1 // SPDX-License-Identifier: GPL-2.0-or-later
4 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
6 * Derived from "arch/i386/kernel/signal.c"
7 * Copyright (C) 1991, 1992 Linus Torvalds
8 * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
11 #include <linux/sched.h>
13 #include <linux/smp.h>
14 #include <linux/kernel.h>
15 #include <linux/signal.h>
16 #include <linux/errno.h>
17 #include <linux/wait.h>
18 #include <linux/unistd.h>
19 #include <linux/stddef.h>
20 #include <linux/elf.h>
21 #include <linux/ptrace.h>
22 #include <linux/ratelimit.h>
23 #include <linux/syscalls.h>
25 #include <asm/sigcontext.h>
26 #include <asm/ucontext.h>
27 #include <linux/uaccess.h>
28 #include <asm/unistd.h>
29 #include <asm/cacheflush.h>
30 #include <asm/syscalls.h>
32 #include <asm/switch_to.h>
34 #include <asm/asm-prototypes.h>
39 #define GP_REGS_SIZE min(sizeof(elf_gregset_t), sizeof(struct pt_regs))
40 #define FP_REGS_SIZE sizeof(elf_fpregset_t)
42 #define TRAMP_TRACEBACK 3
46 * When we have signals to deliver, we set up on the user stack,
47 * going down from the original stack pointer:
48 * 1) a rt_sigframe struct which contains the ucontext
49 * 2) a gap of __SIGNAL_FRAMESIZE bytes which acts as a dummy caller
50 * frame for the signal handler.
54 /* sys_rt_sigreturn requires the ucontext be the first field */
56 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
57 struct ucontext uc_transact;
59 unsigned long _unused[2];
60 unsigned int tramp[TRAMP_SIZE];
61 struct siginfo __user *pinfo;
64 /* New 64 bit little-endian ABI allows redzone of 512 bytes below sp */
65 char abigap[USER_REDZONE_SIZE];
66 } __attribute__ ((aligned (16)));
68 static const char fmt32[] = KERN_INFO \
69 "%s[%d]: bad frame in %s: %08lx nip %08lx lr %08lx\n";
70 static const char fmt64[] = KERN_INFO \
71 "%s[%d]: bad frame in %s: %016lx nip %016lx lr %016lx\n";
74 * This computes a quad word aligned pointer inside the vmx_reserve array
75 * element. For historical reasons sigcontext might not be quad word aligned,
76 * but the location we write the VMX regs to must be. See the comment in
77 * sigcontext for more detail.
80 static elf_vrreg_t __user *sigcontext_vmx_regs(struct sigcontext __user *sc)
82 return (elf_vrreg_t __user *) (((unsigned long)sc->vmx_reserve + 15) & ~0xful);
87 * Set up the sigcontext for the signal frame.
90 static long setup_sigcontext(struct sigcontext __user *sc,
91 struct task_struct *tsk, int signr, sigset_t *set,
92 unsigned long handler, int ctx_has_vsx_region)
94 /* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the
95 * process never used altivec yet (MSR_VEC is zero in pt_regs of
96 * the context). This is very important because we must ensure we
97 * don't lose the VRSAVE content that may have been set prior to
98 * the process doing its first vector operation
99 * Userland shall check AT_HWCAP to know whether it can rely on the
100 * v_regs pointer or not
102 #ifdef CONFIG_ALTIVEC
103 elf_vrreg_t __user *v_regs = sigcontext_vmx_regs(sc);
104 unsigned long vrsave;
106 struct pt_regs *regs = tsk->thread.regs;
107 unsigned long msr = regs->msr;
109 /* Force usr to alway see softe as 1 (interrupts enabled) */
110 unsigned long softe = 0x1;
112 BUG_ON(tsk != current);
114 #ifdef CONFIG_ALTIVEC
115 err |= __put_user(v_regs, &sc->v_regs);
117 /* save altivec registers */
118 if (tsk->thread.used_vr) {
119 flush_altivec_to_thread(tsk);
120 /* Copy 33 vec registers (vr0..31 and vscr) to the stack */
121 err |= __copy_to_user(v_regs, &tsk->thread.vr_state,
122 33 * sizeof(vector128));
123 /* set MSR_VEC in the MSR value in the frame to indicate that sc->v_reg)
124 * contains valid data.
