Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 977 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
new file mode 100644
index 000000000..86bb5bb4c
--- /dev/null
+++ b/arch/powerpc/kernel/signal_64.c
@@ -0,0 +1,977 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  PowerPC version 
+ *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
+ *
+ *  Derived from "arch/i386/kernel/signal.c"
+ *    Copyright (C) 1991, 1992 Linus Torvalds
+ *    1997-11-28  Modified for POSIX.1b signals by Richard Henderson
+ */
+
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/kernel.h>
+#include <linux/signal.h>
+#include <linux/errno.h>
+#include <linux/wait.h>
+#include <linux/unistd.h>
+#include <linux/stddef.h>
+#include <linux/elf.h>
+#include <linux/ptrace.h>
+#include <linux/ratelimit.h>
+#include <linux/syscalls.h>
+#include <linux/pagemap.h>
+
+#include <asm/sigcontext.h>
+#include <asm/ucontext.h>
+#include <linux/uaccess.h>
+#include <asm/unistd.h>
+#include <asm/cacheflush.h>
+#include <asm/syscalls.h>
+#include <asm/vdso.h>
+#include <asm/switch_to.h>
+#include <asm/tm.h>
+#include <asm/asm-prototypes.h>
+
+#include "signal.h"
+
+
+#define GP_REGS_SIZE	min(sizeof(elf_gregset_t), sizeof(struct pt_regs))
+#define FP_REGS_SIZE	sizeof(elf_fpregset_t)
+
+#define TRAMP_TRACEBACK	4
+#define TRAMP_SIZE	7
+
+/*
+ * When we have signals to deliver, we set up on the user stack,
+ * going down from the original stack pointer:
+ *	1) a rt_sigframe struct which contains the ucontext	
+ *	2) a gap of __SIGNAL_FRAMESIZE bytes which acts as a dummy caller
+ *	   frame for the signal handler.
+ */
+
+struct rt_sigframe {
+	/* sys_rt_sigreturn requires the ucontext be the first field */
+	struct ucontext uc;
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+	struct ucontext uc_transact;
+#endif
+	unsigned long _unused[2];
+	unsigned int tramp[TRAMP_SIZE];
+	struct siginfo __user *pinfo;
+	void __user *puc;
+	struct siginfo info;
+	/* New 64 bit little-endian ABI allows redzone of 512 bytes below sp */
+	char abigap[USER_REDZONE_SIZE];
+} __attribute__ ((aligned (16)));
+
+unsigned long get_min_sigframe_size_64(void)
+{
+	return sizeof(struct rt_sigframe) + __SIGNAL_FRAMESIZE;
+}
+
+/*
+ * This computes a quad word aligned pointer inside the vmx_reserve array
+ * element. For historical reasons sigcontext might not be quad word aligned,
+ * but the location we write the VMX regs to must be. See the comment in
+ * sigcontext for more detail.
+ */
+#ifdef CONFIG_ALTIVEC
+static elf_vrreg_t __user *sigcontext_vmx_regs(struct sigcontext __user *sc)
+{
+	return (elf_vrreg_t __user *) (((unsigned long)sc->vmx_reserve + 15) & ~0xful);
+}
+#endif
+
+static void prepare_setup_sigcontext(struct task_struct *tsk)
+{
+#ifdef CONFIG_ALTIVEC
+	/* save altivec registers */
+	if (tsk->thread.used_vr)
+		flush_altivec_to_thread(tsk);
+	if (cpu_has_feature(CPU_FTR_ALTIVEC))
+		tsk->thread.vrsave = mfspr(SPRN_VRSAVE);
+#endif /* CONFIG_ALTIVEC */
+
+	flush_fp_to_thread(tsk);
+
+#ifdef CONFIG_VSX
+	if (tsk->thread.used_vsr)
+		flush_vsx_to_thread(tsk);
+#endif /* CONFIG_VSX */
+}
+
+/*
+ * Set up the sigcontext for the signal frame.
