[IA64] regset: 64-bit support

This is the 64-bit regset implementation under IA64. Basically register
read/write, which is derived from current ptrace register read/write.

Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

arch/ia64/kernel/ptrace.c

@@ -3,6 +3,9 @@
  *
  * Copyright (C) 1999-2005 Hewlett-Packard Co
  *	David Mosberger-Tang <davidm@hpl.hp.com>
+ * Copyright (C) 2006 Intel Co
+ *  2006-08-12	- IA64 Native Utrace implementation support added by
+ *	Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
  *
  * Derived from the x86 and Alpha versions.
  */
@@ -17,6 +20,8 @@
 #include <linux/security.h>
 #include <linux/audit.h>
 #include <linux/signal.h>
+#include <linux/regset.h>
+#include <linux/elf.h>
 
 #include <asm/pgtable.h>
 #include <asm/processor.h>
@@ -1626,3 +1631,688 @@ syscall_trace_leave (long arg0, long arg1, long arg2, long arg3,
 	if (test_thread_flag(TIF_RESTORE_RSE))
 		ia64_sync_krbs();
 }
+
+/* Utrace implementation starts here */
+struct regset_get {
+	void *kbuf;
+	void __user *ubuf;
+};
+
+struct regset_set {
+	const void *kbuf;
+	const void __user *ubuf;
+};
+
+struct regset_getset {
+	struct task_struct *target;
+	const struct user_regset *regset;
+	union {
+		struct regset_get get;
+		struct regset_set set;
+	} u;
+	unsigned int pos;
+	unsigned int count;
+	int ret;
+};
+
+static int
+access_elf_gpreg(struct task_struct *target, struct unw_frame_info *info,
+		unsigned long addr, unsigned long *data, int write_access)
+{
+	struct pt_regs *pt;
+	unsigned long *ptr = NULL;
+	int ret;
+	char nat = 0;
+
+	pt = task_pt_regs(target);
+	switch (addr) {
+	case ELF_GR_OFFSET(1):
+		ptr = &pt->r1;
+		break;
+	case ELF_GR_OFFSET(2):
+	case ELF_GR_OFFSET(3):
+		ptr = (void *)&pt->r2 + (addr - ELF_GR_OFFSET(2));
+		break;
+	case ELF_GR_OFFSET(4) ... ELF_GR_OFFSET(7):
+		if (write_access) {
+			/* read NaT bit first: */
+			unsigned long dummy;
+
+			ret = unw_get_gr(info, addr/8, &dummy, &nat);
+			if (ret < 0)
+				return ret;
+		}
+		return unw_access_gr(info, addr/8, data, &nat, write_access);
+	case ELF_GR_OFFSET(8) ... ELF_GR_OFFSET(11):
+		ptr = (void *)&pt->r8 + addr - ELF_GR_OFFSET(8);
+		break;
+	case ELF_GR_OFFSET(12):
+	case ELF_GR_OFFSET(13):
+		ptr = (void *)&pt->r12 + addr - ELF_GR_OFFSET(12);
+		break;
+	case ELF_GR_OFFSET(14):
+		ptr = &pt->r14;
+		break;
+	case ELF_GR_OFFSET(15):
+		ptr = &pt->r15;
+	}
+	if (write_access)
+		*ptr = *data;
+	else
+		*data = *ptr;
+	return 0;
+}
+
+static int
+access_elf_breg(struct task_struct *target, struct unw_frame_info *info,
+		unsigned long addr, unsigned long *data, int write_access)
+{
+	struct pt_regs *pt;
+	unsigned long *ptr = NULL;
+
+	pt = task_pt_regs(target);
+	switch (addr) {
+	case ELF_BR_OFFSET(0):
+		ptr = &pt->b0;
+		break;
+	case ELF_BR_OFFSET(1) ... ELF_BR_OFFSET(5):
+		return unw_access_br(info, (addr - ELF_BR_OFFSET(0))/8,
+				     data, write_access);
+	case ELF_BR_OFFSET(6):
+		ptr = &pt->b6;
+		break;
+	case ELF_BR_OFFSET(7):
+		ptr = &pt->b7;
+	}
+	if (write_access)
+		*ptr = *data;
+	else
+		*data = *ptr;
+	return 0;
+}
+
+static int
+access_elf_areg(struct task_struct *target, struct unw_frame_info *info,
+		unsigned long addr, unsigned long *data, int write_access)
+{
+	struct pt_regs *pt;
+	unsigned long cfm, urbs_end;
+	unsigned long *ptr = NULL;
+
+	pt = task_pt_regs(target);
+	if (addr >= ELF_AR_RSC_OFFSET && addr <= ELF_AR_SSD_OFFSET) {
+		switch (addr) {
+		case ELF_AR_RSC_OFFSET:
+			/* force PL3 */
+			if (write_access)
+				pt->ar_rsc = *data | (3 << 2);
+			else
+				*data = pt->ar_rsc;
+			return 0;
+		case ELF_AR_BSP_OFFSET:
+			/*
+			 * By convention, we use PT_AR_BSP to refer to
+			 * the end of the user-level backing store.