128 /* We always copy to/from vrsave, it's 0 if we don't have or don't
132 if (cpu_has_feature(CPU_FTR_ALTIVEC)) {
133 vrsave = mfspr(SPRN_VRSAVE);
134 tsk->thread.vrsave = vrsave;
137 err |= __put_user(vrsave, (u32 __user *)&v_regs[33]);
138 #else /* CONFIG_ALTIVEC */
139 err |= __put_user(0, &sc->v_regs);
140 #endif /* CONFIG_ALTIVEC */
141 flush_fp_to_thread(tsk);
142 /* copy fpr regs and fpscr */
143 err |= copy_fpr_to_user(&sc->fp_regs, tsk);
146 * Clear the MSR VSX bit to indicate there is no valid state attached
147 * to this context, except in the specific case below where we set it.
152 * Copy VSX low doubleword to local buffer for formatting,
153 * then out to userspace. Update v_regs to point after the
156 if (tsk->thread.used_vsr && ctx_has_vsx_region) {
157 flush_vsx_to_thread(tsk);
158 v_regs += ELF_NVRREG;
159 err |= copy_vsx_to_user(v_regs, tsk);
160 /* set MSR_VSX in the MSR value in the frame to
161 * indicate that sc->vs_reg) contains valid data.
165 #endif /* CONFIG_VSX */
166 err |= __put_user(&sc->gp_regs, &sc->regs);
167 WARN_ON(!FULL_REGS(regs));
168 err |= __copy_to_user(&sc->gp_regs, regs, GP_REGS_SIZE);
169 err |= __put_user(msr, &sc->gp_regs[PT_MSR]);
170 err |= __put_user(softe, &sc->gp_regs[PT_SOFTE]);
171 err |= __put_user(signr, &sc->signal);
172 err |= __put_user(handler, &sc->handler);
174 err |= __put_user(set->sig[0], &sc->oldmask);
179 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
181 * As above, but Transactional Memory is in use, so deliver sigcontexts
182 * containing checkpointed and transactional register states.
184 * To do this, we treclaim (done before entering here) to gather both sets of
185 * registers and set up the 'normal' sigcontext registers with rolled-back
186 * register values such that a simple signal handler sees a correct
187 * checkpointed register state. If interested, a TM-aware sighandler can
188 * examine the transactional registers in the 2nd sigcontext to determine the
189 * real origin of the signal.
191 static long setup_tm_sigcontexts(struct sigcontext __user *sc,
192 struct sigcontext __user *tm_sc,
193 struct task_struct *tsk,
194 int signr, sigset_t *set, unsigned long handler,
197 /* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the
198 * process never used altivec yet (MSR_VEC is zero in pt_regs of
199 * the context). This is very important because we must ensure we
200 * don't lose the VRSAVE content that may have been set prior to
201 * the process doing its first vector operation
202 * Userland shall check AT_HWCAP to know wether it can rely on the
203 * v_regs pointer or not.
205 #ifdef CONFIG_ALTIVEC
206 elf_vrreg_t __user *v_regs = sigcontext_vmx_regs(sc);
207 elf_vrreg_t __user *tm_v_regs = sigcontext_vmx_regs(tm_sc);
209 struct pt_regs *regs = tsk->thread.regs;
212 BUG_ON(tsk != current);
214 BUG_ON(!MSR_TM_ACTIVE(msr));
216 WARN_ON(tm_suspend_disabled);
218 /* Restore checkpointed FP, VEC, and VSX bits from ckpt_regs as
219 * it contains the correct FP, VEC, VSX state after we treclaimed
220 * the transaction and giveup_all() was called on reclaiming.
222 msr |= tsk->thread.ckpt_regs.msr & (MSR_FP | MSR_VEC | MSR_VSX);
224 #ifdef CONFIG_ALTIVEC
225 err |= __put_user(v_regs, &sc->v_regs);
226 err |= __put_user(tm_v_regs, &tm_sc->v_regs);
228 /* save altivec registers */
229 if (tsk->thread.used_vr) {
230 /* Copy 33 vec registers (vr0..31 and vscr) to the stack */
231 err |= __copy_to_user(v_regs, &tsk->thread.ckvr_state,
232 33 * sizeof(vector128));
233 /* If VEC was enabled there are transactional VRs valid too,
234 * else they're a copy of the checkpointed VRs.
