text: /*
   * Copyright (c) 1991, 1992 Paul Kranenburg <pk@cs.few.eur.nl>
   * Copyright (c) 1993 Branko Lankester <branko@hacktic.nl>
   * Copyright (c) 1993, 1994, 1995, 1996 Rick Sladkey <jrs@world.std.com>
   * Copyright (c) 1996-1999 Wichert Akkerman <wichert@cistron.nl>
   * Copyright (c) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
   *                     Linux for s390 port by D.J. Barrow
   *                    <barrow_dj@mail.yahoo.com,djbarrow@de.ibm.com>
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   * 3. The name of the author may not be used to endorse or promote products
   *    derived from this software without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
   * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
   * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
   * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
   * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  #include "defs.h"
  #include <sys/user.h>
  #include <sys/param.h>
  #include <fcntl.h>
  #if HAVE_SYS_XATTR_H
  # include <sys/xattr.h>
  #endif
  #include <sys/uio.h>
  
  #if defined(IA64)
  # include <asm/ptrace_offsets.h>
  # include <asm/rse.h>
  #endif
  
  #ifdef HAVE_SYS_REG_H
  # include <sys/reg.h>
  #endif
  
  #ifdef HAVE_LINUX_PTRACE_H
  # undef PTRACE_SYSCALL
  # ifdef HAVE_STRUCT_IA64_FPREG
  #  define ia64_fpreg XXX_ia64_fpreg
  # endif
  # ifdef HAVE_STRUCT_PT_ALL_USER_REGS
  #  define pt_all_user_regs XXX_pt_all_user_regs
  # endif
  # ifdef HAVE_STRUCT_PTRACE_PEEKSIGINFO_ARGS
  #  define ptrace_peeksiginfo_args XXX_ptrace_peeksiginfo_args
  # endif
  # include <linux/ptrace.h>
  # undef ptrace_peeksiginfo_args
  # undef ia64_fpreg
  # undef pt_all_user_regs
  #endif
  
  int
  string_to_uint(const char *str)
  {
  	char *error;
  	long value;
  
  	if (!*str)
  		return -1;
  	errno = 0;
  	value = strtol(str, &error, 10);
  	if (errno || *error || value < 0 || (long)(int)value != value)
  		return -1;
  	return (int)value;
  }
  
  int
  tv_nz(const struct timeval *a)
  {
  	return a->tv_sec || a->tv_usec;
  }
  
  int
  tv_cmp(const struct timeval *a, const struct timeval *b)
  {
  	if (a->tv_sec < b->tv_sec
  	    || (a->tv_sec == b->tv_sec && a->tv_usec < b->tv_usec))
  		return -1;
  	if (a->tv_sec > b->tv_sec
  	    || (a->tv_sec == b->tv_sec && a->tv_usec > b->tv_usec))
  		return 1;
  	return 0;
  }
  
  double
  tv_float(const struct timeval *tv)
  {
  	return tv->tv_sec + tv->tv_usec/1000000.0;
  }
  
  void
  tv_add(struct timeval *tv, const struct timeval *a, const struct timeval *b)
  {
  	tv->tv_sec = a->tv_sec + b->tv_sec;
  	tv->tv_usec = a->tv_usec + b->tv_usec;
  	if (tv->tv_usec >= 1000000) {
  		tv->tv_sec++;
  		tv->tv_usec -= 1000000;
  	}
  }
  
  void
  tv_sub(struct timeval *tv, const struct timeval *a, const struct timeval *b)
  {
  	tv->tv_sec = a->tv_sec - b->tv_sec;
  	tv->tv_usec = a->tv_usec - b->tv_usec;
  	if (((long) tv->tv_usec) < 0) {
  		tv->tv_sec--;
  		tv->tv_usec += 1000000;
  	}
  }
  
  void
  tv_div(struct timeval *tv, const struct timeval *a, int n)
  {
  	tv->tv_usec = (a->tv_sec % n * 1000000 + a->tv_usec + n / 2) / n;
  	tv->tv_sec = a->tv_sec / n + tv->tv_usec / 1000000;
  	tv->tv_usec %= 1000000;
  }
  
  void
  tv_mul(struct timeval *tv, const struct timeval *a, int n)
  {
  	tv->tv_usec = a->tv_usec * n;
  	tv->tv_sec = a->tv_sec * n + tv->tv_usec / 1000000;
  	tv->tv_usec %= 1000000;
  }
  
  const char *
  xlookup(const struct xlat *xlat, const unsigned int val)
  {
  	for (; xlat->str != NULL; xlat++)
  		if (xlat->val == val)
  			return xlat->str;
  	return NULL;
  }
  
  static int
  xlat_bsearch_compare(const void *a, const void *b)
  {
  	const unsigned int val1 = (const unsigned long) a;
  	const unsigned int val2 = ((const struct xlat *) b)->val;
  	return (val1 > val2) ? 1 : (val1 < val2) ? -1 : 0;
  }
  
  const char *
  xlat_search(const struct xlat *xlat, const size_t nmemb, const unsigned int val)
  {
  	const struct xlat *e =
  		bsearch((const void*) (const unsigned long) val,
  			xlat, nmemb, sizeof(*xlat), xlat_bsearch_compare);
  
  	return e ? e->str : NULL;
  }
  
  #if !defined HAVE_STPCPY
  char *
  stpcpy(char *dst, const char *src)
  {
  	while ((*dst = *src++) != '\0')
  		dst++;
  	return dst;
  }
  #endif
  
  /* Find a next bit which is set.
   * Starts testing at cur_bit.
   * Returns -1 if no more bits are set.
   *
   * We never touch bytes we don't need to.
   * On big-endian, array is assumed to consist of
   * current_wordsize wide words: for example, is current_wordsize is 4,
   * the bytes are walked in 3,2,1,0, 7,6,5,4, 11,10,9,8 ... sequence.
   * On little-endian machines, word size is immaterial.
   */
  int
  next_set_bit(const void *bit_array, unsigned cur_bit, unsigned size_bits)
  {
  	const unsigned endian = 1;
  	int little_endian = *(char*)&endian;
  
  	const uint8_t *array = bit_array;
  	unsigned pos = cur_bit / 8;
  	unsigned pos_xor_mask = little_endian ? 0 : current_wordsize-1;
  
  	for (;;) {
  		uint8_t bitmask;
  		uint8_t cur_byte;
  