+ */
+
+#define unsafe_setup_sigcontext(sc, tsk, signr, set, handler, ctx_has_vsx_region, label)\
+do {											\
+	if (__unsafe_setup_sigcontext(sc, tsk, signr, set, handler, ctx_has_vsx_region))\
+		goto label;								\
+} while (0)
+static long notrace __unsafe_setup_sigcontext(struct sigcontext __user *sc,
+					struct task_struct *tsk, int signr, sigset_t *set,
+					unsigned long handler, int ctx_has_vsx_region)
+{
+	/* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the
+	 * process never used altivec yet (MSR_VEC is zero in pt_regs of
+	 * the context). This is very important because we must ensure we
+	 * don't lose the VRSAVE content that may have been set prior to
+	 * the process doing its first vector operation
+	 * Userland shall check AT_HWCAP to know whether it can rely on the
+	 * v_regs pointer or not
+	 */
+#ifdef CONFIG_ALTIVEC
+	elf_vrreg_t __user *v_regs = sigcontext_vmx_regs(sc);
+#endif
+	struct pt_regs *regs = tsk->thread.regs;
+	unsigned long msr = regs->msr;
+	/* Force usr to always see softe as 1 (interrupts enabled) */
+	unsigned long softe = 0x1;
+
+	BUG_ON(tsk != current);
+
+#ifdef CONFIG_ALTIVEC
+	unsafe_put_user(v_regs, &sc->v_regs, efault_out);
+
+	/* save altivec registers */
+	if (tsk->thread.used_vr) {
+		/* Copy 33 vec registers (vr0..31 and vscr) to the stack */
+		unsafe_copy_to_user(v_regs, &tsk->thread.vr_state,
+				    33 * sizeof(vector128), efault_out);
+		/* set MSR_VEC in the MSR value in the frame to indicate that sc->v_reg)
+		 * contains valid data.
+		 */
+		msr |= MSR_VEC;
+	}
+	/* We always copy to/from vrsave, it's 0 if we don't have or don't
+	 * use altivec.
+	 */
+	unsafe_put_user(tsk->thread.vrsave, (u32 __user *)&v_regs[33], efault_out);
+#else /* CONFIG_ALTIVEC */
+	unsafe_put_user(0, &sc->v_regs, efault_out);
+#endif /* CONFIG_ALTIVEC */
+	/* copy fpr regs and fpscr */
+	unsafe_copy_fpr_to_user(&sc->fp_regs, tsk, efault_out);
+
+	/*
+	 * Clear the MSR VSX bit to indicate there is no valid state attached
+	 * to this context, except in the specific case below where we set it.
+	 */
+	msr &= ~MSR_VSX;
+#ifdef CONFIG_VSX
+	/*
+	 * Copy VSX low doubleword to local buffer for formatting,
+	 * then out to userspace.  Update v_regs to point after the
+	 * VMX data.
+	 */
+	if (tsk->thread.used_vsr && ctx_has_vsx_region) {
+		v_regs += ELF_NVRREG;
+		unsafe_copy_vsx_to_user(v_regs, tsk, efault_out);
+		/* set MSR_VSX in the MSR value in the frame to
+		 * indicate that sc->vs_reg) contains valid data.
+		 */
+		msr |= MSR_VSX;
+	}
+#endif /* CONFIG_VSX */
+	unsafe_put_user(&sc->gp_regs, &sc->regs, efault_out);
+	unsafe_copy_to_user(&sc->gp_regs, regs, GP_REGS_SIZE, efault_out);
+	unsafe_put_user(msr, &sc->gp_regs[PT_MSR], efault_out);
+	unsafe_put_user(softe, &sc->gp_regs[PT_SOFTE], efault_out);
+	unsafe_put_user(signr, &sc->signal, efault_out);
+	unsafe_put_user(handler, &sc->handler, efault_out);
+	if (set != NULL)
+		unsafe_put_user(set->sig[0], &sc->oldmask, efault_out);
+
+	return 0;
+
+efault_out:
+	return -EFAULT;
+}
+
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+/*
+ * As above, but Transactional Memory is in use, so deliver sigcontexts
+ * containing checkpointed and transactional register states.
+ *
+ * To do this, we treclaim (done before entering here) to gather both sets of
+ * registers and set up the 'normal' sigcontext registers with rolled-back
+ * register values such that a simple signal handler sees a correct
+ * checkpointed register state.  If interested, a TM-aware sighandler can
+ * examine the transactional registers in the 2nd sigcontext to determine the
+ * real origin of the signal.
+ */
+static long setup_tm_sigcontexts(struct sigcontext __user *sc,
+				 struct sigcontext __user *tm_sc,
+				 struct task_struct *tsk,
+				 int signr, sigset_t *set, unsigned long handler,
+				 unsigned long msr)
+{
+	/* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the
+	 * process never used altivec yet (MSR_VEC is zero in pt_regs of
+	 * the context). This is very important because we must ensure we
+	 * don't lose the VRSAVE content that may have been set prior to
+	 * the process doing its first vector operation
+	 * Userland shall check AT_HWCAP to know wether it can rely on the
+	 * v_regs pointer or not.
+	 */
+#ifdef CONFIG_ALTIVEC
+	elf_vrreg_t __user *v_regs = sigcontext_vmx_regs(sc);
+	elf_vrreg_t __user *tm_v_regs = sigcontext_vmx_regs(tm_sc);
+#endif
+	struct pt_regs *regs = tsk->thread.regs;
+	long err = 0;
+
+	BUG_ON(tsk != current);
+
+	BUG_ON(!MSR_TM_ACTIVE(msr));
+
+	WARN_ON(tm_suspend_disabled);
+
+	/* Restore checkpointed FP, VEC, and VSX bits from ckpt_regs as
+	 * it contains the correct FP, VEC, VSX state after we treclaimed
+	 * the transaction and giveup_all() was called on reclaiming.
