/*--------------------------------------------------------------------*/
/*--- Linux-specific syscalls, etc.                syswrap-linux.c ---*/
/*--------------------------------------------------------------------*/

/*
   This file is part of Valgrind, a dynamic binary instrumentation
   framework.

   Copyright (C) 2000-2005 Nicholas Nethercote
      njn@valgrind.org

   This program is free software; you can redistribute it and/or
   modify it under the terms of the GNU General Public License as
   published by the Free Software Foundation; either version 2 of the
   License, or (at your option) any later version.

   This program is distributed in the hope that it will be useful, but
   WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307, USA.

   The GNU General Public License is contained in the file COPYING.
*/

#include "pub_core_basics.h"
#include "pub_core_threadstate.h"
#include "pub_core_debuginfo.h"     // Needed for pub_core_aspacemgr :(
#include "pub_core_aspacemgr.h"
#include "pub_core_debuglog.h"
#include "pub_core_libcbase.h"
#include "pub_core_libcassert.h"
#include "pub_core_libcfile.h"
#include "pub_core_libcprint.h"
#include "pub_core_libcproc.h"
#include "pub_core_mallocfree.h"
#include "pub_core_tooliface.h"
#include "pub_core_options.h"
#include "pub_core_scheduler.h"
#include "pub_core_signals.h"
#include "pub_core_syscall.h"

#include "priv_types_n_macros.h"
#include "priv_syswrap-generic.h"
#include "priv_syswrap-linux.h"

// Run a thread from beginning to end and return the thread's
// scheduler-return-code.
VgSchedReturnCode ML_(thread_wrapper)(Word /*ThreadId*/ tidW)
{
   VG_(debugLog)(1, "core_os", 
                    "ML_(thread_wrapper)(tid=%lld): entry\n", 
                    (ULong)tidW);

   VgSchedReturnCode ret;
   ThreadId     tid = (ThreadId)tidW;
   ThreadState* tst = VG_(get_ThreadState)(tid);

   vg_assert(tst->status == VgTs_Init);

   /* make sure we get the CPU lock before doing anything significant */
   VG_(set_running)(tid);

   if (0)
      VG_(printf)("thread tid %d started: stack = %p\n",
		  tid, &tid);

   VG_TRACK ( post_thread_create, tst->os_state.parent, tid );

   tst->os_state.lwpid = VG_(gettid)();
   tst->os_state.threadgroup = VG_(getpid)();

   /* Thread created with all signals blocked; scheduler will set the
      appropriate mask */

   ret = VG_(scheduler)(tid);

   vg_assert(VG_(is_exiting)(tid));
   
   vg_assert(tst->status == VgTs_Runnable);
   vg_assert(VG_(is_running_thread)(tid));

   VG_(debugLog)(1, "core_os", 
                    "ML_(thread_wrapper)(tid=%lld): done\n", 
                    (ULong)tidW);

   /* Return to caller, still holding the lock. */
   return ret;
}


/* ---------------------------------------------------------------------
   PRE/POST wrappers for arch-generic, Linux-specific syscalls
   ------------------------------------------------------------------ */

// Nb: See the comment above the generic PRE/POST wrappers in
// m_syswrap/syswrap-generic.c for notes about how they work.

#define PRE(name)       DEFN_PRE_TEMPLATE(linux, name)
#define POST(name)      DEFN_POST_TEMPLATE(linux, name)

// Combine two 32-bit values into a 64-bit value
#define LOHI64(lo,hi)   ( (lo) | ((ULong)(hi) << 32) )

/* ---------------------------------------------------------------------
   *mount wrappers
   ------------------------------------------------------------------ */

PRE(sys_mount)
{
   // Nb: depending on 'flags', the 'type' and 'data' args may be ignored.
   // We are conservative and check everything, except the memory pointed to
   // by 'data'.
   *flags |= SfMayBlock;
   PRINT( "sys_mount( %p, %p, %p, %p, %p )" ,ARG1,ARG2,ARG3,ARG4,ARG5);
   PRE_REG_READ5(long, "mount",
                 char *, source, char *, target, char *, type,
                 unsigned long, flags, void *, data);
   PRE_MEM_RASCIIZ( "mount(source)", ARG1);
   PRE_MEM_RASCIIZ( "mount(target)", ARG2);
   PRE_MEM_RASCIIZ( "mount(type)", ARG3);
}

PRE(sys_oldumount)
{
   PRINT("sys_oldumount( %p )", ARG1);
   PRE_REG_READ1(long, "umount", char *, path);
   PRE_MEM_RASCIIZ( "umount(path)", ARG1);
}

PRE(sys_umount)
{
   PRINT("sys_umount( %p, %d )", ARG1, ARG2);
   PRE_REG_READ2(long, "umount2", char *, path, int, flags);
   PRE_MEM_RASCIIZ( "umount2(path)", ARG1);
}

/* ---------------------------------------------------------------------
   16- and 32-bit uid/gid wrappers
   ------------------------------------------------------------------ */

PRE(sys_setfsuid16)
{
   PRINT("sys_setfsuid16 ( %d )", ARG1);
   PRE_REG_READ1(long, "setfsuid16", vki_old_uid_t, uid);
}

PRE(sys_setfsuid)
{
   PRINT("sys_setfsuid ( %d )", ARG1);
   PRE_REG_READ1(long, "setfsuid", vki_uid_t, uid);
}

PRE(sys_setfsgid16)
{
   PRINT("sys_setfsgid16 ( %d )", ARG1);
   PRE_REG_READ1(long, "setfsgid16", vki_old_gid_t, gid);
}

PRE(sys_setfsgid)
{
   PRINT("sys_setfsgid ( %d )", ARG1);
   PRE_REG_READ1(long, "setfsgid", vki_gid_t, gid);
}

PRE(sys_setresuid16)
{
   PRINT("sys_setresuid16 ( %d, %d, %d )", ARG1, ARG2, ARG3);
   PRE_REG_READ3(long, "setresuid16",
                 vki_old_uid_t, ruid, vki_old_uid_t, euid, vki_old_uid_t, suid);
}

PRE(sys_setresuid)
{
   PRINT("sys_setresuid ( %d, %d, %d )", ARG1, ARG2, ARG3);
   PRE_REG_READ3(long, "setresuid",
                 vki_uid_t, ruid, vki_uid_t, euid, vki_uid_t, suid);
}

PRE(sys_getresuid16)
{
   PRINT("sys_getresuid16 ( %p, %p, %p )", ARG1,ARG2,ARG3);
   PRE_REG_READ3(long, "getresuid16",
                 vki_old_uid_t *, ruid, vki_old_uid_t *, euid,
                 vki_old_uid_t *, suid);
   PRE_MEM_WRITE( "getresuid16(ruid)", ARG1, sizeof(vki_old_uid_t) );
   PRE_MEM_WRITE( "getresuid16(euid)", ARG2, sizeof(vki_old_uid_t) );
   PRE_MEM_WRITE( "getresuid16(suid)", ARG3, sizeof(vki_old_uid_t) );
}
POST(sys_getresuid16)
{
   vg_assert(SUCCESS);
   if (RES == 0) {
      POST_MEM_WRITE( ARG1, sizeof(vki_old_uid_t) );
      POST_MEM_WRITE( ARG2, sizeof(vki_old_uid_t) );
      POST_MEM_WRITE( ARG3, sizeof(vki_old_uid_t) );
   }
}