237 err |= __copy_to_user(tm_v_regs,
238 &tsk->thread.vr_state,
239 33 * sizeof(vector128));
241 err |= __copy_to_user(tm_v_regs,
242 &tsk->thread.ckvr_state,
243 33 * sizeof(vector128));
245 /* set MSR_VEC in the MSR value in the frame to indicate
246 * that sc->v_reg contains valid data.
250 /* We always copy to/from vrsave, it's 0 if we don't have or don't
253 if (cpu_has_feature(CPU_FTR_ALTIVEC))
254 tsk->thread.ckvrsave = mfspr(SPRN_VRSAVE);
255 err |= __put_user(tsk->thread.ckvrsave, (u32 __user *)&v_regs[33]);
257 err |= __put_user(tsk->thread.vrsave,
258 (u32 __user *)&tm_v_regs[33]);
260 err |= __put_user(tsk->thread.ckvrsave,
261 (u32 __user *)&tm_v_regs[33]);
263 #else /* CONFIG_ALTIVEC */
264 err |= __put_user(0, &sc->v_regs);
265 err |= __put_user(0, &tm_sc->v_regs);
266 #endif /* CONFIG_ALTIVEC */
268 /* copy fpr regs and fpscr */
269 err |= copy_ckfpr_to_user(&sc->fp_regs, tsk);
271 err |= copy_fpr_to_user(&tm_sc->fp_regs, tsk);
273 err |= copy_ckfpr_to_user(&tm_sc->fp_regs, tsk);
277 * Copy VSX low doubleword to local buffer for formatting,
278 * then out to userspace. Update v_regs to point after the
281 if (tsk->thread.used_vsr) {
282 v_regs += ELF_NVRREG;
283 tm_v_regs += ELF_NVRREG;
285 err |= copy_ckvsx_to_user(v_regs, tsk);
288 err |= copy_vsx_to_user(tm_v_regs, tsk);
290 err |= copy_ckvsx_to_user(tm_v_regs, tsk);
292 /* set MSR_VSX in the MSR value in the frame to
293 * indicate that sc->vs_reg) contains valid data.
297 #endif /* CONFIG_VSX */
299 err |= __put_user(&sc->gp_regs, &sc->regs);
300 err |= __put_user(&tm_sc->gp_regs, &tm_sc->regs);
301 WARN_ON(!FULL_REGS(regs));
302 err |= __copy_to_user(&tm_sc->gp_regs, regs, GP_REGS_SIZE);
303 err |= __copy_to_user(&sc->gp_regs,
304 &tsk->thread.ckpt_regs, GP_REGS_SIZE);
305 err |= __put_user(msr, &tm_sc->gp_regs[PT_MSR]);
306 err |= __put_user(msr, &sc->gp_regs[PT_MSR]);
307 err |= __put_user(signr, &sc->signal);
308 err |= __put_user(handler, &sc->handler);
310 err |= __put_user(set->sig[0], &sc->oldmask);
317 * Restore the sigcontext from the signal frame.
320 static long restore_sigcontext(struct task_struct *tsk, sigset_t *set, int sig,
321 struct sigcontext __user *sc)
323 #ifdef CONFIG_ALTIVEC
324 elf_vrreg_t __user *v_regs;
326 unsigned long err = 0;
327 unsigned long save_r13 = 0;
329 struct pt_regs *regs = tsk->thread.regs;
334 BUG_ON(tsk != current);
336 /* If this is not a signal return, we preserve the TLS in r13 */
338 save_r13 = regs->gpr[13];
341 err |= __copy_from_user(regs->gpr, sc->gp_regs, sizeof(regs->gpr));
342 err |= __get_user(regs->nip, &sc->gp_regs[PT_NIP]);
343 /* get MSR separately, transfer the LE bit if doing signal return */
344 err |= __get_user(msr, &sc->gp_regs[PT_MSR]);
346 regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE);
347 err |= __get_user(regs->orig_gpr3, &sc->gp_regs[PT_ORIG_R3]);
348 err |= __get_user(regs->ctr, &sc->gp_regs[PT_CTR]);
349 err |= __get_user(regs->link, &sc->gp_regs[PT_LNK]);
350 err |= __get_user(regs->xer, &sc->gp_regs[PT_XER]);
351 err |= __get_user(regs->ccr, &sc->gp_regs[PT_CCR]);
352 /* Don't allow userspace to set SOFTE */
353 set_trap_norestart(regs);
354 err |= __get_user(regs->dar, &sc->gp_regs[PT_DAR]);
355 err |= __get_user(regs->dsisr, &sc->gp_regs[PT_DSISR]);
356 err |= __get_user(regs->result, &sc->gp_regs[PT_RESULT]);
359 regs->gpr[13] = save_r13;
361 err |= __get_user(set->sig[0], &sc->oldmask);
364 * Force reload of FP/VEC.
