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>
 #ifdef HAVE_SYS_EPOLL_H
 # include <sys/epoll.h>
 #endif
 #ifdef HAVE_LINUX_PERF_EVENT_H
 # include  <linux/perf_event.h>
 #endif

 static const struct xlat fcntlcmds[] = {
 	XLAT(F_DUPFD),
 	XLAT(F_GETFD),
 	XLAT(F_SETFD),
 	XLAT(F_GETFL),
 	XLAT(F_SETFL),
 	XLAT(F_GETLK),
 	XLAT(F_SETLK),
 	XLAT(F_SETLKW),
 	XLAT(F_GETOWN),
 	XLAT(F_SETOWN),
 #ifdef F_RSETLK
 	XLAT(F_RSETLK),
 #endif
 #ifdef F_RSETLKW
 	XLAT(F_RSETLKW),
 #endif
 #ifdef F_RGETLK
 	XLAT(F_RGETLK),
 #endif
 #ifdef F_CNVT
 	XLAT(F_CNVT),
 #endif
 #ifdef F_SETSIG
 	XLAT(F_SETSIG),
 #endif
 #ifdef F_GETSIG
 	XLAT(F_GETSIG),
 #endif
 #ifdef F_CHKFL
 	XLAT(F_CHKFL),
 #endif
 #ifdef F_DUP2FD
 	XLAT(F_DUP2FD),
 #endif
 #ifdef F_ALLOCSP
 	XLAT(F_ALLOCSP),
 #endif
 #ifdef F_ISSTREAM
 	XLAT(F_ISSTREAM),
 #endif
 #ifdef F_PRIV
 	XLAT(F_PRIV),
 #endif
 #ifdef F_NPRIV
 	XLAT(F_NPRIV),
 #endif
 #ifdef F_QUOTACL
 	XLAT(F_QUOTACL),
 #endif
 #ifdef F_BLOCKS
 	XLAT(F_BLOCKS),
 #endif
 #ifdef F_BLKSIZE
 	XLAT(F_BLKSIZE),
 #endif
 #ifdef F_GETOWN
 	XLAT(F_GETOWN),
 #endif
 #ifdef F_SETOWN
 	XLAT(F_SETOWN),
 #endif
 #ifdef F_REVOKE
 	XLAT(F_REVOKE),
 #endif
 #ifdef F_SETLK
 	XLAT(F_SETLK),
 #endif
 #ifdef F_SETLKW
 	XLAT(F_SETLKW),
 #endif
 #ifdef F_GETLK
 	XLAT(F_GETLK),
 #endif
 #ifdef F_SETLK64
 	XLAT(F_SETLK64),
 #endif
 #ifdef F_SETLKW64
 	XLAT(F_SETLKW64),
 #endif
 #ifdef F_GETLK64
 	XLAT(F_GETLK64),
 #endif
 #ifdef F_SHARE
 	XLAT(F_SHARE),
 #endif
 #ifdef F_UNSHARE
 	XLAT(F_UNSHARE),
 #endif
 #ifdef F_SETLEASE
 	XLAT(F_SETLEASE),
 #endif
 #ifdef F_GETLEASE
 	XLAT(F_GETLEASE),
 #endif
 #ifdef F_NOTIFY
 	XLAT(F_NOTIFY),
 #endif
 #ifdef F_DUPFD_CLOEXEC
 	XLAT(F_DUPFD_CLOEXEC),
 #endif
 	XLAT_END
 };

 static const struct xlat fdflags[] = {
 #ifdef FD_CLOEXEC
 	XLAT(FD_CLOEXEC),
 #endif
 	XLAT_END
 };

 #ifdef LOCK_SH

 static const struct xlat flockcmds[] = {
 	XLAT(LOCK_SH),
 	XLAT(LOCK_EX),
 	XLAT(LOCK_NB),
 	XLAT(LOCK_UN),
 	XLAT_END
 };

