libunwind/src/ptrace/_UPT_access_reg.c - nest-cam/4320010/libunwind - Git at Google

 /* libunwind - a platform-independent unwind library
    Copyright (C) 2003-2005 Hewlett-Packard Co
 	Contributed by David Mosberger-Tang <davidm@hpl.hp.com>
    Copyright (C) 2010 Konstantin Belousov <kib@freebsd.org>

 This file is part of libunwind.

 Permission is hereby granted, free of charge, to any person obtaining
 a copy of this software and associated documentation files (the
 "Software"), to deal in the Software without restriction, including
 without limitation the rights to use, copy, modify, merge, publish,
 distribute, sublicense, and/or sell copies of the Software, and to
 permit persons to whom the Software is furnished to do so, subject to
 the following conditions:

 The above copyright notice and this permission notice shall be
 included in all copies or substantial portions of the Software.

 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.  */

 #include "_UPT_internal.h"

 #if UNW_TARGET_IA64
 # include <elf.h>
 # ifdef HAVE_ASM_PTRACE_OFFSETS_H
 #   include <asm/ptrace_offsets.h>
 # endif
 # include "tdep-ia64/rse.h"
 #elif defined(__aarch64__)
 # include <sys/uio.h>
 #endif

 #if HAVE_DECL_PTRACE_POKEUSER || HAVE_TTRACE
 int
 _UPT_access_reg (unw_addr_space_t as, unw_regnum_t reg, unw_word_t *val,
 		 int write, void *arg)
 {
   struct UPT_info *ui = arg;
   pid_t pid = ui->pid;

 #if UNW_DEBUG
   Debug(16, "using pokeuser: reg: %s [%u], val: %lx, write: %d\n", unw_regname(reg), (unsigned) reg, (long) val, write);

   if (write)
     Debug (16, "%s <- %lx\n", unw_regname (reg), (long) *val);
 #endif

 #if UNW_TARGET_IA64
   if ((unsigned) reg - UNW_IA64_NAT < 32)
     {
       unsigned long nat_bits, mask;

       /* The Linux ptrace represents the statc NaT bits as a single word.  */
       mask = ((unw_word_t) 1) << (reg - UNW_IA64_NAT);
       errno = 0;
 #ifdef HAVE_TTRACE
 #	warning No support for ttrace() yet.
 #else
       nat_bits = ptrace (PTRACE_PEEKUSER, pid, PT_NAT_BITS, 0);
       if (errno)
 	goto badreg;
 #endif

       if (write)
 	{
 	  if (*val)
 	    nat_bits |= mask;
 	  else
 	    nat_bits &= ~mask;
 #ifdef HAVE_TTRACE
 #	warning No support for ttrace() yet.
 #else
 	  errno = 0;
 	  ptrace (PTRACE_POKEUSER, pid, PT_NAT_BITS, nat_bits);
 	  if (errno)
 	    goto badreg;
 #endif
 	}
       goto out;
     }
   else
     switch (reg)
       {
       case UNW_IA64_GR + 0:
 	if (write)
 	  goto badreg;
 	*val = 0;
 	return 0;

       case UNW_REG_IP:
 	{
 	  unsigned long ip, psr;

 	  /* distribute bundle-addr. & slot-number across PT_IIP & PT_IPSR.  */
 #ifdef HAVE_TTRACE
 #	warning No support for ttrace() yet.
 #else
 	  errno = 0;
 	  psr = ptrace (PTRACE_PEEKUSER, pid, PT_CR_IPSR, 0);
 	  if (errno)
 	    goto badreg;
 #endif
 	  if (write)
 	    {
 	      ip = *val & ~0xfUL;
 	      psr = (psr & ~0x3UL << 41) | (*val & 0x3);
 #ifdef HAVE_TTRACE
 #	warning No support for ttrace() yet.
 #else
 	      errno = 0;
 	      ptrace (PTRACE_POKEUSER, pid, PT_CR_IIP, ip);
 	      ptrace (PTRACE_POKEUSER, pid, PT_CR_IPSR, psr);
 	      if (errno)
 		goto badreg;
 #endif
 	    }
 	  else
 	    {
 #ifdef HAVE_TTRACE
 #	warning No support for ttrace() yet.
 #else
 	      errno = 0;
 	      ip = ptrace (PTRACE_PEEKUSER, pid, PT_CR_IIP, 0);
 	      if (errno)
 		goto badreg;
 #endif
 	      *val = ip + ((psr >> 41) & 0x3);
 	    }
 	  goto out;
 	}

