Adding upstream version 4.19.249.upstream/4.19.249

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

1 files changed, 800 insertions, 0 deletions

diff --git a/arch/parisc/kernel/ptrace.c b/arch/parisc/kernel/ptrace.c
new file mode 100644
index 000000000..de2998cb1
--- /dev/null
+++ b/arch/parisc/kernel/ptrace.c
@@ -0,0 +1,800 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Kernel support for the ptrace() and syscall tracing interfaces.
+ *
+ * Copyright (C) 2000 Hewlett-Packard Co, Linuxcare Inc.
+ * Copyright (C) 2000 Matthew Wilcox <matthew@wil.cx>
+ * Copyright (C) 2000 David Huggins-Daines <dhd@debian.org>
+ * Copyright (C) 2008-2016 Helge Deller <deller@gmx.de>
+ */
+
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/elf.h>
+#include <linux/errno.h>
+#include <linux/ptrace.h>
+#include <linux/tracehook.h>
+#include <linux/user.h>
+#include <linux/personality.h>
+#include <linux/regset.h>
+#include <linux/security.h>
+#include <linux/seccomp.h>
+#include <linux/compat.h>
+#include <linux/signal.h>
+#include <linux/audit.h>
+
+#include <linux/uaccess.h>
+#include <asm/pgtable.h>
+#include <asm/processor.h>
+#include <asm/asm-offsets.h>
+
+/* PSW bits we allow the debugger to modify */
+#define USER_PSW_BITS	(PSW_N | PSW_B | PSW_V | PSW_CB)
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/syscalls.h>
+
+/*
+ * These are our native regset flavors.
+ */
+enum parisc_regset {
+	REGSET_GENERAL,
+	REGSET_FP
+};
+
+/*
+ * Called by kernel/ptrace.c when detaching..
+ *
+ * Make sure single step bits etc are not set.
+ */
+void ptrace_disable(struct task_struct *task)
+{
+	clear_tsk_thread_flag(task, TIF_SINGLESTEP);
+	clear_tsk_thread_flag(task, TIF_BLOCKSTEP);
+
+	/* make sure the trap bits are not set */
+	pa_psw(task)->r = 0;
+	pa_psw(task)->t = 0;
+	pa_psw(task)->h = 0;
+	pa_psw(task)->l = 0;
+}
+
+/*
+ * The following functions are called by ptrace_resume() when
+ * enabling or disabling single/block tracing.
+ */
+void user_disable_single_step(struct task_struct *task)
+{
+	ptrace_disable(task);
+}
+
+void user_enable_single_step(struct task_struct *task)
+{
+	clear_tsk_thread_flag(task, TIF_BLOCKSTEP);
+	set_tsk_thread_flag(task, TIF_SINGLESTEP);
+
+	if (pa_psw(task)->n) {
+		/* Nullified, just crank over the queue. */
+		task_regs(task)->iaoq[0] = task_regs(task)->iaoq[1];
+		task_regs(task)->iasq[0] = task_regs(task)->iasq[1];
+		task_regs(task)->iaoq[1] = task_regs(task)->iaoq[0] + 4;
+		pa_psw(task)->n = 0;
+		pa_psw(task)->x = 0;
+		pa_psw(task)->y = 0;
+		pa_psw(task)->z = 0;
+		pa_psw(task)->b = 0;
+		ptrace_disable(task);
+		/* Don't wake up the task, but let the
+		   parent know something happened. */
+		force_sig_fault(SIGTRAP, TRAP_TRACE,
+				(void __user *) (task_regs(task)->iaoq[0] & ~3),
+				task);
+		/* notify_parent(task, SIGCHLD); */
+		return;
+	}
+
+	/* Enable recovery counter traps.  The recovery counter
+	 * itself will be set to zero on a task switch.  If the
+	 * task is suspended on a syscall then the syscall return
+	 * path will overwrite the recovery counter with a suitable
+	 * value such that it traps once back in user space.  We
+	 * disable interrupts in the tasks PSW here also, to avoid
+	 * interrupts while the recovery counter is decrementing.