365 * This has to be done before copying stuff into tsk->thread.fpr/vr
366 * for the reasons explained in the previous comment.
368 regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC | MSR_VSX);
370 #ifdef CONFIG_ALTIVEC
371 err |= __get_user(v_regs, &sc->v_regs);
374 if (v_regs && !access_ok(v_regs, 34 * sizeof(vector128)))
376 /* Copy 33 vec registers (vr0..31 and vscr) from the stack */
377 if (v_regs != NULL && (msr & MSR_VEC) != 0) {
378 err |= __copy_from_user(&tsk->thread.vr_state, v_regs,
379 33 * sizeof(vector128));
380 tsk->thread.used_vr = true;
381 } else if (tsk->thread.used_vr) {
382 memset(&tsk->thread.vr_state, 0, 33 * sizeof(vector128));
384 /* Always get VRSAVE back */
386 err |= __get_user(tsk->thread.vrsave, (u32 __user *)&v_regs[33]);
388 tsk->thread.vrsave = 0;
389 if (cpu_has_feature(CPU_FTR_ALTIVEC))
390 mtspr(SPRN_VRSAVE, tsk->thread.vrsave);
391 #endif /* CONFIG_ALTIVEC */
392 /* restore floating point */
393 err |= copy_fpr_from_user(tsk, &sc->fp_regs);
396 * Get additional VSX data. Update v_regs to point after the
397 * VMX data. Copy VSX low doubleword from userspace to local
398 * buffer for formatting, then into the taskstruct.
400 v_regs += ELF_NVRREG;
401 if ((msr & MSR_VSX) != 0) {
402 err |= copy_vsx_from_user(tsk, v_regs);
403 tsk->thread.used_vsr = true;
405 for (i = 0; i < 32 ; i++)
406 tsk->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
412 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
414 * Restore the two sigcontexts from the frame of a transactional processes.
417 static long restore_tm_sigcontexts(struct task_struct *tsk,
418 struct sigcontext __user *sc,
419 struct sigcontext __user *tm_sc)
421 #ifdef CONFIG_ALTIVEC
422 elf_vrreg_t __user *v_regs, *tm_v_regs;
424 unsigned long err = 0;
426 struct pt_regs *regs = tsk->thread.regs;
431 BUG_ON(tsk != current);
433 if (tm_suspend_disabled)
437 err |= __copy_from_user(regs->gpr, tm_sc->gp_regs, sizeof(regs->gpr));
438 err |= __copy_from_user(&tsk->thread.ckpt_regs, sc->gp_regs,
442 * TFHAR is restored from the checkpointed 'wound-back' ucontext's NIP.
443 * TEXASR was set by the signal delivery reclaim, as was TFIAR.
444 * Users doing anything abhorrent like thread-switching w/ signals for
445 * TM-Suspended code will have to back TEXASR/TFIAR up themselves.
446 * For the case of getting a signal and simply returning from it,
447 * we don't need to re-copy them here.