       case UNW_IA64_AR_BSPSTORE:
 	reg = UNW_IA64_AR_BSP;
 	break;

       case UNW_IA64_AR_BSP:
       case UNW_IA64_BSP:
 	{
 	  unsigned long sof, cfm, bsp;

 #ifdef HAVE_TTRACE
 #	warning No support for ttrace() yet.
 #else
 	  /* Account for the fact that ptrace() expects bsp to point
 	     _after_ the current register frame.  */
 	  errno = 0;
 	  cfm = ptrace (PTRACE_PEEKUSER, pid, PT_CFM, 0);
 	  if (errno)
 	    goto badreg;
 #endif
 	  sof = (cfm & 0x7f);

 	  if (write)
 	    {
 	      bsp = rse_skip_regs (*val, sof);
 #ifdef HAVE_TTRACE
 #	warning No support for ttrace() yet.
 #else
 	      errno = 0;
 	      ptrace (PTRACE_POKEUSER, pid, PT_AR_BSP, bsp);
 	      if (errno)
 		goto badreg;
 #endif
 	    }
 	  else
 	    {
 #ifdef HAVE_TTRACE
 #	warning No support for ttrace() yet.
 #else
 	      errno = 0;
 	      bsp = ptrace (PTRACE_PEEKUSER, pid, PT_AR_BSP, 0);
 	      if (errno)
 		goto badreg;
 #endif
 	      *val = rse_skip_regs (bsp, -sof);
 	    }
 	  goto out;
 	}

       case UNW_IA64_CFM:
 	/* If we change CFM, we need to adjust ptrace's notion of bsp
 	   accordingly, so that the real bsp remains unchanged.  */
 	if (write)
 	  {
 	    unsigned long new_sof, old_sof, cfm, bsp;

 #ifdef HAVE_TTRACE
 #	warning No support for ttrace() yet.
 #else
 	    errno = 0;
 	    bsp = ptrace (PTRACE_PEEKUSER, pid, PT_AR_BSP, 0);
 	    cfm = ptrace (PTRACE_PEEKUSER, pid, PT_CFM, 0);
 #endif
 	    if (errno)
 	      goto badreg;
 	    old_sof = (cfm & 0x7f);
 	    new_sof = (*val & 0x7f);
 	    if (old_sof != new_sof)
 	      {
 		bsp = rse_skip_regs (bsp, -old_sof + new_sof);
 #ifdef HAVE_TTRACE
 #	warning No support for ttrace() yet.
 #else
 		errno = 0;
 		ptrace (PTRACE_POKEUSER, pid, PT_AR_BSP, 0);
 		if (errno)
 		  goto badreg;
 #endif
 	      }
 #ifdef HAVE_TTRACE
 #	warning No support for ttrace() yet.
 #else
 	    errno = 0;
 	    ptrace (PTRACE_POKEUSER, pid, PT_CFM, *val);
 	    if (errno)
 	      goto badreg;
 #endif
 	    goto out;
 	  }
 	break;
       }
 #endif /* End of IA64 */

   if ((unsigned) reg >= ARRAY_SIZE (_UPT_reg_offset))
     {
 #if UNW_DEBUG
       Debug(2, "register out of range: >= %zu / %zu\n", sizeof(_UPT_reg_offset), sizeof(_UPT_reg_offset[0]));
 #endif
       errno = EINVAL;
       goto badreg;
     }

