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/pgtable.h>
29 #include <asm/unistd.h>
30 #include <asm/cacheflush.h>
31 #include <asm/syscalls.h>
33 #include <asm/switch_to.h>
35 #include <asm/asm-prototypes.h>
40 #define GP_REGS_SIZE min(sizeof(elf_gregset_t), sizeof(struct pt_regs))
41 #define FP_REGS_SIZE sizeof(elf_fpregset_t)
43 #define TRAMP_TRACEBACK 3
47 * When we have signals to deliver, we set up on the user stack,
48 * going down from the original stack pointer:
49 * 1) a rt_sigframe struct which contains the ucontext
50 * 2) a gap of __SIGNAL_FRAMESIZE bytes which acts as a dummy caller
51 * frame for the signal handler.
55 /* sys_rt_sigreturn requires the ucontext be the first field */
57 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
58 struct ucontext uc_transact;
60 unsigned long _unused[2];
61 unsigned int tramp[TRAMP_SIZE];
62 struct siginfo __user *pinfo;
65 /* New 64 bit little-endian ABI allows redzone of 512 bytes below sp */
66 char abigap[USER_REDZONE_SIZE];
67 } __attribute__ ((aligned (16)));
69 static const char fmt32[] = KERN_INFO \
70 "%s[%d]: bad frame in %s: %08lx nip %08lx lr %08lx\n";
71 static const char fmt64[] = KERN_INFO \
72 "%s[%d]: bad frame in %s: %016lx nip %016lx lr %016lx\n";
75 * This computes a quad word aligned pointer inside the vmx_reserve array
76 * element. For historical reasons sigcontext might not be quad word aligned,
77 * but the location we write the VMX regs to must be. See the comment in
78 * sigcontext for more detail.
81 static elf_vrreg_t __user *sigcontext_vmx_regs(struct sigcontext __user *sc)
83 return (elf_vrreg_t __user *) (((unsigned long)sc->vmx_reserve + 15) & ~0xful);
88 * Set up the sigcontext for the signal frame.
91 static long setup_sigcontext(struct sigcontext __user *sc,
92 struct task_struct *tsk, int signr, sigset_t *set,
93 unsigned long handler, int ctx_has_vsx_region)
95 /* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the
96 * process never used altivec yet (MSR_VEC is zero in pt_regs of
97 * the context). This is very important because we must ensure we
98 * don't lose the VRSAVE content that may have been set prior to
99 * the process doing its first vector operation
100 * Userland shall check AT_HWCAP to know whether it can rely on the
101 * v_regs pointer or not
103 #ifdef CONFIG_ALTIVEC
104 elf_vrreg_t __user *v_regs = sigcontext_vmx_regs(sc);
105 unsigned long vrsave;
107 struct pt_regs *regs = tsk->thread.regs;
108 unsigned long msr = regs->msr;
110 /* Force usr to alway see softe as 1 (interrupts enabled) */
111 unsigned long softe = 0x1;
113 BUG_ON(tsk != current);
115 #ifdef CONFIG_ALTIVEC
116 err |= __put_user(v_regs, &sc->v_regs);
118 /* save altivec registers */
119 if (tsk->thread.used_vr) {
120 flush_altivec_to_thread(tsk);
121 /* Copy 33 vec registers (vr0..31 and vscr) to the stack */
122 err |= __copy_to_user(v_regs, &tsk->thread.vr_state,
123 33 * sizeof(vector128));
124 /* set MSR_VEC in the MSR value in the frame to indicate that sc->v_reg)
125 * contains valid data.
129 /* We always copy to/from vrsave, it's 0 if we don't have or don't
133 if (cpu_has_feature(CPU_FTR_ALTIVEC)) {
134 vrsave = mfspr(SPRN_VRSAVE);
135 tsk->thread.vrsave = vrsave;
138 err |= __put_user(vrsave, (u32 __user *)&v_regs[33]);
139 #else /* CONFIG_ALTIVEC */
140 err |= __put_user(0, &sc->v_regs);
141 #endif /* CONFIG_ALTIVEC */
142 flush_fp_to_thread(tsk);
143 /* copy fpr regs and fpscr */
144 err |= copy_fpr_to_user(&sc->fp_regs, tsk);
147 * Clear the MSR VSX bit to indicate there is no valid state attached
148 * to this context, except in the specific case below where we set it.
