fpu_t __user *fp = tail;
410 tail += sizeof(*fp);
411 err |= save_fpu_state(regs, fp);
412 err |= __put_user((u64)fp, &sf->fpu_save);
413 } else {
414 err |= __put_user(0, &sf->fpu_save);
415 }
416 if (wsaved) {
417 __siginfo_rwin_t __user *rwp = tail;
418 tail += sizeof(*rwp);
419 err |= save_rwin_state(wsaved, rwp);
420 err |= __put_user((u64)rwp, &sf->rwin_save);
421 set_thread_wsaved(0);
422 } else {
423 err |= __put_user(0, &sf->rwin_save);
424 }
425
426 /* If these change we need to know - assignments to seta relies on these sizes */
427 BUILD_BUG_ON(_NSIG_WORDS != 1);
428 BUILD_BUG_ON(_COMPAT_NSIG_WORDS != 2);
429 seta.sig[1] = (oldset->sig[0] >> 32);
430 seta.sig[0] = oldset->sig[0];
431
432 err |= __put_user(seta.sig[0], &sf->info.si_mask);
433 err |= __copy_to_user(sf->extramask, &seta.sig[1],
434 (_COMPAT_NSIG_WORDS - 1) * sizeof(unsigned int));
435
436 if (!wsaved) {
437 err |= raw_copy_in_user((u32 __user *)sf,
438 (u32 __user *)(regs->u_regs[UREG_FP]),
439 sizeof(struct reg_window32));
440 } else {
441 struct reg_window *rp;
442
443 rp = ¤t_thread_info()->reg_window[wsaved - 1];
444 for (i = 0; i < 8; i++)
445 err |= __put_user(rp->locals[i], &sf->ss.locals[i]);
446 for (i = 0; i < 6; i++)
447 err |= __put_user(rp->ins[i], &sf->ss.ins[i]);
448 err |= __put_user(rp->ins[6], &sf->ss.fp);
449 err |= __put_user(rp->ins[7], &sf->ss.callers_pc);
450 }
451 if (err)
452 return err;
453
454 /* 3. signal handler back-trampoline and parameters */
455 regs->u_regs[UREG_FP] = (unsigned long) sf;
456 regs->u_regs[UREG_I0] = ksig->sig;
457 regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
458 regs->u_regs[UREG_I2] = (unsigned long) &sf->info;
459
460 /* 4. signal handler */
461 regs->tpc = (unsigned long) ksig->ka.sa.sa_handler;
462 regs->tnpc = (regs->tpc + 4);
463 if (test_thread_flag(TIF_32BIT)) {
464 regs->tpc &= 0xffffffff;
465 regs->tnpc &= 0xffffffff;
466 }
467
468 /* 5. return to kernel instructions */
469 if (ksig->ka.ka_restorer) {
470 regs->u_regs[UREG_I7] = (unsigned long)ksig->ka.ka_restorer;
471 } else {
472 unsigned long address = ((unsigned long)&(sf->insns[0]));
473
474 regs->u_regs[UREG_I7] = (unsigned long) (&(sf->insns[0]) - 2);
475
476 err = __put_user(0x821020d8, &sf->insns[0]); /*mov __NR_sigreturn, %g1*/
477 err |= __put_user(0x91d02010, &sf->insns[1]); /*t 0x10*/
478 if (err)
479 return err;
480 flush_signal_insns(address);
481 }
482 return 0;
483 }
484
setup_rt_frame32(struct ksignal * ksig,struct pt_regs * regs,sigset_t * oldset)485 static int setup_rt_frame32(struct ksignal *ksig, struct pt_regs *regs,
486 sigset_t *oldset)
487 {
488 struct rt_signal_frame32 __user *sf;
489 int i, err, wsaved;
490 void __user *tail;
491 int sigframe_size;
492 u32 psr;
493
494 /* 1. Make sure everything is clean */
495 synchronize_user_stack();
496 save_and_clear_fpu();
497
498 wsaved = get_thread_wsaved();
499
500 sigframe_size = sizeof(*sf);
501 if (current_thread_info()->fpsaved[0] & FPRS_FEF)
502 sigframe_size += sizeof(__siginfo_fpu_t);
503 if (wsaved)
504 sigframe_size += sizeof(__siginfo_rwin_t);
505
506 sf = (struct rt_signal_frame32 __user *)
507 get_sigframe(ksig, regs, sigframe_size);
508
509 if (invalid_frame_pointer(sf, sigframe_size)) {
510 if (show_unhandled_signals)
511 pr_info("%s[%d] bad frame in setup_rt_frame32: %08lx TPC %08lx O7 %08lx\n",