+			 * Use ia64_rse_skip_regs(PT_AR_BSP, -CFM.sof)
+			 * to get the real value of ar.bsp at the time
+			 * the kernel was entered.
+			 *
+			 * Furthermore, when changing the contents of
+			 * PT_AR_BSP (or PT_CFM) while the task is
+			 * blocked in a system call, convert the state
+			 * so that the non-system-call exit
+			 * path is used.  This ensures that the proper
+			 * state will be picked up when resuming
+			 * execution.  However, it *also* means that
+			 * once we write PT_AR_BSP/PT_CFM, it won't be
+			 * possible to modify the syscall arguments of
+			 * the pending system call any longer.  This
+			 * shouldn't be an issue because modifying
+			 * PT_AR_BSP/PT_CFM generally implies that
+			 * we're either abandoning the pending system
+			 * call or that we defer it's re-execution
+			 * (e.g., due to GDB doing an inferior
+			 * function call).
+			 */
+			urbs_end = ia64_get_user_rbs_end(target, pt, &cfm);
+			if (write_access) {
+				if (*data != urbs_end) {
+					if (in_syscall(pt))
+						convert_to_non_syscall(target,
+								       pt,
+								       cfm);
+					/*
+					 * Simulate user-level write
+					 * of ar.bsp:
+					 */
+					pt->loadrs = 0;
+					pt->ar_bspstore = *data;
+				}
+			} else
+				*data = urbs_end;
+			return 0;
+		case ELF_AR_BSPSTORE_OFFSET:
+			ptr = &pt->ar_bspstore;
+			break;
+		case ELF_AR_RNAT_OFFSET:
+			ptr = &pt->ar_rnat;
+			break;
+		case ELF_AR_CCV_OFFSET:
+			ptr = &pt->ar_ccv;
+			break;
+		case ELF_AR_UNAT_OFFSET:
+			ptr = &pt->ar_unat;
+			break;
+		case ELF_AR_FPSR_OFFSET:
+			ptr = &pt->ar_fpsr;
+			break;
+		case ELF_AR_PFS_OFFSET:
+			ptr = &pt->ar_pfs;
+			break;
+		case ELF_AR_LC_OFFSET:
+			return unw_access_ar(info, UNW_AR_LC, data,
+					     write_access);
+		case ELF_AR_EC_OFFSET:
+			return unw_access_ar(info, UNW_AR_EC, data,
+					     write_access);
+		case ELF_AR_CSD_OFFSET:
+			ptr = &pt->ar_csd;
+			break;
+		case ELF_AR_SSD_OFFSET:
+			ptr = &pt->ar_ssd;
+		}
+	} else if (addr >= ELF_CR_IIP_OFFSET && addr <= ELF_CR_IPSR_OFFSET) {
+		switch (addr) {
+		case ELF_CR_IIP_OFFSET:
+			ptr = &pt->cr_iip;
+			break;
+		case ELF_CFM_OFFSET:
+			urbs_end = ia64_get_user_rbs_end(target, pt, &cfm);
+			if (write_access) {
+				if (((cfm ^ *data) & PFM_MASK) != 0) {
+					if (in_syscall(pt))
+						convert_to_non_syscall(target,
+								       pt,
+								       cfm);
+					pt->cr_ifs = ((pt->cr_ifs & ~PFM_MASK)
+						      | (*data & PFM_MASK));
+				}
+			} else
+				*data = cfm;
+			return 0;
+		case ELF_CR_IPSR_OFFSET:
+			if (write_access) {
+				unsigned long tmp = *data;
+				/* psr.ri==3 is a reserved value: SDM 2:25 */
+				if ((tmp & IA64_PSR_RI) == IA64_PSR_RI)
+					tmp &= ~IA64_PSR_RI;
+				pt->cr_ipsr = ((tmp & IPSR_MASK)
+					       | (pt->cr_ipsr & ~IPSR_MASK));
