text: /*
   *  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
   *
   *  This program is free software; you can redistribute it and/or
   *  modify it under the terms of the GNU General Public License
   *  as published by the Free Software Foundation; either version
   *  2 of the License, or (at your option) any later version.
   */
  
  #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 <asm/sigcontext.h>
  #include <asm/ucontext.h>
  #include <asm/uaccess.h>
  #include <asm/pgtable.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 "signal.h"
  
  #define DEBUG_SIG 0
  
  #define GP_REGS_SIZE	min(sizeof(elf_gregset_t), sizeof(struct pt_regs))
  #define FP_REGS_SIZE	sizeof(elf_fpregset_t)
  
  #define TRAMP_TRACEBACK	3
  #define TRAMP_SIZE	6
  
  /*
   * 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)));
  
  static const char fmt32[] = KERN_INFO \
  	"%s[%d]: bad frame in %s: %08lx nip %08lx lr %08lx\n";
  static const char fmt64[] = KERN_INFO \
  	"%s[%d]: bad frame in %s: %016lx nip %016lx lr %016lx\n";
  
  /*
   * Set up the sigcontext for the signal frame.
   */
  
  static long setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
  		 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 = (elf_vrreg_t __user *)(((unsigned long)sc->vmx_reserve + 15) & ~0xful);
  #endif
  	unsigned long msr = regs->msr;
  	long err = 0;
  
  #ifdef CONFIG_ALTIVEC
  	err |= __put_user(v_regs, &sc->v_regs);
  
  	/* save altivec registers */
  	if (current->thread.used_vr) {
  		flush_altivec_to_thread(current);
  		/* Copy 33 vec registers (vr0..31 and vscr) to the stack */
  		err |= __copy_to_user(v_regs, &current->thread.vr_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))
  		current->thread.vrsave = mfspr(SPRN_VRSAVE);
  	err |= __put_user(current->thread.vrsave, (u32 __user *)&v_regs[33]);
  #else /* CONFIG_ALTIVEC */
  	err |= __put_user(0, &sc->v_regs);
  #endif /* CONFIG_ALTIVEC */
  	flush_fp_to_thread(current);
  	/* copy fpr regs and fpscr */
  	err |= copy_fpr_to_user(&sc->fp_regs, current);
  
  	/*
  	 * 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 (current->thread.used_vsr && ctx_has_vsx_region) {
  		__giveup_vsx(current);
  		v_regs += ELF_NVRREG;
  		err |= copy_vsx_to_user(v_regs, current);
  		/* 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);
  	WARN_ON(!FULL_REGS(regs));
  	err |= __copy_to_user(&sc->gp_regs, regs, GP_REGS_SIZE);
  	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;
  }
  
  #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 pt_regs *regs,
  				 int signr, sigset_t *set, unsigned long handler)
  {
  	/* 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 = (elf_vrreg_t __user *)
  		(((unsigned long)sc->vmx_reserve + 15) & ~0xful);
  	elf_vrreg_t __user *tm_v_regs = (elf_vrreg_t __user *)
  		(((unsigned long)tm_sc->vmx_reserve + 15) & ~0xful);
  #endif
  	unsigned long msr = regs->msr;
  	long err = 0;
  
  	BUG_ON(!MSR_TM_ACTIVE(regs->msr));
  
  	flush_fp_to_thread(current);
  
  #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 (current->thread.used_vr) {
  		flush_altivec_to_thread(current);
  		/* Copy 33 vec registers (vr0..31 and vscr) to the stack */
  		err |= __copy_to_user(v_regs, &current->thread.vr_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,
  					      &current->thread.transact_vr,
  					      33 * sizeof(vector128));
  		else
  			err |= __copy_to_user(tm_v_regs,
  					      &current->thread.vr_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))
  		current->thread.vrsave = mfspr(SPRN_VRSAVE);
  	err |= __put_user(current->thread.vrsave, (u32 __user *)&v_regs[33]);
  	if (msr & MSR_VEC)
  		err |= __put_user(current->thread.transact_vrsave,
  				  (u32 __user *)&tm_v_regs[33]);
  	else
  		err |= __put_user(current->thread.vrsave,
  				  (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_fpr_to_user(&sc->fp_regs, current);
  	if (msr & MSR_FP)
  		err |= copy_transact_fpr_to_user(&tm_sc->fp_regs, current);
  	else
  		err |= copy_fpr_to_user(&tm_sc->fp_regs, current);
  