 #endif /* LOCK_SH */

 static const struct xlat lockfcmds[] = {
 	XLAT(F_RDLCK),
 	XLAT(F_WRLCK),
 	XLAT(F_UNLCK),
 #ifdef F_EXLCK
 	XLAT(F_EXLCK),
 #endif
 #ifdef F_SHLCK
 	XLAT(F_SHLCK),
 #endif
 	XLAT_END
 };

 #ifdef F_NOTIFY
 static const struct xlat notifyflags[] = {
 #ifdef DN_ACCESS
 	XLAT(DN_ACCESS),
 #endif
 #ifdef DN_MODIFY
 	XLAT(DN_MODIFY),
 #endif
 #ifdef DN_CREATE
 	XLAT(DN_CREATE),
 #endif
 #ifdef DN_DELETE
 	XLAT(DN_DELETE),
 #endif
 #ifdef DN_RENAME
 	XLAT(DN_RENAME),
 #endif
 #ifdef DN_ATTRIB
 	XLAT(DN_ATTRIB),
 #endif
 #ifdef DN_MULTISHOT
 	XLAT(DN_MULTISHOT),
 #endif
 	XLAT_END
 };
 #endif

 static const struct xlat perf_event_open_flags[] = {
 #ifdef PERF_FLAG_FD_NO_GROUP
 	XLAT(PERF_FLAG_FD_NO_GROUP),
 #endif
 #ifdef PERF_FLAG_FD_OUTPUT
 	XLAT(PERF_FLAG_FD_OUTPUT),
 #endif
 #ifdef PERF_FLAG_PID_CGROUP
 	XLAT(PERF_FLAG_PID_CGROUP),
 #endif
 	XLAT_END
 };

 /*
  * 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(tcp, addr, &fl) < 0) {
 		tprints("{...}");
 		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;
 	int r;

 #if SUPPORTED_PERSONALITIES > 1
 	if (
 # if SIZEOF_OFF_T > SIZEOF_LONG
 	    current_personality > 0 &&
 #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;
 			r = umove(tcp, addr, &fl32);
 			if (r >= 0) {
 				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
 	{
 		r = umove(tcp, addr, &fl);
 	}
 	if (r < 0) {
 		tprints("{...}");
 		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("}");
 }

 int
 sys_fcntl(struct tcb *tcp)
 {
 	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

 int
 sys_flock(struct tcb *tcp)
 {
 	if (entering(tcp)) {
 		printfd(tcp, tcp->u_arg[0]);
 		tprints(", ");
 		printflags(flockcmds, tcp->u_arg[1], "LOCK_???");
 	}
 	return 0;
 }
 #endif /* LOCK_SH */

 int
 sys_close(struct tcb *tcp)
 {
 	if (entering(tcp)) {
 		printfd(tcp, tcp->u_arg[0]);
 	}
 	return 0;
 }

 static int
 do_dup2(struct tcb *tcp, int flags_arg)
 {
 	if (entering(tcp)) {
 		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 0;
 }

 int
 sys_dup2(struct tcb *tcp)
 {
 	return do_dup2(tcp, -1);
 }

 int
 sys_dup3(struct tcb *tcp)
 {
 	return do_dup2(tcp, 2);
 }

 #if defined(ALPHA)
 int
 sys_getdtablesize(struct tcb *tcp)
 {
 	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;
 	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;
 		fds = NULL;
 	}
 	/* 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 (fdsize > 0) {
 			fds = malloc(fdsize);
 			if (!fds)
 				die_out_of_memory();
 		}
 		for (i = 0; i < 3; i++) {
 			arg = args[i+1];
 			if (arg == 0) {
 				tprints(", NULL");
 				continue;
 			}
 			if (!verbose(tcp) || !fds) {
 				tprintf(", %#lx", arg);
 				continue;
 			}
 			if (umoven(tcp, arg, fdsize, (char *) fds) < 0) {
 				tprints(", [?]");
 				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);
 		if (!fds)
 			die_out_of_memory();

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

 			arg = args[i+1];
 			if (!arg || umoven(tcp, arg, fdsize, (char *) 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;
 }

 int
 sys_oldselect(struct tcb *tcp)
 {
 	long args[5];

 	if (umoven(tcp, tcp->u_arg[0], sizeof args, (char *) args) < 0) {
 		tprints("[...]");
 		return 0;
 	}
 	return decode_select(tcp, args, BITNESS_CURRENT);
 }