512 current->comm, current->pid, (unsigned long)sf,
513 regs->tpc, regs->u_regs[UREG_I7]);
514 force_sigsegv(ksig->sig);
515 return -EINVAL;
516 }
517
518 tail = (sf + 1);
519
520 /* 2. Save the current process state */
521 if (test_thread_flag(TIF_32BIT)) {
522 regs->tpc &= 0xffffffff;
523 regs->tnpc &= 0xffffffff;
524 }
525 err = put_user(regs->tpc, &sf->regs.pc);
526 err |= __put_user(regs->tnpc, &sf->regs.npc);
527 err |= __put_user(regs->y, &sf->regs.y);
528 psr = tstate_to_psr(regs->tstate);
529 if (current_thread_info()->fpsaved[0] & FPRS_FEF)
530 psr |= PSR_EF;
531 err |= __put_user(psr, &sf->regs.psr);
532 for (i = 0; i < 16; i++)
533 err |= __put_user(regs->u_regs[i], &sf->regs.u_regs[i]);
534 err |= __put_user(sizeof(siginfo_extra_v8plus_t), &sf->extra_size);
535 err |= __put_user(SIGINFO_EXTRA_V8PLUS_MAGIC, &sf->v8plus.g_upper[0]);
536 for (i = 1; i < 16; i++)
537 err |= __put_user(((u32 *)regs->u_regs)[2*i],
538 &sf->v8plus.g_upper[i]);
539 err |= __put_user((regs->tstate & TSTATE_ASI) >> 24UL,
540 &sf->v8plus.asi);
541
542 if (psr & PSR_EF) {
543 __siginfo_fpu_t __user *fp = tail;
544 tail += sizeof(*fp);
545 err |= save_fpu_state(regs, fp);
546 err |= __put_user((u64)fp, &sf->fpu_save);
547 } else {
548 err |= __put_user(0, &sf->fpu_save);
549 }
550 if (wsaved) {
551 __siginfo_rwin_t __user *rwp = tail;
552 tail += sizeof(*rwp);
553 err |= save_rwin_state(wsaved, rwp);
554 err |= __put_user((u64)rwp, &sf->rwin_save);
555 set_thread_wsaved(0);
556 } else {
557 err |= __put_user(0, &sf->rwin_save);
558 }
559
560 /* Update the siginfo structure. */
561 err |= copy_siginfo_to_user32(&sf->info, &ksig->info);
562
563 /* Setup sigaltstack */
564 err |= __compat_save_altstack(&sf->stack, regs->u_regs[UREG_FP]);
565
566 err |= put_compat_sigset(&sf->mask, oldset, sizeof(compat_sigset_t));
567
568 if (!wsaved) {
569 err |= raw_copy_in_user((u32 __user *)sf,
570 (u32 __user *)(regs->u_regs[UREG_FP]),
571 sizeof(struct reg_window32));
572 } else {
573 struct reg_window *rp;
574
575 rp = ¤t_thread_info()->reg_window[wsaved - 1];
576 for (i = 0; i < 8; i++)
577 err |= __put_user(rp->locals[i], &sf->ss.locals[i]);
578 for (i = 0; i < 6; i++)
579 err |= __put_user(rp->ins[i], &sf->ss.ins[i]);
580 err |= __put_user(rp->ins[6], &sf->ss.fp);
581 err |= __put_user(rp->ins[7], &sf->ss.callers_pc);
582 }
583 if (err)
584 return err;
585
586 /* 3. signal handler back-trampoline and parameters */
587 regs->u_regs[UREG_FP] = (unsigned long) sf;
588 regs->u_regs[UREG_I0] = ksig->sig;
589 regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
590 regs->u_regs[UREG_I2] = (unsigned long) &sf->regs;
591
592 /* 4. signal handler */
593 regs->tpc = (unsigned long) ksig->ka.sa.sa_handler;
594 regs->tnpc = (regs->tpc + 4);
595 if (test_thread_flag(TIF_32BIT)) {
596 regs->tpc &= 0xffffffff;
597 regs->tnpc &= 0xffffffff;
598 }
599
600 /* 5. return to kernel instructions */
601 if (ksig->ka.ka_restorer)
602 regs->u_regs[UREG_I7] = (unsigned long)ksig->ka.ka_restorer;
603 else {
604 unsigned long address = ((unsigned long)&(sf->insns[0]));
605
606 regs->u_regs[UREG_I7] = (unsigned long) (&(sf->insns[0]) - 2);
607
608 /* mov __NR_rt_sigreturn, %g1 */
609 err |= __put_user(0x82102065, &sf->insns[0]);
610
611 /* t 0x10 */
612 err |= __put_user(0x91d02010, &sf->insns[1]);