449 err |= __get_user(regs->nip, &tm_sc->gp_regs[PT_NIP]);
450 err |= __get_user(tsk->thread.tm_tfhar, &sc->gp_regs[PT_NIP]);
452 /* get MSR separately, transfer the LE bit if doing signal return */
453 err |= __get_user(msr, &sc->gp_regs[PT_MSR]);
454 /* Don't allow reserved mode. */
455 if (MSR_TM_RESV(msr))
458 /* pull in MSR LE from user context */
459 regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE);
461 /* The following non-GPR non-FPR non-VR state is also checkpointed: */
462 err |= __get_user(regs->ctr, &tm_sc->gp_regs[PT_CTR]);
463 err |= __get_user(regs->link, &tm_sc->gp_regs[PT_LNK]);
464 err |= __get_user(regs->xer, &tm_sc->gp_regs[PT_XER]);
465 err |= __get_user(regs->ccr, &tm_sc->gp_regs[PT_CCR]);
466 err |= __get_user(tsk->thread.ckpt_regs.ctr,
467 &sc->gp_regs[PT_CTR]);
468 err |= __get_user(tsk->thread.ckpt_regs.link,
469 &sc->gp_regs[PT_LNK]);
470 err |= __get_user(tsk->thread.ckpt_regs.xer,
471 &sc->gp_regs[PT_XER]);
472 err |= __get_user(tsk->thread.ckpt_regs.ccr,
473 &sc->gp_regs[PT_CCR]);
474 /* Don't allow userspace to set SOFTE */
475 set_trap_norestart(regs);
476 /* These regs are not checkpointed; they can go in 'regs'. */
477 err |= __get_user(regs->dar, &sc->gp_regs[PT_DAR]);
478 err |= __get_user(regs->dsisr, &sc->gp_regs[PT_DSISR]);
479 err |= __get_user(regs->result, &sc->gp_regs[PT_RESULT]);
482 * Force reload of FP/VEC.
483 * This has to be done before copying stuff into tsk->thread.fpr/vr
484 * for the reasons explained in the previous comment.
486 regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC | MSR_VSX);
488 #ifdef CONFIG_ALTIVEC
489 err |= __get_user(v_regs, &sc->v_regs);
490 err |= __get_user(tm_v_regs, &tm_sc->v_regs);
493 if (v_regs && !access_ok(v_regs, 34 * sizeof(vector128)))
495 if (tm_v_regs && !access_ok(tm_v_regs, 34 * sizeof(vector128)))
497 /* Copy 33 vec registers (vr0..31 and vscr) from the stack */
498 if (v_regs != NULL && tm_v_regs != NULL && (msr & MSR_VEC) != 0) {
499 err |= __copy_from_user(&tsk->thread.ckvr_state, v_regs,
500 33 * sizeof(vector128));
501 err |= __copy_from_user(&tsk->thread.vr_state, tm_v_regs,
502 33 * sizeof(vector128));
503 current->thread.used_vr = true;
505 else if (tsk->thread.used_vr) {
506 memset(&tsk->thread.vr_state, 0, 33 * sizeof(vector128));
507 memset(&tsk->thread.ckvr_state, 0, 33 * sizeof(vector128));
509 /* Always get VRSAVE back */
510 if (v_regs != NULL && tm_v_regs != NULL) {
511 err |= __get_user(tsk->thread.ckvrsave,
512 (u32 __user *)&v_regs[33]);
513 err |= __get_user(tsk->thread.vrsave,
514 (u32 __user *)&tm_v_regs[33]);
517 tsk->thread.vrsave = 0;
518 tsk->thread.ckvrsave = 0;
520 if (cpu_has_feature(CPU_FTR_ALTIVEC))
521 mtspr(SPRN_VRSAVE, tsk->thread.vrsave);
522 #endif /* CONFIG_ALTIVEC */
523 /* restore floating point */
524 err |= copy_fpr_from_user(tsk, &tm_sc->fp_regs);
525 err |= copy_ckfpr_from_user(tsk, &sc->fp_regs);
528 * Get additional VSX data. Update v_regs to point after the
529 * VMX data. Copy VSX low doubleword from userspace to local
530 * buffer for formatting, then into the taskstruct.
532 if (v_regs && ((msr & MSR_VSX) != 0)) {
533 v_regs += ELF_NVRREG;
534 tm_v_regs += ELF_NVRREG;
535 err |= copy_vsx_from_user(tsk, tm_v_regs);
536 err |= copy_ckvsx_from_user(tsk, v_regs);
537 tsk->thread.used_vsr = true;
539 for (i = 0; i < 32 ; i++) {
540 tsk->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
541 tsk->thread.ckfp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
546 /* Make sure the transaction is marked as failed */
547 tsk->thread.tm_texasr |= TEXASR_FS;
550 * Disabling preemption, since it is unsafe to be preempted
551 * with MSR[TS] set without recheckpointing.
