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1/*
2 * Signal handling for 32bit PPC and 32bit tasks on 64bit PPC
3 *
4 * PowerPC version
5 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
6 * Copyright (C) 2001 IBM
7 * Copyright (C) 1997,1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
8 * Copyright (C) 1997 David S. Miller (davem@caip.rutgers.edu)
9 *
10 * Derived from "arch/i386/kernel/signal.c"
11 * Copyright (C) 1991, 1992 Linus Torvalds
12 * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
13 *
14 * This program is free software; you can redistribute it and/or
15 * modify it under the terms of the GNU General Public License
16 * as published by the Free Software Foundation; either version
17 * 2 of the License, or (at your option) any later version.
18 */
19
20#include <linux/sched.h>
21#include <linux/mm.h>
22#include <linux/smp.h>
23#include <linux/kernel.h>
24#include <linux/signal.h>
25#include <linux/errno.h>
26#include <linux/elf.h>
27#include <linux/ptrace.h>
28#include <linux/ratelimit.h>
29#ifdef CONFIG_PPC64
30#include <linux/syscalls.h>
31#include <linux/compat.h>
32#else
33#include <linux/wait.h>
34#include <linux/unistd.h>
35#include <linux/stddef.h>
36#include <linux/tty.h>
37#include <linux/binfmts.h>
38#endif
39
40#include <linux/uaccess.h>
41#include <asm/cacheflush.h>
42#include <asm/syscalls.h>
43#include <asm/sigcontext.h>
44#include <asm/vdso.h>
45#include <asm/switch_to.h>
46#include <asm/tm.h>
47#include <asm/asm-prototypes.h>
48#ifdef CONFIG_PPC64
49#include "ppc32.h"
50#include <asm/unistd.h>
51#else
52#include <asm/ucontext.h>
53#include <asm/pgtable.h>
54#endif
55
56#include "signal.h"
57
58
59#ifdef CONFIG_PPC64
60#define sys_rt_sigreturn compat_sys_rt_sigreturn
61#define sys_swapcontext compat_sys_swapcontext
62#define sys_sigreturn compat_sys_sigreturn
63
64#define old_sigaction old_sigaction32
65#define sigcontext sigcontext32
66#define mcontext mcontext32
67#define ucontext ucontext32
68
69#define __save_altstack __compat_save_altstack
70
71/*
72 * Userspace code may pass a ucontext which doesn't include VSX added
73 * at the end. We need to check for this case.
74 */
75#define UCONTEXTSIZEWITHOUTVSX \
76 (sizeof(struct ucontext) - sizeof(elf_vsrreghalf_t32))
77
78/*
79 * Returning 0 means we return to userspace via
80 * ret_from_except and thus restore all user
81 * registers from *regs. This is what we need
82 * to do when a signal has been delivered.
83 */
84
85#define GP_REGS_SIZE min(sizeof(elf_gregset_t32), sizeof(struct pt_regs32))
86#undef __SIGNAL_FRAMESIZE
87#define __SIGNAL_FRAMESIZE __SIGNAL_FRAMESIZE32
88#undef ELF_NVRREG
89#define ELF_NVRREG ELF_NVRREG32
90
91/*
92 * Functions for flipping sigsets (thanks to brain dead generic
93 * implementation that makes things simple for little endian only)
94 */
95static inline int put_sigset_t(compat_sigset_t __user *uset, sigset_t *set)
96{
97 return put_compat_sigset(uset, set, sizeof(*uset));
98}
99
100static inline int get_sigset_t(sigset_t *set,
101 const compat_sigset_t __user *uset)
102{
103 return get_compat_sigset(set, uset);
104}
105
106#define to_user_ptr(p) ptr_to_compat(p)
107#define from_user_ptr(p) compat_ptr(p)
108
109static inline int save_general_regs(struct pt_regs *regs,
110 struct mcontext __user *frame)
111{
112 elf_greg_t64 *gregs = (elf_greg_t64 *)regs;
113 int i;
114 /* Force usr to alway see softe as 1 (interrupts enabled) */
115 elf_greg_t64 softe = 0x1;
116
117 WARN_ON(!FULL_REGS(regs));
118
119 for (i = 0; i <= PT_RESULT; i ++) {
120 if (i == 14 && !FULL_REGS(regs))
121 i = 32;
122 if ( i == PT_SOFTE) {
123 if(__put_user((unsigned int)softe, &frame->mc_gregs[i]))
124 return -EFAULT;
125 else
126 continue;
127 }
128 if (__put_user((unsigned int)gregs[i], &frame->mc_gregs[i]))
129 return -EFAULT;
130 }
131 return 0;
132}
133
134static inline int restore_general_regs(struct pt_regs *regs,
135 struct mcontext __user *sr)
136{
137 elf_greg_t64 *gregs = (elf_greg_t64 *)regs;
138 int i;
139
140 for (i = 0; i <= PT_RESULT; i++) {
141 if ((i == PT_MSR) || (i == PT_SOFTE))
142 continue;
143 if (__get_user(gregs[i], &sr->mc_gregs[i]))
144 return -EFAULT;
145 }
146 return 0;
147}
148
149#else /* CONFIG_PPC64 */
150
151#define GP_REGS_SIZE min(sizeof(elf_gregset_t), sizeof(struct pt_regs))
152
153static inline int put_sigset_t(sigset_t __user *uset, sigset_t *set)
154{
155 return copy_to_user(uset, set, sizeof(*uset));
156}
157
158static inline int get_sigset_t(sigset_t *set, const sigset_t __user *uset)
159{
160 return copy_from_user(set, uset, sizeof(*uset));
161}
162
163#define to_user_ptr(p) ((unsigned long)(p))
164#define from_user_ptr(p) ((void __user *)(p))
165
166static inline int save_general_regs(struct pt_regs *regs,
167 struct mcontext __user *frame)
168{
169 WARN_ON(!FULL_REGS(regs));
170 return __copy_to_user(&frame->mc_gregs, regs, GP_REGS_SIZE);
171}
172
173static inline int restore_general_regs(struct pt_regs *regs,
174 struct mcontext __user *sr)
175{
176 /* copy up to but not including MSR */
177 if (__copy_from_user(regs, &sr->mc_gregs,
178 PT_MSR * sizeof(elf_greg_t)))
179 return -EFAULT;
180 /* copy from orig_r3 (the word after the MSR) up to the end */
181 if (__copy_from_user(®s->orig_gpr3, &sr->mc_gregs[PT_ORIG_R3],
182 GP_REGS_SIZE - PT_ORIG_R3 * sizeof(elf_greg_t)))
183 return -EFAULT;
184 return 0;
185}
186#endif
187
188/*
189 * When we have signals to deliver, we set up on the
190 * user stack, going down from the original stack pointer:
191 * an ABI gap of 56 words
192 * an mcontext struct
193 * a sigcontext struct
194 * a gap of __SIGNAL_FRAMESIZE bytes
195 *
196 * Each of these things must be a multiple of 16 bytes in size. The following
197 * structure represent all of this except the __SIGNAL_FRAMESIZE gap
198 *
199 */
200struct sigframe {
201 struct sigcontext sctx; /* the sigcontext */
202 struct mcontext mctx; /* all the register values */
203#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
204 struct sigcontext sctx_transact;
205 struct mcontext mctx_transact;
206#endif
207 /*
208 * Programs using the rs6000/xcoff abi can save up to 19 gp
209 * regs and 18 fp regs below sp before decrementing it.
210 */
211 int abigap[56];
212};
213
214/* We use the mc_pad field for the signal return trampoline. */
215#define tramp mc_pad
216
217/*
218 * When we have rt signals to deliver, we set up on the
219 * user stack, going down from the original stack pointer:
220 * one rt_sigframe struct (siginfo + ucontext + ABI gap)
221 * a gap of __SIGNAL_FRAMESIZE+16 bytes
222 * (the +16 is to get the siginfo and ucontext in the same
223 * positions as in older kernels).
224 *
225 * Each of these things must be a multiple of 16 bytes in size.
226 *
227 */
228struct rt_sigframe {
229#ifdef CONFIG_PPC64
230 compat_siginfo_t info;
231#else
232 struct siginfo info;
233#endif
234 struct ucontext uc;
235#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
236 struct ucontext uc_transact;
237#endif
238 /*
239 * Programs using the rs6000/xcoff abi can save up to 19 gp
240 * regs and 18 fp regs below sp before decrementing it.
241 */
242 int abigap[56];
243};
244
245#ifdef CONFIG_VSX
246unsigned long copy_fpr_to_user(void __user *to,
247 struct task_struct *task)
248{
249 u64 buf[ELF_NFPREG];
250 int i;
251
252 /* save FPR copy to local buffer then write to the thread_struct */
253 for (i = 0; i < (ELF_NFPREG - 1) ; i++)
254 buf[i] = task->thread.TS_FPR(i);
255 buf[i] = task->thread.fp_state.fpscr;
256 return __copy_to_user(to, buf, ELF_NFPREG * sizeof(double));
257}
258
259unsigned long copy_fpr_from_user(struct task_struct *task,
260 void __user *from)
261{
262 u64 buf[ELF_NFPREG];
263 int i;
264
265 if (__copy_from_user(buf, from, ELF_NFPREG * sizeof(double)))
266 return 1;
267 for (i = 0; i < (ELF_NFPREG - 1) ; i++)
268 task->thread.TS_FPR(i) = buf[i];
269 task->thread.fp_state.fpscr = buf[i];
270
271 return 0;
272}
273
274unsigned long copy_vsx_to_user(void __user *to,
275 struct task_struct *task)
276{
277 u64 buf[ELF_NVSRHALFREG];
278 int i;
279
280 /* save FPR copy to local buffer then write to the thread_struct */
281 for (i = 0; i < ELF_NVSRHALFREG; i++)
282 buf[i] = task->thread.fp_state.fpr[i][TS_VSRLOWOFFSET];
283 return __copy_to_user(to, buf, ELF_NVSRHALFREG * sizeof(double));
284}
285
286unsigned long copy_vsx_from_user(struct task_struct *task,
287 void __user *from)
288{
289 u64 buf[ELF_NVSRHALFREG];
290 int i;
291
292 if (__copy_from_user(buf, from, ELF_NVSRHALFREG * sizeof(double)))
293 return 1;
294 for (i = 0; i < ELF_NVSRHALFREG ; i++)
295 task->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = buf[i];
296 return 0;
297}
298
299#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
300unsigned long copy_ckfpr_to_user(void __user *to,
301 struct task_struct *task)
302{
303 u64 buf[ELF_NFPREG];
304 int i;
305
306 /* save FPR copy to local buffer then write to the thread_struct */
307 for (i = 0; i < (ELF_NFPREG - 1) ; i++)
308 buf[i] = task->thread.TS_CKFPR(i);
309 buf[i] = task->thread.ckfp_state.fpscr;
310 return __copy_to_user(to, buf, ELF_NFPREG * sizeof(double));
311}
312
313unsigned long copy_ckfpr_from_user(struct task_struct *task,
314 void __user *from)
315{
316 u64 buf[ELF_NFPREG];
317 int i;
318
319 if (__copy_from_user(buf, from, ELF_NFPREG * sizeof(double)))
320 return 1;
321 for (i = 0; i < (ELF_NFPREG - 1) ; i++)
322 task->thread.TS_CKFPR(i) = buf[i];
323 task->thread.ckfp_state.fpscr = buf[i];
324
325 return 0;
326}
327
328unsigned long copy_ckvsx_to_user(void __user *to,
329 struct task_struct *task)
330{
331 u64 buf[ELF_NVSRHALFREG];
332 int i;
333
334 /* save FPR copy to local buffer then write to the thread_struct */
335 for (i = 0; i < ELF_NVSRHALFREG; i++)
336 buf[i] = task->thread.ckfp_state.fpr[i][TS_VSRLOWOFFSET];
337 return __copy_to_user(to, buf, ELF_NVSRHALFREG * sizeof(double));
338}
339
340unsigned long copy_ckvsx_from_user(struct task_struct *task,
341 void __user *from)
342{
343 u64 buf[ELF_NVSRHALFREG];
344 int i;
345
346 if (__copy_from_user(buf, from, ELF_NVSRHALFREG * sizeof(double)))
347 return 1;
348 for (i = 0; i < ELF_NVSRHALFREG ; i++)
349 task->thread.ckfp_state.fpr[i][TS_VSRLOWOFFSET] = buf[i];
350 return 0;
351}
352#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
353#else
354inline unsigned long copy_fpr_to_user(void __user *to,
355 struct task_struct *task)
356{
357 return __copy_to_user(to, task->thread.fp_state.fpr,
358 ELF_NFPREG * sizeof(double));
359}
360
361inline unsigned long copy_fpr_from_user(struct task_struct *task,
362 void __user *from)
363{
364 return __copy_from_user(task->thread.fp_state.fpr, from,
365 ELF_NFPREG * sizeof(double));
366}
367
368#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
369inline unsigned long copy_ckfpr_to_user(void __user *to,
370 struct task_struct *task)
371{
372 return __copy_to_user(to, task->thread.ckfp_state.fpr,
373 ELF_NFPREG * sizeof(double));
374}
375
376inline unsigned long copy_ckfpr_from_user(struct task_struct *task,
377 void __user *from)
378{
379 return __copy_from_user(task->thread.ckfp_state.fpr, from,
380 ELF_NFPREG * sizeof(double));
381}
382#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
383#endif
384
385/*
386 * Save the current user registers on the user stack.
387 * We only save the altivec/spe registers if the process has used
388 * altivec/spe instructions at some point.
