desc.c - platform/external/strace - Gitiles

 /*
  * 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>
  * 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 <fcntl.h>
 #include <sys/file.h>

 #include "xlat/fcntlcmds.h"
 #include "xlat/fdflags.h"
 #include "xlat/flockcmds.h"
 #include "xlat/lockfcmds.h"
 #include "xlat/notifyflags.h"

 /*
  * Assume that F_SETLK64, F_SETLKW64, and F_GETLK64 are either defined
  * or not defined altogether.
  */
 #if defined(F_SETLK64) && F_SETLK64 + 0 != F_SETLK
 # define USE_PRINTFLOCK64 1
 #else
 # define USE_PRINTFLOCK64 0
 #endif

 #if USE_PRINTFLOCK64

 # ifndef HAVE_STRUCT_FLOCK64
 struct flock64 {
 	short int l_type, l_whence;
 	int64_t l_start, l_len;
 	int l_pid;
 };
 # endif

 static void
 printflock64(struct tcb *tcp, long addr, int getlk)
 {
 	struct flock64 fl;

 	if (umove_or_printaddr(tcp, addr, &fl))
 		return;
 	tprints("{type=");
 	printxval(lockfcmds, fl.l_type, "F_???");
 	tprints(", whence=");
 	printxval(whence_codes, fl.l_whence, "SEEK_???");
 	tprintf(", start=%lld, len=%lld", (long long) fl.l_start, (long long) fl.l_len);
 	if (getlk)
 		tprintf(", pid=%lu}", (unsigned long) fl.l_pid);
 	else
 		tprints("}");
 }
 #endif /* USE_PRINTFLOCK64 */

 static void
 printflock(struct tcb *tcp, long addr, int getlk)
 {
 	struct flock fl;

 #if SUPPORTED_PERSONALITIES > 1
 	if (
 # if SIZEOF_OFF_T > SIZEOF_LONG
 	    current_personality != DEFAULT_PERSONALITY &&
 # endif
 	    current_wordsize != sizeof(fl.l_start)) {
 		if (current_wordsize == 4) {
 			/* 32-bit x86 app on x86_64 and similar cases */
 			struct {
 				short int l_type;
 				short int l_whence;
 				int32_t l_start; /* off_t */
 				int32_t l_len; /* off_t */
 				int32_t l_pid; /* pid_t */
 			} fl32;
 			if (umove_or_printaddr(tcp, addr, &fl32))
 				return;
 			fl.l_type = fl32.l_type;
 			fl.l_whence = fl32.l_whence;
 			fl.l_start = fl32.l_start;
 			fl.l_len = fl32.l_len;
 			fl.l_pid = fl32.l_pid;
 		} else {
 			/* let people know we have a problem here */
 			tprintf("<decode error: unsupported wordsize %d>",
 				current_wordsize);
 			return;
 		}
 	} else
 #endif
 	if (umove_or_printaddr(tcp, addr, &fl))
 		return;
 	tprints("{type=");
 	printxval(lockfcmds, fl.l_type, "F_???");
 	tprints(", whence=");
 	printxval(whence_codes, fl.l_whence, "SEEK_???");
 #if SIZEOF_OFF_T > SIZEOF_LONG
 	tprintf(", start=%lld, len=%lld", fl.l_start, fl.l_len);
 #else
 	tprintf(", start=%ld, len=%ld", fl.l_start, fl.l_len);
 #endif
 	if (getlk)
 		tprintf(", pid=%lu}", (unsigned long) fl.l_pid);
 	else
 		tprints("}");
 }