  		if (cur_bit >= size_bits)
  			return -1;
  		cur_byte = array[pos ^ pos_xor_mask];
  		if (cur_byte == 0) {
  			cur_bit = (cur_bit + 8) & (-8);
  			pos++;
  			continue;
  		}
  		bitmask = 1 << (cur_bit & 7);
  		for (;;) {
  			if (cur_byte & bitmask)
  				return cur_bit;
  			cur_bit++;
  			if (cur_bit >= size_bits)
  				return -1;
  			bitmask <<= 1;
  			/* This check *can't be* optimized out: */
  			if (bitmask == 0)
  				break;
  		}
  		pos++;
  	}
  }
  /*
   * Print entry in struct xlat table, if there.
   */
  void
  printxval(const struct xlat *xlat, const unsigned int val, const char *dflt)
  {
  	const char *str = xlookup(xlat, val);
  
  	if (str)
  		tprints(str);
  	else
  		tprintf("%#x /* %s */", val, dflt);
  }
  
  /*
   * Print 64bit argument at position arg_no and return the index of the next
   * argument.
   */
  int
  printllval(struct tcb *tcp, const char *format, int arg_no)
  {
  #if SIZEOF_LONG > 4 && SIZEOF_LONG == SIZEOF_LONG_LONG
  # if SUPPORTED_PERSONALITIES > 1
  	if (current_wordsize > 4) {
  # endif
  		tprintf(format, tcp->u_arg[arg_no]);
  		arg_no++;
  # if SUPPORTED_PERSONALITIES > 1
  	} else {
  #  if defined(AARCH64) || defined(POWERPC64)
  		/* Align arg_no to the next even number. */
  		arg_no = (arg_no + 1) & 0xe;
  #  endif
  		tprintf(format, LONG_LONG(tcp->u_arg[arg_no], tcp->u_arg[arg_no + 1]));
  		arg_no += 2;
  	}
  # endif /* SUPPORTED_PERSONALITIES */
  #elif SIZEOF_LONG > 4
  #  error Unsupported configuration: SIZEOF_LONG > 4 && SIZEOF_LONG_LONG > SIZEOF_LONG
  #elif defined LINUX_MIPSN32
  	tprintf(format, tcp->ext_arg[arg_no]);
  	arg_no++;
  #elif defined X32
  	if (current_personality == 0) {
  		tprintf(format, tcp->ext_arg[arg_no]);
  		arg_no++;
  	} else {
  		tprintf(format, LONG_LONG(tcp->u_arg[arg_no], tcp->u_arg[arg_no + 1]));
  		arg_no += 2;
  	}
  #else
  # if defined __ARM_EABI__ || \
       defined LINUX_MIPSO32 || \
       defined POWERPC || \
       defined XTENSA
  	/* Align arg_no to the next even number. */
  	arg_no = (arg_no + 1) & 0xe;
  # endif
  	tprintf(format, LONG_LONG(tcp->u_arg[arg_no], tcp->u_arg[arg_no + 1]));
  	arg_no += 2;
  #endif
  
  	return arg_no;
  }
  
  /*
   * Interpret `xlat' as an array of flags
   * print the entries whose bits are on in `flags'
   * return # of flags printed.
   */
  void
  addflags(const struct xlat *xlat, int flags)
  {
  	for (; xlat->str; xlat++) {
  		if (xlat->val && (flags & xlat->val) == xlat->val) {
  			tprintf("|%s", xlat->str);
  			flags &= ~xlat->val;
  		}
  	}
  	if (flags) {
  		tprintf("|%#x", flags);
  	}
  }
  
  /*
   * Interpret `xlat' as an array of flags.
   * Print to static string the entries whose bits are on in `flags'
   * Return static string.
   */
  const char *
  sprintflags(const char *prefix, const struct xlat *xlat, int flags)
  {
  	static char outstr[1024];
  	char *outptr;
  	int found = 0;
  
  	outptr = stpcpy(outstr, prefix);
  
  	for (; xlat->str; xlat++) {
  		if ((flags & xlat->val) == xlat->val) {
  			if (found)
  				*outptr++ = '|';
  			outptr = stpcpy(outptr, xlat->str);
  			found = 1;
  			flags &= ~xlat->val;
  			if (!flags)
  				break;
  		}
  	}
  	if (flags) {
  		if (found)
  			*outptr++ = '|';
  		outptr += sprintf(outptr, "%#x", flags);
  	}
  
  	return outstr;
  }
  
  int
  printflags(const struct xlat *xlat, int flags, const char *dflt)
  {
  	int n;
  	const char *sep;
  
  	if (flags == 0 && xlat->val == 0) {
  		tprints(xlat->str);
  		return 1;
  	}
  
  	sep = "";
  	for (n = 0; xlat->str; xlat++) {
  		if (xlat->val && (flags & xlat->val) == xlat->val) {
  			tprintf("%s%s", sep, xlat->str);
  			flags &= ~xlat->val;
  			sep = "|";
  			n++;
  		}
  	}
  
  	if (n) {
  		if (flags) {
  			tprintf("%s%#x", sep, flags);
  			n++;
  		}
  	} else {
  		if (flags) {
  			tprintf("%#x", flags);
  			if (dflt)
  				tprintf(" /* %s */", dflt);
  		} else {
  			if (dflt)
  				tprints("0");
  		}
  	}
  
  	return n;
  }
  
  void
  printnum(struct tcb *tcp, long addr, const char *fmt)
  {
  	long num;
  
  	if (!addr) {
  		tprints("NULL");
  		return;
  	}
  	if (umove(tcp, addr, &num) < 0) {
  		tprintf("%#lx", addr);
  		return;
  	}
  	tprints("[");
  	tprintf(fmt, num);
  	tprints("]");
  }
  
  void
  printnum_int(struct tcb *tcp, long addr, const char *fmt)
  {
  	int num;
  
  	if (!addr) {
  		tprints("NULL");
  		return;
  	}
  	if (umove(tcp, addr, &num) < 0) {
  		tprintf("%#lx", addr);
  		return;
  	}
  	tprints("[");
  	tprintf(fmt, num);
  	tprints("]");
  }
  
  const char *
  sprinttime(time_t t)
  {
  	struct tm *tmp;
  	static char buf[sizeof("yyyy/mm/dd-hh:mm:ss")];
  
  	if (t == 0) {
  		strcpy(buf, "0");
  		return buf;
  	}
  	tmp = localtime(&t);
  	if (tmp)
  		snprintf(buf, sizeof buf, "%02d/%02d/%02d-%02d:%02d:%02d",
  			tmp->tm_year + 1900, tmp->tm_mon + 1, tmp->tm_mday,
  			tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
  	else
  		snprintf(buf, sizeof buf, "%lu", (unsigned long) t);
  
  	return buf;
  }
  
  static char *
  getfdproto(struct tcb *tcp, int fd, char *buf, unsigned bufsize)
  {
  #if HAVE_SYS_XATTR_H
  	ssize_t r;
  	char path[sizeof("/proc/%u/fd/%u") + 2 * sizeof(int)*3];
  
  	if (fd < 0)
  		return NULL;
  
