Merge branch 'work.regset' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull ptrace regset updates from Al Viro:
 "Internal regset API changes:

   - regularize copy_regset_{to,from}_user() callers

   - switch to saner calling conventions for ->get()

   - kill user_regset_copyout()

  The ->put() side of things will have to wait for the next cycle,
  unfortunately.

  The balance is about -1KLoC and replacements for ->get() instances are
  a lot saner"

* 'work.regset' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (41 commits)
  regset: kill user_regset_copyout{,_zero}()
  regset(): kill ->get_size()
  regset: kill ->get()
  csky: switch to ->regset_get()
  xtensa: switch to ->regset_get()
  parisc: switch to ->regset_get()
  nds32: switch to ->regset_get()
  nios2: switch to ->regset_get()
  hexagon: switch to ->regset_get()
  h8300: switch to ->regset_get()
  openrisc: switch to ->regset_get()
  riscv: switch to ->regset_get()
  c6x: switch to ->regset_get()
  ia64: switch to ->regset_get()
  arc: switch to ->regset_get()
  arm: switch to ->regset_get()
  sh: convert to ->regset_get()
  arm64: switch to ->regset_get()
  mips: switch to ->regset_get()
  sparc: switch to ->regset_get()
  ...

2 files changed, 433 insertions, 427 deletions

diff --git a/arch/sparc/kernel/ptrace_32.c b/arch/sparc/kernel/ptrace_32.c
index 47eb315d411c..5318174a0268 100644
--- a/arch/sparc/kernel/ptrace_32.c
+++ b/arch/sparc/kernel/ptrace_32.c
@@ -83,41 +83,25 @@ static int regwindow32_set(struct task_struct *target,
 
 static int genregs32_get(struct task_struct *target,
 			 const struct user_regset *regset,
-			 unsigned int pos, unsigned int count,
-			 void *kbuf, void __user *ubuf)
+			 struct membuf to)
 {
 	const struct pt_regs *regs = target->thread.kregs;
 	u32 uregs[16];
-	int ret;
 
 	if (target == current)
 		flush_user_windows();
 
-	ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
-				  regs->u_regs,
-				  0, 16 * sizeof(u32));
-	if (ret || !count)
-		return ret;
-
-	if (pos < 32 * sizeof(u32)) {
-		if (regwindow32_get(target, regs, uregs))
-			return -EFAULT;
-		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
-					  uregs,
-					  16 * sizeof(u32), 32 * sizeof(u32));
-		if (ret || !count)
-			return ret;
-	}
-
-	uregs[0] = regs->psr;
-	uregs[1] = regs->pc;
-	uregs[2] = regs->npc;
-	uregs[3] = regs->y;
-	uregs[4] = 0;	/* WIM */
-	uregs[5] = 0;	/* TBR */
-	return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
-				  uregs,
-				  32 * sizeof(u32), 38 * sizeof(u32));
+	membuf_write(&to, regs->u_regs, 16 * sizeof(u32));
+	if (!to.left)
+		return 0;
+	if (regwindow32_get(target, regs, uregs))
+		return -EFAULT;
+	membuf_write(&to, uregs, 16 * sizeof(u32));
+	membuf_store(&to, regs->psr);
+	membuf_store(&to, regs->pc);
+	membuf_store(&to, regs->npc);
+	membuf_store(&to, regs->y);
+	return membuf_zero(&to, 2 * sizeof(u32));
 }
 
 static int genregs32_set(struct task_struct *target,
@@ -139,19 +123,18 @@ static int genregs32_set(struct task_struct *target,
 	if (ret || !count)
 		return ret;
 
-	if (pos < 32 * sizeof(u32)) {
-		if (regwindow32_get(target, regs, uregs))
-			return -EFAULT;
-		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
-					 uregs,
-					 16 * sizeof(u32), 32 * sizeof(u32));
-		if (ret)
-			return ret;
-		if (regwindow32_set(target, regs, uregs))
-			return -EFAULT;
-		if (!count)
-			return 0;
-	}
+	if (regwindow32_get(target, regs, uregs))
+		return -EFAULT;
+	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+				 uregs,
+				 16 * sizeof(u32), 32 * sizeof(u32));
+	if (ret)
+		return ret;
+	if (regwindow32_set(target, regs, uregs))
+		return -EFAULT;
+	if (!count)
+		return 0;
+
 	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 				 &psr,
 				 32 * sizeof(u32), 33 * sizeof(u32));
@@ -182,46 +165,18 @@ static int genregs32_set(struct task_struct *target,
 
 static int fpregs32_get(struct task_struct *target,
 			const struct user_regset *regset,
-			unsigned int pos, unsigned int count,
-			void *kbuf, void __user *ubuf)
+			struct membuf to)
 {
-	const unsigned long *fpregs = target->thread.float_regs;
-	int ret = 0;
-
 #if 0
 	if (target == current)
 		save_and_clear_fpu();
 #endif
 