153 * Copy VSX low doubleword to local buffer for formatting,
154 * then out to userspace. Update v_regs to point after the
157 if (tsk->thread.used_vsr && ctx_has_vsx_region) {
158 flush_vsx_to_thread(tsk);
159 v_regs += ELF_NVRREG;
160 err |= copy_vsx_to_user(v_regs, tsk);
161 /* set MSR_VSX in the MSR value in the frame to
162 * indicate that sc->vs_reg) contains valid data.
166 #endif /* CONFIG_VSX */
167 err |= __put_user(&sc->gp_regs, &sc->regs);
168 WARN_ON(!FULL_REGS(regs));
169 err |= __copy_to_user(&sc->gp_regs, regs, GP_REGS_SIZE);
170 err |= __put_user(msr, &sc->gp_regs[PT_MSR]);
171 err |= __put_user(softe, &sc->gp_regs[PT_SOFTE]);
172 err |= __put_user(signr, &sc->signal);
173 err |= __put_user(handler, &sc->handler);
175 err |= __put_user(set->sig[0], &sc->oldmask);
180 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
182 * As above, but Transactional Memory is in use, so deliver sigcontexts
183 * containing checkpointed and transactional register states.
185 * To do this, we treclaim (done before entering here) to gather both sets of
186 * registers and set up the 'normal' sigcontext registers with rolled-back
187 * register values such that a simple signal handler sees a correct
188 * checkpointed register state. If interested, a TM-aware sighandler can
189 * examine the transactional registers in the 2nd sigcontext to determine the
190 * real origin of the signal.
192 static long setup_tm_sigcontexts(struct sigcontext __user *sc,
193 struct sigcontext __user *tm_sc,
194 struct task_struct *tsk,
195 int signr, sigset_t *set, unsigned long handler,
198 /* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the
199 * process never used altivec yet (MSR_VEC is zero in pt_regs of
200 * the context). This is very important because we must ensure we
201 * don't lose the VRSAVE content that may have been set prior to
202 * the process doing its first vector operation
203 * Userland shall check AT_HWCAP to know wether it can rely on the
204 * v_regs pointer or not.
206 #ifdef CONFIG_ALTIVEC
207 elf_vrreg_t __user *v_regs = sigcontext_vmx_regs(sc);
208 elf_vrreg_t __user *tm_v_regs = sigcontext_vmx_regs(tm_sc);
210 struct pt_regs *regs = tsk->thread.regs;
213 BUG_ON(tsk != current);
215 BUG_ON(!MSR_TM_ACTIVE(msr));
217 WARN_ON(tm_suspend_disabled);
219 /* Restore checkpointed FP, VEC, and VSX bits from ckpt_regs as
220 * it contains the correct FP, VEC, VSX state after we treclaimed
221 * the transaction and giveup_all() was called on reclaiming.
223 msr |= tsk->thread.ckpt_regs.msr & (MSR_FP | MSR_VEC | MSR_VSX);
225 #ifdef CONFIG_ALTIVEC
226 err |= __put_user(v_regs, &sc->v_regs);
227 err |= __put_user(tm_v_regs, &tm_sc->v_regs);
229 /* save altivec registers */
230 if (tsk->thread.used_vr) {
231 /* Copy 33 vec registers (vr0..31 and vscr) to the stack */
232 err |= __copy_to_user(v_regs, &tsk->thread.ckvr_state,
233 33 * sizeof(vector128));
234 /* If VEC was enabled there are transactional VRs valid too,
235 * else they're a copy of the checkpointed VRs.
238 err |= __copy_to_user(tm_v_regs,
239 &tsk->thread.vr_state,
240 33 * sizeof(vector128));
242 err |= __copy_to_user(tm_v_regs,
243 &tsk->thread.ckvr_state,
244 33 * sizeof(vector128));
246 /* set MSR_VEC in the MSR value in the frame to indicate
247 * that sc->v_reg contains valid data.