 SYS_FUNC(fcntl)
 {
 	if (entering(tcp)) {
 		printfd(tcp, tcp->u_arg[0]);
 		tprints(", ");
 		printxval(fcntlcmds, tcp->u_arg[1], "F_???");
 		switch (tcp->u_arg[1]) {
 		case F_SETFD:
 			tprints(", ");
 			printflags(fdflags, tcp->u_arg[2], "FD_???");
 			break;
 		case F_SETOWN: case F_DUPFD:
 #ifdef F_DUPFD_CLOEXEC
 		case F_DUPFD_CLOEXEC:
 #endif
 			tprintf(", %ld", tcp->u_arg[2]);
 			break;
 		case F_SETFL:
 			tprints(", ");
 			tprint_open_modes(tcp->u_arg[2]);
 			break;
 		case F_SETLK: case F_SETLKW:
 			tprints(", ");
 			printflock(tcp, tcp->u_arg[2], 0);
 			break;
 #if USE_PRINTFLOCK64
 		case F_SETLK64: case F_SETLKW64:
 			tprints(", ");
 			printflock64(tcp, tcp->u_arg[2], 0);
 			break;
 #endif /* USE_PRINTFLOCK64 */
 #ifdef F_NOTIFY
 		case F_NOTIFY:
 			tprints(", ");
 			printflags(notifyflags, tcp->u_arg[2], "DN_???");
 			break;
 #endif
 #ifdef F_SETLEASE
 		case F_SETLEASE:
 			tprints(", ");
 			printxval(lockfcmds, tcp->u_arg[2], "F_???");
 			break;
 #endif
 		}
 	} else {
 		switch (tcp->u_arg[1]) {
 		case F_DUPFD:
 #ifdef F_DUPFD_CLOEXEC
 		case F_DUPFD_CLOEXEC:
 #endif
 		case F_SETFD: case F_SETFL:
 		case F_SETLK: case F_SETLKW:
 		case F_SETOWN: case F_GETOWN:
 #ifdef F_NOTIFY
 		case F_NOTIFY:
 #endif
 #ifdef F_SETLEASE
 		case F_SETLEASE:
 #endif
 			break;
 		case F_GETFD:
 			if (syserror(tcp) || tcp->u_rval == 0)
 				return 0;
 			tcp->auxstr = sprintflags("flags ", fdflags, tcp->u_rval);
 			return RVAL_HEX|RVAL_STR;
 		case F_GETFL:
 			if (syserror(tcp))
 				return 0;
 			tcp->auxstr = sprint_open_modes(tcp->u_rval);
 			return RVAL_HEX|RVAL_STR;
 		case F_GETLK:
 			tprints(", ");
 			printflock(tcp, tcp->u_arg[2], 1);
 			break;
 #if USE_PRINTFLOCK64
 		case F_GETLK64:
 			tprints(", ");
 			printflock64(tcp, tcp->u_arg[2], 1);
 			break;
 #endif
 #ifdef F_GETLEASE
 		case F_GETLEASE:
 			if (syserror(tcp))
 				return 0;
 			tcp->auxstr = xlookup(lockfcmds, tcp->u_rval);
 			return RVAL_HEX|RVAL_STR;
 #endif
 		default:
 			tprintf(", %#lx", tcp->u_arg[2]);
 			break;
 		}
 	}
 	return 0;
 }

 #ifdef LOCK_SH

 SYS_FUNC(flock)
 {
 	printfd(tcp, tcp->u_arg[0]);
 	tprints(", ");
 	printflags(flockcmds, tcp->u_arg[1], "LOCK_???");

 	return RVAL_DECODED;
 }
 #endif /* LOCK_SH */

 SYS_FUNC(close)
 {
 	printfd(tcp, tcp->u_arg[0]);

 	return RVAL_DECODED;
 }

 SYS_FUNC(dup)
 {
 	printfd(tcp, tcp->u_arg[0]);

 	return RVAL_DECODED | RVAL_FD;
 }

 static int
 do_dup2(struct tcb *tcp, int flags_arg)
 {
 	printfd(tcp, tcp->u_arg[0]);
 	tprints(", ");
 	printfd(tcp, tcp->u_arg[1]);
 	if (flags_arg >= 0) {
 		tprints(", ");
 		printflags(open_mode_flags, tcp->u_arg[flags_arg], "O_???");
 	}