+	 */
+	msr |= tsk->thread.ckpt_regs.msr & (MSR_FP | MSR_VEC | MSR_VSX);
+
+#ifdef CONFIG_ALTIVEC
+	err |= __put_user(v_regs, &sc->v_regs);
+	err |= __put_user(tm_v_regs, &tm_sc->v_regs);
+
+	/* save altivec registers */
+	if (tsk->thread.used_vr) {
+		/* Copy 33 vec registers (vr0..31 and vscr) to the stack */
+		err |= __copy_to_user(v_regs, &tsk->thread.ckvr_state,
+				      33 * sizeof(vector128));
+		/* If VEC was enabled there are transactional VRs valid too,
+		 * else they're a copy of the checkpointed VRs.
+		 */
+		if (msr & MSR_VEC)
+			err |= __copy_to_user(tm_v_regs,
+					      &tsk->thread.vr_state,
+					      33 * sizeof(vector128));
+		else
+			err |= __copy_to_user(tm_v_regs,
+					      &tsk->thread.ckvr_state,
+					      33 * sizeof(vector128));
+
+		/* set MSR_VEC in the MSR value in the frame to indicate
+		 * that sc->v_reg contains valid data.
+		 */
+		msr |= MSR_VEC;
+	}
+	/* We always copy to/from vrsave, it's 0 if we don't have or don't
+	 * use altivec.
+	 */
+	if (cpu_has_feature(CPU_FTR_ALTIVEC))
+		tsk->thread.ckvrsave = mfspr(SPRN_VRSAVE);
+	err |= __put_user(tsk->thread.ckvrsave, (u32 __user *)&v_regs[33]);
+	if (msr & MSR_VEC)
+		err |= __put_user(tsk->thread.vrsave,
+				  (u32 __user *)&tm_v_regs[33]);
+	else
+		err |= __put_user(tsk->thread.ckvrsave,
+				  (u32 __user *)&tm_v_regs[33]);
+
+#else /* CONFIG_ALTIVEC */
+	err |= __put_user(0, &sc->v_regs);
+	err |= __put_user(0, &tm_sc->v_regs);
+#endif /* CONFIG_ALTIVEC */
+
+	/* copy fpr regs and fpscr */
+	err |= copy_ckfpr_to_user(&sc->fp_regs, tsk);
+	if (msr & MSR_FP)
+		err |= copy_fpr_to_user(&tm_sc->fp_regs, tsk);
+	else
+		err |= copy_ckfpr_to_user(&tm_sc->fp_regs, tsk);
+
+#ifdef CONFIG_VSX
+	/*
+	 * Copy VSX low doubleword to local buffer for formatting,
+	 * then out to userspace.  Update v_regs to point after the
+	 * VMX data.
+	 */
+	if (tsk->thread.used_vsr) {
+		v_regs += ELF_NVRREG;
+		tm_v_regs += ELF_NVRREG;
+
+		err |= copy_ckvsx_to_user(v_regs, tsk);
+
+		if (msr & MSR_VSX)
+			err |= copy_vsx_to_user(tm_v_regs, tsk);
+		else
+			err |= copy_ckvsx_to_user(tm_v_regs, tsk);
+
+		/* set MSR_VSX in the MSR value in the frame to
+		 * indicate that sc->vs_reg) contains valid data.
+		 */
+		msr |= MSR_VSX;
+	}
+#endif /* CONFIG_VSX */
+
+	err |= __put_user(&sc->gp_regs, &sc->regs);
+	err |= __put_user(&tm_sc->gp_regs, &tm_sc->regs);
+	err |= __copy_to_user(&tm_sc->gp_regs, regs, GP_REGS_SIZE);
+	err |= __copy_to_user(&sc->gp_regs,
+			      &tsk->thread.ckpt_regs, GP_REGS_SIZE);
+	err |= __put_user(msr, &tm_sc->gp_regs[PT_MSR]);
+	err |= __put_user(msr, &sc->gp_regs[PT_MSR]);
+	err |= __put_user(signr, &sc->signal);
+	err |= __put_user(handler, &sc->handler);
+	if (set != NULL)
+		err |=  __put_user(set->sig[0], &sc->oldmask);
+
+	return err;
+}
+#endif
+
+/*
+ * Restore the sigcontext from the signal frame.