+			} else
+				*data = (pt->cr_ipsr & IPSR_MASK);
+			return 0;
+		}
+	} else if (addr == ELF_NAT_OFFSET)
+		return access_nat_bits(target, pt, info,
+				       data, write_access);
+	else if (addr == ELF_PR_OFFSET)
+		ptr = &pt->pr;
+	else
+		return -1;
+
+	if (write_access)
+		*ptr = *data;
+	else
+		*data = *ptr;
+
+	return 0;
+}
+
+static int
+access_elf_reg(struct task_struct *target, struct unw_frame_info *info,
+		unsigned long addr, unsigned long *data, int write_access)
+{
+	if (addr >= ELF_GR_OFFSET(1) && addr <= ELF_GR_OFFSET(15))
+		return access_elf_gpreg(target, info, addr, data, write_access);
+	else if (addr >= ELF_BR_OFFSET(0) && addr <= ELF_BR_OFFSET(7))
+		return access_elf_breg(target, info, addr, data, write_access);
+	else
+		return access_elf_areg(target, info, addr, data, write_access);
+}
+
+void do_gpregs_get(struct unw_frame_info *info, void *arg)
+{
+	struct pt_regs *pt;
+	struct regset_getset *dst = arg;
+	elf_greg_t tmp[16];
+	unsigned int i, index, min_copy;
+
+	if (unw_unwind_to_user(info) < 0)
+		return;
+
+	/*
+	 * coredump format:
+	 *      r0-r31
+	 *      NaT bits (for r0-r31; bit N == 1 iff rN is a NaT)
+	 *      predicate registers (p0-p63)
+	 *      b0-b7
+	 *      ip cfm user-mask
+	 *      ar.rsc ar.bsp ar.bspstore ar.rnat
+	 *      ar.ccv ar.unat ar.fpsr ar.pfs ar.lc ar.ec
+	 */
+
+
+	/* Skip r0 */
+	if (dst->count > 0 && dst->pos < ELF_GR_OFFSET(1)) {
+		dst->ret = user_regset_copyout_zero(&dst->pos, &dst->count,
+						      &dst->u.get.kbuf,
+						      &dst->u.get.ubuf,
+						      0, ELF_GR_OFFSET(1));
+		if (dst->ret || dst->count == 0)
+			return;
+	}
+
+	/* gr1 - gr15 */
+	if (dst->count > 0 && dst->pos < ELF_GR_OFFSET(16)) {
+		index = (dst->pos - ELF_GR_OFFSET(1)) / sizeof(elf_greg_t);
+		min_copy = ELF_GR_OFFSET(16) > (dst->pos + dst->count) ?
+			 (dst->pos + dst->count) : ELF_GR_OFFSET(16);
+		for (i = dst->pos; i < min_copy; i += sizeof(elf_greg_t),
+				index++)
+			if (access_elf_reg(dst->target, info, i,
+						&tmp[index], 0) < 0) {
+				dst->ret = -EIO;
+				return;
+			}
+		dst->ret = user_regset_copyout(&dst->pos, &dst->count,
+				&dst->u.get.kbuf, &dst->u.get.ubuf, tmp,
+				ELF_GR_OFFSET(1), ELF_GR_OFFSET(16));
+		if (dst->ret || dst->count == 0)
+			return;
+	}
+
+	/* r16-r31 */
+	if (dst->count > 0 && dst->pos < ELF_NAT_OFFSET) {
+		pt = task_pt_regs(dst->target);
+		dst->ret = user_regset_copyout(&dst->pos, &dst->count,
+				&dst->u.get.kbuf, &dst->u.get.ubuf, &pt->r16,
+				ELF_GR_OFFSET(16), ELF_NAT_OFFSET);
+		if (dst->ret || dst->count == 0)
+			return;
+	}
+
+	/* nat, pr, b0 - b7 */
+	if (dst->count > 0 && dst->pos < ELF_CR_IIP_OFFSET) {
+		index = (dst->pos - ELF_NAT_OFFSET) / sizeof(elf_greg_t);
+		min_copy = ELF_CR_IIP_OFFSET > (dst->pos + dst->count) ?