613 if (err)
614 return err;
615
616 flush_signal_insns(address);
617 }
618 return 0;
619 }
620
handle_signal32(struct ksignal * ksig,struct pt_regs * regs)621 static inline void handle_signal32(struct ksignal *ksig,
622 struct pt_regs *regs)
623 {
624 sigset_t *oldset = sigmask_to_save();
625 int err;
626
627 if (ksig->ka.sa.sa_flags & SA_SIGINFO)
628 err = setup_rt_frame32(ksig, regs, oldset);
629 else
630 err = setup_frame32(ksig, regs, oldset);
631
632 signal_setup_done(err, ksig, 0);
633 }
634
syscall_restart32(unsigned long orig_i0,struct pt_regs * regs,struct sigaction * sa)635 static inline void syscall_restart32(unsigned long orig_i0, struct pt_regs *regs,
636 struct sigaction *sa)
637 {
638 switch (regs->u_regs[UREG_I0]) {
639 case ERESTART_RESTARTBLOCK:
640 case ERESTARTNOHAND:
641 no_system_call_restart:
642 regs->u_regs[UREG_I0] = EINTR;
643 regs->tstate |= TSTATE_ICARRY;
644 break;
645 case ERESTARTSYS:
646 if (!(sa->sa_flags & SA_RESTART))
647 goto no_system_call_restart;
648 fallthrough;
649 case ERESTARTNOINTR:
650 regs->u_regs[UREG_I0] = orig_i0;
651 regs->tpc -= 4;
652 regs->tnpc -= 4;
653 }
654 }
655
656 /* Note that 'init' is a special process: it doesn't get signals it doesn't
657 * want to handle. Thus you cannot kill init even with a SIGKILL even by
658 * mistake.
659 */
do_signal32(struct pt_regs * regs)660 void do_signal32(struct pt_regs * regs)
661 {
662 struct ksignal ksig;
663 unsigned long orig_i0 = 0;
664 int restart_syscall = 0;
665 bool has_handler = get_signal(&ksig);
666
667 if (pt_regs_is_syscall(regs) &&
668 (regs->tstate & (TSTATE_XCARRY | TSTATE_ICARRY))) {
669 restart_syscall = 1;
670 orig_i0 = regs->u_regs[UREG_G6];
671 }
672
673 if (has_handler) {
674 if (restart_syscall)
675 syscall_restart32(orig_i0, regs, &ksig.ka.sa);
676 handle_signal32(&ksig, regs);
677 } else {
678 if (restart_syscall) {
679 switch (regs->u_regs[UREG_I0]) {
680 case ERESTARTNOHAND:
681 case ERESTARTSYS:
682 case ERESTARTNOINTR:
683 /* replay the system call when we are done */
684 regs->u_regs[UREG_I0] = orig_i0;
685 regs->tpc -= 4;
686 regs->tnpc -= 4;
687 pt_regs_clear_syscall(regs);
688 fallthrough;
689 case ERESTART_RESTARTBLOCK:
690 regs->u_regs[UREG_G1] = __NR_restart_syscall;
691 regs->tpc -= 4;
692 regs->tnpc -= 4;
693 pt_regs_clear_syscall(regs);
694 }
695 }
696 restore_saved_sigmask();
697 }
698 }
699
700 struct sigstack32 {
701 u32 the_stack;
702 int cur_status;
703 };
704
do_sys32_sigstack(u32 u_ssptr,u32 u_ossptr,unsigned long sp)705 asmlinkage int do_sys32_sigstack(u32 u_ssptr, u32 u_ossptr, unsigned long sp)
706 {
707 struct sigstack32 __user *ssptr =
708 (struct sigstack32 __user *)((unsigned long)(u_ssptr));
709 struct sigstack32 __user *ossptr =
710 (struct sigstack32 __user *)((unsigned long)(u_ossptr));
711 int ret = -EFAULT;
712
713 /* First see if old state is wanted. */
714 if (ossptr) {
715 if (put_user(current->sas_ss_sp + current->sas_ss_size,
716 &ossptr->the_stack) ||
717 __put_user(on_sig_stack(sp), &ossptr->cur_status))
718 goto out;
719 }
720
721 /* Now see if we want to update the new state. */
722 if (ssptr) {
723 u32 ss_sp;
724
725 if (get_user(ss_sp, &ssptr->the_stack))
726 goto out;
727
728 /* If the current stack was set with sigaltstack, don't
729 * swap stacks while we are on it.