+ */
+#define unsafe_restore_sigcontext(tsk, set, sig, sc, label) do {	\
+	if (__unsafe_restore_sigcontext(tsk, set, sig, sc))		\
+		goto label;						\
+} while (0)
+static long notrace __unsafe_restore_sigcontext(struct task_struct *tsk, sigset_t *set,
+						int sig, struct sigcontext __user *sc)
+{
+#ifdef CONFIG_ALTIVEC
+	elf_vrreg_t __user *v_regs;
+#endif
+	unsigned long save_r13 = 0;
+	unsigned long msr;
+	struct pt_regs *regs = tsk->thread.regs;
+#ifdef CONFIG_VSX
+	int i;
+#endif
+
+	BUG_ON(tsk != current);
+
+	/* If this is not a signal return, we preserve the TLS in r13 */
+	if (!sig)
+		save_r13 = regs->gpr[13];
+
+	/* copy the GPRs */
+	unsafe_copy_from_user(regs->gpr, sc->gp_regs, sizeof(regs->gpr), efault_out);
+	unsafe_get_user(regs->nip, &sc->gp_regs[PT_NIP], efault_out);
+	/* get MSR separately, transfer the LE bit if doing signal return */
+	unsafe_get_user(msr, &sc->gp_regs[PT_MSR], efault_out);
+	if (sig)
+		regs_set_return_msr(regs, (regs->msr & ~MSR_LE) | (msr & MSR_LE));
+	unsafe_get_user(regs->orig_gpr3, &sc->gp_regs[PT_ORIG_R3], efault_out);
+	unsafe_get_user(regs->ctr, &sc->gp_regs[PT_CTR], efault_out);
+	unsafe_get_user(regs->link, &sc->gp_regs[PT_LNK], efault_out);
+	unsafe_get_user(regs->xer, &sc->gp_regs[PT_XER], efault_out);
+	unsafe_get_user(regs->ccr, &sc->gp_regs[PT_CCR], efault_out);
+	/* Don't allow userspace to set SOFTE */
+	set_trap_norestart(regs);
+	unsafe_get_user(regs->dar, &sc->gp_regs[PT_DAR], efault_out);
+	unsafe_get_user(regs->dsisr, &sc->gp_regs[PT_DSISR], efault_out);
+	unsafe_get_user(regs->result, &sc->gp_regs[PT_RESULT], efault_out);
+
+	if (!sig)
+		regs->gpr[13] = save_r13;
+	if (set != NULL)
+		unsafe_get_user(set->sig[0], &sc->oldmask, efault_out);
+
+	/*
+	 * Force reload of FP/VEC/VSX so userspace sees any changes.
+	 * Clear these bits from the user process' MSR before copying into the
+	 * thread struct. If we are rescheduled or preempted and another task
+	 * uses FP/VEC/VSX, and this process has the MSR bits set, then the
+	 * context switch code will save the current CPU state into the
+	 * thread_struct - possibly overwriting the data we are updating here.
+	 */
+	regs_set_return_msr(regs, regs->msr & ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC | MSR_VSX));
+
+#ifdef CONFIG_ALTIVEC
+	unsafe_get_user(v_regs, &sc->v_regs, efault_out);
+	if (v_regs && !access_ok(v_regs, 34 * sizeof(vector128)))
+		return -EFAULT;
+	/* Copy 33 vec registers (vr0..31 and vscr) from the stack */
+	if (v_regs != NULL && (msr & MSR_VEC) != 0) {
+		unsafe_copy_from_user(&tsk->thread.vr_state, v_regs,
+				      33 * sizeof(vector128), efault_out);
+		tsk->thread.used_vr = true;
+	} else if (tsk->thread.used_vr) {
+		memset(&tsk->thread.vr_state, 0, 33 * sizeof(vector128));
+	}
+	/* Always get VRSAVE back */
+	if (v_regs != NULL)
+		unsafe_get_user(tsk->thread.vrsave, (u32 __user *)&v_regs[33], efault_out);
+	else
+		tsk->thread.vrsave = 0;
+	if (cpu_has_feature(CPU_FTR_ALTIVEC))
+		mtspr(SPRN_VRSAVE, tsk->thread.vrsave);
+#endif /* CONFIG_ALTIVEC */
+	/* restore floating point */
+	unsafe_copy_fpr_from_user(tsk, &sc->fp_regs, efault_out);
+#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.
+	 */
+	v_regs += ELF_NVRREG;
+	if ((msr & MSR_VSX) != 0) {
+		unsafe_copy_vsx_from_user(tsk, v_regs, efault_out);
+		tsk->thread.used_vsr = true;
+	} else {
+		for (i = 0; i < 32 ; i++)
+			tsk->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
+	}
+#endif
+	return 0;
+
+efault_out:
+	return -EFAULT;
+}
+
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+/*
+ * Restore the two sigcontexts from the frame of a transactional processes.
