Merge samba.org:/home/paulus/kernel/linux-2.5

into samba.org:/home/paulus/kernel/for-linus-ppc

11 files changed, 531 insertions, 344 deletions

diff --git a/arch/ppc/kernel/align.c b/arch/ppc/kernel/align.c
index ed5a13ca643f..d942c318675d 100644
--- a/arch/ppc/kernel/align.c
+++ b/arch/ppc/kernel/align.c
@@ -21,11 +21,11 @@ struct aligninfo {
 	unsigned char flags;
 };
 
-#if defined(CONFIG_4xx)
+#if defined(CONFIG_4xx) || defined(CONFIG_POWER4)
 #define	OPCD(inst)	(((inst) & 0xFC000000) >> 26)
 #define	RS(inst)	(((inst) & 0x03E00000) >> 21)
 #define	RA(inst)	(((inst) & 0x001F0000) >> 16)
-#define	IS_DFORM(code)	((code) >= 32 && (code) <= 55)
+#define	IS_XFORM(code)	((code) == 31)
 #endif
 
 #define INVALID	{ 0, 0 }
@@ -61,9 +61,9 @@ static struct aligninfo aligninfo[128] = {
 	{ 4, ST+F+S },		/* 00 0 1010: stfs */
 	{ 8, ST+F },		/* 00 0 1011: stfd */
 	INVALID,		/* 00 0 1100 */
-	INVALID,		/* 00 0 1101 */
+	INVALID,		/* 00 0 1101: ld/ldu/lwa */
 	INVALID,		/* 00 0 1110 */
-	INVALID,		/* 00 0 1111 */
+	INVALID,		/* 00 0 1111: std/stdu */
 	{ 4, LD+U },		/* 00 1 0000: lwzu */
 	INVALID,		/* 00 1 0001 */
 	{ 4, ST+U },		/* 00 1 0010: stwu */
@@ -80,12 +80,12 @@ static struct aligninfo aligninfo[128] = {
 	INVALID,		/* 00 1 1101 */
 	INVALID,		/* 00 1 1110 */
 	INVALID,		/* 00 1 1111 */
-	INVALID,		/* 01 0 0000 */
+	INVALID,		/* 01 0 0000: ldx */
 	INVALID,		/* 01 0 0001 */
-	INVALID,		/* 01 0 0010 */
+	INVALID,		/* 01 0 0010: stdx */
 	INVALID,		/* 01 0 0011 */
 	INVALID,		/* 01 0 0100 */
-	INVALID,		/* 01 0 0101: lwax?? */
+	INVALID,		/* 01 0 0101: lwax */
 	INVALID,		/* 01 0 0110 */
 	INVALID,		/* 01 0 0111 */
 	{ 0, LD+HARD },		/* 01 0 1000: lswx */
@@ -96,12 +96,12 @@ static struct aligninfo aligninfo[128] = {
 	INVALID,		/* 01 0 1101 */
 	INVALID,		/* 01 0 1110 */
 	INVALID,		/* 01 0 1111 */
-	INVALID,		/* 01 1 0000 */
+	INVALID,		/* 01 1 0000: ldux */
 	INVALID,		/* 01 1 0001 */
-	INVALID,		/* 01 1 0010 */
+	INVALID,		/* 01 1 0010: stdux */
 	INVALID,		/* 01 1 0011 */
 	INVALID,		/* 01 1 0100 */
-	INVALID,		/* 01 1 0101: lwaux?? */
+	INVALID,		/* 01 1 0101: lwaux */
 	INVALID,		/* 01 1 0110 */
 	INVALID,		/* 01 1 0111 */
 	INVALID,		/* 01 1 1000 */
@@ -157,9 +157,9 @@ static struct aligninfo aligninfo[128] = {
 	{ 4, ST+F+S },		/* 11 0 1010: stfsx */
 	{ 8, ST+F },		/* 11 0 1011: stfdx */
 	INVALID,		/* 11 0 1100 */
-	INVALID,		/* 11 0 1101 */
+	INVALID,		/* 11 0 1101: lmd */
 	INVALID,		/* 11 0 1110 */
-	INVALID,		/* 11 0 1111 */
+	INVALID,		/* 11 0 1111: stmd */
 	{ 4, LD+U },		/* 11 1 0000: lwzux */
 	INVALID,		/* 11 1 0001 */
 	{ 4, ST+U },		/* 11 1 0010: stwux */
@@ -184,7 +184,7 @@ int
 fix_alignment(struct pt_regs *regs)
 {
 	int instr, nb, flags;
-#if defined(CONFIG_4xx)
+#if defined(CONFIG_4xx) || defined(CONFIG_POWER4)
 	int opcode, f1, f2, f3;
 #endif
 	int i, t;
@@ -199,9 +199,11 @@ fix_alignment(struct pt_regs *regs)
 
 	CHECK_FULL_REGS(regs);
 
-#if defined(CONFIG_4xx)
+#if defined(CONFIG_4xx) || defined(CONFIG_POWER4)
 	/* The 4xx-family processors have no DSISR register,
 	 * so we emulate it.
+	 * The POWER4 has a DSISR register but doesn't set it on
+	 * an alignment fault.  -- paulus
 	 */
 
 	instr = *((unsigned int *)regs->nip);
@@ -209,7 +211,7 @@ fix_alignment(struct pt_regs *regs)
 	reg = RS(instr);
 	areg = RA(instr);
 
-	if (IS_DFORM(opcode)) {
+	if (!IS_XFORM(opcode)) {
 		f1 = 0;
 		f2 = (instr & 0x04000000) >> 26;
 		f3 = (instr & 0x78000000) >> 27;
diff --git a/arch/ppc/kernel/asm-offsets.c b/arch/ppc/kernel/asm-offsets.c
index 6e6f78e4e3a0..e41af4ff4dc6 100644
--- a/arch/ppc/kernel/asm-offsets.c
+++ b/arch/ppc/kernel/asm-offsets.c
@@ -52,6 +52,7 @@ main(void)
 	DEFINE(THREAD_VR0, offsetof(struct thread_struct, vr[0]));
 	DEFINE(THREAD_VRSAVE, offsetof(struct thread_struct, vrsave));
 	DEFINE(THREAD_VSCR, offsetof(struct thread_struct, vscr));
+	DEFINE(THREAD_USED_VR, offsetof(struct thread_struct, used_vr));
 #endif /* CONFIG_ALTIVEC */
 	/* Interrupt register frame */
 	DEFINE(STACK_FRAME_OVERHEAD, STACK_FRAME_OVERHEAD);
@@ -101,7 +102,7 @@ main(void)
 	DEFINE(_XER, STACK_FRAME_OVERHEAD+offsetof(struct pt_regs, xer));
 	DEFINE(_DAR, STACK_FRAME_OVERHEAD+offsetof(struct pt_regs, dar));
 	DEFINE(_DSISR, STACK_FRAME_OVERHEAD+offsetof(struct pt_regs, dsisr));
-	/* The PowerPC 400-class processors have neither the DAR nor the DSISR
+	/* The PowerPC 400-class & Book-E processors have neither the DAR nor the DSISR
 	 * SPRs. Hence, we overload them to hold the similar DEAR and ESR SPRs
 	 * for such processors.  For critical interrupts we use them to
 	 * hold SRR0 and SRR1.
diff --git a/arch/ppc/kernel/head.S b/arch/ppc/kernel/head.S
index 0311ae117dee..af68a4ee38d8 100644
--- a/arch/ppc/kernel/head.S
+++ b/arch/ppc/kernel/head.S
@@ -915,7 +915,9 @@ load_up_altivec:
 	/* enable use of AltiVec after return */
 	oris	r9,r9,MSR_VEC@h
 	mfspr	r5,SPRG3		/* current task's THREAD (phys) */
+	li	r4,1
 	li	r10,THREAD_VSCR
+	stw	r4,THREAD_USED_VR(r5)
 	lvx	vr0,r10,r5
 	mtvscr	vr0
 	REST_32VR(0,r10,r5)
diff --git a/arch/ppc/kernel/misc.S b/arch/ppc/kernel/misc.S
index a41d10ee1614..b5f86a6d3267 100644
--- a/arch/ppc/kernel/misc.S
+++ b/arch/ppc/kernel/misc.S
@@ -1379,7 +1379,7 @@ _GLOBAL(sys_call_table)
 	.long sys_clock_gettime
 	.long sys_clock_getres
 	.long sys_clock_nanosleep
-	.long sys_ni_syscall	/* reserved for swapcontext */
+	.long sys_swapcontext
 	.long sys_tgkill	/* 250 */
 	.long sys_utimes
 	.long sys_statfs64
diff --git a/arch/ppc/kernel/process.c b/arch/ppc/kernel/process.c
index f0a608eb1a6e..82e09cc776bc 100644
--- a/arch/ppc/kernel/process.c
+++ b/arch/ppc/kernel/process.c
@@ -415,6 +415,7 @@ void start_thread(struct pt_regs *regs, unsigned long nip, unsigned long sp)
 	memset(current->thread.vr, 0, sizeof(current->thread.vr));
 	memset(&current->thread.vscr, 0, sizeof(current->thread.vscr));
 	current->thread.vrsave = 0;
+	current->thread.used_vr = 0;
 #endif /* CONFIG_ALTIVEC */
 }
 
