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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#define __save_altstack __compat_save_altstack
62
63/*
64 * Userspace code may pass a ucontext which doesn't include VSX added
65 * at the end. We need to check for this case.
66 */
67#define UCONTEXTSIZEWITHOUTVSX \
68 (sizeof(struct ucontext) - sizeof(elf_vsrreghalf_t32))
69
70/*
71 * Returning 0 means we return to userspace via
72 * ret_from_except and thus restore all user
73 * registers from *regs. This is what we need
74 * to do when a signal has been delivered.
75 */
76
77#define GP_REGS_SIZE min(sizeof(elf_gregset_t32), sizeof(struct pt_regs32))
78#undef __SIGNAL_FRAMESIZE
79#define __SIGNAL_FRAMESIZE __SIGNAL_FRAMESIZE32
80#undef ELF_NVRREG
81#define ELF_NVRREG ELF_NVRREG32
82
83/*
84 * Functions for flipping sigsets (thanks to brain dead generic
85 * implementation that makes things simple for little endian only)
86 */
87static inline int put_sigset_t(compat_sigset_t __user *uset, sigset_t *set)
88{
89 return put_compat_sigset(uset, set, sizeof(*uset));
90}
91
92static inline int get_sigset_t(sigset_t *set,
93 const compat_sigset_t __user *uset)
94{
95 return get_compat_sigset(set, uset);
96}
97
98#define to_user_ptr(p) ptr_to_compat(p)
99#define from_user_ptr(p) compat_ptr(p)
100
101static inline int save_general_regs(struct pt_regs *regs,
102 struct mcontext __user *frame)
103{
104 elf_greg_t64 *gregs = (elf_greg_t64 *)regs;
105 int val, i;
106
107 WARN_ON(!FULL_REGS(regs));
108
109 for (i = 0; i <= PT_RESULT; i ++) {
110 /* Force usr to alway see softe as 1 (interrupts enabled) */
111 if (i == PT_SOFTE)
112 val = 1;
113 else
114 val = gregs[i];
115
116 if (__put_user(val, &frame->mc_gregs[i]))
117 return -EFAULT;
118 }
119 return 0;
120}
121
122static inline int restore_general_regs(struct pt_regs *regs,
123 struct mcontext __user *sr)
124{
125 elf_greg_t64 *gregs = (elf_greg_t64 *)regs;
126 int i;
127
128 for (i = 0; i <= PT_RESULT; i++) {
129 if ((i == PT_MSR) || (i == PT_SOFTE))
130 continue;
131 if (__get_user(gregs[i], &sr->mc_gregs[i]))
132 return -EFAULT;
133 }
134 return 0;
135}
136
137#else /* CONFIG_PPC64 */
138
139#define GP_REGS_SIZE min(sizeof(elf_gregset_t), sizeof(struct pt_regs))
140
141static inline int put_sigset_t(sigset_t __user *uset, sigset_t *set)
142{
143 return copy_to_user(uset, set, sizeof(*uset));
144}
145
146static inline int get_sigset_t(sigset_t *set, const sigset_t __user *uset)
147{
148 return copy_from_user(set, uset, sizeof(*uset));
149}
150
151#define to_user_ptr(p) ((unsigned long)(p))
152#define from_user_ptr(p) ((void __user *)(p))
153
154static inline int save_general_regs(struct pt_regs *regs,
155 struct mcontext __user *frame)
156{
157 WARN_ON(!FULL_REGS(regs));
158 return __copy_to_user(&frame->mc_gregs, regs, GP_REGS_SIZE);
159}
160
161static inline int restore_general_regs(struct pt_regs *regs,
162 struct mcontext __user *sr)
163{
164 /* copy up to but not including MSR */
165 if (__copy_from_user(regs, &sr->mc_gregs,
166 PT_MSR * sizeof(elf_greg_t)))
167 return -EFAULT;
168 /* copy from orig_r3 (the word after the MSR) up to the end */
169 if (__copy_from_user(®s->orig_gpr3, &sr->mc_gregs[PT_ORIG_R3],
170 GP_REGS_SIZE - PT_ORIG_R3 * sizeof(elf_greg_t)))
171 return -EFAULT;
172 return 0;
173}
174#endif
175
176/*
177 * When we have signals to deliver, we set up on the
178 * user stack, going down from the original stack pointer:
179 * an ABI gap of 56 words
180 * an mcontext struct
181 * a sigcontext struct
182 * a gap of __SIGNAL_FRAMESIZE bytes
183 *
184 * Each of these things must be a multiple of 16 bytes in size. The following
185 * structure represent all of this except the __SIGNAL_FRAMESIZE gap
186 *
187 */
188struct sigframe {
189 struct sigcontext sctx; /* the sigcontext */
190 struct mcontext mctx; /* all the register values */
191#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
192 struct sigcontext sctx_transact;
193 struct mcontext mctx_transact;
194#endif
195 /*
196 * Programs using the rs6000/xcoff abi can save up to 19 gp
197 * regs and 18 fp regs below sp before decrementing it.
198 */
199 int abigap[56];
200};
201
202/* We use the mc_pad field for the signal return trampoline. */
203#define tramp mc_pad
204
205/*
206 * When we have rt signals to deliver, we set up on the
207 * user stack, going down from the original stack pointer:
208 * one rt_sigframe struct (siginfo + ucontext + ABI gap)
209 * a gap of __SIGNAL_FRAMESIZE+16 bytes
210 * (the +16 is to get the siginfo and ucontext in the same
211 * positions as in older kernels).
212 *
213 * Each of these things must be a multiple of 16 bytes in size.
214 *
215 */
216struct rt_sigframe {
217#ifdef CONFIG_PPC64
218 compat_siginfo_t info;
219#else
220 struct siginfo info;
221#endif
222 struct ucontext uc;
223#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
224 struct ucontext uc_transact;
225#endif
226 /*
227 * Programs using the rs6000/xcoff abi can save up to 19 gp
228 * regs and 18 fp regs below sp before decrementing it.
229 */
230 int abigap[56];
231};
232
233/*
234 * Save the current user registers on the user stack.
235 * We only save the altivec/spe registers if the process has used
236 * altivec/spe instructions at some point.
237 */
238static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
239 struct mcontext __user *tm_frame, int sigret,
240 int ctx_has_vsx_region)
241{
242 unsigned long msr = regs->msr;
243
244 /* Make sure floating point registers are stored in regs */
245 flush_fp_to_thread(current);
246
247 /* save general registers */
248 if (save_general_regs(regs, frame))
249 return 1;
250
251#ifdef CONFIG_ALTIVEC
252 /* save altivec registers */
253 if (current->thread.used_vr) {
254 flush_altivec_to_thread(current);
255 if (__copy_to_user(&frame->mc_vregs, ¤t->thread.vr_state,
256 ELF_NVRREG * sizeof(vector128)))
257 return 1;
258 /* set MSR_VEC in the saved MSR value to indicate that
259 frame->mc_vregs contains valid data */
260 msr |= MSR_VEC;
261 }
262 /* else assert((regs->msr & MSR_VEC) == 0) */
263
264 /* We always copy to/from vrsave, it's 0 if we don't have or don't
265 * use altivec. Since VSCR only contains 32 bits saved in the least
266 * significant bits of a vector, we "cheat" and stuff VRSAVE in the
267 * most significant bits of that same vector. --BenH
268 * Note that the current VRSAVE value is in the SPR at this point.
269 */
270 if (cpu_has_feature(CPU_FTR_ALTIVEC))
271 current->thread.vrsave = mfspr(SPRN_VRSAVE);
272 if (__put_user(current->thread.vrsave, (u32 __user *)&frame->mc_vregs[32]))
273 return 1;
274#endif /* CONFIG_ALTIVEC */
275 if (copy_fpr_to_user(&frame->mc_fregs, current))
276 return 1;
277
278 /*
279 * Clear the MSR VSX bit to indicate there is no valid state attached
280 * to this context, except in the specific case below where we set it.
281 */
282 msr &= ~MSR_VSX;
283#ifdef CONFIG_VSX
284 /*
285 * Copy VSR 0-31 upper half from thread_struct to local
286 * buffer, then write that to userspace. Also set MSR_VSX in
287 * the saved MSR value to indicate that frame->mc_vregs
288 * contains valid data
289 */
290 if (current->thread.used_vsr && ctx_has_vsx_region) {
291 flush_vsx_to_thread(current);
292 if (copy_vsx_to_user(&frame->mc_vsregs, current))
293 return 1;
294 msr |= MSR_VSX;
295 }
296#endif /* CONFIG_VSX */
297#ifdef CONFIG_SPE
298 /* save spe registers */
299 if (current->thread.used_spe) {
300 flush_spe_to_thread(current);
301 if (__copy_to_user(&frame->mc_vregs, current->thread.evr,
302 ELF_NEVRREG * sizeof(u32)))
303 return 1;
304 /* set MSR_SPE in the saved MSR value to indicate that
305 frame->mc_vregs contains valid data */
306 msr |= MSR_SPE;
307 }
308 /* else assert((regs->msr & MSR_SPE) == 0) */
309
310 /* We always copy to/from spefscr */
311 if (__put_user(current->thread.spefscr, (u32 __user *)&frame->mc_vregs + ELF_NEVRREG))
312 return 1;
313#endif /* CONFIG_SPE */
314
315 if (__put_user(msr, &frame->mc_gregs[PT_MSR]))
316 return 1;
317 /* We need to write 0 the MSR top 32 bits in the tm frame so that we
318 * can check it on the restore to see if TM is active
319 */
320 if (tm_frame && __put_user(0, &tm_frame->mc_gregs[PT_MSR]))
321 return 1;
322
323 if (sigret) {
324 /* Set up the sigreturn trampoline: li 0,sigret; sc */
325 if (__put_user(PPC_INST_ADDI + sigret, &frame->tramp[0])
326 || __put_user(PPC_INST_SC, &frame->tramp[1]))
327 return 1;
328 flush_icache_range((unsigned long) &frame->tramp[0],
329 (unsigned long) &frame->tramp[2]);
330 }
331
332 return 0;
333}
334
335#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
336/*
337 * Save the current user registers on the user stack.
338 * We only save the altivec/spe registers if the process has used
339 * altivec/spe instructions at some point.
340 * We also save the transactional registers to a second ucontext in the
341 * frame.
342 *
343 * See save_user_regs() and signal_64.c:setup_tm_sigcontexts().
344 */
345static int save_tm_user_regs(struct pt_regs *regs,
346 struct mcontext __user *frame,
347 struct mcontext __user *tm_frame, int sigret,
348 unsigned long msr)
349{
350 WARN_ON(tm_suspend_disabled);
351
352 /* Save both sets of general registers */
353 if (save_general_regs(¤t->thread.ckpt_regs, frame)
354 || save_general_regs(regs, tm_frame))
355 return 1;
356
357 /* Stash the top half of the 64bit MSR into the 32bit MSR word
358 * of the transactional mcontext. This way we have a backward-compatible
359 * MSR in the 'normal' (checkpointed) mcontext and additionally one can
360 * also look at what type of transaction (T or S) was active at the
361 * time of the signal.