251 /* We always copy to/from vrsave, it's 0 if we don't have or don't
254 if (cpu_has_feature(CPU_FTR_ALTIVEC))
255 tsk->thread.ckvrsave = mfspr(SPRN_VRSAVE);
256 err |= __put_user(tsk->thread.ckvrsave, (u32 __user *)&v_regs[33]);
258 err |= __put_user(tsk->thread.vrsave,
259 (u32 __user *)&tm_v_regs[33]);
261 err |= __put_user(tsk->thread.ckvrsave,
262 (u32 __user *)&tm_v_regs[33]);
264 #else /* CONFIG_ALTIVEC */
265 err |= __put_user(0, &sc->v_regs);
266 err |= __put_user(0, &tm_sc->v_regs);
267 #endif /* CONFIG_ALTIVEC */
269 /* copy fpr regs and fpscr */
270 err |= copy_ckfpr_to_user(&sc->fp_regs, tsk);
272 err |= copy_fpr_to_user(&tm_sc->fp_regs, tsk);
274 err |= copy_ckfpr_to_user(&tm_sc->fp_regs, tsk);
278 * Copy VSX low doubleword to local buffer for formatting,
279 * then out to userspace. Update v_regs to point after the
282 if (tsk->thread.used_vsr) {
283 v_regs += ELF_NVRREG;
284 tm_v_regs += ELF_NVRREG;
286 err |= copy_ckvsx_to_user(v_regs, tsk);
289 err |= copy_vsx_to_user(tm_v_regs, tsk);
291 err |= copy_ckvsx_to_user(tm_v_regs, tsk);
293 /* set MSR_VSX in the MSR value in the frame to
294 * indicate that sc->vs_reg) contains valid data.
298 #endif /* CONFIG_VSX */
300 err |= __put_user(&sc->gp_regs, &sc->regs);
301 err |= __put_user(&tm_sc->gp_regs, &tm_sc->regs);
302 WARN_ON(!FULL_REGS(regs));
303 err |= __copy_to_user(&tm_sc->gp_regs, regs, GP_REGS_SIZE);
304 err |= __copy_to_user(&sc->gp_regs,
305 &tsk->thread.ckpt_regs, GP_REGS_SIZE);
306 err |= __put_user(msr, &tm_sc->gp_regs[PT_MSR]);
307 err |= __put_user(msr, &sc->gp_regs[PT_MSR]);
308 err |= __put_user(signr, &sc->signal);
309 err |= __put_user(handler, &sc->handler);
311 err |= __put_user(set->sig[0], &sc->oldmask);
318 * Restore the sigcontext from the signal frame.
321 static long restore_sigcontext(struct task_struct *tsk, sigset_t *set, int sig,
322 struct sigcontext __user *sc)
324 #ifdef CONFIG_ALTIVEC
325 elf_vrreg_t __user *v_regs;
327 unsigned long err = 0;
328 unsigned long save_r13 = 0;
330 struct pt_regs *regs = tsk->thread.regs;
335 BUG_ON(tsk != current);
337 /* If this is not a signal return, we preserve the TLS in r13 */
339 save_r13 = regs->gpr[13];
342 err |= __copy_from_user(regs->gpr, sc->gp_regs, sizeof(regs->gpr));
343 err |= __get_user(regs->nip, &sc->gp_regs[PT_NIP]);
344 /* get MSR separately, transfer the LE bit if doing signal return */
345 err |= __get_user(msr, &sc->gp_regs[PT_MSR]);
347 regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE);
348 err |= __get_user(regs->orig_gpr3, &sc->gp_regs[PT_ORIG_R3]);
349 err |= __get_user(regs->ctr, &sc->gp_regs[PT_CTR]);
350 err |= __get_user(regs->link, &sc->gp_regs[PT_LNK]);
351 err |= __get_user(regs->xer, &sc->gp_regs[PT_XER]);
352 err |= __get_user(regs->ccr, &sc->gp_regs[PT_CCR]);
355 err |= __get_user(regs->dar, &sc->gp_regs[PT_DAR]);
356 err |= __get_user(regs->dsisr, &sc->gp_regs[PT_DSISR]);
357 err |= __get_user(regs->result, &sc->gp_regs[PT_RESULT]);
360 regs->gpr[13] = save_r13;
362 err |= __get_user(set->sig[0], &sc->oldmask);
365 * Force reload of FP/VEC.