  	sprintf(path, "/proc/%u/fd/%u", tcp->pid, fd);
  	r = getxattr(path, "system.sockprotoname", buf, bufsize - 1);
  	if (r <= 0)
  		return NULL;
  	else {
  		/*
  		 * This is a protection for the case when the kernel
  		 * side does not append a null byte to the buffer.
  		 */
  		buf[r] = '\0';
  		return buf;
  	}
  #else
  	return NULL;
  #endif
  }
  
  void
  printfd(struct tcb *tcp, int fd)
  {
  	char path[PATH_MAX + 1];
  	if (show_fd_path && getfdpath(tcp, fd, path, sizeof(path)) >= 0) {
  		static const char socket_prefix[] = "socket:[";
  		const size_t socket_prefix_len = sizeof(socket_prefix) - 1;
  		size_t path_len;
  
  		if (show_fd_path > 1 &&
  		    strncmp(path, socket_prefix, socket_prefix_len) == 0 &&
  		    path[(path_len = strlen(path)) - 1] == ']') {
  			unsigned long inodenr;
  #define PROTO_NAME_LEN 32
  			char proto_buf[PROTO_NAME_LEN];
  			const char *proto =
  				getfdproto(tcp, fd, proto_buf, PROTO_NAME_LEN);
  			inodenr = strtoul(path + socket_prefix_len, NULL, 10);
  			tprintf("%d<", fd);
  			if (!print_sockaddr_by_inode(inodenr, proto)) {
  				if (proto)
  					tprintf("%s:[%lu]", proto, inodenr);
  				else
  					tprints(path);
  			}
  			tprints(">");
  		} else {
  			tprintf("%d<%s>", fd, path);
  		}
  	} else
  		tprintf("%d", fd);
  }
  
  /*
   * Quote string `instr' of length `size'
   * Write up to (3 + `size' * 4) bytes to `outstr' buffer.
   * If `len' is -1, treat `instr' as a NUL-terminated string
   * and quote at most (`size' - 1) bytes.
   *
   * Returns 0 if len == -1 and NUL was seen, 1 otherwise.
   * Note that if len >= 0, always returns 1.
   */
  int
  string_quote(const char *instr, char *outstr, long len, int size)
  {
  	const unsigned char *ustr = (const unsigned char *) instr;
  	char *s = outstr;
  	int usehex, c, i, eol;
  
  	eol = 0x100; /* this can never match a char */
  	if (len == -1) {
  		size--;
  		eol = '\0';
  	}
  
  	usehex = 0;
  	if (xflag > 1)
  		usehex = 1;
  	else if (xflag) {
  		/* Check for presence of symbol which require
  		   to hex-quote the whole string. */
  		for (i = 0; i < size; ++i) {
  			c = ustr[i];
  			/* Check for NUL-terminated string. */
  			if (c == eol)
  				break;
  
  			/* Force hex unless c is printable or whitespace */
  			if (c > 0x7e) {
  				usehex = 1;
  				break;
  			}
  			/* In ASCII isspace is only these chars: "\t\n\v\f\r".
  			 * They happen to have ASCII codes 9,10,11,12,13.
  			 */
  			if (c < ' ' && (unsigned)(c - 9) >= 5) {
  				usehex = 1;
  				break;
  			}
  		}
  	}
  
  	*s++ = '\"';
  
  	if (usehex) {
  		/* Hex-quote the whole string. */
  		for (i = 0; i < size; ++i) {
  			c = ustr[i];
  			/* Check for NUL-terminated string. */
  			if (c == eol)
  				goto asciz_ended;
  			*s++ = '\\';
  			*s++ = 'x';
  			*s++ = "0123456789abcdef"[c >> 4];
  			*s++ = "0123456789abcdef"[c & 0xf];
  		}
  	} else {
  		for (i = 0; i < size; ++i) {
  			c = ustr[i];
  			/* Check for NUL-terminated string. */
  			if (c == eol)
  				goto asciz_ended;
  			switch (c) {
  				case '\"': case '\\':
  					*s++ = '\\';
  					*s++ = c;
  					break;
  				case '\f':
  					*s++ = '\\';
  					*s++ = 'f';
  					break;
  				case '\n':
  					*s++ = '\\';
  					*s++ = 'n';
  					break;
  				case '\r':
  					*s++ = '\\';
  					*s++ = 'r';
  					break;
  				case '\t':
  					*s++ = '\\';
  					*s++ = 't';
  					break;
  				case '\v':
  					*s++ = '\\';
  					*s++ = 'v';
  					break;
  				default:
  					if (c >= ' ' && c <= 0x7e)
  						*s++ = c;
  					else {
  						/* Print \octal */
  						*s++ = '\\';
  						if (i + 1 < size
  						    && ustr[i + 1] >= '0'
  						    && ustr[i + 1] <= '9'
  						) {
  							/* Print \ooo */
  							*s++ = '0' + (c >> 6);
  							*s++ = '0' + ((c >> 3) & 0x7);
  						} else {
  							/* Print \[[o]o]o */
  							if ((c >> 3) != 0) {
  								if ((c >> 6) != 0)
  									*s++ = '0' + (c >> 6);
  								*s++ = '0' + ((c >> 3) & 0x7);
  							}
  						}
  						*s++ = '0' + (c & 0x7);
  					}
  					break;
  			}
  		}
  	}
  
  	*s++ = '\"';
  	*s = '\0';
  
  	/* Return zero if we printed entire ASCIZ string (didn't truncate it) */
  	if (len == -1 && ustr[i] == '\0') {
  		/* We didn't see NUL yet (otherwise we'd jump to 'asciz_ended')
  		 * but next char is NUL.
  		 */
  		return 0;
  	}
  
  	return 1;
  
   asciz_ended:
  	*s++ = '\"';
  	*s = '\0';
  	/* Return zero: we printed entire ASCIZ string (didn't truncate it) */
  	return 0;
  }
  
  /*
   * Print path string specified by address `addr' and length `n'.
   * If path length exceeds `n', append `...' to the output.
   */
  void
  printpathn(struct tcb *tcp, long addr, unsigned int n)
  {
  	char path[PATH_MAX + 1];
  	int nul_seen;
  
  	if (!addr) {
  		tprints("NULL");
  		return;
  	}
  
  	/* Cap path length to the path buffer size */
  	if (n > sizeof path - 1)
  		n = sizeof path - 1;
  
  	/* Fetch one byte more to find out whether path length > n. */
  	nul_seen = umovestr(tcp, addr, n + 1, path);
  	if (nul_seen < 0)
  		tprintf("%#lx", addr);
  	else {
  		char *outstr;
  
  		path[n] = '\0';
  		n++;
  		outstr = alloca(4 * n); /* 4*(n-1) + 3 for quotes and NUL */
  		string_quote(path, outstr, -1, n);
  		tprints(outstr);
  		if (!nul_seen)
  			tprints("...");
  	}
  }
  
  void
  printpath(struct tcb *tcp, long addr)
  {
  	/* Size must correspond to char path[] size in printpathn */
  	printpathn(tcp, addr, PATH_MAX);
  }
  