-	ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
-				  fpregs,
-				  0, 32 * sizeof(u32));
-
-	if (!ret)
-		ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
-					       32 * sizeof(u32),
-					       33 * sizeof(u32));
-	if (!ret)
-		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
-					  &target->thread.fsr,
-					  33 * sizeof(u32),
-					  34 * sizeof(u32));
-
-	if (!ret) {
-		unsigned long val;
-
-		val = (1 << 8) | (8 << 16);
-		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
-					  &val,
-					  34 * sizeof(u32),
-					  35 * sizeof(u32));
-	}
-
-	if (!ret)
-		ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
-					       35 * sizeof(u32), -1);
-
-	return ret;
+	membuf_write(&to, target->thread.float_regs, 32 * sizeof(u32));
+	membuf_zero(&to, sizeof(u32));
+	membuf_write(&to, &target->thread.fsr, sizeof(u32));
+	membuf_store(&to, (u32)((1 << 8) | (8 << 16)));
+	return membuf_zero(&to, 64 * sizeof(u32));
 }
 
 static int fpregs32_set(struct task_struct *target,
@@ -243,13 +198,11 @@ static int fpregs32_set(struct task_struct *target,
 		user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 					  32 * sizeof(u32),
 					  33 * sizeof(u32));
-	if (!ret && count > 0) {
+	if (!ret)
 		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 					 &target->thread.fsr,
 					 33 * sizeof(u32),
 					 34 * sizeof(u32));
-	}
-
 	if (!ret)
 		ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 						34 * sizeof(u32), -1);
@@ -268,7 +221,7 @@ static const struct user_regset sparc32_regsets[] = {
 		.core_note_type = NT_PRSTATUS,
 		.n = 38,
 		.size = sizeof(u32), .align = sizeof(u32),
-		.get = genregs32_get, .set = genregs32_set
+		.regset_get = genregs32_get, .set = genregs32_set
 	},
 	/* Format is:
 	 *	F0 --> F31
@@ -284,10 +237,104 @@ static const struct user_regset sparc32_regsets[] = {
 		.core_note_type = NT_PRFPREG,
 		.n = 99,
 		.size = sizeof(u32), .align = sizeof(u32),
-		.get = fpregs32_get, .set = fpregs32_set
+		.regset_get = fpregs32_get, .set = fpregs32_set
+	},
+};
+
+static int getregs_get(struct task_struct *target,
+			 const struct user_regset *regset,
+			 struct membuf to)
+{
+	const struct pt_regs *regs = target->thread.kregs;
+
+	if (target == current)
+		flush_user_windows();
+
+	membuf_store(&to, regs->psr);
+	membuf_store(&to, regs->pc);
+	membuf_store(&to, regs->npc);
+	membuf_store(&to, regs->y);
+	return membuf_write(&to, regs->u_regs + 1, 15 * sizeof(u32));
+}
+
+static int setregs_set(struct task_struct *target,
+			 const struct user_regset *regset,
+			 unsigned int pos, unsigned int count,
+			 const void *kbuf, const void __user *ubuf)
+{
+	struct pt_regs *regs = target->thread.kregs;
+	u32 v[4];
+	int ret;
+
+	if (target == current)
+		flush_user_windows();
+
+	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+				 v,
+				 0, 4 * sizeof(u32));
+	if (ret)
+		return ret;
+	regs->psr = (regs->psr & ~(PSR_ICC | PSR_SYSCALL)) |
+		    (v[0] & (PSR_ICC | PSR_SYSCALL));
+	regs->pc = v[1];
+	regs->npc = v[2];
+	regs->y = v[3];
+	return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+				 regs->u_regs + 1,
+				 4 * sizeof(u32) , 19 * sizeof(u32));
+}
+
+static int getfpregs_get(struct task_struct *target,
+			const struct user_regset *regset,
+			struct membuf to)
+{
+#if 0
+	if (target == current)
+		save_and_clear_fpu();
+#endif
+	membuf_write(&to, &target->thread.float_regs, 32 * sizeof(u32));
+	membuf_write(&to, &target->thread.fsr, sizeof(u32));
+	return membuf_zero(&to, 35 * sizeof(u32));
+}
+
+static int setfpregs_set(struct task_struct *target,
+			const struct user_regset *regset,
+			unsigned int pos, unsigned int count,
+			const void *kbuf, const void __user *ubuf)
+{
+	unsigned long *fpregs = target->thread.float_regs;
+	int ret;
+
+#if 0
+	if (target == current)
+		save_and_clear_fpu();
+#endif
+	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+				 fpregs,
+				 0, 32 * sizeof(u32));
+	if (ret)
+		return ret;
+	return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+				 &target->thread.fsr,
+				 32 * sizeof(u32),
+				 33 * sizeof(u32));
+}
+
+static const struct user_regset ptrace32_regsets[] = {
+	[REGSET_GENERAL] = {
+		.n = 19, .size = sizeof(u32),
+		.regset_get = getregs_get, .set = setregs_set,
+	},
+	[REGSET_FP] = {
+		.n = 68, .size = sizeof(u32),
+		.regset_get = getfpregs_get, .set = setfpregs_set,
 	},
 };
 
