static long restore_tm_sigcontexts(struct pt_regs *regs,
				   struct sigcontext __user *sc,
				   struct sigcontext __user *tm_sc)
{
#ifdef CONFIG_ALTIVEC
	elf_vrreg_t __user *v_regs, *tm_v_regs;
#endif
	unsigned long err = 0;
	unsigned long msr;
#ifdef CONFIG_VSX
	int i;
#endif
	/* copy the GPRs */
	err |= __copy_from_user(regs->gpr, tm_sc->gp_regs, sizeof(regs->gpr));
	err |= __copy_from_user(&current->thread.ckpt_regs, sc->gp_regs,
				sizeof(regs->gpr));

	/*
	 * TFHAR is restored from the checkpointed 'wound-back' ucontext's NIP.
	 * TEXASR was set by the signal delivery reclaim, as was TFIAR.
	 * Users doing anything abhorrent like thread-switching w/ signals for
	 * TM-Suspended code will have to back TEXASR/TFIAR up themselves.
	 * For the case of getting a signal and simply returning from it,
	 * we don't need to re-copy them here.
	 */
	err |= __get_user(regs->nip, &tm_sc->gp_regs[PT_NIP]);
	err |= __get_user(current->thread.tm_tfhar, &sc->gp_regs[PT_NIP]);

	/* get MSR separately, transfer the LE bit if doing signal return */
	err |= __get_user(msr, &sc->gp_regs[PT_MSR]);
	/* Don't allow reserved mode. */
	if (MSR_TM_RESV(msr))
		return -EINVAL;

	/* pull in MSR TM from user context */
	regs->msr = (regs->msr & ~MSR_TS_MASK) | (msr & MSR_TS_MASK);

	/* pull in MSR LE from user context */
	regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE);

	/* The following non-GPR non-FPR non-VR state is also checkpointed: */
	err |= __get_user(regs->ctr, &tm_sc->gp_regs[PT_CTR]);
	err |= __get_user(regs->link, &tm_sc->gp_regs[PT_LNK]);
	err |= __get_user(regs->xer, &tm_sc->gp_regs[PT_XER]);
	err |= __get_user(regs->ccr, &tm_sc->gp_regs[PT_CCR]);
	err |= __get_user(current->thread.ckpt_regs.ctr,
			  &sc->gp_regs[PT_CTR]);
	err |= __get_user(current->thread.ckpt_regs.link,
			  &sc->gp_regs[PT_LNK]);
	err |= __get_user(current->thread.ckpt_regs.xer,
			  &sc->gp_regs[PT_XER]);
	err |= __get_user(current->thread.ckpt_regs.ccr,
			  &sc->gp_regs[PT_CCR]);

	/* These regs are not checkpointed; they can go in 'regs'. */
	err |= __get_user(regs->trap, &sc->gp_regs[PT_TRAP]);
	err |= __get_user(regs->dar, &sc->gp_regs[PT_DAR]);
	err |= __get_user(regs->dsisr, &sc->gp_regs[PT_DSISR]);
	err |= __get_user(regs->result, &sc->gp_regs[PT_RESULT]);

	/*
	 * Do this before updating the thread state in
	 * current->thread.fpr/vr.  That way, if we get preempted
	 * and another task grabs the FPU/Altivec, it won't be
	 * tempted to save the current CPU state into the thread_struct
	 * and corrupt what we are writing there.
	 */
	discard_lazy_cpu_state();

	/*
	 * Force reload of FP/VEC.
	 * This has to be done before copying stuff into current->thread.fpr/vr
	 * for the reasons explained in the previous comment.
	 */
	regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC | MSR_VSX);

#ifdef CONFIG_ALTIVEC
	err |= __get_user(v_regs, &sc->v_regs);
	err |= __get_user(tm_v_regs, &tm_sc->v_regs);
	if (err)
		return err;
	if (v_regs && !access_ok(VERIFY_READ, v_regs, 34 * sizeof(vector128)))
		return -EFAULT;
	if (tm_v_regs && !access_ok(VERIFY_READ,
				    tm_v_regs, 34 * sizeof(vector128)))
		return -EFAULT;
	/* Copy 33 vec registers (vr0..31 and vscr) from the stack */
	if (v_regs != NULL && tm_v_regs != NULL && (msr & MSR_VEC) != 0) {
		err |= __copy_from_user(&current->thread.vr_state, v_regs,
					33 * sizeof(vector128));
		err |= __copy_from_user(&current->thread.transact_vr, tm_v_regs,
					33 * sizeof(vector128));
	}
	else if (current->thread.used_vr) {
		memset(&current->thread.vr_state, 0, 33 * sizeof(vector128));
		memset(&current->thread.transact_vr, 0, 33 * sizeof(vector128));
	}
	/* Always get VRSAVE back */
	if (v_regs != NULL && tm_v_regs != NULL) {
		err |= __get_user(current->thread.vrsave,
				  (u32 __user *)&v_regs[33]);
		err |= __get_user(current->thread.transact_vrsave,
				  (u32 __user *)&tm_v_regs[33]);
	}
	else {
		current->thread.vrsave = 0;
		current->thread.transact_vrsave = 0;
	}
	if (cpu_has_feature(CPU_FTR_ALTIVEC))
		mtspr(SPRN_VRSAVE, current->thread.vrsave);
#endif /* CONFIG_ALTIVEC */
	/* restore floating point */
	err |= copy_fpr_from_user(current, &sc->fp_regs);
	err |= copy_transact_fpr_from_user(current, &tm_sc->fp_regs);
#ifdef CONFIG_VSX
	/*
	 * Get additional VSX data. Update v_regs to point after the
	 * VMX data.  Copy VSX low doubleword from userspace to local
	 * buffer for formatting, then into the taskstruct.
	 */
	if (v_regs && ((msr & MSR_VSX) != 0)) {
		v_regs += ELF_NVRREG;
		tm_v_regs += ELF_NVRREG;
		err |= copy_vsx_from_user(current, v_regs);
		err |= copy_transact_vsx_from_user(current, tm_v_regs);
	} else {
		for (i = 0; i < 32 ; i++) {
			current->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
			current->thread.transact_fp.fpr[i][TS_VSRLOWOFFSET] = 0;
		}
	}
#endif
	tm_enable();
	/* Make sure the transaction is marked as failed */
	current->thread.tm_texasr |= TEXASR_FS;
	/* This loads the checkpointed FP/VEC state, if used */
	tm_recheckpoint(&current->thread, msr);

	/* This loads the speculative FP/VEC state, if used */
	if (msr & MSR_FP) {
		do_load_up_transact_fpu(&current->thread);
		regs->msr |= (MSR_FP | current->thread.fpexc_mode);
	}
#ifdef CONFIG_ALTIVEC
	if (msr & MSR_VEC) {
		do_load_up_transact_altivec(&current->thread);
		regs->msr |= MSR_VEC;
	}
#endif

	return err;
}