+ */
+
+static long restore_tm_sigcontexts(struct task_struct *tsk,
+				   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;
+	struct pt_regs *regs = tsk->thread.regs;
+#ifdef CONFIG_VSX
+	int i;
+#endif
+
+	BUG_ON(tsk != current);
+
+	if (tm_suspend_disabled)
+		return -EINVAL;
+
+	/* copy the GPRs */
+	err |= __copy_from_user(regs->gpr, tm_sc->gp_regs, sizeof(regs->gpr));
+	err |= __copy_from_user(&tsk->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(tsk->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 LE from user context */
+	regs_set_return_msr(regs, (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(tsk->thread.ckpt_regs.ctr,
+			  &sc->gp_regs[PT_CTR]);
+	err |= __get_user(tsk->thread.ckpt_regs.link,
+			  &sc->gp_regs[PT_LNK]);
+	err |= __get_user(tsk->thread.ckpt_regs.xer,
+			  &sc->gp_regs[PT_XER]);
+	err |= __get_user(tsk->thread.ckpt_regs.ccr,
+			  &sc->gp_regs[PT_CCR]);
+	/* Don't allow userspace to set SOFTE */
+	set_trap_norestart(regs);
+	/* These regs are not checkpointed; they can go in 'regs'. */
+	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]);
+
+	/*
+	 * Force reload of FP/VEC.
+	 * This has to be done before copying stuff into tsk->thread.fpr/vr
+	 * for the reasons explained in the previous comment.
+	 */
+	regs_set_return_msr(regs, 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(v_regs, 34 * sizeof(vector128)))
+		return -EFAULT;
+	if (tm_v_regs && !access_ok(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(&tsk->thread.ckvr_state, v_regs,
+					33 * sizeof(vector128));
+		err |= __copy_from_user(&tsk->thread.vr_state, tm_v_regs,
+					33 * sizeof(vector128));
+		current->thread.used_vr = true;
+	}
+	else if (tsk->thread.used_vr) {
+		memset(&tsk->thread.vr_state, 0, 33 * sizeof(vector128));
+		memset(&tsk->thread.ckvr_state, 0, 33 * sizeof(vector128));
+	}
+	/* Always get VRSAVE back */
+	if (v_regs != NULL && tm_v_regs != NULL) {
+		err |= __get_user(tsk->thread.ckvrsave,
+				  (u32 __user *)&v_regs[33]);
+		err |= __get_user(tsk->thread.vrsave,
+				  (u32 __user *)&tm_v_regs[33]);
+	}
+	else {
+		tsk->thread.vrsave = 0;
+		tsk->thread.ckvrsave = 0;
+	}
+	if (cpu_has_feature(CPU_FTR_ALTIVEC))
+		mtspr(SPRN_VRSAVE, tsk->thread.vrsave);
+#endif /* CONFIG_ALTIVEC */
+	/* restore floating point */
+	err |= copy_fpr_from_user(tsk, &tm_sc->fp_regs);
+	err |= copy_ckfpr_from_user(tsk, &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(tsk, tm_v_regs);
+		err |= copy_ckvsx_from_user(tsk, v_regs);
+		tsk->thread.used_vsr = true;
+	} else {
+		for (i = 0; i < 32 ; i++) {
+			tsk->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
+			tsk->thread.ckfp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
+		}
+	}
+#endif
+	tm_enable();
+	/* Make sure the transaction is marked as failed */
+	tsk->thread.tm_texasr |= TEXASR_FS;
+
+	/*
+	 * Disabling preemption, since it is unsafe to be preempted
+	 * with MSR[TS] set without recheckpointing.
+	 */
+	preempt_disable();
+
+	/* pull in MSR TS bits from user context */
+	regs_set_return_msr(regs, regs->msr | (msr & MSR_TS_MASK));
+
+	/*
+	 * Ensure that TM is enabled in regs->msr before we leave the signal
+	 * handler. It could be the case that (a) user disabled the TM bit
+	 * through the manipulation of the MSR bits in uc_mcontext or (b) the
+	 * TM bit was disabled because a sufficient number of context switches
+	 * happened whilst in the signal handler and load_tm overflowed,
+	 * disabling the TM bit. In either case we can end up with an illegal
+	 * TM state leading to a TM Bad Thing when we return to userspace.
+	 *
+	 * CAUTION:
+	 * After regs->MSR[TS] being updated, make sure that get_user(),
+	 * put_user() or similar functions are *not* called. These
+	 * functions can generate page faults which will cause the process
+	 * to be de-scheduled with MSR[TS] set but without calling
+	 * tm_recheckpoint(). This can cause a bug.