+			 (dst->pos + dst->count) : ELF_CR_IIP_OFFSET;
+		for (i = dst->pos; i < min_copy; i += sizeof(elf_greg_t),
+				index++)
+			if (access_elf_reg(dst->target, info, i,
+						&tmp[index], 0) < 0) {
+				dst->ret = -EIO;
+				return;
+			}
+		dst->ret = user_regset_copyout(&dst->pos, &dst->count,
+				&dst->u.get.kbuf, &dst->u.get.ubuf, tmp,
+				ELF_NAT_OFFSET, ELF_CR_IIP_OFFSET);
+		if (dst->ret || dst->count == 0)
+			return;
+	}
+
+	/* ip cfm psr ar.rsc ar.bsp ar.bspstore ar.rnat
+	 * ar.ccv ar.unat ar.fpsr ar.pfs ar.lc ar.ec ar.csd ar.ssd
+	 */
+	if (dst->count > 0 && dst->pos < (ELF_AR_END_OFFSET)) {
+		index = (dst->pos - ELF_CR_IIP_OFFSET) / sizeof(elf_greg_t);
+		min_copy = ELF_AR_END_OFFSET > (dst->pos + dst->count) ?
+			 (dst->pos + dst->count) : ELF_AR_END_OFFSET;
+		for (i = dst->pos; i < min_copy; i += sizeof(elf_greg_t),
+				index++)
+			if (access_elf_reg(dst->target, info, i,
+						&tmp[index], 0) < 0) {
+				dst->ret = -EIO;
+				return;
+			}
+		dst->ret = user_regset_copyout(&dst->pos, &dst->count,
+				&dst->u.get.kbuf, &dst->u.get.ubuf, tmp,
+				ELF_CR_IIP_OFFSET, ELF_AR_END_OFFSET);
+	}
+}
+
+void do_gpregs_set(struct unw_frame_info *info, void *arg)
+{
+	struct pt_regs *pt;
+	struct regset_getset *dst = arg;
+	elf_greg_t tmp[16];
+	unsigned int i, index;
+
+	if (unw_unwind_to_user(info) < 0)
+		return;
+
+	/* Skip r0 */
+	if (dst->count > 0 && dst->pos < ELF_GR_OFFSET(1)) {
+		dst->ret = user_regset_copyin_ignore(&dst->pos, &dst->count,
+						       &dst->u.set.kbuf,
+						       &dst->u.set.ubuf,
+						       0, ELF_GR_OFFSET(1));
+		if (dst->ret || dst->count == 0)
+			return;
+	}
+
+	/* gr1-gr15 */
+	if (dst->count > 0 && dst->pos < ELF_GR_OFFSET(16)) {
+		i = dst->pos;
+		index = (dst->pos - ELF_GR_OFFSET(1)) / sizeof(elf_greg_t);
+		dst->ret = user_regset_copyin(&dst->pos, &dst->count,
+				&dst->u.set.kbuf, &dst->u.set.ubuf, tmp,
+				ELF_GR_OFFSET(1), ELF_GR_OFFSET(16));
+		if (dst->ret)
+			return;
+		for ( ; i < dst->pos; i += sizeof(elf_greg_t), index++)
+			if (access_elf_reg(dst->target, info, i,
+						&tmp[index], 1) < 0) {
+				dst->ret = -EIO;
+				return;
+			}
+		if (dst->count == 0)
+			return;
+	}
+
+	/* gr16-gr31 */
+	if (dst->count > 0 && dst->pos < ELF_NAT_OFFSET) {
+		pt = task_pt_regs(dst->target);
+		dst->ret = user_regset_copyin(&dst->pos, &dst->count,
+				&dst->u.set.kbuf, &dst->u.set.ubuf, &pt->r16,
+				ELF_GR_OFFSET(16), ELF_NAT_OFFSET);
+		if (dst->ret || dst->count == 0)
+			return;
+	}
+
+	/* nat, pr, b0 - b7 */
+	if (dst->count > 0 && dst->pos < ELF_CR_IIP_OFFSET) {
+		i = dst->pos;
+		index = (dst->pos - ELF_NAT_OFFSET) / sizeof(elf_greg_t);
+		dst->ret = user_regset_copyin(&dst->pos, &dst->count,
+				&dst->u.set.kbuf, &dst->u.set.ubuf, tmp,
+				ELF_NAT_OFFSET, ELF_CR_IIP_OFFSET);
+		if (dst->ret)
+			return;
+		for (; i < dst->pos; i += sizeof(elf_greg_t), index++)
+			if (access_elf_reg(dst->target, info, i,