366 * This has to be done before copying stuff into tsk->thread.fpr/vr
367 * for the reasons explained in the previous comment.
369 regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC | MSR_VSX);
371 #ifdef CONFIG_ALTIVEC
372 err |= __get_user(v_regs, &sc->v_regs);
375 if (v_regs && !access_ok(v_regs, 34 * sizeof(vector128)))
377 /* Copy 33 vec registers (vr0..31 and vscr) from the stack */
378 if (v_regs != NULL && (msr & MSR_VEC) != 0) {
379 err |= __copy_from_user(&tsk->thread.vr_state, v_regs,
380 33 * sizeof(vector128));
381 tsk->thread.used_vr = true;
382 } else if (tsk->thread.used_vr) {
383 memset(&tsk->thread.vr_state, 0, 33 * sizeof(vector128));
385 /* Always get VRSAVE back */
387 err |= __get_user(tsk->thread.vrsave, (u32 __user *)&v_regs[33]);
389 tsk->thread.vrsave = 0;
390 if (cpu_has_feature(CPU_FTR_ALTIVEC))
391 mtspr(SPRN_VRSAVE, tsk->thread.vrsave);
392 #endif /* CONFIG_ALTIVEC */
393 /* restore floating point */
394 err |= copy_fpr_from_user(tsk, &sc->fp_regs);
397 * Get additional VSX data. Update v_regs to point after the
398 * VMX data. Copy VSX low doubleword from userspace to local
399 * buffer for formatting, then into the taskstruct.
401 v_regs += ELF_NVRREG;
402 if ((msr & MSR_VSX) != 0) {
403 err |= copy_vsx_from_user(tsk, v_regs);
404 tsk->thread.used_vsr = true;
406 for (i = 0; i < 32 ; i++)
407 tsk->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
413 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
415 * Restore the two sigcontexts from the frame of a transactional processes.
418 static long restore_tm_sigcontexts(struct task_struct *tsk,
419 struct sigcontext __user *sc,
420 struct sigcontext __user *tm_sc)
422 #ifdef CONFIG_ALTIVEC
423 elf_vrreg_t __user *v_regs, *tm_v_regs;
425 unsigned long err = 0;
427 struct pt_regs *regs = tsk->thread.regs;
432 BUG_ON(tsk != current);
434 if (tm_suspend_disabled)
438 err |= __copy_from_user(regs->gpr, tm_sc->gp_regs, sizeof(regs->gpr));
439 err |= __copy_from_user(&tsk->thread.ckpt_regs, sc->gp_regs,
443 * TFHAR is restored from the checkpointed 'wound-back' ucontext's NIP.
444 * TEXASR was set by the signal delivery reclaim, as was TFIAR.
445 * Users doing anything abhorrent like thread-switching w/ signals for
446 * TM-Suspended code will have to back TEXASR/TFIAR up themselves.
447 * For the case of getting a signal and simply returning from it,
448 * we don't need to re-copy them here.