+	 */
+	pa_psw(task)->r = 1;
+	pa_psw(task)->t = 0;
+	pa_psw(task)->h = 0;
+	pa_psw(task)->l = 0;
+}
+
+void user_enable_block_step(struct task_struct *task)
+{
+	clear_tsk_thread_flag(task, TIF_SINGLESTEP);
+	set_tsk_thread_flag(task, TIF_BLOCKSTEP);
+
+	/* Enable taken branch trap. */
+	pa_psw(task)->r = 0;
+	pa_psw(task)->t = 1;
+	pa_psw(task)->h = 0;
+	pa_psw(task)->l = 0;
+}
+
+long arch_ptrace(struct task_struct *child, long request,
+		 unsigned long addr, unsigned long data)
+{
+	unsigned long __user *datap = (unsigned long __user *)data;
+	unsigned long tmp;
+	long ret = -EIO;
+
+	switch (request) {
+
+	/* Read the word at location addr in the USER area.  For ptraced
+	   processes, the kernel saves all regs on a syscall. */
+	case PTRACE_PEEKUSR:
+		if ((addr & (sizeof(unsigned long)-1)) ||
+		     addr >= sizeof(struct pt_regs))
+			break;
+		tmp = *(unsigned long *) ((char *) task_regs(child) + addr);
+		ret = put_user(tmp, datap);
+		break;
+
+	/* Write the word at location addr in the USER area.  This will need
+	   to change when the kernel no longer saves all regs on a syscall.
+	   FIXME.  There is a problem at the moment in that r3-r18 are only
+	   saved if the process is ptraced on syscall entry, and even then
+	   those values are overwritten by actual register values on syscall
+	   exit. */
+	case PTRACE_POKEUSR:
+		/* Some register values written here may be ignored in
+		 * entry.S:syscall_restore_rfi; e.g. iaoq is written with
+		 * r31/r31+4, and not with the values in pt_regs.
+		 */
+		if (addr == PT_PSW) {
+			/* Allow writing to Nullify, Divide-step-correction,
+			 * and carry/borrow bits.
+			 * BEWARE, if you set N, and then single step, it won't
+			 * stop on the nullified instruction.
+			 */
+			data &= USER_PSW_BITS;
+			task_regs(child)->gr[0] &= ~USER_PSW_BITS;
+			task_regs(child)->gr[0] |= data;
+			ret = 0;
+			break;
+		}
+
+		if ((addr & (sizeof(unsigned long)-1)) ||
+		     addr >= sizeof(struct pt_regs))
+			break;
+		if (addr == PT_IAOQ0 || addr == PT_IAOQ1) {
+			data |= 3; /* ensure userspace privilege */
+		}
+		if ((addr >= PT_GR1 && addr <= PT_GR31) ||
+				addr == PT_IAOQ0 || addr == PT_IAOQ1 ||
+				(addr >= PT_FR0 && addr <= PT_FR31 + 4) ||
+				addr == PT_SAR) {
+			*(unsigned long *) ((char *) task_regs(child) + addr) = data;
+			ret = 0;
+		}
+		break;
+
+	case PTRACE_GETREGS:	/* Get all gp regs from the child. */
+		return copy_regset_to_user(child,
+					   task_user_regset_view(current),
+					   REGSET_GENERAL,
+					   0, sizeof(struct user_regs_struct),
+					   datap);
+
+	case PTRACE_SETREGS:	/* Set all gp regs in the child. */
+		return copy_regset_from_user(child,
+					     task_user_regset_view(current),
+					     REGSET_GENERAL,
+					     0, sizeof(struct user_regs_struct),
+					     datap);
+
+	case PTRACE_GETFPREGS:	/* Get the child FPU state. */
+		return copy_regset_to_user(child,
+					   task_user_regset_view(current),
+					   REGSET_FP,
+					   0, sizeof(struct user_fp_struct),
+					   datap);
+
+	case PTRACE_SETFPREGS:	/* Set the child FPU state. */
+		return copy_regset_from_user(child,
+					     task_user_regset_view(current),
+					     REGSET_FP,
+					     0, sizeof(struct user_fp_struct),
+					     datap);
+
+	default:
+		ret = ptrace_request(child, request, addr, data);
+		break;
+	}
+
+	return ret;
+}
+
+
+#ifdef CONFIG_COMPAT
+
+/* This function is needed to translate 32 bit pt_regs offsets in to
+ * 64 bit pt_regs offsets.  For example, a 32 bit gdb under a 64 bit kernel
+ * will request offset 12 if it wants gr3, but the lower 32 bits of
+ * the 64 bit kernels view of gr3 will be at offset 28 (3*8 + 4).