PRE(sys_getresuid)
{
   PRINT("sys_getresuid ( %p, %p, %p )", ARG1,ARG2,ARG3);
   PRE_REG_READ3(long, "getresuid", 
                 vki_uid_t *, ruid, vki_uid_t *, euid, vki_uid_t *, suid);
   PRE_MEM_WRITE( "getresuid(ruid)", ARG1, sizeof(vki_uid_t) );
   PRE_MEM_WRITE( "getresuid(euid)", ARG2, sizeof(vki_uid_t) );
   PRE_MEM_WRITE( "getresuid(suid)", ARG3, sizeof(vki_uid_t) );
}
POST(sys_getresuid)
{
   vg_assert(SUCCESS);
   if (RES == 0) {
      POST_MEM_WRITE( ARG1, sizeof(vki_uid_t) );
      POST_MEM_WRITE( ARG2, sizeof(vki_uid_t) );
      POST_MEM_WRITE( ARG3, sizeof(vki_uid_t) );
   }
}

PRE(sys_setresgid16)
{
   PRINT("sys_setresgid16 ( %d, %d, %d )", ARG1, ARG2, ARG3);
   PRE_REG_READ3(long, "setresgid16",
                 vki_old_gid_t, rgid, 
                 vki_old_gid_t, egid, vki_old_gid_t, sgid);
}

PRE(sys_setresgid)
{
   PRINT("sys_setresgid ( %d, %d, %d )", ARG1, ARG2, ARG3);
   PRE_REG_READ3(long, "setresgid",
                 vki_gid_t, rgid, vki_gid_t, egid, vki_gid_t, sgid);
}

PRE(sys_getresgid16)
{
   PRINT("sys_getresgid16 ( %p, %p, %p )", ARG1,ARG2,ARG3);
   PRE_REG_READ3(long, "getresgid16",
                 vki_old_gid_t *, rgid, vki_old_gid_t *, egid,
                 vki_old_gid_t *, sgid);
   PRE_MEM_WRITE( "getresgid16(rgid)", ARG1, sizeof(vki_old_gid_t) );
   PRE_MEM_WRITE( "getresgid16(egid)", ARG2, sizeof(vki_old_gid_t) );
   PRE_MEM_WRITE( "getresgid16(sgid)", ARG3, sizeof(vki_old_gid_t) );
}
POST(sys_getresgid16)
{
   vg_assert(SUCCESS);
   if (RES == 0) {
      POST_MEM_WRITE( ARG1, sizeof(vki_old_gid_t) );
      POST_MEM_WRITE( ARG2, sizeof(vki_old_gid_t) );
      POST_MEM_WRITE( ARG3, sizeof(vki_old_gid_t) );
   }
}

PRE(sys_getresgid)
{
   PRINT("sys_getresgid ( %p, %p, %p )", ARG1,ARG2,ARG3);
   PRE_REG_READ3(long, "getresgid", 
                 vki_gid_t *, rgid, vki_gid_t *, egid, vki_gid_t *, sgid);
   PRE_MEM_WRITE( "getresgid(rgid)", ARG1, sizeof(vki_gid_t) );
   PRE_MEM_WRITE( "getresgid(egid)", ARG2, sizeof(vki_gid_t) );
   PRE_MEM_WRITE( "getresgid(sgid)", ARG3, sizeof(vki_gid_t) );
}
POST(sys_getresgid)
{
   vg_assert(SUCCESS);
   if (RES == 0) {
      POST_MEM_WRITE( ARG1, sizeof(vki_gid_t) );
      POST_MEM_WRITE( ARG2, sizeof(vki_gid_t) );
      POST_MEM_WRITE( ARG3, sizeof(vki_gid_t) );
   }
}

/* ---------------------------------------------------------------------
   miscellaneous wrappers
   ------------------------------------------------------------------ */

PRE(sys_exit_group)
{
   ThreadId     t;
   ThreadState* tst;

   PRINT("exit_group( %d )", ARG1);
   PRE_REG_READ1(void, "exit_group", int, exit_code);

   tst = VG_(get_ThreadState)(tid);

   /* A little complex; find all the threads with the same threadgroup
      as this one (including this one), and mark them to exit */
   for (t = 1; t < VG_N_THREADS; t++) {
      if ( /* not alive */
           VG_(threads)[t].status == VgTs_Empty 
           ||
	   /* not our group */
           VG_(threads)[t].os_state.threadgroup != tst->os_state.threadgroup
         )
         continue;

      VG_(threads)[t].exitreason = VgSrc_ExitSyscall;
      VG_(threads)[t].os_state.exitcode = ARG1;

      if (t != tid)
	 VG_(kill_thread)(t);	/* unblock it, if blocked */
   }

   /* We have to claim the syscall already succeeded. */
   SET_STATUS_Success(0);
}

PRE(sys_llseek)
{
   PRINT("sys_llseek ( %d, 0x%x, 0x%x, %p, %d )", ARG1,ARG2,ARG3,ARG4,ARG5);
   PRE_REG_READ5(long, "llseek",
                 unsigned int, fd, unsigned long, offset_high,
                 unsigned long, offset_low, vki_loff_t *, result,
                 unsigned int, whence);
   PRE_MEM_WRITE( "llseek(result)", ARG4, sizeof(vki_loff_t));
}
POST(sys_llseek)
{
   vg_assert(SUCCESS);
   if (RES == 0)
      POST_MEM_WRITE( ARG4, sizeof(vki_loff_t) );
}

//zz PRE(sys_adjtimex, 0)
//zz {
//zz    struct vki_timex *tx = (struct vki_timex *)ARG1;
//zz    PRINT("sys_adjtimex ( %p )", ARG1);
//zz    PRE_REG_READ1(long, "adjtimex", struct timex *, buf);
//zz    PRE_MEM_READ( "adjtimex(timex->modes)", ARG1, sizeof(tx->modes));
//zz 
#if 0 //zz  (avoiding warnings about multi-line comments)
zz #define ADJX(bit,field) 				\
zz    if (tx->modes & bit)					\
zz       PRE_MEM_READ( "adjtimex(timex->"#field")",	\
zz 		    (Addr)&tx->field, sizeof(tx->field))
#endif
//zz    ADJX(ADJ_FREQUENCY, freq);
//zz    ADJX(ADJ_MAXERROR, maxerror);
//zz    ADJX(ADJ_ESTERROR, esterror);
//zz    ADJX(ADJ_STATUS, status);
//zz    ADJX(ADJ_TIMECONST, constant);
//zz    ADJX(ADJ_TICK, tick);
//zz #undef ADJX
//zz    
//zz    PRE_MEM_WRITE( "adjtimex(timex)", ARG1, sizeof(struct vki_timex));
//zz }
//zz 
//zz POST(sys_adjtimex)
//zz {
//zz    POST_MEM_WRITE( ARG1, sizeof(struct vki_timex) );
//zz }

PRE(sys_ioperm)
{
   PRINT("sys_ioperm ( %d, %d, %d )", ARG1, ARG2, ARG3 );
   PRE_REG_READ3(long, "ioperm",
                 unsigned long, from, unsigned long, num, int, turn_on);
}

PRE(sys_syslog)
{
   *flags |= SfMayBlock;
   PRINT("sys_syslog (%d, %p, %d)", ARG1,ARG2,ARG3);
   PRE_REG_READ3(long, "syslog", int, type, char *, bufp, int, len);
   switch (ARG1) {
   // The kernel uses magic numbers here, rather than named constants,
   // therefore so do we.
   case 2: case 3: case 4:
      PRE_MEM_WRITE( "syslog(bufp)", ARG2, ARG3);
      break;
   default: 
      break;
   }
}
POST(sys_syslog)
{
   switch (ARG1) {
   case 2: case 3: case 4:
      POST_MEM_WRITE( ARG2, ARG3 );
      break;
   default:
      break;
   }
}

PRE(sys_vhangup)
{
   PRINT("sys_vhangup ( )");
   PRE_REG_READ0(long, "vhangup");
}

PRE(sys_sysinfo)
{
   PRINT("sys_sysinfo ( %p )",ARG1);
   PRE_REG_READ1(long, "sysinfo", struct sysinfo *, info);
   PRE_MEM_WRITE( "sysinfo(info)", ARG1, sizeof(struct vki_sysinfo) );
}
POST(sys_sysinfo)
{
   POST_MEM_WRITE( ARG1, sizeof(struct vki_sysinfo) );
}