+static const struct user_regset_view ptrace32_view = {
+	.regsets = ptrace32_regsets, .n = ARRAY_SIZE(ptrace32_regsets)
+};
+
 static const struct user_regset_view user_sparc32_view = {
 	.name = "sparc", .e_machine = EM_SPARC,
 	.regsets = sparc32_regsets, .n = ARRAY_SIZE(sparc32_regsets)
@@ -315,74 +362,44 @@ long arch_ptrace(struct task_struct *child, long request,
 {
 	unsigned long addr2 = current->thread.kregs->u_regs[UREG_I4];
 	void __user *addr2p;
-	const struct user_regset_view *view;
 	struct pt_regs __user *pregs;
 	struct fps __user *fps;
 	int ret;
 
-	view = task_user_regset_view(current);
 	addr2p = (void __user *) addr2;
 	pregs = (struct pt_regs __user *) addr;
 	fps = (struct fps __user *) addr;
 
 	switch(request) {
 	case PTRACE_GETREGS: {
-		ret = copy_regset_to_user(child, view, REGSET_GENERAL,
-					  32 * sizeof(u32),
-					  4 * sizeof(u32),
-					  &pregs->psr);
-		if (!ret)
-			copy_regset_to_user(child, view, REGSET_GENERAL,
-					    1 * sizeof(u32),
-					    15 * sizeof(u32),
-					    &pregs->u_regs[0]);
+		ret = copy_regset_to_user(child, &ptrace32_view,
+					  REGSET_GENERAL, 0,
+					  19 * sizeof(u32),
+					  pregs);
 		break;
 	}
 
 	case PTRACE_SETREGS: {
-		ret = copy_regset_from_user(child, view, REGSET_GENERAL,
-					    32 * sizeof(u32),
-					    4 * sizeof(u32),
-					    &pregs->psr);
-		if (!ret)
-			copy_regset_from_user(child, view, REGSET_GENERAL,
-					      1 * sizeof(u32),
-					      15 * sizeof(u32),
-					      &pregs->u_regs[0]);
+		ret = copy_regset_from_user(child, &ptrace32_view,
+					    REGSET_GENERAL, 0,
+					    19 * sizeof(u32),
+					    pregs);
 		break;
 	}
 
 	case PTRACE_GETFPREGS: {
-		ret = copy_regset_to_user(child, view, REGSET_FP,
-					  0 * sizeof(u32),
-					  32 * sizeof(u32),
-					  &fps->regs[0]);
-		if (!ret)
-			ret = copy_regset_to_user(child, view, REGSET_FP,
-						  33 * sizeof(u32),
-						  1 * sizeof(u32),
-						  &fps->fsr);
-
-		if (!ret) {
-			if (__put_user(0, &fps->fpqd) ||
-			    __put_user(0, &fps->flags) ||
-			    __put_user(0, &fps->extra) ||
-			    clear_user(fps->fpq, sizeof(fps->fpq)))
-				ret = -EFAULT;
-		}
+		ret = copy_regset_to_user(child, &ptrace32_view,
+					  REGSET_FP, 0,
+					  68 * sizeof(u32),
+					  fps);
 		break;
 	}
 
 	case PTRACE_SETFPREGS: {
-		ret = copy_regset_from_user(child, view, REGSET_FP,
-					    0 * sizeof(u32),
-					    32 * sizeof(u32),
-					    &fps->regs[0]);
-		if (!ret)
-			ret = copy_regset_from_user(child, view, REGSET_FP,
-						    33 * sizeof(u32),
-						    1 * sizeof(u32),
-						    &fps->fsr);
+		ret = copy_regset_from_user(child, &ptrace32_view,
+					  REGSET_FP, 0,
+					  33 * sizeof(u32),
+					  fps);
 		break;
 	}
 
diff --git a/arch/sparc/kernel/ptrace_64.c b/arch/sparc/kernel/ptrace_64.c
index 7122efb4b1cc..2b92155db8a5 100644
--- a/arch/sparc/kernel/ptrace_64.c
+++ b/arch/sparc/kernel/ptrace_64.c
@@ -246,52 +246,23 @@ enum sparc_regset {
 
 static int genregs64_get(struct task_struct *target,
 			 const struct user_regset *regset,
-			 unsigned int pos, unsigned int count,
-			 void *kbuf, void __user *ubuf)
+			 struct membuf to)
 {
 	const struct pt_regs *regs = task_pt_regs(target);
-	int ret;
+	struct reg_window window;
 
 	if (target == current)
 		flushw_user();
 