 #ifdef ALPHA
 int
 sys_osf_select(struct tcb *tcp)
 {
 	long *args = tcp->u_arg;
 	return decode_select(tcp, args, BITNESS_32);
 }
 #endif

 static const struct xlat epollctls[] = {
 #ifdef EPOLL_CTL_ADD
 	XLAT(EPOLL_CTL_ADD),
 #endif
 #ifdef EPOLL_CTL_MOD
 	XLAT(EPOLL_CTL_MOD),
 #endif
 #ifdef EPOLL_CTL_DEL
 	XLAT(EPOLL_CTL_DEL),
 #endif
 	XLAT_END
 };

 static const struct xlat epollevents[] = {
 #ifdef EPOLLIN
 	XLAT(EPOLLIN),
 #endif
 #ifdef EPOLLPRI
 	XLAT(EPOLLPRI),
 #endif
 #ifdef EPOLLOUT
 	XLAT(EPOLLOUT),
 #endif
 #ifdef EPOLLRDNORM
 	XLAT(EPOLLRDNORM),
 #endif
 #ifdef EPOLLRDBAND
 	XLAT(EPOLLRDBAND),
 #endif
 #ifdef EPOLLWRNORM
 	XLAT(EPOLLWRNORM),
 #endif
 #ifdef EPOLLWRBAND
 	XLAT(EPOLLWRBAND),
 #endif
 #ifdef EPOLLMSG
 	XLAT(EPOLLMSG),
 #endif
 #ifdef EPOLLERR
 	XLAT(EPOLLERR),
 #endif
 #ifdef EPOLLHUP
 	XLAT(EPOLLHUP),
 #endif
 #ifdef EPOLLRDHUP
 	XLAT(EPOLLRDHUP),
 #endif
 #ifdef EPOLLONESHOT
 	XLAT(EPOLLONESHOT),
 #endif
 #ifdef EPOLLET
 	XLAT(EPOLLET),
 #endif
 	XLAT_END
 };

 /* Not aliased to printargs_ld: we want it to have a distinct address */
 int
 sys_epoll_create(struct tcb *tcp)
 {
 	return printargs_ld(tcp);
 }

 static const struct xlat epollflags[] = {
 #ifdef EPOLL_CLOEXEC
 	XLAT(EPOLL_CLOEXEC),
 #endif
 #ifdef EPOLL_NONBLOCK
 	XLAT(EPOLL_NONBLOCK),
 #endif
 	XLAT_END
 };

 int
 sys_epoll_create1(struct tcb *tcp)
 {
 	if (entering(tcp))
 		printflags(epollflags, tcp->u_arg[0], "EPOLL_???");
 	return 0;
 }

 #ifdef HAVE_SYS_EPOLL_H
 static void
 print_epoll_event(struct epoll_event *ev)
 {
 	tprints("{");
 	printflags(epollevents, ev->events, "EPOLL???");
 	/* We cannot know what format the program uses, so print u32 and u64
 	   which will cover every value.  */
 	tprintf(", {u32=%" PRIu32 ", u64=%" PRIu64 "}}",
 		ev->data.u32, ev->data.u64);
 }
 #endif

 int
 sys_epoll_ctl(struct tcb *tcp)
 {
 	if (entering(tcp)) {
 		printfd(tcp, tcp->u_arg[0]);
 		tprints(", ");
 		printxval(epollctls, tcp->u_arg[1], "EPOLL_CTL_???");
 		tprints(", ");
 		printfd(tcp, tcp->u_arg[2]);
 		tprints(", ");
 		if (tcp->u_arg[3] == 0)
 			tprints("NULL");
 		else {
 #ifdef HAVE_SYS_EPOLL_H
 			struct epoll_event ev;
 			if (
 #ifdef EPOLL_CTL_DEL
 			    (tcp->u_arg[1] != EPOLL_CTL_DEL) &&
 #endif
 			    umove(tcp, tcp->u_arg[3], &ev) == 0)
 				print_epoll_event(&ev);
 			else
 #endif
 				tprintf("%lx", tcp->u_arg[3]);
 		}
 	}
 	return 0;
 }