  /*
   * Print string specified by address `addr' and length `len'.
   * If `len' < 0, treat the string as a NUL-terminated string.
   * If string length exceeds `max_strlen', append `...' to the output.
   */
  void
  printstr(struct tcb *tcp, long addr, long len)
  {
  	static char *str = NULL;
  	static char *outstr;
  	unsigned int size;
  	int ellipsis;
  
  	if (!addr) {
  		tprints("NULL");
  		return;
  	}
  	/* Allocate static buffers if they are not allocated yet. */
  	if (!str) {
  		unsigned int outstr_size = 4 * max_strlen + /*for quotes and NUL:*/ 3;
  
  		if (outstr_size / 4 != max_strlen)
  			die_out_of_memory();
  		str = malloc(max_strlen + 1);
  		if (!str)
  			die_out_of_memory();
  		outstr = malloc(outstr_size);
  		if (!outstr)
  			die_out_of_memory();
  	}
  
  	if (len == -1) {
  		/*
  		 * Treat as a NUL-terminated string: fetch one byte more
  		 * because string_quote() quotes one byte less.
  		 */
  		size = max_strlen + 1;
  		if (umovestr(tcp, addr, size, str) < 0) {
  			tprintf("%#lx", addr);
  			return;
  		}
  	}
  	else {
  		size = max_strlen;
  		if (size > (unsigned long)len)
  			size = (unsigned long)len;
  		if (umoven(tcp, addr, size, str) < 0) {
  			tprintf("%#lx", addr);
  			return;
  		}
  	}
  
  	/* If string_quote didn't see NUL and (it was supposed to be ASCIZ str
  	 * or we were requested to print more than -s NUM chars)...
  	 */
  	ellipsis = (string_quote(str, outstr, len, size) &&
  			(len < 0 || (unsigned long) len > max_strlen));
  
  	tprints(outstr);
  	if (ellipsis)
  		tprints("...");
  }
  
  void
  dumpiov(struct tcb *tcp, int len, long addr)
  {
  #if SUPPORTED_PERSONALITIES > 1
  	union {
  		struct { u_int32_t base; u_int32_t len; } *iov32;
  		struct { u_int64_t base; u_int64_t len; } *iov64;
  	} iovu;
  #define iov iovu.iov64
  #define sizeof_iov \
  	(current_wordsize == 4 ? sizeof(*iovu.iov32) : sizeof(*iovu.iov64))
  #define iov_iov_base(i) \
  	(current_wordsize == 4 ? (uint64_t) iovu.iov32[i].base : iovu.iov64[i].base)
  #define iov_iov_len(i) \
  	(current_wordsize == 4 ? (uint64_t) iovu.iov32[i].len : iovu.iov64[i].len)
  #else
  	struct iovec *iov;
  #define sizeof_iov sizeof(*iov)
  #define iov_iov_base(i) iov[i].iov_base
  #define iov_iov_len(i) iov[i].iov_len
  #endif
  	int i;
  	unsigned size;
  
  	size = sizeof_iov * len;
  	/* Assuming no sane program has millions of iovs */
  	if ((unsigned)len > 1024*1024 /* insane or negative size? */
  	    || (iov = malloc(size)) == NULL) {
  		fprintf(stderr, "Out of memory\n");
  		return;
  	}
  	if (umoven(tcp, addr, size, (char *) iov) >= 0) {
  		for (i = 0; i < len; i++) {
  			/* include the buffer number to make it easy to
  			 * match up the trace with the source */
  			tprintf(" * %lu bytes in buffer %d\n",
  				(unsigned long)iov_iov_len(i), i);
  			dumpstr(tcp, (long) iov_iov_base(i),
  				iov_iov_len(i));
  		}
  	}
  	free(iov);
  #undef sizeof_iov
  #undef iov_iov_base
  #undef iov_iov_len
  #undef iov
  }
  
  void
  dumpstr(struct tcb *tcp, long addr, int len)
  {
  	static int strsize = -1;
  	static unsigned char *str;
  
  	char outbuf[
  		(
  			(sizeof(
  			"xx xx xx xx xx xx xx xx  xx xx xx xx xx xx xx xx  "
  			"1234567890123456") + /*in case I'm off by few:*/ 4)
  		/*align to 8 to make memset easier:*/ + 7) & -8
  	];
  	const unsigned char *src;
  	int i;
  
  	memset(outbuf, ' ', sizeof(outbuf));
  
  	if (strsize < len + 16) {
  		free(str);
  		str = malloc(len + 16);
  		if (!str) {
  			strsize = -1;
  			fprintf(stderr, "Out of memory\n");
  			return;
  		}
  		strsize = len + 16;
  	}
  
  	if (umoven(tcp, addr, len, (char *) str) < 0)
  		return;
  
  	/* Space-pad to 16 bytes */
  	i = len;
  	while (i & 0xf)
  		str[i++] = ' ';
  
  	i = 0;
  	src = str;
  	while (i < len) {
  		char *dst = outbuf;
  		/* Hex dump */
  		do {
  			if (i < len) {
  				*dst++ = "0123456789abcdef"[*src >> 4];
  				*dst++ = "0123456789abcdef"[*src & 0xf];
  			}
  			else {
  				*dst++ = ' ';
  				*dst++ = ' ';
  			}
  			dst++; /* space is there by memset */
  			i++;
  			if ((i & 7) == 0)
  				dst++; /* space is there by memset */
  			src++;
  		} while (i & 0xf);
  		/* ASCII dump */
  		i -= 16;
  		src -= 16;
  		do {
  			if (*src >= ' ' && *src < 0x7f)
  				*dst++ = *src;
  			else
  				*dst++ = '.';
  			src++;
  		} while (++i & 0xf);
  		*dst = '\0';
  		tprintf(" | %05x  %s |\n", i - 16, outbuf);
  	}
  }
  
  #ifdef HAVE_PROCESS_VM_READV
  /* C library supports this, but the kernel might not. */
  static bool process_vm_readv_not_supported = 0;
  #else
  
  /* Need to do this since process_vm_readv() is not yet available in libc.
   * When libc is be updated, only "static bool process_vm_readv_not_supported"
   * line should remain.
   */
  #if !defined(__NR_process_vm_readv)
  # if defined(I386)
  #  define __NR_process_vm_readv  347
  # elif defined(X86_64)
  #  define __NR_process_vm_readv  310
  # elif defined(POWERPC)
  #  define __NR_process_vm_readv  351
  # endif
  #endif
  