+ * This code relies on a 32 bit pt_regs being comprised of 32 bit values
+ * except for the fp registers which (a) are 64 bits, and (b) follow
+ * the gr registers at the start of pt_regs.  The 32 bit pt_regs should
+ * be half the size of the 64 bit pt_regs, plus 32*4 to allow for fr[]
+ * being 64 bit in both cases.
+ */
+
+static compat_ulong_t translate_usr_offset(compat_ulong_t offset)
+{
+	compat_ulong_t pos;
+
+	if (offset < 32*4)	/* gr[0..31] */
+		pos = offset * 2 + 4;
+	else if (offset < 32*4+32*8)	/* fr[0] ... fr[31] */
+		pos = (offset - 32*4) + PT_FR0;
+	else if (offset < sizeof(struct pt_regs)/2 + 32*4) /* sr[0] ... ipsw */
+		pos = (offset - 32*4 - 32*8) * 2 + PT_SR0 + 4;
+	else
+		pos = sizeof(struct pt_regs);
+
+	return pos;
+}
+
+long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
+			compat_ulong_t addr, compat_ulong_t data)
+{
+	compat_uint_t tmp;
+	long ret = -EIO;
+
+	switch (request) {
+
+	case PTRACE_PEEKUSR:
+		if (addr & (sizeof(compat_uint_t)-1))
+			break;
+		addr = translate_usr_offset(addr);
+		if (addr >= sizeof(struct pt_regs))
+			break;
+
+		tmp = *(compat_uint_t *) ((char *) task_regs(child) + addr);
+		ret = put_user(tmp, (compat_uint_t *) (unsigned long) data);
+		break;
+
+	/* Write the word at location addr in the USER area.  This will need
+	   to change when the kernel no longer saves all regs on a syscall.
+	   FIXME.  There is a problem at the moment in that r3-r18 are only
+	   saved if the process is ptraced on syscall entry, and even then
+	   those values are overwritten by actual register values on syscall
+	   exit. */
+	case PTRACE_POKEUSR:
+		/* Some register values written here may be ignored in
+		 * entry.S:syscall_restore_rfi; e.g. iaoq is written with
+		 * r31/r31+4, and not with the values in pt_regs.
+		 */
+		if (addr == PT_PSW) {
+			/* Since PT_PSW==0, it is valid for 32 bit processes
+			 * under 64 bit kernels as well.
+			 */
+			ret = arch_ptrace(child, request, addr, data);
+		} else {
+			if (addr & (sizeof(compat_uint_t)-1))
+				break;
+			addr = translate_usr_offset(addr);
+			if (addr >= sizeof(struct pt_regs))
+				break;
+			if (addr == PT_IAOQ0+4 || addr == PT_IAOQ1+4) {
+				data |= 3; /* ensure userspace privilege */
+			}
+			if (addr >= PT_FR0 && addr <= PT_FR31 + 4) {
+				/* Special case, fp regs are 64 bits anyway */
+				*(__u32 *) ((char *) task_regs(child) + addr) = data;
+				ret = 0;
+			}
+			else if ((addr >= PT_GR1+4 && addr <= PT_GR31+4) ||
+					addr == PT_IAOQ0+4 || addr == PT_IAOQ1+4 ||
+					addr == PT_SAR+4) {
+				/* Zero the top 32 bits */
+				*(__u32 *) ((char *) task_regs(child) + addr - 4) = 0;
+				*(__u32 *) ((char *) task_regs(child) + addr) = data;
+				ret = 0;
+			}
+		}
+		break;
+
+	default:
+		ret = compat_ptrace_request(child, request, addr, data);
+		break;
+	}
+
+	return ret;
+}
+#endif
+
+long do_syscall_trace_enter(struct pt_regs *regs)
+{
+	if (test_thread_flag(TIF_SYSCALL_TRACE)) {
+		int rc = tracehook_report_syscall_entry(regs);
+
+		/*
+		 * As tracesys_next does not set %r28 to -ENOSYS
+		 * when %r20 is set to -1, initialize it here.
+		 */
+		regs->gr[28] = -ENOSYS;
+
+		if (rc) {
+			/*
+			 * A nonzero return code from
+			 * tracehook_report_syscall_entry() tells us
+			 * to prevent the syscall execution.  Skip
+			 * the syscall call and the syscall restart handling.