diff --git a/arch/ppc/kernel/signal.c b/arch/ppc/kernel/signal.c
index 41efaef2153a..c737078db5b0 100644
--- a/arch/ppc/kernel/signal.c
+++ b/arch/ppc/kernel/signal.c
@@ -41,18 +41,6 @@ extern void sigreturn_exit(struct pt_regs *);
 
 #define GP_REGS_SIZE	min(sizeof(elf_gregset_t), sizeof(struct pt_regs))
 
-/* 
- * These are the flags in the MSR that the user is allowed to change
- * by modifying the saved value of the MSR on the stack.  SE and BE
- * should not be in this list since gdb may want to change these.  I.e,
- * you should be able to step out of a signal handler to see what
- * instruction executes next after the signal handler completes.
- * Alternately, if you stepped into a signal handler, you should be
- * able to continue 'til the next breakpoint from within the signal
- * handler, even if the handler returns.
- */
-#define MSR_USERCHANGE	(MSR_FE0 | MSR_FE1)
-
 int do_signal(sigset_t *oldset, struct pt_regs *regs);
 
 /*
@@ -72,8 +60,8 @@ sys_sigsuspend(old_sigset_t mask, int p2, int p3, int p4, int p6, int p7,
 	spin_unlock_irq(&current->sighand->siglock);
 
 	regs->result = -EINTR;
-	regs->ccr |= 0x10000000;
 	regs->gpr[3] = EINTR;
+	regs->ccr |= 0x10000000;
 	while (1) {
 		current->state = TASK_INTERRUPTIBLE;
 		schedule();
@@ -103,8 +91,8 @@ sys_rt_sigsuspend(sigset_t __user *unewset, size_t sigsetsize, int p3, int p4,
 	spin_unlock_irq(&current->sighand->siglock);
 
 	regs->result = -EINTR;
-	regs->ccr |= 0x10000000;
 	regs->gpr[3] = EINTR;
+	regs->ccr |= 0x10000000;
 	while (1) {
 		current->state = TASK_INTERRUPTIBLE;
 		schedule();
@@ -164,305 +152,389 @@ sys_sigaction(int sig, const struct old_sigaction __user *act,
  *
  */
 struct sigregs {
-	elf_gregset_t	gp_regs;
-	double		fp_regs[ELF_NFPREG];
-	unsigned long	tramp[2];
+	struct mcontext	mctx;		/* all the register values */
 	/* Programs using the rs6000/xcoff abi can save up to 19 gp regs
 	   and 18 fp regs below sp before decrementing it. */
 	int		abigap[56];
 };
 
-struct rt_sigframe
-{
-	unsigned long	_unused[2];
-	struct siginfo *pinfo;
-	void *puc;
-	struct siginfo info;
-	struct ucontext uc;
-};
-
+/* We use the mc_pad field for the signal return trampoline. */
+#define tramp	mc_pad
 
 /*
  *  When we have rt signals to deliver, we set up on the
  *  user stack, going down from the original stack pointer:
- *	   a sigregs struct
- *	   one rt_sigframe struct (siginfo + ucontext)
- *	   a gap of __SIGNAL_FRAMESIZE bytes
+ *	one rt_sigframe struct (siginfo + ucontext + ABI gap)
+ *	a gap of __SIGNAL_FRAMESIZE+16 bytes
+ *  (the +16 is to get the siginfo and ucontext in the same
+ *  positions as in older kernels).
  *
  *  Each of these things must be a multiple of 16 bytes in size.
  *
  */
-int sys_rt_sigreturn(int r3, int r4, int r5, int r6, int r7, int r8,
-		     struct pt_regs *regs)
+struct rt_sigframe
 {
-	struct rt_sigframe __user *rt_sf;
-	struct sigcontext sigctx;
-	struct sigregs __user *sr;
-	elf_gregset_t saved_regs;  /* an array of ELF_NGREG unsigned longs */
-	sigset_t set;
-	stack_t st;
+	struct siginfo info;
+	struct ucontext uc;
+	/* Programs using the rs6000/xcoff abi can save up to 19 gp regs
+	   and 18 fp regs below sp before decrementing it. */
+	int		abigap[56];
+};
 
-	rt_sf = (struct rt_sigframe __user *)(regs->gpr[1] + __SIGNAL_FRAMESIZE);
-	if (copy_from_user(&sigctx, &rt_sf->uc.uc_mcontext, sizeof(sigctx))
-	    || copy_from_user(&set, &rt_sf->uc.uc_sigmask, sizeof(set))
-	    || copy_from_user(&st, &rt_sf->uc.uc_stack, sizeof(st)))
-		goto badframe;
-	sigdelsetmask(&set, ~_BLOCKABLE);
-	spin_lock_irq(&current->sighand->siglock);
-	current->blocked = set;
-	recalc_sigpending();
-	spin_unlock_irq(&current->sighand->siglock);
+/*
+ * Save the current user registers on the user stack.
+ * We only save the altivec registers if the process has used
+ * altivec instructions at some point.
+ */
+static int
+save_user_regs(struct pt_regs *regs, struct mcontext *frame, int sigret)
+{
+	/* save general and floating-point registers */
+	CHECK_FULL_REGS(regs);
 	if (regs->msr & MSR_FP)
 		giveup_fpu(current);
+	if (__copy_to_user(&frame->mc_gregs, regs, GP_REGS_SIZE)
+	    || __copy_to_user(&frame->mc_fregs, current->thread.fpr,
+			      ELF_NFPREG * sizeof(double)))
+		return 1;
 