 #ifdef HAVE_TTRACE
 #	warning No support for ttrace() yet.
 #else
   errno = 0;
   if (write)
     /* ANDROID support update. */
     ptrace (PTRACE_POKEUSER, pid, (void*) (uintptr_t) _UPT_reg_offset[reg], (void*) *val);
     /* End of ANDROID update. */
   else {
 #if UNW_DEBUG
     Debug(16, "ptrace PEEKUSER pid: %lu , reg: %lu , offs: %lu\n", (unsigned long)pid, (unsigned long)reg,
         (unsigned long)_UPT_reg_offset[reg]);
 #endif
     /* ANDROID support update. */
     *val = ptrace (PTRACE_PEEKUSER, pid, (void*) (uintptr_t) _UPT_reg_offset[reg], 0);
     /* End of ANDROID update. */
   }
   if (errno) {
 #if UNW_DEBUG
     Debug(2, "ptrace failure\n");
 #endif
     goto badreg;
   }
 #endif

 #ifdef UNW_TARGET_IA64
  out:
 #endif
 #if UNW_DEBUG
   if (!write)
     Debug (16, "%s[%u] -> %lx\n", unw_regname (reg), (unsigned) reg, (long) *val);
 #endif
   return 0;

  badreg:
   Debug (1, "bad register %s [%u] (error: %s)\n", unw_regname(reg), reg, strerror (errno));
   return -UNW_EBADREG;
 }
 #elif HAVE_DECL_PT_GETREGS
 int
 _UPT_access_reg (unw_addr_space_t as, unw_regnum_t reg, unw_word_t *val,
 		 int write, void *arg)
 {
   struct UPT_info *ui = arg;
   pid_t pid = ui->pid;
 /* ANDROID support update. */
 #if defined(__mips__)
   struct
     {
       uint64_t regs[32];
       uint64_t lo;
       uint64_t hi;
       uint64_t epc;
       uint64_t badvaddr;
       uint64_t status;
       uint64_t cause;
     }
   regs;
 #else
   char *r;
   gregset_t regs;
 #endif

 #if UNW_DEBUG
   Debug(16, "using getregs: reg: %s [%u], val: %lx, write: %u\n", unw_regname(reg), (unsigned) reg, (long) val, write);

   if (write)
     Debug (16, "%s [%u] <- %lx\n", unw_regname (reg), (unsigned) reg, (long) *val);
 #endif
 #if defined(__mips__)
   if (ptrace(PTRACE_GETREGS, pid, 0, (void*)&regs) == -1)
     goto badreg;
   if (write)
     {
       if (reg <= UNW_MIPS_R31)
         regs.regs[reg] = *val;
       else if (reg == UNW_MIPS_PC)
         regs.epc = *val;
       else
         goto badreg;
       if (ptrace(PTRACE_SETREGS, pid, 0, (void*)&regs) == -1)
         goto badreg;
     }
   else
     {
       if (reg <= UNW_MIPS_R31)
         *val = regs.regs[reg];
       else if (reg == UNW_MIPS_PC)
         *val = regs.epc;
       else
         goto badreg;
     }
 #else
   if ((unsigned) reg >= ARRAY_SIZE (_UPT_reg_offset))
     {
       errno = EINVAL;
       goto badreg;
     }
   r = (char *)&regs + _UPT_reg_offset[reg];
   if (ptrace(PT_GETREGS, pid, (caddr_t)&regs, 0) == -1)
     goto badreg;
   if (write) {
       memcpy(r, val, sizeof(unw_word_t));
       if (ptrace(PT_SETREGS, pid, (caddr_t)&regs, 0) == -1)
         goto badreg;
   } else
       memcpy(val, r, sizeof(unw_word_t));
 #endif
 /* End of ANDROID update. */
   return 0;