+			 *
+			 * Note that the tracer may also just change
+			 * regs->gr[20] to an invalid syscall number,
+			 * that is handled by tracesys_next.
+			 */
+			regs->gr[20] = -1UL;
+			return -1;
+		}
+	}
+
+	/* Do the secure computing check after ptrace. */
+	if (secure_computing(NULL) == -1)
+		return -1;
+
+#ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
+	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
+		trace_sys_enter(regs, regs->gr[20]);
+#endif
+
+#ifdef CONFIG_64BIT
+	if (!is_compat_task())
+		audit_syscall_entry(regs->gr[20], regs->gr[26], regs->gr[25],
+				    regs->gr[24], regs->gr[23]);
+	else
+#endif
+		audit_syscall_entry(regs->gr[20] & 0xffffffff,
+			regs->gr[26] & 0xffffffff,
+			regs->gr[25] & 0xffffffff,
+			regs->gr[24] & 0xffffffff,
+			regs->gr[23] & 0xffffffff);
+
+	/*
+	 * Sign extend the syscall number to 64bit since it may have been
+	 * modified by a compat ptrace call
+	 */
+	return (int) ((u32) regs->gr[20]);
+}
+
+void do_syscall_trace_exit(struct pt_regs *regs)
+{
+	int stepping = test_thread_flag(TIF_SINGLESTEP) ||
+		test_thread_flag(TIF_BLOCKSTEP);
+
+	audit_syscall_exit(regs);
+
+#ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
+	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
+		trace_sys_exit(regs, regs->gr[20]);
+#endif
+
+	if (stepping || test_thread_flag(TIF_SYSCALL_TRACE))
+		tracehook_report_syscall_exit(regs, stepping);
+}
+
+
+/*
+ * regset functions.
+ */
+
+static int fpr_get(struct task_struct *target,
+		     const struct user_regset *regset,
+		     unsigned int pos, unsigned int count,
+		     void *kbuf, void __user *ubuf)
+{
+	struct pt_regs *regs = task_regs(target);
+	__u64 *k = kbuf;
+	__u64 __user *u = ubuf;
+	__u64 reg;
+
+	pos /= sizeof(reg);
+	count /= sizeof(reg);
+
+	if (kbuf)
+		for (; count > 0 && pos < ELF_NFPREG; --count)
+			*k++ = regs->fr[pos++];
+	else
+		for (; count > 0 && pos < ELF_NFPREG; --count)
+			if (__put_user(regs->fr[pos++], u++))
+				return -EFAULT;
+
+	kbuf = k;
+	ubuf = u;
+	pos *= sizeof(reg);
+	count *= sizeof(reg);
+	return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
+					ELF_NFPREG * sizeof(reg), -1);
+}
+
+static int fpr_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_regs(target);
+	const __u64 *k = kbuf;
+	const __u64 __user *u = ubuf;
+	__u64 reg;
+
+	pos /= sizeof(reg);
+	count /= sizeof(reg);
+
+	if (kbuf)
+		for (; count > 0 && pos < ELF_NFPREG; --count)
+			regs->fr[pos++] = *k++;
+	else
+		for (; count > 0 && pos < ELF_NFPREG; --count) {
+			if (__get_user(reg, u++))
+				return -EFAULT;
+			regs->fr[pos++] = reg;
+		}
+
+	kbuf = k;
+	ubuf = u;
+	pos *= sizeof(reg);
+	count *= sizeof(reg);
+	return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
+					 ELF_NFPREG * sizeof(reg), -1);
+}
+
+#define RI(reg) (offsetof(struct user_regs_struct,reg) / sizeof(long))
+
+static unsigned long get_reg(struct pt_regs *regs, int num)
+{
+	switch (num) {
+	case RI(gr[0]) ... RI(gr[31]):	return regs->gr[num - RI(gr[0])];
+	case RI(sr[0]) ... RI(sr[7]):	return regs->sr[num - RI(sr[0])];
+	case RI(iasq[0]):		return regs->iasq[0];
+	case RI(iasq[1]):		return regs->iasq[1];
+	case RI(iaoq[0]):		return regs->iaoq[0];
+	case RI(iaoq[1]):		return regs->iaoq[1];
+	case RI(sar):			return regs->sar;
+	case RI(iir):			return regs->iir;
+	case RI(isr):			return regs->isr;
+	case RI(ior):			return regs->ior;
+	case RI(ipsw):			return regs->ipsw;
+	case RI(cr27):			return regs->cr27;
+	case RI(cr0):			return mfctl(0);
+	case RI(cr24):			return mfctl(24);
+	case RI(cr25):			return mfctl(25);
+	case RI(cr26):			return mfctl(26);
+	case RI(cr28):			return mfctl(28);
+	case RI(cr29):			return mfctl(29);
+	case RI(cr30):			return mfctl(30);
+	case RI(cr31):			return mfctl(31);
+	case RI(cr8):			return mfctl(8);
+	case RI(cr9):			return mfctl(9);
+	case RI(cr12):			return mfctl(12);
+	case RI(cr13):			return mfctl(13);
+	case RI(cr10):			return mfctl(10);
+	case RI(cr15):			return mfctl(15);
+	default:			return 0;
+	}
+}
+
+static void set_reg(struct pt_regs *regs, int num, unsigned long val)
+{
+	switch (num) {
+	case RI(gr[0]): /*
+			 * PSW is in gr[0].