389 */
390static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
391 struct mcontext __user *tm_frame, int sigret,
392 int ctx_has_vsx_region)
393{
394 unsigned long msr = regs->msr;
395
396 /* Make sure floating point registers are stored in regs */
397 flush_fp_to_thread(current);
398
399 /* save general registers */
400 if (save_general_regs(regs, frame))
401 return 1;
402
403#ifdef CONFIG_ALTIVEC
404 /* save altivec registers */
405 if (current->thread.used_vr) {
406 flush_altivec_to_thread(current);
407 if (__copy_to_user(&frame->mc_vregs, ¤t->thread.vr_state,
408 ELF_NVRREG * sizeof(vector128)))
409 return 1;
410 /* set MSR_VEC in the saved MSR value to indicate that
411 frame->mc_vregs contains valid data */
412 msr |= MSR_VEC;
413 }
414 /* else assert((regs->msr & MSR_VEC) == 0) */
415
416 /* We always copy to/from vrsave, it's 0 if we don't have or don't
417 * use altivec. Since VSCR only contains 32 bits saved in the least
418 * significant bits of a vector, we "cheat" and stuff VRSAVE in the
419 * most significant bits of that same vector. --BenH
420 * Note that the current VRSAVE value is in the SPR at this point.
421 */
422 if (cpu_has_feature(CPU_FTR_ALTIVEC))
423 current->thread.vrsave = mfspr(SPRN_VRSAVE);
424 if (__put_user(current->thread.vrsave, (u32 __user *)&frame->mc_vregs[32]))
425 return 1;
426#endif /* CONFIG_ALTIVEC */
427 if (copy_fpr_to_user(&frame->mc_fregs, current))
428 return 1;
429
430 /*
431 * Clear the MSR VSX bit to indicate there is no valid state attached
432 * to this context, except in the specific case below where we set it.
433 */
434 msr &= ~MSR_VSX;
435#ifdef CONFIG_VSX
436 /*
437 * Copy VSR 0-31 upper half from thread_struct to local
438 * buffer, then write that to userspace. Also set MSR_VSX in
439 * the saved MSR value to indicate that frame->mc_vregs
440 * contains valid data
441 */
442 if (current->thread.used_vsr && ctx_has_vsx_region) {
443 flush_vsx_to_thread(current);
444 if (copy_vsx_to_user(&frame->mc_vsregs, current))
445 return 1;
446 msr |= MSR_VSX;
447 }
448#endif /* CONFIG_VSX */
449#ifdef CONFIG_SPE
450 /* save spe registers */
451 if (current->thread.used_spe) {
452 flush_spe_to_thread(current);
453 if (__copy_to_user(&frame->mc_vregs, current->thread.evr,
454 ELF_NEVRREG * sizeof(u32)))
455 return 1;
456 /* set MSR_SPE in the saved MSR value to indicate that
457 frame->mc_vregs contains valid data */
458 msr |= MSR_SPE;
459 }
460 /* else assert((regs->msr & MSR_SPE) == 0) */
461
462 /* We always copy to/from spefscr */
463 if (__put_user(current->thread.spefscr, (u32 __user *)&frame->mc_vregs + ELF_NEVRREG))
464 return 1;
465#endif /* CONFIG_SPE */
466
467 if (__put_user(msr, &frame->mc_gregs[PT_MSR]))
468 return 1;
469 /* We need to write 0 the MSR top 32 bits in the tm frame so that we
470 * can check it on the restore to see if TM is active
471 */
472 if (tm_frame && __put_user(0, &tm_frame->mc_gregs[PT_MSR]))
473 return 1;
474
475 if (sigret) {
476 /* Set up the sigreturn trampoline: li r0,sigret; sc */
477 if (__put_user(0x38000000UL + sigret, &frame->tramp[0])
478 || __put_user(0x44000002UL, &frame->tramp[1]))
479 return 1;
480 flush_icache_range((unsigned long) &frame->tramp[0],
481 (unsigned long) &frame->tramp[2]);
482 }
483
484 return 0;
485}
486
487#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
488/*
489 * Save the current user registers on the user stack.
490 * We only save the altivec/spe registers if the process has used
491 * altivec/spe instructions at some point.
492 * We also save the transactional registers to a second ucontext in the
493 * frame.
494 *
495 * See save_user_regs() and signal_64.c:setup_tm_sigcontexts().
496 */
497static int save_tm_user_regs(struct pt_regs *regs,
498 struct mcontext __user *frame,
499 struct mcontext __user *tm_frame, int sigret)
500{
501 unsigned long msr = regs->msr;
502
503 WARN_ON(tm_suspend_disabled);
504
505 /* Remove TM bits from thread's MSR. The MSR in the sigcontext
506 * just indicates to userland that we were doing a transaction, but we
507 * don't want to return in transactional state. This also ensures
508 * that flush_fp_to_thread won't set TIF_RESTORE_TM again.
509 */
510 regs->msr &= ~MSR_TS_MASK;
511
512 /* Save both sets of general registers */
513 if (save_general_regs(¤t->thread.ckpt_regs, frame)
514 || save_general_regs(regs, tm_frame))
515 return 1;
516
517 /* Stash the top half of the 64bit MSR into the 32bit MSR word
518 * of the transactional mcontext. This way we have a backward-compatible
519 * MSR in the 'normal' (checkpointed) mcontext and additionally one can
520 * also look at what type of transaction (T or S) was active at the
521 * time of the signal.
522 */
523 if (__put_user((msr >> 32), &tm_frame->mc_gregs[PT_MSR]))
524 return 1;
525
526#ifdef CONFIG_ALTIVEC
527 /* save altivec registers */
528 if (current->thread.used_vr) {
529 if (__copy_to_user(&frame->mc_vregs, ¤t->thread.ckvr_state,
530 ELF_NVRREG * sizeof(vector128)))
531 return 1;
532 if (msr & MSR_VEC) {
533 if (__copy_to_user(&tm_frame->mc_vregs,
534 ¤t->thread.vr_state,
535 ELF_NVRREG * sizeof(vector128)))
536 return 1;
537 } else {
538 if (__copy_to_user(&tm_frame->mc_vregs,
539 ¤t->thread.ckvr_state,
540 ELF_NVRREG * sizeof(vector128)))
541 return 1;
542 }
543
544 /* set MSR_VEC in the saved MSR value to indicate that
545 * frame->mc_vregs contains valid data
546 */
547 msr |= MSR_VEC;
548 }
549
550 /* We always copy to/from vrsave, it's 0 if we don't have or don't
551 * use altivec. Since VSCR only contains 32 bits saved in the least
552 * significant bits of a vector, we "cheat" and stuff VRSAVE in the
553 * most significant bits of that same vector. --BenH
554 */
555 if (cpu_has_feature(CPU_FTR_ALTIVEC))
556 current->thread.ckvrsave = mfspr(SPRN_VRSAVE);
557 if (__put_user(current->thread.ckvrsave,
558 (u32 __user *)&frame->mc_vregs[32]))
559 return 1;
560 if (msr & MSR_VEC) {
561 if (__put_user(current->thread.vrsave,
562 (u32 __user *)&tm_frame->mc_vregs[32]))
563 return 1;
564 } else {
565 if (__put_user(current->thread.ckvrsave,
566 (u32 __user *)&tm_frame->mc_vregs[32]))
567 return 1;
568 }
569#endif /* CONFIG_ALTIVEC */
570
571 if (copy_ckfpr_to_user(&frame->mc_fregs, current))
572 return 1;
573 if (msr & MSR_FP) {
574 if (copy_fpr_to_user(&tm_frame->mc_fregs, current))
575 return 1;
576 } else {
577 if (copy_ckfpr_to_user(&tm_frame->mc_fregs, current))
578 return 1;
579 }
580
581#ifdef CONFIG_VSX
582 /*
583 * Copy VSR 0-31 upper half from thread_struct to local
584 * buffer, then write that to userspace. Also set MSR_VSX in
585 * the saved MSR value to indicate that frame->mc_vregs
586 * contains valid data
587 */
588 if (current->thread.used_vsr) {
589 if (copy_ckvsx_to_user(&frame->mc_vsregs, current))
590 return 1;
591 if (msr & MSR_VSX) {
592 if (copy_vsx_to_user(&tm_frame->mc_vsregs,
593 current))
594 return 1;
595 } else {
596 if (copy_ckvsx_to_user(&tm_frame->mc_vsregs, current))
597 return 1;
598 }
599
600 msr |= MSR_VSX;
601 }
602#endif /* CONFIG_VSX */
603#ifdef CONFIG_SPE
604 /* SPE regs are not checkpointed with TM, so this section is
605 * simply the same as in save_user_regs().
606 */
607 if (current->thread.used_spe) {
608 flush_spe_to_thread(current);
609 if (__copy_to_user(&frame->mc_vregs, current->thread.evr,
610 ELF_NEVRREG * sizeof(u32)))
611 return 1;
612 /* set MSR_SPE in the saved MSR value to indicate that
613 * frame->mc_vregs contains valid data */
614 msr |= MSR_SPE;
615 }
616
617 /* We always copy to/from spefscr */
618 if (__put_user(current->thread.spefscr, (u32 __user *)&frame->mc_vregs + ELF_NEVRREG))
619 return 1;
620#endif /* CONFIG_SPE */
621
622 if (__put_user(msr, &frame->mc_gregs[PT_MSR]))
623 return 1;
624 if (sigret) {
625 /* Set up the sigreturn trampoline: li r0,sigret; sc */
626 if (__put_user(0x38000000UL + sigret, &frame->tramp[0])
627 || __put_user(0x44000002UL, &frame->tramp[1]))
628 return 1;
629 flush_icache_range((unsigned long) &frame->tramp[0],
630 (unsigned long) &frame->tramp[2]);
631 }
632
633 return 0;
634}
635#endif
636
637/*
638 * Restore the current user register values from the user stack,
639 * (except for MSR).
640 */
641static long restore_user_regs(struct pt_regs *regs,
642 struct mcontext __user *sr, int sig)
643{
644 long err;
645 unsigned int save_r2 = 0;
646 unsigned long msr;
647#ifdef CONFIG_VSX
648 int i;
649#endif
650
651 /*
652 * restore general registers but not including MSR or SOFTE. Also
653 * take care of keeping r2 (TLS) intact if not a signal
654 */
655 if (!sig)
656 save_r2 = (unsigned int)regs->gpr[2];
657 err = restore_general_regs(regs, sr);
658 regs->trap = 0;
659 err |= __get_user(msr, &sr->mc_gregs[PT_MSR]);
660 if (!sig)
661 regs->gpr[2] = (unsigned long) save_r2;
662 if (err)
663 return 1;
664
665 /* if doing signal return, restore the previous little-endian mode */
666 if (sig)
667 regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE);
668
669#ifdef CONFIG_ALTIVEC
670 /*
671 * Force the process to reload the altivec registers from
672 * current->thread when it next does altivec instructions
673 */
674 regs->msr &= ~MSR_VEC;
675 if (msr & MSR_VEC) {
676 /* restore altivec registers from the stack */
677 if (__copy_from_user(¤t->thread.vr_state, &sr->mc_vregs,
678 sizeof(sr->mc_vregs)))
679 return 1;
680 current->thread.used_vr = true;
681 } else if (current->thread.used_vr)
682 memset(¤t->thread.vr_state, 0,
683 ELF_NVRREG * sizeof(vector128));
684
685 /* Always get VRSAVE back */
686 if (__get_user(current->thread.vrsave, (u32 __user *)&sr->mc_vregs[32]))
687 return 1;
688 if (cpu_has_feature(CPU_FTR_ALTIVEC))
689 mtspr(SPRN_VRSAVE, current->thread.vrsave);
690#endif /* CONFIG_ALTIVEC */
691 if (copy_fpr_from_user(current, &sr->mc_fregs))
692 return 1;
693
694#ifdef CONFIG_VSX
695 /*
696 * Force the process to reload the VSX registers from
697 * current->thread when it next does VSX instruction.
698 */
699 regs->msr &= ~MSR_VSX;
700 if (msr & MSR_VSX) {
701 /*
702 * Restore altivec registers from the stack to a local
703 * buffer, then write this out to the thread_struct
704 */
705 if (copy_vsx_from_user(current, &sr->mc_vsregs))
706 return 1;
707 current->thread.used_vsr = true;
708 } else if (current->thread.used_vsr)
709 for (i = 0; i < 32 ; i++)
710 current->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
711#endif /* CONFIG_VSX */
712 /*
713 * force the process to reload the FP registers from
714 * current->thread when it next does FP instructions
715 */
716 regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1);
717
718#ifdef CONFIG_SPE
719 /* force the process to reload the spe registers from
720 current->thread when it next does spe instructions */
721 regs->msr &= ~MSR_SPE;
722 if (msr & MSR_SPE) {
723 /* restore spe registers from the stack */
724 if (__copy_from_user(current->thread.evr, &sr->mc_vregs,
725 ELF_NEVRREG * sizeof(u32)))
726 return 1;
727 current->thread.used_spe = true;
728 } else if (current->thread.used_spe)
729 memset(current->thread.evr, 0, ELF_NEVRREG * sizeof(u32));
730
731 /* Always get SPEFSCR back */
732 if (__get_user(current->thread.spefscr, (u32 __user *)&sr->mc_vregs + ELF_NEVRREG))
733 return 1;
734#endif /* CONFIG_SPE */
735
736 return 0;
737}
738
739#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
740/*
741 * Restore the current user register values from the user stack, except for
742 * MSR, and recheckpoint the original checkpointed register state for processes
743 * in transactions.