450 err |= __get_user(regs->nip, &tm_sc->gp_regs[PT_NIP]);
451 err |= __get_user(tsk->thread.tm_tfhar, &sc->gp_regs[PT_NIP]);
453 /* get MSR separately, transfer the LE bit if doing signal return */
454 err |= __get_user(msr, &sc->gp_regs[PT_MSR]);
455 /* Don't allow reserved mode. */
456 if (MSR_TM_RESV(msr))
459 /* pull in MSR LE from user context */
460 regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE);
462 /* The following non-GPR non-FPR non-VR state is also checkpointed: */
463 err |= __get_user(regs->ctr, &tm_sc->gp_regs[PT_CTR]);
464 err |= __get_user(regs->link, &tm_sc->gp_regs[PT_LNK]);
465 err |= __get_user(regs->xer, &tm_sc->gp_regs[PT_XER]);
466 err |= __get_user(regs->ccr, &tm_sc->gp_regs[PT_CCR]);
467 err |= __get_user(tsk->thread.ckpt_regs.ctr,
468 &sc->gp_regs[PT_CTR]);
469 err |= __get_user(tsk->thread.ckpt_regs.link,
470 &sc->gp_regs[PT_LNK]);
471 err |= __get_user(tsk->thread.ckpt_regs.xer,
472 &sc->gp_regs[PT_XER]);
473 err |= __get_user(tsk->thread.ckpt_regs.ccr,
474 &sc->gp_regs[PT_CCR]);
476 /* Don't allow userspace to set the trap value */
479 /* These regs are not checkpointed; they can go in 'regs'. */
480 err |= __get_user(regs->dar, &sc->gp_regs[PT_DAR]);
481 err |= __get_user(regs->dsisr, &sc->gp_regs[PT_DSISR]);
482 err |= __get_user(regs->result, &sc->gp_regs[PT_RESULT]);
485 * Force reload of FP/VEC.
486 * This has to be done before copying stuff into tsk->thread.fpr/vr
487 * for the reasons explained in the previous comment.
489 regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC | MSR_VSX);
491 #ifdef CONFIG_ALTIVEC
492 err |= __get_user(v_regs, &sc->v_regs);
493 err |= __get_user(tm_v_regs, &tm_sc->v_regs);
496 if (v_regs && !access_ok(v_regs, 34 * sizeof(vector128)))
498 if (tm_v_regs && !access_ok(tm_v_regs, 34 * sizeof(vector128)))
500 /* Copy 33 vec registers (vr0..31 and vscr) from the stack */
501 if (v_regs != NULL && tm_v_regs != NULL && (msr & MSR_VEC) != 0) {
502 err |= __copy_from_user(&tsk->thread.ckvr_state, v_regs,
503 33 * sizeof(vector128));
504 err |= __copy_from_user(&tsk->thread.vr_state, tm_v_regs,
505 33 * sizeof(vector128));
506 current->thread.used_vr = true;
508 else if (tsk->thread.used_vr) {
509 memset(&tsk->thread.vr_state, 0, 33 * sizeof(vector128));
510 memset(&tsk->thread.ckvr_state, 0, 33 * sizeof(vector128));
512 /* Always get VRSAVE back */
513 if (v_regs != NULL && tm_v_regs != NULL) {
514 err |= __get_user(tsk->thread.ckvrsave,
515 (u32 __user *)&v_regs[33]);
516 err |= __get_user(tsk->thread.vrsave,
517 (u32 __user *)&tm_v_regs[33]);
520 tsk->thread.vrsave = 0;
521 tsk->thread.ckvrsave = 0;
523 if (cpu_has_feature(CPU_FTR_ALTIVEC))
524 mtspr(SPRN_VRSAVE, tsk->thread.vrsave);
525 #endif /* CONFIG_ALTIVEC */
526 /* restore floating point */
527 err |= copy_fpr_from_user(tsk, &tm_sc->fp_regs);
528 err |= copy_ckfpr_from_user(tsk, &sc->fp_regs);
531 * Get additional VSX data. Update v_regs to point after the
532 * VMX data. Copy VSX low doubleword from userspace to local
533 * buffer for formatting, then into the taskstruct.
535 if (v_regs && ((msr & MSR_VSX) != 0)) {
536 v_regs += ELF_NVRREG;
537 tm_v_regs += ELF_NVRREG;
538 err |= copy_vsx_from_user(tsk, tm_v_regs);
539 err |= copy_ckvsx_from_user(tsk, v_regs);
540 tsk->thread.used_vsr = true;
542 for (i = 0; i < 32 ; i++) {
543 tsk->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
544 tsk->thread.ckfp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
549 /* Make sure the transaction is marked as failed */
550 tsk->thread.tm_texasr |= TEXASR_FS;
553 * Disabling preemption, since it is unsafe to be preempted
554 * with MSR[TS] set without recheckpointing.