555 /* pull in MSR TS bits from user context */
556 regs->msr |= msr & MSR_TS_MASK;
559 * Ensure that TM is enabled in regs->msr before we leave the signal
560 * handler. It could be the case that (a) user disabled the TM bit
561 * through the manipulation of the MSR bits in uc_mcontext or (b) the
562 * TM bit was disabled because a sufficient number of context switches
563 * happened whilst in the signal handler and load_tm overflowed,
564 * disabling the TM bit. In either case we can end up with an illegal
565 * TM state leading to a TM Bad Thing when we return to userspace.
568 * After regs->MSR[TS] being updated, make sure that get_user(),
569 * put_user() or similar functions are *not* called. These
570 * functions can generate page faults which will cause the process
571 * to be de-scheduled with MSR[TS] set but without calling
572 * tm_recheckpoint(). This can cause a bug.
576 /* This loads the checkpointed FP/VEC state, if used */
577 tm_recheckpoint(&tsk->thread);
579 msr_check_and_set(msr & (MSR_FP | MSR_VEC));
581 load_fp_state(&tsk->thread.fp_state);
582 regs->msr |= (MSR_FP | tsk->thread.fpexc_mode);
585 load_vr_state(&tsk->thread.vr_state);
586 regs->msr |= MSR_VEC;
596 * Setup the trampoline code on the stack
598 static long setup_trampoline(unsigned int syscall, unsigned int __user *tramp)
603 /* addi r1, r1, __SIGNAL_FRAMESIZE # Pop the dummy stackframe */
604 err |= __put_user(PPC_INST_ADDI | __PPC_RT(R1) | __PPC_RA(R1) |
605 (__SIGNAL_FRAMESIZE & 0xffff), &tramp[0]);
606 /* li r0, __NR_[rt_]sigreturn| */
607 err |= __put_user(PPC_INST_ADDI | (syscall & 0xffff), &tramp[1]);
609 err |= __put_user(PPC_INST_SC, &tramp[2]);
611 /* Minimal traceback info */
612 for (i=TRAMP_TRACEBACK; i < TRAMP_SIZE ;i++)
613 err |= __put_user(0, &tramp[i]);
616 flush_icache_range((unsigned long) &tramp[0],
617 (unsigned long) &tramp[TRAMP_SIZE]);
623 * Userspace code may pass a ucontext which doesn't include VSX added
624 * at the end. We need to check for this case.
626 #define UCONTEXTSIZEWITHOUTVSX \
627 (sizeof(struct ucontext) - 32*sizeof(long))
630 * Handle {get,set,swap}_context operations
632 SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx,
633 struct ucontext __user *, new_ctx, long, ctx_size)
637 unsigned long new_msr = 0;
638 int ctx_has_vsx_region = 0;
641 get_user(new_msr, &new_ctx->uc_mcontext.gp_regs[PT_MSR]))
644 * Check that the context is not smaller than the original
645 * size (with VMX but without VSX)
647 if (ctx_size < UCONTEXTSIZEWITHOUTVSX)
650 * If the new context state sets the MSR VSX bits but
651 * it doesn't provide VSX state.
653 if ((ctx_size < sizeof(struct ucontext)) &&
656 /* Does the context have enough room to store VSX data? */
657 if (ctx_size >= sizeof(struct ucontext))
658 ctx_has_vsx_region = 1;
660 if (old_ctx != NULL) {
661 if (!access_ok(old_ctx, ctx_size)
662 || setup_sigcontext(&old_ctx->uc_mcontext, current, 0, NULL, 0,
664 || __copy_to_user(&old_ctx->uc_sigmask,
665 ¤t->blocked, sizeof(sigset_t)))
670 if (!access_ok(new_ctx, ctx_size)
671 || __get_user(tmp, (u8 __user *) new_ctx)
672 || __get_user(tmp, (u8 __user *) new_ctx + ctx_size - 1))
676 * If we get a fault copying the context into the kernel's
677 * image of the user's registers, we can't just return -EFAULT
678 * because the user's registers will be corrupted. For instance
679 * the NIP value may have been updated but not some of the
680 * other registers. Given that we have done the access_ok
681 * and successfully read the first and last bytes of the region
682 * above, this should only happen in an out-of-memory situation
683 * or if another thread unmaps the region containing the context.