+						&tmp[index], 1) < 0) {
+				dst->ret = -EIO;
+				return;
+			}
+		if (dst->count == 0)
+			return;
+	}
+
+	/* ip cfm psr ar.rsc ar.bsp ar.bspstore ar.rnat
+	 * ar.ccv ar.unat ar.fpsr ar.pfs ar.lc ar.ec ar.csd ar.ssd
+	 */
+	if (dst->count > 0 && dst->pos < (ELF_AR_END_OFFSET)) {
+		i = dst->pos;
+		index = (dst->pos - ELF_CR_IIP_OFFSET) / sizeof(elf_greg_t);
+		dst->ret = user_regset_copyin(&dst->pos, &dst->count,
+				&dst->u.set.kbuf, &dst->u.set.ubuf, tmp,
+				ELF_CR_IIP_OFFSET, ELF_AR_END_OFFSET);
+		if (dst->ret)
+			return;
+		for ( ; i < dst->pos; i += sizeof(elf_greg_t), index++)
+			if (access_elf_reg(dst->target, info, i,
+						&tmp[index], 1) < 0) {
+				dst->ret = -EIO;
+				return;
+			}
+	}
+}
+
+#define ELF_FP_OFFSET(i)	(i * sizeof(elf_fpreg_t))
+
+void do_fpregs_get(struct unw_frame_info *info, void *arg)
+{
+	struct regset_getset *dst = arg;
+	struct task_struct *task = dst->target;
+	elf_fpreg_t tmp[30];
+	int index, min_copy, i;
+
+	if (unw_unwind_to_user(info) < 0)
+		return;
+
+	/* Skip pos 0 and 1 */
+	if (dst->count > 0 && dst->pos < ELF_FP_OFFSET(2)) {
+		dst->ret = user_regset_copyout_zero(&dst->pos, &dst->count,
+						      &dst->u.get.kbuf,
+						      &dst->u.get.ubuf,
+						      0, ELF_FP_OFFSET(2));
+		if (dst->count == 0 || dst->ret)
+			return;
+	}
+
+	/* fr2-fr31 */
+	if (dst->count > 0 && dst->pos < ELF_FP_OFFSET(32)) {
+		index = (dst->pos - ELF_FP_OFFSET(2)) / sizeof(elf_fpreg_t);
+
+		min_copy = min(((unsigned int)ELF_FP_OFFSET(32)),
+				dst->pos + dst->count);
+		for (i = dst->pos; i < min_copy; i += sizeof(elf_fpreg_t),
+				index++)
+			if (unw_get_fr(info, i / sizeof(elf_fpreg_t),
+					 &tmp[index])) {
+				dst->ret = -EIO;
+				return;
+			}
+		dst->ret = user_regset_copyout(&dst->pos, &dst->count,
+				&dst->u.get.kbuf, &dst->u.get.ubuf, tmp,
+				ELF_FP_OFFSET(2), ELF_FP_OFFSET(32));
+		if (dst->count == 0 || dst->ret)
+			return;
+	}
+
+	/* fph */
+	if (dst->count > 0) {
+		ia64_flush_fph(dst->target);
+		if (task->thread.flags & IA64_THREAD_FPH_VALID)
+			dst->ret = user_regset_copyout(
+				&dst->pos, &dst->count,
+				&dst->u.get.kbuf, &dst->u.get.ubuf,
+				&dst->target->thread.fph,
+				ELF_FP_OFFSET(32), -1);
+		else
+			/* Zero fill instead.  */
+			dst->ret = user_regset_copyout_zero(
+				&dst->pos, &dst->count,
+				&dst->u.get.kbuf, &dst->u.get.ubuf,
+				ELF_FP_OFFSET(32), -1);
+	}
+}
+
+void do_fpregs_set(struct unw_frame_info *info, void *arg)
+{
+	struct regset_getset *dst = arg;
+	elf_fpreg_t fpreg, tmp[30];
+	int index, start, end;
+
+	if (unw_unwind_to_user(info) < 0)
+		return;
+
+	/* Skip pos 0 and 1 */
+	if (dst->count > 0 && dst->pos < ELF_FP_OFFSET(2)) {
+		dst->ret = user_regset_copyin_ignore(&dst->pos, &dst->count,
+						       &dst->u.set.kbuf,
+						       &dst->u.set.ubuf,
+						       0, ELF_FP_OFFSET(2));
+		if (dst->count == 0 || dst->ret)
+			return;
+	}
+