-	/* restore registers -
-	 * sigctx is initialized to point to the 
-	 * preamble frame (where registers are stored) 
-	 * see handle_signal()
+	current->thread.fpscr = 0;	/* turn off all fp exceptions */
+
+#ifdef CONFIG_ALTIVEC
+	/* save altivec registers */
+	if (current->thread.used_vr) {
+		if (regs->msr & MSR_VEC)
+			giveup_altivec(current);
+		if (__copy_to_user(&frame->mc_vregs, current->thread.vr,
+				   ELF_NVRREG * sizeof(vector128)))
+			return 1;
+		/* set MSR_VEC in the saved MSR value to indicate that
+		   frame->mc_vregs contains valid data */
+		if (__put_user(regs->msr | MSR_VEC, &frame->mc_gregs[PT_MSR]))
+			return 1;
+	}
+	/* else assert((regs->msr & MSR_VEC) == 0) */
+
+	/* We always copy to/from vrsave, it's 0 if we don't have or don't
+	 * use altivec. Since VSCR only contains 32 bits saved in the least
+	 * significant bits of a vector, we "cheat" and stuff VRSAVE in the
+	 * most significant bits of that same vector. --BenH
 	 */
-	sr = (struct sigregs __user *) sigctx.regs;
-	if (copy_from_user(saved_regs, &sr->gp_regs, sizeof(sr->gp_regs)))
-		goto badframe;
-	saved_regs[PT_MSR] = (regs->msr & ~MSR_USERCHANGE)
-		| (saved_regs[PT_MSR] & MSR_USERCHANGE);
-	memcpy(regs, saved_regs, GP_REGS_SIZE);
-	if (copy_from_user(current->thread.fpr, &sr->fp_regs,
-			   sizeof(sr->fp_regs)))
-		goto badframe;
+	if (__put_user(current->thread.vrsave, (u32 *)&frame->mc_vregs[32]))
+		return 1;
+#endif /* CONFIG_ALTIVEC */
+
+	if (sigret) {
+		/* Set up the sigreturn trampoline: li r0,sigret; sc */
+		if (__put_user(0x38000000UL + sigret, &frame->tramp[0])
+		    || __put_user(0x44000002UL, &frame->tramp[1]))
+			return 1;
+		flush_icache_range((unsigned long) &frame->tramp[0],
+				   (unsigned long) &frame->tramp[2]);
+	}
 
-	sigreturn_exit(regs);		/* doesn't return here */
 	return 0;
+}
 
-badframe:
-	do_exit(SIGSEGV);
+/*
+ * Restore the current user register values from the user stack,
+ * (except for MSR).
+ */
+static int
+restore_user_regs(struct pt_regs *regs, struct mcontext __user *sr)
+{
+#ifdef CONFIG_ALTIVEC
+	unsigned long msr;
+#endif
+
+	/* copy up to but not including MSR */
+	if (__copy_from_user(regs, &sr->mc_gregs, PT_MSR * sizeof(elf_greg_t)))
+		return 1;
+	/* copy from orig_r3 (the word after the MSR) up to the end */
+	if (__copy_from_user(&regs->orig_gpr3, &sr->mc_gregs[PT_ORIG_R3],
+			     GP_REGS_SIZE - PT_ORIG_R3 * sizeof(elf_greg_t)))
+		return 1;
+
+	/* force the process to reload the FP registers from
+	   current->thread when it next does FP instructions */
+	regs->msr &= ~MSR_FP;
+	if (__copy_from_user(current->thread.fpr, &sr->mc_fregs,
+			     sizeof(sr->mc_fregs)))
+		return 1;
+
+#ifdef CONFIG_ALTIVEC
+	/* force the process to reload the altivec registers from
+	   current->thread when it next does altivec instructions */
+	regs->msr &= ~MSR_VEC;
+	if (!__get_user(msr, &sr->mc_gregs[PT_MSR]) && (msr & MSR_VEC) != 0) {
+		/* restore altivec registers from the stack */
+		if (__copy_from_user(current->thread.vr, &sr->mc_vregs,
+				     sizeof(sr->mc_vregs)))
+			return 1;
+	} else if (current->thread.used_vr)
+		memset(&current->thread.vr, 0, sizeof(current->thread.vr));
+
+	/* Always get VRSAVE back */
+	if (__get_user(current->thread.vrsave, (u32 *)&sr->mc_vregs[32]))
+		return 1;
+#endif /* CONFIG_ALTIVEC */
+
+	return 0;
 }
 
+/*
+ * Restore the user process's signal mask
+ */
 static void
-setup_rt_frame(struct pt_regs *regs, struct sigregs __user *frame,
-	       signed long newsp)
+restore_sigmask(sigset_t *set)
 {
-	struct rt_sigframe __user *rt_sf = (struct rt_sigframe __user *) newsp;
+	sigdelsetmask(set, ~_BLOCKABLE);
+	spin_lock_irq(&current->sighand->siglock);
+	current->blocked = *set;
+	recalc_sigpending();
+	spin_unlock_irq(&current->sighand->siglock);
+}
 
-	/* Set up preamble frame */
-	if (verify_area(VERIFY_WRITE, frame, sizeof(*frame)))
+/*
+ * Set up a signal frame for a "real-time" signal handler
+ * (one which gets siginfo).
+ */
+static void
+handle_rt_signal(unsigned long sig, struct k_sigaction *ka,
+		 siginfo_t *info, sigset_t *oldset, struct pt_regs * regs,
+		 unsigned long newsp)
+{
+	struct rt_sigframe __user *rt_sf;
+	struct mcontext __user *frame;
+	unsigned long origsp = newsp;
+
+	/* Set up Signal Frame */
+	/* Put a Real Time Context onto stack */
+	newsp -= sizeof(*rt_sf);
+	rt_sf = (struct rt_sigframe __user *) newsp;
+
+	/* create a stack frame for the caller of the handler */
+	newsp -= __SIGNAL_FRAMESIZE + 16;
+
+	if (verify_area(VERIFY_WRITE, (void __user *) newsp, origsp - newsp))
 		goto badframe;
-	CHECK_FULL_REGS(regs);
-	if (regs->msr & MSR_FP)
-		giveup_fpu(current);
-	if (__copy_to_user(&frame->gp_regs, regs, GP_REGS_SIZE)
-	    || __copy_to_user(&frame->fp_regs, current->thread.fpr,
-			      ELF_NFPREG * sizeof(double))
-	/* Set up to return from user space.
-	   It calls the sc exception at offset 0x9999 
-	   for sys_rt_sigreturn().
-	*/
-	    || __put_user(0x38000000UL + __NR_rt_sigreturn, &frame->tramp[0])
-	    || __put_user(0x44000002UL, &frame->tramp[1]))	/* sc */
+
+	/* Put the siginfo & fill in most of the ucontext */
+	if (copy_siginfo_to_user(&rt_sf->info, info)
+	    || __put_user(0, &rt_sf->uc.uc_flags)
+	    || __put_user(0, &rt_sf->uc.uc_link)
+	    || __put_user(current->sas_ss_sp, &rt_sf->uc.uc_stack.ss_sp)
+	    || __put_user(sas_ss_flags(regs->gpr[1]), 
+			  &rt_sf->uc.uc_stack.ss_flags)
+	    || __put_user(current->sas_ss_size, &rt_sf->uc.uc_stack.ss_size)
+	    || __put_user(&rt_sf->uc.uc_mcontext, &rt_sf->uc.uc_regs)
+	    || __copy_to_user(&rt_sf->uc.uc_oldsigmask, oldset, sizeof(*oldset))
+	    || __copy_to_user(&rt_sf->uc.uc_sigmask, oldset, sizeof(*oldset)))
 		goto badframe;
-	flush_icache_range((unsigned long) &frame->tramp[0],
-			   (unsigned long) &frame->tramp[2]);
-	current->thread.fpscr = 0;	/* turn off all fp exceptions */
 