362 */
363 if (__put_user((msr >> 32), &tm_frame->mc_gregs[PT_MSR]))
364 return 1;
365
366#ifdef CONFIG_ALTIVEC
367 /* save altivec registers */
368 if (current->thread.used_vr) {
369 if (__copy_to_user(&frame->mc_vregs, ¤t->thread.ckvr_state,
370 ELF_NVRREG * sizeof(vector128)))
371 return 1;
372 if (msr & MSR_VEC) {
373 if (__copy_to_user(&tm_frame->mc_vregs,
374 ¤t->thread.vr_state,
375 ELF_NVRREG * sizeof(vector128)))
376 return 1;
377 } else {
378 if (__copy_to_user(&tm_frame->mc_vregs,
379 ¤t->thread.ckvr_state,
380 ELF_NVRREG * sizeof(vector128)))
381 return 1;
382 }
383
384 /* set MSR_VEC in the saved MSR value to indicate that
385 * frame->mc_vregs contains valid data
386 */
387 msr |= MSR_VEC;
388 }
389
390 /* We always copy to/from vrsave, it's 0 if we don't have or don't
391 * use altivec. Since VSCR only contains 32 bits saved in the least
392 * significant bits of a vector, we "cheat" and stuff VRSAVE in the
393 * most significant bits of that same vector. --BenH
394 */
395 if (cpu_has_feature(CPU_FTR_ALTIVEC))
396 current->thread.ckvrsave = mfspr(SPRN_VRSAVE);
397 if (__put_user(current->thread.ckvrsave,
398 (u32 __user *)&frame->mc_vregs[32]))
399 return 1;
400 if (msr & MSR_VEC) {
401 if (__put_user(current->thread.vrsave,
402 (u32 __user *)&tm_frame->mc_vregs[32]))
403 return 1;
404 } else {
405 if (__put_user(current->thread.ckvrsave,
406 (u32 __user *)&tm_frame->mc_vregs[32]))
407 return 1;
408 }
409#endif /* CONFIG_ALTIVEC */
410
411 if (copy_ckfpr_to_user(&frame->mc_fregs, current))
412 return 1;
413 if (msr & MSR_FP) {
414 if (copy_fpr_to_user(&tm_frame->mc_fregs, current))
415 return 1;
416 } else {
417 if (copy_ckfpr_to_user(&tm_frame->mc_fregs, current))
418 return 1;
419 }
420
421#ifdef CONFIG_VSX
422 /*
423 * Copy VSR 0-31 upper half from thread_struct to local
424 * buffer, then write that to userspace. Also set MSR_VSX in
425 * the saved MSR value to indicate that frame->mc_vregs
426 * contains valid data
427 */
428 if (current->thread.used_vsr) {
429 if (copy_ckvsx_to_user(&frame->mc_vsregs, current))
430 return 1;
431 if (msr & MSR_VSX) {
432 if (copy_vsx_to_user(&tm_frame->mc_vsregs,
433 current))
434 return 1;
435 } else {
436 if (copy_ckvsx_to_user(&tm_frame->mc_vsregs, current))
437 return 1;
438 }
439
440 msr |= MSR_VSX;
441 }
442#endif /* CONFIG_VSX */
443#ifdef CONFIG_SPE
444 /* SPE regs are not checkpointed with TM, so this section is
445 * simply the same as in save_user_regs().
446 */
447 if (current->thread.used_spe) {
448 flush_spe_to_thread(current);
449 if (__copy_to_user(&frame->mc_vregs, current->thread.evr,
450 ELF_NEVRREG * sizeof(u32)))
451 return 1;
452 /* set MSR_SPE in the saved MSR value to indicate that
453 * frame->mc_vregs contains valid data */
454 msr |= MSR_SPE;
455 }
456
457 /* We always copy to/from spefscr */
458 if (__put_user(current->thread.spefscr, (u32 __user *)&frame->mc_vregs + ELF_NEVRREG))
459 return 1;
460#endif /* CONFIG_SPE */
461
462 if (__put_user(msr, &frame->mc_gregs[PT_MSR]))
463 return 1;
464 if (sigret) {
465 /* Set up the sigreturn trampoline: li 0,sigret; sc */
466 if (__put_user(PPC_INST_ADDI + sigret, &frame->tramp[0])
467 || __put_user(PPC_INST_SC, &frame->tramp[1]))
468 return 1;
469 flush_icache_range((unsigned long) &frame->tramp[0],
470 (unsigned long) &frame->tramp[2]);
471 }
472
473 return 0;
474}
475#endif
476
477/*
478 * Restore the current user register values from the user stack,
479 * (except for MSR).
480 */
481static long restore_user_regs(struct pt_regs *regs,
482 struct mcontext __user *sr, int sig)
483{
484 long err;
485 unsigned int save_r2 = 0;
486 unsigned long msr;
487#ifdef CONFIG_VSX
488 int i;
489#endif
490
491 /*
492 * restore general registers but not including MSR or SOFTE. Also
493 * take care of keeping r2 (TLS) intact if not a signal
494 */
495 if (!sig)
496 save_r2 = (unsigned int)regs->gpr[2];
497 err = restore_general_regs(regs, sr);
498 set_trap_norestart(regs);
499 err |= __get_user(msr, &sr->mc_gregs[PT_MSR]);
500 if (!sig)
501 regs->gpr[2] = (unsigned long) save_r2;
502 if (err)
503 return 1;
504
505 /* if doing signal return, restore the previous little-endian mode */
506 if (sig)
507 regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE);
508
509#ifdef CONFIG_ALTIVEC
510 /*
511 * Force the process to reload the altivec registers from
512 * current->thread when it next does altivec instructions
513 */
514 regs->msr &= ~MSR_VEC;
515 if (msr & MSR_VEC) {
516 /* restore altivec registers from the stack */
517 if (__copy_from_user(¤t->thread.vr_state, &sr->mc_vregs,
518 sizeof(sr->mc_vregs)))
519 return 1;
520 current->thread.used_vr = true;
521 } else if (current->thread.used_vr)
522 memset(¤t->thread.vr_state, 0,
523 ELF_NVRREG * sizeof(vector128));
524
525 /* Always get VRSAVE back */
526 if (__get_user(current->thread.vrsave, (u32 __user *)&sr->mc_vregs[32]))
527 return 1;
528 if (cpu_has_feature(CPU_FTR_ALTIVEC))
529 mtspr(SPRN_VRSAVE, current->thread.vrsave);
530#endif /* CONFIG_ALTIVEC */
531 if (copy_fpr_from_user(current, &sr->mc_fregs))
532 return 1;
533
534#ifdef CONFIG_VSX
535 /*
536 * Force the process to reload the VSX registers from
537 * current->thread when it next does VSX instruction.
538 */
539 regs->msr &= ~MSR_VSX;
540 if (msr & MSR_VSX) {
541 /*
542 * Restore altivec registers from the stack to a local
543 * buffer, then write this out to the thread_struct
544 */
545 if (copy_vsx_from_user(current, &sr->mc_vsregs))
546 return 1;
547 current->thread.used_vsr = true;
548 } else if (current->thread.used_vsr)
549 for (i = 0; i < 32 ; i++)
550 current->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
551#endif /* CONFIG_VSX */
552 /*
553 * force the process to reload the FP registers from
554 * current->thread when it next does FP instructions
555 */
556 regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1);
557
558#ifdef CONFIG_SPE
559 /* force the process to reload the spe registers from
560 current->thread when it next does spe instructions */
561 regs->msr &= ~MSR_SPE;
562 if (msr & MSR_SPE) {
563 /* restore spe registers from the stack */
564 if (__copy_from_user(current->thread.evr, &sr->mc_vregs,
565 ELF_NEVRREG * sizeof(u32)))
566 return 1;
567 current->thread.used_spe = true;
568 } else if (current->thread.used_spe)
569 memset(current->thread.evr, 0, ELF_NEVRREG * sizeof(u32));
570
571 /* Always get SPEFSCR back */
572 if (__get_user(current->thread.spefscr, (u32 __user *)&sr->mc_vregs + ELF_NEVRREG))
573 return 1;
574#endif /* CONFIG_SPE */
575
576 return 0;
577}
578
579#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
580/*
581 * Restore the current user register values from the user stack, except for
582 * MSR, and recheckpoint the original checkpointed register state for processes
583 * in transactions.
584 */
585static long restore_tm_user_regs(struct pt_regs *regs,
586 struct mcontext __user *sr,
587 struct mcontext __user *tm_sr)
588{
589 long err;
590 unsigned long msr, msr_hi;
591#ifdef CONFIG_VSX
592 int i;
593#endif
594
595 if (tm_suspend_disabled)
596 return 1;
597 /*
598 * restore general registers but not including MSR or SOFTE. Also
599 * take care of keeping r2 (TLS) intact if not a signal.
600 * See comment in signal_64.c:restore_tm_sigcontexts();
601 * TFHAR is restored from the checkpointed NIP; TEXASR and TFIAR
602 * were set by the signal delivery.
603 */
604 err = restore_general_regs(regs, tm_sr);
605 err |= restore_general_regs(¤t->thread.ckpt_regs, sr);
606
607 err |= __get_user(current->thread.tm_tfhar, &sr->mc_gregs[PT_NIP]);
608
609 err |= __get_user(msr, &sr->mc_gregs[PT_MSR]);
610 if (err)
611 return 1;
612
613 /* Restore the previous little-endian mode */
614 regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE);
615
616#ifdef CONFIG_ALTIVEC
617 regs->msr &= ~MSR_VEC;
618 if (msr & MSR_VEC) {
619 /* restore altivec registers from the stack */
620 if (__copy_from_user(¤t->thread.ckvr_state, &sr->mc_vregs,
621 sizeof(sr->mc_vregs)) ||
622 __copy_from_user(¤t->thread.vr_state,
623 &tm_sr->mc_vregs,
624 sizeof(sr->mc_vregs)))
625 return 1;
626 current->thread.used_vr = true;
627 } else if (current->thread.used_vr) {
628 memset(¤t->thread.vr_state, 0,
629 ELF_NVRREG * sizeof(vector128));
630 memset(¤t->thread.ckvr_state, 0,
631 ELF_NVRREG * sizeof(vector128));
632 }
633
634 /* Always get VRSAVE back */
635 if (__get_user(current->thread.ckvrsave,
636 (u32 __user *)&sr->mc_vregs[32]) ||
637 __get_user(current->thread.vrsave,
638 (u32 __user *)&tm_sr->mc_vregs[32]))
639 return 1;
640 if (cpu_has_feature(CPU_FTR_ALTIVEC))
641 mtspr(SPRN_VRSAVE, current->thread.ckvrsave);
642#endif /* CONFIG_ALTIVEC */
643
644 regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1);
645
646 if (copy_fpr_from_user(current, &sr->mc_fregs) ||
647 copy_ckfpr_from_user(current, &tm_sr->mc_fregs))
648 return 1;
649
650#ifdef CONFIG_VSX
651 regs->msr &= ~MSR_VSX;
652 if (msr & MSR_VSX) {
653 /*
654 * Restore altivec registers from the stack to a local
655 * buffer, then write this out to the thread_struct
656 */
657 if (copy_vsx_from_user(current, &tm_sr->mc_vsregs) ||
658 copy_ckvsx_from_user(current, &sr->mc_vsregs))
659 return 1;
660 current->thread.used_vsr = true;
661 } else if (current->thread.used_vsr)
662 for (i = 0; i < 32 ; i++) {
663 current->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
664 current->thread.ckfp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
665 }
666#endif /* CONFIG_VSX */
667
668#ifdef CONFIG_SPE
669 /* SPE regs are not checkpointed with TM, so this section is
670 * simply the same as in restore_user_regs().
671 */
672 regs->msr &= ~MSR_SPE;
673 if (msr & MSR_SPE) {
674 if (__copy_from_user(current->thread.evr, &sr->mc_vregs,
675 ELF_NEVRREG * sizeof(u32)))
676 return 1;
677 current->thread.used_spe = true;
678 } else if (current->thread.used_spe)
679 memset(current->thread.evr, 0, ELF_NEVRREG * sizeof(u32));
680
681 /* Always get SPEFSCR back */
682 if (__get_user(current->thread.spefscr, (u32 __user *)&sr->mc_vregs
683 + ELF_NEVRREG))
684 return 1;
685#endif /* CONFIG_SPE */
686
687 /* Get the top half of the MSR from the user context */
688 if (__get_user(msr_hi, &tm_sr->mc_gregs[PT_MSR]))
689 return 1;
690 msr_hi <<= 32;
691 /* If TM bits are set to the reserved value, it's an invalid context */
692 if (MSR_TM_RESV(msr_hi))
693 return 1;
694
695 /*
696 * Disabling preemption, since it is unsafe to be preempted
697 * with MSR[TS] set without recheckpointing.