 	return RVAL_DECODED | RVAL_FD;
 }

 SYS_FUNC(dup2)
 {
 	return do_dup2(tcp, -1);
 }

 SYS_FUNC(dup3)
 {
 	return do_dup2(tcp, 2);
 }

 #if defined(ALPHA)
 SYS_FUNC(getdtablesize)
 {
 	return 0;
 }
 #endif

 static int
 decode_select(struct tcb *tcp, long *args, enum bitness_t bitness)
 {
 	int i, j;
 	int nfds, fdsize;
 	fd_set *fds = NULL;
 	const char *sep;
 	long arg;

 	/* Kernel truncates arg[0] to int, we do the same. */
 	nfds = (int) args[0];

 	/* Kernel rejects negative nfds, so we don't parse it either. */
 	if (nfds < 0)
 		nfds = 0;

 	/* Beware of select(2^31-1, NULL, NULL, NULL) and similar... */
 	if (nfds > 1024*1024)
 		nfds = 1024*1024;

 	/*
 	 * We had bugs a-la "while (j < args[0])" and "umoven(args[0])" below.
 	 * Instead of args[0], use nfds for fd count, fdsize for array lengths.
 	 */
 	fdsize = (((nfds + 7) / 8) + current_wordsize-1) & -current_wordsize;

 	if (entering(tcp)) {
 		tprintf("%d", (int) args[0]);

 		if (verbose(tcp) && fdsize > 0)
 			fds = malloc(fdsize);
 		for (i = 0; i < 3; i++) {
 			arg = args[i+1];
 			tprints(", ");
 			if (!fds) {
 				printaddr(arg);
 				continue;
 			}
 			if (umoven_or_printaddr(tcp, arg, fdsize, fds))
 				continue;
 			tprints("[");
 			for (j = 0, sep = "";; j++) {
 				j = next_set_bit(fds, j, nfds);
 				if (j < 0)
 					break;
 				tprints(sep);
 				printfd(tcp, j);
 				sep = " ";
 			}
 			tprints("]");
 		}
 		free(fds);
 		tprints(", ");
 		printtv_bitness(tcp, args[4], bitness, 0);
 	} else {
 		static char outstr[1024];
 		char *outptr;
 #define end_outstr (outstr + sizeof(outstr))
 		int ready_fds;

 		if (syserror(tcp))
 			return 0;

 		ready_fds = tcp->u_rval;
 		if (ready_fds == 0) {
 			tcp->auxstr = "Timeout";
 			return RVAL_STR;
 		}

 		fds = malloc(fdsize);

 		outptr = outstr;
 		sep = "";
 		for (i = 0; i < 3 && ready_fds > 0; i++) {
 			int first = 1;

 			arg = args[i+1];
 			if (!arg || !fds || umoven(tcp, arg, fdsize, fds) < 0)
 				continue;
 			for (j = 0;; j++) {
 				j = next_set_bit(fds, j, nfds);
 				if (j < 0)
 					break;
 				/* +2 chars needed at the end: ']',NUL */
 				if (outptr < end_outstr - (sizeof(", except [") + sizeof(int)*3 + 2)) {
 					if (first) {
 						outptr += sprintf(outptr, "%s%s [%u",
 							sep,
 							i == 0 ? "in" : i == 1 ? "out" : "except",
 							j
 						);
 						first = 0;
 						sep = ", ";
 					}
 					else {
 						outptr += sprintf(outptr, " %u", j);
 					}
 				}
 				if (--ready_fds == 0)
 					break;
 			}
 			if (outptr != outstr)
 				*outptr++ = ']';
 		}
 		free(fds);
 		/* This contains no useful information on SunOS.  */
 		if (args[4]) {
 			if (outptr < end_outstr - (10 + TIMEVAL_TEXT_BUFSIZE)) {
 				outptr += sprintf(outptr, "%sleft ", sep);
 				outptr = sprinttv(outptr, tcp, args[4], bitness, /*special:*/ 0);
 			}
 		}
 		*outptr = '\0';
 		tcp->auxstr = outstr;
 		return RVAL_STR;
 #undef end_outstr
 	}
 	return 0;
 }