PRE(sys_personality)
{
   PRINT("sys_personality ( %llu )", (ULong)ARG1);
   PRE_REG_READ1(long, "personality", vki_u_long, persona);
}

PRE(sys_sysctl)
{
   struct __vki_sysctl_args *args;
   PRINT("sys_sysctl ( %p )", ARG1 );
   args = (struct __vki_sysctl_args *)ARG1;
   PRE_REG_READ1(long, "sysctl", struct __sysctl_args *, args);
   PRE_MEM_WRITE( "sysctl(args)", ARG1, sizeof(struct __vki_sysctl_args) );
   if (!VG_(is_addressable)(ARG1, sizeof(struct __vki_sysctl_args), VKI_PROT_READ)) {
      SET_STATUS_Failure( VKI_EFAULT );
      return;
   }

   PRE_MEM_READ("sysctl(name)", (Addr)args->name, args->nlen * sizeof(*args->name));
   if (args->newval != NULL)
      PRE_MEM_READ("sysctl(newval)", (Addr)args->newval, args->newlen);
   if (args->oldlenp != NULL) {
      PRE_MEM_READ("sysctl(oldlenp)", (Addr)args->oldlenp, sizeof(*args->oldlenp));
      PRE_MEM_WRITE("sysctl(oldval)", (Addr)args->oldval, *args->oldlenp);
   }
}
POST(sys_sysctl)
{
   struct __vki_sysctl_args *args;
   args = (struct __vki_sysctl_args *)ARG1;
   if (args->oldlenp != NULL) {
      POST_MEM_WRITE((Addr)args->oldlenp, sizeof(*args->oldlenp));
      POST_MEM_WRITE((Addr)args->oldval, 1 + *args->oldlenp);
   }
}

PRE(sys_prctl)
{
   *flags |= SfMayBlock;
   PRINT( "prctl ( %d, %d, %d, %d, %d )", ARG1, ARG2, ARG3, ARG4, ARG5 );
   // XXX: too simplistic, often not all args are used
   // Nb: can't use "ARG2".."ARG5" here because that's our own macro...
   PRE_REG_READ5(long, "prctl",
                 int, option, unsigned long, arg2, unsigned long, arg3,
                 unsigned long, arg4, unsigned long, arg5);
   // XXX: totally wrong... we need to look at the 'option' arg, and do
   // PRE_MEM_READs/PRE_MEM_WRITEs as necessary...
}

PRE(sys_sendfile)
{
   *flags |= SfMayBlock;
   PRINT("sys_sendfile ( %d, %d, %p, %lu )", ARG1,ARG2,ARG3,ARG4);
   PRE_REG_READ4(ssize_t, "sendfile",
                 int, out_fd, int, in_fd, vki_off_t *, offset,
                 vki_size_t, count);
   if (ARG3 != 0)
      PRE_MEM_WRITE( "sendfile(offset)", ARG3, sizeof(vki_off_t) );
}
POST(sys_sendfile)
{
   if (ARG3 != 0 ) {
      POST_MEM_WRITE( ARG3, sizeof( vki_off_t ) );
   }
}

PRE(sys_sendfile64)
{
   *flags |= SfMayBlock;
   PRINT("sendfile64 ( %d, %d, %p, %lu )",ARG1,ARG2,ARG3,ARG4);
   PRE_REG_READ4(ssize_t, "sendfile64",
                 int, out_fd, int, in_fd, vki_loff_t *, offset,
                 vki_size_t, count);
   if (ARG3 != 0)
      PRE_MEM_WRITE( "sendfile64(offset)", ARG3, sizeof(vki_loff_t) );
}
POST(sys_sendfile64)
{
   if (ARG3 != 0 ) {
      POST_MEM_WRITE( ARG3, sizeof(vki_loff_t) );
   }
}

PRE(sys_futex)
{
   /* 
      arg    param                              used by ops

      ARG1 - u32 *futex				all
      ARG2 - int op
      ARG3 - int val				WAIT,WAKE,FD,REQUEUE,CMP_REQUEUE
      ARG4 - struct timespec *utime		WAIT:time*	REQUEUE,CMP_REQUEUE:val2
      ARG5 - u32 *uaddr2			REQUEUE,CMP_REQUEUE
      ARG6 - int val3				CMP_REQUEUE
    */
   PRINT("sys_futex ( %p, %d, %d, %p, %p )", ARG1,ARG2,ARG3,ARG4,ARG5);
   PRE_REG_READ6(long, "futex", 
                 vki_u32 *, futex, int, op, int, val,
                 struct timespec *, utime, vki_u32 *, uaddr2, int, val3);

   PRE_MEM_READ( "futex(futex)", ARG1, sizeof(Int) );

   *flags |= SfMayBlock;

   switch(ARG2) {
   case VKI_FUTEX_WAIT:
      if (ARG4 != 0)
	 PRE_MEM_READ( "futex(timeout)", ARG4, sizeof(struct vki_timespec) );
      break;

   case VKI_FUTEX_REQUEUE:
   case VKI_FUTEX_CMP_REQUEUE:
      PRE_MEM_READ( "futex(futex2)", ARG5, sizeof(Int) );
      break;

   case VKI_FUTEX_WAKE:
   case VKI_FUTEX_FD:
      /* no additional pointers */
      break;

   default:
      SET_STATUS_Failure( VKI_ENOSYS );   // some futex function we don't understand
      break;
   }
}
POST(sys_futex)
{
   vg_assert(SUCCESS);
   POST_MEM_WRITE( ARG1, sizeof(int) );
   if (ARG2 == VKI_FUTEX_FD) {
      if (!ML_(fd_allowed)(RES, "futex", tid, True)) {
         VG_(close)(RES);
         SET_STATUS_Failure( VKI_EMFILE );
      } else {
         if (VG_(clo_track_fds))
            ML_(record_fd_open_nameless)(tid, RES);
      }
   }
}

PRE(sys_mmap2)
{
   // Exactly like old_mmap() in x86-linux except:
   //  - all 6 args are passed in regs, rather than in a memory-block.
   //  - the file offset is specified in pagesize units rather than bytes,
   //    so that it can be used for files bigger than 2^32 bytes.
   PRINT("sys_mmap2 ( %p, %llu, %d, %d, %d, %d )",
         ARG1, (ULong)ARG2, ARG3, ARG4, ARG5, ARG6 );
   PRE_REG_READ6(long, "mmap2",
                 unsigned long, start, unsigned long, length,
                 unsigned long, prot,  unsigned long, flags,
                 unsigned long, fd,    unsigned long, offset);

   if (ARG2 == 0) {
      /* SuSV3 says: If len is zero, mmap() shall fail and no mapping
         shall be established. */
      SET_STATUS_Failure( VKI_EINVAL );
      return;
   }

   if (/*(ARG4 & VKI_MAP_FIXED) && */ (0 != (ARG1 & (VKI_PAGE_SIZE-1)))) {
      /* zap any misaligned addresses. */
      /* SuSV3 says misaligned addresses only cause the MAP_FIXED case
         to fail.   Here, we catch them all. */
      SET_STATUS_Failure( VKI_EINVAL );
      return;
   }

   if (ARG4 & VKI_MAP_FIXED) {
      if (!ML_(valid_client_addr)(ARG1, ARG2, tid, "mmap2"))
	 SET_STATUS_Failure( VKI_ENOMEM );
   } else {
      Addr a = VG_(find_map_space)(ARG1, ARG2, True);
      if (a == 0 && ARG1 != 0)
         a = VG_(find_map_space)(0, ARG2, True);
      if (a == 0) {
	 SET_STATUS_Failure( VKI_ENOMEM );
      } else {
         ARG1 = a;
         ARG4 |= VKI_MAP_FIXED;
      }
   }
}
POST(sys_mmap2)
{
   vg_assert(SUCCESS);
   vg_assert(ML_(valid_client_addr)(RES, ARG2, tid, "mmap2"));
   ML_(mmap_segment)( (Addr)RES, ARG2, ARG3, ARG4, ARG5,
                      ARG6 * (ULong)VKI_PAGE_SIZE );
}