+	 */
+	regs_set_return_msr(regs, regs->msr | MSR_TM);
+
+	/* This loads the checkpointed FP/VEC state, if used */
+	tm_recheckpoint(&tsk->thread);
+
+	msr_check_and_set(msr & (MSR_FP | MSR_VEC));
+	if (msr & MSR_FP) {
+		load_fp_state(&tsk->thread.fp_state);
+		regs_set_return_msr(regs, regs->msr | (MSR_FP | tsk->thread.fpexc_mode));
+	}
+	if (msr & MSR_VEC) {
+		load_vr_state(&tsk->thread.vr_state);
+		regs_set_return_msr(regs, regs->msr | MSR_VEC);
+	}
+
+	preempt_enable();
+
+	return err;
+}
+#else /* !CONFIG_PPC_TRANSACTIONAL_MEM */
+static long restore_tm_sigcontexts(struct task_struct *tsk, struct sigcontext __user *sc,
+				   struct sigcontext __user *tm_sc)
+{
+	return -EINVAL;
+}
+#endif
+
+/*
+ * Setup the trampoline code on the stack
+ */
+static long setup_trampoline(unsigned int syscall, unsigned int __user *tramp)
+{
+	int i;
+	long err = 0;
+
+	/* Call the handler and pop the dummy stackframe*/
+	err |= __put_user(PPC_RAW_BCTRL(), &tramp[0]);
+	err |= __put_user(PPC_RAW_ADDI(_R1, _R1, __SIGNAL_FRAMESIZE), &tramp[1]);
+
+	err |= __put_user(PPC_RAW_LI(_R0, syscall), &tramp[2]);
+	err |= __put_user(PPC_RAW_SC(), &tramp[3]);
+
+	/* Minimal traceback info */
+	for (i=TRAMP_TRACEBACK; i < TRAMP_SIZE ;i++)
+		err |= __put_user(0, &tramp[i]);
+
+	if (!err)
+		flush_icache_range((unsigned long) &tramp[0],
+			   (unsigned long) &tramp[TRAMP_SIZE]);
+
+	return err;
+}
+
+/*
+ * Userspace code may pass a ucontext which doesn't include VSX added
+ * at the end.  We need to check for this case.
+ */
+#define UCONTEXTSIZEWITHOUTVSX \
+		(sizeof(struct ucontext) - 32*sizeof(long))
+
+/*
+ * Handle {get,set,swap}_context operations
+ */
+SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx,
+		struct ucontext __user *, new_ctx, long, ctx_size)
+{
+	sigset_t set;
+	unsigned long new_msr = 0;
+	int ctx_has_vsx_region = 0;
+
+	if (new_ctx &&
+	    get_user(new_msr, &new_ctx->uc_mcontext.gp_regs[PT_MSR]))
+		return -EFAULT;
+	/*
+	 * Check that the context is not smaller than the original
+	 * size (with VMX but without VSX)
+	 */
+	if (ctx_size < UCONTEXTSIZEWITHOUTVSX)
+		return -EINVAL;
+	/*
+	 * If the new context state sets the MSR VSX bits but
+	 * it doesn't provide VSX state.
+	 */
+	if ((ctx_size < sizeof(struct ucontext)) &&
+	    (new_msr & MSR_VSX))
+		return -EINVAL;
+	/* Does the context have enough room to store VSX data? */
+	if (ctx_size >= sizeof(struct ucontext))
+		ctx_has_vsx_region = 1;
+
+	if (old_ctx != NULL) {
+		prepare_setup_sigcontext(current);
+		if (!user_write_access_begin(old_ctx, ctx_size))
+			return -EFAULT;
+
+		unsafe_setup_sigcontext(&old_ctx->uc_mcontext, current, 0, NULL,
+					0, ctx_has_vsx_region, efault_out);
+		unsafe_copy_to_user(&old_ctx->uc_sigmask, &current->blocked,
+				    sizeof(sigset_t), efault_out);
+
+		user_write_access_end();
+	}
+	if (new_ctx == NULL)
+		return 0;
+	if (!access_ok(new_ctx, ctx_size) ||
+	    fault_in_readable((char __user *)new_ctx, ctx_size))
+		return -EFAULT;
+
+	/*
+	 * If we get a fault copying the context into the kernel's
+	 * image of the user's registers, we can't just return -EFAULT
+	 * because the user's registers will be corrupted.  For instance
+	 * the NIP value may have been updated but not some of the
+	 * other registers.  Given that we have done the access_ok
+	 * and successfully read the first and last bytes of the region
+	 * above, this should only happen in an out-of-memory situation
+	 * or if another thread unmaps the region containing the context.
+	 * We kill the task with a SIGSEGV in this situation.
+	 */
+
+	if (__get_user_sigset(&set, &new_ctx->uc_sigmask)) {
+		force_exit_sig(SIGSEGV);
+		return -EFAULT;
+	}
+	set_current_blocked(&set);
+
+	if (!user_read_access_begin(new_ctx, ctx_size))
+		return -EFAULT;
+	if (__unsafe_restore_sigcontext(current, NULL, 0, &new_ctx->uc_mcontext)) {
+		user_read_access_end();
+		force_exit_sig(SIGSEGV);
+		return -EFAULT;
+	}
+	user_read_access_end();
+
+	/* This returns like rt_sigreturn */
+	set_thread_flag(TIF_RESTOREALL);
+
+	return 0;
+
+efault_out:
+	user_write_access_end();
+	return -EFAULT;
+}
+
+
+/*
+ * Do a signal return; undo the signal stack.