698 */
699 preempt_disable();
700
701 /*
702 * CAUTION:
703 * After regs->MSR[TS] being updated, make sure that get_user(),
704 * put_user() or similar functions are *not* called. These
705 * functions can generate page faults which will cause the process
706 * to be de-scheduled with MSR[TS] set but without calling
707 * tm_recheckpoint(). This can cause a bug.
708 *
709 * Pull in the MSR TM bits from the user context
710 */
711 regs->msr = (regs->msr & ~MSR_TS_MASK) | (msr_hi & MSR_TS_MASK);
712 /* Now, recheckpoint. This loads up all of the checkpointed (older)
713 * registers, including FP and V[S]Rs. After recheckpointing, the
714 * transactional versions should be loaded.
715 */
716 tm_enable();
717 /* Make sure the transaction is marked as failed */
718 current->thread.tm_texasr |= TEXASR_FS;
719 /* This loads the checkpointed FP/VEC state, if used */
720 tm_recheckpoint(¤t->thread);
721
722 /* This loads the speculative FP/VEC state, if used */
723 msr_check_and_set(msr & (MSR_FP | MSR_VEC));
724 if (msr & MSR_FP) {
725 load_fp_state(¤t->thread.fp_state);
726 regs->msr |= (MSR_FP | current->thread.fpexc_mode);
727 }
728#ifdef CONFIG_ALTIVEC
729 if (msr & MSR_VEC) {
730 load_vr_state(¤t->thread.vr_state);
731 regs->msr |= MSR_VEC;
732 }
733#endif
734
735 preempt_enable();
736
737 return 0;
738}
739#endif
740
741#ifdef CONFIG_PPC64
742
743#define copy_siginfo_to_user copy_siginfo_to_user32
744
745#endif /* CONFIG_PPC64 */
746
747/*
748 * Set up a signal frame for a "real-time" signal handler
749 * (one which gets siginfo).
750 */
751int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
752 struct task_struct *tsk)
753{
754 struct rt_sigframe __user *rt_sf;
755 struct mcontext __user *frame;
756 struct mcontext __user *tm_frame = NULL;
757 void __user *addr;
758 unsigned long newsp = 0;
759 int sigret;
760 unsigned long tramp;
761 struct pt_regs *regs = tsk->thread.regs;
762#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
763 /* Save the thread's msr before get_tm_stackpointer() changes it */
764 unsigned long msr = regs->msr;
765#endif
766
767 BUG_ON(tsk != current);
768
769 /* Set up Signal Frame */
770 /* Put a Real Time Context onto stack */
771 rt_sf = get_sigframe(ksig, get_tm_stackpointer(tsk), sizeof(*rt_sf), 1);
772 addr = rt_sf;
773 if (unlikely(rt_sf == NULL))
774 goto badframe;
775
776 /* Put the siginfo & fill in most of the ucontext */
777 if (copy_siginfo_to_user(&rt_sf->info, &ksig->info)
778 || __put_user(0, &rt_sf->uc.uc_flags)
779 || __save_altstack(&rt_sf->uc.uc_stack, regs->gpr[1])
780 || __put_user(to_user_ptr(&rt_sf->uc.uc_mcontext),
781 &rt_sf->uc.uc_regs)
782 || put_sigset_t(&rt_sf->uc.uc_sigmask, oldset))
783 goto badframe;
784
785 /* Save user registers on the stack */
786 frame = &rt_sf->uc.uc_mcontext;
787 addr = frame;
788 if (vdso32_rt_sigtramp && tsk->mm->context.vdso_base) {
789 sigret = 0;
790 tramp = tsk->mm->context.vdso_base + vdso32_rt_sigtramp;
791 } else {
792 sigret = __NR_rt_sigreturn;
793 tramp = (unsigned long) frame->tramp;
794 }
795
796#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
797 tm_frame = &rt_sf->uc_transact.uc_mcontext;
798 if (MSR_TM_ACTIVE(msr)) {
799 if (__put_user((unsigned long)&rt_sf->uc_transact,
800 &rt_sf->uc.uc_link) ||
801 __put_user((unsigned long)tm_frame,
802 &rt_sf->uc_transact.uc_regs))
803 goto badframe;
804 if (save_tm_user_regs(regs, frame, tm_frame, sigret, msr))
805 goto badframe;
806 }
807 else
808#endif
809 {
810 if (__put_user(0, &rt_sf->uc.uc_link))
811 goto badframe;
812 if (save_user_regs(regs, frame, tm_frame, sigret, 1))
813 goto badframe;
814 }
815 regs->link = tramp;
816
817 tsk->thread.fp_state.fpscr = 0; /* turn off all fp exceptions */
818
819 /* create a stack frame for the caller of the handler */
820 newsp = ((unsigned long)rt_sf) - (__SIGNAL_FRAMESIZE + 16);
821 addr = (void __user *)regs->gpr[1];
822 if (put_user(regs->gpr[1], (u32 __user *)newsp))
823 goto badframe;
824
825 /* Fill registers for signal handler */
826 regs->gpr[1] = newsp;
827 regs->gpr[3] = ksig->sig;
828 regs->gpr[4] = (unsigned long) &rt_sf->info;
829 regs->gpr[5] = (unsigned long) &rt_sf->uc;
830 regs->gpr[6] = (unsigned long) rt_sf;
831 regs->nip = (unsigned long) ksig->ka.sa.sa_handler;
832 /* enter the signal handler in native-endian mode */
833 regs->msr &= ~MSR_LE;
834 regs->msr |= (MSR_KERNEL & MSR_LE);
835 return 0;
836
837badframe:
838 if (show_unhandled_signals)
839 printk_ratelimited(KERN_INFO
840 "%s[%d]: bad frame in handle_rt_signal32: "
841 "%p nip %08lx lr %08lx\n",
842 tsk->comm, tsk->pid,
843 addr, regs->nip, regs->link);
844
845 return 1;
846}
847
848static int do_setcontext(struct ucontext __user *ucp, struct pt_regs *regs, int sig)
849{
850 sigset_t set;
851 struct mcontext __user *mcp;
852
853 if (get_sigset_t(&set, &ucp->uc_sigmask))
854 return -EFAULT;
855#ifdef CONFIG_PPC64
856 {
857 u32 cmcp;
858
859 if (__get_user(cmcp, &ucp->uc_regs))
860 return -EFAULT;
861 mcp = (struct mcontext __user *)(u64)cmcp;
862 /* no need to check access_ok(mcp), since mcp < 4GB */
863 }
864#else
865 if (__get_user(mcp, &ucp->uc_regs))
866 return -EFAULT;
867 if (!access_ok(mcp, sizeof(*mcp)))
868 return -EFAULT;
869#endif
870 set_current_blocked(&set);
871 if (restore_user_regs(regs, mcp, sig))
872 return -EFAULT;
873
874 return 0;
875}
876
877#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
878static int do_setcontext_tm(struct ucontext __user *ucp,
879 struct ucontext __user *tm_ucp,
880 struct pt_regs *regs)
881{
882 sigset_t set;
883 struct mcontext __user *mcp;
884 struct mcontext __user *tm_mcp;
885 u32 cmcp;
886 u32 tm_cmcp;
887
888 if (get_sigset_t(&set, &ucp->uc_sigmask))
889 return -EFAULT;
890
891 if (__get_user(cmcp, &ucp->uc_regs) ||
892 __get_user(tm_cmcp, &tm_ucp->uc_regs))
893 return -EFAULT;
894 mcp = (struct mcontext __user *)(u64)cmcp;
895 tm_mcp = (struct mcontext __user *)(u64)tm_cmcp;
896 /* no need to check access_ok(mcp), since mcp < 4GB */
897
898 set_current_blocked(&set);
899 if (restore_tm_user_regs(regs, mcp, tm_mcp))
900 return -EFAULT;
901
902 return 0;
903}
904#endif
905
906#ifdef CONFIG_PPC64
907COMPAT_SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx,
908 struct ucontext __user *, new_ctx, int, ctx_size)
909#else
910SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx,
911 struct ucontext __user *, new_ctx, long, ctx_size)
912#endif
913{
914 struct pt_regs *regs = current_pt_regs();
915 int ctx_has_vsx_region = 0;
916
917#ifdef CONFIG_PPC64
918 unsigned long new_msr = 0;
919
920 if (new_ctx) {
921 struct mcontext __user *mcp;
922 u32 cmcp;
923
924 /*
925 * Get pointer to the real mcontext. No need for
926 * access_ok since we are dealing with compat
927 * pointers.
928 */
929 if (__get_user(cmcp, &new_ctx->uc_regs))
930 return -EFAULT;
931 mcp = (struct mcontext __user *)(u64)cmcp;
932 if (__get_user(new_msr, &mcp->mc_gregs[PT_MSR]))
933 return -EFAULT;
934 }
935 /*
936 * Check that the context is not smaller than the original
937 * size (with VMX but without VSX)
938 */
939 if (ctx_size < UCONTEXTSIZEWITHOUTVSX)
940 return -EINVAL;
941 /*
942 * If the new context state sets the MSR VSX bits but
943 * it doesn't provide VSX state.
944 */
945 if ((ctx_size < sizeof(struct ucontext)) &&
946 (new_msr & MSR_VSX))
947 return -EINVAL;
948 /* Does the context have enough room to store VSX data? */
949 if (ctx_size >= sizeof(struct ucontext))
950 ctx_has_vsx_region = 1;
951#else
952 /* Context size is for future use. Right now, we only make sure
953 * we are passed something we understand
954 */
955 if (ctx_size < sizeof(struct ucontext))
956 return -EINVAL;
957#endif
958 if (old_ctx != NULL) {
959 struct mcontext __user *mctx;
960
961 /*
962 * old_ctx might not be 16-byte aligned, in which
963 * case old_ctx->uc_mcontext won't be either.
964 * Because we have the old_ctx->uc_pad2 field
965 * before old_ctx->uc_mcontext, we need to round down
966 * from &old_ctx->uc_mcontext to a 16-byte boundary.
967 */
968 mctx = (struct mcontext __user *)
969 ((unsigned long) &old_ctx->uc_mcontext & ~0xfUL);
970 if (!access_ok(old_ctx, ctx_size)
971 || save_user_regs(regs, mctx, NULL, 0, ctx_has_vsx_region)
972 || put_sigset_t(&old_ctx->uc_sigmask, ¤t->blocked)
973 || __put_user(to_user_ptr(mctx), &old_ctx->uc_regs))
974 return -EFAULT;
975 }
976 if (new_ctx == NULL)
977 return 0;
978 if (!access_ok(new_ctx, ctx_size) ||
979 fault_in_pages_readable((u8 __user *)new_ctx, ctx_size))
980 return -EFAULT;
981
982 /*
983 * If we get a fault copying the context into the kernel's
984 * image of the user's registers, we can't just return -EFAULT
985 * because the user's registers will be corrupted. For instance
986 * the NIP value may have been updated but not some of the
987 * other registers. Given that we have done the access_ok
988 * and successfully read the first and last bytes of the region
989 * above, this should only happen in an out-of-memory situation
990 * or if another thread unmaps the region containing the context.
991 * We kill the task with a SIGSEGV in this situation.