 static void
 epoll_wait_common(struct tcb *tcp)
 {
 	if (entering(tcp)) {
 		printfd(tcp, tcp->u_arg[0]);
 		tprints(", ");
 	} else {
 		if (syserror(tcp))
 			tprintf("%lx", tcp->u_arg[1]);
 		else if (tcp->u_rval == 0)
 			tprints("{}");
 		else {
 #ifdef HAVE_SYS_EPOLL_H
 			struct epoll_event ev, *start, *cur, *end;
 			int failed = 0;

 			tprints("{");
 			start = (struct epoll_event *) tcp->u_arg[1];
 			end = start + tcp->u_rval;
 			for (cur = start; cur < end; ++cur) {
 				if (cur > start)
 					tprints(", ");
 				if (umove(tcp, (long) cur, &ev) == 0)
 					print_epoll_event(&ev);
 				else {
 					tprints("?");
 					failed = 1;
 					break;
 				}
 			}
 			tprints("}");
 			if (failed)
 				tprintf(" %#lx", (long) start);
 #else
 			tprints("{...}");
 #endif
 		}
 		tprintf(", %d, %d", (int) tcp->u_arg[2], (int) tcp->u_arg[3]);
 	}
 }

 int
 sys_epoll_wait(struct tcb *tcp)
 {
 	epoll_wait_common(tcp);
 	return 0;
 }

 int
 sys_epoll_pwait(struct tcb *tcp)
 {
 	epoll_wait_common(tcp);
 	if (exiting(tcp)) {
 		tprints(", ");
 		/* NB: kernel requires arg[5] == NSIG / 8 */
 		print_sigset_addr_len(tcp, tcp->u_arg[4], tcp->u_arg[5]);
 		tprintf(", %lu", tcp->u_arg[5]);
 	}
 	return 0;
 }

 int
 sys_select(struct tcb *tcp)
 {
 	return decode_select(tcp, tcp->u_arg, BITNESS_CURRENT);
 }

 int
 sys_pselect6(struct tcb *tcp)
 {
 	int rc = decode_select(tcp, tcp->u_arg, BITNESS_CURRENT);
 	if (entering(tcp)) {
 		long r;
 		struct {
 			unsigned long ptr;
 			unsigned long len;
 		} data;
 #if SUPPORTED_PERSONALITIES > 1 && SIZEOF_LONG > 4
 		if (current_wordsize == 4) {
 			struct {
 				uint32_t ptr;
 				uint32_t len;
 			} data32;
 			r = umove(tcp, tcp->u_arg[5], &data32);
 			data.ptr = data32.ptr;
 			data.len = data32.len;
 		} else
 #endif
 			r = umove(tcp, tcp->u_arg[5], &data);
 		if (r < 0)
 			tprintf(", %#lx", tcp->u_arg[5]);
 		else {
 			tprints(", {");
 			/* NB: kernel requires data.len == NSIG / 8 */
 			print_sigset_addr_len(tcp, data.ptr, data.len);
 			tprintf(", %lu}", data.len);
 		}
 	}
 	return rc;
 }

 static int
 do_eventfd(struct tcb *tcp, int flags_arg)
 {
 	if (entering(tcp)) {
 		tprintf("%lu", tcp->u_arg[0]);
 		if (flags_arg >= 0) {
 			tprints(", ");
 			printflags(open_mode_flags, tcp->u_arg[flags_arg], "O_???");
 		}
 	}
 	return 0;
 }