744 */
745static long restore_tm_user_regs(struct pt_regs *regs,
746 struct mcontext __user *sr,
747 struct mcontext __user *tm_sr)
748{
749 long err;
750 unsigned long msr, msr_hi;
751#ifdef CONFIG_VSX
752 int i;
753#endif
754
755 if (tm_suspend_disabled)
756 return 1;
757 /*
758 * restore general registers but not including MSR or SOFTE. Also
759 * take care of keeping r2 (TLS) intact if not a signal.
760 * See comment in signal_64.c:restore_tm_sigcontexts();
761 * TFHAR is restored from the checkpointed NIP; TEXASR and TFIAR
762 * were set by the signal delivery.
763 */
764 err = restore_general_regs(regs, tm_sr);
765 err |= restore_general_regs(¤t->thread.ckpt_regs, sr);
766
767 err |= __get_user(current->thread.tm_tfhar, &sr->mc_gregs[PT_NIP]);
768
769 err |= __get_user(msr, &sr->mc_gregs[PT_MSR]);
770 if (err)
771 return 1;
772
773 /* Restore the previous little-endian mode */
774 regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE);
775
776#ifdef CONFIG_ALTIVEC
777 regs->msr &= ~MSR_VEC;
778 if (msr & MSR_VEC) {
779 /* restore altivec registers from the stack */
780 if (__copy_from_user(¤t->thread.ckvr_state, &sr->mc_vregs,
781 sizeof(sr->mc_vregs)) ||
782 __copy_from_user(¤t->thread.vr_state,
783 &tm_sr->mc_vregs,
784 sizeof(sr->mc_vregs)))
785 return 1;
786 current->thread.used_vr = true;
787 } else if (current->thread.used_vr) {
788 memset(¤t->thread.vr_state, 0,
789 ELF_NVRREG * sizeof(vector128));
790 memset(¤t->thread.ckvr_state, 0,
791 ELF_NVRREG * sizeof(vector128));
792 }
793
794 /* Always get VRSAVE back */
795 if (__get_user(current->thread.ckvrsave,
796 (u32 __user *)&sr->mc_vregs[32]) ||
797 __get_user(current->thread.vrsave,
798 (u32 __user *)&tm_sr->mc_vregs[32]))
799 return 1;
800 if (cpu_has_feature(CPU_FTR_ALTIVEC))
801 mtspr(SPRN_VRSAVE, current->thread.ckvrsave);
802#endif /* CONFIG_ALTIVEC */
803
804 regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1);
805
806 if (copy_fpr_from_user(current, &sr->mc_fregs) ||
807 copy_ckfpr_from_user(current, &tm_sr->mc_fregs))
808 return 1;
809
810#ifdef CONFIG_VSX
811 regs->msr &= ~MSR_VSX;
812 if (msr & MSR_VSX) {
813 /*
814 * Restore altivec registers from the stack to a local
815 * buffer, then write this out to the thread_struct
816 */
817 if (copy_vsx_from_user(current, &tm_sr->mc_vsregs) ||
818 copy_ckvsx_from_user(current, &sr->mc_vsregs))
819 return 1;
820 current->thread.used_vsr = true;
821 } else if (current->thread.used_vsr)
822 for (i = 0; i < 32 ; i++) {
823 current->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
824 current->thread.ckfp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
825 }
826#endif /* CONFIG_VSX */
827
828#ifdef CONFIG_SPE
829 /* SPE regs are not checkpointed with TM, so this section is
830 * simply the same as in restore_user_regs().
831 */
832 regs->msr &= ~MSR_SPE;
833 if (msr & MSR_SPE) {
834 if (__copy_from_user(current->thread.evr, &sr->mc_vregs,
835 ELF_NEVRREG * sizeof(u32)))
836 return 1;
837 current->thread.used_spe = true;
838 } else if (current->thread.used_spe)
839 memset(current->thread.evr, 0, ELF_NEVRREG * sizeof(u32));
840
841 /* Always get SPEFSCR back */
842 if (__get_user(current->thread.spefscr, (u32 __user *)&sr->mc_vregs
843 + ELF_NEVRREG))
844 return 1;
845#endif /* CONFIG_SPE */
846
847 /* Get the top half of the MSR from the user context */
848 if (__get_user(msr_hi, &tm_sr->mc_gregs[PT_MSR]))
849 return 1;
850 msr_hi <<= 32;
851 /* If TM bits are set to the reserved value, it's an invalid context */
852 if (MSR_TM_RESV(msr_hi))
853 return 1;
854 /* Pull in the MSR TM bits from the user context */
855 regs->msr = (regs->msr & ~MSR_TS_MASK) | (msr_hi & MSR_TS_MASK);
856 /* Now, recheckpoint. This loads up all of the checkpointed (older)
857 * registers, including FP and V[S]Rs. After recheckpointing, the
858 * transactional versions should be loaded.
859 */
860 tm_enable();
861 /* Make sure the transaction is marked as failed */
862 current->thread.tm_texasr |= TEXASR_FS;
863 /* This loads the checkpointed FP/VEC state, if used */
864 tm_recheckpoint(¤t->thread);
865
866 /* This loads the speculative FP/VEC state, if used */
867 msr_check_and_set(msr & (MSR_FP | MSR_VEC));
868 if (msr & MSR_FP) {
869 load_fp_state(¤t->thread.fp_state);
870 regs->msr |= (MSR_FP | current->thread.fpexc_mode);
871 }
872#ifdef CONFIG_ALTIVEC
873 if (msr & MSR_VEC) {
874 load_vr_state(¤t->thread.vr_state);
875 regs->msr |= MSR_VEC;
876 }
877#endif
878
879 return 0;
880}
881#endif
882
883#ifdef CONFIG_PPC64
884
885#define copy_siginfo_to_user copy_siginfo_to_user32
886
887#endif /* CONFIG_PPC64 */
888
889/*
890 * Set up a signal frame for a "real-time" signal handler
891 * (one which gets siginfo).
892 */
893int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
894 struct task_struct *tsk)
895{
896 struct rt_sigframe __user *rt_sf;
897 struct mcontext __user *frame;
898 struct mcontext __user *tm_frame = NULL;
899 void __user *addr;
900 unsigned long newsp = 0;
901 int sigret;
902 unsigned long tramp;
903 struct pt_regs *regs = tsk->thread.regs;
904
905 BUG_ON(tsk != current);
906
907 /* Set up Signal Frame */
908 /* Put a Real Time Context onto stack */
909 rt_sf = get_sigframe(ksig, get_tm_stackpointer(tsk), sizeof(*rt_sf), 1);
910 addr = rt_sf;
911 if (unlikely(rt_sf == NULL))
912 goto badframe;
913
914 /* Put the siginfo & fill in most of the ucontext */
915 if (copy_siginfo_to_user(&rt_sf->info, &ksig->info)
916 || __put_user(0, &rt_sf->uc.uc_flags)
917 || __save_altstack(&rt_sf->uc.uc_stack, regs->gpr[1])
918 || __put_user(to_user_ptr(&rt_sf->uc.uc_mcontext),
919 &rt_sf->uc.uc_regs)
920 || put_sigset_t(&rt_sf->uc.uc_sigmask, oldset))
921 goto badframe;
922
923 /* Save user registers on the stack */
924 frame = &rt_sf->uc.uc_mcontext;
925 addr = frame;
926 if (vdso32_rt_sigtramp && tsk->mm->context.vdso_base) {
927 sigret = 0;
928 tramp = tsk->mm->context.vdso_base + vdso32_rt_sigtramp;
929 } else {
930 sigret = __NR_rt_sigreturn;
931 tramp = (unsigned long) frame->tramp;
932 }
933
934#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
935 tm_frame = &rt_sf->uc_transact.uc_mcontext;
936 if (MSR_TM_ACTIVE(regs->msr)) {
937 if (__put_user((unsigned long)&rt_sf->uc_transact,
938 &rt_sf->uc.uc_link) ||
939 __put_user((unsigned long)tm_frame,
940 &rt_sf->uc_transact.uc_regs))
941 goto badframe;
942 if (save_tm_user_regs(regs, frame, tm_frame, sigret))
943 goto badframe;
944 }
945 else
946#endif
947 {
948 if (__put_user(0, &rt_sf->uc.uc_link))
949 goto badframe;
950 if (save_user_regs(regs, frame, tm_frame, sigret, 1))
951 goto badframe;
952 }
953 regs->link = tramp;
954
955 tsk->thread.fp_state.fpscr = 0; /* turn off all fp exceptions */
956
957 /* create a stack frame for the caller of the handler */
958 newsp = ((unsigned long)rt_sf) - (__SIGNAL_FRAMESIZE + 16);
959 addr = (void __user *)regs->gpr[1];
960 if (put_user(regs->gpr[1], (u32 __user *)newsp))
961 goto badframe;
962
963 /* Fill registers for signal handler */
964 regs->gpr[1] = newsp;
965 regs->gpr[3] = ksig->sig;
966 regs->gpr[4] = (unsigned long) &rt_sf->info;
967 regs->gpr[5] = (unsigned long) &rt_sf->uc;
968 regs->gpr[6] = (unsigned long) rt_sf;
969 regs->nip = (unsigned long) ksig->ka.sa.sa_handler;
970 /* enter the signal handler in native-endian mode */
971 regs->msr &= ~MSR_LE;
972 regs->msr |= (MSR_KERNEL & MSR_LE);
973 return 0;
974
975badframe:
976 if (show_unhandled_signals)
977 printk_ratelimited(KERN_INFO
978 "%s[%d]: bad frame in handle_rt_signal32: "
979 "%p nip %08lx lr %08lx\n",
980 tsk->comm, tsk->pid,
981 addr, regs->nip, regs->link);
982
983 return 1;
984}
985
986static int do_setcontext(struct ucontext __user *ucp, struct pt_regs *regs, int sig)
987{
988 sigset_t set;
989 struct mcontext __user *mcp;
990
991 if (get_sigset_t(&set, &ucp->uc_sigmask))
992 return -EFAULT;
993#ifdef CONFIG_PPC64
994 {
995 u32 cmcp;
996
997 if (__get_user(cmcp, &ucp->uc_regs))
998 return -EFAULT;
999 mcp = (struct mcontext __user *)(u64)cmcp;
1000 /* no need to check access_ok(mcp), since mcp < 4GB */
1001 }
1002#else
1003 if (__get_user(mcp, &ucp->uc_regs))
1004 return -EFAULT;
1005 if (!access_ok(VERIFY_READ, mcp, sizeof(*mcp)))
1006 return -EFAULT;
1007#endif
1008 set_current_blocked(&set);
1009 if (restore_user_regs(regs, mcp, sig))
1010 return -EFAULT;
1011
1012 return 0;
1013}
1014
1015#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1016static int do_setcontext_tm(struct ucontext __user *ucp,
1017 struct ucontext __user *tm_ucp,
1018 struct pt_regs *regs)
1019{
1020 sigset_t set;
1021 struct mcontext __user *mcp;
1022 struct mcontext __user *tm_mcp;
1023 u32 cmcp;
1024 u32 tm_cmcp;
1025
1026 if (get_sigset_t(&set, &ucp->uc_sigmask))
1027 return -EFAULT;
1028
1029 if (__get_user(cmcp, &ucp->uc_regs) ||
1030 __get_user(tm_cmcp, &tm_ucp->uc_regs))
1031 return -EFAULT;
1032 mcp = (struct mcontext __user *)(u64)cmcp;
1033 tm_mcp = (struct mcontext __user *)(u64)tm_cmcp;
1034 /* no need to check access_ok(mcp), since mcp < 4GB */
1035
1036 set_current_blocked(&set);
1037 if (restore_tm_user_regs(regs, mcp, tm_mcp))
1038 return -EFAULT;
1039
1040 return 0;
1041}
1042#endif
1043
1044long sys_swapcontext(struct ucontext __user *old_ctx,
1045 struct ucontext __user *new_ctx,
1046 int ctx_size, int r6, int r7, int r8, struct pt_regs *regs)
1047{
1048 unsigned char tmp __maybe_unused;
1049 int ctx_has_vsx_region = 0;
1050
1051#ifdef CONFIG_PPC64
1052 unsigned long new_msr = 0;
1053
1054 if (new_ctx) {
1055 struct mcontext __user *mcp;
1056 u32 cmcp;
1057
1058 /*
1059 * Get pointer to the real mcontext. No need for
1060 * access_ok since we are dealing with compat
1061 * pointers.
1062 */
1063 if (__get_user(cmcp, &new_ctx->uc_regs))
1064 return -EFAULT;
1065 mcp = (struct mcontext __user *)(u64)cmcp;
1066 if (__get_user(new_msr, &mcp->mc_gregs[PT_MSR]))
1067 return -EFAULT;
1068 }
1069 /*
1070 * Check that the context is not smaller than the original
1071 * size (with VMX but without VSX)
1072 */
1073 if (ctx_size < UCONTEXTSIZEWITHOUTVSX)
1074 return -EINVAL;
1075 /*
1076 * If the new context state sets the MSR VSX bits but
1077 * it doesn't provide VSX state.
1078 */
1079 if ((ctx_size < sizeof(struct ucontext)) &&
1080 (new_msr & MSR_VSX))
1081 return -EINVAL;
1082 /* Does the context have enough room to store VSX data? */
1083 if (ctx_size >= sizeof(struct ucontext))
1084 ctx_has_vsx_region = 1;
1085#else
1086 /* Context size is for future use. Right now, we only make sure
1087 * we are passed something we understand
1088 */
1089 if (ctx_size < sizeof(struct ucontext))
1090 return -EINVAL;
1091#endif
1092 if (old_ctx != NULL) {
1093 struct mcontext __user *mctx;
1094
1095 /*
1096 * old_ctx might not be 16-byte aligned, in which
1097 * case old_ctx->uc_mcontext won't be either.