992 */
993 if (do_setcontext(new_ctx, regs, 0))
994 do_exit(SIGSEGV);
995
996 set_thread_flag(TIF_RESTOREALL);
997 return 0;
998}
999
1000#ifdef CONFIG_PPC64
1001COMPAT_SYSCALL_DEFINE0(rt_sigreturn)
1002#else
1003SYSCALL_DEFINE0(rt_sigreturn)
1004#endif
1005{
1006 struct rt_sigframe __user *rt_sf;
1007 struct pt_regs *regs = current_pt_regs();
1008 int tm_restore = 0;
1009#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1010 struct ucontext __user *uc_transact;
1011 unsigned long msr_hi;
1012 unsigned long tmp;
1013#endif
1014 /* Always make any pending restarted system calls return -EINTR */
1015 current->restart_block.fn = do_no_restart_syscall;
1016
1017 rt_sf = (struct rt_sigframe __user *)
1018 (regs->gpr[1] + __SIGNAL_FRAMESIZE + 16);
1019 if (!access_ok(rt_sf, sizeof(*rt_sf)))
1020 goto bad;
1021
1022#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1023 /*
1024 * If there is a transactional state then throw it away.
1025 * The purpose of a sigreturn is to destroy all traces of the
1026 * signal frame, this includes any transactional state created
1027 * within in. We only check for suspended as we can never be
1028 * active in the kernel, we are active, there is nothing better to
1029 * do than go ahead and Bad Thing later.
1030 * The cause is not important as there will never be a
1031 * recheckpoint so it's not user visible.
1032 */
1033 if (MSR_TM_SUSPENDED(mfmsr()))
1034 tm_reclaim_current(0);
1035
1036 if (__get_user(tmp, &rt_sf->uc.uc_link))
1037 goto bad;
1038 uc_transact = (struct ucontext __user *)(uintptr_t)tmp;
1039 if (uc_transact) {
1040 u32 cmcp;
1041 struct mcontext __user *mcp;
1042
1043 if (__get_user(cmcp, &uc_transact->uc_regs))
1044 return -EFAULT;
1045 mcp = (struct mcontext __user *)(u64)cmcp;
1046 /* The top 32 bits of the MSR are stashed in the transactional
1047 * ucontext. */
1048 if (__get_user(msr_hi, &mcp->mc_gregs[PT_MSR]))
1049 goto bad;
1050
1051 if (MSR_TM_ACTIVE(msr_hi<<32)) {
1052 /* Trying to start TM on non TM system */
1053 if (!cpu_has_feature(CPU_FTR_TM))
1054 goto bad;
1055 /* We only recheckpoint on return if we're
1056 * transaction.
1057 */
1058 tm_restore = 1;
1059 if (do_setcontext_tm(&rt_sf->uc, uc_transact, regs))
1060 goto bad;
1061 }
1062 }
1063 if (!tm_restore) {
1064 /*
1065 * Unset regs->msr because ucontext MSR TS is not
1066 * set, and recheckpoint was not called. This avoid
1067 * hitting a TM Bad thing at RFID
1068 */
1069 regs->msr &= ~MSR_TS_MASK;
1070 }
1071 /* Fall through, for non-TM restore */
1072#endif
1073 if (!tm_restore)
1074 if (do_setcontext(&rt_sf->uc, regs, 1))
1075 goto bad;
1076
1077 /*
1078 * It's not clear whether or why it is desirable to save the
1079 * sigaltstack setting on signal delivery and restore it on
1080 * signal return. But other architectures do this and we have
1081 * always done it up until now so it is probably better not to
1082 * change it. -- paulus
1083 */
1084#ifdef CONFIG_PPC64
1085 if (compat_restore_altstack(&rt_sf->uc.uc_stack))
1086 goto bad;
1087#else
1088 if (restore_altstack(&rt_sf->uc.uc_stack))
1089 goto bad;
1090#endif
1091 set_thread_flag(TIF_RESTOREALL);
1092 return 0;
1093
1094 bad:
1095 if (show_unhandled_signals)
1096 printk_ratelimited(KERN_INFO
1097 "%s[%d]: bad frame in sys_rt_sigreturn: "
1098 "%p nip %08lx lr %08lx\n",
1099 current->comm, current->pid,
1100 rt_sf, regs->nip, regs->link);
1101
1102 force_sig(SIGSEGV);
1103 return 0;
1104}
1105
1106#ifdef CONFIG_PPC32
1107SYSCALL_DEFINE3(debug_setcontext, struct ucontext __user *, ctx,
1108 int, ndbg, struct sig_dbg_op __user *, dbg)
1109{
1110 struct pt_regs *regs = current_pt_regs();
1111 struct sig_dbg_op op;
1112 int i;
1113 unsigned long new_msr = regs->msr;
1114#ifdef CONFIG_PPC_ADV_DEBUG_REGS
1115 unsigned long new_dbcr0 = current->thread.debug.dbcr0;
1116#endif
1117
1118 for (i=0; i<ndbg; i++) {
1119 if (copy_from_user(&op, dbg + i, sizeof(op)))
1120 return -EFAULT;
1121 switch (op.dbg_type) {
1122 case SIG_DBG_SINGLE_STEPPING:
1123#ifdef CONFIG_PPC_ADV_DEBUG_REGS
1124 if (op.dbg_value) {
1125 new_msr |= MSR_DE;
1126 new_dbcr0 |= (DBCR0_IDM | DBCR0_IC);
1127 } else {
1128 new_dbcr0 &= ~DBCR0_IC;
1129 if (!DBCR_ACTIVE_EVENTS(new_dbcr0,
1130 current->thread.debug.dbcr1)) {
1131 new_msr &= ~MSR_DE;
1132 new_dbcr0 &= ~DBCR0_IDM;
1133 }
1134 }
1135#else
1136 if (op.dbg_value)
1137 new_msr |= MSR_SE;
1138 else
1139 new_msr &= ~MSR_SE;
1140#endif
1141 break;
1142 case SIG_DBG_BRANCH_TRACING:
1143#ifdef CONFIG_PPC_ADV_DEBUG_REGS
1144 return -EINVAL;
1145#else
1146 if (op.dbg_value)
1147 new_msr |= MSR_BE;
1148 else
1149 new_msr &= ~MSR_BE;
1150#endif
1151 break;
1152
1153 default:
1154 return -EINVAL;
1155 }
1156 }
1157
1158 /* We wait until here to actually install the values in the
1159 registers so if we fail in the above loop, it will not
1160 affect the contents of these registers. After this point,
1161 failure is a problem, anyway, and it's very unlikely unless
1162 the user is really doing something wrong. */
1163 regs->msr = new_msr;
1164#ifdef CONFIG_PPC_ADV_DEBUG_REGS
1165 current->thread.debug.dbcr0 = new_dbcr0;
1166#endif
1167
1168 if (!access_ok(ctx, sizeof(*ctx)) ||
1169 fault_in_pages_readable((u8 __user *)ctx, sizeof(*ctx)))
1170 return -EFAULT;
1171
1172 /*
1173 * If we get a fault copying the context into the kernel's
1174 * image of the user's registers, we can't just return -EFAULT
1175 * because the user's registers will be corrupted. For instance
1176 * the NIP value may have been updated but not some of the
1177 * other registers. Given that we have done the access_ok
1178 * and successfully read the first and last bytes of the region
1179 * above, this should only happen in an out-of-memory situation
1180 * or if another thread unmaps the region containing the context.
1181 * We kill the task with a SIGSEGV in this situation.
1182 */
1183 if (do_setcontext(ctx, regs, 1)) {
1184 if (show_unhandled_signals)
1185 printk_ratelimited(KERN_INFO "%s[%d]: bad frame in "
1186 "sys_debug_setcontext: %p nip %08lx "
1187 "lr %08lx\n",
1188 current->comm, current->pid,
1189 ctx, regs->nip, regs->link);
1190
1191 force_sig(SIGSEGV);
1192 goto out;
1193 }
1194
1195 /*
1196 * It's not clear whether or why it is desirable to save the
1197 * sigaltstack setting on signal delivery and restore it on
1198 * signal return. But other architectures do this and we have
1199 * always done it up until now so it is probably better not to
1200 * change it. -- paulus
1201 */
1202 restore_altstack(&ctx->uc_stack);
1203
1204 set_thread_flag(TIF_RESTOREALL);
1205 out:
1206 return 0;
1207}
1208#endif
1209
1210/*
1211 * OK, we're invoking a handler
1212 */
1213int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
1214 struct task_struct *tsk)
1215{
1216 struct sigcontext __user *sc;
1217 struct sigframe __user *frame;
1218 struct mcontext __user *tm_mctx = NULL;
1219 unsigned long newsp = 0;
1220 int sigret;
1221 unsigned long tramp;
1222 struct pt_regs *regs = tsk->thread.regs;
1223#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1224 /* Save the thread's msr before get_tm_stackpointer() changes it */
1225 unsigned long msr = regs->msr;
1226#endif
1227
1228 BUG_ON(tsk != current);
1229
1230 /* Set up Signal Frame */
1231 frame = get_sigframe(ksig, get_tm_stackpointer(tsk), sizeof(*frame), 1);
1232 if (unlikely(frame == NULL))
1233 goto badframe;
1234 sc = (struct sigcontext __user *) &frame->sctx;
1235
1236#if _NSIG != 64
1237#error "Please adjust handle_signal()"
1238#endif
1239 if (__put_user(to_user_ptr(ksig->ka.sa.sa_handler), &sc->handler)
1240 || __put_user(oldset->sig[0], &sc->oldmask)
1241#ifdef CONFIG_PPC64
1242 || __put_user((oldset->sig[0] >> 32), &sc->_unused[3])
1243#else
1244 || __put_user(oldset->sig[1], &sc->_unused[3])
1245#endif
1246 || __put_user(to_user_ptr(&frame->mctx), &sc->regs)
1247 || __put_user(ksig->sig, &sc->signal))
1248 goto badframe;
1249
1250 if (vdso32_sigtramp && tsk->mm->context.vdso_base) {
1251 sigret = 0;
1252 tramp = tsk->mm->context.vdso_base + vdso32_sigtramp;
1253 } else {
1254 sigret = __NR_sigreturn;
1255 tramp = (unsigned long) frame->mctx.tramp;
1256 }
1257
1258#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1259 tm_mctx = &frame->mctx_transact;
1260 if (MSR_TM_ACTIVE(msr)) {
1261 if (save_tm_user_regs(regs, &frame->mctx, &frame->mctx_transact,
1262 sigret, msr))
1263 goto badframe;
1264 }
1265 else
1266#endif
1267 {
1268 if (save_user_regs(regs, &frame->mctx, tm_mctx, sigret, 1))
1269 goto badframe;
1270 }
1271
1272 regs->link = tramp;
1273
1274 tsk->thread.fp_state.fpscr = 0; /* turn off all fp exceptions */
1275
1276 /* create a stack frame for the caller of the handler */
1277 newsp = ((unsigned long)frame) - __SIGNAL_FRAMESIZE;
1278 if (put_user(regs->gpr[1], (u32 __user *)newsp))
1279 goto badframe;
1280
1281 regs->gpr[1] = newsp;
1282 regs->gpr[3] = ksig->sig;
1283 regs->gpr[4] = (unsigned long) sc;
1284 regs->nip = (unsigned long) (unsigned long)ksig->ka.sa.sa_handler;
1285 /* enter the signal handler in big-endian mode */
1286 regs->msr &= ~MSR_LE;
1287 return 0;
1288
1289badframe:
1290 if (show_unhandled_signals)
1291 printk_ratelimited(KERN_INFO
1292 "%s[%d]: bad frame in handle_signal32: "
1293 "%p nip %08lx lr %08lx\n",
1294 tsk->comm, tsk->pid,
1295 frame, regs->nip, regs->link);
1296
1297 return 1;
1298}
1299
1300/*
1301 * Do a signal return; undo the signal stack.