+	/* fr2-fr31 */
+	if (dst->count > 0 && dst->pos < ELF_FP_OFFSET(32)) {
+		start = dst->pos;
+		end = min(((unsigned int)ELF_FP_OFFSET(32)),
+			 dst->pos + dst->count);
+		dst->ret = user_regset_copyin(&dst->pos, &dst->count,
+				&dst->u.set.kbuf, &dst->u.set.ubuf, tmp,
+				ELF_FP_OFFSET(2), ELF_FP_OFFSET(32));
+		if (dst->ret)
+			return;
+
+		if (start & 0xF) { /* only write high part */
+			if (unw_get_fr(info, start / sizeof(elf_fpreg_t),
+					 &fpreg)) {
+				dst->ret = -EIO;
+				return;
+			}
+			tmp[start / sizeof(elf_fpreg_t) - 2].u.bits[0]
+				= fpreg.u.bits[0];
+			start &= ~0xFUL;
+		}
+		if (end & 0xF) { /* only write low part */
+			if (unw_get_fr(info, end / sizeof(elf_fpreg_t),
+					&fpreg)) {
+				dst->ret = -EIO;
+				return;
+			}
+			tmp[end / sizeof(elf_fpreg_t) - 2].u.bits[1]
+				= fpreg.u.bits[1];
+			end = (end + 0xF) & ~0xFUL;
+		}
+
+		for ( ;	start < end ; start += sizeof(elf_fpreg_t)) {
+			index = start / sizeof(elf_fpreg_t);
+			if (unw_set_fr(info, index, tmp[index - 2])) {
+				dst->ret = -EIO;
+				return;
+			}
+		}
+		if (dst->ret || dst->count == 0)
+			return;
+	}
+
+	/* fph */
+	if (dst->count > 0 && dst->pos < ELF_FP_OFFSET(128)) {
+		ia64_sync_fph(dst->target);
+		dst->ret = user_regset_copyin(&dst->pos, &dst->count,
+						&dst->u.set.kbuf,
+						&dst->u.set.ubuf,
+						&dst->target->thread.fph,
+						ELF_FP_OFFSET(32), -1);
+	}
+}
+
+static int
+do_regset_call(void (*call)(struct unw_frame_info *, void *),
+	       struct task_struct *target,
+	       const struct user_regset *regset,
+	       unsigned int pos, unsigned int count,
+	       const void *kbuf, const void __user *ubuf)
+{
+	struct regset_getset info = { .target = target, .regset = regset,
+				 .pos = pos, .count = count,
+				 .u.set = { .kbuf = kbuf, .ubuf = ubuf },
+				 .ret = 0 };
+
+	if (target == current)
+		unw_init_running(call, &info);
+	else {
+		struct unw_frame_info ufi;
+		memset(&ufi, 0, sizeof(ufi));
+		unw_init_from_blocked_task(&ufi, target);
+		(*call)(&ufi, &info);
+	}
+
+	return info.ret;
+}
+
+static int
+gpregs_get(struct task_struct *target,
+	   const struct user_regset *regset,
+	   unsigned int pos, unsigned int count,
+	   void *kbuf, void __user *ubuf)
+{
+	return do_regset_call(do_gpregs_get, target, regset, pos, count,
+		kbuf, ubuf);
+}
+
+static int gpregs_set(struct task_struct *target,
+		const struct user_regset *regset,
+		unsigned int pos, unsigned int count,
+		const void *kbuf, const void __user *ubuf)
+{
+	return do_regset_call(do_gpregs_set, target, regset, pos, count,
+		kbuf, ubuf);
+}
+
+static void do_gpregs_writeback(struct unw_frame_info *info, void *arg)
+{
+	do_sync_rbs(info, ia64_sync_user_rbs);
+}
+
+/*
+ * This is called to write back the register backing store.
+ * ptrace does this before it stops, so that a tracer reading the user
+ * memory after the thread stops will get the current register data.