558 /* pull in MSR TS bits from user context */
559 regs->msr |= msr & MSR_TS_MASK;
562 * Ensure that TM is enabled in regs->msr before we leave the signal
563 * handler. It could be the case that (a) user disabled the TM bit
564 * through the manipulation of the MSR bits in uc_mcontext or (b) the
565 * TM bit was disabled because a sufficient number of context switches
566 * happened whilst in the signal handler and load_tm overflowed,
567 * disabling the TM bit. In either case we can end up with an illegal
568 * TM state leading to a TM Bad Thing when we return to userspace.
571 * After regs->MSR[TS] being updated, make sure that get_user(),
572 * put_user() or similar functions are *not* called. These
573 * functions can generate page faults which will cause the process
574 * to be de-scheduled with MSR[TS] set but without calling
575 * tm_recheckpoint(). This can cause a bug.
579 /* This loads the checkpointed FP/VEC state, if used */
580 tm_recheckpoint(&tsk->thread);
582 msr_check_and_set(msr & (MSR_FP | MSR_VEC));
584 load_fp_state(&tsk->thread.fp_state);
585 regs->msr |= (MSR_FP | tsk->thread.fpexc_mode);
588 load_vr_state(&tsk->thread.vr_state);
589 regs->msr |= MSR_VEC;
599 * Setup the trampoline code on the stack
601 static long setup_trampoline(unsigned int syscall, unsigned int __user *tramp)
606 /* addi r1, r1, __SIGNAL_FRAMESIZE # Pop the dummy stackframe */
607 err |= __put_user(PPC_INST_ADDI | __PPC_RT(R1) | __PPC_RA(R1) |
608 (__SIGNAL_FRAMESIZE & 0xffff), &tramp[0]);
609 /* li r0, __NR_[rt_]sigreturn| */
610 err |= __put_user(PPC_INST_ADDI | (syscall & 0xffff), &tramp[1]);
612 err |= __put_user(PPC_INST_SC, &tramp[2]);
614 /* Minimal traceback info */
615 for (i=TRAMP_TRACEBACK; i < TRAMP_SIZE ;i++)
616 err |= __put_user(0, &tramp[i]);
619 flush_icache_range((unsigned long) &tramp[0],
620 (unsigned long) &tramp[TRAMP_SIZE]);
626 * Userspace code may pass a ucontext which doesn't include VSX added
627 * at the end. We need to check for this case.
629 #define UCONTEXTSIZEWITHOUTVSX \
630 (sizeof(struct ucontext) - 32*sizeof(long))
633 * Handle {get,set,swap}_context operations
635 SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx,
636 struct ucontext __user *, new_ctx, long, ctx_size)
640 unsigned long new_msr = 0;
641 int ctx_has_vsx_region = 0;
644 get_user(new_msr, &new_ctx->uc_mcontext.gp_regs[PT_MSR]))
647 * Check that the context is not smaller than the original
648 * size (with VMX but without VSX)
650 if (ctx_size < UCONTEXTSIZEWITHOUTVSX)
653 * If the new context state sets the MSR VSX bits but
654 * it doesn't provide VSX state.
656 if ((ctx_size < sizeof(struct ucontext)) &&
659 /* Does the context have enough room to store VSX data? */
660 if (ctx_size >= sizeof(struct ucontext))
661 ctx_has_vsx_region = 1;
663 if (old_ctx != NULL) {
664 if (!access_ok(old_ctx, ctx_size)
665 || setup_sigcontext(&old_ctx->uc_mcontext, current, 0, NULL, 0,
667 || __copy_to_user(&old_ctx->uc_sigmask,
668 ¤t->blocked, sizeof(sigset_t)))
673 if (!access_ok(new_ctx, ctx_size)
674 || __get_user(tmp, (u8 __user *) new_ctx)
675 || __get_user(tmp, (u8 __user *) new_ctx + ctx_size - 1))
679 * If we get a fault copying the context into the kernel's
680 * image of the user's registers, we can't just return -EFAULT
681 * because the user's registers will be corrupted. For instance
682 * the NIP value may have been updated but not some of the
683 * other registers. Given that we have done the access_ok
684 * and successfully read the first and last bytes of the region
685 * above, this should only happen in an out-of-memory situation
686 * or if another thread unmaps the region containing the context.