1302 */
1303#ifdef CONFIG_PPC64
1304COMPAT_SYSCALL_DEFINE0(sigreturn)
1305#else
1306SYSCALL_DEFINE0(sigreturn)
1307#endif
1308{
1309 struct pt_regs *regs = current_pt_regs();
1310 struct sigframe __user *sf;
1311 struct sigcontext __user *sc;
1312 struct sigcontext sigctx;
1313 struct mcontext __user *sr;
1314 void __user *addr;
1315 sigset_t set;
1316#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1317 struct mcontext __user *mcp, *tm_mcp;
1318 unsigned long msr_hi;
1319#endif
1320
1321 /* Always make any pending restarted system calls return -EINTR */
1322 current->restart_block.fn = do_no_restart_syscall;
1323
1324 sf = (struct sigframe __user *)(regs->gpr[1] + __SIGNAL_FRAMESIZE);
1325 sc = &sf->sctx;
1326 addr = sc;
1327 if (copy_from_user(&sigctx, sc, sizeof(sigctx)))
1328 goto badframe;
1329
1330#ifdef CONFIG_PPC64
1331 /*
1332 * Note that PPC32 puts the upper 32 bits of the sigmask in the
1333 * unused part of the signal stackframe
1334 */
1335 set.sig[0] = sigctx.oldmask + ((long)(sigctx._unused[3]) << 32);
1336#else
1337 set.sig[0] = sigctx.oldmask;
1338 set.sig[1] = sigctx._unused[3];
1339#endif
1340 set_current_blocked(&set);
1341
1342#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1343 mcp = (struct mcontext __user *)&sf->mctx;
1344 tm_mcp = (struct mcontext __user *)&sf->mctx_transact;
1345 if (__get_user(msr_hi, &tm_mcp->mc_gregs[PT_MSR]))
1346 goto badframe;
1347 if (MSR_TM_ACTIVE(msr_hi<<32)) {
1348 if (!cpu_has_feature(CPU_FTR_TM))
1349 goto badframe;
1350 if (restore_tm_user_regs(regs, mcp, tm_mcp))
1351 goto badframe;
1352 } else
1353#endif
1354 {
1355 sr = (struct mcontext __user *)from_user_ptr(sigctx.regs);
1356 addr = sr;
1357 if (!access_ok(sr, sizeof(*sr))
1358 || restore_user_regs(regs, sr, 1))
1359 goto badframe;
1360 }
1361
1362 set_thread_flag(TIF_RESTOREALL);
1363 return 0;
1364
1365badframe:
1366 if (show_unhandled_signals)
1367 printk_ratelimited(KERN_INFO
1368 "%s[%d]: bad frame in sys_sigreturn: "
1369 "%p nip %08lx lr %08lx\n",
1370 current->comm, current->pid,
1371 addr, regs->nip, regs->link);
1372
1373 force_sig(SIGSEGV);
1374 return 0;
1375}
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 <asm/syscalls_32.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
236unsigned long get_min_sigframe_size_32(void)
237{
238 return max(sizeof(struct rt_sigframe) + __SIGNAL_FRAMESIZE + 16,
239 sizeof(struct sigframe) + __SIGNAL_FRAMESIZE);
240}
241
242/*
243 * Save the current user registers on the user stack.
244 * We only save the altivec/spe registers if the process has used
245 * altivec/spe instructions at some point.
246 */
247static void prepare_save_user_regs(int ctx_has_vsx_region)
248{
249 /* Make sure floating point registers are stored in regs */
250 flush_fp_to_thread(current);
251#ifdef CONFIG_ALTIVEC
252 if (current->thread.used_vr)
253 flush_altivec_to_thread(current);
254 if (cpu_has_feature(CPU_FTR_ALTIVEC))
255 current->thread.vrsave = mfspr(SPRN_VRSAVE);
256#endif
257#ifdef CONFIG_VSX
258 if (current->thread.used_vsr && ctx_has_vsx_region)
259 flush_vsx_to_thread(current);
260#endif
261#ifdef CONFIG_SPE
262 if (current->thread.used_spe)
263 flush_spe_to_thread(current);
264#endif
265}
266
267static int __unsafe_save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
268 struct mcontext __user *tm_frame, int ctx_has_vsx_region)
269{
270 unsigned long msr = regs->msr;
271
272 /* save general registers */
273 unsafe_save_general_regs(regs, frame, failed);
274
275#ifdef CONFIG_ALTIVEC
276 /* save altivec registers */
277 if (current->thread.used_vr) {
278 unsafe_copy_to_user(&frame->mc_vregs, ¤t->thread.vr_state,
279 ELF_NVRREG * sizeof(vector128), failed);
280 /* set MSR_VEC in the saved MSR value to indicate that
281 frame->mc_vregs contains valid data */
282 msr |= MSR_VEC;
283 }
284 /* else assert((regs->msr & MSR_VEC) == 0) */
285
286 /* We always copy to/from vrsave, it's 0 if we don't have or don't
287 * use altivec. Since VSCR only contains 32 bits saved in the least
288 * significant bits of a vector, we "cheat" and stuff VRSAVE in the
289 * most significant bits of that same vector. --BenH
290 * Note that the current VRSAVE value is in the SPR at this point.
291 */
292 unsafe_put_user(current->thread.vrsave, (u32 __user *)&frame->mc_vregs[32],
293 failed);
294#endif /* CONFIG_ALTIVEC */
295 unsafe_copy_fpr_to_user(&frame->mc_fregs, current, failed);
296
297 /*
298 * Clear the MSR VSX bit to indicate there is no valid state attached
299 * to this context, except in the specific case below where we set it.
300 */
301 msr &= ~MSR_VSX;
302#ifdef CONFIG_VSX
303 /*
304 * Copy VSR 0-31 upper half from thread_struct to local
305 * buffer, then write that to userspace. Also set MSR_VSX in
306 * the saved MSR value to indicate that frame->mc_vregs
307 * contains valid data
308 */
309 if (current->thread.used_vsr && ctx_has_vsx_region) {
310 unsafe_copy_vsx_to_user(&frame->mc_vsregs, current, failed);
311 msr |= MSR_VSX;
312 }
313#endif /* CONFIG_VSX */
314#ifdef CONFIG_SPE
315 /* save spe registers */
316 if (current->thread.used_spe) {
317 unsafe_copy_to_user(&frame->mc_vregs, current->thread.evr,
318 ELF_NEVRREG * sizeof(u32), failed);
319 /* set MSR_SPE in the saved MSR value to indicate that
320 frame->mc_vregs contains valid data */
321 msr |= MSR_SPE;
322 }
323 /* else assert((regs->msr & MSR_SPE) == 0) */
324
325 /* We always copy to/from spefscr */
326 unsafe_put_user(current->thread.spefscr,
327 (u32 __user *)&frame->mc_vregs + ELF_NEVRREG, failed);
328#endif /* CONFIG_SPE */
329
330 unsafe_put_user(msr, &frame->mc_gregs[PT_MSR], failed);
331
332 /* We need to write 0 the MSR top 32 bits in the tm frame so that we
333 * can check it on the restore to see if TM is active
334 */
335 if (tm_frame)
336 unsafe_put_user(0, &tm_frame->mc_gregs[PT_MSR], failed);
337
338 return 0;
339
340failed:
341 return 1;
342}
343
344#define unsafe_save_user_regs(regs, frame, tm_frame, has_vsx, label) do { \
345 if (__unsafe_save_user_regs(regs, frame, tm_frame, has_vsx)) \
346 goto label; \
347} while (0)
348
349#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
350/*
351 * Save the current user registers on the user stack.
352 * We only save the altivec/spe registers if the process has used
353 * altivec/spe instructions at some point.
354 * We also save the transactional registers to a second ucontext in the
355 * frame.
356 *
357 * See __unsafe_save_user_regs() and signal_64.c:setup_tm_sigcontexts().
358 */
359static void prepare_save_tm_user_regs(void)
360{
361 WARN_ON(tm_suspend_disabled);
362
363 if (cpu_has_feature(CPU_FTR_ALTIVEC))
364 current->thread.ckvrsave = mfspr(SPRN_VRSAVE);
365}
366
367static int save_tm_user_regs_unsafe(struct pt_regs *regs, struct mcontext __user *frame,
368 struct mcontext __user *tm_frame, unsigned long msr)
369{
370 /* Save both sets of general registers */
371 unsafe_save_general_regs(¤t->thread.ckpt_regs, frame, failed);
372 unsafe_save_general_regs(regs, tm_frame, failed);
373
374 /* Stash the top half of the 64bit MSR into the 32bit MSR word
375 * of the transactional mcontext. This way we have a backward-compatible
376 * MSR in the 'normal' (checkpointed) mcontext and additionally one can
377 * also look at what type of transaction (T or S) was active at the
378 * time of the signal.
379 */
380 unsafe_put_user((msr >> 32), &tm_frame->mc_gregs[PT_MSR], failed);
381
382 /* save altivec registers */
383 if (current->thread.used_vr) {
384 unsafe_copy_to_user(&frame->mc_vregs, ¤t->thread.ckvr_state,
385 ELF_NVRREG * sizeof(vector128), failed);
386 if (msr & MSR_VEC)
387 unsafe_copy_to_user(&tm_frame->mc_vregs,
388 ¤t->thread.vr_state,
389 ELF_NVRREG * sizeof(vector128), failed);
390 else
391 unsafe_copy_to_user(&tm_frame->mc_vregs,
392 ¤t->thread.ckvr_state,
393 ELF_NVRREG * sizeof(vector128), failed);
394
395 /* set MSR_VEC in the saved MSR value to indicate that
396 * frame->mc_vregs contains valid data
397 */
398 msr |= MSR_VEC;
399 }
400
401 /* We always copy to/from vrsave, it's 0 if we don't have or don't
402 * use altivec. Since VSCR only contains 32 bits saved in the least
403 * significant bits of a vector, we "cheat" and stuff VRSAVE in the
404 * most significant bits of that same vector. --BenH
405 */
406 unsafe_put_user(current->thread.ckvrsave,
407 (u32 __user *)&frame->mc_vregs[32], failed);
408 if (msr & MSR_VEC)
409 unsafe_put_user(current->thread.vrsave,
410 (u32 __user *)&tm_frame->mc_vregs[32], failed);
411 else
412 unsafe_put_user(current->thread.ckvrsave,
413 (u32 __user *)&tm_frame->mc_vregs[32], failed);
414
415 unsafe_copy_ckfpr_to_user(&frame->mc_fregs, current, failed);
416 if (msr & MSR_FP)
417 unsafe_copy_fpr_to_user(&tm_frame->mc_fregs, current, failed);
418 else
419 unsafe_copy_ckfpr_to_user(&tm_frame->mc_fregs, current, failed);
420
421 /*
422 * Copy VSR 0-31 upper half from thread_struct to local
423 * buffer, then write that to userspace. Also set MSR_VSX in
424 * the saved MSR value to indicate that frame->mc_vregs
425 * contains valid data
426 */
427 if (current->thread.used_vsr) {
428 unsafe_copy_ckvsx_to_user(&frame->mc_vsregs, current, failed);
429 if (msr & MSR_VSX)
430 unsafe_copy_vsx_to_user(&tm_frame->mc_vsregs, current, failed);
431 else
432 unsafe_copy_ckvsx_to_user(&tm_frame->mc_vsregs, current, failed);
433
434 msr |= MSR_VSX;
435 }
436
437 unsafe_put_user(msr, &frame->mc_gregs[PT_MSR], failed);
438
439 return 0;
440
441failed:
442 return 1;
443}
444#else
445static void prepare_save_tm_user_regs(void) { }
446
447static int save_tm_user_regs_unsafe(struct pt_regs *regs, struct mcontext __user *frame,
448 struct mcontext __user *tm_frame, unsigned long msr)
449{
450 return 0;
451}
452#endif
453
454#define unsafe_save_tm_user_regs(regs, frame, tm_frame, msr, label) do { \
455 if (save_tm_user_regs_unsafe(regs, frame, tm_frame, msr)) \
456 goto label; \
457} while (0)
458
459/*
460 * Restore the current user register values from the user stack,
461 * (except for MSR).