+ */
+
+SYSCALL_DEFINE0(rt_sigreturn)
+{
+	struct pt_regs *regs = current_pt_regs();
+	struct ucontext __user *uc = (struct ucontext __user *)regs->gpr[1];
+	sigset_t set;
+	unsigned long msr;
+
+	/* Always make any pending restarted system calls return -EINTR */
+	current->restart_block.fn = do_no_restart_syscall;
+
+	if (!access_ok(uc, sizeof(*uc)))
+		goto badframe;
+
+	if (__get_user_sigset(&set, &uc->uc_sigmask))
+		goto badframe;
+	set_current_blocked(&set);
+
+	if (IS_ENABLED(CONFIG_PPC_TRANSACTIONAL_MEM)) {
+		/*
+		 * If there is a transactional state then throw it away.
+		 * The purpose of a sigreturn is to destroy all traces of the
+		 * signal frame, this includes any transactional state created
+		 * within in. We only check for suspended as we can never be
+		 * active in the kernel, we are active, there is nothing better to
+		 * do than go ahead and Bad Thing later.
+		 * The cause is not important as there will never be a
+		 * recheckpoint so it's not user visible.
+		 */
+		if (MSR_TM_SUSPENDED(mfmsr()))
+			tm_reclaim_current(0);
+
+		/*
+		 * Disable MSR[TS] bit also, so, if there is an exception in the
+		 * code below (as a page fault in copy_ckvsx_to_user()), it does
+		 * not recheckpoint this task if there was a context switch inside
+		 * the exception.
+		 *
+		 * A major page fault can indirectly call schedule(). A reschedule
+		 * process in the middle of an exception can have a side effect
+		 * (Changing the CPU MSR[TS] state), since schedule() is called
+		 * with the CPU MSR[TS] disable and returns with MSR[TS]=Suspended
+		 * (switch_to() calls tm_recheckpoint() for the 'new' process). In
+		 * this case, the process continues to be the same in the CPU, but
+		 * the CPU state just changed.
+		 *
+		 * This can cause a TM Bad Thing, since the MSR in the stack will
+		 * have the MSR[TS]=0, and this is what will be used to RFID.
+		 *
+		 * Clearing MSR[TS] state here will avoid a recheckpoint if there
+		 * is any process reschedule in kernel space. The MSR[TS] state
+		 * does not need to be saved also, since it will be replaced with
+		 * the MSR[TS] that came from user context later, at
+		 * restore_tm_sigcontexts.
+		 */
+		regs_set_return_msr(regs, regs->msr & ~MSR_TS_MASK);
+
+		if (__get_user(msr, &uc->uc_mcontext.gp_regs[PT_MSR]))
+			goto badframe;
+	}
+
+	if (IS_ENABLED(CONFIG_PPC_TRANSACTIONAL_MEM) && MSR_TM_ACTIVE(msr)) {
+		/* We recheckpoint on return. */
+		struct ucontext __user *uc_transact;
+
+		/* Trying to start TM on non TM system */
+		if (!cpu_has_feature(CPU_FTR_TM))
+			goto badframe;
+
+		if (__get_user(uc_transact, &uc->uc_link))
+			goto badframe;
+		if (restore_tm_sigcontexts(current, &uc->uc_mcontext,
+					   &uc_transact->uc_mcontext))
+			goto badframe;
+	} else {
+		/*
+		 * Fall through, for non-TM restore
+		 *
+		 * Unset MSR[TS] on the thread regs since MSR from user
+		 * context does not have MSR active, and recheckpoint was
+		 * not called since restore_tm_sigcontexts() was not called
+		 * also.
+		 *
+		 * If not unsetting it, the code can RFID to userspace with
+		 * MSR[TS] set, but without CPU in the proper state,
+		 * causing a TM bad thing.
+		 */
+		regs_set_return_msr(current->thread.regs,
+				current->thread.regs->msr & ~MSR_TS_MASK);
+		if (!user_read_access_begin(&uc->uc_mcontext, sizeof(uc->uc_mcontext)))
+			goto badframe;
+
+		unsafe_restore_sigcontext(current, NULL, 1, &uc->uc_mcontext,
+					  badframe_block);
+
+		user_read_access_end();
+	}
+
+	if (restore_altstack(&uc->uc_stack))
+		goto badframe;
+
+	set_thread_flag(TIF_RESTOREALL);
+
+	return 0;
+
+badframe_block:
+	user_read_access_end();
+badframe:
+	signal_fault(current, regs, "rt_sigreturn", uc);
+
+	force_sig(SIGSEGV);
+	return 0;
+}
+
+int handle_rt_signal64(struct ksignal *ksig, sigset_t *set,
+		struct task_struct *tsk)
+{
+	struct rt_sigframe __user *frame;
+	unsigned long newsp = 0;
+	long err = 0;
+	struct pt_regs *regs = tsk->thread.regs;
+	/* Save the thread's msr before get_tm_stackpointer() changes it */
+	unsigned long msr = regs->msr;
+
+	frame = get_sigframe(ksig, tsk, sizeof(*frame), 0);
+
+	/*
+	 * This only applies when calling unsafe_setup_sigcontext() and must be
+	 * called before opening the uaccess window.