730 */
731 ret = -EPERM;
732 if (current->sas_ss_sp && on_sig_stack(sp))
733 goto out;
734
735 /* Since we don't know the extent of the stack, and we don't
736 * track onstack-ness, but rather calculate it, we must
737 * presume a size. Ho hum this interface is lossy.
738 */
739 current->sas_ss_sp = (unsigned long)ss_sp - SIGSTKSZ;
740 current->sas_ss_size = SIGSTKSZ;
741 }
742
743 ret = 0;
744 out:
745 return ret;
746 }
747
748 /*
749 * Compile-time assertions for siginfo_t offsets. Check NSIG* as well, as
750 * changes likely come with new fields that should be added below.
751 */
752 static_assert(NSIGILL == 11);
753 static_assert(NSIGFPE == 15);
754 static_assert(NSIGSEGV == 9);
755 static_assert(NSIGBUS == 5);
756 static_assert(NSIGTRAP == 6);
757 static_assert(NSIGCHLD == 6);
758 static_assert(NSIGSYS == 2);
759 static_assert(sizeof(compat_siginfo_t) == 128);
760 static_assert(__alignof__(compat_siginfo_t) == 4);
761 static_assert(offsetof(compat_siginfo_t, si_signo) == 0x00);
762 static_assert(offsetof(compat_siginfo_t, si_errno) == 0x04);
763 static_assert(offsetof(compat_siginfo_t, si_code) == 0x08);
764 static_assert(offsetof(compat_siginfo_t, si_pid) == 0x0c);
765 static_assert(offsetof(compat_siginfo_t, si_uid) == 0x10);
766 static_assert(offsetof(compat_siginfo_t, si_tid) == 0x0c);
767 static_assert(offsetof(compat_siginfo_t, si_overrun) == 0x10);
768 static_assert(offsetof(compat_siginfo_t, si_status) == 0x14);
769 static_assert(offsetof(compat_siginfo_t, si_utime) == 0x18);
770 static_assert(offsetof(compat_siginfo_t, si_stime) == 0x1c);
771 static_assert(offsetof(compat_siginfo_t, si_value) == 0x14);
772 static_assert(offsetof(compat_siginfo_t, si_int) == 0x14);
773 static_assert(offsetof(compat_siginfo_t, si_ptr) == 0x14);
774 static_assert(offsetof(compat_siginfo_t, si_addr) == 0x0c);
775 static_assert(offsetof(compat_siginfo_t, si_trapno) == 0x10);
776 static_assert(offsetof(compat_siginfo_t, si_addr_lsb) == 0x10);
777 static_assert(offsetof(compat_siginfo_t, si_lower) == 0x14);
778 static_assert(offsetof(compat_siginfo_t, si_upper) == 0x18);
779 static_assert(offsetof(compat_siginfo_t, si_pkey) == 0x14);
780 static_assert(offsetof(compat_siginfo_t, si_perf_data) == 0x10);
781 static_assert(offsetof(compat_siginfo_t, si_perf_type) == 0x14);
782 static_assert(offsetof(compat_siginfo_t, si_perf_flags) == 0x18);
783 static_assert(offsetof(compat_siginfo_t, si_band) == 0x0c);
784 static_assert(offsetof(compat_siginfo_t, si_fd) == 0x10);
785