/* ---------------------------------------------------------------------
   epoll_* wrappers
   ------------------------------------------------------------------ */

PRE(sys_epoll_create)
{
   PRINT("sys_epoll_create ( %d )", ARG1);
   PRE_REG_READ1(long, "epoll_create", int, size);
}
POST(sys_epoll_create)
{
   vg_assert(SUCCESS);
   if (!ML_(fd_allowed)(RES, "epoll_create", tid, True)) {
      VG_(close)(RES);
      SET_STATUS_Failure( VKI_EMFILE );
   } else {
      if (VG_(clo_track_fds))
         ML_(record_fd_open_nameless) (tid, RES);
   }
}

PRE(sys_epoll_ctl)
{
   static const HChar* epoll_ctl_s[3] = {
      "EPOLL_CTL_ADD",
      "EPOLL_CTL_DEL",
      "EPOLL_CTL_MOD"
   };
   PRINT("sys_epoll_ctl ( %d, %s, %d, %p )", 
         ARG1, ( ARG2<3 ? epoll_ctl_s[ARG2] : "?" ), ARG3, ARG4);
   PRE_REG_READ4(long, "epoll_ctl",
                 int, epfd, int, op, int, fd, struct vki_epoll_event *, event);
   if (ARG2 != VKI_EPOLL_CTL_DEL)
      PRE_MEM_READ( "epoll_ctl(event)", ARG4, sizeof(struct vki_epoll_event) );
}

PRE(sys_epoll_wait)
{
   *flags |= SfMayBlock;
   PRINT("sys_epoll_wait ( %d, %p, %d, %d )", ARG1, ARG2, ARG3, ARG4);
   PRE_REG_READ4(long, "epoll_wait",
                 int, epfd, struct vki_epoll_event *, events,
                 int, maxevents, int, timeout);
   PRE_MEM_WRITE( "epoll_wait(events)", ARG2, sizeof(struct vki_epoll_event)*ARG3);
}
POST(sys_epoll_wait)
{
   vg_assert(SUCCESS);
   if (RES > 0)
      POST_MEM_WRITE( ARG2, sizeof(struct vki_epoll_event)*RES ) ;
}

/* ---------------------------------------------------------------------
   tid-related wrappers
   ------------------------------------------------------------------ */

PRE(sys_gettid)
{
   PRINT("sys_gettid ()");
   PRE_REG_READ0(long, "gettid");
}

PRE(sys_set_tid_address)
{
   PRINT("sys_set_tid_address ( %p )", ARG1);
   PRE_REG_READ1(long, "set_tid_address", int *, tidptr);
}

//zz PRE(sys_tkill, Special)
//zz {
//zz    /* int tkill(pid_t tid, int sig); */
//zz    PRINT("sys_tkill ( %d, %d )", ARG1,ARG2);
//zz    PRE_REG_READ2(long, "tkill", int, tid, int, sig);
//zz    if (!ML_(client_signal_OK)(ARG2)) {
//zz       SET_STATUS_( -VKI_EINVAL );
//zz       return;
//zz    }
//zz 
//zz    /* If we're sending SIGKILL, check to see if the target is one of
//zz       our threads and handle it specially. */
//zz    if (ARG2 == VKI_SIGKILL && ML_(do_sigkill)(ARG1, -1))
//zz       SET_STATUS_(0);
//zz    else
//zz       SET_STATUS_(VG_(do_syscall2)(SYSNO, ARG1, ARG2));
//zz 
//zz    if (VG_(clo_trace_signals))
//zz       VG_(message)(Vg_DebugMsg, "tkill: sent signal %d to pid %d",
//zz 		   ARG2, ARG1);
//zz    // Check to see if this kill gave us a pending signal
//zz    XXX FIXME VG_(poll_signals)(tid);
//zz }

PRE(sys_tgkill)
{
   PRINT("sys_tgkill ( %d, %d, %d )", ARG1,ARG2,ARG3);
   PRE_REG_READ3(long, "tgkill", int, tgid, int, tid, int, sig);
   if (!ML_(client_signal_OK)(ARG3)) {
      SET_STATUS_Failure( VKI_EINVAL );
      return;
   }
   
   /* If we're sending SIGKILL, check to see if the target is one of
      our threads and handle it specially. */
   if (ARG3 == VKI_SIGKILL && ML_(do_sigkill)(ARG2, ARG1))
      SET_STATUS_Success(0);
   else
      SET_STATUS_from_SysRes(VG_(do_syscall3)(SYSNO, ARG1, ARG2, ARG3));

   if (VG_(clo_trace_signals))
      VG_(message)(Vg_DebugMsg, "tgkill: sent signal %d to pid %d/%d",
		   ARG3, ARG1, ARG2);
   /* Check to see if this kill gave us a pending signal */
   *flags |= SfPollAfter;
}
POST(sys_tgkill)
{
   if (VG_(clo_trace_signals))
      VG_(message)(Vg_DebugMsg, "tgkill: sent signal %d to pid %d/%d",
                   ARG3, ARG1, ARG2);
}

/* ---------------------------------------------------------------------
   fadvise64* wrappers
   ------------------------------------------------------------------ */

PRE(sys_fadvise64)
{
   PRINT("sys_fadvise64 ( %d, %lld, %lu, %d )",
         ARG1, LOHI64(ARG2,ARG3), ARG4, ARG5);
   PRE_REG_READ5(long, "fadvise64",
                 int, fd, vki_u32, offset_low, vki_u32, offset_high,
                 vki_size_t, len, int, advice);
}

PRE(sys_fadvise64_64)
{
   PRINT("sys_fadvise64_64 ( %d, %lld, %lld, %d )",
         ARG1, LOHI64(ARG2,ARG3), LOHI64(ARG4,ARG5), ARG6);
   PRE_REG_READ6(long, "fadvise64_64",
                 int, fd, vki_u32, offset_low, vki_u32, offset_high,
                 vki_u32, len_low, vki_u32, len_high, int, advice);
}

/* ---------------------------------------------------------------------
   io_* wrappers
   ------------------------------------------------------------------ */

// Nb: this wrapper has to pad/unpad memory around the syscall itself,
// and this allows us to control exactly the code that gets run while
// the padding is in place.
PRE(sys_io_setup)
{
   SizeT size;
   Addr addr;

   PRINT("sys_io_setup ( %u, %p )", ARG1,ARG2);
   PRE_REG_READ2(long, "io_setup",
                 unsigned, nr_events, vki_aio_context_t *, ctxp);
   PRE_MEM_WRITE( "io_setup(ctxp)", ARG2, sizeof(vki_aio_context_t) );
   
   size = VG_PGROUNDUP(sizeof(struct vki_aio_ring) +
                       ARG1*sizeof(struct vki_io_event));
   addr = VG_(find_map_space)(0, size, True);
   
   if (addr == 0) {
      SET_STATUS_Failure( VKI_ENOMEM );
      return;
   }

   VG_(map_segment)(addr, size, VKI_PROT_READ|VKI_PROT_WRITE, 0);
   
   VG_(pad_address_space)(0);
   SET_STATUS_from_SysRes( VG_(do_syscall2)(SYSNO, ARG1, ARG2) );
   VG_(unpad_address_space)(0);

   if (SUCCESS && RES == 0) {
      struct vki_aio_ring *r = *(struct vki_aio_ring **)ARG2;
        
      vg_assert(addr == (Addr)r);
      vg_assert(ML_(valid_client_addr)(addr, size, tid, "io_setup"));
                