1098 * Because we have the old_ctx->uc_pad2 field
1099 * before old_ctx->uc_mcontext, we need to round down
1100 * from &old_ctx->uc_mcontext to a 16-byte boundary.
1101 */
1102 mctx = (struct mcontext __user *)
1103 ((unsigned long) &old_ctx->uc_mcontext & ~0xfUL);
1104 if (!access_ok(VERIFY_WRITE, old_ctx, ctx_size)
1105 || save_user_regs(regs, mctx, NULL, 0, ctx_has_vsx_region)
1106 || put_sigset_t(&old_ctx->uc_sigmask, ¤t->blocked)
1107 || __put_user(to_user_ptr(mctx), &old_ctx->uc_regs))
1108 return -EFAULT;
1109 }
1110 if (new_ctx == NULL)
1111 return 0;
1112 if (!access_ok(VERIFY_READ, new_ctx, ctx_size)
1113 || __get_user(tmp, (u8 __user *) new_ctx)
1114 || __get_user(tmp, (u8 __user *) new_ctx + ctx_size - 1))
1115 return -EFAULT;
1116
1117 /*
1118 * If we get a fault copying the context into the kernel's
1119 * image of the user's registers, we can't just return -EFAULT
1120 * because the user's registers will be corrupted. For instance
1121 * the NIP value may have been updated but not some of the
1122 * other registers. Given that we have done the access_ok
1123 * and successfully read the first and last bytes of the region
1124 * above, this should only happen in an out-of-memory situation
1125 * or if another thread unmaps the region containing the context.
1126 * We kill the task with a SIGSEGV in this situation.
1127 */
1128 if (do_setcontext(new_ctx, regs, 0))
1129 do_exit(SIGSEGV);
1130
1131 set_thread_flag(TIF_RESTOREALL);
1132 return 0;
1133}
1134
1135long sys_rt_sigreturn(int r3, int r4, int r5, int r6, int r7, int r8,
1136 struct pt_regs *regs)
1137{
1138 struct rt_sigframe __user *rt_sf;
1139#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1140 struct ucontext __user *uc_transact;
1141 unsigned long msr_hi;
1142 unsigned long tmp;
1143 int tm_restore = 0;
1144#endif
1145 /* Always make any pending restarted system calls return -EINTR */
1146 current->restart_block.fn = do_no_restart_syscall;
1147
1148 rt_sf = (struct rt_sigframe __user *)
1149 (regs->gpr[1] + __SIGNAL_FRAMESIZE + 16);
1150 if (!access_ok(VERIFY_READ, rt_sf, sizeof(*rt_sf)))
1151 goto bad;
1152
1153#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1154 /*
1155 * If there is a transactional state then throw it away.
1156 * The purpose of a sigreturn is to destroy all traces of the
1157 * signal frame, this includes any transactional state created
1158 * within in. We only check for suspended as we can never be
1159 * active in the kernel, we are active, there is nothing better to
1160 * do than go ahead and Bad Thing later.
1161 * The cause is not important as there will never be a
1162 * recheckpoint so it's not user visible.
1163 */
1164 if (MSR_TM_SUSPENDED(mfmsr()))
1165 tm_reclaim_current(0);
1166
1167 if (__get_user(tmp, &rt_sf->uc.uc_link))
1168 goto bad;
1169 uc_transact = (struct ucontext __user *)(uintptr_t)tmp;
1170 if (uc_transact) {
1171 u32 cmcp;
1172 struct mcontext __user *mcp;
1173
1174 if (__get_user(cmcp, &uc_transact->uc_regs))
1175 return -EFAULT;
1176 mcp = (struct mcontext __user *)(u64)cmcp;
1177 /* The top 32 bits of the MSR are stashed in the transactional
1178 * ucontext. */
1179 if (__get_user(msr_hi, &mcp->mc_gregs[PT_MSR]))
1180 goto bad;
1181
1182 if (MSR_TM_ACTIVE(msr_hi<<32)) {
1183 /* We only recheckpoint on return if we're
1184 * transaction.
1185 */
1186 tm_restore = 1;
1187 if (do_setcontext_tm(&rt_sf->uc, uc_transact, regs))
1188 goto bad;
1189 }
1190 }
1191 if (!tm_restore)
1192 /* Fall through, for non-TM restore */
1193#endif
1194 if (do_setcontext(&rt_sf->uc, regs, 1))
1195 goto bad;
1196
1197 /*
1198 * It's not clear whether or why it is desirable to save the
1199 * sigaltstack setting on signal delivery and restore it on
1200 * signal return. But other architectures do this and we have
1201 * always done it up until now so it is probably better not to
1202 * change it. -- paulus
1203 */
1204#ifdef CONFIG_PPC64
1205 if (compat_restore_altstack(&rt_sf->uc.uc_stack))
1206 goto bad;
1207#else
1208 if (restore_altstack(&rt_sf->uc.uc_stack))
1209 goto bad;
1210#endif
1211 set_thread_flag(TIF_RESTOREALL);
1212 return 0;
1213
1214 bad:
1215 if (show_unhandled_signals)
1216 printk_ratelimited(KERN_INFO
1217 "%s[%d]: bad frame in sys_rt_sigreturn: "
1218 "%p nip %08lx lr %08lx\n",
1219 current->comm, current->pid,
1220 rt_sf, regs->nip, regs->link);
1221
1222 force_sig(SIGSEGV, current);
1223 return 0;
1224}
1225
1226#ifdef CONFIG_PPC32
1227int sys_debug_setcontext(struct ucontext __user *ctx,
1228 int ndbg, struct sig_dbg_op __user *dbg,
1229 int r6, int r7, int r8,
1230 struct pt_regs *regs)
1231{
1232 struct sig_dbg_op op;
1233 int i;
1234 unsigned char tmp __maybe_unused;
1235 unsigned long new_msr = regs->msr;
1236#ifdef CONFIG_PPC_ADV_DEBUG_REGS
1237 unsigned long new_dbcr0 = current->thread.debug.dbcr0;
1238#endif
1239
1240 for (i=0; i<ndbg; i++) {
1241 if (copy_from_user(&op, dbg + i, sizeof(op)))
1242 return -EFAULT;
1243 switch (op.dbg_type) {
1244 case SIG_DBG_SINGLE_STEPPING:
1245#ifdef CONFIG_PPC_ADV_DEBUG_REGS
1246 if (op.dbg_value) {
1247 new_msr |= MSR_DE;
1248 new_dbcr0 |= (DBCR0_IDM | DBCR0_IC);
1249 } else {
1250 new_dbcr0 &= ~DBCR0_IC;
1251 if (!DBCR_ACTIVE_EVENTS(new_dbcr0,
1252 current->thread.debug.dbcr1)) {
1253 new_msr &= ~MSR_DE;
1254 new_dbcr0 &= ~DBCR0_IDM;
1255 }
1256 }
1257#else
1258 if (op.dbg_value)
1259 new_msr |= MSR_SE;
1260 else
1261 new_msr &= ~MSR_SE;
1262#endif
1263 break;
1264 case SIG_DBG_BRANCH_TRACING:
1265#ifdef CONFIG_PPC_ADV_DEBUG_REGS
1266 return -EINVAL;
1267#else
1268 if (op.dbg_value)
1269 new_msr |= MSR_BE;
1270 else
1271 new_msr &= ~MSR_BE;
1272#endif
1273 break;
1274
1275 default:
1276 return -EINVAL;
1277 }
1278 }
1279
1280 /* We wait until here to actually install the values in the
1281 registers so if we fail in the above loop, it will not
1282 affect the contents of these registers. After this point,
1283 failure is a problem, anyway, and it's very unlikely unless
1284 the user is really doing something wrong. */
1285 regs->msr = new_msr;
1286#ifdef CONFIG_PPC_ADV_DEBUG_REGS
1287 current->thread.debug.dbcr0 = new_dbcr0;
1288#endif
1289
1290 if (!access_ok(VERIFY_READ, ctx, sizeof(*ctx))
1291 || __get_user(tmp, (u8 __user *) ctx)
1292 || __get_user(tmp, (u8 __user *) (ctx + 1) - 1))
1293 return -EFAULT;
1294
1295 /*
1296 * If we get a fault copying the context into the kernel's
1297 * image of the user's registers, we can't just return -EFAULT
1298 * because the user's registers will be corrupted. For instance
1299 * the NIP value may have been updated but not some of the
1300 * other registers. Given that we have done the access_ok
1301 * and successfully read the first and last bytes of the region
1302 * above, this should only happen in an out-of-memory situation
1303 * or if another thread unmaps the region containing the context.
1304 * We kill the task with a SIGSEGV in this situation.
1305 */
1306 if (do_setcontext(ctx, regs, 1)) {
1307 if (show_unhandled_signals)
1308 printk_ratelimited(KERN_INFO "%s[%d]: bad frame in "
1309 "sys_debug_setcontext: %p nip %08lx "
1310 "lr %08lx\n",
1311 current->comm, current->pid,
1312 ctx, regs->nip, regs->link);
1313
1314 force_sig(SIGSEGV, current);
1315 goto out;
1316 }
1317
1318 /*
1319 * It's not clear whether or why it is desirable to save the
1320 * sigaltstack setting on signal delivery and restore it on
1321 * signal return. But other architectures do this and we have
1322 * always done it up until now so it is probably better not to
1323 * change it. -- paulus
1324 */
1325 restore_altstack(&ctx->uc_stack);
1326
1327 set_thread_flag(TIF_RESTOREALL);
1328 out:
1329 return 0;
1330}
1331#endif
1332
1333/*
1334 * OK, we're invoking a handler
1335 */
1336int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
1337 struct task_struct *tsk)
1338{
1339 struct sigcontext __user *sc;
1340 struct sigframe __user *frame;
1341 struct mcontext __user *tm_mctx = NULL;
1342 unsigned long newsp = 0;
1343 int sigret;
1344 unsigned long tramp;
1345 struct pt_regs *regs = tsk->thread.regs;
1346
1347 BUG_ON(tsk != current);
1348
1349 /* Set up Signal Frame */
1350 frame = get_sigframe(ksig, get_tm_stackpointer(tsk), sizeof(*frame), 1);
1351 if (unlikely(frame == NULL))
1352 goto badframe;
1353 sc = (struct sigcontext __user *) &frame->sctx;
1354
1355#if _NSIG != 64
1356#error "Please adjust handle_signal()"
1357#endif
1358 if (__put_user(to_user_ptr(ksig->ka.sa.sa_handler), &sc->handler)
1359 || __put_user(oldset->sig[0], &sc->oldmask)
1360#ifdef CONFIG_PPC64
1361 || __put_user((oldset->sig[0] >> 32), &sc->_unused[3])
1362#else
1363 || __put_user(oldset->sig[1], &sc->_unused[3])
1364#endif
1365 || __put_user(to_user_ptr(&frame->mctx), &sc->regs)
1366 || __put_user(ksig->sig, &sc->signal))
1367 goto badframe;
1368
1369 if (vdso32_sigtramp && tsk->mm->context.vdso_base) {
1370 sigret = 0;
1371 tramp = tsk->mm->context.vdso_base + vdso32_sigtramp;
1372 } else {
1373 sigret = __NR_sigreturn;
1374 tramp = (unsigned long) frame->mctx.tramp;
1375 }
1376
1377#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1378 tm_mctx = &frame->mctx_transact;
1379 if (MSR_TM_ACTIVE(regs->msr)) {
1380 if (save_tm_user_regs(regs, &frame->mctx, &frame->mctx_transact,
1381 sigret))
1382 goto badframe;
1383 }
1384 else
1385#endif
1386 {
1387 if (save_user_regs(regs, &frame->mctx, tm_mctx, sigret, 1))
1388 goto badframe;
1389 }
1390
1391 regs->link = tramp;
1392
1393 tsk->thread.fp_state.fpscr = 0; /* turn off all fp exceptions */
1394
1395 /* create a stack frame for the caller of the handler */
1396 newsp = ((unsigned long)frame) - __SIGNAL_FRAMESIZE;
1397 if (put_user(regs->gpr[1], (u32 __user *)newsp))
1398 goto badframe;
1399
1400 regs->gpr[1] = newsp;
1401 regs->gpr[3] = ksig->sig;
1402 regs->gpr[4] = (unsigned long) sc;
1403 regs->nip = (unsigned long) (unsigned long)ksig->ka.sa.sa_handler;
1404 /* enter the signal handler in big-endian mode */
1405 regs->msr &= ~MSR_LE;
1406 return 0;
1407
1408badframe:
1409 if (show_unhandled_signals)
1410 printk_ratelimited(KERN_INFO
1411 "%s[%d]: bad frame in handle_signal32: "
1412 "%p nip %08lx lr %08lx\n",
1413 tsk->comm, tsk->pid,
1414 frame, regs->nip, regs->link);
1415
1416 return 1;
1417}
1418
1419/*
1420 * Do a signal return; undo the signal stack.