+			 * Allow writing to Nullify, Divide-step-correction,
+			 * and carry/borrow bits.
+			 * BEWARE, if you set N, and then single step, it won't
+			 * stop on the nullified instruction.
+			 */
+			val &= USER_PSW_BITS;
+			regs->gr[0] &= ~USER_PSW_BITS;
+			regs->gr[0] |= val;
+			return;
+	case RI(gr[1]) ... RI(gr[31]):
+			regs->gr[num - RI(gr[0])] = val;
+			return;
+	case RI(iaoq[0]):
+	case RI(iaoq[1]):
+			/* set 2 lowest bits to ensure userspace privilege: */
+			regs->iaoq[num - RI(iaoq[0])] = val | 3;
+			return;
+	case RI(sar):	regs->sar = val;
+			return;
+	default:	return;
+#if 0
+	/* do not allow to change any of the following registers (yet) */
+	case RI(sr[0]) ... RI(sr[7]):	return regs->sr[num - RI(sr[0])];
+	case RI(iasq[0]):		return regs->iasq[0];
+	case RI(iasq[1]):		return regs->iasq[1];
+	case RI(iir):			return regs->iir;
+	case RI(isr):			return regs->isr;
+	case RI(ior):			return regs->ior;
+	case RI(ipsw):			return regs->ipsw;
+	case RI(cr27):			return regs->cr27;
+        case cr0, cr24, cr25, cr26, cr27, cr28, cr29, cr30, cr31;
+        case cr8, cr9, cr12, cr13, cr10, cr15;
+#endif
+	}
+}
+
+static int gpr_get(struct task_struct *target,
+		     const struct user_regset *regset,
+		     unsigned int pos, unsigned int count,
+		     void *kbuf, void __user *ubuf)
+{
+	struct pt_regs *regs = task_regs(target);
+	unsigned long *k = kbuf;
+	unsigned long __user *u = ubuf;
+	unsigned long reg;
+
+	pos /= sizeof(reg);
+	count /= sizeof(reg);
+
+	if (kbuf)
+		for (; count > 0 && pos < ELF_NGREG; --count)
+			*k++ = get_reg(regs, pos++);
+	else
+		for (; count > 0 && pos < ELF_NGREG; --count)
+			if (__put_user(get_reg(regs, pos++), u++))
+				return -EFAULT;
+	kbuf = k;
+	ubuf = u;
+	pos *= sizeof(reg);
+	count *= sizeof(reg);
+	return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
+					ELF_NGREG * sizeof(reg), -1);
+}
+
+static int gpr_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_regs(target);
+	const unsigned long *k = kbuf;
+	const unsigned long __user *u = ubuf;
+	unsigned long reg;
+
+	pos /= sizeof(reg);
+	count /= sizeof(reg);
+
+	if (kbuf)
+		for (; count > 0 && pos < ELF_NGREG; --count)
+			set_reg(regs, pos++, *k++);
+	else
+		for (; count > 0 && pos < ELF_NGREG; --count) {
+			if (__get_user(reg, u++))
+				return -EFAULT;
+			set_reg(regs, pos++, reg);
+		}
+
+	kbuf = k;
+	ubuf = u;
+	pos *= sizeof(reg);
+	count *= sizeof(reg);
+	return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
+					 ELF_NGREG * sizeof(reg), -1);
+}
+
+static const struct user_regset native_regsets[] = {
+	[REGSET_GENERAL] = {
+		.core_note_type = NT_PRSTATUS, .n = ELF_NGREG,
+		.size = sizeof(long), .align = sizeof(long),
+		.get = gpr_get, .set = gpr_set
+	},
+	[REGSET_FP] = {
+		.core_note_type = NT_PRFPREG, .n = ELF_NFPREG,