 SYS_FUNC(oldselect)
 {
 	long long_args[5];
 #undef oldselect_args
 #if SIZEOF_LONG == 4
 # define oldselect_args long_args
 #else
 	unsigned int oldselect_args[5];
 	unsigned int i;
 #endif

 	if (umove(tcp, tcp->u_arg[0], &oldselect_args) < 0) {
 		printaddr(tcp->u_arg[0]);
 		return 0;
 	}
 #ifndef oldselect_args
 	for (i = 0; i < 5; i++) {
 		long_args[i] = oldselect_args[i];
 	}
 #endif
 	return decode_select(tcp, long_args, BITNESS_CURRENT);
 #undef oldselect_args
 }

 #ifdef ALPHA
 SYS_FUNC(osf_select)
 {
 	return decode_select(tcp, tcp->u_arg, BITNESS_32);
 }
 #endif

 SYS_FUNC(select)
 {
 	return decode_select(tcp, tcp->u_arg, BITNESS_CURRENT);
 }

 SYS_FUNC(pselect6)
 {
 	int rc = decode_select(tcp, tcp->u_arg, BITNESS_CURRENT);
 	if (entering(tcp)) {
 		long r;
 		struct {
 			unsigned long ptr;
 			unsigned long len;
 		} data;

 		tprints(", ");
 #if SUPPORTED_PERSONALITIES > 1 && SIZEOF_LONG > 4
 		if (current_wordsize == 4) {
 			struct {
 				uint32_t ptr;
 				uint32_t len;
 			} data32;
 			r = umove_or_printaddr(tcp, tcp->u_arg[5], &data32);
 			data.ptr = data32.ptr;
 			data.len = data32.len;
 		} else
 #endif
 			r = umove_or_printaddr(tcp, tcp->u_arg[5], &data);
 		if (r == 0) {
 			tprints("{");
 			/* NB: kernel requires data.len == NSIG / 8 */
 			print_sigset_addr_len(tcp, data.ptr, data.len);
 			tprintf(", %lu}", data.len);
 		}
 	}
 	return rc;
 }
	/*
	* 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>
	* 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 <fcntl.h>
	#include <sys/file.h>

	#include "xlat/fcntlcmds.h"
	#include "xlat/fdflags.h"
	#include "xlat/flockcmds.h"
	#include "xlat/lockfcmds.h"
	#include "xlat/notifyflags.h"

	/*
	* Assume that F_SETLK64, F_SETLKW64, and F_GETLK64 are either defined
	* or not defined altogether.
	*/
	#if defined(F_SETLK64) && F_SETLK64 + 0 != F_SETLK
	# define USE_PRINTFLOCK64 1
	#else
	# define USE_PRINTFLOCK64 0
	#endif

	#if USE_PRINTFLOCK64

	# ifndef HAVE_STRUCT_FLOCK64
	struct flock64 {
	short int l_type, l_whence;
	int64_t l_start, l_len;
	int l_pid;
	};
	# endif

	static void
	printflock64(struct tcb *tcp, long addr, int getlk)
	{
	struct flock64 fl;

	if (umove_or_printaddr(tcp, addr, &fl))
	return;
	tprints("{type=");
	printxval(lockfcmds, fl.l_type, "F_???");
	tprints(", whence=");
	printxval(whence_codes, fl.l_whence, "SEEK_???");
	tprintf(", start=%lld, len=%lld", (long long) fl.l_start, (long long) fl.l_len);
	if (getlk)
	tprintf(", pid=%lu}", (unsigned long) fl.l_pid);
	else
	tprints("}");
	}
	#endif /* USE_PRINTFLOCK64 */

	static void
	printflock(struct tcb *tcp, long addr, int getlk)
	{
	struct flock fl;