684 * We kill the task with a SIGSEGV in this situation.
687 if (__copy_from_user(&set, &new_ctx->uc_sigmask, sizeof(set)))
689 set_current_blocked(&set);
690 if (restore_sigcontext(current, NULL, 0, &new_ctx->uc_mcontext))
693 /* This returns like rt_sigreturn */
694 set_thread_flag(TIF_RESTOREALL);
700 * Do a signal return; undo the signal stack.
703 SYSCALL_DEFINE0(rt_sigreturn)
705 struct pt_regs *regs = current_pt_regs();
706 struct ucontext __user *uc = (struct ucontext __user *)regs->gpr[1];
708 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
712 /* Always make any pending restarted system calls return -EINTR */
713 current->restart_block.fn = do_no_restart_syscall;
715 if (!access_ok(uc, sizeof(*uc)))
718 if (__copy_from_user(&set, &uc->uc_sigmask, sizeof(set)))
720 set_current_blocked(&set);
722 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
724 * If there is a transactional state then throw it away.
725 * The purpose of a sigreturn is to destroy all traces of the
726 * signal frame, this includes any transactional state created
727 * within in. We only check for suspended as we can never be
728 * active in the kernel, we are active, there is nothing better to
729 * do than go ahead and Bad Thing later.
730 * The cause is not important as there will never be a
731 * recheckpoint so it's not user visible.
733 if (MSR_TM_SUSPENDED(mfmsr()))
734 tm_reclaim_current(0);
737 * Disable MSR[TS] bit also, so, if there is an exception in the
738 * code below (as a page fault in copy_ckvsx_to_user()), it does
739 * not recheckpoint this task if there was a context switch inside
742 * A major page fault can indirectly call schedule(). A reschedule
743 * process in the middle of an exception can have a side effect
744 * (Changing the CPU MSR[TS] state), since schedule() is called
745 * with the CPU MSR[TS] disable and returns with MSR[TS]=Suspended
746 * (switch_to() calls tm_recheckpoint() for the 'new' process). In
747 * this case, the process continues to be the same in the CPU, but
748 * the CPU state just changed.
750 * This can cause a TM Bad Thing, since the MSR in the stack will
751 * have the MSR[TS]=0, and this is what will be used to RFID.
753 * Clearing MSR[TS] state here will avoid a recheckpoint if there
754 * is any process reschedule in kernel space. The MSR[TS] state
755 * does not need to be saved also, since it will be replaced with
756 * the MSR[TS] that came from user context later, at
757 * restore_tm_sigcontexts.
759 regs->msr &= ~MSR_TS_MASK;
761 if (__get_user(msr, &uc->uc_mcontext.gp_regs[PT_MSR]))
763 if (MSR_TM_ACTIVE(msr)) {
764 /* We recheckpoint on return. */
765 struct ucontext __user *uc_transact;
767 /* Trying to start TM on non TM system */
768 if (!cpu_has_feature(CPU_FTR_TM))
771 if (__get_user(uc_transact, &uc->uc_link))
773 if (restore_tm_sigcontexts(current, &uc->uc_mcontext,
774 &uc_transact->uc_mcontext))
780 * Fall through, for non-TM restore
782 * Unset MSR[TS] on the thread regs since MSR from user
783 * context does not have MSR active, and recheckpoint was
784 * not called since restore_tm_sigcontexts() was not called
787 * If not unsetting it, the code can RFID to userspace with
788 * MSR[TS] set, but without CPU in the proper state,
789 * causing a TM bad thing.