+		.size = sizeof(__u64), .align = sizeof(__u64),
+		.get = fpr_get, .set = fpr_set
+	}
+};
+
+static const struct user_regset_view user_parisc_native_view = {
+	.name = "parisc", .e_machine = ELF_ARCH, .ei_osabi = ELFOSABI_LINUX,
+	.regsets = native_regsets, .n = ARRAY_SIZE(native_regsets)
+};
+
+#ifdef CONFIG_64BIT
+#include <linux/compat.h>
+
+static int gpr32_get(struct task_struct *target,
+		     const struct user_regset *regset,
+		     unsigned int pos, unsigned int count,
+		     void *kbuf, void __user *ubuf)
+{
+	struct pt_regs *regs = task_regs(target);
+	compat_ulong_t *k = kbuf;
+	compat_ulong_t __user *u = ubuf;
+	compat_ulong_t reg;
+
+	pos /= sizeof(reg);
+	count /= sizeof(reg);
+
+	if (kbuf)
+		for (; count > 0 && pos < ELF_NGREG; --count)
+			*k++ = get_reg(regs, pos++);
+	else
+		for (; count > 0 && pos < ELF_NGREG; --count)
+			if (__put_user((compat_ulong_t) get_reg(regs, pos++), u++))
+				return -EFAULT;
+
+	kbuf = k;
+	ubuf = u;
+	pos *= sizeof(reg);
+	count *= sizeof(reg);
+	return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
+					ELF_NGREG * sizeof(reg), -1);
+}
+
+static int gpr32_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_regs(target);
+	const compat_ulong_t *k = kbuf;
+	const compat_ulong_t __user *u = ubuf;
+	compat_ulong_t reg;
+
+	pos /= sizeof(reg);
+	count /= sizeof(reg);
+
+	if (kbuf)
+		for (; count > 0 && pos < ELF_NGREG; --count)
+			set_reg(regs, pos++, *k++);
+	else
+		for (; count > 0 && pos < ELF_NGREG; --count) {
+			if (__get_user(reg, u++))
+				return -EFAULT;
+			set_reg(regs, pos++, reg);
+		}
+
+	kbuf = k;
+	ubuf = u;
+	pos *= sizeof(reg);
+	count *= sizeof(reg);
+	return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
+					 ELF_NGREG * sizeof(reg), -1);
+}
+
+/*
+ * These are the regset flavors matching the 32bit native set.
+ */
+static const struct user_regset compat_regsets[] = {
+	[REGSET_GENERAL] = {
+		.core_note_type = NT_PRSTATUS, .n = ELF_NGREG,
+		.size = sizeof(compat_long_t), .align = sizeof(compat_long_t),
+		.get = gpr32_get, .set = gpr32_set
+	},
+	[REGSET_FP] = {
+		.core_note_type = NT_PRFPREG, .n = ELF_NFPREG,
+		.size = sizeof(__u64), .align = sizeof(__u64),
+		.get = fpr_get, .set = fpr_set
+	}
+};
+
+static const struct user_regset_view user_parisc_compat_view = {
+	.name = "parisc", .e_machine = EM_PARISC, .ei_osabi = ELFOSABI_LINUX,
+	.regsets = compat_regsets, .n = ARRAY_SIZE(compat_regsets)
+};
+#endif	/* CONFIG_64BIT */
+
+const struct user_regset_view *task_user_regset_view(struct task_struct *task)
+{
+	BUILD_BUG_ON(sizeof(struct user_regs_struct)/sizeof(long) != ELF_NGREG);
+	BUILD_BUG_ON(sizeof(struct user_fp_struct)/sizeof(__u64) != ELF_NFPREG);
+#ifdef CONFIG_64BIT
+	if (is_compat_task())
+		return &user_parisc_compat_view;
+#endif
+	return &user_parisc_native_view;