	#if SUPPORTED_PERSONALITIES > 1
	if (
	# if SIZEOF_OFF_T > SIZEOF_LONG
	current_personality != DEFAULT_PERSONALITY &&
	# endif
	current_wordsize != sizeof(fl.l_start)) {
	if (current_wordsize == 4) {
	/* 32-bit x86 app on x86_64 and similar cases */
	struct {
	short int l_type;
	short int l_whence;
	int32_t l_start; /* off_t */
	int32_t l_len; /* off_t */
	int32_t l_pid; /* pid_t */
	} fl32;
	if (umove_or_printaddr(tcp, addr, &fl32))
	return;
	fl.l_type = fl32.l_type;
	fl.l_whence = fl32.l_whence;
	fl.l_start = fl32.l_start;
	fl.l_len = fl32.l_len;
	fl.l_pid = fl32.l_pid;
	} else {
	/* let people know we have a problem here */
	tprintf("<decode error: unsupported wordsize %d>",
	current_wordsize);
	return;
	}
	} else
	#endif
	if (umove_or_printaddr(tcp, addr, &fl))
	return;
	tprints("{type=");
	printxval(lockfcmds, fl.l_type, "F_???");
	tprints(", whence=");
	printxval(whence_codes, fl.l_whence, "SEEK_???");
	#if SIZEOF_OFF_T > SIZEOF_LONG
	tprintf(", start=%lld, len=%lld", fl.l_start, fl.l_len);
	#else
	tprintf(", start=%ld, len=%ld", fl.l_start, fl.l_len);
	#endif
	if (getlk)
	tprintf(", pid=%lu}", (unsigned long) fl.l_pid);
	else
	tprints("}");
	}

	SYS_FUNC(fcntl)
	{
	if (entering(tcp)) {
	printfd(tcp, tcp->u_arg[0]);
	tprints(", ");
	printxval(fcntlcmds, tcp->u_arg[1], "F_???");
	switch (tcp->u_arg[1]) {
	case F_SETFD:
	tprints(", ");
	printflags(fdflags, tcp->u_arg[2], "FD_???");
	break;
	case F_SETOWN: case F_DUPFD:
	#ifdef F_DUPFD_CLOEXEC
	case F_DUPFD_CLOEXEC:
	#endif
	tprintf(", %ld", tcp->u_arg[2]);
	break;
	case F_SETFL:
	tprints(", ");
	tprint_open_modes(tcp->u_arg[2]);
	break;
	case F_SETLK: case F_SETLKW:
	tprints(", ");
	printflock(tcp, tcp->u_arg[2], 0);
	break;
	#if USE_PRINTFLOCK64
	case F_SETLK64: case F_SETLKW64:
	tprints(", ");
	printflock64(tcp, tcp->u_arg[2], 0);
	break;
	#endif /* USE_PRINTFLOCK64 */
	#ifdef F_NOTIFY
	case F_NOTIFY:
	tprints(", ");
	printflags(notifyflags, tcp->u_arg[2], "DN_???");
	break;
	#endif
	#ifdef F_SETLEASE
	case F_SETLEASE:
	tprints(", ");
	printxval(lockfcmds, tcp->u_arg[2], "F_???");
	break;
	#endif
	}
	} else {
	switch (tcp->u_arg[1]) {
	case F_DUPFD:
	#ifdef F_DUPFD_CLOEXEC
	case F_DUPFD_CLOEXEC:
	#endif
	case F_SETFD: case F_SETFL:
	case F_SETLK: case F_SETLKW:
	case F_SETOWN: case F_GETOWN:
	#ifdef F_NOTIFY
	case F_NOTIFY:
	#endif
	#ifdef F_SETLEASE
	case F_SETLEASE:
	#endif
	break;
	case F_GETFD:
	if (syserror(tcp) \|\| tcp->u_rval == 0)
	return 0;
	tcp->auxstr = sprintflags("flags ", fdflags, tcp->u_rval);
	return RVAL_HEX\|RVAL_STR;
	case F_GETFL:
	if (syserror(tcp))
	return 0;
	tcp->auxstr = sprint_open_modes(tcp->u_rval);
	return RVAL_HEX\|RVAL_STR;
	case F_GETLK:
	tprints(", ");
	printflock(tcp, tcp->u_arg[2], 1);
	break;
	#if USE_PRINTFLOCK64
	case F_GETLK64:
	tprints(", ");
	printflock64(tcp, tcp->u_arg[2], 1);
	break;
	#endif
	#ifdef F_GETLEASE
	case F_GETLEASE:
	if (syserror(tcp))
	return 0;
	tcp->auxstr = xlookup(lockfcmds, tcp->u_rval);
	return RVAL_HEX\|RVAL_STR;
	#endif
	default:
	tprintf(", %#lx", tcp->u_arg[2]);
	break;
	}
	}
	return 0;
	}