 int
 sys_eventfd(struct tcb *tcp)
 {
 	return do_eventfd(tcp, -1);
 }

 int
 sys_eventfd2(struct tcb *tcp)
 {
 	return do_eventfd(tcp, 1);
 }

 int
 sys_perf_event_open(struct tcb *tcp)
 {
 	if (entering(tcp)) {
 		tprintf("%#lx, %d, %d, %d, ",
 			tcp->u_arg[0],
 			(int) tcp->u_arg[1],
 			(int) tcp->u_arg[2],
 			(int) tcp->u_arg[3]);
 		printflags(perf_event_open_flags, tcp->u_arg[4],
 			   "PERF_FLAG_???");
 	}
 	return 0;
 }
	/*
	* 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>
	#ifdef HAVE_SYS_EPOLL_H
	# include <sys/epoll.h>
	#endif
	#ifdef HAVE_LINUX_PERF_EVENT_H
	# include <linux/perf_event.h>
	#endif

	static const struct xlat fcntlcmds[] = {
	XLAT(F_DUPFD),
	XLAT(F_GETFD),
	XLAT(F_SETFD),
	XLAT(F_GETFL),
	XLAT(F_SETFL),
	XLAT(F_GETLK),
	XLAT(F_SETLK),
	XLAT(F_SETLKW),
	XLAT(F_GETOWN),
	XLAT(F_SETOWN),
	#ifdef F_RSETLK
	XLAT(F_RSETLK),
	#endif
	#ifdef F_RSETLKW
	XLAT(F_RSETLKW),
	#endif
	#ifdef F_RGETLK
	XLAT(F_RGETLK),
	#endif
	#ifdef F_CNVT
	XLAT(F_CNVT),
	#endif
	#ifdef F_SETSIG
	XLAT(F_SETSIG),
	#endif
	#ifdef F_GETSIG
	XLAT(F_GETSIG),
	#endif
	#ifdef F_CHKFL
	XLAT(F_CHKFL),
	#endif
	#ifdef F_DUP2FD
	XLAT(F_DUP2FD),
	#endif
	#ifdef F_ALLOCSP
	XLAT(F_ALLOCSP),
	#endif
	#ifdef F_ISSTREAM
	XLAT(F_ISSTREAM),
	#endif
	#ifdef F_PRIV
	XLAT(F_PRIV),
	#endif
	#ifdef F_NPRIV
	XLAT(F_NPRIV),
	#endif
	#ifdef F_QUOTACL
	XLAT(F_QUOTACL),
	#endif
	#ifdef F_BLOCKS
	XLAT(F_BLOCKS),
	#endif
	#ifdef F_BLKSIZE
	XLAT(F_BLKSIZE),
	#endif
	#ifdef F_GETOWN
	XLAT(F_GETOWN),
	#endif
	#ifdef F_SETOWN
	XLAT(F_SETOWN),
	#endif
	#ifdef F_REVOKE
	XLAT(F_REVOKE),
	#endif
	#ifdef F_SETLK
	XLAT(F_SETLK),
	#endif
	#ifdef F_SETLKW
	XLAT(F_SETLKW),
	#endif
	#ifdef F_GETLK
	XLAT(F_GETLK),
	#endif
	#ifdef F_SETLK64
	XLAT(F_SETLK64),
	#endif
	#ifdef F_SETLKW64
	XLAT(F_SETLKW64),
	#endif
	#ifdef F_GETLK64
	XLAT(F_GETLK64),
	#endif
	#ifdef F_SHARE
	XLAT(F_SHARE),
	#endif
	#ifdef F_UNSHARE
	XLAT(F_UNSHARE),
	#endif
	#ifdef F_SETLEASE
	XLAT(F_SETLEASE),
	#endif
	#ifdef F_GETLEASE
	XLAT(F_GETLEASE),
	#endif
	#ifdef F_NOTIFY
	XLAT(F_NOTIFY),
	#endif
	#ifdef F_DUPFD_CLOEXEC
	XLAT(F_DUPFD_CLOEXEC),
	#endif
	XLAT_END
	};

	static const struct xlat fdflags[] = {
	#ifdef FD_CLOEXEC
	XLAT(FD_CLOEXEC),
	#endif
	XLAT_END
	};

	#ifdef LOCK_SH

	static const struct xlat flockcmds[] = {
	XLAT(LOCK_SH),
	XLAT(LOCK_EX),
	XLAT(LOCK_NB),
	XLAT(LOCK_UN),
	XLAT_END
	};