462 */
463static long restore_user_regs(struct pt_regs *regs,
464 struct mcontext __user *sr, int sig)
465{
466 unsigned int save_r2 = 0;
467 unsigned long msr;
468#ifdef CONFIG_VSX
469 int i;
470#endif
471
472 if (!user_read_access_begin(sr, sizeof(*sr)))
473 return 1;
474 /*
475 * restore general registers but not including MSR or SOFTE. Also
476 * take care of keeping r2 (TLS) intact if not a signal
477 */
478 if (!sig)
479 save_r2 = (unsigned int)regs->gpr[2];
480 unsafe_restore_general_regs(regs, sr, failed);
481 set_trap_norestart(regs);
482 unsafe_get_user(msr, &sr->mc_gregs[PT_MSR], failed);
483 if (!sig)
484 regs->gpr[2] = (unsigned long) save_r2;
485
486 /* if doing signal return, restore the previous little-endian mode */
487 if (sig)
488 regs_set_return_msr(regs, (regs->msr & ~MSR_LE) | (msr & MSR_LE));
489
490#ifdef CONFIG_ALTIVEC
491 /*
492 * Force the process to reload the altivec registers from
493 * current->thread when it next does altivec instructions
494 */
495 regs_set_return_msr(regs, regs->msr & ~MSR_VEC);
496 if (msr & MSR_VEC) {
497 /* restore altivec registers from the stack */
498 unsafe_copy_from_user(¤t->thread.vr_state, &sr->mc_vregs,
499 sizeof(sr->mc_vregs), failed);
500 current->thread.used_vr = true;
501 } else if (current->thread.used_vr)
502 memset(¤t->thread.vr_state, 0,
503 ELF_NVRREG * sizeof(vector128));
504
505 /* Always get VRSAVE back */
506 unsafe_get_user(current->thread.vrsave, (u32 __user *)&sr->mc_vregs[32], failed);
507 if (cpu_has_feature(CPU_FTR_ALTIVEC))
508 mtspr(SPRN_VRSAVE, current->thread.vrsave);
509#endif /* CONFIG_ALTIVEC */
510 unsafe_copy_fpr_from_user(current, &sr->mc_fregs, failed);
511
512#ifdef CONFIG_VSX
513 /*
514 * Force the process to reload the VSX registers from
515 * current->thread when it next does VSX instruction.
516 */
517 regs_set_return_msr(regs, regs->msr & ~MSR_VSX);
518 if (msr & MSR_VSX) {
519 /*
520 * Restore altivec registers from the stack to a local
521 * buffer, then write this out to the thread_struct
522 */
523 unsafe_copy_vsx_from_user(current, &sr->mc_vsregs, failed);
524 current->thread.used_vsr = true;
525 } else if (current->thread.used_vsr)
526 for (i = 0; i < 32 ; i++)
527 current->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
528#endif /* CONFIG_VSX */
529 /*
530 * force the process to reload the FP registers from
531 * current->thread when it next does FP instructions
532 */
533 regs_set_return_msr(regs, regs->msr & ~(MSR_FP | MSR_FE0 | MSR_FE1));
534
535#ifdef CONFIG_SPE
536 /*
537 * Force the process to reload the spe registers from
538 * current->thread when it next does spe instructions.
539 * Since this is user ABI, we must enforce the sizing.
540 */
541 BUILD_BUG_ON(sizeof(current->thread.spe) != ELF_NEVRREG * sizeof(u32));
542 regs_set_return_msr(regs, regs->msr & ~MSR_SPE);
543 if (msr & MSR_SPE) {
544 /* restore spe registers from the stack */
545 unsafe_copy_from_user(¤t->thread.spe, &sr->mc_vregs,
546 sizeof(current->thread.spe), failed);
547 current->thread.used_spe = true;
548 } else if (current->thread.used_spe)
549 memset(¤t->thread.spe, 0, sizeof(current->thread.spe));
550
551 /* Always get SPEFSCR back */
552 unsafe_get_user(current->thread.spefscr, (u32 __user *)&sr->mc_vregs + ELF_NEVRREG, failed);
553#endif /* CONFIG_SPE */
554
555 user_read_access_end();
556 return 0;
557
558failed:
559 user_read_access_end();
560 return 1;
561}
562
563#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
564/*
565 * Restore the current user register values from the user stack, except for
566 * MSR, and recheckpoint the original checkpointed register state for processes
567 * in transactions.
568 */
569static long restore_tm_user_regs(struct pt_regs *regs,
570 struct mcontext __user *sr,
571 struct mcontext __user *tm_sr)
572{
573 unsigned long msr, msr_hi;
574 int i;
575
576 if (tm_suspend_disabled)
577 return 1;
578 /*
579 * restore general registers but not including MSR or SOFTE. Also
580 * take care of keeping r2 (TLS) intact if not a signal.
581 * See comment in signal_64.c:restore_tm_sigcontexts();
582 * TFHAR is restored from the checkpointed NIP; TEXASR and TFIAR
583 * were set by the signal delivery.
584 */
585 if (!user_read_access_begin(sr, sizeof(*sr)))
586 return 1;
587
588 unsafe_restore_general_regs(¤t->thread.ckpt_regs, sr, failed);
589 unsafe_get_user(current->thread.tm_tfhar, &sr->mc_gregs[PT_NIP], failed);
590 unsafe_get_user(msr, &sr->mc_gregs[PT_MSR], failed);
591
592 /* Restore the previous little-endian mode */
593 regs_set_return_msr(regs, (regs->msr & ~MSR_LE) | (msr & MSR_LE));
594
595 regs_set_return_msr(regs, regs->msr & ~MSR_VEC);
596 if (msr & MSR_VEC) {
597 /* restore altivec registers from the stack */
598 unsafe_copy_from_user(¤t->thread.ckvr_state, &sr->mc_vregs,
599 sizeof(sr->mc_vregs), failed);
600 current->thread.used_vr = true;
601 } else if (current->thread.used_vr) {
602 memset(¤t->thread.vr_state, 0,
603 ELF_NVRREG * sizeof(vector128));
604 memset(¤t->thread.ckvr_state, 0,
605 ELF_NVRREG * sizeof(vector128));
606 }
607
608 /* Always get VRSAVE back */
609 unsafe_get_user(current->thread.ckvrsave,
610 (u32 __user *)&sr->mc_vregs[32], failed);
611 if (cpu_has_feature(CPU_FTR_ALTIVEC))
612 mtspr(SPRN_VRSAVE, current->thread.ckvrsave);
613
614 regs_set_return_msr(regs, regs->msr & ~(MSR_FP | MSR_FE0 | MSR_FE1));
615
616 unsafe_copy_fpr_from_user(current, &sr->mc_fregs, failed);
617
618 regs_set_return_msr(regs, regs->msr & ~MSR_VSX);
619 if (msr & MSR_VSX) {
620 /*
621 * Restore altivec registers from the stack to a local
622 * buffer, then write this out to the thread_struct
623 */
624 unsafe_copy_ckvsx_from_user(current, &sr->mc_vsregs, failed);
625 current->thread.used_vsr = true;
626 } else if (current->thread.used_vsr)
627 for (i = 0; i < 32 ; i++) {
628 current->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
629 current->thread.ckfp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
630 }
631
632 user_read_access_end();
633
634 if (!user_read_access_begin(tm_sr, sizeof(*tm_sr)))
635 return 1;
636
637 unsafe_restore_general_regs(regs, tm_sr, failed);
638
639 /* restore altivec registers from the stack */
640 if (msr & MSR_VEC)
641 unsafe_copy_from_user(¤t->thread.vr_state, &tm_sr->mc_vregs,
642 sizeof(sr->mc_vregs), failed);
643
644 /* Always get VRSAVE back */
645 unsafe_get_user(current->thread.vrsave,
646 (u32 __user *)&tm_sr->mc_vregs[32], failed);
647
648 unsafe_copy_ckfpr_from_user(current, &tm_sr->mc_fregs, failed);
649
650 if (msr & MSR_VSX) {
651 /*
652 * Restore altivec registers from the stack to a local
653 * buffer, then write this out to the thread_struct
654 */
655 unsafe_copy_vsx_from_user(current, &tm_sr->mc_vsregs, failed);
656 current->thread.used_vsr = true;
657 }
658
659 /* Get the top half of the MSR from the user context */
660 unsafe_get_user(msr_hi, &tm_sr->mc_gregs[PT_MSR], failed);
661 msr_hi <<= 32;
662
663 user_read_access_end();
664
665 /* If TM bits are set to the reserved value, it's an invalid context */
666 if (MSR_TM_RESV(msr_hi))
667 return 1;
668
669 /*
670 * Disabling preemption, since it is unsafe to be preempted
671 * with MSR[TS] set without recheckpointing.
672 */
673 preempt_disable();
674
675 /*
676 * CAUTION:
677 * After regs->MSR[TS] being updated, make sure that get_user(),
678 * put_user() or similar functions are *not* called. These
679 * functions can generate page faults which will cause the process
680 * to be de-scheduled with MSR[TS] set but without calling
681 * tm_recheckpoint(). This can cause a bug.
682 *
683 * Pull in the MSR TM bits from the user context
684 */
685 regs_set_return_msr(regs, (regs->msr & ~MSR_TS_MASK) | (msr_hi & MSR_TS_MASK));
686 /* Now, recheckpoint. This loads up all of the checkpointed (older)
687 * registers, including FP and V[S]Rs. After recheckpointing, the
688 * transactional versions should be loaded.
689 */
690 tm_enable();
691 /* Make sure the transaction is marked as failed */
692 current->thread.tm_texasr |= TEXASR_FS;
693 /* This loads the checkpointed FP/VEC state, if used */
694 tm_recheckpoint(¤t->thread);
695
696 /* This loads the speculative FP/VEC state, if used */
697 msr_check_and_set(msr & (MSR_FP | MSR_VEC));
698 if (msr & MSR_FP) {
699 load_fp_state(¤t->thread.fp_state);
700 regs_set_return_msr(regs, regs->msr | (MSR_FP | current->thread.fpexc_mode));
701 }
702 if (msr & MSR_VEC) {
703 load_vr_state(¤t->thread.vr_state);
704 regs_set_return_msr(regs, regs->msr | MSR_VEC);
705 }
706
707 preempt_enable();
708
709 return 0;
710
711failed:
712 user_read_access_end();
713 return 1;
714}
715#else
716static long restore_tm_user_regs(struct pt_regs *regs, struct mcontext __user *sr,
717 struct mcontext __user *tm_sr)
718{
719 return 0;
720}
721#endif
722
723#ifdef CONFIG_PPC64
724
725#define copy_siginfo_to_user copy_siginfo_to_user32
726
727#endif /* CONFIG_PPC64 */
728
729/*
730 * Set up a signal frame for a "real-time" signal handler
731 * (one which gets siginfo).