      VG_TRACK( new_mem_mmap, addr, size, True, True, False );
      POST_MEM_WRITE( ARG2, sizeof(vki_aio_context_t) );
   }
   else {
      VG_(unmap_range)(addr, size);
   }
}

// Nb: This wrapper is "Special" because we need 'size' to do the unmap
// after the syscall.  We must get 'size' from the aio_ring structure,
// before the syscall, while the aio_ring structure still exists.  (And we
// know that we must look at the aio_ring structure because Tom inspected the
// kernel and glibc sources to see what they do, yuk.)
//
// XXX This segment can be implicitly unmapped when aio
// file-descriptors are closed...
PRE(sys_io_destroy)
{     
   Segment *s = VG_(find_segment)(ARG1);
   struct vki_aio_ring *r;
   SizeT size;
      
   PRINT("sys_io_destroy ( %llu )", (ULong)ARG1);
   PRE_REG_READ1(long, "io_destroy", vki_aio_context_t, ctx);

   // If we are going to seg fault (due to a bogus ARG1) do it as late as
   // possible...
   r = *(struct vki_aio_ring **)ARG1;
   size = VG_PGROUNDUP(sizeof(struct vki_aio_ring) + 
                       r->nr*sizeof(struct vki_io_event));

   SET_STATUS_from_SysRes( VG_(do_syscall1)(SYSNO, ARG1) );

   if (SUCCESS && RES == 0 && s != NULL) { 
      VG_TRACK( die_mem_munmap, ARG1, size );
      VG_(unmap_range)(ARG1, size);
   }  
}  

PRE(sys_io_getevents)
{
   *flags |= SfMayBlock;
   PRINT("sys_io_getevents ( %llu, %lld, %lld, %p, %p )",
         (ULong)ARG1,(Long)ARG2,(Long)ARG3,ARG4,ARG5);
   PRE_REG_READ5(long, "io_getevents",
                 vki_aio_context_t, ctx_id, long, min_nr, long, nr,
                 struct io_event *, events,
                 struct timespec *, timeout);
   if (ARG3 > 0)
      PRE_MEM_WRITE( "io_getevents(events)",
                     ARG4, sizeof(struct vki_io_event)*ARG3 );
   if (ARG5 != 0)
      PRE_MEM_READ( "io_getevents(timeout)",
                    ARG5, sizeof(struct vki_timespec));
}
POST(sys_io_getevents)
{
   Int i;
   vg_assert(SUCCESS);
   if (RES > 0) {
      POST_MEM_WRITE( ARG4, sizeof(struct vki_io_event)*RES );
      for (i = 0; i < RES; i++) {
         const struct vki_io_event *vev = ((struct vki_io_event *)ARG4) + i;
         const struct vki_iocb *cb = (struct vki_iocb *)(Addr)vev->obj;

         switch (cb->aio_lio_opcode) {
         case VKI_IOCB_CMD_PREAD:
            if (vev->result > 0)
               POST_MEM_WRITE( cb->aio_buf, vev->result );
            break;
            
         case VKI_IOCB_CMD_PWRITE:
            break;
           
         default:
            VG_(message)(Vg_DebugMsg,
                        "Warning: unhandled io_getevents opcode: %u\n",
                        cb->aio_lio_opcode);
            break;
         }
      }
   }
}

PRE(sys_io_submit)
{
   Int i;

   PRINT("sys_io_submit ( %llu, %ld, %p )", (ULong)ARG1,ARG2,ARG3);
   PRE_REG_READ3(long, "io_submit",
                 vki_aio_context_t, ctx_id, long, nr,
                 struct iocb **, iocbpp);
   PRE_MEM_READ( "io_submit(iocbpp)", ARG3, ARG2*sizeof(struct vki_iocb *) );
   if (ARG3 != 0) {
      for (i = 0; i < ARG2; i++) {
         struct vki_iocb *cb = ((struct vki_iocb **)ARG3)[i];
         PRE_MEM_READ( "io_submit(iocb)", (Addr)cb, sizeof(struct vki_iocb) );
         switch (cb->aio_lio_opcode) {
         case VKI_IOCB_CMD_PREAD:
            PRE_MEM_WRITE( "io_submit(PREAD)", cb->aio_buf, cb->aio_nbytes );
            break;

         case VKI_IOCB_CMD_PWRITE:
            PRE_MEM_READ( "io_submit(PWRITE)", cb->aio_buf, cb->aio_nbytes );
            break;
           
         default:
            VG_(message)(Vg_DebugMsg,"Warning: unhandled io_submit opcode: %u\n",
                         cb->aio_lio_opcode);
            break;
         }
      }
   }
}

PRE(sys_io_cancel)
{
   PRINT("sys_io_cancel ( %llu, %p, %p )", (ULong)ARG1,ARG2,ARG3);
   PRE_REG_READ3(long, "io_cancel",
                 vki_aio_context_t, ctx_id, struct iocb *, iocb,
                 struct io_event *, result);
   PRE_MEM_READ( "io_cancel(iocb)", ARG2, sizeof(struct vki_iocb) );
   PRE_MEM_WRITE( "io_cancel(result)", ARG3, sizeof(struct vki_io_event) );
}
POST(sys_io_cancel)
{
   POST_MEM_WRITE( ARG3, sizeof(struct vki_io_event) );
}

/* ---------------------------------------------------------------------
   *_mempolicy wrappers
   ------------------------------------------------------------------ */

PRE(sys_set_mempolicy)
{
   PRINT("sys_set_mempolicy ( %d, %p, %d )", ARG1,ARG2,ARG3);
   PRE_REG_READ3(long, "set_mempolicy",
                 int, policy, unsigned long *, nodemask,
                 unsigned long, maxnode);
   PRE_MEM_READ( "set_mempolicy(nodemask)", ARG2,
                 VG_ROUNDUP( ARG3, sizeof(UWord) ) / sizeof(UWord) );
}

PRE(sys_get_mempolicy)
{
   PRINT("sys_get_mempolicy ( %p, %p, %d, %p, %x )", ARG1,ARG2,ARG3,ARG4,ARG5);
   PRE_REG_READ5(long, "get_mempolicy",
                 int *, policy, unsigned long *, nodemask,
                 unsigned long, maxnode, unsigned long, addr,
                 unsigned long, flags);
   if (ARG1 != 0)
      PRE_MEM_WRITE( "get_mempolicy(policy)", ARG1, sizeof(Int) );
   if (ARG2 != 0)
      PRE_MEM_WRITE( "get_mempolicy(nodemask)", ARG2,
                     VG_ROUNDUP( ARG3, sizeof(UWord) * 8 ) / sizeof(UWord) );
}
POST(sys_get_mempolicy)
{
   if (ARG1 != 0)
      POST_MEM_WRITE( ARG1, sizeof(Int) );
   if (ARG2 != 0)
      POST_MEM_WRITE( ARG2, VG_ROUNDUP( ARG3, sizeof(UWord) * 8 ) / sizeof(UWord) );
}

/* ---------------------------------------------------------------------
   inotify_* wrappers
   ------------------------------------------------------------------ */

PRE(sys_inotify_init)
{
   PRINT("sys_inotify_init ( )");
   PRE_REG_READ0(long, "inotify_init");
}
POST(sys_inotify_init)
{
   vg_assert(SUCCESS);
   if (!ML_(fd_allowed)(RES, "inotify_init", tid, True)) {
      VG_(close)(RES);
      SET_STATUS_Failure( VKI_EMFILE );
   } else {
      if (VG_(clo_track_fds))
         ML_(record_fd_open_nameless) (tid, RES);
   }
}