1421 */
1422long sys_sigreturn(int r3, int r4, int r5, int r6, int r7, int r8,
1423 struct pt_regs *regs)
1424{
1425 struct sigframe __user *sf;
1426 struct sigcontext __user *sc;
1427 struct sigcontext sigctx;
1428 struct mcontext __user *sr;
1429 void __user *addr;
1430 sigset_t set;
1431#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1432 struct mcontext __user *mcp, *tm_mcp;
1433 unsigned long msr_hi;
1434#endif
1435
1436 /* Always make any pending restarted system calls return -EINTR */
1437 current->restart_block.fn = do_no_restart_syscall;
1438
1439 sf = (struct sigframe __user *)(regs->gpr[1] + __SIGNAL_FRAMESIZE);
1440 sc = &sf->sctx;
1441 addr = sc;
1442 if (copy_from_user(&sigctx, sc, sizeof(sigctx)))
1443 goto badframe;
1444
1445#ifdef CONFIG_PPC64
1446 /*
1447 * Note that PPC32 puts the upper 32 bits of the sigmask in the
1448 * unused part of the signal stackframe
1449 */
1450 set.sig[0] = sigctx.oldmask + ((long)(sigctx._unused[3]) << 32);
1451#else
1452 set.sig[0] = sigctx.oldmask;
1453 set.sig[1] = sigctx._unused[3];
1454#endif
1455 set_current_blocked(&set);
1456
1457#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1458 mcp = (struct mcontext __user *)&sf->mctx;
1459 tm_mcp = (struct mcontext __user *)&sf->mctx_transact;
1460 if (__get_user(msr_hi, &tm_mcp->mc_gregs[PT_MSR]))
1461 goto badframe;
1462 if (MSR_TM_ACTIVE(msr_hi<<32)) {
1463 if (!cpu_has_feature(CPU_FTR_TM))
1464 goto badframe;
1465 if (restore_tm_user_regs(regs, mcp, tm_mcp))
1466 goto badframe;
1467 } else
1468#endif
1469 {
1470 sr = (struct mcontext __user *)from_user_ptr(sigctx.regs);
1471 addr = sr;
1472 if (!access_ok(VERIFY_READ, sr, sizeof(*sr))
1473 || restore_user_regs(regs, sr, 1))
1474 goto badframe;
1475 }
1476
1477 set_thread_flag(TIF_RESTOREALL);
1478 return 0;
1479
1480badframe:
1481 if (show_unhandled_signals)
1482 printk_ratelimited(KERN_INFO
1483 "%s[%d]: bad frame in sys_sigreturn: "
1484 "%p nip %08lx lr %08lx\n",
1485 current->comm, current->pid,
1486 addr, regs->nip, regs->link);
1487
1488 force_sig(SIGSEGV, current);
1489 return 0;
1490}
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Signal handling for 32bit PPC and 32bit tasks on 64bit PPC
4 *
5 * PowerPC version
6 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
7 * Copyright (C) 2001 IBM
8 * Copyright (C) 1997,1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
9 * Copyright (C) 1997 David S. Miller (davem@caip.rutgers.edu)
10 *
11 * Derived from "arch/i386/kernel/signal.c"
12 * Copyright (C) 1991, 1992 Linus Torvalds
13 * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
14 */
15
16#include <linux/sched.h>
17#include <linux/mm.h>
18#include <linux/smp.h>
19#include <linux/kernel.h>
20#include <linux/signal.h>
21#include <linux/errno.h>
22#include <linux/elf.h>
23#include <linux/ptrace.h>
24#include <linux/pagemap.h>
25#include <linux/ratelimit.h>
26#include <linux/syscalls.h>
27#ifdef CONFIG_PPC64
28#include <linux/compat.h>
29#else
30#include <linux/wait.h>
31#include <linux/unistd.h>
32#include <linux/stddef.h>
33#include <linux/tty.h>
34#include <linux/binfmts.h>
35#endif
36
37#include <linux/uaccess.h>
38#include <asm/cacheflush.h>
39#include <asm/syscalls.h>
40#include <asm/sigcontext.h>
41#include <asm/vdso.h>
42#include <asm/switch_to.h>
43#include <asm/tm.h>
44#include <asm/asm-prototypes.h>
45#ifdef CONFIG_PPC64
46#include "ppc32.h"
47#include <asm/unistd.h>
48#else
49#include <asm/ucontext.h>
50#endif
51
52#include "signal.h"
53
54
55#ifdef CONFIG_PPC64
56#define old_sigaction old_sigaction32
57#define sigcontext sigcontext32
58#define mcontext mcontext32
59#define ucontext ucontext32
60
61/*
62 * Userspace code may pass a ucontext which doesn't include VSX added
63 * at the end. We need to check for this case.
64 */
65#define UCONTEXTSIZEWITHOUTVSX \
66 (sizeof(struct ucontext) - sizeof(elf_vsrreghalf_t32))
67
68/*
69 * Returning 0 means we return to userspace via
70 * ret_from_except and thus restore all user
71 * registers from *regs. This is what we need
72 * to do when a signal has been delivered.
73 */
74
75#define GP_REGS_SIZE min(sizeof(elf_gregset_t32), sizeof(struct pt_regs32))
76#undef __SIGNAL_FRAMESIZE
77#define __SIGNAL_FRAMESIZE __SIGNAL_FRAMESIZE32
78#undef ELF_NVRREG
79#define ELF_NVRREG ELF_NVRREG32
80
81/*
82 * Functions for flipping sigsets (thanks to brain dead generic
83 * implementation that makes things simple for little endian only)
84 */
85#define unsafe_put_sigset_t unsafe_put_compat_sigset
86#define unsafe_get_sigset_t unsafe_get_compat_sigset
87
88#define to_user_ptr(p) ptr_to_compat(p)
89#define from_user_ptr(p) compat_ptr(p)
90
91static __always_inline int
92__unsafe_save_general_regs(struct pt_regs *regs, struct mcontext __user *frame)
93{
94 elf_greg_t64 *gregs = (elf_greg_t64 *)regs;
95 int val, i;
96
97 for (i = 0; i <= PT_RESULT; i ++) {
98 /* Force usr to alway see softe as 1 (interrupts enabled) */
99 if (i == PT_SOFTE)
100 val = 1;
101 else
102 val = gregs[i];
103
104 unsafe_put_user(val, &frame->mc_gregs[i], failed);
105 }
106 return 0;
107
108failed:
109 return 1;
110}
111
112static __always_inline int
113__unsafe_restore_general_regs(struct pt_regs *regs, struct mcontext __user *sr)
114{
115 elf_greg_t64 *gregs = (elf_greg_t64 *)regs;
116 int i;
117
118 for (i = 0; i <= PT_RESULT; i++) {
119 if ((i == PT_MSR) || (i == PT_SOFTE))
120 continue;
121 unsafe_get_user(gregs[i], &sr->mc_gregs[i], failed);
122 }
123 return 0;
124
125failed:
126 return 1;
127}
128
129#else /* CONFIG_PPC64 */
130
131#define GP_REGS_SIZE min(sizeof(elf_gregset_t), sizeof(struct pt_regs))
132
133#define unsafe_put_sigset_t(uset, set, label) do { \
134 sigset_t __user *__us = uset ; \
135 const sigset_t *__s = set; \
136 \
137 unsafe_copy_to_user(__us, __s, sizeof(*__us), label); \
138} while (0)
139
140#define unsafe_get_sigset_t unsafe_get_user_sigset
141
142#define to_user_ptr(p) ((unsigned long)(p))
143#define from_user_ptr(p) ((void __user *)(p))
144
145static __always_inline int
146__unsafe_save_general_regs(struct pt_regs *regs, struct mcontext __user *frame)
147{
148 unsafe_copy_to_user(&frame->mc_gregs, regs, GP_REGS_SIZE, failed);
149 return 0;
150
151failed:
152 return 1;
153}
154
155static __always_inline
156int __unsafe_restore_general_regs(struct pt_regs *regs, struct mcontext __user *sr)
157{
158 /* copy up to but not including MSR */
159 unsafe_copy_from_user(regs, &sr->mc_gregs, PT_MSR * sizeof(elf_greg_t), failed);
160
161 /* copy from orig_r3 (the word after the MSR) up to the end */
162 unsafe_copy_from_user(®s->orig_gpr3, &sr->mc_gregs[PT_ORIG_R3],
163 GP_REGS_SIZE - PT_ORIG_R3 * sizeof(elf_greg_t), failed);
164
165 return 0;
166
167failed:
168 return 1;
169}
170#endif
171
172#define unsafe_save_general_regs(regs, frame, label) do { \
173 if (__unsafe_save_general_regs(regs, frame)) \
174 goto label; \
175} while (0)
176
177#define unsafe_restore_general_regs(regs, frame, label) do { \
178 if (__unsafe_restore_general_regs(regs, frame)) \
179 goto label; \
180} while (0)
181
182/*
183 * When we have signals to deliver, we set up on the
184 * user stack, going down from the original stack pointer:
185 * an ABI gap of 56 words
186 * an mcontext struct
187 * a sigcontext struct
188 * a gap of __SIGNAL_FRAMESIZE bytes
189 *
190 * Each of these things must be a multiple of 16 bytes in size. The following
191 * structure represent all of this except the __SIGNAL_FRAMESIZE gap
192 *
193 */
194struct sigframe {
195 struct sigcontext sctx; /* the sigcontext */
196 struct mcontext mctx; /* all the register values */
197#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
198 struct sigcontext sctx_transact;
199 struct mcontext mctx_transact;
200#endif
201 /*
202 * Programs using the rs6000/xcoff abi can save up to 19 gp
203 * regs and 18 fp regs below sp before decrementing it.
204 */
205 int abigap[56];
206};
207
208/*
209 * When we have rt signals to deliver, we set up on the
210 * user stack, going down from the original stack pointer:
211 * one rt_sigframe struct (siginfo + ucontext + ABI gap)
212 * a gap of __SIGNAL_FRAMESIZE+16 bytes
213 * (the +16 is to get the siginfo and ucontext in the same
214 * positions as in older kernels).
215 *
216 * Each of these things must be a multiple of 16 bytes in size.
217 *
218 */
219struct rt_sigframe {
220#ifdef CONFIG_PPC64
221 compat_siginfo_t info;
222#else
223 struct siginfo info;
224#endif
225 struct ucontext uc;
226#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
227 struct ucontext uc_transact;
228#endif
229 /*
230 * Programs using the rs6000/xcoff abi can save up to 19 gp
231 * regs and 18 fp regs below sp before decrementing it.
232 */
233 int abigap[56];
234};
235
236/*
237 * Save the current user registers on the user stack.
238 * We only save the altivec/spe registers if the process has used
239 * altivec/spe instructions at some point.
240 */
241static void prepare_save_user_regs(int ctx_has_vsx_region)
242{
243 /* Make sure floating point registers are stored in regs */
244 flush_fp_to_thread(current);
245#ifdef CONFIG_ALTIVEC
246 if (current->thread.used_vr)
247 flush_altivec_to_thread(current);
248 if (cpu_has_feature(CPU_FTR_ALTIVEC))
249 current->thread.vrsave = mfspr(SPRN_VRSAVE);
250#endif
251#ifdef CONFIG_VSX
252 if (current->thread.used_vsr && ctx_has_vsx_region)
253 flush_vsx_to_thread(current);
254#endif
255#ifdef CONFIG_SPE
256 if (current->thread.used_spe)
257 flush_spe_to_thread(current);
258#endif
259}
260
261static int __unsafe_save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
262 struct mcontext __user *tm_frame, int ctx_has_vsx_region)
263{
264 unsigned long msr = regs->msr;
265
266 /* save general registers */
267 unsafe_save_general_regs(regs, frame, failed);
268
269#ifdef CONFIG_ALTIVEC
270 /* save altivec registers */
271 if (current->thread.used_vr) {
272 unsafe_copy_to_user(&frame->mc_vregs, ¤t->thread.vr_state,
273 ELF_NVRREG * sizeof(vector128), failed);
274 /* set MSR_VEC in the saved MSR value to indicate that
275 frame->mc_vregs contains valid data */
276 msr |= MSR_VEC;
277 }
278 /* else assert((regs->msr & MSR_VEC) == 0) */
279
280 /* We always copy to/from vrsave, it's 0 if we don't have or don't
281 * use altivec. Since VSCR only contains 32 bits saved in the least
282 * significant bits of a vector, we "cheat" and stuff VRSAVE in the
283 * most significant bits of that same vector. --BenH
284 * Note that the current VRSAVE value is in the SPR at this point.
285 */
286 unsafe_put_user(current->thread.vrsave, (u32 __user *)&frame->mc_vregs[32],
287 failed);
288#endif /* CONFIG_ALTIVEC */
289 unsafe_copy_fpr_to_user(&frame->mc_fregs, current, failed);
290
291 /*
292 * Clear the MSR VSX bit to indicate there is no valid state attached
293 * to this context, except in the specific case below where we set it.