-	/* Retrieve rt_sigframe from stack and
-	   set up registers for signal handler
-	*/
-	newsp -= __SIGNAL_FRAMESIZE;
-	if (put_user(regs->gpr[1], (unsigned long __user *)newsp)
-	    || get_user(regs->nip, &rt_sf->uc.uc_mcontext.handler)
-	    || get_user(regs->gpr[3], &rt_sf->uc.uc_mcontext.signal)
-	    || get_user(regs->gpr[4], (unsigned long __user *)&rt_sf->pinfo)
-	    || get_user(regs->gpr[5], (unsigned long __user *)&rt_sf->puc))
+	/* Save user registers on the stack */
+	frame = &rt_sf->uc.uc_mcontext;
+	if (save_user_regs(regs, frame, __NR_rt_sigreturn))
 		goto badframe;
 
+	if (put_user(regs->gpr[1], (unsigned long __user *)newsp))
+		goto badframe;
 	regs->gpr[1] = newsp;
+	regs->gpr[3] = sig;
+	regs->gpr[4] = (unsigned long) &rt_sf->info;
+	regs->gpr[5] = (unsigned long) &rt_sf->uc;
 	regs->gpr[6] = (unsigned long) rt_sf;
+	regs->nip = (unsigned long) ka->sa.sa_handler;
 	regs->link = (unsigned long) frame->tramp;
+	regs->trap = 0;
 
 	return;
 
 badframe:
 #if DEBUG_SIG
-	printk("badframe in setup_rt_frame, regs=%p frame=%p newsp=%lx\n",
+	printk("badframe in handle_rt_signal, regs=%p frame=%p newsp=%lx\n",
 	       regs, frame, newsp);
 #endif
-	do_exit(SIGSEGV);
+	if (sig == SIGSEGV)
+		ka->sa.sa_handler = SIG_DFL;
+	force_sig(SIGSEGV, current);
 }
 
-/*
- * Do a signal return; undo the signal stack.
- */
-int sys_sigreturn(int r3, int r4, int r5, int r6, int r7, int r8,
-		  struct pt_regs *regs)
+static int do_setcontext(struct ucontext __user *ucp, struct pt_regs *regs)
 {
-	struct sigcontext __user *sc;
-	struct sigcontext sigctx;
-	struct sigregs __user *sr;
-	elf_gregset_t saved_regs;  /* an array of ELF_NGREG unsigned longs */
 	sigset_t set;
 
-	sc = (struct sigcontext __user *)(regs->gpr[1] + __SIGNAL_FRAMESIZE);
-	if (copy_from_user(&sigctx, sc, sizeof(sigctx)))
-		goto badframe;
+	if (__copy_from_user(&set, &ucp->uc_sigmask, sizeof(set)))
+		return -EFAULT;
+	restore_sigmask(&set);
 
-	set.sig[0] = sigctx.oldmask;
-#if _NSIG_WORDS > 1
-	set.sig[1] = sigctx._unused[3];
-#endif
-	sigdelsetmask(&set, ~_BLOCKABLE);
-	spin_lock_irq(&current->sighand->siglock);
-	current->blocked = set;
-	recalc_sigpending();
-	spin_unlock_irq(&current->sighand->siglock);
-	if (regs->msr & MSR_FP )
-		giveup_fpu(current);
+	if (restore_user_regs(regs, &ucp->uc_mcontext))
+		return -EFAULT;
 
-	/* restore registers */
-	sr = (struct sigregs __user *) sigctx.regs;
-	if (copy_from_user(saved_regs, &sr->gp_regs, sizeof(sr->gp_regs)))
-		goto badframe;
-	saved_regs[PT_MSR] = (regs->msr & ~MSR_USERCHANGE)
-		| (saved_regs[PT_MSR] & MSR_USERCHANGE);
-	memcpy(regs, saved_regs, GP_REGS_SIZE);
+	return 0;
+}
 
-	if (copy_from_user(current->thread.fpr, &sr->fp_regs,
-			   sizeof(sr->fp_regs)))
-		goto badframe;
+int sys_swapcontext(struct ucontext __user *old_ctx,
+		    struct ucontext __user *new_ctx,
+		    int r5, int r6, int r7, int r8, struct pt_regs *regs)
+{
+	unsigned char tmp;
+
+	if (old_ctx != NULL) {
+		if (verify_area(VERIFY_WRITE, old_ctx, sizeof(*old_ctx))
+		    || save_user_regs(regs, &old_ctx->uc_mcontext, 0)
+		    || __copy_to_user(&old_ctx->uc_sigmask,
+				      &current->blocked, sizeof(sigset_t))
+		    /* the next 2 things aren't strictly necessary */
+		    || __copy_to_user(&old_ctx->uc_oldsigmask,
+				      &current->blocked, sizeof(sigset_t))
+		    || __put_user(&old_ctx->uc_mcontext, &old_ctx->uc_regs))
+			return -EFAULT;
+	}
+	if (new_ctx == NULL)
+		return 0;
+	if (verify_area(VERIFY_READ, new_ctx, sizeof(*new_ctx))
+	    || __get_user(tmp, (u8 *) new_ctx)
+	    || __get_user(tmp, (u8 *) (new_ctx + 1) - 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 verify_area
+	 * 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 (do_setcontext(new_ctx, regs))
+		do_exit(SIGSEGV);
+	sigreturn_exit(regs);
+	/* doesn't actually return back to here */
+	return 0;
+}
+
+int sys_rt_sigreturn(int r3, int r4, int r5, int r6, int r7, int r8,
+		     struct pt_regs *regs)
+{
+	struct rt_sigframe __user *rt_sf;
+
+	rt_sf = (struct rt_sigframe __user *)
+		(regs->gpr[1] + __SIGNAL_FRAMESIZE + 16);
+	if (verify_area(VERIFY_READ, rt_sf, sizeof(struct rt_sigframe)))
+		goto bad;
+	if (do_setcontext(&rt_sf->uc, regs))
+		goto bad;
+
+	/*
+	 * It's not clear whether or why it is desirable to save the
+	 * sigaltstack setting on signal delivery and restore it on
+	 * signal return.  But other architectures do this and we have
+	 * always done it up until now so it is probably better not to
+	 * change it.  -- paulus
+	 */
+	do_sigaltstack(&rt_sf->uc.uc_stack, NULL, regs->gpr[1]);
 
 	sigreturn_exit(regs);		/* doesn't return here */
 	return 0;
 
-badframe:
-	do_exit(SIGSEGV);
-}	
+ bad:
+	force_sig(SIGSEGV, current);
+	return 0;
+}
 
 /*
- * Set up a signal frame.
+ * OK, we're invoking a handler
  */
 static void
-setup_frame(struct pt_regs *regs, struct sigregs __user *frame,
-	    unsigned long newsp)
+handle_signal(unsigned long sig, struct k_sigaction *ka,
+	      siginfo_t *info, sigset_t *oldset, struct pt_regs * regs,
+	      unsigned long newsp)
 {
-	struct sigcontext __user *sc = (struct sigcontext __user *) newsp;
+	struct sigcontext __user *sc;
+	struct sigregs __user *frame;
+	unsigned long origsp = newsp;
 