  #if defined(__NR_process_vm_readv)
  static bool process_vm_readv_not_supported = 0;
  /* Have to avoid duplicating with the C library headers. */
  static ssize_t strace_process_vm_readv(pid_t pid,
  		 const struct iovec *lvec,
  		 unsigned long liovcnt,
  		 const struct iovec *rvec,
  		 unsigned long riovcnt,
  		 unsigned long flags)
  {
  	return syscall(__NR_process_vm_readv, (long)pid, lvec, liovcnt, rvec, riovcnt, flags);
  }
  #define process_vm_readv strace_process_vm_readv
  #else
  static bool process_vm_readv_not_supported = 1;
  # define process_vm_readv(...) (errno = ENOSYS, -1)
  #endif
  
  #endif /* end of hack */
  
  #define PAGMASK	(~(PAGSIZ - 1))
  /*
   * move `len' bytes of data from process `pid'
   * at address `addr' to our space at `laddr'
   */
  int
  umoven(struct tcb *tcp, long addr, int len, char *laddr)
  {
  	int pid = tcp->pid;
  	int n, m, nread;
  	union {
  		long val;
  		char x[sizeof(long)];
  	} u;
  
  #if SUPPORTED_PERSONALITIES > 1 && SIZEOF_LONG > 4
  	if (current_wordsize < sizeof(addr))
  		addr &= (1ul << 8 * current_wordsize) - 1;
  #endif
  
  	if (!process_vm_readv_not_supported) {
  		struct iovec local[1], remote[1];
  		int r;
  
  		local[0].iov_base = laddr;
  		remote[0].iov_base = (void*)addr;
  		local[0].iov_len = remote[0].iov_len = len;
  		r = process_vm_readv(pid, local, 1, remote, 1, 0);
  		if (r == len)
  			return 0;
  		if (r >= 0) {
  			error_msg("umoven: short read (%d < %d) @0x%lx",
  				  r, len, addr);
  			return -1;
  		}
  		switch (errno) {
  			case ENOSYS:
  				process_vm_readv_not_supported = 1;
  				break;
  			case ESRCH:
  				/* the process is gone */
  				return -1;
  			case EFAULT: case EIO: case EPERM:
  				/* address space is inaccessible */
  				return -1;
  			default:
  				/* all the rest is strange and should be reported */
  				perror_msg("process_vm_readv");
  				return -1;
  		}
  	}
  
  	nread = 0;
  	if (addr & (sizeof(long) - 1)) {
  		/* addr not a multiple of sizeof(long) */
  		n = addr - (addr & -sizeof(long)); /* residue */
  		addr &= -sizeof(long); /* residue */
  		errno = 0;
  		u.val = ptrace(PTRACE_PEEKDATA, pid, (char *) addr, 0);
  		switch (errno) {
  			case 0:
  				break;
  			case ESRCH: case EINVAL:
  				/* these could be seen if the process is gone */
  				return -1;
  			case EFAULT: case EIO: case EPERM:
  				/* address space is inaccessible */
  				return -1;
  			default:
  				/* all the rest is strange and should be reported */
  				perror_msg("umoven: PTRACE_PEEKDATA pid:%d @0x%lx",
  					    pid, addr);
  				return -1;
  		}
  		m = MIN(sizeof(long) - n, len);
  		memcpy(laddr, &u.x[n], m);
  		addr += sizeof(long);
  		laddr += m;
  		nread += m;
  		len -= m;
  	}
  	while (len) {
  		errno = 0;
  		u.val = ptrace(PTRACE_PEEKDATA, pid, (char *) addr, 0);
  		switch (errno) {
  			case 0:
  				break;
  			case ESRCH: case EINVAL:
  				/* these could be seen if the process is gone */
  				return -1;
  			case EFAULT: case EIO: case EPERM:
  				/* address space is inaccessible */
  				if (nread) {
  					perror_msg("umoven: short read (%d < %d) @0x%lx",
  						   nread, nread + len, addr - nread);
  				}
  				return -1;
  			default:
  				/* all the rest is strange and should be reported */
  				perror_msg("umoven: PTRACE_PEEKDATA pid:%d @0x%lx",
  					    pid, addr);
  				return -1;
  		}
  		m = MIN(sizeof(long), len);
  		memcpy(laddr, u.x, m);
  		addr += sizeof(long);
  		laddr += m;
  		nread += m;
  		len -= m;
  	}
  
  	return 0;
  }
  
  /*
   * Like `umove' but make the additional effort of looking
   * for a terminating zero byte.
   *
   * Returns < 0 on error, > 0 if NUL was seen,
   * (TODO if useful: return count of bytes including NUL),
   * else 0 if len bytes were read but no NUL byte seen.
   *
   * Note: there is no guarantee we won't overwrite some bytes
   * in laddr[] _after_ terminating NUL (but, of course,
   * we never write past laddr[len-1]).
   */
  int
  umovestr(struct tcb *tcp, long addr, int len, char *laddr)
  {
  #if SIZEOF_LONG == 4
  	const unsigned long x01010101 = 0x01010101ul;
  	const unsigned long x80808080 = 0x80808080ul;
  #elif SIZEOF_LONG == 8
  	const unsigned long x01010101 = 0x0101010101010101ul;
  	const unsigned long x80808080 = 0x8080808080808080ul;
  #else
  # error SIZEOF_LONG > 8
  #endif
  
  	int pid = tcp->pid;
  	int n, m, nread;
  	union {
  		unsigned long val;
  		char x[sizeof(long)];
  	} u;
  
  #if SUPPORTED_PERSONALITIES > 1 && SIZEOF_LONG > 4
  	if (current_wordsize < sizeof(addr))
  		addr &= (1ul << 8 * current_wordsize) - 1;
  #endif
  
  	nread = 0;
  	if (!process_vm_readv_not_supported) {
  		struct iovec local[1], remote[1];
  
  		local[0].iov_base = laddr;
  		remote[0].iov_base = (void*)addr;
  
  		while (len > 0) {
  			int end_in_page;
  			int r;
  			int chunk_len;
  
