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