294 */
295 msr &= ~MSR_VSX;
296#ifdef CONFIG_VSX
297 /*
298 * Copy VSR 0-31 upper half from thread_struct to local
299 * buffer, then write that to userspace. Also set MSR_VSX in
300 * the saved MSR value to indicate that frame->mc_vregs
301 * contains valid data
302 */
303 if (current->thread.used_vsr && ctx_has_vsx_region) {
304 unsafe_copy_vsx_to_user(&frame->mc_vsregs, current, failed);
305 msr |= MSR_VSX;
306 }
307#endif /* CONFIG_VSX */
308#ifdef CONFIG_SPE
309 /* save spe registers */
310 if (current->thread.used_spe) {
311 unsafe_copy_to_user(&frame->mc_vregs, current->thread.evr,
312 ELF_NEVRREG * sizeof(u32), failed);
313 /* set MSR_SPE in the saved MSR value to indicate that
314 frame->mc_vregs contains valid data */
315 msr |= MSR_SPE;
316 }
317 /* else assert((regs->msr & MSR_SPE) == 0) */
318
319 /* We always copy to/from spefscr */
320 unsafe_put_user(current->thread.spefscr,
321 (u32 __user *)&frame->mc_vregs + ELF_NEVRREG, failed);
322#endif /* CONFIG_SPE */
323
324 unsafe_put_user(msr, &frame->mc_gregs[PT_MSR], failed);
325
326 /* We need to write 0 the MSR top 32 bits in the tm frame so that we
327 * can check it on the restore to see if TM is active
328 */
329 if (tm_frame)
330 unsafe_put_user(0, &tm_frame->mc_gregs[PT_MSR], failed);
331
332 return 0;
333
334failed:
335 return 1;
336}
337
338#define unsafe_save_user_regs(regs, frame, tm_frame, has_vsx, label) do { \
339 if (__unsafe_save_user_regs(regs, frame, tm_frame, has_vsx)) \
340 goto label; \
341} while (0)
342
343#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
344/*
345 * Save the current user registers on the user stack.
346 * We only save the altivec/spe registers if the process has used
347 * altivec/spe instructions at some point.
348 * We also save the transactional registers to a second ucontext in the
349 * frame.
350 *
351 * See __unsafe_save_user_regs() and signal_64.c:setup_tm_sigcontexts().
352 */
353static void prepare_save_tm_user_regs(void)
354{
355 WARN_ON(tm_suspend_disabled);
356
357 if (cpu_has_feature(CPU_FTR_ALTIVEC))
358 current->thread.ckvrsave = mfspr(SPRN_VRSAVE);
359}
360
361static int save_tm_user_regs_unsafe(struct pt_regs *regs, struct mcontext __user *frame,
362 struct mcontext __user *tm_frame, unsigned long msr)
363{
364 /* Save both sets of general registers */
365 unsafe_save_general_regs(¤t->thread.ckpt_regs, frame, failed);
366 unsafe_save_general_regs(regs, tm_frame, failed);
367
368 /* Stash the top half of the 64bit MSR into the 32bit MSR word
369 * of the transactional mcontext. This way we have a backward-compatible
370 * MSR in the 'normal' (checkpointed) mcontext and additionally one can
371 * also look at what type of transaction (T or S) was active at the
372 * time of the signal.
373 */
374 unsafe_put_user((msr >> 32), &tm_frame->mc_gregs[PT_MSR], failed);
375
376 /* save altivec registers */
377 if (current->thread.used_vr) {
378 unsafe_copy_to_user(&frame->mc_vregs, ¤t->thread.ckvr_state,
379 ELF_NVRREG * sizeof(vector128), failed);
380 if (msr & MSR_VEC)
381 unsafe_copy_to_user(&tm_frame->mc_vregs,
382 ¤t->thread.vr_state,
383 ELF_NVRREG * sizeof(vector128), failed);
384 else
385 unsafe_copy_to_user(&tm_frame->mc_vregs,
386 ¤t->thread.ckvr_state,
387 ELF_NVRREG * sizeof(vector128), failed);
388
389 /* set MSR_VEC in the saved MSR value to indicate that
390 * frame->mc_vregs contains valid data
391 */
392 msr |= MSR_VEC;
393 }
394
395 /* We always copy to/from vrsave, it's 0 if we don't have or don't
396 * use altivec. Since VSCR only contains 32 bits saved in the least
397 * significant bits of a vector, we "cheat" and stuff VRSAVE in the
398 * most significant bits of that same vector. --BenH
399 */
400 unsafe_put_user(current->thread.ckvrsave,
401 (u32 __user *)&frame->mc_vregs[32], failed);
402 if (msr & MSR_VEC)
403 unsafe_put_user(current->thread.vrsave,
404 (u32 __user *)&tm_frame->mc_vregs[32], failed);
405 else
406 unsafe_put_user(current->thread.ckvrsave,
407 (u32 __user *)&tm_frame->mc_vregs[32], failed);
408
409 unsafe_copy_ckfpr_to_user(&frame->mc_fregs, current, failed);
410 if (msr & MSR_FP)
411 unsafe_copy_fpr_to_user(&tm_frame->mc_fregs, current, failed);
412 else
413 unsafe_copy_ckfpr_to_user(&tm_frame->mc_fregs, current, failed);
414
415 /*
416 * Copy VSR 0-31 upper half from thread_struct to local
417 * buffer, then write that to userspace. Also set MSR_VSX in
418 * the saved MSR value to indicate that frame->mc_vregs
419 * contains valid data
420 */
421 if (current->thread.used_vsr) {
422 unsafe_copy_ckvsx_to_user(&frame->mc_vsregs, current, failed);
423 if (msr & MSR_VSX)
424 unsafe_copy_vsx_to_user(&tm_frame->mc_vsregs, current, failed);
425 else
426 unsafe_copy_ckvsx_to_user(&tm_frame->mc_vsregs, current, failed);
427
428 msr |= MSR_VSX;
429 }
430
431 unsafe_put_user(msr, &frame->mc_gregs[PT_MSR], failed);
432
433 return 0;
434
435failed:
436 return 1;
437}
438#else
439static void prepare_save_tm_user_regs(void) { }
440
441static int save_tm_user_regs_unsafe(struct pt_regs *regs, struct mcontext __user *frame,
442 struct mcontext __user *tm_frame, unsigned long msr)
443{
444 return 0;
445}
446#endif
447
448#define unsafe_save_tm_user_regs(regs, frame, tm_frame, msr, label) do { \
449 if (save_tm_user_regs_unsafe(regs, frame, tm_frame, msr)) \
450 goto label; \
451} while (0)
452
453/*
454 * Restore the current user register values from the user stack,
455 * (except for MSR).
456 */
457static long restore_user_regs(struct pt_regs *regs,
458 struct mcontext __user *sr, int sig)
459{
460 unsigned int save_r2 = 0;
461 unsigned long msr;
462#ifdef CONFIG_VSX
463 int i;
464#endif
465
466 if (!user_read_access_begin(sr, sizeof(*sr)))
467 return 1;
468 /*
469 * restore general registers but not including MSR or SOFTE. Also
470 * take care of keeping r2 (TLS) intact if not a signal
471 */
472 if (!sig)
473 save_r2 = (unsigned int)regs->gpr[2];
474 unsafe_restore_general_regs(regs, sr, failed);
475 set_trap_norestart(regs);
476 unsafe_get_user(msr, &sr->mc_gregs[PT_MSR], failed);
477 if (!sig)
478 regs->gpr[2] = (unsigned long) save_r2;
479
480 /* if doing signal return, restore the previous little-endian mode */
481 if (sig)
482 regs_set_return_msr(regs, (regs->msr & ~MSR_LE) | (msr & MSR_LE));
483
484#ifdef CONFIG_ALTIVEC
485 /*
486 * Force the process to reload the altivec registers from
487 * current->thread when it next does altivec instructions
488 */
489 regs_set_return_msr(regs, regs->msr & ~MSR_VEC);
490 if (msr & MSR_VEC) {
491 /* restore altivec registers from the stack */
492 unsafe_copy_from_user(¤t->thread.vr_state, &sr->mc_vregs,
493 sizeof(sr->mc_vregs), failed);
494 current->thread.used_vr = true;
495 } else if (current->thread.used_vr)
496 memset(¤t->thread.vr_state, 0,
497 ELF_NVRREG * sizeof(vector128));
498
499 /* Always get VRSAVE back */
500 unsafe_get_user(current->thread.vrsave, (u32 __user *)&sr->mc_vregs[32], failed);
501 if (cpu_has_feature(CPU_FTR_ALTIVEC))
502 mtspr(SPRN_VRSAVE, current->thread.vrsave);
503#endif /* CONFIG_ALTIVEC */
504 unsafe_copy_fpr_from_user(current, &sr->mc_fregs, failed);
505
506#ifdef CONFIG_VSX
507 /*
508 * Force the process to reload the VSX registers from
509 * current->thread when it next does VSX instruction.
510 */
511 regs_set_return_msr(regs, regs->msr & ~MSR_VSX);
512 if (msr & MSR_VSX) {
513 /*
514 * Restore altivec registers from the stack to a local
515 * buffer, then write this out to the thread_struct
516 */
517 unsafe_copy_vsx_from_user(current, &sr->mc_vsregs, failed);
518 current->thread.used_vsr = true;
519 } else if (current->thread.used_vsr)
520 for (i = 0; i < 32 ; i++)
521 current->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
522#endif /* CONFIG_VSX */
523 /*
524 * force the process to reload the FP registers from
525 * current->thread when it next does FP instructions
526 */
527 regs_set_return_msr(regs, regs->msr & ~(MSR_FP | MSR_FE0 | MSR_FE1));
528
529#ifdef CONFIG_SPE
530 /* force the process to reload the spe registers from
531 current->thread when it next does spe instructions */
532 regs_set_return_msr(regs, regs->msr & ~MSR_SPE);
533 if (msr & MSR_SPE) {
534 /* restore spe registers from the stack */
535 unsafe_copy_from_user(current->thread.evr, &sr->mc_vregs,
536 ELF_NEVRREG * sizeof(u32), failed);
537 current->thread.used_spe = true;
538 } else if (current->thread.used_spe)
539 memset(current->thread.evr, 0, ELF_NEVRREG * sizeof(u32));
540
541 /* Always get SPEFSCR back */
542 unsafe_get_user(current->thread.spefscr, (u32 __user *)&sr->mc_vregs + ELF_NEVRREG, failed);
543#endif /* CONFIG_SPE */
544
545 user_read_access_end();
546 return 0;
547
548failed:
549 user_read_access_end();
550 return 1;
551}
552
553#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
554/*
555 * Restore the current user register values from the user stack, except for
556 * MSR, and recheckpoint the original checkpointed register state for processes
557 * in transactions.
558 */
559static long restore_tm_user_regs(struct pt_regs *regs,
560 struct mcontext __user *sr,
561 struct mcontext __user *tm_sr)
562{
563 unsigned long msr, msr_hi;
564 int i;
565
566 if (tm_suspend_disabled)
567 return 1;
568 /*
569 * restore general registers but not including MSR or SOFTE. Also
570 * take care of keeping r2 (TLS) intact if not a signal.
571 * See comment in signal_64.c:restore_tm_sigcontexts();
572 * TFHAR is restored from the checkpointed NIP; TEXASR and TFIAR
573 * were set by the signal delivery.
574 */
575 if (!user_read_access_begin(sr, sizeof(*sr)))
576 return 1;
577
578 unsafe_restore_general_regs(¤t->thread.ckpt_regs, sr, failed);
579 unsafe_get_user(current->thread.tm_tfhar, &sr->mc_gregs[PT_NIP], failed);
580 unsafe_get_user(msr, &sr->mc_gregs[PT_MSR], failed);
581
582 /* Restore the previous little-endian mode */
583 regs_set_return_msr(regs, (regs->msr & ~MSR_LE) | (msr & MSR_LE));
584
585 regs_set_return_msr(regs, regs->msr & ~MSR_VEC);
586 if (msr & MSR_VEC) {
587 /* restore altivec registers from the stack */
588 unsafe_copy_from_user(¤t->thread.ckvr_state, &sr->mc_vregs,
589 sizeof(sr->mc_vregs), failed);
590 current->thread.used_vr = true;
591 } else if (current->thread.used_vr) {
592 memset(¤t->thread.vr_state, 0,
593 ELF_NVRREG * sizeof(vector128));
594 memset(¤t->thread.ckvr_state, 0,
595 ELF_NVRREG * sizeof(vector128));
596 }
597
598 /* Always get VRSAVE back */
599 unsafe_get_user(current->thread.ckvrsave,
600 (u32 __user *)&sr->mc_vregs[32], failed);
601 if (cpu_has_feature(CPU_FTR_ALTIVEC))
602 mtspr(SPRN_VRSAVE, current->thread.ckvrsave);
603
604 regs_set_return_msr(regs, regs->msr & ~(MSR_FP | MSR_FE0 | MSR_FE1));
605
606 unsafe_copy_fpr_from_user(current, &sr->mc_fregs, failed);
607
608 regs_set_return_msr(regs, regs->msr & ~MSR_VSX);
609 if (msr & MSR_VSX) {
610 /*
611 * Restore altivec registers from the stack to a local
612 * buffer, then write this out to the thread_struct
613 */
614 unsafe_copy_ckvsx_from_user(current, &sr->mc_vsregs, failed);
615 current->thread.used_vsr = true;
616 } else if (current->thread.used_vsr)
617 for (i = 0; i < 32 ; i++) {
618 current->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
619 current->thread.ckfp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
620 }
621
622 user_read_access_end();
623
624 if (!user_read_access_begin(tm_sr, sizeof(*tm_sr)))
625 return 1;
626
627 unsafe_restore_general_regs(regs, tm_sr, failed);
628
629 /* restore altivec registers from the stack */
630 if (msr & MSR_VEC)
631 unsafe_copy_from_user(¤t->thread.vr_state, &tm_sr->mc_vregs,
632 sizeof(sr->mc_vregs), failed);
633
634 /* Always get VRSAVE back */
635 unsafe_get_user(current->thread.vrsave,
636 (u32 __user *)&tm_sr->mc_vregs[32], failed);
637
638 unsafe_copy_ckfpr_from_user(current, &tm_sr->mc_fregs, failed);
639
640 if (msr & MSR_VSX) {
641 /*
642 * Restore altivec registers from the stack to a local
643 * buffer, then write this out to the thread_struct
644 */
645 unsafe_copy_vsx_from_user(current, &tm_sr->mc_vsregs, failed);
646 current->thread.used_vsr = true;
647 }
648
649 /* Get the top half of the MSR from the user context */
650 unsafe_get_user(msr_hi, &tm_sr->mc_gregs[PT_MSR], failed);
651 msr_hi <<= 32;
652
653 user_read_access_end();
654
655 /* If TM bits are set to the reserved value, it's an invalid context */
656 if (MSR_TM_RESV(msr_hi))
657 return 1;
658
659 /*
660 * Disabling preemption, since it is unsafe to be preempted
661 * with MSR[TS] set without recheckpointing.