  			/* Don't read kilobytes: most strings are short */
  			chunk_len = len;
  			if (chunk_len > 256)
  				chunk_len = 256;
  			/* Don't cross pages. I guess otherwise we can get EFAULT
  			 * and fail to notice that terminating NUL lies
  			 * in the existing (first) page.
  			 * (I hope there aren't arches with pages < 4K)
  			 */
  			end_in_page = ((addr + chunk_len) & 4095);
  			r = chunk_len - end_in_page;
  			if (r > 0) /* if chunk_len > end_in_page */
  				chunk_len = r; /* chunk_len -= end_in_page */
  
  			local[0].iov_len = remote[0].iov_len = chunk_len;
  			r = process_vm_readv(pid, local, 1, remote, 1, 0);
  			if (r > 0) {
  				if (memchr(local[0].iov_base, '\0', r))
  					return 1;
  				local[0].iov_base += r;
  				remote[0].iov_base += r;
  				len -= r;
  				nread += r;
  				continue;
  			}
  			switch (errno) {
  				case ENOSYS:
  					process_vm_readv_not_supported = 1;
  					goto vm_readv_didnt_work;
  				case ESRCH:
  					/* the process is gone */
  					return -1;
  				case EFAULT: case EIO: case EPERM:
  					/* address space is inaccessible */
  					if (nread) {
  						perror_msg("umovestr: short read (%d < %d) @0x%lx",
  							   nread, nread + len, addr);
  					}
  					return -1;
  				default:
  					/* all the rest is strange and should be reported */
  					perror_msg("process_vm_readv");
  					return -1;
  			}
  		}
  		return 0;
  	}
   vm_readv_didnt_work:
  
  	if (addr & (sizeof(long) - 1)) {
  		/* addr not a multiple of sizeof(long) */
  		n = addr - (addr & -sizeof(long)); /* residue */
  		addr &= -sizeof(long); /* residue */
  		errno = 0;
  		u.val = ptrace(PTRACE_PEEKDATA, pid, (char *)addr, 0);
  		switch (errno) {
  			case 0:
  				break;
  			case ESRCH: case EINVAL:
  				/* these could be seen if the process is gone */
  				return -1;
  			case EFAULT: case EIO: case EPERM:
  				/* address space is inaccessible */
  				return -1;
  			default:
  				/* all the rest is strange and should be reported */
  				perror_msg("umovestr: PTRACE_PEEKDATA pid:%d @0x%lx",
  					    pid, addr);
  				return -1;
  		}
  		m = MIN(sizeof(long) - n, len);
  		memcpy(laddr, &u.x[n], m);
  		while (n & (sizeof(long) - 1))
  			if (u.x[n++] == '\0')
  				return 1;
  		addr += sizeof(long);
  		laddr += m;
  		nread += m;
  		len -= m;
  	}
  
  	while (len) {
  		errno = 0;
  		u.val = ptrace(PTRACE_PEEKDATA, pid, (char *)addr, 0);
  		switch (errno) {
  			case 0:
  				break;
  			case ESRCH: case EINVAL:
  				/* these could be seen if the process is gone */
  				return -1;
  			case EFAULT: case EIO: case EPERM:
  				/* address space is inaccessible */
  				if (nread) {
  					perror_msg("umovestr: short read (%d < %d) @0x%lx",
  						   nread, nread + len, addr - nread);
  				}
  				return -1;
  			default:
  				/* all the rest is strange and should be reported */
  				perror_msg("umovestr: PTRACE_PEEKDATA pid:%d @0x%lx",
  					   pid, addr);
  				return -1;
  		}
  		m = MIN(sizeof(long), len);
  		memcpy(laddr, u.x, m);
  		/* "If a NUL char exists in this word" */
  		if ((u.val - x01010101) & ~u.val & x80808080)
  			return 1;
  		addr += sizeof(long);
  		laddr += m;
  		nread += m;
  		len -= m;
  	}
  	return 0;
  }
  
  int
  upeek(int pid, long off, long *res)
  {
  	long val;
  
  	errno = 0;
  	val = ptrace(PTRACE_PEEKUSER, (pid_t)pid, (char *) off, 0);
  	if (val == -1 && errno) {
  		if (errno != ESRCH) {
  			perror_msg("upeek: PTRACE_PEEKUSER pid:%d @0x%lx)", pid, off);
  		}
  		return -1;
  	}
  	*res = val;
  	return 0;
  }
  
  /* Note! On new kernels (about 2.5.46+), we use PTRACE_O_TRACECLONE
   * and PTRACE_O_TRACE[V]FORK for tracing children.
   * If you are adding a new arch which is only supported by newer kernels,
   * you most likely don't need to add any code below
   * beside a dummy "return 0" block in change_syscall().
   */
  
  /*
   * These #if's are huge, please indent them correctly.
   * It's easy to get confused otherwise.
   */
  
  #include "syscall.h"
  
  #ifndef CLONE_PTRACE
  # define CLONE_PTRACE    0x00002000
  #endif
  #ifndef CLONE_VFORK
  # define CLONE_VFORK     0x00004000
  #endif
  #ifndef CLONE_VM
  # define CLONE_VM        0x00000100
  #endif
  
  #ifdef IA64
  
  typedef unsigned long *arg_setup_state;
  
  static int
  arg_setup(struct tcb *tcp, arg_setup_state *state)
  {
  	unsigned long cfm, sof, sol;
  	long bsp;
  
  	if (ia64_ia32mode) {
  		/* Satisfy a false GCC warning.  */
  		*state = NULL;
  		return 0;
  	}
  
  	if (upeek(tcp->pid, PT_AR_BSP, &bsp) < 0)
  		return -1;
  	if (upeek(tcp->pid, PT_CFM, (long *) &cfm) < 0)
  		return -1;
  
  	sof = (cfm >> 0) & 0x7f;
  	sol = (cfm >> 7) & 0x7f;
  	bsp = (long) ia64_rse_skip_regs((unsigned long *) bsp, -sof + sol);
  
  	*state = (unsigned long *) bsp;
  	return 0;
  }
  
  # define arg_finish_change(tcp, state)	0
  
  static int
  get_arg0(struct tcb *tcp, arg_setup_state *state, long *valp)
  {
  	int ret;
  
  	if (ia64_ia32mode)
  		ret = upeek(tcp->pid, PT_R11, valp);
  	else
  		ret = umoven(tcp,
  			      (unsigned long) ia64_rse_skip_regs(*state, 0),
  			      sizeof(long), (void *) valp);
  	return ret;
  }
  
  static int
  get_arg1(struct tcb *tcp, arg_setup_state *state, long *valp)
  {
  	int ret;
  
  	if (ia64_ia32mode)
  		ret = upeek(tcp->pid, PT_R9, valp);
  	else
  		ret = umoven(tcp,
  			      (unsigned long) ia64_rse_skip_regs(*state, 1),
  			      sizeof(long), (void *) valp);
  	return ret;
  }
  
  static int
  set_arg0(struct tcb *tcp, arg_setup_state *state, long val)
  {
  	int req = PTRACE_POKEDATA;
  	void *ap;
  
  	if (ia64_ia32mode) {
  		ap = (void *) (intptr_t) PT_R11;	 /* r11 == EBX */
  		req = PTRACE_POKEUSER;
  	} else
  		ap = ia64_rse_skip_regs(*state, 0);
  	errno = 0;
  	ptrace(req, tcp->pid, ap, val);
  	return errno ? -1 : 0;
  }
  
  static int
  set_arg1(struct tcb *tcp, arg_setup_state *state, long val)
  {
  	int req = PTRACE_POKEDATA;
  	void *ap;
  
  	if (ia64_ia32mode) {
  		ap = (void *) (intptr_t) PT_R9;		/* r9 == ECX */
  		req = PTRACE_POKEUSER;
  	} else
  		ap = ia64_rse_skip_regs(*state, 1);
  	errno = 0;
  	ptrace(req, tcp->pid, ap, val);
  	return errno ? -1 : 0;
  }
  