  badreg:
   Debug (1, "bad register %s [%u] (error: %s)\n", unw_regname(reg), reg, strerror (errno));
   return -UNW_EBADREG;
 }
 /* ANDROID support update. */
 #elif HAVE_DECL_PT_GETREGSET
 int
 _UPT_access_reg (unw_addr_space_t as, unw_regnum_t reg, unw_word_t *val,
 		 int write, void *arg)
 {
   struct UPT_info *ui = arg;
   pid_t pid = ui->pid;
 #if defined(__aarch64__)
   struct user_pt_regs regs;
   struct iovec io;
   io.iov_base = &regs;
   io.iov_len = sizeof(regs);

 #if UNW_DEBUG
   Debug(16, "using getregset: reg: %s [%u], val: %lx, write: %u\n", unw_regname(reg), (unsigned) reg, (long) val, write);

   if (write)
     Debug (16, "%s [%u] <- %lx\n", unw_regname (reg), (unsigned) reg, (long) *val);
 #endif
   if (ptrace(PTRACE_GETREGSET, pid, (void*)NT_PRSTATUS, (void*)&io) == -1)
     goto badreg;
   if (write)
     {
       if (reg == UNW_AARCH64_SP)
         regs.sp = *val;
       else if (reg == UNW_AARCH64_PC)
         regs.pc = *val;
       else if (reg < UNW_AARCH64_SP)
         regs.regs[reg] = *val;
       else
         goto badreg;
       if (ptrace(PTRACE_SETREGSET, pid, (void*)NT_PRSTATUS, (void*)&io) == -1)
         goto badreg;
     }
   else
     {
       if (reg == UNW_AARCH64_SP)
         *val = regs.sp;
       else if (reg == UNW_AARCH64_PC)
         *val = regs.pc;
       else if (reg < UNW_AARCH64_SP)
         *val = regs.regs[reg];
       else
         goto badreg;
     }
 #else
 #error Unsupported architecture for getregset
 #endif
   return 0;

  badreg:
   Debug (1, "bad register %s [%u] (error: %s)\n", unw_regname(reg), reg, strerror (errno));
   return -UNW_EBADREG;
 }
 /* End of ANDROID update. */
 #else
 #error Port me
 #endif
	/* libunwind - a platform-independent unwind library
	Copyright (C) 2003-2005 Hewlett-Packard Co
	Contributed by David Mosberger-Tang <davidm@hpl.hp.com>
	Copyright (C) 2010 Konstantin Belousov <kib@freebsd.org>

	This file is part of libunwind.

	Permission is hereby granted, free of charge, to any person obtaining
	a copy of this software and associated documentation files (the
	"Software"), to deal in the Software without restriction, including
	without limitation the rights to use, copy, modify, merge, publish,
	distribute, sublicense, and/or sell copies of the Software, and to
	permit persons to whom the Software is furnished to do so, subject to
	the following conditions:

	The above copyright notice and this permission notice shall be
	included in all copies or substantial portions of the Software.

	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
	EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
	MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
	NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
	LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
	OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
	WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */

	#include "_UPT_internal.h"

	#if UNW_TARGET_IA64
	# include <elf.h>
	# ifdef HAVE_ASM_PTRACE_OFFSETS_H
	# include <asm/ptrace_offsets.h>
	# endif
	# include "tdep-ia64/rse.h"
	#elif defined(__aarch64__)
	# include <sys/uio.h>
	#endif

	#if HAVE_DECL_PTRACE_POKEUSER \|\| HAVE_TTRACE
	int
	_UPT_access_reg (unw_addr_space_t as, unw_regnum_t reg, unw_word_t *val,
	int write, void *arg)
	{
	struct UPT_info *ui = arg;
	pid_t pid = ui->pid;