	#endif /* LOCK_SH */

	static const struct xlat lockfcmds[] = {
	XLAT(F_RDLCK),
	XLAT(F_WRLCK),
	XLAT(F_UNLCK),
	#ifdef F_EXLCK
	XLAT(F_EXLCK),
	#endif
	#ifdef F_SHLCK
	XLAT(F_SHLCK),
	#endif
	XLAT_END
	};

	#ifdef F_NOTIFY
	static const struct xlat notifyflags[] = {
	#ifdef DN_ACCESS
	XLAT(DN_ACCESS),
	#endif
	#ifdef DN_MODIFY
	XLAT(DN_MODIFY),
	#endif
	#ifdef DN_CREATE
	XLAT(DN_CREATE),
	#endif
	#ifdef DN_DELETE
	XLAT(DN_DELETE),
	#endif
	#ifdef DN_RENAME
	XLAT(DN_RENAME),
	#endif
	#ifdef DN_ATTRIB
	XLAT(DN_ATTRIB),
	#endif
	#ifdef DN_MULTISHOT
	XLAT(DN_MULTISHOT),
	#endif
	XLAT_END
	};
	#endif

	static const struct xlat perf_event_open_flags[] = {
	#ifdef PERF_FLAG_FD_NO_GROUP
	XLAT(PERF_FLAG_FD_NO_GROUP),
	#endif
	#ifdef PERF_FLAG_FD_OUTPUT
	XLAT(PERF_FLAG_FD_OUTPUT),
	#endif
	#ifdef PERF_FLAG_PID_CGROUP
	XLAT(PERF_FLAG_PID_CGROUP),
	#endif
	XLAT_END
	};

	/*
	* 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(tcp, addr, &fl) < 0) {
	tprints("{...}");
	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;
	int r;

	#if SUPPORTED_PERSONALITIES > 1
	if (
	# if SIZEOF_OFF_T > SIZEOF_LONG
	current_personality > 0 &&
	#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;
	r = umove(tcp, addr, &fl32);
	if (r >= 0) {
	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
	{
	r = umove(tcp, addr, &fl);
	}
	if (r < 0) {
	tprints("{...}");
	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("}");
	}

	int
	sys_fcntl(struct tcb *tcp)
	{
	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

	int
	sys_flock(struct tcb *tcp)
	{
	if (entering(tcp)) {
	printfd(tcp, tcp->u_arg[0]);
	tprints(", ");
	printflags(flockcmds, tcp->u_arg[1], "LOCK_???");
	}
	return 0;
	}
	#endif /* LOCK_SH */

	int
	sys_close(struct tcb *tcp)
	{
	if (entering(tcp)) {
	printfd(tcp, tcp->u_arg[0]);
	}
	return 0;
	}

	static int
	do_dup2(struct tcb *tcp, int flags_arg)
	{
	if (entering(tcp)) {
	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 0;
	}

	int
	sys_dup2(struct tcb *tcp)
	{
	return do_dup2(tcp, -1);
	}

	int
	sys_dup3(struct tcb *tcp)
	{
	return do_dup2(tcp, 2);
	}

	#if defined(ALPHA)
	int
	sys_getdtablesize(struct tcb *tcp)
	{
	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;
	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;
	fds = NULL;
	}
	/* 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 (fdsize > 0) {
	fds = malloc(fdsize);
	if (!fds)
	die_out_of_memory();
	}
	for (i = 0; i < 3; i++) {
	arg = args[i+1];
	if (arg == 0) {
	tprints(", NULL");
	continue;
	}
	if (!verbose(tcp) \|\| !fds) {
	tprintf(", %#lx", arg);
	continue;
	}
	if (umoven(tcp, arg, fdsize, (char *) fds) < 0) {
	tprints(", [?]");
	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);
	if (!fds)
	die_out_of_memory();