-	ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
-				  regs->u_regs,
-				  0, 16 * sizeof(u64));
-	if (!ret && count && pos < (32 * sizeof(u64))) {
-		struct reg_window window;
-
-		if (regwindow64_get(target, regs, &window))
-			return -EFAULT;
-		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
-					  &window,
-					  16 * sizeof(u64),
-					  32 * sizeof(u64));
-	}
-
-	if (!ret) {
-		/* TSTATE, TPC, TNPC */
-		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
-					  &regs->tstate,
-					  32 * sizeof(u64),
-					  35 * sizeof(u64));
-	}
-
-	if (!ret) {
-		unsigned long y = regs->y;
-
-		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
-					  &y,
-					  35 * sizeof(u64),
-					  36 * sizeof(u64));
-	}
-
-	if (!ret) {
-		ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
-					       36 * sizeof(u64), -1);
-
-	}
-	return ret;
+	membuf_write(&to, regs->u_regs, 16 * sizeof(u64));
+	if (!to.left)
+		return 0;
+	if (regwindow64_get(target, regs, &window))
+		return -EFAULT;
+	membuf_write(&to, &window, 16 * sizeof(u64));
+	/* TSTATE, TPC, TNPC */
+	membuf_write(&to, &regs->tstate, 3 * sizeof(u64));
+	return membuf_store(&to, (u64)regs->y);
 }
 
 static int genregs64_set(struct task_struct *target,
@@ -370,69 +341,32 @@ static int genregs64_set(struct task_struct *target,
 
 static int fpregs64_get(struct task_struct *target,
 			const struct user_regset *regset,
-			unsigned int pos, unsigned int count,
-			void *kbuf, void __user *ubuf)
+			struct membuf to)
 {
-	const unsigned long *fpregs = task_thread_info(target)->fpregs;
-	unsigned long fprs, fsr, gsr;
-	int ret;
+	struct thread_info *t = task_thread_info(target);
+	unsigned long fprs;
 
 	if (target == current)
 		save_and_clear_fpu();
 
-	fprs = task_thread_info(target)->fpsaved[0];
+	fprs = t->fpsaved[0];
 
 	if (fprs & FPRS_DL)
-		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
-					  fpregs,
-					  0, 16 * sizeof(u64));
+		membuf_write(&to, t->fpregs, 16 * sizeof(u64));
 	else
-		ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
-					       0,
-					       16 * sizeof(u64));
-
-	if (!ret) {
-		if (fprs & FPRS_DU)
-			ret = user_regset_copyout(&pos, &count,
-						  &kbuf, &ubuf,
-						  fpregs + 16,
-						  16 * sizeof(u64),
-						  32 * sizeof(u64));
-		else
-			ret = user_regset_copyout_zero(&pos, &count,
-						       &kbuf, &ubuf,
-						       16 * sizeof(u64),
-						       32 * sizeof(u64));
-	}
+		membuf_zero(&to, 16 * sizeof(u64));
 
+	if (fprs & FPRS_DU)
+		membuf_write(&to, t->fpregs + 16, 16 * sizeof(u64));
+	else
+		membuf_zero(&to, 16 * sizeof(u64));
 	if (fprs & FPRS_FEF) {
-		fsr = task_thread_info(target)->xfsr[0];
-		gsr = task_thread_info(target)->gsr[0];
+		membuf_store(&to, t->xfsr[0]);
+		membuf_store(&to, t->gsr[0]);
 	} else {
-		fsr = gsr = 0;
+		membuf_zero(&to, 2 * sizeof(u64));
 	}
-
-	if (!ret)
-		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
-					  &fsr,
-					  32 * sizeof(u64),
-					  33 * sizeof(u64));
-	if (!ret)
-		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
-					  &gsr,
-					  33 * sizeof(u64),
-					  34 * sizeof(u64));
-	if (!ret)
-		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
-					  &fprs,
-					  34 * sizeof(u64),
-					  35 * sizeof(u64));
-
-	if (!ret)
-		ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
-					       35 * sizeof(u64), -1);
-
-	return ret;
+	return membuf_store(&to, fprs);
 }
 