-	if (verify_area(VERIFY_WRITE, frame, sizeof(*frame)))
+	/* Set up Signal Frame */
+	newsp -= sizeof(struct sigregs);
+	frame = (struct sigregs __user *) newsp;
+
+	/* Put a sigcontext on the stack */
+	newsp -= sizeof(*sc);
+	sc = (struct sigcontext __user *) newsp;
+
+	/* create a stack frame for the caller of the handler */
+	newsp -= __SIGNAL_FRAMESIZE;
+
+	if (verify_area(VERIFY_WRITE, (void *) newsp, origsp - newsp))
 		goto badframe;
-	CHECK_FULL_REGS(regs);
-	if (regs->msr & MSR_FP)
-		giveup_fpu(current);
-	if (__copy_to_user(&frame->gp_regs, regs, GP_REGS_SIZE)
-	    || __copy_to_user(&frame->fp_regs, current->thread.fpr,
-			      ELF_NFPREG * sizeof(double))
-	    || __put_user(0x38000000UL + __NR_sigreturn, &frame->tramp[0])
-	    || __put_user(0x44000002UL, &frame->tramp[1]))   /* sc */
+
+#if _NSIG != 64
+#error "Please adjust handle_signal()"
+#endif
+	if (__put_user((unsigned long) ka->sa.sa_handler, &sc->handler)
+	    || __put_user(oldset->sig[0], &sc->oldmask)
+	    || __put_user(oldset->sig[1], &sc->_unused[3])
+	    || __put_user((struct pt_regs *)frame, &sc->regs)
+	    || __put_user(sig, &sc->signal))
 		goto badframe;
-	flush_icache_range((unsigned long) &frame->tramp[0],
-			   (unsigned long) &frame->tramp[2]);
-	current->thread.fpscr = 0;	/* turn off all fp exceptions */
 
-	newsp -= __SIGNAL_FRAMESIZE;
-	if (put_user(regs->gpr[1], (unsigned long __user *)newsp)
-	    || get_user(regs->nip, &sc->handler)
-	    || get_user(regs->gpr[3], &sc->signal))
+	if (save_user_regs(regs, &frame->mctx, __NR_sigreturn))
+		goto badframe;
+
+	if (put_user(regs->gpr[1], (unsigned long *)newsp))
 		goto badframe;
 	regs->gpr[1] = newsp;
+	regs->gpr[3] = sig;
 	regs->gpr[4] = (unsigned long) sc;
-	regs->link = (unsigned long) frame->tramp;
+	regs->nip = (unsigned long) ka->sa.sa_handler;
+	regs->link = (unsigned long) frame->mctx.tramp;
+	regs->trap = 0;
 
 	return;
 
 badframe:
 #if DEBUG_SIG
-	printk("badframe in setup_frame, regs=%p frame=%p newsp=%lx\n",
-	       regs, frame, newsp);
+	printk("badframe in handle_signal, regs=%p frame=%lx newsp=%lx\n",
+	       regs, frame, *newspp);
 #endif
-	do_exit(SIGSEGV);
+	if (sig == SIGSEGV)
+		ka->sa.sa_handler = SIG_DFL;
+	force_sig(SIGSEGV, current);
 }
 
 /*
- * OK, we're invoking a handler
+ * Do a signal return; undo the signal stack.
  */
-static void
-handle_signal(unsigned long sig, siginfo_t *info, sigset_t *oldset,
-	struct pt_regs * regs, unsigned long *newspp, unsigned long frame)
+int sys_sigreturn(int r3, int r4, int r5, int r6, int r7, int r8,
+		  struct pt_regs *regs)
 {
 	struct sigcontext __user *sc;
-	struct rt_sigframe __user *rt_sf;
-	struct k_sigaction *ka = &current->sighand->action[sig-1];
-
-	if (TRAP(regs) == 0x0C00 /* System Call! */
-	    && ((int)regs->result == -ERESTARTNOHAND ||
-		(int)regs->result == -ERESTART_RESTARTBLOCK ||
-		((int)regs->result == -ERESTARTSYS &&
-		 !(ka->sa.sa_flags & SA_RESTART)))) {
-		if ((int)regs->result == -ERESTART_RESTARTBLOCK)
-			current_thread_info()->restart_block.fn
-				= do_no_restart_syscall;
-		regs->result = -EINTR;
-		regs->gpr[3] = EINTR;
-		regs->ccr |= 0x10000000;
-	}
+	struct sigcontext sigctx;
+	struct mcontext __user *sr;
+	sigset_t set;
 
-	/* Set up Signal Frame */
-	if (ka->sa.sa_flags & SA_SIGINFO) {
-		/* Put a Real Time Context onto stack */
-		*newspp -= sizeof(*rt_sf);
-		rt_sf = (struct rt_sigframe __user *) *newspp;
-		if (verify_area(VERIFY_WRITE, rt_sf, sizeof(*rt_sf)))
-			goto badframe;
-
-		if (__put_user((unsigned long) ka->sa.sa_handler, &rt_sf->uc.uc_mcontext.handler)
-		    || __put_user(&rt_sf->info, &rt_sf->pinfo)
-		    || __put_user(&rt_sf->uc, &rt_sf->puc)
-		    /* Put the siginfo */
-		    || copy_siginfo_to_user(&rt_sf->info, info)
-		    /* Create the ucontext */
-		    || __put_user(0, &rt_sf->uc.uc_flags)
-		    || __put_user(0, &rt_sf->uc.uc_link)
-		    || __put_user(current->sas_ss_sp, &rt_sf->uc.uc_stack.ss_sp)
-		    || __put_user(sas_ss_flags(regs->gpr[1]), 
-				  &rt_sf->uc.uc_stack.ss_flags)
-		    || __put_user(current->sas_ss_size, &rt_sf->uc.uc_stack.ss_size)
-		    || __copy_to_user(&rt_sf->uc.uc_sigmask, oldset, sizeof(*oldset))
-		    /* mcontext.regs points to preamble register frame */
-		    || __put_user((struct pt_regs *)frame, &rt_sf->uc.uc_mcontext.regs)
-		    || __put_user(sig, &rt_sf->uc.uc_mcontext.signal))
-			goto badframe;
-	} else {
-		/* Put a sigcontext on the stack */
-		*newspp -= sizeof(*sc);
-		sc = (struct sigcontext __user *) *newspp;
-		if (verify_area(VERIFY_WRITE, sc, sizeof(*sc)))
-			goto badframe;
-		
-		if (__put_user((unsigned long) ka->sa.sa_handler, &sc->handler)
-		    || __put_user(oldset->sig[0], &sc->oldmask)
-#if _NSIG_WORDS > 1
-		    || __put_user(oldset->sig[1], &sc->_unused[3])
-#endif
-		    || __put_user((struct pt_regs *)frame, &sc->regs)
-		    || __put_user(sig, &sc->signal))
-			goto badframe;
-	}
+	sc = (struct sigcontext __user *)(regs->gpr[1] + __SIGNAL_FRAMESIZE);
+	if (copy_from_user(&sigctx, sc, sizeof(sigctx)))
+		goto badframe;
 
-	if (ka->sa.sa_flags & SA_ONESHOT)
-		ka->sa.sa_handler = SIG_DFL;
+	set.sig[0] = sigctx.oldmask;
+	set.sig[1] = sigctx._unused[3];
+	restore_sigmask(&set);
 
-	if (!(ka->sa.sa_flags & SA_NODEFER)) {
-		spin_lock_irq(&current->sighand->siglock);
-		sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
-		sigaddset(&current->blocked,sig);
-		recalc_sigpending();
-		spin_unlock_irq(&current->sighand->siglock);
-	}
-	return;
+	sr = (struct mcontext *) sigctx.regs;
+	if (verify_area(VERIFY_READ, sr, sizeof(*sr))
+	    || restore_user_regs(regs, sr))
+		goto badframe;
+
+	sigreturn_exit(regs);		/* doesn't return */
+	return 0;
 
 badframe:
-#if DEBUG_SIG
-	printk("badframe in handle_signal, regs=%p frame=%lx newsp=%lx\n",
-	       regs, frame, *newspp);
-	printk("sc=%p sig=%d ka=%p info=%p oldset=%p\n", sc, sig, ka, info, oldset);
-#endif
-	do_exit(SIGSEGV);
+	force_sig(SIGSEGV, current);
+	return 0;
 }
 