  #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 (current->thread.used_vsr) {
  		__giveup_vsx(current);
  		v_regs += ELF_NVRREG;
  		tm_v_regs += ELF_NVRREG;
  
  		err |= copy_vsx_to_user(v_regs, current);
  
  		if (msr & MSR_VSX)
  			err |= copy_transact_vsx_to_user(tm_v_regs, current);
  		else
  			err |= copy_vsx_to_user(tm_v_regs, current);
  
  		/* 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);
  	WARN_ON(!FULL_REGS(regs));
  	err |= __copy_to_user(&tm_sc->gp_regs, regs, GP_REGS_SIZE);
  	err |= __copy_to_user(&sc->gp_regs,
  			      &current->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.
   */
  
  static long restore_sigcontext(struct pt_regs *regs, sigset_t *set, int sig,
  			      struct sigcontext __user *sc)
  {
  #ifdef CONFIG_ALTIVEC
  	elf_vrreg_t __user *v_regs;
  #endif
  	unsigned long err = 0;
  	unsigned long save_r13 = 0;
  	unsigned long msr;
  #ifdef CONFIG_VSX
  	int i;
  #endif
  
  	/* If this is not a signal return, we preserve the TLS in r13 */
  	if (!sig)
  		save_r13 = regs->gpr[13];
  
  	/* copy the GPRs */
  	err |= __copy_from_user(regs->gpr, sc->gp_regs, sizeof(regs->gpr));
  	err |= __get_user(regs->nip, &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]);
  	if (sig)
  		regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE);
  	err |= __get_user(regs->orig_gpr3, &sc->gp_regs[PT_ORIG_R3]);
  	err |= __get_user(regs->ctr, &sc->gp_regs[PT_CTR]);
  	err |= __get_user(regs->link, &sc->gp_regs[PT_LNK]);
  	err |= __get_user(regs->xer, &sc->gp_regs[PT_XER]);
  	err |= __get_user(regs->ccr, &sc->gp_regs[PT_CCR]);
  	/* skip SOFTE */
  	regs->trap = 0;
  	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]);
  
  	if (!sig)
  		regs->gpr[13] = save_r13;
  	if (set != NULL)
  		err |=  __get_user(set->sig[0], &sc->oldmask);
  
  	/*
  	 * 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);
  	if (err)
  		return err;
  	if (v_regs && !access_ok(VERIFY_READ, 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)
  		err |= __copy_from_user(&current->thread.vr_state, v_regs,
  					33 * sizeof(vector128));
  	else if (current->thread.used_vr)
  		memset(&current->thread.vr_state, 0, 33 * sizeof(vector128));
  	/* Always get VRSAVE back */
  	if (v_regs != NULL)
  		err |= __get_user(current->thread.vrsave, (u32 __user *)&v_regs[33]);
  	else
  		current->thread.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);
  #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)
  		err |= copy_vsx_from_user(current, v_regs);
  	else
  		for (i = 0; i < 32 ; i++)
  			current->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
  #endif
  	return err;
  }
  
  #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
  /*
   * Restore the two sigcontexts from the frame of a transactional processes.
   */
  
  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]);
  	/* 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();
  	/* 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;
  }
  #endif
  
  /*
   * Setup the trampoline code on the stack
   */
  static long setup_trampoline(unsigned int syscall, unsigned int __user *tramp)
  {
  	int i;
  	long err = 0;
  