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

	arg = args[i+1];
	if (!arg \|\| umoven(tcp, arg, fdsize, (char *) 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;
	}

	int
	sys_oldselect(struct tcb *tcp)
	{
	long args[5];

	if (umoven(tcp, tcp->u_arg[0], sizeof args, (char *) args) < 0) {
	tprints("[...]");
	return 0;
	}
	return decode_select(tcp, args, BITNESS_CURRENT);
	}

	#ifdef ALPHA
	int
	sys_osf_select(struct tcb *tcp)
	{
	long *args = tcp->u_arg;
	return decode_select(tcp, args, BITNESS_32);
	}
	#endif

	static const struct xlat epollctls[] = {
	#ifdef EPOLL_CTL_ADD
	XLAT(EPOLL_CTL_ADD),
	#endif
	#ifdef EPOLL_CTL_MOD
	XLAT(EPOLL_CTL_MOD),
	#endif
	#ifdef EPOLL_CTL_DEL
	XLAT(EPOLL_CTL_DEL),
	#endif
	XLAT_END
	};

	static const struct xlat epollevents[] = {
	#ifdef EPOLLIN
	XLAT(EPOLLIN),
	#endif
	#ifdef EPOLLPRI
	XLAT(EPOLLPRI),
	#endif
	#ifdef EPOLLOUT
	XLAT(EPOLLOUT),
	#endif
	#ifdef EPOLLRDNORM
	XLAT(EPOLLRDNORM),
	#endif
	#ifdef EPOLLRDBAND
	XLAT(EPOLLRDBAND),
	#endif
	#ifdef EPOLLWRNORM
	XLAT(EPOLLWRNORM),
	#endif
	#ifdef EPOLLWRBAND
	XLAT(EPOLLWRBAND),
	#endif
	#ifdef EPOLLMSG
	XLAT(EPOLLMSG),
	#endif
	#ifdef EPOLLERR
	XLAT(EPOLLERR),
	#endif
	#ifdef EPOLLHUP
	XLAT(EPOLLHUP),
	#endif
	#ifdef EPOLLRDHUP
	XLAT(EPOLLRDHUP),
	#endif
	#ifdef EPOLLONESHOT
	XLAT(EPOLLONESHOT),
	#endif
	#ifdef EPOLLET
	XLAT(EPOLLET),
	#endif
	XLAT_END
	};

	/* Not aliased to printargs_ld: we want it to have a distinct address */
	int
	sys_epoll_create(struct tcb *tcp)
	{
	return printargs_ld(tcp);
	}

	static const struct xlat epollflags[] = {
	#ifdef EPOLL_CLOEXEC
	XLAT(EPOLL_CLOEXEC),
	#endif
	#ifdef EPOLL_NONBLOCK
	XLAT(EPOLL_NONBLOCK),
	#endif
	XLAT_END
	};

	int
	sys_epoll_create1(struct tcb *tcp)
	{
	if (entering(tcp))
	printflags(epollflags, tcp->u_arg[0], "EPOLL_???");
	return 0;
	}

	#ifdef HAVE_SYS_EPOLL_H
	static void
	print_epoll_event(struct epoll_event *ev)
	{
	tprints("{");
	printflags(epollevents, ev->events, "EPOLL???");
	/* We cannot know what format the program uses, so print u32 and u64
	which will cover every value. */
	tprintf(", {u32=%" PRIu32 ", u64=%" PRIu64 "}}",
	ev->data.u32, ev->data.u64);
	}
	#endif

	int
	sys_epoll_ctl(struct tcb *tcp)
	{
	if (entering(tcp)) {
	printfd(tcp, tcp->u_arg[0]);
	tprints(", ");
	printxval(epollctls, tcp->u_arg[1], "EPOLL_CTL_???");
	tprints(", ");
	printfd(tcp, tcp->u_arg[2]);
	tprints(", ");
	if (tcp->u_arg[3] == 0)
	tprints("NULL");
	else {
	#ifdef HAVE_SYS_EPOLL_H
	struct epoll_event ev;
	if (
	#ifdef EPOLL_CTL_DEL
	(tcp->u_arg[1] != EPOLL_CTL_DEL) &&
	#endif
	umove(tcp, tcp->u_arg[3], &ev) == 0)
	print_epoll_event(&ev);
	else
	#endif
	tprintf("%lx", tcp->u_arg[3]);
	}
	}
	return 0;
	}