+ */
+static int
+gpregs_writeback(struct task_struct *target,
+		 const struct user_regset *regset,
+		 int now)
+{
+	if (test_and_set_tsk_thread_flag(target, TIF_RESTORE_RSE))
+		return 0;
+	tsk_set_notify_resume(target);
+	return do_regset_call(do_gpregs_writeback, target, regset, 0, 0,
+		NULL, NULL);
+}
+
+static int
+fpregs_active(struct task_struct *target, const struct user_regset *regset)
+{
+	return (target->thread.flags & IA64_THREAD_FPH_VALID) ? 128 : 32;
+}
+
+static int fpregs_get(struct task_struct *target,
+		const struct user_regset *regset,
+		unsigned int pos, unsigned int count,
+		void *kbuf, void __user *ubuf)
+{
+	return do_regset_call(do_fpregs_get, target, regset, pos, count,
+		kbuf, ubuf);
+}
+
+static int fpregs_set(struct task_struct *target,
+		const struct user_regset *regset,
+		unsigned int pos, unsigned int count,
+		const void *kbuf, const void __user *ubuf)
+{
+	return do_regset_call(do_fpregs_set, target, regset, pos, count,
+		kbuf, ubuf);
+}
+
+static const struct user_regset native_regsets[] = {
+	{
+		.core_note_type = NT_PRSTATUS,
+		.n = ELF_NGREG,
+		.size = sizeof(elf_greg_t), .align = sizeof(elf_greg_t),
+		.get = gpregs_get, .set = gpregs_set,
+		.writeback = gpregs_writeback
+	},
+	{
+		.core_note_type = NT_PRFPREG,
+		.n = ELF_NFPREG,
+		.size = sizeof(elf_fpreg_t), .align = sizeof(elf_fpreg_t),
+		.get = fpregs_get, .set = fpregs_set, .active = fpregs_active
+	},
+};
+
+static const struct user_regset_view user_ia64_view = {
+	.name = "ia64",
+	.e_machine = EM_IA_64,
+	.regsets = native_regsets, .n = ARRAY_SIZE(native_regsets)
+};
+
+const struct user_regset_view *task_user_regset_view(struct task_struct *tsk)
+{
+	return &user_ia64_view;
+}

include/asm-ia64/elf.h

@@ -154,6 +154,30 @@ extern void ia64_init_addr_space (void);
 #define ELF_NGREG	128	/* we really need just 72 but let's leave some headroom... */
 #define ELF_NFPREG	128	/* f0 and f1 could be omitted, but so what... */
 
+/* elf_gregset_t register offsets */
+#define ELF_GR_0_OFFSET     0
+#define ELF_NAT_OFFSET     (32 * sizeof(elf_greg_t))
+#define ELF_PR_OFFSET      (33 * sizeof(elf_greg_t))
+#define ELF_BR_0_OFFSET    (34 * sizeof(elf_greg_t))
+#define ELF_CR_IIP_OFFSET  (42 * sizeof(elf_greg_t))
+#define ELF_CFM_OFFSET     (43 * sizeof(elf_greg_t))
+#define ELF_CR_IPSR_OFFSET (44 * sizeof(elf_greg_t))
+#define ELF_GR_OFFSET(i)   (ELF_GR_0_OFFSET + i * sizeof(elf_greg_t))
+#define ELF_BR_OFFSET(i)   (ELF_BR_0_OFFSET + i * sizeof(elf_greg_t))
+#define ELF_AR_RSC_OFFSET  (45 * sizeof(elf_greg_t))
+#define ELF_AR_BSP_OFFSET  (46 * sizeof(elf_greg_t))
+#define ELF_AR_BSPSTORE_OFFSET (47 * sizeof(elf_greg_t))
+#define ELF_AR_RNAT_OFFSET (48 * sizeof(elf_greg_t))
+#define ELF_AR_CCV_OFFSET  (49 * sizeof(elf_greg_t))
+#define ELF_AR_UNAT_OFFSET (50 * sizeof(elf_greg_t))
+#define ELF_AR_FPSR_OFFSET (51 * sizeof(elf_greg_t))
+#define ELF_AR_PFS_OFFSET  (52 * sizeof(elf_greg_t))
+#define ELF_AR_LC_OFFSET   (53 * sizeof(elf_greg_t))
+#define ELF_AR_EC_OFFSET   (54 * sizeof(elf_greg_t))
+#define ELF_AR_CSD_OFFSET  (55 * sizeof(elf_greg_t))
+#define ELF_AR_SSD_OFFSET  (56 * sizeof(elf_greg_t))
+#define ELF_AR_END_OFFSET  (57 * sizeof(elf_greg_t))
+
 typedef unsigned long elf_fpxregset_t;
 
 typedef unsigned long elf_greg_t;