	#if UNW_DEBUG
	Debug(16, "using pokeuser: reg: %s [%u], val: %lx, write: %d\n", unw_regname(reg), (unsigned) reg, (long) val, write);

	if (write)
	Debug (16, "%s <- %lx\n", unw_regname (reg), (long) *val);
	#endif

	#if UNW_TARGET_IA64
	if ((unsigned) reg - UNW_IA64_NAT < 32)
	{
	unsigned long nat_bits, mask;

	/* The Linux ptrace represents the statc NaT bits as a single word. */
	mask = ((unw_word_t) 1) << (reg - UNW_IA64_NAT);
	errno = 0;
	#ifdef HAVE_TTRACE
	# warning No support for ttrace() yet.
	#else
	nat_bits = ptrace (PTRACE_PEEKUSER, pid, PT_NAT_BITS, 0);
	if (errno)
	goto badreg;
	#endif

	if (write)
	{
	if (*val)
	nat_bits \|= mask;
	else
	nat_bits &= ~mask;
	#ifdef HAVE_TTRACE
	# warning No support for ttrace() yet.
	#else
	errno = 0;
	ptrace (PTRACE_POKEUSER, pid, PT_NAT_BITS, nat_bits);
	if (errno)
	goto badreg;
	#endif
	}
	goto out;
	}
	else
	switch (reg)
	{
	case UNW_IA64_GR + 0:
	if (write)
	goto badreg;
	*val = 0;
	return 0;

	case UNW_REG_IP:
	{
	unsigned long ip, psr;

	/* distribute bundle-addr. & slot-number across PT_IIP & PT_IPSR. */
	#ifdef HAVE_TTRACE
	# warning No support for ttrace() yet.
	#else
	errno = 0;
	psr = ptrace (PTRACE_PEEKUSER, pid, PT_CR_IPSR, 0);
	if (errno)
	goto badreg;
	#endif
	if (write)
	{
	ip = *val & ~0xfUL;
	psr = (psr & ~0x3UL << 41) \| (*val & 0x3);
	#ifdef HAVE_TTRACE
	# warning No support for ttrace() yet.
	#else
	errno = 0;
	ptrace (PTRACE_POKEUSER, pid, PT_CR_IIP, ip);
	ptrace (PTRACE_POKEUSER, pid, PT_CR_IPSR, psr);
	if (errno)
	goto badreg;
	#endif
	}
	else
	{
	#ifdef HAVE_TTRACE
	# warning No support for ttrace() yet.
	#else
	errno = 0;
	ip = ptrace (PTRACE_PEEKUSER, pid, PT_CR_IIP, 0);
	if (errno)
	goto badreg;
	#endif
	*val = ip + ((psr >> 41) & 0x3);
	}
	goto out;
	}

	case UNW_IA64_AR_BSPSTORE:
	reg = UNW_IA64_AR_BSP;
	break;

	case UNW_IA64_AR_BSP:
	case UNW_IA64_BSP:
	{
	unsigned long sof, cfm, bsp;

	#ifdef HAVE_TTRACE
	# warning No support for ttrace() yet.
	#else
	/* Account for the fact that ptrace() expects bsp to point
	_after_ the current register frame. */
	errno = 0;
	cfm = ptrace (PTRACE_PEEKUSER, pid, PT_CFM, 0);
	if (errno)
	goto badreg;
	#endif
	sof = (cfm & 0x7f);

	if (write)
	{
	bsp = rse_skip_regs (*val, sof);
	#ifdef HAVE_TTRACE
	# warning No support for ttrace() yet.
	#else
	errno = 0;
	ptrace (PTRACE_POKEUSER, pid, PT_AR_BSP, bsp);
	if (errno)
	goto badreg;
	#endif
	}
	else
	{
	#ifdef HAVE_TTRACE
	# warning No support for ttrace() yet.
	#else
	errno = 0;
	bsp = ptrace (PTRACE_PEEKUSER, pid, PT_AR_BSP, 0);
	if (errno)
	goto badreg;
	#endif
	*val = rse_skip_regs (bsp, -sof);
	}
	goto out;
	}

	case UNW_IA64_CFM:
	/* If we change CFM, we need to adjust ptrace's notion of bsp
	accordingly, so that the real bsp remains unchanged. */
	if (write)
	{
	unsigned long new_sof, old_sof, cfm, bsp;