662 */
663 preempt_disable();
664
665 /*
666 * CAUTION:
667 * After regs->MSR[TS] being updated, make sure that get_user(),
668 * put_user() or similar functions are *not* called. These
669 * functions can generate page faults which will cause the process
670 * to be de-scheduled with MSR[TS] set but without calling
671 * tm_recheckpoint(). This can cause a bug.
672 *
673 * Pull in the MSR TM bits from the user context
674 */
675 regs_set_return_msr(regs, (regs->msr & ~MSR_TS_MASK) | (msr_hi & MSR_TS_MASK));
676 /* Now, recheckpoint. This loads up all of the checkpointed (older)
677 * registers, including FP and V[S]Rs. After recheckpointing, the
678 * transactional versions should be loaded.
679 */
680 tm_enable();
681 /* Make sure the transaction is marked as failed */
682 current->thread.tm_texasr |= TEXASR_FS;
683 /* This loads the checkpointed FP/VEC state, if used */
684 tm_recheckpoint(¤t->thread);
685
686 /* This loads the speculative FP/VEC state, if used */
687 msr_check_and_set(msr & (MSR_FP | MSR_VEC));
688 if (msr & MSR_FP) {
689 load_fp_state(¤t->thread.fp_state);
690 regs_set_return_msr(regs, regs->msr | (MSR_FP | current->thread.fpexc_mode));
691 }
692 if (msr & MSR_VEC) {
693 load_vr_state(¤t->thread.vr_state);
694 regs_set_return_msr(regs, regs->msr | MSR_VEC);
695 }
696
697 preempt_enable();
698
699 return 0;
700
701failed:
702 user_read_access_end();
703 return 1;
704}
705#else
706static long restore_tm_user_regs(struct pt_regs *regs, struct mcontext __user *sr,
707 struct mcontext __user *tm_sr)
708{
709 return 0;
710}
711#endif
712
713#ifdef CONFIG_PPC64
714
715#define copy_siginfo_to_user copy_siginfo_to_user32
716
717#endif /* CONFIG_PPC64 */
718
719/*
720 * Set up a signal frame for a "real-time" signal handler
721 * (one which gets siginfo).
722 */
723int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
724 struct task_struct *tsk)
725{
726 struct rt_sigframe __user *frame;
727 struct mcontext __user *mctx;
728 struct mcontext __user *tm_mctx = NULL;
729 unsigned long newsp = 0;
730 unsigned long tramp;
731 struct pt_regs *regs = tsk->thread.regs;
732 /* Save the thread's msr before get_tm_stackpointer() changes it */
733 unsigned long msr = regs->msr;
734
735 /* Set up Signal Frame */
736 frame = get_sigframe(ksig, tsk, sizeof(*frame), 1);
737 mctx = &frame->uc.uc_mcontext;
738#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
739 tm_mctx = &frame->uc_transact.uc_mcontext;
740#endif
741 if (MSR_TM_ACTIVE(msr))
742 prepare_save_tm_user_regs();
743 else
744 prepare_save_user_regs(1);
745
746 if (!user_access_begin(frame, sizeof(*frame)))
747 goto badframe;
748
749 /* Put the siginfo & fill in most of the ucontext */
750 unsafe_put_user(0, &frame->uc.uc_flags, failed);
751#ifdef CONFIG_PPC64
752 unsafe_compat_save_altstack(&frame->uc.uc_stack, regs->gpr[1], failed);
753#else
754 unsafe_save_altstack(&frame->uc.uc_stack, regs->gpr[1], failed);
755#endif
756 unsafe_put_user(to_user_ptr(&frame->uc.uc_mcontext), &frame->uc.uc_regs, failed);
757
758 if (MSR_TM_ACTIVE(msr)) {
759#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
760 unsafe_put_user((unsigned long)&frame->uc_transact,
761 &frame->uc.uc_link, failed);
762 unsafe_put_user((unsigned long)tm_mctx,
763 &frame->uc_transact.uc_regs, failed);
764#endif
765 unsafe_save_tm_user_regs(regs, mctx, tm_mctx, msr, failed);
766 } else {
767 unsafe_put_user(0, &frame->uc.uc_link, failed);
768 unsafe_save_user_regs(regs, mctx, tm_mctx, 1, failed);
769 }
770
771 /* Save user registers on the stack */
772 if (tsk->mm->context.vdso) {
773 tramp = VDSO32_SYMBOL(tsk->mm->context.vdso, sigtramp_rt32);
774 } else {
775 tramp = (unsigned long)mctx->mc_pad;
776 unsafe_put_user(PPC_RAW_LI(_R0, __NR_rt_sigreturn), &mctx->mc_pad[0], failed);
777 unsafe_put_user(PPC_RAW_SC(), &mctx->mc_pad[1], failed);
778 asm("dcbst %y0; sync; icbi %y0; sync" :: "Z" (mctx->mc_pad[0]));
779 }
780 unsafe_put_sigset_t(&frame->uc.uc_sigmask, oldset, failed);
781
782 user_access_end();
783
784 if (copy_siginfo_to_user(&frame->info, &ksig->info))
785 goto badframe;
786
787 regs->link = tramp;
788
789#ifdef CONFIG_PPC_FPU_REGS
790 tsk->thread.fp_state.fpscr = 0; /* turn off all fp exceptions */
791#endif
792
793 /* create a stack frame for the caller of the handler */
794 newsp = ((unsigned long)frame) - (__SIGNAL_FRAMESIZE + 16);
795 if (put_user(regs->gpr[1], (u32 __user *)newsp))
796 goto badframe;
797
798 /* Fill registers for signal handler */
799 regs->gpr[1] = newsp;
800 regs->gpr[3] = ksig->sig;
801 regs->gpr[4] = (unsigned long)&frame->info;
802 regs->gpr[5] = (unsigned long)&frame->uc;
803 regs->gpr[6] = (unsigned long)frame;
804 regs_set_return_ip(regs, (unsigned long) ksig->ka.sa.sa_handler);
805 /* enter the signal handler in native-endian mode */
806 regs_set_return_msr(regs, (regs->msr & ~MSR_LE) | (MSR_KERNEL & MSR_LE));
807
808 return 0;
809
810failed:
811 user_access_end();
812
813badframe:
814 signal_fault(tsk, regs, "handle_rt_signal32", frame);
815
816 return 1;
817}
818
819/*
820 * OK, we're invoking a handler
821 */
822int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
823 struct task_struct *tsk)
824{
825 struct sigcontext __user *sc;
826 struct sigframe __user *frame;
827 struct mcontext __user *mctx;
828 struct mcontext __user *tm_mctx = NULL;
829 unsigned long newsp = 0;
830 unsigned long tramp;
831 struct pt_regs *regs = tsk->thread.regs;
832 /* Save the thread's msr before get_tm_stackpointer() changes it */
833 unsigned long msr = regs->msr;
834
835 /* Set up Signal Frame */
836 frame = get_sigframe(ksig, tsk, sizeof(*frame), 1);
837 mctx = &frame->mctx;
838#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
839 tm_mctx = &frame->mctx_transact;
840#endif
841 if (MSR_TM_ACTIVE(msr))
842 prepare_save_tm_user_regs();
843 else
844 prepare_save_user_regs(1);
845
846 if (!user_access_begin(frame, sizeof(*frame)))
847 goto badframe;
848 sc = (struct sigcontext __user *) &frame->sctx;
849
850#if _NSIG != 64
851#error "Please adjust handle_signal()"
852#endif
853 unsafe_put_user(to_user_ptr(ksig->ka.sa.sa_handler), &sc->handler, failed);
854 unsafe_put_user(oldset->sig[0], &sc->oldmask, failed);
855#ifdef CONFIG_PPC64
856 unsafe_put_user((oldset->sig[0] >> 32), &sc->_unused[3], failed);
857#else
858 unsafe_put_user(oldset->sig[1], &sc->_unused[3], failed);
859#endif
860 unsafe_put_user(to_user_ptr(mctx), &sc->regs, failed);
861 unsafe_put_user(ksig->sig, &sc->signal, failed);
862
863 if (MSR_TM_ACTIVE(msr))
864 unsafe_save_tm_user_regs(regs, mctx, tm_mctx, msr, failed);
865 else
866 unsafe_save_user_regs(regs, mctx, tm_mctx, 1, failed);
867
868 if (tsk->mm->context.vdso) {
869 tramp = VDSO32_SYMBOL(tsk->mm->context.vdso, sigtramp32);
870 } else {
871 tramp = (unsigned long)mctx->mc_pad;
872 unsafe_put_user(PPC_RAW_LI(_R0, __NR_sigreturn), &mctx->mc_pad[0], failed);
873 unsafe_put_user(PPC_RAW_SC(), &mctx->mc_pad[1], failed);
874 asm("dcbst %y0; sync; icbi %y0; sync" :: "Z" (mctx->mc_pad[0]));
875 }
876 user_access_end();
877
878 regs->link = tramp;
879
880#ifdef CONFIG_PPC_FPU_REGS
881 tsk->thread.fp_state.fpscr = 0; /* turn off all fp exceptions */
882#endif
883
884 /* create a stack frame for the caller of the handler */
885 newsp = ((unsigned long)frame) - __SIGNAL_FRAMESIZE;
886 if (put_user(regs->gpr[1], (u32 __user *)newsp))
887 goto badframe;
888
889 regs->gpr[1] = newsp;
890 regs->gpr[3] = ksig->sig;
891 regs->gpr[4] = (unsigned long) sc;
892 regs_set_return_ip(regs, (unsigned long) ksig->ka.sa.sa_handler);
893 /* enter the signal handler in native-endian mode */
894 regs_set_return_msr(regs, (regs->msr & ~MSR_LE) | (MSR_KERNEL & MSR_LE));
895
896 return 0;
897
898failed:
899 user_access_end();
900
901badframe:
902 signal_fault(tsk, regs, "handle_signal32", frame);
903
904 return 1;
905}
906
907static int do_setcontext(struct ucontext __user *ucp, struct pt_regs *regs, int sig)
908{
909 sigset_t set;
910 struct mcontext __user *mcp;
911
912 if (!user_read_access_begin(ucp, sizeof(*ucp)))
913 return -EFAULT;
914
915 unsafe_get_sigset_t(&set, &ucp->uc_sigmask, failed);
916#ifdef CONFIG_PPC64
917 {
918 u32 cmcp;
919
920 unsafe_get_user(cmcp, &ucp->uc_regs, failed);
921 mcp = (struct mcontext __user *)(u64)cmcp;
922 }
923#else
924 unsafe_get_user(mcp, &ucp->uc_regs, failed);
925#endif
926 user_read_access_end();
927
928 set_current_blocked(&set);
929 if (restore_user_regs(regs, mcp, sig))
930 return -EFAULT;
931
932 return 0;
933
934failed:
935 user_read_access_end();
936 return -EFAULT;
937}
938
939#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
940static int do_setcontext_tm(struct ucontext __user *ucp,
941 struct ucontext __user *tm_ucp,
942 struct pt_regs *regs)
943{
944 sigset_t set;
945 struct mcontext __user *mcp;
946 struct mcontext __user *tm_mcp;
947 u32 cmcp;
948 u32 tm_cmcp;
949
950 if (!user_read_access_begin(ucp, sizeof(*ucp)))
951 return -EFAULT;
952
953 unsafe_get_sigset_t(&set, &ucp->uc_sigmask, failed);
954 unsafe_get_user(cmcp, &ucp->uc_regs, failed);
955
956 user_read_access_end();
957
958 if (__get_user(tm_cmcp, &tm_ucp->uc_regs))
959 return -EFAULT;
960 mcp = (struct mcontext __user *)(u64)cmcp;
961 tm_mcp = (struct mcontext __user *)(u64)tm_cmcp;
962 /* no need to check access_ok(mcp), since mcp < 4GB */
963
964 set_current_blocked(&set);
965 if (restore_tm_user_regs(regs, mcp, tm_mcp))
966 return -EFAULT;
967
968 return 0;
969
970failed:
971 user_read_access_end();
972 return -EFAULT;
973}
974#endif
975
976#ifdef CONFIG_PPC64
977COMPAT_SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx,
978 struct ucontext __user *, new_ctx, int, ctx_size)
979#else
980SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx,
981 struct ucontext __user *, new_ctx, long, ctx_size)
982#endif
983{
984 struct pt_regs *regs = current_pt_regs();
985 int ctx_has_vsx_region = 0;
986
987#ifdef CONFIG_PPC64
988 unsigned long new_msr = 0;
989
990 if (new_ctx) {
991 struct mcontext __user *mcp;
992 u32 cmcp;
993
994 /*
995 * Get pointer to the real mcontext. No need for
996 * access_ok since we are dealing with compat
997 * pointers.