  /* ia64 does not return the input arguments from functions (and syscalls)
     according to ia64 RSE (Register Stack Engine) behavior.  */
  
  # define restore_arg0(tcp, state, val) ((void) (state), 0)
  # define restore_arg1(tcp, state, val) ((void) (state), 0)
  
  #elif defined(SPARC) || defined(SPARC64)
  
  # if defined(SPARC64)
  #  undef PTRACE_GETREGS
  #  define PTRACE_GETREGS PTRACE_GETREGS64
  #  undef PTRACE_SETREGS
  #  define PTRACE_SETREGS PTRACE_SETREGS64
  # endif
  
  typedef struct pt_regs arg_setup_state;
  
  # define arg_setup(tcp, state) \
      (ptrace(PTRACE_GETREGS, (tcp)->pid, (char *) (state), 0))
  # define arg_finish_change(tcp, state) \
      (ptrace(PTRACE_SETREGS, (tcp)->pid, (char *) (state), 0))
  
  # define get_arg0(tcp, state, valp) (*(valp) = (state)->u_regs[U_REG_O0], 0)
  # define get_arg1(tcp, state, valp) (*(valp) = (state)->u_regs[U_REG_O1], 0)
  # define set_arg0(tcp, state, val)  ((state)->u_regs[U_REG_O0] = (val), 0)
  # define set_arg1(tcp, state, val)  ((state)->u_regs[U_REG_O1] = (val), 0)
  # define restore_arg0(tcp, state, val) 0
  
  #else /* other architectures */
  
  # if defined S390 || defined S390X
  /* Note: this is only true for the `clone' system call, which handles
     arguments specially.  We could as well say that its first two arguments
     are swapped relative to other architectures, but that would just be
     another #ifdef in the calls.  */
  #  define arg0_offset	PT_GPR3
  #  define arg1_offset	PT_ORIGGPR2
  #  define restore_arg0(tcp, state, val) ((void) (state), 0)
  #  define restore_arg1(tcp, state, val) ((void) (state), 0)
  #  define arg0_index	1
  #  define arg1_index	0
  # elif defined(ALPHA) || defined(MIPS)
  #  define arg0_offset	REG_A0
  #  define arg1_offset	(REG_A0+1)
  # elif defined(POWERPC)
  #  define arg0_offset	(sizeof(unsigned long)*PT_R3)
  #  define arg1_offset	(sizeof(unsigned long)*PT_R4)
  #  define restore_arg0(tcp, state, val) ((void) (state), 0)
  # elif defined(HPPA)
  #  define arg0_offset	PT_GR26
  #  define arg1_offset	(PT_GR26-4)
  # elif defined(X86_64) || defined(X32)
  #  define arg0_offset	((long)(8*(current_personality ? RBX : RDI)))
  #  define arg1_offset	((long)(8*(current_personality ? RCX : RSI)))
  # elif defined(SH)
  #  define arg0_offset	(4*(REG_REG0+4))
  #  define arg1_offset	(4*(REG_REG0+5))
  # elif defined(SH64)
     /* ABI defines arg0 & 1 in r2 & r3 */
  #  define arg0_offset	(REG_OFFSET+16)
  #  define arg1_offset	(REG_OFFSET+24)
  #  define restore_arg0(tcp, state, val) 0
  # elif defined CRISV10 || defined CRISV32
  #  define arg0_offset	(4*PT_R11)
  #  define arg1_offset	(4*PT_ORIG_R10)
  #  define restore_arg0(tcp, state, val) 0
  #  define restore_arg1(tcp, state, val) 0
  #  define arg0_index	1
  #  define arg1_index	0
  # else
  #  define arg0_offset	0
  #  define arg1_offset	4
  #  if defined ARM
  #   define restore_arg0(tcp, state, val) 0
  #  endif
  # endif
  
  typedef int arg_setup_state;
  
  # define arg_setup(tcp, state)         (0)
  # define arg_finish_change(tcp, state) 0
  # define get_arg0(tcp, cookie, valp)   (upeek((tcp)->pid, arg0_offset, (valp)))
  # define get_arg1(tcp, cookie, valp)   (upeek((tcp)->pid, arg1_offset, (valp)))
  
  static int
  set_arg0(struct tcb *tcp, void *cookie, long val)
  {
  	return ptrace(PTRACE_POKEUSER, tcp->pid, (char*)arg0_offset, val);
  }
  
  static int
  set_arg1(struct tcb *tcp, void *cookie, long val)
  {
  	return ptrace(PTRACE_POKEUSER, tcp->pid, (char*)arg1_offset, val);
  }
  
  #endif /* architectures */
  
  #ifndef restore_arg0
  # define restore_arg0(tcp, state, val) set_arg0((tcp), (state), (val))
  #endif
  #ifndef restore_arg1
  # define restore_arg1(tcp, state, val) set_arg1((tcp), (state), (val))
  #endif
  