+}
+
+
+/* HAVE_REGS_AND_STACK_ACCESS_API feature */
+
+struct pt_regs_offset {
+	const char *name;
+	int offset;
+};
+
+#define REG_OFFSET_NAME(r)    {.name = #r, .offset = offsetof(struct pt_regs, r)}
+#define REG_OFFSET_INDEX(r,i) {.name = #r#i, .offset = offsetof(struct pt_regs, r[i])}
+#define REG_OFFSET_END {.name = NULL, .offset = 0}
+
+static const struct pt_regs_offset regoffset_table[] = {
+	REG_OFFSET_INDEX(gr,0),
+	REG_OFFSET_INDEX(gr,1),
+	REG_OFFSET_INDEX(gr,2),
+	REG_OFFSET_INDEX(gr,3),
+	REG_OFFSET_INDEX(gr,4),
+	REG_OFFSET_INDEX(gr,5),
+	REG_OFFSET_INDEX(gr,6),
+	REG_OFFSET_INDEX(gr,7),
+	REG_OFFSET_INDEX(gr,8),
+	REG_OFFSET_INDEX(gr,9),
+	REG_OFFSET_INDEX(gr,10),
+	REG_OFFSET_INDEX(gr,11),
+	REG_OFFSET_INDEX(gr,12),
+	REG_OFFSET_INDEX(gr,13),
+	REG_OFFSET_INDEX(gr,14),
+	REG_OFFSET_INDEX(gr,15),
+	REG_OFFSET_INDEX(gr,16),
+	REG_OFFSET_INDEX(gr,17),
+	REG_OFFSET_INDEX(gr,18),
+	REG_OFFSET_INDEX(gr,19),
+	REG_OFFSET_INDEX(gr,20),
+	REG_OFFSET_INDEX(gr,21),
+	REG_OFFSET_INDEX(gr,22),
+	REG_OFFSET_INDEX(gr,23),
+	REG_OFFSET_INDEX(gr,24),
+	REG_OFFSET_INDEX(gr,25),
+	REG_OFFSET_INDEX(gr,26),
+	REG_OFFSET_INDEX(gr,27),
+	REG_OFFSET_INDEX(gr,28),
+	REG_OFFSET_INDEX(gr,29),
+	REG_OFFSET_INDEX(gr,30),
+	REG_OFFSET_INDEX(gr,31),
+	REG_OFFSET_INDEX(sr,0),
+	REG_OFFSET_INDEX(sr,1),
+	REG_OFFSET_INDEX(sr,2),
+	REG_OFFSET_INDEX(sr,3),
+	REG_OFFSET_INDEX(sr,4),
+	REG_OFFSET_INDEX(sr,5),
+	REG_OFFSET_INDEX(sr,6),
+	REG_OFFSET_INDEX(sr,7),
+	REG_OFFSET_INDEX(iasq,0),
+	REG_OFFSET_INDEX(iasq,1),
+	REG_OFFSET_INDEX(iaoq,0),
+	REG_OFFSET_INDEX(iaoq,1),
+	REG_OFFSET_NAME(cr27),
+	REG_OFFSET_NAME(ksp),
+	REG_OFFSET_NAME(kpc),
+	REG_OFFSET_NAME(sar),
+	REG_OFFSET_NAME(iir),
+	REG_OFFSET_NAME(isr),
+	REG_OFFSET_NAME(ior),
+	REG_OFFSET_NAME(ipsw),
+	REG_OFFSET_END,
+};
+
+/**
+ * regs_query_register_offset() - query register offset from its name
+ * @name:	the name of a register
+ *
+ * regs_query_register_offset() returns the offset of a register in struct
+ * pt_regs from its name. If the name is invalid, this returns -EINVAL;
+ */
+int regs_query_register_offset(const char *name)
+{
+	const struct pt_regs_offset *roff;
+	for (roff = regoffset_table; roff->name != NULL; roff++)
+		if (!strcmp(roff->name, name))
+			return roff->offset;
+	return -EINVAL;
+}
+
+/**
+ * regs_query_register_name() - query register name from its offset
+ * @offset:	the offset of a register in struct pt_regs.
+ *
+ * regs_query_register_name() returns the name of a register from its
+ * offset in struct pt_regs. If the @offset is invalid, this returns NULL;
+ */
+const char *regs_query_register_name(unsigned int offset)
+{
+	const struct pt_regs_offset *roff;
+	for (roff = regoffset_table; roff->name != NULL; roff++)
+		if (roff->offset == offset)
+			return roff->name;
+	return NULL;
+}