732 */
733int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
734 struct task_struct *tsk)
735{
736 struct rt_sigframe __user *frame;
737 struct mcontext __user *mctx;
738 struct mcontext __user *tm_mctx = NULL;
739 unsigned long newsp = 0;
740 unsigned long tramp;
741 struct pt_regs *regs = tsk->thread.regs;
742 /* Save the thread's msr before get_tm_stackpointer() changes it */
743 unsigned long msr = regs->msr;
744
745 /* Set up Signal Frame */
746 frame = get_sigframe(ksig, tsk, sizeof(*frame), 1);
747 mctx = &frame->uc.uc_mcontext;
748#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
749 tm_mctx = &frame->uc_transact.uc_mcontext;
750#endif
751 if (MSR_TM_ACTIVE(msr))
752 prepare_save_tm_user_regs();
753 else
754 prepare_save_user_regs(1);
755
756 if (!user_access_begin(frame, sizeof(*frame)))
757 goto badframe;
758
759 /* Put the siginfo & fill in most of the ucontext */
760 unsafe_put_user(0, &frame->uc.uc_flags, failed);
761#ifdef CONFIG_PPC64
762 unsafe_compat_save_altstack(&frame->uc.uc_stack, regs->gpr[1], failed);
763#else
764 unsafe_save_altstack(&frame->uc.uc_stack, regs->gpr[1], failed);
765#endif
766 unsafe_put_user(to_user_ptr(&frame->uc.uc_mcontext), &frame->uc.uc_regs, failed);
767
768 if (MSR_TM_ACTIVE(msr)) {
769#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
770 unsafe_put_user((unsigned long)&frame->uc_transact,
771 &frame->uc.uc_link, failed);
772 unsafe_put_user((unsigned long)tm_mctx,
773 &frame->uc_transact.uc_regs, failed);
774#endif
775 unsafe_save_tm_user_regs(regs, mctx, tm_mctx, msr, failed);
776 } else {
777 unsafe_put_user(0, &frame->uc.uc_link, failed);
778 unsafe_save_user_regs(regs, mctx, tm_mctx, 1, failed);
779 }
780
781 /* Save user registers on the stack */
782 if (tsk->mm->context.vdso) {
783 tramp = VDSO32_SYMBOL(tsk->mm->context.vdso, sigtramp_rt32);
784 } else {
785 tramp = (unsigned long)mctx->mc_pad;
786 unsafe_put_user(PPC_RAW_LI(_R0, __NR_rt_sigreturn), &mctx->mc_pad[0], failed);
787 unsafe_put_user(PPC_RAW_SC(), &mctx->mc_pad[1], failed);
788 asm("dcbst %y0; sync; icbi %y0; sync" :: "Z" (mctx->mc_pad[0]));
789 }
790 unsafe_put_sigset_t(&frame->uc.uc_sigmask, oldset, failed);
791
792 user_access_end();
793
794 if (copy_siginfo_to_user(&frame->info, &ksig->info))
795 goto badframe;
796
797 regs->link = tramp;
798
799#ifdef CONFIG_PPC_FPU_REGS
800 tsk->thread.fp_state.fpscr = 0; /* turn off all fp exceptions */
801#endif
802
803 /* create a stack frame for the caller of the handler */
804 newsp = ((unsigned long)frame) - (__SIGNAL_FRAMESIZE + 16);
805 if (put_user(regs->gpr[1], (u32 __user *)newsp))
806 goto badframe;
807
808 /* Fill registers for signal handler */
809 regs->gpr[1] = newsp;
810 regs->gpr[3] = ksig->sig;
811 regs->gpr[4] = (unsigned long)&frame->info;
812 regs->gpr[5] = (unsigned long)&frame->uc;
813 regs->gpr[6] = (unsigned long)frame;
814 regs_set_return_ip(regs, (unsigned long) ksig->ka.sa.sa_handler);
815 /* enter the signal handler in native-endian mode */
816 regs_set_return_msr(regs, (regs->msr & ~MSR_LE) | (MSR_KERNEL & MSR_LE));
817
818 return 0;
819
820failed:
821 user_access_end();
822
823badframe:
824 signal_fault(tsk, regs, "handle_rt_signal32", frame);
825
826 return 1;
827}
828
829/*
830 * OK, we're invoking a handler
831 */
832int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
833 struct task_struct *tsk)
834{
835 struct sigcontext __user *sc;
836 struct sigframe __user *frame;
837 struct mcontext __user *mctx;
838 struct mcontext __user *tm_mctx = NULL;
839 unsigned long newsp = 0;
840 unsigned long tramp;
841 struct pt_regs *regs = tsk->thread.regs;
842 /* Save the thread's msr before get_tm_stackpointer() changes it */
843 unsigned long msr = regs->msr;
844
845 /* Set up Signal Frame */
846 frame = get_sigframe(ksig, tsk, sizeof(*frame), 1);
847 mctx = &frame->mctx;
848#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
849 tm_mctx = &frame->mctx_transact;
850#endif
851 if (MSR_TM_ACTIVE(msr))
852 prepare_save_tm_user_regs();
853 else
854 prepare_save_user_regs(1);
855
856 if (!user_access_begin(frame, sizeof(*frame)))
857 goto badframe;
858 sc = (struct sigcontext __user *) &frame->sctx;
859
860#if _NSIG != 64
861#error "Please adjust handle_signal()"
862#endif
863 unsafe_put_user(to_user_ptr(ksig->ka.sa.sa_handler), &sc->handler, failed);
864 unsafe_put_user(oldset->sig[0], &sc->oldmask, failed);
865#ifdef CONFIG_PPC64
866 unsafe_put_user((oldset->sig[0] >> 32), &sc->_unused[3], failed);
867#else
868 unsafe_put_user(oldset->sig[1], &sc->_unused[3], failed);
869#endif
870 unsafe_put_user(to_user_ptr(mctx), &sc->regs, failed);
871 unsafe_put_user(ksig->sig, &sc->signal, failed);
872
873 if (MSR_TM_ACTIVE(msr))
874 unsafe_save_tm_user_regs(regs, mctx, tm_mctx, msr, failed);
875 else
876 unsafe_save_user_regs(regs, mctx, tm_mctx, 1, failed);
877
878 if (tsk->mm->context.vdso) {
879 tramp = VDSO32_SYMBOL(tsk->mm->context.vdso, sigtramp32);
880 } else {
881 tramp = (unsigned long)mctx->mc_pad;
882 unsafe_put_user(PPC_RAW_LI(_R0, __NR_sigreturn), &mctx->mc_pad[0], failed);
883 unsafe_put_user(PPC_RAW_SC(), &mctx->mc_pad[1], failed);
884 asm("dcbst %y0; sync; icbi %y0; sync" :: "Z" (mctx->mc_pad[0]));
885 }
886 user_access_end();
887
888 regs->link = tramp;
889
890#ifdef CONFIG_PPC_FPU_REGS
891 tsk->thread.fp_state.fpscr = 0; /* turn off all fp exceptions */
892#endif
893
894 /* create a stack frame for the caller of the handler */
895 newsp = ((unsigned long)frame) - __SIGNAL_FRAMESIZE;
896 if (put_user(regs->gpr[1], (u32 __user *)newsp))
897 goto badframe;
898
899 regs->gpr[1] = newsp;
900 regs->gpr[3] = ksig->sig;
901 regs->gpr[4] = (unsigned long) sc;
902 regs_set_return_ip(regs, (unsigned long) ksig->ka.sa.sa_handler);
903 /* enter the signal handler in native-endian mode */
904 regs_set_return_msr(regs, (regs->msr & ~MSR_LE) | (MSR_KERNEL & MSR_LE));
905
906 return 0;
907
908failed:
909 user_access_end();
910
911badframe:
912 signal_fault(tsk, regs, "handle_signal32", frame);
913
914 return 1;
915}
916
917static int do_setcontext(struct ucontext __user *ucp, struct pt_regs *regs, int sig)
918{
919 sigset_t set;
920 struct mcontext __user *mcp;
921
922 if (!user_read_access_begin(ucp, sizeof(*ucp)))
923 return -EFAULT;
924
925 unsafe_get_sigset_t(&set, &ucp->uc_sigmask, failed);
926#ifdef CONFIG_PPC64
927 {
928 u32 cmcp;
929
930 unsafe_get_user(cmcp, &ucp->uc_regs, failed);
931 mcp = (struct mcontext __user *)(u64)cmcp;
932 }
933#else
934 unsafe_get_user(mcp, &ucp->uc_regs, failed);
935#endif
936 user_read_access_end();
937
938 set_current_blocked(&set);
939 if (restore_user_regs(regs, mcp, sig))
940 return -EFAULT;
941
942 return 0;
943
944failed:
945 user_read_access_end();
946 return -EFAULT;
947}
948
949#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
950static int do_setcontext_tm(struct ucontext __user *ucp,
951 struct ucontext __user *tm_ucp,
952 struct pt_regs *regs)
953{
954 sigset_t set;
955 struct mcontext __user *mcp;
956 struct mcontext __user *tm_mcp;
957 u32 cmcp;
958 u32 tm_cmcp;
959
960 if (!user_read_access_begin(ucp, sizeof(*ucp)))
961 return -EFAULT;
962
963 unsafe_get_sigset_t(&set, &ucp->uc_sigmask, failed);
964 unsafe_get_user(cmcp, &ucp->uc_regs, failed);
965
966 user_read_access_end();
967
968 if (__get_user(tm_cmcp, &tm_ucp->uc_regs))
969 return -EFAULT;
970 mcp = (struct mcontext __user *)(u64)cmcp;
971 tm_mcp = (struct mcontext __user *)(u64)tm_cmcp;
972 /* no need to check access_ok(mcp), since mcp < 4GB */
973
974 set_current_blocked(&set);
975 if (restore_tm_user_regs(regs, mcp, tm_mcp))
976 return -EFAULT;
977
978 return 0;
979
980failed:
981 user_read_access_end();
982 return -EFAULT;
983}
984#endif
985
986#ifdef CONFIG_PPC64
987COMPAT_SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx,
988 struct ucontext __user *, new_ctx, int, ctx_size)
989#else
990SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx,
991 struct ucontext __user *, new_ctx, long, ctx_size)
992#endif
993{
994 struct pt_regs *regs = current_pt_regs();
995 int ctx_has_vsx_region = 0;
996
997#ifdef CONFIG_PPC64
998 unsigned long new_msr = 0;
999
1000 if (new_ctx) {
1001 struct mcontext __user *mcp;
1002 u32 cmcp;
1003
1004 /*
1005 * Get pointer to the real mcontext. No need for
1006 * access_ok since we are dealing with compat
1007 * pointers.
1008 */
1009 if (__get_user(cmcp, &new_ctx->uc_regs))
1010 return -EFAULT;
1011 mcp = (struct mcontext __user *)(u64)cmcp;
1012 if (__get_user(new_msr, &mcp->mc_gregs[PT_MSR]))
1013 return -EFAULT;
1014 }
1015 /*
1016 * Check that the context is not smaller than the original
1017 * size (with VMX but without VSX)
1018 */
1019 if (ctx_size < UCONTEXTSIZEWITHOUTVSX)
1020 return -EINVAL;
1021 /*
1022 * If the new context state sets the MSR VSX bits but
1023 * it doesn't provide VSX state.
1024 */
1025 if ((ctx_size < sizeof(struct ucontext)) &&
1026 (new_msr & MSR_VSX))
1027 return -EINVAL;
1028 /* Does the context have enough room to store VSX data? */
1029 if (ctx_size >= sizeof(struct ucontext))
1030 ctx_has_vsx_region = 1;
1031#else
1032 /* Context size is for future use. Right now, we only make sure
1033 * we are passed something we understand
1034 */
1035 if (ctx_size < sizeof(struct ucontext))
1036 return -EINVAL;
1037#endif
1038 if (old_ctx != NULL) {
1039 struct mcontext __user *mctx;
1040
1041 /*
1042 * old_ctx might not be 16-byte aligned, in which
1043 * case old_ctx->uc_mcontext won't be either.
1044 * Because we have the old_ctx->uc_pad2 field
1045 * before old_ctx->uc_mcontext, we need to round down
1046 * from &old_ctx->uc_mcontext to a 16-byte boundary.