PRE(sys_inotify_add_watch)
{
   PRINT( "sys_inotify_add_watch ( %d, %p, %x )", ARG1,ARG2,ARG3);
   PRE_REG_READ3(long, "inotify_add_watch", int, fd, char *, path, int, mask);
   PRE_MEM_RASCIIZ( "inotify_add_watch(path)", ARG2 );
}

PRE(sys_inotify_rm_watch)
{
   PRINT( "sys_inotify_rm_watch ( %d, %x )", ARG1,ARG2);
   PRE_REG_READ2(long, "inotify_rm_watch", int, fd, int, wd);
}

/* ---------------------------------------------------------------------
   mq_* wrappers
   ------------------------------------------------------------------ */

PRE(sys_mq_open)
{
   PRINT("sys_mq_open( %p(%s), %d, %lld, %p )",
         ARG1,ARG1,ARG2,(ULong)ARG3,ARG4);
   PRE_REG_READ4(long, "mq_open",
                 const char *, name, int, oflag, vki_mode_t, mode,
                 struct mq_attr *, attr);
   PRE_MEM_RASCIIZ( "mq_open(name)", ARG1 );
   if ((ARG2 & VKI_O_CREAT) != 0 && ARG4 != 0) {
      const struct vki_mq_attr *attr = (struct vki_mq_attr *)ARG4;
      PRE_MEM_READ( "mq_open(attr->mq_maxmsg)",
                     (Addr)&attr->mq_maxmsg, sizeof(attr->mq_maxmsg) );
      PRE_MEM_READ( "mq_open(attr->mq_msgsize)",
                     (Addr)&attr->mq_msgsize, sizeof(attr->mq_msgsize) );
   }
}
POST(sys_mq_open)
{
   vg_assert(SUCCESS);
   if (!ML_(fd_allowed)(RES, "mq_open", tid, True)) {
      VG_(close)(RES);
      SET_STATUS_Failure( VKI_EMFILE );
   } else {
      if (VG_(clo_track_fds))
         ML_(record_fd_open_with_given_name)(tid, RES, (Char*)ARG1);
   }
}

PRE(sys_mq_unlink)
{
   PRINT("sys_mq_unlink ( %p(%s) )", ARG1,ARG1);
   PRE_REG_READ1(long, "mq_unlink", const char *, name);
   PRE_MEM_RASCIIZ( "mq_unlink(name)", ARG1 );
}

PRE(sys_mq_timedsend)
{
   *flags |= SfMayBlock;
   PRINT("sys_mq_timedsend ( %d, %p, %llu, %d, %p )",
         ARG1,ARG2,(ULong)ARG3,ARG4,ARG5);
   PRE_REG_READ5(long, "mq_timedsend",
                 vki_mqd_t, mqdes, const char *, msg_ptr, vki_size_t, msg_len,
                 unsigned int, msg_prio, const struct timespec *, abs_timeout);
   if (!ML_(fd_allowed)(ARG1, "mq_timedsend", tid, False)) {
      SET_STATUS_Failure( VKI_EBADF );
   } else {
      PRE_MEM_READ( "mq_timedsend(msg_ptr)", ARG2, ARG3 );
      if (ARG5 != 0)
         PRE_MEM_READ( "mq_timedsend(abs_timeout)", ARG5,
                        sizeof(struct vki_timespec) );
   }
}

PRE(sys_mq_timedreceive)
{
   *flags |= SfMayBlock;
   PRINT("sys_mq_timedreceive( %d, %p, %llu, %p, %p )",
         ARG1,ARG2,(ULong)ARG3,ARG4,ARG5);
   PRE_REG_READ5(ssize_t, "mq_timedreceive",
                 vki_mqd_t, mqdes, char *, msg_ptr, vki_size_t, msg_len,
                 unsigned int *, msg_prio,
                 const struct timespec *, abs_timeout);
   if (!ML_(fd_allowed)(ARG1, "mq_timedreceive", tid, False)) {
      SET_STATUS_Failure( VKI_EBADF );
   } else {
      PRE_MEM_WRITE( "mq_timedreceive(msg_ptr)", ARG2, ARG3 );
      if (ARG4 != 0)
         PRE_MEM_WRITE( "mq_timedreceive(msg_prio)",
                        ARG4, sizeof(unsigned int) );
      if (ARG5 != 0)
         PRE_MEM_READ( "mq_timedreceive(abs_timeout)",
                        ARG5, sizeof(struct vki_timespec) );
   }
}
POST(sys_mq_timedreceive)
{
   POST_MEM_WRITE( ARG2, ARG3 );
   if (ARG4 != 0)
      POST_MEM_WRITE( ARG4, sizeof(unsigned int) );
}

PRE(sys_mq_notify)
{
   PRINT("sys_mq_notify( %d, %p )", ARG1,ARG2 );
   PRE_REG_READ2(long, "mq_notify",
                 vki_mqd_t, mqdes, const struct sigevent *, notification);
   if (!ML_(fd_allowed)(ARG1, "mq_notify", tid, False))
      SET_STATUS_Failure( VKI_EBADF );
   else if (ARG2 != 0)
      PRE_MEM_READ( "mq_notify(notification)",
                    ARG2, sizeof(struct vki_sigevent) );
}

PRE(sys_mq_getsetattr)
{
   PRINT("sys_mq_getsetattr( %d, %p, %p )", ARG1,ARG2,ARG3 );
   PRE_REG_READ3(long, "mq_getsetattr",
                 vki_mqd_t, mqdes, const struct mq_attr *, mqstat,
                 struct mq_attr *, omqstat);
   if (!ML_(fd_allowed)(ARG1, "mq_getsetattr", tid, False)) {
      SET_STATUS_Failure( VKI_EBADF );
   } else {
      if (ARG2 != 0) {
         const struct vki_mq_attr *attr = (struct vki_mq_attr *)ARG2;
         PRE_MEM_READ( "mq_getsetattr(mqstat->mq_flags)",
                        (Addr)&attr->mq_flags, sizeof(attr->mq_flags) );
      }
      if (ARG3 != 0)
         PRE_MEM_WRITE( "mq_getsetattr(omqstat)", ARG3,
                        sizeof(struct vki_mq_attr) );
   }   
}
POST(sys_mq_getsetattr)
{
   if (ARG3 != 0)
      POST_MEM_WRITE( ARG3, sizeof(struct vki_mq_attr) );
}

/* ---------------------------------------------------------------------
   clock_* wrappers
   ------------------------------------------------------------------ */

PRE(sys_clock_settime)
{
   PRINT("sys_clock_settime( %d, %p )", ARG1,ARG2);
   PRE_REG_READ2(long, "clock_settime", 
                 vki_clockid_t, clk_id, const struct timespec *, tp);
   PRE_MEM_READ( "clock_settime(tp)", ARG2, sizeof(struct vki_timespec) );
}

PRE(sys_clock_gettime)
{
   PRINT("sys_clock_gettime( %d, %p )" , ARG1,ARG2);
   PRE_REG_READ2(long, "clock_gettime", 
                 vki_clockid_t, clk_id, struct timespec *, tp);
   PRE_MEM_WRITE( "clock_gettime(tp)", ARG2, sizeof(struct vki_timespec) );
}
POST(sys_clock_gettime)
{
   POST_MEM_WRITE( ARG2, sizeof(struct vki_timespec) );
}

PRE(sys_clock_getres)
{
   PRINT("sys_clock_getres( %d, %p )" , ARG1,ARG2);
   // Nb: we can't use "RES" as the param name because that's a macro
   // defined above!
   PRE_REG_READ2(long, "clock_getres", 
                 vki_clockid_t, clk_id, struct timespec *, res);
   if (ARG2 != 0)
      PRE_MEM_WRITE( "clock_getres(res)", ARG2, sizeof(struct vki_timespec) );
}
POST(sys_clock_getres)
{
   if (ARG2 != 0)
      POST_MEM_WRITE( ARG2, sizeof(struct vki_timespec) );
}