687 * We kill the task with a SIGSEGV in this situation.
690 if (__copy_from_user(&set, &new_ctx->uc_sigmask, sizeof(set)))
692 set_current_blocked(&set);
693 if (restore_sigcontext(current, NULL, 0, &new_ctx->uc_mcontext))
696 /* This returns like rt_sigreturn */
697 set_thread_flag(TIF_RESTOREALL);
703 * Do a signal return; undo the signal stack.
706 SYSCALL_DEFINE0(rt_sigreturn)
708 struct pt_regs *regs = current_pt_regs();
709 struct ucontext __user *uc = (struct ucontext __user *)regs->gpr[1];
711 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
715 /* Always make any pending restarted system calls return -EINTR */
716 current->restart_block.fn = do_no_restart_syscall;
718 if (!access_ok(uc, sizeof(*uc)))
721 if (__copy_from_user(&set, &uc->uc_sigmask, sizeof(set)))
723 set_current_blocked(&set);
725 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
727 * If there is a transactional state then throw it away.
728 * The purpose of a sigreturn is to destroy all traces of the
729 * signal frame, this includes any transactional state created
730 * within in. We only check for suspended as we can never be
731 * active in the kernel, we are active, there is nothing better to
732 * do than go ahead and Bad Thing later.
733 * The cause is not important as there will never be a
734 * recheckpoint so it's not user visible.
736 if (MSR_TM_SUSPENDED(mfmsr()))
737 tm_reclaim_current(0);
740 * Disable MSR[TS] bit also, so, if there is an exception in the
741 * code below (as a page fault in copy_ckvsx_to_user()), it does
742 * not recheckpoint this task if there was a context switch inside
745 * A major page fault can indirectly call schedule(). A reschedule
746 * process in the middle of an exception can have a side effect
747 * (Changing the CPU MSR[TS] state), since schedule() is called
748 * with the CPU MSR[TS] disable and returns with MSR[TS]=Suspended
749 * (switch_to() calls tm_recheckpoint() for the 'new' process). In
750 * this case, the process continues to be the same in the CPU, but
751 * the CPU state just changed.
753 * This can cause a TM Bad Thing, since the MSR in the stack will
754 * have the MSR[TS]=0, and this is what will be used to RFID.
756 * Clearing MSR[TS] state here will avoid a recheckpoint if there
757 * is any process reschedule in kernel space. The MSR[TS] state
758 * does not need to be saved also, since it will be replaced with
759 * the MSR[TS] that came from user context later, at
760 * restore_tm_sigcontexts.
762 regs->msr &= ~MSR_TS_MASK;
764 if (__get_user(msr, &uc->uc_mcontext.gp_regs[PT_MSR]))
766 if (MSR_TM_ACTIVE(msr)) {
767 /* We recheckpoint on return. */
768 struct ucontext __user *uc_transact;
770 /* Trying to start TM on non TM system */
771 if (!cpu_has_feature(CPU_FTR_TM))
774 if (__get_user(uc_transact, &uc->uc_link))
776 if (restore_tm_sigcontexts(current, &uc->uc_mcontext,
777 &uc_transact->uc_mcontext))
783 * Fall through, for non-TM restore
785 * Unset MSR[TS] on the thread regs since MSR from user
786 * context does not have MSR active, and recheckpoint was
787 * not called since restore_tm_sigcontexts() was not called
790 * If not unsetting it, the code can RFID to userspace with
791 * MSR[TS] set, but without CPU in the proper state,
792 * causing a TM bad thing.