	#ifdef HAVE_TTRACE
	# warning No support for ttrace() yet.
	#else
	errno = 0;
	bsp = ptrace (PTRACE_PEEKUSER, pid, PT_AR_BSP, 0);
	cfm = ptrace (PTRACE_PEEKUSER, pid, PT_CFM, 0);
	#endif
	if (errno)
	goto badreg;
	old_sof = (cfm & 0x7f);
	new_sof = (*val & 0x7f);
	if (old_sof != new_sof)
	{
	bsp = rse_skip_regs (bsp, -old_sof + new_sof);
	#ifdef HAVE_TTRACE
	# warning No support for ttrace() yet.
	#else
	errno = 0;
	ptrace (PTRACE_POKEUSER, pid, PT_AR_BSP, 0);
	if (errno)
	goto badreg;
	#endif
	}
	#ifdef HAVE_TTRACE
	# warning No support for ttrace() yet.
	#else
	errno = 0;
	ptrace (PTRACE_POKEUSER, pid, PT_CFM, *val);
	if (errno)
	goto badreg;
	#endif
	goto out;
	}
	break;
	}
	#endif /* End of IA64 */

	if ((unsigned) reg >= ARRAY_SIZE (_UPT_reg_offset))
	{
	#if UNW_DEBUG
	Debug(2, "register out of range: >= %zu / %zu\n", sizeof(_UPT_reg_offset), sizeof(_UPT_reg_offset[0]));
	#endif
	errno = EINVAL;
	goto badreg;
	}

	#ifdef HAVE_TTRACE
	# warning No support for ttrace() yet.
	#else
	errno = 0;
	if (write)
	/* ANDROID support update. */
	ptrace (PTRACE_POKEUSER, pid, (void) (uintptr_t) _UPT_reg_offset[reg], (void) *val);
	/* End of ANDROID update. */
	else {
	#if UNW_DEBUG
	Debug(16, "ptrace PEEKUSER pid: %lu , reg: %lu , offs: %lu\n", (unsigned long)pid, (unsigned long)reg,
	(unsigned long)_UPT_reg_offset[reg]);
	#endif
	/* ANDROID support update. */
	val = ptrace (PTRACE_PEEKUSER, pid, (void) (uintptr_t) _UPT_reg_offset[reg], 0);
	/* End of ANDROID update. */
	}
	if (errno) {
	#if UNW_DEBUG
	Debug(2, "ptrace failure\n");
	#endif
	goto badreg;
	}
	#endif

	#ifdef UNW_TARGET_IA64
	out:
	#endif
	#if UNW_DEBUG
	if (!write)
	Debug (16, "%s[%u] -> %lx\n", unw_regname (reg), (unsigned) reg, (long) *val);
	#endif
	return 0;

	badreg:
	Debug (1, "bad register %s [%u] (error: %s)\n", unw_regname(reg), reg, strerror (errno));
	return -UNW_EBADREG;
	}
	#elif HAVE_DECL_PT_GETREGS
	int
	_UPT_access_reg (unw_addr_space_t as, unw_regnum_t reg, unw_word_t *val,
	int write, void *arg)
	{
	struct UPT_info *ui = arg;
	pid_t pid = ui->pid;
	/* ANDROID support update. */
	#if defined(__mips__)
	struct
	{
	uint64_t regs[32];
	uint64_t lo;
	uint64_t hi;
	uint64_t epc;
	uint64_t badvaddr;
	uint64_t status;
	uint64_t cause;
	}
	regs;
	#else
	char *r;
	gregset_t regs;
	#endif