PRE(sys_clock_nanosleep)
{
   *flags |= SfMayBlock|SfPostOnFail;
   PRINT("sys_clock_nanosleep( %d, %d, %p, %p )", ARG1,ARG2,ARG3,ARG4);
   PRE_REG_READ4(int32_t, "clock_nanosleep",
                 vki_clockid_t, clkid, int, flags,
                 const struct timespec *, rqtp, struct timespec *, rmtp);
   PRE_MEM_READ( "clock_nanosleep(rqtp)", ARG3, sizeof(struct vki_timespec) );
   if (ARG4 != 0)
      PRE_MEM_WRITE( "clock_nanosleep(rmtp)", ARG4, sizeof(struct vki_timespec) );
}
POST(sys_clock_nanosleep)
{
   if (ARG4 != 0 && FAILURE && RES_unchecked == VKI_EINTR)
      POST_MEM_WRITE( ARG4, sizeof(struct vki_timespec) );
}

/* ---------------------------------------------------------------------
   timer_* wrappers
   ------------------------------------------------------------------ */

PRE(sys_timer_create)
{
   PRINT("sys_timer_create( %d, %p, %p )", ARG1,ARG2,ARG3);
   PRE_REG_READ3(long, "timer_create",
                 vki_clockid_t, clockid, struct sigevent *, evp,
                 vki_timer_t *, timerid);
   if (ARG2 != 0)
      PRE_MEM_READ( "timer_create(evp)", ARG2, sizeof(struct vki_sigevent) );
   PRE_MEM_WRITE( "timer_create(timerid)", ARG3, sizeof(vki_timer_t) );
}
POST(sys_timer_create)
{
   POST_MEM_WRITE( ARG3, sizeof(vki_timer_t) );
}

PRE(sys_timer_settime)
{
   PRINT("sys_timer_settime( %lld, %d, %p, %p )", (ULong)ARG1,ARG2,ARG3,ARG4);
   PRE_REG_READ4(long, "timer_settime", 
                 vki_timer_t, timerid, int, flags,
                 const struct itimerspec *, value,
                 struct itimerspec *, ovalue);
   PRE_MEM_READ( "timer_settime(value)", ARG3,
                  sizeof(struct vki_itimerspec) );
   if (ARG4 != 0)
       PRE_MEM_WRITE( "timer_settime(ovalue)", ARG4,
                      sizeof(struct vki_itimerspec) );
}
POST(sys_timer_settime)
{
   if (ARG4 != 0)
      POST_MEM_WRITE( ARG4, sizeof(struct vki_itimerspec) );
}

PRE(sys_timer_gettime)
{
   PRINT("sys_timer_gettime( %lld, %p )", (ULong)ARG1,ARG2);
   PRE_REG_READ2(long, "timer_gettime", 
                 vki_timer_t, timerid, struct itimerspec *, value);
   PRE_MEM_WRITE( "timer_gettime(value)", ARG2,
                  sizeof(struct vki_itimerspec));
}
POST(sys_timer_gettime)
{
   POST_MEM_WRITE( ARG2, sizeof(struct vki_itimerspec) );
}

PRE(sys_timer_getoverrun)
{
   PRINT("sys_timer_getoverrun( %p )", ARG1);
   PRE_REG_READ1(long, "timer_getoverrun", vki_timer_t, timerid);
}

PRE(sys_timer_delete)
{
   PRINT("sys_timer_delete( %p )", ARG1);
   PRE_REG_READ1(long, "timer_delete", vki_timer_t, timerid);
}

/* ---------------------------------------------------------------------
   capabilities wrappers
   ------------------------------------------------------------------ */

PRE(sys_capget)
{
   PRINT("sys_capget ( %p, %p )", ARG1, ARG2 );
   PRE_REG_READ2(long, "capget", 
                 vki_cap_user_header_t, header, vki_cap_user_data_t, data);
   PRE_MEM_READ( "capget(header)", ARG1, 
                  sizeof(struct __vki_user_cap_header_struct) );
   PRE_MEM_WRITE( "capget(data)", ARG2, 
                  sizeof(struct __vki_user_cap_data_struct) );
}
POST(sys_capget)
{
   if (ARG2 != (Addr)NULL)
      POST_MEM_WRITE( ARG2, sizeof(struct __vki_user_cap_data_struct) );
}

PRE(sys_capset)
{
   PRINT("sys_capset ( %p, %p )", ARG1, ARG2 );
   PRE_REG_READ2(long, "capset", 
                 vki_cap_user_header_t, header,
                 const vki_cap_user_data_t, data);
   PRE_MEM_READ( "capset(header)", 
                  ARG1, sizeof(struct __vki_user_cap_header_struct) );
   PRE_MEM_READ( "capset(data)", 
                  ARG2, sizeof(struct __vki_user_cap_data_struct) );
}

/* ---------------------------------------------------------------------
   16-bit uid/gid/groups wrappers
   ------------------------------------------------------------------ */

PRE(sys_getuid16)
{
   PRINT("sys_getuid16 ( )");
   PRE_REG_READ0(long, "getuid16");
}

PRE(sys_setuid16)
{
   PRINT("sys_setuid16 ( %d )", ARG1);
   PRE_REG_READ1(long, "setuid16", vki_old_uid_t, uid);
}

PRE(sys_getgid16)
{
   PRINT("sys_getgid16 ( )");
   PRE_REG_READ0(long, "getgid16");
}

PRE(sys_setgid16)
{
   PRINT("sys_setgid16 ( %d )", ARG1);
   PRE_REG_READ1(long, "setgid16", vki_old_gid_t, gid);
}

PRE(sys_geteuid16)
{
   PRINT("sys_geteuid16 ( )");
   PRE_REG_READ0(long, "geteuid16");
}

PRE(sys_getegid16)
{
   PRINT("sys_getegid16 ( )");
   PRE_REG_READ0(long, "getegid16");
}

PRE(sys_setreuid16)
{
   PRINT("setreuid16 ( 0x%x, 0x%x )", ARG1, ARG2);
   PRE_REG_READ2(long, "setreuid16", vki_old_uid_t, ruid, vki_old_uid_t, euid);
}

PRE(sys_setregid16)
{
   PRINT("sys_setregid16 ( %d, %d )", ARG1, ARG2);
   PRE_REG_READ2(long, "setregid16", vki_old_gid_t, rgid, vki_old_gid_t, egid);
}

PRE(sys_getgroups16)
{
   PRINT("sys_getgroups16 ( %d, %p )", ARG1, ARG2);
   PRE_REG_READ2(long, "getgroups16", int, size, vki_old_gid_t *, list);
   if (ARG1 > 0)
      PRE_MEM_WRITE( "getgroups16(list)", ARG2, ARG1 * sizeof(vki_old_gid_t) );
}
POST(sys_getgroups16)
{
   vg_assert(SUCCESS);
   if (ARG1 > 0 && RES > 0)
      POST_MEM_WRITE( ARG2, RES * sizeof(vki_old_gid_t) );
}

PRE(sys_setgroups16)
{
   PRINT("sys_setgroups16 ( %llu, %p )", (ULong)ARG1, ARG2);
   PRE_REG_READ2(long, "setgroups16", int, size, vki_old_gid_t *, list);
   if (ARG1 > 0)
      PRE_MEM_READ( "setgroups16(list)", ARG2, ARG1 * sizeof(vki_old_gid_t) );
}

/* ---------------------------------------------------------------------
   *chown16 wrappers
   ------------------------------------------------------------------ */

PRE(sys_chown16)
{
   PRINT("sys_chown16 ( %p, 0x%x, 0x%x )", ARG1,ARG2,ARG3);
   PRE_REG_READ3(long, "chown16",
                 const char *, path,
                 vki_old_uid_t, owner, vki_old_gid_t, group);
   PRE_MEM_RASCIIZ( "chown16(path)", ARG1 );
}