 static int fpregs64_set(struct task_struct *target,
@@ -490,7 +424,7 @@ static const struct user_regset sparc64_regsets[] = {
 		.core_note_type = NT_PRSTATUS,
 		.n = 36,
 		.size = sizeof(u64), .align = sizeof(u64),
-		.get = genregs64_get, .set = genregs64_set
+		.regset_get = genregs64_get, .set = genregs64_set
 	},
 	/* Format is:
 	 *	F0 --> F63
@@ -502,10 +436,96 @@ static const struct user_regset sparc64_regsets[] = {
 		.core_note_type = NT_PRFPREG,
 		.n = 35,
 		.size = sizeof(u64), .align = sizeof(u64),
-		.get = fpregs64_get, .set = fpregs64_set
+		.regset_get = fpregs64_get, .set = fpregs64_set
+	},
+};
+
+static int getregs64_get(struct task_struct *target,
+			 const struct user_regset *regset,
+			 struct membuf to)
+{
+	const struct pt_regs *regs = task_pt_regs(target);
+
+	if (target == current)
+		flushw_user();
+
+	membuf_write(&to, regs->u_regs + 1, 15 * sizeof(u64));
+	membuf_store(&to, (u64)0);
+	membuf_write(&to, &regs->tstate, 3 * sizeof(u64));
+	return membuf_store(&to, (u64)regs->y);
+}
+
+static int setregs64_set(struct task_struct *target,
+			 const struct user_regset *regset,
+			 unsigned int pos, unsigned int count,
+			 const void *kbuf, const void __user *ubuf)
+{
+	struct pt_regs *regs = task_pt_regs(target);
+	unsigned long y = regs->y;
+	unsigned long tstate;
+	int ret;
+
+	if (target == current)
+		flushw_user();
+
+	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+				 regs->u_regs + 1,
+				 0 * sizeof(u64),
+				 15 * sizeof(u64));
+	if (ret)
+		return ret;
+	ret =user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
+				 15 * sizeof(u64), 16 * sizeof(u64));
+	if (ret)
+		return ret;
+	/* TSTATE */
+	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+				 &tstate,
+				 16 * sizeof(u64),
+				 17 * sizeof(u64));
+	if (ret)
+		return ret;
+	/* Only the condition codes and the "in syscall"
+	 * state can be modified in the %tstate register.
+	 */
+	tstate &= (TSTATE_ICC | TSTATE_XCC | TSTATE_SYSCALL);
+	regs->tstate &= ~(TSTATE_ICC | TSTATE_XCC | TSTATE_SYSCALL);
+	regs->tstate |= tstate;
+
+	/* TPC, TNPC */
+	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+				 &regs->tpc,
+				 17 * sizeof(u64),
+				 19 * sizeof(u64));
+	if (ret)
+		return ret;
+	/* Y */
+	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+				 &y,
+				 19 * sizeof(u64),
+				 20 * sizeof(u64));
+	if (!ret)
+		regs->y = y;
+	return ret;
+}
+
+static const struct user_regset ptrace64_regsets[] = {
+	/* Format is:
+	 *      G1 --> G7
+	 *      O0 --> O7
+	 *	0
+	 *      TSTATE, TPC, TNPC, Y
+	 */
+	[REGSET_GENERAL] = {
+		.n = 20, .size = sizeof(u64),
+		.regset_get = getregs64_get, .set = setregs64_set,
 	},
 };
 
+static const struct user_regset_view ptrace64_view = {
+	.regsets = ptrace64_regsets, .n = ARRAY_SIZE(ptrace64_regsets)
+};
+
 static const struct user_regset_view user_sparc64_view = {
 	.name = "sparc64", .e_machine = EM_SPARCV9,
 	.regsets = sparc64_regsets, .n = ARRAY_SIZE(sparc64_regsets)
@@ -514,108 +534,28 @@ static const struct user_regset_view user_sparc64_view = {
 #ifdef CONFIG_COMPAT
 static int genregs32_get(struct task_struct *target,
 			 const struct user_regset *regset,
-			 unsigned int pos, unsigned int count,
-			 void *kbuf, void __user *ubuf)
+			 struct membuf to)
 {
 	const struct pt_regs *regs = task_pt_regs(target);
-	compat_ulong_t __user *reg_window;
-	compat_ulong_t *k = kbuf;
-	compat_ulong_t __user *u = ubuf;
-	compat_ulong_t reg;
+	u32 uregs[16];
+	int i;
 
 	if (target == current)
 		flushw_user();
 