  	/* addi r1, r1, __SIGNAL_FRAMESIZE  # Pop the dummy stackframe */
  	err |= __put_user(0x38210000UL | (__SIGNAL_FRAMESIZE & 0xffff), &tramp[0]);
  	/* li r0, __NR_[rt_]sigreturn| */
  	err |= __put_user(0x38000000UL | (syscall & 0xffff), &tramp[1]);
  	/* sc */
  	err |= __put_user(0x44000002UL, &tramp[2]);
  
  	/* 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
   */
  int sys_swapcontext(struct ucontext __user *old_ctx,
  		    struct ucontext __user *new_ctx,
  		    long ctx_size, long r6, long r7, long r8, struct pt_regs *regs)
  {
  	unsigned char tmp;
  	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) {
  		if (!access_ok(VERIFY_WRITE, old_ctx, ctx_size)
  		    || setup_sigcontext(&old_ctx->uc_mcontext, regs, 0, NULL, 0,
  					ctx_has_vsx_region)
  		    || __copy_to_user(&old_ctx->uc_sigmask,
  				      &current->blocked, sizeof(sigset_t)))
  			return -EFAULT;
  	}
  	if (new_ctx == NULL)
  		return 0;
  	if (!access_ok(VERIFY_READ, new_ctx, ctx_size)
  	    || __get_user(tmp, (u8 __user *) new_ctx)
  	    || __get_user(tmp, (u8 __user *) new_ctx + ctx_size - 1))
  		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 (__copy_from_user(&set, &new_ctx->uc_sigmask, sizeof(set)))
  		do_exit(SIGSEGV);
  	set_current_blocked(&set);
  	if (restore_sigcontext(regs, NULL, 0, &new_ctx->uc_mcontext))
  		do_exit(SIGSEGV);
  
  	/* This returns like rt_sigreturn */
  	set_thread_flag(TIF_RESTOREALL);
  	return 0;
  }
  
  
  /*
   * Do a signal return; undo the signal stack.
   */
  
  int sys_rt_sigreturn(unsigned long r3, unsigned long r4, unsigned long r5,
  		     unsigned long r6, unsigned long r7, unsigned long r8,
  		     struct pt_regs *regs)
  {
  	struct ucontext __user *uc = (struct ucontext __user *)regs->gpr[1];
  	sigset_t set;
  #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
  	unsigned long msr;
  #endif
  
  	/* Always make any pending restarted system calls return -EINTR */
  	current_thread_info()->restart_block.fn = do_no_restart_syscall;
  
  	if (!access_ok(VERIFY_READ, uc, sizeof(*uc)))
  		goto badframe;
  
  	if (__copy_from_user(&set, &uc->uc_sigmask, sizeof(set)))
  		goto badframe;
  	set_current_blocked(&set);
  #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
  	if (__get_user(msr, &uc->uc_mcontext.gp_regs[PT_MSR]))
  		goto badframe;
  	if (MSR_TM_ACTIVE(msr)) {
  		/* We recheckpoint on return. */
  		struct ucontext __user *uc_transact;
  		if (__get_user(uc_transact, &uc->uc_link))
  			goto badframe;
  		if (restore_tm_sigcontexts(regs, &uc->uc_mcontext,
  					   &uc_transact->uc_mcontext))
  			goto badframe;
  	}
  	else
  	/* Fall through, for non-TM restore */
  #endif
  	if (restore_sigcontext(regs, NULL, 1, &uc->uc_mcontext))
  		goto badframe;
  
  	if (restore_altstack(&uc->uc_stack))
  		goto badframe;
  
  	set_thread_flag(TIF_RESTOREALL);
  	return 0;
  
  badframe:
  #if DEBUG_SIG
  	printk("badframe in sys_rt_sigreturn, regs=%p uc=%p &uc->uc_mcontext=%p\n",
  	       regs, uc, &uc->uc_mcontext);
  #endif
  	if (show_unhandled_signals)
  		printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32,
  				   current->comm, current->pid, "rt_sigreturn",
  				   (long)uc, regs->nip, regs->link);
  
  	force_sig(SIGSEGV, current);
  	return 0;
  }
  
  int handle_rt_signal64(int signr, struct k_sigaction *ka, siginfo_t *info,
  		sigset_t *set, struct pt_regs *regs)
  {
  	struct rt_sigframe __user *frame;
  	unsigned long newsp = 0;
  	long err = 0;
  
  	frame = get_sigframe(ka, get_tm_stackpointer(regs), sizeof(*frame), 0);
  	if (unlikely(frame == NULL))
  		goto badframe;
  
  	err |= __put_user(&frame->info, &frame->pinfo);
  	err |= __put_user(&frame->uc, &frame->puc);
  	err |= copy_siginfo_to_user(&frame->info, info);
  	if (err)
  		goto badframe;
  