 /*
@@ -475,7 +547,7 @@ int do_signal(sigset_t *oldset, struct pt_regs *regs)
 	siginfo_t info;
 	struct k_sigaction *ka;
 	unsigned long frame, newsp;
-	int signr;
+	int signr, ret;
 
 	if (!oldset)
 		oldset = &current->blocked;
@@ -483,40 +555,65 @@ int do_signal(sigset_t *oldset, struct pt_regs *regs)
 	newsp = frame = 0;
 
 	signr = get_signal_to_deliver(&info, regs, NULL);
-	if (signr > 0) {
-		ka = &current->sighand->action[signr-1];
-		if ( (ka->sa.sa_flags & SA_ONSTACK)
-		     && (! on_sig_stack(regs->gpr[1])))
-			newsp = (current->sas_ss_sp + current->sas_ss_size);
-		else
-			newsp = regs->gpr[1];
-		newsp = frame = newsp - sizeof(struct sigregs);
-
-		/* Whee!  Actually deliver the signal.  */
-		handle_signal(signr, &info, oldset, regs, &newsp, frame);
-	}
 
-	if (TRAP(regs) == 0x0C00) {	/* System Call! */
-		if ((int)regs->result == -ERESTARTNOHAND ||
-		    (int)regs->result == -ERESTARTSYS ||
-		    (int)regs->result == -ERESTARTNOINTR) {
-			regs->gpr[3] = regs->orig_gpr3;
+	ka = (signr == 0)? NULL: &current->sighand->action[signr-1];
+
+	if (TRAP(regs) == 0x0C00		/* System Call! */
+	    && regs->ccr & 0x10000000		/* error signalled */
+	    && ((ret = regs->gpr[3]) == ERESTARTSYS
+		|| ret == ERESTARTNOHAND || ret == ERESTARTNOINTR
+		|| ret == ERESTART_RESTARTBLOCK)) {
+
+		if (signr > 0
+		    && (ret == ERESTARTNOHAND || ret == ERESTART_RESTARTBLOCK
+			|| (ret == ERESTARTSYS
+			    && !(ka->sa.sa_flags & SA_RESTART)))) {
+			/* make the system call return an EINTR error */
+			regs->result = -EINTR;
+			regs->gpr[3] = EINTR;
+			/* note that the cr0.SO bit is already set */
+			/* clear any restart function that was set */
+			if (ret == ERESTART_RESTARTBLOCK)
+				current_thread_info()->restart_block.fn
+					= do_no_restart_syscall;
+		} else {
 			regs->nip -= 4;	/* Back up & retry system call */
 			regs->result = 0;
-		} else if ((int)regs->result == -ERESTART_RESTARTBLOCK) {
-			regs->gpr[0] = __NR_restart_syscall;
-			regs->nip -= 4;
-			regs->result = 0;
+			regs->trap = 0;
+			if (ret == ERESTART_RESTARTBLOCK)
+				regs->gpr[0] = __NR_restart_syscall;
+			else
+				regs->gpr[3] = regs->orig_gpr3;
 		}
 	}
 
-	if (newsp == frame)
+	if (signr == 0)
 		return 0;		/* no signals delivered */
 
+	if ((ka->sa.sa_flags & SA_ONSTACK) && current->sas_ss_size
+	    && !on_sig_stack(regs->gpr[1]))
+		newsp = current->sas_ss_sp + current->sas_ss_size;
+	else
+		newsp = regs->gpr[1];
+	newsp &= ~0xfUL;
+
+	/* Whee!  Actually deliver the signal.  */
 	if (ka->sa.sa_flags & SA_SIGINFO)
-		setup_rt_frame(regs, (struct sigregs __user *) frame, newsp);
+		handle_rt_signal(signr, ka, &info, oldset, regs, newsp);
 	else
-		setup_frame(regs, (struct sigregs __user *) frame, newsp);
+		handle_signal(signr, ka, &info, oldset, regs, newsp);
+
+	if (ka->sa.sa_flags & SA_ONESHOT)
+		ka->sa.sa_handler = SIG_DFL;
+
+	if (!(ka->sa.sa_flags & SA_NODEFER)) {
+		spin_lock_irq(&current->sighand->siglock);
+		sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
+		sigaddset(&current->blocked, signr);
+		recalc_sigpending();
+		spin_unlock_irq(&current->sighand->siglock);
+	}
+
 	return 1;
 }
 
diff --git a/arch/ppc/kernel/traps.c b/arch/ppc/kernel/traps.c
index cc57bcdda39f..1f1304c15b64 100644
--- a/arch/ppc/kernel/traps.c
+++ b/arch/ppc/kernel/traps.c
@@ -95,14 +95,19 @@ void die(const char * str, struct pt_regs * fp, long err)
 }
 
 void
-_exception(int signr, struct pt_regs *regs)
+_exception(int signr, struct pt_regs *regs, int code, unsigned long addr)
 {
-	if (!user_mode(regs))
-	{
+	siginfo_t info;
+
+	if (!user_mode(regs)) {
 		debugger(regs);
 		die("Exception in kernel mode", regs, signr);
 	}
-	force_sig(signr, current);
+	info.si_signo = signr;
+	info.si_errno = 0;
+	info.si_code = code;
+	info.si_addr = (void *) addr;
+	force_sig_info(signr, &info, current);
 }
 
 /*
@@ -154,12 +159,40 @@ static inline int check_io_access(struct pt_regs *regs)
 	return 0;
 }
 
+#if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
+/* On 4xx, the reason for the machine check or program exception
+   is in the ESR. */
+#define get_reason(regs)	((regs)->dsisr)
+#define REASON_FP		0
+#define REASON_ILLEGAL		ESR_PIL
+#define REASON_PRIVILEGED	ESR_PPR
+#define REASON_TRAP		ESR_PTR
+
+/* single-step stuff */
+#define single_stepping(regs)	(current->thread.dbcr0 & DBCR0_IC)
+#define clear_single_step(regs)	(current->thread.dbcr0 &= ~DBCR0_IC)
+
+#else
+/* On non-4xx, the reason for the machine check or program
+   exception is in the MSR. */
+#define get_reason(regs)	((regs)->msr)
+#define REASON_FP		0x100000
+#define REASON_ILLEGAL		0x80000
+#define REASON_PRIVILEGED	0x40000
+#define REASON_TRAP		0x20000
+
+#define single_stepping(regs)	((regs)->msr & MSR_SE)
+#define clear_single_step(regs)	((regs)->msr &= ~MSR_SE)
+#endif
+
 void
 MachineCheckException(struct pt_regs *regs)
 {
+	unsigned long reason = get_reason(regs);
+
 	if (user_mode(regs)) {
 		regs->msr |= MSR_RI;
-		_exception(SIGSEGV, regs);
+		_exception(SIGBUS, regs, BUS_ADRERR, regs->nip);
 		return;
 	}
 
@@ -178,10 +211,18 @@ MachineCheckException(struct pt_regs *regs)
 	if (check_io_access(regs))
 		return;
 