-	pos /= sizeof(reg);
-	count /= sizeof(reg);
-
-	if (kbuf) {
-		for (; count > 0 && pos < 16; count--)
-			*k++ = regs->u_regs[pos++];
-
-		reg_window = (compat_ulong_t __user *) regs->u_regs[UREG_I6];
-		reg_window -= 16;
-		if (target == current) {
-			for (; count > 0 && pos < 32; count--) {
-				if (get_user(*k++, &reg_window[pos++]))
-					return -EFAULT;
-			}
-		} else {
-			for (; count > 0 && pos < 32; count--) {
-				if (access_process_vm(target,
-						      (unsigned long)
-						      &reg_window[pos],
-						      k, sizeof(*k),
-						      FOLL_FORCE)
-				    != sizeof(*k))
-					return -EFAULT;
-				k++;
-				pos++;
-			}
-		}
-	} else {
-		for (; count > 0 && pos < 16; count--) {
-			if (put_user((compat_ulong_t) regs->u_regs[pos++], u++))
-				return -EFAULT;
-		}
-
-		reg_window = (compat_ulong_t __user *) regs->u_regs[UREG_I6];
-		reg_window -= 16;
-		if (target == current) {
-			for (; count > 0 && pos < 32; count--) {
-				if (get_user(reg, &reg_window[pos++]) ||
-				    put_user(reg, u++))
-					return -EFAULT;
-			}
-		} else {
-			for (; count > 0 && pos < 32; count--) {
-				if (access_process_vm(target,
-						      (unsigned long)
-						      &reg_window[pos++],
-						      &reg, sizeof(reg),
-						      FOLL_FORCE)
-				    != sizeof(reg))
-					return -EFAULT;
-				if (put_user(reg, u++))
-					return -EFAULT;
-			}
-		}
-	}
-	while (count > 0) {
-		switch (pos) {
-		case 32: /* PSR */
-			reg = tstate_to_psr(regs->tstate);
-			break;
-		case 33: /* PC */
-			reg = regs->tpc;
-			break;
-		case 34: /* NPC */
-			reg = regs->tnpc;
-			break;
-		case 35: /* Y */
-			reg = regs->y;
-			break;
-		case 36: /* WIM */
-		case 37: /* TBR */
-			reg = 0;
-			break;
-		default:
-			goto finish;
-		}
-
-		if (kbuf)
-			*k++ = reg;
-		else if (put_user(reg, u++))
-			return -EFAULT;
-		pos++;
-		count--;
-	}
-finish:
-	pos *= sizeof(reg);
-	count *= sizeof(reg);
-
-	return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
-					38 * sizeof(reg), -1);
+	for (i = 0; i < 16; i++)
+		membuf_store(&to, (u32)regs->u_regs[i]);
+	if (!to.left)
+		return 0;
+	if (get_from_target(target, regs->u_regs[UREG_I6],
+			    uregs, sizeof(uregs)))
+		return -EFAULT;
+	membuf_write(&to, uregs, 16 * sizeof(u32));
+	membuf_store(&to, (u32)tstate_to_psr(regs->tstate));
+	membuf_store(&to, (u32)(regs->tpc));
+	membuf_store(&to, (u32)(regs->tnpc));
+	membuf_store(&to, (u32)(regs->y));
+	return membuf_zero(&to, 2 * sizeof(u32));
 }
 
 static int genregs32_set(struct task_struct *target,
@@ -737,56 +677,24 @@ finish:
 
 static int fpregs32_get(struct task_struct *target,
 			const struct user_regset *regset,
-			unsigned int pos, unsigned int count,
-			void *kbuf, void __user *ubuf)
+			struct membuf to)
 {
-	const unsigned long *fpregs = task_thread_info(target)->fpregs;
-	compat_ulong_t enabled;
-	unsigned long fprs;
-	compat_ulong_t fsr;
-	int ret = 0;
+	struct thread_info *t = task_thread_info(target);
+	bool enabled;
 
 	if (target == current)
 		save_and_clear_fpu();
 
-	fprs = task_thread_info(target)->fpsaved[0];
-	if (fprs & FPRS_FEF) {
-		fsr = task_thread_info(target)->xfsr[0];
-		enabled = 1;
-	} else {
-		fsr = 0;
-		enabled = 0;
-	}
-
-	ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
-				  fpregs,
-				  0, 32 * sizeof(u32));
-
-	if (!ret)
-		ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
-					       32 * sizeof(u32),
-					       33 * sizeof(u32));
-	if (!ret)
-		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
-					  &fsr,
-					  33 * sizeof(u32),
-					  34 * sizeof(u32));
-
-	if (!ret) {
-		compat_ulong_t val;
-
-		val = (enabled << 8) | (8 << 16);
-		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
-					  &val,
-					  34 * sizeof(u32),
-					  35 * sizeof(u32));
-	}
+	enabled = t->fpsaved[0] & FPRS_FEF;
 
-	if (!ret)
-		ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
-					       35 * sizeof(u32), -1);
-
-	return ret;
+	membuf_write(&to, t->fpregs, 32 * sizeof(u32));
+	membuf_zero(&to, sizeof(u32));
+	if (enabled)
+		membuf_store(&to, (u32)t->xfsr[0]);
+	else
+		membuf_zero(&to, sizeof(u32));
+	membuf_store(&to, (u32)((enabled << 8) | (8 << 16)));
+	return membuf_zero(&to, 64 * sizeof(u32));
 }
 
 static int fpregs32_set(struct task_struct *target,
@@ -847,7 +755,7 @@ static const struct user_regset sparc32_regsets[] = {
 		.core_note_type = NT_PRSTATUS,
 		.n = 38,
 		.size = sizeof(u32), .align = sizeof(u32),
-		.get = genregs32_get, .set = genregs32_set
+		.regset_get = genregs32_get, .set = genregs32_set
 	},
 	/* Format is:
 	 *	F0 --> F31
@@ -863,10 +771,133 @@ static const struct user_regset sparc32_regsets[] = {
 		.core_note_type = NT_PRFPREG,
 		.n = 99,
 		.size = sizeof(u32), .align = sizeof(u32),
-		.get = fpregs32_get, .set = fpregs32_set
+		.regset_get = fpregs32_get, .set = fpregs32_set
 	},
 };
 