	#if UNW_DEBUG
	Debug(16, "using getregs: reg: %s [%u], val: %lx, write: %u\n", unw_regname(reg), (unsigned) reg, (long) val, write);

	if (write)
	Debug (16, "%s [%u] <- %lx\n", unw_regname (reg), (unsigned) reg, (long) *val);
	#endif
	#if defined(__mips__)
	if (ptrace(PTRACE_GETREGS, pid, 0, (void*)&regs) == -1)
	goto badreg;
	if (write)
	{
	if (reg <= UNW_MIPS_R31)
	regs.regs[reg] = *val;
	else if (reg == UNW_MIPS_PC)
	regs.epc = *val;
	else
	goto badreg;
	if (ptrace(PTRACE_SETREGS, pid, 0, (void*)&regs) == -1)
	goto badreg;
	}
	else
	{
	if (reg <= UNW_MIPS_R31)
	*val = regs.regs[reg];
	else if (reg == UNW_MIPS_PC)
	*val = regs.epc;
	else
	goto badreg;
	}
	#else
	if ((unsigned) reg >= ARRAY_SIZE (_UPT_reg_offset))
	{
	errno = EINVAL;
	goto badreg;
	}
	r = (char *)&regs + _UPT_reg_offset[reg];
	if (ptrace(PT_GETREGS, pid, (caddr_t)&regs, 0) == -1)
	goto badreg;
	if (write) {
	memcpy(r, val, sizeof(unw_word_t));
	if (ptrace(PT_SETREGS, pid, (caddr_t)&regs, 0) == -1)
	goto badreg;
	} else
	memcpy(val, r, sizeof(unw_word_t));
	#endif
	/* End of ANDROID update. */
	return 0;

	badreg:
	Debug (1, "bad register %s [%u] (error: %s)\n", unw_regname(reg), reg, strerror (errno));
	return -UNW_EBADREG;
	}
	/* ANDROID support update. */
	#elif HAVE_DECL_PT_GETREGSET
	int
	_UPT_access_reg (unw_addr_space_t as, unw_regnum_t reg, unw_word_t *val,
	int write, void *arg)
	{
	struct UPT_info *ui = arg;
	pid_t pid = ui->pid;
	#if defined(__aarch64__)
	struct user_pt_regs regs;
	struct iovec io;
	io.iov_base = &regs;
	io.iov_len = sizeof(regs);

	#if UNW_DEBUG
	Debug(16, "using getregset: reg: %s [%u], val: %lx, write: %u\n", unw_regname(reg), (unsigned) reg, (long) val, write);

	if (write)
	Debug (16, "%s [%u] <- %lx\n", unw_regname (reg), (unsigned) reg, (long) *val);
	#endif
	if (ptrace(PTRACE_GETREGSET, pid, (void)NT_PRSTATUS, (void)&io) == -1)
	goto badreg;
	if (write)
	{
	if (reg == UNW_AARCH64_SP)
	regs.sp = *val;
	else if (reg == UNW_AARCH64_PC)
	regs.pc = *val;
	else if (reg < UNW_AARCH64_SP)
	regs.regs[reg] = *val;
	else
	goto badreg;
	if (ptrace(PTRACE_SETREGSET, pid, (void)NT_PRSTATUS, (void)&io) == -1)
	goto badreg;
	}
	else
	{
	if (reg == UNW_AARCH64_SP)
	*val = regs.sp;
	else if (reg == UNW_AARCH64_PC)
	*val = regs.pc;
	else if (reg < UNW_AARCH64_SP)
	*val = regs.regs[reg];
	else
	goto badreg;
	}
	#else
	#error Unsupported architecture for getregset
	#endif
	return 0;

	badreg:
	Debug (1, "bad register %s [%u] (error: %s)\n", unw_regname(reg), reg, strerror (errno));
	return -UNW_EBADREG;
	}
	/* End of ANDROID update. */
	#else
	#error Port me
	#endif