794 current->thread.regs->msr &= ~MSR_TS_MASK;
795 if (restore_sigcontext(current, NULL, 1, &uc->uc_mcontext))
799 if (restore_altstack(&uc->uc_stack))
802 set_thread_flag(TIF_RESTOREALL);
806 if (show_unhandled_signals)
807 printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32,
808 current->comm, current->pid, "rt_sigreturn",
809 (long)uc, regs->nip, regs->link);
815 int handle_rt_signal64(struct ksignal *ksig, sigset_t *set,
816 struct task_struct *tsk)
818 struct rt_sigframe __user *frame;
819 unsigned long newsp = 0;
821 struct pt_regs *regs = tsk->thread.regs;
822 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
823 /* Save the thread's msr before get_tm_stackpointer() changes it */
824 unsigned long msr = regs->msr;
827 BUG_ON(tsk != current);
829 frame = get_sigframe(ksig, get_tm_stackpointer(tsk), sizeof(*frame), 0);
830 if (unlikely(frame == NULL))
833 err |= __put_user(&frame->info, &frame->pinfo);
834 err |= __put_user(&frame->uc, &frame->puc);
835 err |= copy_siginfo_to_user(&frame->info, &ksig->info);
839 /* Create the ucontext. */
840 err |= __put_user(0, &frame->uc.uc_flags);
841 err |= __save_altstack(&frame->uc.uc_stack, regs->gpr[1]);
842 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
843 if (MSR_TM_ACTIVE(msr)) {
844 /* The ucontext_t passed to userland points to the second
845 * ucontext_t (for transactional state) with its uc_link ptr.
847 err |= __put_user(&frame->uc_transact, &frame->uc.uc_link);
848 err |= setup_tm_sigcontexts(&frame->uc.uc_mcontext,
849 &frame->uc_transact.uc_mcontext,
850 tsk, ksig->sig, NULL,
851 (unsigned long)ksig->ka.sa.sa_handler,
856 err |= __put_user(0, &frame->uc.uc_link);
857 err |= setup_sigcontext(&frame->uc.uc_mcontext, tsk, ksig->sig,
858 NULL, (unsigned long)ksig->ka.sa.sa_handler,
861 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
865 /* Make sure signal handler doesn't get spurious FP exceptions */
866 tsk->thread.fp_state.fpscr = 0;
868 /* Set up to return from userspace. */
869 if (vdso64_rt_sigtramp && tsk->mm->context.vdso_base) {
870 regs->link = tsk->mm->context.vdso_base + vdso64_rt_sigtramp;
872 err |= setup_trampoline(__NR_rt_sigreturn, &frame->tramp[0]);
875 regs->link = (unsigned long) &frame->tramp[0];
878 /* Allocate a dummy caller frame for the signal handler. */
879 newsp = ((unsigned long)frame) - __SIGNAL_FRAMESIZE;
880 err |= put_user(regs->gpr[1], (unsigned long __user *)newsp);
882 /* Set up "regs" so we "return" to the signal handler. */
883 if (is_elf2_task()) {
884 regs->nip = (unsigned long) ksig->ka.sa.sa_handler;
885 regs->gpr[12] = regs->nip;
887 /* Handler is *really* a pointer to the function descriptor for
888 * the signal routine. The first entry in the function
889 * descriptor is the entry address of signal and the second
890 * entry is the TOC value we need to use.
892 func_descr_t __user *funct_desc_ptr =
893 (func_descr_t __user *) ksig->ka.sa.sa_handler;
895 err |= get_user(regs->nip, &funct_desc_ptr->entry);
896 err |= get_user(regs->gpr[2], &funct_desc_ptr->toc);
899 /* enter the signal handler in native-endian mode */
900 regs->msr &= ~MSR_LE;
901 regs->msr |= (MSR_KERNEL & MSR_LE);
902 regs->gpr[1] = newsp;
903 regs->gpr[3] = ksig->sig;
905 if (ksig->ka.sa.sa_flags & SA_SIGINFO) {
906 err |= get_user(regs->gpr[4], (unsigned long __user *)&frame->pinfo);
907 err |= get_user(regs->gpr[5], (unsigned long __user *)&frame->puc);
908 regs->gpr[6] = (unsigned long) frame;
910 regs->gpr[4] = (unsigned long)&frame->uc.uc_mcontext;
918 if (show_unhandled_signals)
919 printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32,
920 tsk->comm, tsk->pid, "setup_rt_frame",
921 (long)frame, regs->nip, regs->link);