+static int getregs_get(struct task_struct *target,
+			 const struct user_regset *regset,
+			 struct membuf to)
+{
+	const struct pt_regs *regs = task_pt_regs(target);
+	int i;
+
+	if (target == current)
+		flushw_user();
+
+	membuf_store(&to, (u32)tstate_to_psr(regs->tstate));
+	membuf_store(&to, (u32)(regs->tpc));
+	membuf_store(&to, (u32)(regs->tnpc));
+	membuf_store(&to, (u32)(regs->y));
+	for (i = 1; i < 16; i++)
+		membuf_store(&to, (u32)regs->u_regs[i]);
+	return to.left;
+}
+
+static int setregs_set(struct task_struct *target,
+			 const struct user_regset *regset,
+			 unsigned int pos, unsigned int count,
+			 const void *kbuf, const void __user *ubuf)
+{
+	struct pt_regs *regs = task_pt_regs(target);
+	unsigned long tstate;
+	u32 uregs[19];
+	int i, ret;
+
+	if (target == current)
+		flushw_user();
+
+	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+				 uregs,
+				 0, 19 * sizeof(u32));
+	if (ret)
+		return ret;
+
+	tstate = regs->tstate;
+	tstate &= ~(TSTATE_ICC | TSTATE_XCC | TSTATE_SYSCALL);
+	tstate |= psr_to_tstate_icc(uregs[0]);
+	if (uregs[0] & PSR_SYSCALL)
+		tstate |= TSTATE_SYSCALL;
+	regs->tstate = tstate;
+	regs->tpc = uregs[1];
+	regs->tnpc = uregs[2];
+	regs->y = uregs[3];
+
+	for (i = 1; i < 15; i++)
+		regs->u_regs[i] = uregs[3 + i];
+	return 0;
+}
+
+static int getfpregs_get(struct task_struct *target,
+			const struct user_regset *regset,
+			struct membuf to)
+{
+	struct thread_info *t = task_thread_info(target);
+
+	if (target == current)
+		save_and_clear_fpu();
+
+	membuf_write(&to, t->fpregs, 32 * sizeof(u32));
+	if (t->fpsaved[0] & FPRS_FEF)
+		membuf_store(&to, (u32)t->xfsr[0]);
+	else
+		membuf_zero(&to, sizeof(u32));
+	return membuf_zero(&to, 35 * sizeof(u32));
+}
+
+static int setfpregs_set(struct task_struct *target,
+			const struct user_regset *regset,
+			unsigned int pos, unsigned int count,
+			const void *kbuf, const void __user *ubuf)
+{
+	unsigned long *fpregs = task_thread_info(target)->fpregs;
+	unsigned long fprs;
+	int ret;
+
+	if (target == current)
+		save_and_clear_fpu();
+
+	fprs = task_thread_info(target)->fpsaved[0];
+
+	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+				 fpregs,
+				 0, 32 * sizeof(u32));
+	if (!ret) {
+		compat_ulong_t fsr;
+		unsigned long val;
+
+		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+					 &fsr,
+					 32 * sizeof(u32),
+					 33 * sizeof(u32));
+		if (!ret) {
+			val = task_thread_info(target)->xfsr[0];
+			val &= 0xffffffff00000000UL;
+			val |= fsr;
+			task_thread_info(target)->xfsr[0] = val;
+		}
+	}
+
+	fprs |= (FPRS_FEF | FPRS_DL);
+	task_thread_info(target)->fpsaved[0] = fprs;
+	return ret;
+}
+
+static const struct user_regset ptrace32_regsets[] = {
+	[REGSET_GENERAL] = {
+		.n = 19, .size = sizeof(u32),
+		.regset_get = getregs_get, .set = setregs_set,
+	},
+	[REGSET_FP] = {
+		.n = 68, .size = sizeof(u32),
+		.regset_get = getfpregs_get, .set = setfpregs_set,
+	},
+};
+
+static const struct user_regset_view ptrace32_view = {
+	.regsets = ptrace32_regsets, .n = ARRAY_SIZE(ptrace32_regsets)
+};
+
 static const struct user_regset_view user_sparc32_view = {
 	.name = "sparc", .e_machine = EM_SPARC,
 	.regsets = sparc32_regsets, .n = ARRAY_SIZE(sparc32_regsets)
@@ -898,7 +929,6 @@ struct compat_fps {
 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 			compat_ulong_t caddr, compat_ulong_t cdata)
 {
-	const struct user_regset_view *view = task_user_regset_view(current);
 	compat_ulong_t caddr2 = task_pt_regs(current)->u_regs[UREG_I4];
 	struct pt_regs32 __user *pregs;
 	struct compat_fps __user *fps;
@@ -916,58 +946,31 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 		break;
 