  #ifndef arg0_index
  # define arg0_index 0
  # define arg1_index 1
  #endif
  
  static int
  change_syscall(struct tcb *tcp, arg_setup_state *state, int new)
  {
  #if defined(I386)
  	if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(ORIG_EAX * 4), new) < 0)
  		return -1;
  	return 0;
  #elif defined(X86_64)
  	if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(ORIG_RAX * 8), new) < 0)
  		return -1;
  	return 0;
  #elif defined(X32)
  	/* setbpt/clearbpt never used: */
  	/* X32 is only supported since about linux-3.0.30 */
  #elif defined(POWERPC)
  	if (ptrace(PTRACE_POKEUSER, tcp->pid,
  		   (char*)(sizeof(unsigned long)*PT_R0), new) < 0)
  		return -1;
  	return 0;
  #elif defined(S390) || defined(S390X)
  	/* s390 linux after 2.4.7 has a hook in entry.S to allow this */
  	if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(PT_GPR2), new) < 0)
  		return -1;
  	return 0;
  #elif defined(M68K)
  	if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(4*PT_ORIG_D0), new) < 0)
  		return -1;
  	return 0;
  #elif defined(SPARC) || defined(SPARC64)
  	state->u_regs[U_REG_G1] = new;
  	return 0;
  #elif defined(MIPS)
  	if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(REG_V0), new) < 0)
  		return -1;
  	return 0;
  #elif defined(ALPHA)
  	if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(REG_A3), new) < 0)
  		return -1;
  	return 0;
  #elif defined(AVR32)
  	/* setbpt/clearbpt never used: */
  	/* AVR32 is only supported since about linux-2.6.19 */
  #elif defined(BFIN)
  	/* setbpt/clearbpt never used: */
  	/* Blackfin is only supported since about linux-2.6.23 */
  #elif defined(IA64)
  	if (ia64_ia32mode) {
  		switch (new) {
  		case 2:
  			break;	/* x86 SYS_fork */
  		case SYS_clone:
  			new = 120;
  			break;
  		default:
  			fprintf(stderr, "%s: unexpected syscall %d\n",
  				__FUNCTION__, new);
  			return -1;
  		}
  		if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(PT_R1), new) < 0)
  			return -1;
  	} else if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(PT_R15), new) < 0)
  		return -1;
  	return 0;
  #elif defined(HPPA)
  	if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(PT_GR20), new) < 0)
  		return -1;
  	return 0;
  #elif defined(SH)
  	if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(4*(REG_REG0+3)), new) < 0)
  		return -1;
  	return 0;
  #elif defined(SH64)
  	/* Top half of reg encodes the no. of args n as 0x1n.
  	   Assume 0 args as kernel never actually checks... */
  	if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(REG_SYSCALL),
  				0x100000 | new) < 0)
  		return -1;
  	return 0;
  #elif defined(CRISV10) || defined(CRISV32)
  	if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(4*PT_R9), new) < 0)
  		return -1;
  	return 0;
  #elif defined(ARM)
  	/* Some kernels support this, some (pre-2.6.16 or so) don't.  */
  # ifndef PTRACE_SET_SYSCALL
  #  define PTRACE_SET_SYSCALL 23
  # endif
  	if (ptrace(PTRACE_SET_SYSCALL, tcp->pid, 0, new & 0xffff) != 0)
  		return -1;
  	return 0;
  #elif defined(AARCH64)
  	/* setbpt/clearbpt never used: */
  	/* AARCH64 is only supported since about linux-3.0.31 */
  #elif defined(TILE)
  	/* setbpt/clearbpt never used: */
  	/* Tilera CPUs are only supported since about linux-2.6.34 */
  #elif defined(MICROBLAZE)
  	/* setbpt/clearbpt never used: */
  	/* microblaze is only supported since about linux-2.6.30 */
  #elif defined(OR1K)
  	/* never reached; OR1K is only supported by kernels since 3.1.0. */
  #elif defined(METAG)
  	/* setbpt/clearbpt never used: */
  	/* Meta is only supported since linux-3.7 */
  #elif defined(XTENSA)
  	/* setbpt/clearbpt never used: */
  	/* Xtensa is only supported since linux 2.6.13 */
  #elif defined(ARC)
  	/* setbpt/clearbpt never used: */
  	/* ARC only supported since 3.9 */
  #else
  #warning Do not know how to handle change_syscall for this architecture
  #endif /* architecture */
  	return -1;
  }
  
  int
  setbpt(struct tcb *tcp)
  {
  	static int clone_scno[SUPPORTED_PERSONALITIES] = { SYS_clone };
  	arg_setup_state state;
  
  	if (tcp->flags & TCB_BPTSET) {
  		fprintf(stderr, "PANIC: TCB already set in pid %u\n", tcp->pid);
  		return -1;
  	}
  
  	/*
  	 * It's a silly kludge to initialize this with a search at runtime.
  	 * But it's better than maintaining another magic thing in the
  	 * godforsaken tables.
  	 */
  	if (clone_scno[current_personality] == 0) {
  		unsigned int i;
  		for (i = 0; i < nsyscalls; ++i)
  			if (sysent[i].sys_func == sys_clone) {
  				clone_scno[current_personality] = i;
  				break;
  			}
  	}
  
  	if (tcp->s_ent->sys_func == sys_fork) {
  		if (arg_setup(tcp, &state) < 0
  		    || get_arg0(tcp, &state, &tcp->inst[0]) < 0
  		    || get_arg1(tcp, &state, &tcp->inst[1]) < 0
  		    || change_syscall(tcp, &state,
  				      clone_scno[current_personality]) < 0
  		    || set_arg0(tcp, &state, CLONE_PTRACE|SIGCHLD) < 0
  		    || set_arg1(tcp, &state, 0) < 0
  		    || arg_finish_change(tcp, &state) < 0)
  			return -1;
  		tcp->u_arg[arg0_index] = CLONE_PTRACE|SIGCHLD;
  		tcp->u_arg[arg1_index] = 0;
  		tcp->flags |= TCB_BPTSET;
  		return 0;
  	}
  
  	if (tcp->s_ent->sys_func == sys_clone) {
  		/* ia64 calls directly `clone (CLONE_VFORK | CLONE_VM)'
  		   contrary to x86 vfork above.  Even on x86 we turn the
  		   vfork semantics into plain fork - each application must not
  		   depend on the vfork specifics according to POSIX.  We would
  		   hang waiting for the parent resume otherwise.  We need to
  		   clear also CLONE_VM but only in the CLONE_VFORK case as
  		   otherwise we would break pthread_create.  */
  
  		long new_arg0 = (tcp->u_arg[arg0_index] | CLONE_PTRACE);
  		if (new_arg0 & CLONE_VFORK)
  			new_arg0 &= ~(unsigned long)(CLONE_VFORK | CLONE_VM);
  		if (arg_setup(tcp, &state) < 0
  		 || set_arg0(tcp, &state, new_arg0) < 0
  		 || arg_finish_change(tcp, &state) < 0)
  			return -1;
  		tcp->inst[0] = tcp->u_arg[arg0_index];
  		tcp->inst[1] = tcp->u_arg[arg1_index];
  		tcp->flags |= TCB_BPTSET;
  		return 0;
  	}
  
  	fprintf(stderr, "PANIC: setbpt for syscall %ld on %u???\n",
  		tcp->scno, tcp->pid);
  	return -1;
  }
  
  int
  clearbpt(struct tcb *tcp)
  {
  	arg_setup_state state;
  	if (arg_setup(tcp, &state) < 0
  	    || change_syscall(tcp, &state, tcp->scno) < 0
  	    || restore_arg0(tcp, &state, tcp->inst[0]) < 0
  	    || restore_arg1(tcp, &state, tcp->inst[1]) < 0
  	    || arg_finish_change(tcp, &state))
  		if (errno != ESRCH)
  			return -1;
  	tcp->flags &= ~TCB_BPTSET;
  	return 0;
  }
  