	#ifdef LOCK_SH

	SYS_FUNC(flock)
	{
	printfd(tcp, tcp->u_arg[0]);
	tprints(", ");
	printflags(flockcmds, tcp->u_arg[1], "LOCK_???");

	return RVAL_DECODED;
	}
	#endif /* LOCK_SH */

	SYS_FUNC(close)
	{
	printfd(tcp, tcp->u_arg[0]);

	return RVAL_DECODED;
	}

	SYS_FUNC(dup)
	{
	printfd(tcp, tcp->u_arg[0]);

	return RVAL_DECODED \| RVAL_FD;
	}

	static int
	do_dup2(struct tcb *tcp, int flags_arg)
	{
	printfd(tcp, tcp->u_arg[0]);
	tprints(", ");
	printfd(tcp, tcp->u_arg[1]);
	if (flags_arg >= 0) {
	tprints(", ");
	printflags(open_mode_flags, tcp->u_arg[flags_arg], "O_???");
	}

	return RVAL_DECODED \| RVAL_FD;
	}

	SYS_FUNC(dup2)
	{
	return do_dup2(tcp, -1);
	}

	SYS_FUNC(dup3)
	{
	return do_dup2(tcp, 2);
	}

	#if defined(ALPHA)
	SYS_FUNC(getdtablesize)
	{
	return 0;
	}
	#endif

	static int
	decode_select(struct tcb tcp, long args, enum bitness_t bitness)
	{
	int i, j;
	int nfds, fdsize;
	fd_set *fds = NULL;
	const char *sep;
	long arg;

	/* Kernel truncates arg[0] to int, we do the same. */
	nfds = (int) args[0];

	/* Kernel rejects negative nfds, so we don't parse it either. */
	if (nfds < 0)
	nfds = 0;

	/* Beware of select(2^31-1, NULL, NULL, NULL) and similar... */
	if (nfds > 1024*1024)
	nfds = 1024*1024;

	/*
	* We had bugs a-la "while (j < args[0])" and "umoven(args[0])" below.
	* Instead of args[0], use nfds for fd count, fdsize for array lengths.
	*/
	fdsize = (((nfds + 7) / 8) + current_wordsize-1) & -current_wordsize;

	if (entering(tcp)) {
	tprintf("%d", (int) args[0]);

	if (verbose(tcp) && fdsize > 0)
	fds = malloc(fdsize);
	for (i = 0; i < 3; i++) {
	arg = args[i+1];
	tprints(", ");
	if (!fds) {
	printaddr(arg);
	continue;
	}
	if (umoven_or_printaddr(tcp, arg, fdsize, fds))
	continue;
	tprints("[");
	for (j = 0, sep = "";; j++) {
	j = next_set_bit(fds, j, nfds);
	if (j < 0)
	break;
	tprints(sep);
	printfd(tcp, j);
	sep = " ";
	}
	tprints("]");
	}
	free(fds);
	tprints(", ");
	printtv_bitness(tcp, args[4], bitness, 0);
	} else {
	static char outstr[1024];
	char *outptr;
	#define end_outstr (outstr + sizeof(outstr))
	int ready_fds;