 	case PTRACE_GETREGS:
-		ret = copy_regset_to_user(child, view, REGSET_GENERAL,
-					  32 * sizeof(u32),
-					  4 * sizeof(u32),
-					  &pregs->psr);
-		if (!ret)
-			ret = copy_regset_to_user(child, view, REGSET_GENERAL,
-						  1 * sizeof(u32),
-						  15 * sizeof(u32),
-						  &pregs->u_regs[0]);
+		ret = copy_regset_to_user(child, &ptrace32_view,
+					  REGSET_GENERAL, 0,
+					  19 * sizeof(u32),
+					  pregs);
 		break;
 
 	case PTRACE_SETREGS:
-		ret = copy_regset_from_user(child, view, REGSET_GENERAL,
-					    32 * sizeof(u32),
-					    4 * sizeof(u32),
-					    &pregs->psr);
-		if (!ret)
-			ret = copy_regset_from_user(child, view, REGSET_GENERAL,
-						    1 * sizeof(u32),
-						    15 * sizeof(u32),
-						    &pregs->u_regs[0]);
+		ret = copy_regset_from_user(child, &ptrace32_view,
+					  REGSET_GENERAL, 0,
+					  19 * sizeof(u32),
+					  pregs);
 		break;
 
 	case PTRACE_GETFPREGS:
-		ret = copy_regset_to_user(child, view, REGSET_FP,
-					  0 * sizeof(u32),
-					  32 * sizeof(u32),
-					  &fps->regs[0]);
-		if (!ret)
-			ret = copy_regset_to_user(child, view, REGSET_FP,
-						  33 * sizeof(u32),
-						  1 * sizeof(u32),
-						  &fps->fsr);
-		if (!ret) {
-			if (__put_user(0, &fps->flags) ||
-			    __put_user(0, &fps->extra) ||
-			    __put_user(0, &fps->fpqd) ||
-			    clear_user(&fps->fpq[0], 32 * sizeof(unsigned int)))
-				ret = -EFAULT;
-		}
+		ret = copy_regset_to_user(child, &ptrace32_view,
+					  REGSET_FP, 0,
+					  68 * sizeof(u32),
+					  fps);
 		break;
 
 	case PTRACE_SETFPREGS:
-		ret = copy_regset_from_user(child, view, REGSET_FP,
-					    0 * sizeof(u32),
-					    32 * sizeof(u32),
-					    &fps->regs[0]);
-		if (!ret)
-			ret = copy_regset_from_user(child, view, REGSET_FP,
-						    33 * sizeof(u32),
-						    1 * sizeof(u32),
-						    &fps->fsr);
+		ret = copy_regset_from_user(child, &ptrace32_view,
+					  REGSET_FP, 0,
+					  33 * sizeof(u32),
+					  fps);
 		break;
 
 	case PTRACE_READTEXT:
@@ -1026,31 +1029,17 @@ long arch_ptrace(struct task_struct *child, long request,
 		break;
 
 	case PTRACE_GETREGS64:
-		ret = copy_regset_to_user(child, view, REGSET_GENERAL,
-					  1 * sizeof(u64),
-					  15 * sizeof(u64),
-					  &pregs->u_regs[0]);
-		if (!ret) {
-			/* XXX doesn't handle 'y' register correctly XXX */
-			ret = copy_regset_to_user(child, view, REGSET_GENERAL,
-						  32 * sizeof(u64),
-						  4 * sizeof(u64),
-						  &pregs->tstate);
-		}
+		ret = copy_regset_to_user(child, &ptrace64_view,
+					  REGSET_GENERAL, 0,
+					  19 * sizeof(u64),
+					  pregs);
 		break;
 
 	case PTRACE_SETREGS64:
-		ret = copy_regset_from_user(child, view, REGSET_GENERAL,
-					    1 * sizeof(u64),
-					    15 * sizeof(u64),
-					    &pregs->u_regs[0]);
-		if (!ret) {
-			/* XXX doesn't handle 'y' register correctly XXX */
-			ret = copy_regset_from_user(child, view, REGSET_GENERAL,
-						    32 * sizeof(u64),
-						    4 * sizeof(u64),
-						    &pregs->tstate);
-		}
+		ret = copy_regset_from_user(child, &ptrace64_view,
+					  REGSET_GENERAL, 0,
+					  19 * sizeof(u64),
+					  pregs);
 		break;
 
 	case PTRACE_GETFPREGS64: