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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 <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}
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}