	if (syserror(tcp))
	return 0;

	ready_fds = tcp->u_rval;
	if (ready_fds == 0) {
	tcp->auxstr = "Timeout";
	return RVAL_STR;
	}

	fds = malloc(fdsize);

	outptr = outstr;
	sep = "";
	for (i = 0; i < 3 && ready_fds > 0; i++) {
	int first = 1;

	arg = args[i+1];
	if (!arg \|\| !fds \|\| umoven(tcp, arg, fdsize, fds) < 0)
	continue;
	for (j = 0;; j++) {
	j = next_set_bit(fds, j, nfds);
	if (j < 0)
	break;
	/* +2 chars needed at the end: ']',NUL */
	if (outptr < end_outstr - (sizeof(", except [") + sizeof(int)*3 + 2)) {
	if (first) {
	outptr += sprintf(outptr, "%s%s [%u",
	sep,
	i == 0 ? "in" : i == 1 ? "out" : "except",
	j
	);
	first = 0;
	sep = ", ";
	}
	else {
	outptr += sprintf(outptr, " %u", j);
	}
	}
	if (--ready_fds == 0)
	break;
	}
	if (outptr != outstr)
	*outptr++ = ']';
	}
	free(fds);
	/* This contains no useful information on SunOS. */
	if (args[4]) {
	if (outptr < end_outstr - (10 + TIMEVAL_TEXT_BUFSIZE)) {
	outptr += sprintf(outptr, "%sleft ", sep);
	outptr = sprinttv(outptr, tcp, args[4], bitness, /special:/ 0);
	}
	}
	*outptr = '\0';
	tcp->auxstr = outstr;
	return RVAL_STR;
	#undef end_outstr
	}
	return 0;
	}

	SYS_FUNC(oldselect)
	{
	long long_args[5];
	#undef oldselect_args
	#if SIZEOF_LONG == 4
	# define oldselect_args long_args
	#else
	unsigned int oldselect_args[5];
	unsigned int i;
	#endif

	if (umove(tcp, tcp->u_arg[0], &oldselect_args) < 0) {
	printaddr(tcp->u_arg[0]);
	return 0;
	}
	#ifndef oldselect_args
	for (i = 0; i < 5; i++) {
	long_args[i] = oldselect_args[i];
	}
	#endif
	return decode_select(tcp, long_args, BITNESS_CURRENT);
	#undef oldselect_args
	}

	#ifdef ALPHA
	SYS_FUNC(osf_select)
	{
	return decode_select(tcp, tcp->u_arg, BITNESS_32);
	}
	#endif

	SYS_FUNC(select)
	{
	return decode_select(tcp, tcp->u_arg, BITNESS_CURRENT);
	}

	SYS_FUNC(pselect6)
	{
	int rc = decode_select(tcp, tcp->u_arg, BITNESS_CURRENT);
	if (entering(tcp)) {
	long r;
	struct {
	unsigned long ptr;
	unsigned long len;
	} data;

	tprints(", ");
	#if SUPPORTED_PERSONALITIES > 1 && SIZEOF_LONG > 4
	if (current_wordsize == 4) {
	struct {
	uint32_t ptr;
	uint32_t len;
	} data32;
	r = umove_or_printaddr(tcp, tcp->u_arg[5], &data32);
	data.ptr = data32.ptr;
	data.len = data32.len;
	} else
	#endif
	r = umove_or_printaddr(tcp, tcp->u_arg[5], &data);
	if (r == 0) {
	tprints("{");
	/* NB: kernel requires data.len == NSIG / 8 */
	print_sigset_addr_len(tcp, data.ptr, data.len);
	tprintf(", %lu}", data.len);
	}
	}
	return rc;
	}