1047 */
1048 mctx = (struct mcontext __user *)
1049 ((unsigned long) &old_ctx->uc_mcontext & ~0xfUL);
1050 prepare_save_user_regs(ctx_has_vsx_region);
1051 if (!user_write_access_begin(old_ctx, ctx_size))
1052 return -EFAULT;
1053 unsafe_save_user_regs(regs, mctx, NULL, ctx_has_vsx_region, failed);
1054 unsafe_put_sigset_t(&old_ctx->uc_sigmask, ¤t->blocked, failed);
1055 unsafe_put_user(to_user_ptr(mctx), &old_ctx->uc_regs, failed);
1056 user_write_access_end();
1057 }
1058 if (new_ctx == NULL)
1059 return 0;
1060 if (!access_ok(new_ctx, ctx_size) ||
1061 fault_in_readable((char __user *)new_ctx, ctx_size))
1062 return -EFAULT;
1063
1064 /*
1065 * If we get a fault copying the context into the kernel's
1066 * image of the user's registers, we can't just return -EFAULT
1067 * because the user's registers will be corrupted. For instance
1068 * the NIP value may have been updated but not some of the
1069 * other registers. Given that we have done the access_ok
1070 * and successfully read the first and last bytes of the region
1071 * above, this should only happen in an out-of-memory situation
1072 * or if another thread unmaps the region containing the context.
1073 * We kill the task with a SIGSEGV in this situation.
1074 */
1075 if (do_setcontext(new_ctx, regs, 0)) {
1076 force_exit_sig(SIGSEGV);
1077 return -EFAULT;
1078 }
1079
1080 set_thread_flag(TIF_RESTOREALL);
1081 return 0;
1082
1083failed:
1084 user_write_access_end();
1085 return -EFAULT;
1086}
1087
1088#ifdef CONFIG_PPC64
1089COMPAT_SYSCALL_DEFINE0(rt_sigreturn)
1090#else
1091SYSCALL_DEFINE0(rt_sigreturn)
1092#endif
1093{
1094 struct rt_sigframe __user *rt_sf;
1095 struct pt_regs *regs = current_pt_regs();
1096 int tm_restore = 0;
1097#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1098 struct ucontext __user *uc_transact;
1099 unsigned long msr_hi;
1100 unsigned long tmp;
1101#endif
1102 /* Always make any pending restarted system calls return -EINTR */
1103 current->restart_block.fn = do_no_restart_syscall;
1104
1105 rt_sf = (struct rt_sigframe __user *)
1106 (regs->gpr[1] + __SIGNAL_FRAMESIZE + 16);
1107 if (!access_ok(rt_sf, sizeof(*rt_sf)))
1108 goto bad;
1109
1110#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1111 /*
1112 * If there is a transactional state then throw it away.
1113 * The purpose of a sigreturn is to destroy all traces of the
1114 * signal frame, this includes any transactional state created
1115 * within in. We only check for suspended as we can never be
1116 * active in the kernel, we are active, there is nothing better to
1117 * do than go ahead and Bad Thing later.
1118 * The cause is not important as there will never be a
1119 * recheckpoint so it's not user visible.
1120 */
1121 if (MSR_TM_SUSPENDED(mfmsr()))
1122 tm_reclaim_current(0);
1123
1124 if (__get_user(tmp, &rt_sf->uc.uc_link))
1125 goto bad;
1126 uc_transact = (struct ucontext __user *)(uintptr_t)tmp;
1127 if (uc_transact) {
1128 u32 cmcp;
1129 struct mcontext __user *mcp;
1130
1131 if (__get_user(cmcp, &uc_transact->uc_regs))
1132 return -EFAULT;
1133 mcp = (struct mcontext __user *)(u64)cmcp;
1134 /* The top 32 bits of the MSR are stashed in the transactional
1135 * ucontext. */
1136 if (__get_user(msr_hi, &mcp->mc_gregs[PT_MSR]))
1137 goto bad;
1138
1139 if (MSR_TM_ACTIVE(msr_hi<<32)) {
1140 /* Trying to start TM on non TM system */
1141 if (!cpu_has_feature(CPU_FTR_TM))
1142 goto bad;
1143 /* We only recheckpoint on return if we're
1144 * transaction.
1145 */
1146 tm_restore = 1;
1147 if (do_setcontext_tm(&rt_sf->uc, uc_transact, regs))
1148 goto bad;
1149 }
1150 }
1151 if (!tm_restore) {
1152 /*
1153 * Unset regs->msr because ucontext MSR TS is not
1154 * set, and recheckpoint was not called. This avoid
1155 * hitting a TM Bad thing at RFID
1156 */
1157 regs_set_return_msr(regs, regs->msr & ~MSR_TS_MASK);
1158 }
1159 /* Fall through, for non-TM restore */
1160#endif
1161 if (!tm_restore)
1162 if (do_setcontext(&rt_sf->uc, regs, 1))
1163 goto bad;
1164
1165 /*
1166 * It's not clear whether or why it is desirable to save the
1167 * sigaltstack setting on signal delivery and restore it on
1168 * signal return. But other architectures do this and we have
1169 * always done it up until now so it is probably better not to
1170 * change it. -- paulus
1171 */
1172#ifdef CONFIG_PPC64
1173 if (compat_restore_altstack(&rt_sf->uc.uc_stack))
1174 goto bad;
1175#else
1176 if (restore_altstack(&rt_sf->uc.uc_stack))
1177 goto bad;
1178#endif
1179 set_thread_flag(TIF_RESTOREALL);
1180 return 0;
1181
1182 bad:
1183 signal_fault(current, regs, "sys_rt_sigreturn", rt_sf);
1184
1185 force_sig(SIGSEGV);
1186 return 0;
1187}
1188
1189#ifdef CONFIG_PPC32
1190SYSCALL_DEFINE3(debug_setcontext, struct ucontext __user *, ctx,
1191 int, ndbg, struct sig_dbg_op __user *, dbg)
1192{
1193 struct pt_regs *regs = current_pt_regs();
1194 struct sig_dbg_op op;
1195 int i;
1196 unsigned long new_msr = regs->msr;
1197#ifdef CONFIG_PPC_ADV_DEBUG_REGS
1198 unsigned long new_dbcr0 = current->thread.debug.dbcr0;
1199#endif
1200
1201 for (i=0; i<ndbg; i++) {
1202 if (copy_from_user(&op, dbg + i, sizeof(op)))
1203 return -EFAULT;
1204 switch (op.dbg_type) {
1205 case SIG_DBG_SINGLE_STEPPING:
1206#ifdef CONFIG_PPC_ADV_DEBUG_REGS
1207 if (op.dbg_value) {
1208 new_msr |= MSR_DE;
1209 new_dbcr0 |= (DBCR0_IDM | DBCR0_IC);
1210 } else {
1211 new_dbcr0 &= ~DBCR0_IC;
1212 if (!DBCR_ACTIVE_EVENTS(new_dbcr0,
1213 current->thread.debug.dbcr1)) {
1214 new_msr &= ~MSR_DE;
1215 new_dbcr0 &= ~DBCR0_IDM;
1216 }
1217 }
1218#else
1219 if (op.dbg_value)
1220 new_msr |= MSR_SE;
1221 else
1222 new_msr &= ~MSR_SE;
1223#endif
1224 break;
1225 case SIG_DBG_BRANCH_TRACING:
1226#ifdef CONFIG_PPC_ADV_DEBUG_REGS
1227 return -EINVAL;
1228#else
1229 if (op.dbg_value)
1230 new_msr |= MSR_BE;
1231 else
1232 new_msr &= ~MSR_BE;
1233#endif
1234 break;
1235
1236 default:
1237 return -EINVAL;
1238 }
1239 }
1240
1241 /* We wait until here to actually install the values in the
1242 registers so if we fail in the above loop, it will not
1243 affect the contents of these registers. After this point,
1244 failure is a problem, anyway, and it's very unlikely unless
1245 the user is really doing something wrong. */
1246 regs_set_return_msr(regs, new_msr);
1247#ifdef CONFIG_PPC_ADV_DEBUG_REGS
1248 current->thread.debug.dbcr0 = new_dbcr0;
1249#endif
1250
1251 if (!access_ok(ctx, sizeof(*ctx)) ||
1252 fault_in_readable((char __user *)ctx, sizeof(*ctx)))
1253 return -EFAULT;
1254
1255 /*
1256 * If we get a fault copying the context into the kernel's
1257 * image of the user's registers, we can't just return -EFAULT
1258 * because the user's registers will be corrupted. For instance
1259 * the NIP value may have been updated but not some of the
1260 * other registers. Given that we have done the access_ok
1261 * and successfully read the first and last bytes of the region
1262 * above, this should only happen in an out-of-memory situation
1263 * or if another thread unmaps the region containing the context.
1264 * We kill the task with a SIGSEGV in this situation.
1265 */
1266 if (do_setcontext(ctx, regs, 1)) {
1267 signal_fault(current, regs, "sys_debug_setcontext", ctx);
1268
1269 force_sig(SIGSEGV);
1270 goto out;
1271 }
1272
1273 /*
1274 * It's not clear whether or why it is desirable to save the
1275 * sigaltstack setting on signal delivery and restore it on
1276 * signal return. But other architectures do this and we have
1277 * always done it up until now so it is probably better not to
1278 * change it. -- paulus
1279 */
1280 restore_altstack(&ctx->uc_stack);
1281
1282 set_thread_flag(TIF_RESTOREALL);
1283 out:
1284 return 0;
1285}
1286#endif
1287
1288/*
1289 * Do a signal return; undo the signal stack.
1290 */
1291#ifdef CONFIG_PPC64
1292COMPAT_SYSCALL_DEFINE0(sigreturn)
1293#else
1294SYSCALL_DEFINE0(sigreturn)
1295#endif
1296{
1297 struct pt_regs *regs = current_pt_regs();
1298 struct sigframe __user *sf;
1299 struct sigcontext __user *sc;
1300 struct sigcontext sigctx;
1301 struct mcontext __user *sr;
1302 sigset_t set;
1303 struct mcontext __user *mcp;
1304 struct mcontext __user *tm_mcp = NULL;
1305 unsigned long long msr_hi = 0;
1306
1307 /* Always make any pending restarted system calls return -EINTR */
1308 current->restart_block.fn = do_no_restart_syscall;
1309
1310 sf = (struct sigframe __user *)(regs->gpr[1] + __SIGNAL_FRAMESIZE);
1311 sc = &sf->sctx;
1312 if (copy_from_user(&sigctx, sc, sizeof(sigctx)))
1313 goto badframe;
1314
1315#ifdef CONFIG_PPC64
1316 /*
1317 * Note that PPC32 puts the upper 32 bits of the sigmask in the
1318 * unused part of the signal stackframe
1319 */
1320 set.sig[0] = sigctx.oldmask + ((long)(sigctx._unused[3]) << 32);
1321#else
1322 set.sig[0] = sigctx.oldmask;
1323 set.sig[1] = sigctx._unused[3];
1324#endif
1325 set_current_blocked(&set);
1326
1327 mcp = (struct mcontext __user *)&sf->mctx;
1328#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1329 tm_mcp = (struct mcontext __user *)&sf->mctx_transact;
1330 if (__get_user(msr_hi, &tm_mcp->mc_gregs[PT_MSR]))
1331 goto badframe;
1332#endif
1333 if (MSR_TM_ACTIVE(msr_hi<<32)) {
1334 if (!cpu_has_feature(CPU_FTR_TM))
1335 goto badframe;
1336 if (restore_tm_user_regs(regs, mcp, tm_mcp))
1337 goto badframe;
1338 } else {
1339 sr = (struct mcontext __user *)from_user_ptr(sigctx.regs);
1340 if (restore_user_regs(regs, sr, 1)) {
1341 signal_fault(current, regs, "sys_sigreturn", sr);
1342
1343 force_sig(SIGSEGV);
1344 return 0;
1345 }
1346 }
1347
1348 set_thread_flag(TIF_RESTOREALL);
1349 return 0;
1350
1351badframe:
1352 signal_fault(current, regs, "sys_sigreturn", sc);
1353
1354 force_sig(SIGSEGV);
1355 return 0;
1356}