	static void
	epoll_wait_common(struct tcb *tcp)
	{
	if (entering(tcp)) {
	printfd(tcp, tcp->u_arg[0]);
	tprints(", ");
	} else {
	if (syserror(tcp))
	tprintf("%lx", tcp->u_arg[1]);
	else if (tcp->u_rval == 0)
	tprints("{}");
	else {
	#ifdef HAVE_SYS_EPOLL_H
	struct epoll_event ev, start, cur, *end;
	int failed = 0;

	tprints("{");
	start = (struct epoll_event *) tcp->u_arg[1];
	end = start + tcp->u_rval;
	for (cur = start; cur < end; ++cur) {
	if (cur > start)
	tprints(", ");
	if (umove(tcp, (long) cur, &ev) == 0)
	print_epoll_event(&ev);
	else {
	tprints("?");
	failed = 1;
	break;
	}
	}
	tprints("}");
	if (failed)
	tprintf(" %#lx", (long) start);
	#else
	tprints("{...}");
	#endif
	}
	tprintf(", %d, %d", (int) tcp->u_arg[2], (int) tcp->u_arg[3]);
	}
	}

	int
	sys_epoll_wait(struct tcb *tcp)
	{
	epoll_wait_common(tcp);
	return 0;
	}

	int
	sys_epoll_pwait(struct tcb *tcp)
	{
	epoll_wait_common(tcp);
	if (exiting(tcp)) {
	tprints(", ");
	/* NB: kernel requires arg[5] == NSIG / 8 */
	print_sigset_addr_len(tcp, tcp->u_arg[4], tcp->u_arg[5]);
	tprintf(", %lu", tcp->u_arg[5]);
	}
	return 0;
	}

	int
	sys_select(struct tcb *tcp)
	{
	return decode_select(tcp, tcp->u_arg, BITNESS_CURRENT);
	}

	int
	sys_pselect6(struct tcb *tcp)
	{
	int rc = decode_select(tcp, tcp->u_arg, BITNESS_CURRENT);
	if (entering(tcp)) {
	long r;
	struct {
	unsigned long ptr;
	unsigned long len;
	} data;
	#if SUPPORTED_PERSONALITIES > 1 && SIZEOF_LONG > 4
	if (current_wordsize == 4) {
	struct {
	uint32_t ptr;
	uint32_t len;
	} data32;
	r = umove(tcp, tcp->u_arg[5], &data32);
	data.ptr = data32.ptr;
	data.len = data32.len;
	} else
	#endif
	r = umove(tcp, tcp->u_arg[5], &data);
	if (r < 0)
	tprintf(", %#lx", tcp->u_arg[5]);
	else {
	tprints(", {");
	/* NB: kernel requires data.len == NSIG / 8 */
	print_sigset_addr_len(tcp, data.ptr, data.len);
	tprintf(", %lu}", data.len);
	}
	}
	return rc;
	}

	static int
	do_eventfd(struct tcb *tcp, int flags_arg)
	{
	if (entering(tcp)) {
	tprintf("%lu", tcp->u_arg[0]);
	if (flags_arg >= 0) {
	tprints(", ");
	printflags(open_mode_flags, tcp->u_arg[flags_arg], "O_???");
	}
	}
	return 0;
	}

	int
	sys_eventfd(struct tcb *tcp)
	{
	return do_eventfd(tcp, -1);
	}

	int
	sys_eventfd2(struct tcb *tcp)
	{
	return do_eventfd(tcp, 1);
	}

	int
	sys_perf_event_open(struct tcb *tcp)
	{
	if (entering(tcp)) {
	tprintf("%#lx, %d, %d, %d, ",
	tcp->u_arg[0],
	(int) tcp->u_arg[1],
	(int) tcp->u_arg[2],
	(int) tcp->u_arg[3]);
	printflags(perf_event_open_flags, tcp->u_arg[4],
	"PERF_FLAG_???");
	}
	return 0;
	}