  	/* Create the ucontext.  */
  	err |= __put_user(0, &frame->uc.uc_flags);
  	err |= __save_altstack(&frame->uc.uc_stack, regs->gpr[1]);
  #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
  	if (MSR_TM_ACTIVE(regs->msr)) {
  		/* The ucontext_t passed to userland points to the second
  		 * ucontext_t (for transactional state) with its uc_link ptr.
  		 */
  		err |= __put_user(&frame->uc_transact, &frame->uc.uc_link);
  		err |= setup_tm_sigcontexts(&frame->uc.uc_mcontext,
  					    &frame->uc_transact.uc_mcontext,
  					    regs, signr,
  					    NULL,
  					    (unsigned long)ka->sa.sa_handler);
  	} else
  #endif
  	{
  		err |= __put_user(0, &frame->uc.uc_link);
  		err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, signr,
  					NULL, (unsigned long)ka->sa.sa_handler,
  					1);
  	}
  	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
  	if (err)
  		goto badframe;
  
  	/* Make sure signal handler doesn't get spurious FP exceptions */
  	current->thread.fp_state.fpscr = 0;
  #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
  	/* Remove TM bits from thread's MSR.  The MSR in the sigcontext
  	 * just indicates to userland that we were doing a transaction, but we
  	 * don't want to return in transactional state:
  	 */
  	regs->msr &= ~MSR_TS_MASK;
  #endif
  
  	/* Set up to return from userspace. */
  	if (vdso64_rt_sigtramp && current->mm->context.vdso_base) {
  		regs->link = current->mm->context.vdso_base + vdso64_rt_sigtramp;
  	} else {
  		err |= setup_trampoline(__NR_rt_sigreturn, &frame->tramp[0]);
  		if (err)
  			goto badframe;
  		regs->link = (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->nip = (unsigned long) ka->sa.sa_handler;
  		regs->gpr[12] = regs->nip;
  	} 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.
  		 */
  		func_descr_t __user *funct_desc_ptr =
  			(func_descr_t __user *) ka->sa.sa_handler;
  
  		err |= get_user(regs->nip, &funct_desc_ptr->entry);
  		err |= get_user(regs->gpr[2], &funct_desc_ptr->toc);
  	}
  
  	/* enter the signal handler in native-endian mode */
  	regs->msr &= ~MSR_LE;
  	regs->msr |= (MSR_KERNEL & MSR_LE);
  	regs->gpr[1] = newsp;
  	regs->gpr[3] = signr;
  	regs->result = 0;
  	if (ka->sa.sa_flags & SA_SIGINFO) {
  		err |= get_user(regs->gpr[4], (unsigned long __user *)&frame->pinfo);
  		err |= get_user(regs->gpr[5], (unsigned long __user *)&frame->puc);
  		regs->gpr[6] = (unsigned long) frame;
  	} else {
  		regs->gpr[4] = (unsigned long)&frame->uc.uc_mcontext;
  	}
  	if (err)
  		goto badframe;
  
  	return 1;
  
  badframe:
  #if DEBUG_SIG
  	printk("badframe in setup_rt_frame, regs=%p frame=%p newsp=%lx\n",
  	       regs, frame, newsp);
  #endif
  	if (show_unhandled_signals)
  		printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32,
  				   current->comm, current->pid, "setup_rt_frame",
  				   (long)frame, regs->nip, regs->link);
  
  	force_sigsegv(signr, current);
  	return 0;
  }
  