998 */
999 if (__get_user(cmcp, &new_ctx->uc_regs))
1000 return -EFAULT;
1001 mcp = (struct mcontext __user *)(u64)cmcp;
1002 if (__get_user(new_msr, &mcp->mc_gregs[PT_MSR]))
1003 return -EFAULT;
1004 }
1005 /*
1006 * Check that the context is not smaller than the original
1007 * size (with VMX but without VSX)
1008 */
1009 if (ctx_size < UCONTEXTSIZEWITHOUTVSX)
1010 return -EINVAL;
1011 /*
1012 * If the new context state sets the MSR VSX bits but
1013 * it doesn't provide VSX state.
1014 */
1015 if ((ctx_size < sizeof(struct ucontext)) &&
1016 (new_msr & MSR_VSX))
1017 return -EINVAL;
1018 /* Does the context have enough room to store VSX data? */
1019 if (ctx_size >= sizeof(struct ucontext))
1020 ctx_has_vsx_region = 1;
1021#else
1022 /* Context size is for future use. Right now, we only make sure
1023 * we are passed something we understand
1024 */
1025 if (ctx_size < sizeof(struct ucontext))
1026 return -EINVAL;
1027#endif
1028 if (old_ctx != NULL) {
1029 struct mcontext __user *mctx;
1030
1031 /*
1032 * old_ctx might not be 16-byte aligned, in which
1033 * case old_ctx->uc_mcontext won't be either.
1034 * Because we have the old_ctx->uc_pad2 field
1035 * before old_ctx->uc_mcontext, we need to round down
1036 * from &old_ctx->uc_mcontext to a 16-byte boundary.
1037 */
1038 mctx = (struct mcontext __user *)
1039 ((unsigned long) &old_ctx->uc_mcontext & ~0xfUL);
1040 prepare_save_user_regs(ctx_has_vsx_region);
1041 if (!user_write_access_begin(old_ctx, ctx_size))
1042 return -EFAULT;
1043 unsafe_save_user_regs(regs, mctx, NULL, ctx_has_vsx_region, failed);
1044 unsafe_put_sigset_t(&old_ctx->uc_sigmask, ¤t->blocked, failed);
1045 unsafe_put_user(to_user_ptr(mctx), &old_ctx->uc_regs, failed);
1046 user_write_access_end();
1047 }
1048 if (new_ctx == NULL)
1049 return 0;
1050 if (!access_ok(new_ctx, ctx_size) ||
1051 fault_in_pages_readable((u8 __user *)new_ctx, ctx_size))
1052 return -EFAULT;
1053
1054 /*
1055 * If we get a fault copying the context into the kernel's
1056 * image of the user's registers, we can't just return -EFAULT
1057 * because the user's registers will be corrupted. For instance
1058 * the NIP value may have been updated but not some of the
1059 * other registers. Given that we have done the access_ok
1060 * and successfully read the first and last bytes of the region
1061 * above, this should only happen in an out-of-memory situation
1062 * or if another thread unmaps the region containing the context.
1063 * We kill the task with a SIGSEGV in this situation.
1064 */
1065 if (do_setcontext(new_ctx, regs, 0))
1066 do_exit(SIGSEGV);
1067
1068 set_thread_flag(TIF_RESTOREALL);
1069 return 0;
1070
1071failed:
1072 user_write_access_end();
1073 return -EFAULT;
1074}
1075
1076#ifdef CONFIG_PPC64
1077COMPAT_SYSCALL_DEFINE0(rt_sigreturn)
1078#else
1079SYSCALL_DEFINE0(rt_sigreturn)
1080#endif
1081{
1082 struct rt_sigframe __user *rt_sf;
1083 struct pt_regs *regs = current_pt_regs();
1084 int tm_restore = 0;
1085#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1086 struct ucontext __user *uc_transact;
1087 unsigned long msr_hi;
1088 unsigned long tmp;
1089#endif
1090 /* Always make any pending restarted system calls return -EINTR */
1091 current->restart_block.fn = do_no_restart_syscall;
1092
1093 rt_sf = (struct rt_sigframe __user *)
1094 (regs->gpr[1] + __SIGNAL_FRAMESIZE + 16);
1095 if (!access_ok(rt_sf, sizeof(*rt_sf)))
1096 goto bad;
1097
1098#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1099 /*
1100 * If there is a transactional state then throw it away.
1101 * The purpose of a sigreturn is to destroy all traces of the
1102 * signal frame, this includes any transactional state created
1103 * within in. We only check for suspended as we can never be
1104 * active in the kernel, we are active, there is nothing better to
1105 * do than go ahead and Bad Thing later.
1106 * The cause is not important as there will never be a
1107 * recheckpoint so it's not user visible.
1108 */
1109 if (MSR_TM_SUSPENDED(mfmsr()))
1110 tm_reclaim_current(0);
1111
1112 if (__get_user(tmp, &rt_sf->uc.uc_link))
1113 goto bad;
1114 uc_transact = (struct ucontext __user *)(uintptr_t)tmp;
1115 if (uc_transact) {
1116 u32 cmcp;
1117 struct mcontext __user *mcp;
1118
1119 if (__get_user(cmcp, &uc_transact->uc_regs))
1120 return -EFAULT;
1121 mcp = (struct mcontext __user *)(u64)cmcp;
1122 /* The top 32 bits of the MSR are stashed in the transactional
1123 * ucontext. */
1124 if (__get_user(msr_hi, &mcp->mc_gregs[PT_MSR]))
1125 goto bad;
1126
1127 if (MSR_TM_ACTIVE(msr_hi<<32)) {
1128 /* Trying to start TM on non TM system */
1129 if (!cpu_has_feature(CPU_FTR_TM))
1130 goto bad;
1131 /* We only recheckpoint on return if we're
1132 * transaction.
1133 */
1134 tm_restore = 1;
1135 if (do_setcontext_tm(&rt_sf->uc, uc_transact, regs))
1136 goto bad;
1137 }
1138 }
1139 if (!tm_restore) {
1140 /*
1141 * Unset regs->msr because ucontext MSR TS is not
1142 * set, and recheckpoint was not called. This avoid
1143 * hitting a TM Bad thing at RFID
1144 */
1145 regs_set_return_msr(regs, regs->msr & ~MSR_TS_MASK);
1146 }
1147 /* Fall through, for non-TM restore */
1148#endif
1149 if (!tm_restore)
1150 if (do_setcontext(&rt_sf->uc, regs, 1))
1151 goto bad;
1152
1153 /*
1154 * It's not clear whether or why it is desirable to save the
1155 * sigaltstack setting on signal delivery and restore it on
1156 * signal return. But other architectures do this and we have
1157 * always done it up until now so it is probably better not to
1158 * change it. -- paulus
1159 */
1160#ifdef CONFIG_PPC64
1161 if (compat_restore_altstack(&rt_sf->uc.uc_stack))
1162 goto bad;
1163#else
1164 if (restore_altstack(&rt_sf->uc.uc_stack))
1165 goto bad;
1166#endif
1167 set_thread_flag(TIF_RESTOREALL);
1168 return 0;
1169
1170 bad:
1171 signal_fault(current, regs, "sys_rt_sigreturn", rt_sf);
1172
1173 force_sig(SIGSEGV);
1174 return 0;
1175}
1176
1177#ifdef CONFIG_PPC32
1178SYSCALL_DEFINE3(debug_setcontext, struct ucontext __user *, ctx,
1179 int, ndbg, struct sig_dbg_op __user *, dbg)
1180{
1181 struct pt_regs *regs = current_pt_regs();
1182 struct sig_dbg_op op;
1183 int i;
1184 unsigned long new_msr = regs->msr;
1185#ifdef CONFIG_PPC_ADV_DEBUG_REGS
1186 unsigned long new_dbcr0 = current->thread.debug.dbcr0;
1187#endif
1188
1189 for (i=0; i<ndbg; i++) {
1190 if (copy_from_user(&op, dbg + i, sizeof(op)))
1191 return -EFAULT;
1192 switch (op.dbg_type) {
1193 case SIG_DBG_SINGLE_STEPPING:
1194#ifdef CONFIG_PPC_ADV_DEBUG_REGS
1195 if (op.dbg_value) {
1196 new_msr |= MSR_DE;
1197 new_dbcr0 |= (DBCR0_IDM | DBCR0_IC);
1198 } else {
1199 new_dbcr0 &= ~DBCR0_IC;
1200 if (!DBCR_ACTIVE_EVENTS(new_dbcr0,
1201 current->thread.debug.dbcr1)) {
1202 new_msr &= ~MSR_DE;
1203 new_dbcr0 &= ~DBCR0_IDM;
1204 }
1205 }
1206#else
1207 if (op.dbg_value)
1208 new_msr |= MSR_SE;
1209 else
1210 new_msr &= ~MSR_SE;
1211#endif
1212 break;
1213 case SIG_DBG_BRANCH_TRACING:
1214#ifdef CONFIG_PPC_ADV_DEBUG_REGS
1215 return -EINVAL;
1216#else
1217 if (op.dbg_value)
1218 new_msr |= MSR_BE;
1219 else
1220 new_msr &= ~MSR_BE;
1221#endif
1222 break;
1223
1224 default:
1225 return -EINVAL;
1226 }
1227 }
1228
1229 /* We wait until here to actually install the values in the
1230 registers so if we fail in the above loop, it will not
1231 affect the contents of these registers. After this point,
1232 failure is a problem, anyway, and it's very unlikely unless
1233 the user is really doing something wrong. */
1234 regs_set_return_msr(regs, new_msr);
1235#ifdef CONFIG_PPC_ADV_DEBUG_REGS
1236 current->thread.debug.dbcr0 = new_dbcr0;
1237#endif
1238
1239 if (!access_ok(ctx, sizeof(*ctx)) ||
1240 fault_in_pages_readable((u8 __user *)ctx, sizeof(*ctx)))
1241 return -EFAULT;
1242
1243 /*
1244 * If we get a fault copying the context into the kernel's
1245 * image of the user's registers, we can't just return -EFAULT
1246 * because the user's registers will be corrupted. For instance
1247 * the NIP value may have been updated but not some of the
1248 * other registers. Given that we have done the access_ok
1249 * and successfully read the first and last bytes of the region
1250 * above, this should only happen in an out-of-memory situation
1251 * or if another thread unmaps the region containing the context.
1252 * We kill the task with a SIGSEGV in this situation.
1253 */
1254 if (do_setcontext(ctx, regs, 1)) {
1255 signal_fault(current, regs, "sys_debug_setcontext", ctx);
1256
1257 force_sig(SIGSEGV);
1258 goto out;
1259 }
1260
1261 /*
1262 * It's not clear whether or why it is desirable to save the
1263 * sigaltstack setting on signal delivery and restore it on
1264 * signal return. But other architectures do this and we have
1265 * always done it up until now so it is probably better not to
1266 * change it. -- paulus
1267 */
1268 restore_altstack(&ctx->uc_stack);
1269
1270 set_thread_flag(TIF_RESTOREALL);
1271 out:
1272 return 0;
1273}
1274#endif
1275
1276/*
1277 * Do a signal return; undo the signal stack.
1278 */
1279#ifdef CONFIG_PPC64
1280COMPAT_SYSCALL_DEFINE0(sigreturn)
1281#else
1282SYSCALL_DEFINE0(sigreturn)
1283#endif
1284{
1285 struct pt_regs *regs = current_pt_regs();
1286 struct sigframe __user *sf;
1287 struct sigcontext __user *sc;
1288 struct sigcontext sigctx;
1289 struct mcontext __user *sr;
1290 sigset_t set;
1291 struct mcontext __user *mcp;
1292 struct mcontext __user *tm_mcp = NULL;
1293 unsigned long long msr_hi = 0;
1294
1295 /* Always make any pending restarted system calls return -EINTR */
1296 current->restart_block.fn = do_no_restart_syscall;
1297
1298 sf = (struct sigframe __user *)(regs->gpr[1] + __SIGNAL_FRAMESIZE);
1299 sc = &sf->sctx;
1300 if (copy_from_user(&sigctx, sc, sizeof(sigctx)))
1301 goto badframe;
1302
1303#ifdef CONFIG_PPC64
1304 /*
1305 * Note that PPC32 puts the upper 32 bits of the sigmask in the
1306 * unused part of the signal stackframe
1307 */
1308 set.sig[0] = sigctx.oldmask + ((long)(sigctx._unused[3]) << 32);
1309#else
1310 set.sig[0] = sigctx.oldmask;
1311 set.sig[1] = sigctx._unused[3];
1312#endif
1313 set_current_blocked(&set);
1314
1315 mcp = (struct mcontext __user *)&sf->mctx;
1316#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1317 tm_mcp = (struct mcontext __user *)&sf->mctx_transact;
1318 if (__get_user(msr_hi, &tm_mcp->mc_gregs[PT_MSR]))
1319 goto badframe;
1320#endif
1321 if (MSR_TM_ACTIVE(msr_hi<<32)) {
1322 if (!cpu_has_feature(CPU_FTR_TM))
1323 goto badframe;
1324 if (restore_tm_user_regs(regs, mcp, tm_mcp))
1325 goto badframe;
1326 } else {
1327 sr = (struct mcontext __user *)from_user_ptr(sigctx.regs);
1328 if (restore_user_regs(regs, sr, 1)) {
1329 signal_fault(current, regs, "sys_sigreturn", sr);
1330
1331 force_sig(SIGSEGV);
1332 return 0;
1333 }
1334 }
1335
1336 set_thread_flag(TIF_RESTOREALL);
1337 return 0;
1338
1339badframe:
1340 signal_fault(current, regs, "sys_sigreturn", sc);
1341
1342 force_sig(SIGSEGV);
1343 return 0;
1344}