791 current->thread.regs->msr &= ~MSR_TS_MASK;
792 if (restore_sigcontext(current, NULL, 1, &uc->uc_mcontext))
796 if (restore_altstack(&uc->uc_stack))
799 set_thread_flag(TIF_RESTOREALL);
803 if (show_unhandled_signals)
804 printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32,
805 current->comm, current->pid, "rt_sigreturn",
806 (long)uc, regs->nip, regs->link);
812 int handle_rt_signal64(struct ksignal *ksig, sigset_t *set,
813 struct task_struct *tsk)
815 struct rt_sigframe __user *frame;
816 unsigned long newsp = 0;
818 struct pt_regs *regs = tsk->thread.regs;
819 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
820 /* Save the thread's msr before get_tm_stackpointer() changes it */
821 unsigned long msr = regs->msr;
824 BUG_ON(tsk != current);
826 frame = get_sigframe(ksig, get_tm_stackpointer(tsk), sizeof(*frame), 0);
827 if (unlikely(frame == NULL))
830 err |= __put_user(&frame->info, &frame->pinfo);
831 err |= __put_user(&frame->uc, &frame->puc);
832 err |= copy_siginfo_to_user(&frame->info, &ksig->info);
836 /* Create the ucontext. */
837 err |= __put_user(0, &frame->uc.uc_flags);
838 err |= __save_altstack(&frame->uc.uc_stack, regs->gpr[1]);
839 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
840 if (MSR_TM_ACTIVE(msr)) {
841 /* The ucontext_t passed to userland points to the second
842 * ucontext_t (for transactional state) with its uc_link ptr.
844 err |= __put_user(&frame->uc_transact, &frame->uc.uc_link);
845 err |= setup_tm_sigcontexts(&frame->uc.uc_mcontext,
846 &frame->uc_transact.uc_mcontext,
847 tsk, ksig->sig, NULL,
848 (unsigned long)ksig->ka.sa.sa_handler,
853 err |= __put_user(0, &frame->uc.uc_link);
854 err |= setup_sigcontext(&frame->uc.uc_mcontext, tsk, ksig->sig,
855 NULL, (unsigned long)ksig->ka.sa.sa_handler,
858 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
862 /* Make sure signal handler doesn't get spurious FP exceptions */
863 tsk->thread.fp_state.fpscr = 0;
865 /* Set up to return from userspace. */
866 if (vdso64_rt_sigtramp && tsk->mm->context.vdso_base) {
867 regs->link = tsk->mm->context.vdso_base + vdso64_rt_sigtramp;
869 err |= setup_trampoline(__NR_rt_sigreturn, &frame->tramp[0]);
872 regs->link = (unsigned long) &frame->tramp[0];
875 /* Allocate a dummy caller frame for the signal handler. */
876 newsp = ((unsigned long)frame) - __SIGNAL_FRAMESIZE;
877 err |= put_user(regs->gpr[1], (unsigned long __user *)newsp);
879 /* Set up "regs" so we "return" to the signal handler. */
880 if (is_elf2_task()) {
881 regs->nip = (unsigned long) ksig->ka.sa.sa_handler;
882 regs->gpr[12] = regs->nip;
884 /* Handler is *really* a pointer to the function descriptor for
885 * the signal routine. The first entry in the function
886 * descriptor is the entry address of signal and the second
887 * entry is the TOC value we need to use.
889 func_descr_t __user *funct_desc_ptr =
890 (func_descr_t __user *) ksig->ka.sa.sa_handler;
892 err |= get_user(regs->nip, &funct_desc_ptr->entry);
893 err |= get_user(regs->gpr[2], &funct_desc_ptr->toc);
896 /* enter the signal handler in native-endian mode */
897 regs->msr &= ~MSR_LE;
898 regs->msr |= (MSR_KERNEL & MSR_LE);
899 regs->gpr[1] = newsp;
900 regs->gpr[3] = ksig->sig;
902 if (ksig->ka.sa.sa_flags & SA_SIGINFO) {
903 err |= get_user(regs->gpr[4], (unsigned long __user *)&frame->pinfo);
904 err |= get_user(regs->gpr[5], (unsigned long __user *)&frame->puc);
905 regs->gpr[6] = (unsigned long) frame;
907 regs->gpr[4] = (unsigned long)&frame->uc.uc_mcontext;
915 if (show_unhandled_signals)
916 printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32,
917 tsk->comm, tsk->pid, "setup_rt_frame",
918 (long)frame, regs->nip, regs->link);