-#ifndef CONFIG_4xx
-	printk(KERN_CRIT "Machine check in kernel mode.\n");
-	printk(KERN_CRIT "Caused by (from SRR1=%lx): ", regs->msr);
-	switch (regs->msr & 0x601F0000) {
+#ifdef CONFIG_4xx
+	if (reason & ESR_IMCP) {
+		printk("Instruction");
+		mtspr(SPRN_ESR, reason & ~ESR_IMCP);
+	} else
+		printk("Data");
+	printk(" machine check in kernel mode.\n");
+
+#else /* !CONFIG_4xx */
+	printk("Machine check in kernel mode.\n");
+	printk("Caused by (from SRR1=%lx): ", reason);
+	switch (reason & 0x601F0000) {
 	case 0x80000:
 		printk("Machine check signal\n");
 		break;
@@ -208,15 +249,6 @@ MachineCheckException(struct pt_regs *regs)
 	default:
 		printk("Unknown values in msr\n");
 	}
-
-#else /* CONFIG_4xx */
-	/* Note that the ESR gets stored in regs->dsisr on 4xx. */
-	if (regs->dsisr & ESR_MCI) {
-		printk(KERN_CRIT "Instruction");
-		mtspr(SPRN_ESR, regs->dsisr & ~ESR_MCI);
-	} else
-		printk(KERN_CRIT "Data");
-	printk(" machine check in kernel mode.\n");
 #endif /* CONFIG_4xx */
 
 	debugger(regs);
@@ -238,7 +270,7 @@ UnknownException(struct pt_regs *regs)
 {
 	printk("Bad trap at PC: %lx, MSR: %lx, vector=%lx    %s\n",
 	       regs->nip, regs->msr, regs->trap, print_tainted());
-	_exception(SIGTRAP, regs);
+	_exception(SIGTRAP, regs, 0, 0);
 }
 
 void
@@ -246,13 +278,13 @@ InstructionBreakpoint(struct pt_regs *regs)
 {
 	if (debugger_iabr_match(regs))
 		return;
-	_exception(SIGTRAP, regs);
+	_exception(SIGTRAP, regs, TRAP_BRKPT, 0);
 }
 
 void
 RunModeException(struct pt_regs *regs)
 {
-	_exception(SIGTRAP, regs);
+	_exception(SIGTRAP, regs, 0, 0);
 }
 
 /* Illegal instruction emulation support.  Originally written to
@@ -271,17 +303,17 @@ RunModeException(struct pt_regs *regs)
 static int
 emulate_instruction(struct pt_regs *regs)
 {
-	uint    instword;
-	uint    rd;
-	uint    retval;
+	u32 instword;
+	u32 rd;
+	int retval;
 
-	retval = EINVAL;
+	retval = -EINVAL;
 
 	if (!user_mode(regs))
 		return retval;
 	CHECK_FULL_REGS(regs);
 
-	if (get_user(instword, (uint __user *)(regs->nip)))
+	if (get_user(instword, (u32 __user *)(regs->nip)))
 		return -EFAULT;
 
 	/* Emulate the mfspr rD, PVR.
@@ -290,10 +322,23 @@ emulate_instruction(struct pt_regs *regs)
 		rd = (instword >> 21) & 0x1f;
 		regs->gpr[rd] = mfspr(PVR);
 		retval = 0;
-	}
-	if (retval == 0)
 		regs->nip += 4;
-	return(retval);
+	}
+	return retval;
+}
+
+/*
+ * After we have successfully emulated an instruction, we have to
+ * check if the instruction was being single-stepped, and if so,
+ * pretend we got a single-step exception.  This was pointed out
+ * by Kumar Gala.  -- paulus
+ */
+static void emulate_single_step(struct pt_regs *regs)
+{
+	if (single_stepping(regs)) {
+		clear_single_step(regs);
+		_exception(SIGTRAP, regs, TRAP_TRACE, 0);
+	}
 }
 
 /*
@@ -349,29 +394,47 @@ check_bug_trap(struct pt_regs *regs)
 void
 ProgramCheckException(struct pt_regs *regs)
 {
-	int errcode;
-
-#if defined(CONFIG_4xx)
-	unsigned int esr = regs->dsisr;
-	int isbpt = esr & ESR_PTR;
+	unsigned int reason = get_reason(regs);
 	extern int do_mathemu(struct pt_regs *regs);
 
 #ifdef CONFIG_MATH_EMULATION
-	if (!isbpt && do_mathemu(regs) == 0)
+	/* (reason & REASON_ILLEGAL) would be the obvious thing here,
+	 * but there seems to be a hardware bug on the 405GP (RevD)
+	 * that means ESR is sometimes set incorrectly - either to
+	 * ESR_DST (!?) or 0.  In the process of chasing this with the
+	 * hardware people - not sure if it can happen on any illegal
+	 * instruction or only on FP instructions, whether there is a
+	 * pattern to occurences etc. -dgibson 31/Mar/2003 */
+	if (!(reason & REASON_TRAP) && do_mathemu(regs) == 0) {
+		emulate_single_step(regs);
 		return;
+	}
 #endif /* CONFIG_MATH_EMULATION */
 
-#else /* ! CONFIG_4xx */
-	int isbpt = regs->msr & 0x20000;
-
-	if (regs->msr & 0x100000) {
+	if (reason & REASON_FP) {
 		/* IEEE FP exception */
-		_exception(SIGFPE, regs);
+		int code = 0;
+		u32 fpscr;
+
+		if (regs->msr & MSR_FP)
+			giveup_fpu(current);
+		fpscr = current->thread.fpscr;
+		fpscr &= fpscr << 22;	/* mask summary bits with enables */
+		if (fpscr & FPSCR_VX)
+			code = FPE_FLTINV;
+		else if (fpscr & FPSCR_OX)
+			code = FPE_FLTOVF;
+		else if (fpscr & FPSCR_UX)
+			code = FPE_FLTUND;
+		else if (fpscr & FPSCR_ZX)
+			code = FPE_FLTDIV;
+		else if (fpscr & FPSCR_XX)
+			code = FPE_FLTRES;
+		_exception(SIGFPE, regs, code, regs->nip);
 		return;
 	}
-#endif /* ! CONFIG_4xx */
 
-	if (isbpt) {
+	if (reason & REASON_TRAP) {
 		/* trap exception */
 		if (debugger_bpt(regs))
 			return;
@@ -379,17 +442,21 @@ ProgramCheckException(struct pt_regs *regs)
 			regs->nip += 4;
 			return;
 		}
-		_exception(SIGTRAP, regs);
+		_exception(SIGTRAP, regs, TRAP_BRKPT, 0);
 		return;
 	}
 
-	/* Try to emulate it if we should. */
-	if ((errcode = emulate_instruction(regs))) {
-		if (errcode == -EFAULT)
-			_exception(SIGBUS, regs);
-		else
-			_exception(SIGILL, regs);
+	if (reason & REASON_PRIVILEGED) {
+		/* Try to emulate it if we should. */
+		if (emulate_instruction(regs) == 0) {
+			emulate_single_step(regs);
+			return;
+		}
+		_exception(SIGILL, regs, ILL_PRVOPC, regs->nip);
+		return;
 	}
+
+	_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
 }
 
 void
@@ -398,7 +465,7 @@ SingleStepException(struct pt_regs *regs)
 	regs->msr &= ~MSR_SE;  /* Turn off 'trace' bit */
 	if (debugger_sstep(regs))
 		return;
-	_exception(SIGTRAP, regs);
+	_exception(SIGTRAP, regs, TRAP_TRACE, 0);
 }
 
 void
@@ -414,12 +481,12 @@ AlignmentException(struct pt_regs *regs)
 	if (fixed == -EFAULT) {
 		/* fixed == -EFAULT means the operand address was bad */
 		if (user_mode(regs))
-			force_sig(SIGSEGV, current);
+			_exception(SIGSEGV, regs, SEGV_ACCERR, regs->dar);
 		else
 			bad_page_fault(regs, regs->dar, SIGSEGV);
 		return;
 	}
-	_exception(SIGBUS, regs);
+	_exception(SIGBUS, regs, BUS_ADRALN, regs->dar);
 }
 
 void
@@ -470,16 +537,17 @@ SoftwareEmulation(struct pt_regs *regs)
 #endif
 	if (errcode) {
 		if (errcode > 0)
-			_exception(SIGFPE, regs);
+			_exception(SIGFPE, regs, 0, 0);
 		else if (errcode == -EFAULT)
-			_exception(SIGSEGV, regs);
+			_exception(SIGSEGV, regs, 0, 0);
 		else
-			_exception(SIGILL, regs);
-	}
+			_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
+	} else
+		emulate_single_step(regs);
 }
 #endif /* CONFIG_8xx */
 