+	 */
+	if (!MSR_TM_ACTIVE(msr))
+		prepare_setup_sigcontext(tsk);
+
+	if (!user_write_access_begin(frame, sizeof(*frame)))
+		goto badframe;
+
+	unsafe_put_user(&frame->info, &frame->pinfo, badframe_block);
+	unsafe_put_user(&frame->uc, &frame->puc, badframe_block);
+
+	/* Create the ucontext.  */
+	unsafe_put_user(0, &frame->uc.uc_flags, badframe_block);
+	unsafe_save_altstack(&frame->uc.uc_stack, regs->gpr[1], badframe_block);
+
+	if (MSR_TM_ACTIVE(msr)) {
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+		/* The ucontext_t passed to userland points to the second
+		 * ucontext_t (for transactional state) with its uc_link ptr.
+		 */
+		unsafe_put_user(&frame->uc_transact, &frame->uc.uc_link, badframe_block);
+
+		user_write_access_end();
+
+		err |= setup_tm_sigcontexts(&frame->uc.uc_mcontext,
+					    &frame->uc_transact.uc_mcontext,
+					    tsk, ksig->sig, NULL,
+					    (unsigned long)ksig->ka.sa.sa_handler,
+					    msr);
+
+		if (!user_write_access_begin(&frame->uc.uc_sigmask,
+					     sizeof(frame->uc.uc_sigmask)))
+			goto badframe;
+
+#endif
+	} else {
+		unsafe_put_user(0, &frame->uc.uc_link, badframe_block);
+		unsafe_setup_sigcontext(&frame->uc.uc_mcontext, tsk, ksig->sig,
+					NULL, (unsigned long)ksig->ka.sa.sa_handler,
+					1, badframe_block);
+	}
+
+	unsafe_copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set), badframe_block);
+	user_write_access_end();
+
+	/* Save the siginfo outside of the unsafe block. */
+	if (copy_siginfo_to_user(&frame->info, &ksig->info))
+		goto badframe;
+
+	/* Make sure signal handler doesn't get spurious FP exceptions */
+	tsk->thread.fp_state.fpscr = 0;
+
+	/* Set up to return from userspace. */
+	if (tsk->mm->context.vdso) {
+		regs_set_return_ip(regs, VDSO64_SYMBOL(tsk->mm->context.vdso, sigtramp_rt64));
+	} else {
+		err |= setup_trampoline(__NR_rt_sigreturn, &frame->tramp[0]);
+		if (err)
+			goto badframe;
+		regs_set_return_ip(regs, (unsigned long) &frame->tramp[0]);
+	}
+
+	/* Allocate a dummy caller frame for the signal handler. */
+	newsp = ((unsigned long)frame) - __SIGNAL_FRAMESIZE;
+	err |= put_user(regs->gpr[1], (unsigned long __user *)newsp);
+
+	/* Set up "regs" so we "return" to the signal handler. */
+	if (is_elf2_task()) {
+		regs->ctr = (unsigned long) ksig->ka.sa.sa_handler;
+		regs->gpr[12] = regs->ctr;
+	} else {
+		/* Handler is *really* a pointer to the function descriptor for
+		 * the signal routine.  The first entry in the function
+		 * descriptor is the entry address of signal and the second
+		 * entry is the TOC value we need to use.
+		 */
+		struct func_desc __user *ptr =
+			(struct func_desc __user *)ksig->ka.sa.sa_handler;
+
+		err |= get_user(regs->ctr, &ptr->addr);
+		err |= get_user(regs->gpr[2], &ptr->toc);
+	}
+
+	/* enter the signal handler in native-endian mode */
+	regs_set_return_msr(regs, (regs->msr & ~MSR_LE) | (MSR_KERNEL & MSR_LE));
+	regs->gpr[1] = newsp;
+	regs->gpr[3] = ksig->sig;
+	regs->result = 0;
+	if (ksig->ka.sa.sa_flags & SA_SIGINFO) {
+		regs->gpr[4] = (unsigned long)&frame->info;
+		regs->gpr[5] = (unsigned long)&frame->uc;
+		regs->gpr[6] = (unsigned long) frame;
+	} else {
+		regs->gpr[4] = (unsigned long)&frame->uc.uc_mcontext;
+	}
+	if (err)
+		goto badframe;
+
+	return 0;
+
+badframe_block:
+	user_write_access_end();
+badframe:
+	signal_fault(current, regs, "handle_rt_signal64", frame);
+
+	return 1;
+}