-#if defined(CONFIG_4xx)
+#if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
 
 void DebugException(struct pt_regs *regs, unsigned long debug_status)
 {
@@ -487,7 +555,7 @@ void DebugException(struct pt_regs *regs, unsigned long debug_status)
 	if (debug_status & DBSR_TIE) {		/* trap instruction*/
 		if (!user_mode(regs) && debugger_bpt(regs))
 			return;
-		_exception(SIGTRAP, regs);
+		_exception(SIGTRAP, regs, 0, 0);
 
 	}
 #endif
@@ -495,10 +563,10 @@ void DebugException(struct pt_regs *regs, unsigned long debug_status)
 		if (!user_mode(regs) && debugger_sstep(regs))
 			return;
 		current->thread.dbcr0 &= ~DBCR0_IC;
-		_exception(SIGTRAP, regs);
+		_exception(SIGTRAP, regs, TRAP_TRACE, 0);
 	}
 }
-#endif /* CONFIG_4xx */
+#endif /* CONFIG_4xx || CONFIG_BOOKE */
 
 #if !defined(CONFIG_TAU_INT)
 void
diff --git a/include/asm-ppc/bitops.h b/include/asm-ppc/bitops.h
index 68e4a5963fb3..e30f536fd830 100644
--- a/include/asm-ppc/bitops.h
+++ b/include/asm-ppc/bitops.h
@@ -276,7 +276,7 @@ static __inline__ int fls(unsigned int x)
  * Find the first bit set in a 140-bit bitmap.
  * The first 100 bits are unlikely to be set.
  */
-static inline int sched_find_first_bit(unsigned long *b)
+static inline int sched_find_first_bit(const unsigned long *b)
 {
 	if (unlikely(b[0]))
 		return __ffs(b[0]);
@@ -295,7 +295,7 @@ static inline int sched_find_first_bit(unsigned long *b)
  * @offset: The bitnumber to start searching at
  * @size: The maximum size to search
  */
-static __inline__ unsigned long find_next_bit(unsigned long *addr,
+static __inline__ unsigned long find_next_bit(const unsigned long *addr,
 	unsigned long size, unsigned long offset)
 {
 	unsigned int *p = ((unsigned int *) addr) + (offset >> 5);
@@ -352,7 +352,7 @@ found_middle:
 #define find_first_zero_bit(addr, size) \
 	find_next_zero_bit((addr), (size), 0)
 
-static __inline__ unsigned long find_next_zero_bit(unsigned long * addr,
+static __inline__ unsigned long find_next_zero_bit(const unsigned long *addr,
 	unsigned long size, unsigned long offset)
 {
 	unsigned int * p = ((unsigned int *) addr) + (offset >> 5);
@@ -411,7 +411,7 @@ static __inline__ int ext2_test_bit(int nr, __const__ void * addr)
 #define ext2_find_first_zero_bit(addr, size) \
         ext2_find_next_zero_bit((addr), (size), 0)
 
-static __inline__ unsigned long ext2_find_next_zero_bit(void *addr,
+static __inline__ unsigned long ext2_find_next_zero_bit(const void *addr,
 	unsigned long size, unsigned long offset)
 {
 	unsigned int *p = ((unsigned int *) addr) + (offset >> 5);
diff --git a/include/asm-ppc/highmem.h b/include/asm-ppc/highmem.h
index ff202f99218a..eb7c3fef6417 100644
--- a/include/asm-ppc/highmem.h
+++ b/include/asm-ppc/highmem.h
@@ -26,6 +26,7 @@
 #include <linux/interrupt.h>
 #include <asm/kmap_types.h>
 #include <asm/tlbflush.h>
+#include <asm/page.h>
 
 /* undef for production */
 #define HIGHMEM_DEBUG 1
@@ -41,8 +42,8 @@ extern void kmap_init(void) __init;
  * easily, subsequent pte tables have to be allocated in one physical
  * chunk of RAM.
  */
-#define PKMAP_BASE CONFIG_HIGHMEM_START
-#define LAST_PKMAP 1024
+#define PKMAP_BASE 	CONFIG_HIGHMEM_START
+#define LAST_PKMAP 	(1 << PTE_SHIFT)
 #define LAST_PKMAP_MASK (LAST_PKMAP-1)
 #define PKMAP_NR(virt)  ((virt-PKMAP_BASE) >> PAGE_SHIFT)
 #define PKMAP_ADDR(nr)  (PKMAP_BASE + ((nr) << PAGE_SHIFT))
diff --git a/include/asm-ppc/processor.h b/include/asm-ppc/processor.h
index e13d0a0b1f45..3a893e9d6b47 100644
--- a/include/asm-ppc/processor.h
+++ b/include/asm-ppc/processor.h
@@ -848,6 +848,7 @@ struct thread_struct {
 	/* AltiVec status */
 	vector128	vscr __attribute((aligned(16)));
 	unsigned long	vrsave;
+	int		used_vr;	/* set if process has used altivec */
 #endif /* CONFIG_ALTIVEC */
 };
 
diff --git a/include/asm-ppc/ucontext.h b/include/asm-ppc/ucontext.h
index 14f1e78c041d..1d6e70c4306d 100644
--- a/include/asm-ppc/ucontext.h
+++ b/include/asm-ppc/ucontext.h
@@ -1,14 +1,28 @@
 #ifndef _ASMPPC_UCONTEXT_H
 #define _ASMPPC_UCONTEXT_H
 
-/* Copied from i386. */
+#include <asm/elf.h>
+#include <asm/signal.h>
+
+struct mcontext {
+	elf_gregset_t	mc_gregs;
+	elf_fpregset_t	mc_fregs;
+	unsigned long	mc_pad[2];
+	elf_vrregset_t	mc_vregs __attribute__((__aligned__(16)));
+};
 
 struct ucontext {
-	unsigned long	  uc_flags;
-	struct ucontext  *uc_link;
-	stack_t		  uc_stack;
-	struct sigcontext uc_mcontext;
-	sigset_t	  uc_sigmask;	/* mask last for extensibility */
+	unsigned long	 uc_flags;
+	struct ucontext *uc_link;
+	stack_t		 uc_stack;
+	int		 uc_pad[7];
+	struct mcontext	*uc_regs;	/* backward compat */
+	sigset_t	 uc_oldsigmask;	/* backward compat */
+	int		 uc_pad2;
+	sigset_t	 uc_sigmask;
+	/* glibc has 1024-bit signal masks, ours are 64-bit */
+	int		 uc_maskext[30];
+	struct mcontext	 uc_mcontext;
 };
 
 #endif /* !_ASMPPC_UCONTEXT_H */