PRE(sys_fchown16)
{
   PRINT("sys_fchown16 ( %d, %d, %d )", ARG1,ARG2,ARG3);
   PRE_REG_READ3(long, "fchown16",
                 unsigned int, fd, vki_old_uid_t, owner, vki_old_gid_t, group);
}

/* ---------------------------------------------------------------------
   *xattr wrappers
   ------------------------------------------------------------------ */

PRE(sys_setxattr)
{
   *flags |= SfMayBlock;
   PRINT("sys_setxattr ( %p, %p, %p, %llu, %d )",
         ARG1, ARG2, ARG3, (ULong)ARG4, ARG5);
   PRE_REG_READ5(long, "setxattr",
                 char *, path, char *, name,
                 void *, value, vki_size_t, size, int, flags);
   PRE_MEM_RASCIIZ( "setxattr(path)", ARG1 );
   PRE_MEM_RASCIIZ( "setxattr(name)", ARG2 );
   PRE_MEM_READ( "setxattr(value)", ARG3, ARG4 );
}

PRE(sys_lsetxattr)
{
   *flags |= SfMayBlock;
   PRINT("sys_lsetxattr ( %p, %p, %p, %llu, %d )",
         ARG1, ARG2, ARG3, (ULong)ARG4, ARG5);
   PRE_REG_READ5(long, "lsetxattr",
                 char *, path, char *, name,
                 void *, value, vki_size_t, size, int, flags);
   PRE_MEM_RASCIIZ( "lsetxattr(path)", ARG1 );
   PRE_MEM_RASCIIZ( "lsetxattr(name)", ARG2 );
   PRE_MEM_READ( "lsetxattr(value)", ARG3, ARG4 );
}

PRE(sys_fsetxattr)
{
   *flags |= SfMayBlock;
   PRINT("sys_fsetxattr ( %d, %p, %p, %llu, %d )",
         ARG1, ARG2, ARG3, (ULong)ARG4, ARG5);
   PRE_REG_READ5(long, "fsetxattr",
                 int, fd, char *, name, void *, value,
                 vki_size_t, size, int, flags);
   PRE_MEM_RASCIIZ( "fsetxattr(name)", ARG2 );
   PRE_MEM_READ( "fsetxattr(value)", ARG3, ARG4 );
}

PRE(sys_getxattr)
{
   *flags |= SfMayBlock;
   PRINT("sys_getxattr ( %p, %p, %p, %llu )", ARG1,ARG2,ARG3, (ULong)ARG4);
   PRE_REG_READ4(ssize_t, "getxattr",
                 char *, path, char *, name, void *, value, vki_size_t, size);
   PRE_MEM_RASCIIZ( "getxattr(path)", ARG1 );
   PRE_MEM_RASCIIZ( "getxattr(name)", ARG2 );
   PRE_MEM_WRITE( "getxattr(value)", ARG3, ARG4 );
}
POST(sys_getxattr)
{
   vg_assert(SUCCESS);
   if (RES > 0 && ARG3 != (Addr)NULL) {
      POST_MEM_WRITE( ARG3, RES );
   }
}

PRE(sys_lgetxattr)
{
   *flags |= SfMayBlock;
   PRINT("sys_lgetxattr ( %p, %p, %p, %llu )", ARG1,ARG2,ARG3, (ULong)ARG4);
   PRE_REG_READ4(ssize_t, "lgetxattr",
                 char *, path, char *, name, void *, value, vki_size_t, size);
   PRE_MEM_RASCIIZ( "lgetxattr(path)", ARG1 );
   PRE_MEM_RASCIIZ( "lgetxattr(name)", ARG2 );
   PRE_MEM_WRITE( "lgetxattr(value)", ARG3, ARG4 );
}
POST(sys_lgetxattr)
{
   vg_assert(SUCCESS);
   if (RES > 0 && ARG3 != (Addr)NULL) {
      POST_MEM_WRITE( ARG3, RES );
   }
}

PRE(sys_fgetxattr)
{
   *flags |= SfMayBlock;
   PRINT("sys_fgetxattr ( %d, %p, %p, %llu )", ARG1, ARG2, ARG3, (ULong)ARG4);
   PRE_REG_READ4(ssize_t, "fgetxattr",
                 int, fd, char *, name, void *, value, vki_size_t, size);
   PRE_MEM_RASCIIZ( "fgetxattr(name)", ARG2 );
   PRE_MEM_WRITE( "fgetxattr(value)", ARG3, ARG4 );
}
POST(sys_fgetxattr)
{
   if (RES > 0 && ARG3 != (Addr)NULL)
      POST_MEM_WRITE( ARG3, RES );
}

PRE(sys_listxattr)
{
   *flags |= SfMayBlock;
   PRINT("sys_listxattr ( %p, %p, %llu )", ARG1, ARG2, (ULong)ARG3);
   PRE_REG_READ3(ssize_t, "listxattr",
                 char *, path, char *, list, vki_size_t, size);
   PRE_MEM_RASCIIZ( "listxattr(path)", ARG1 );
   PRE_MEM_WRITE( "listxattr(list)", ARG2, ARG3 );
}
POST(sys_listxattr)
{
   if (RES > 0 && ARG2 != (Addr)NULL)
      POST_MEM_WRITE( ARG2, RES );
}

PRE(sys_llistxattr)
{
   *flags |= SfMayBlock;
   PRINT("sys_llistxattr ( %p, %p, %llu )", ARG1, ARG2, (ULong)ARG3);
   PRE_REG_READ3(ssize_t, "llistxattr",
                 char *, path, char *, list, vki_size_t, size);
   PRE_MEM_RASCIIZ( "llistxattr(path)", ARG1 );
   PRE_MEM_WRITE( "llistxattr(list)", ARG2, ARG3 );
}
POST(sys_llistxattr)
{
   if (RES > 0 && ARG2 != (Addr)NULL)
      POST_MEM_WRITE( ARG2, RES );
}

PRE(sys_flistxattr)
{
   *flags |= SfMayBlock;
   PRINT("sys_flistxattr ( %d, %p, %llu )", ARG1, ARG2, (ULong)ARG3);
   PRE_REG_READ3(ssize_t, "flistxattr",
                 int, fd, char *, list, vki_size_t, size);
   PRE_MEM_WRITE( "flistxattr(list)", ARG2, ARG3 );
}
POST(sys_flistxattr)
{
   if (RES > 0 && ARG2 != (Addr)NULL)
      POST_MEM_WRITE( ARG2, RES );
}

PRE(sys_removexattr)
{
   *flags |= SfMayBlock;
   PRINT("sys_removexattr ( %p, %p )", ARG1, ARG2);
   PRE_REG_READ2(long, "removexattr", char *, path, char *, name);
   PRE_MEM_RASCIIZ( "removexattr(path)", ARG1 );
   PRE_MEM_RASCIIZ( "removexattr(name)", ARG2 );
}

PRE(sys_lremovexattr)
{
   *flags |= SfMayBlock;
   PRINT("sys_lremovexattr ( %p, %p )", ARG1, ARG2);
   PRE_REG_READ2(long, "lremovexattr", char *, path, char *, name);
   PRE_MEM_RASCIIZ( "lremovexattr(path)", ARG1 );
   PRE_MEM_RASCIIZ( "lremovexattr(name)", ARG2 );
}

PRE(sys_fremovexattr)
{
   *flags |= SfMayBlock;
   PRINT("sys_fremovexattr ( %d, %p )", ARG1, ARG2);
   PRE_REG_READ2(long, "fremovexattr", int, fd, char *, name);
   PRE_MEM_RASCIIZ( "fremovexattr(name)", ARG2 );
}

/* ---------------------------------------------------------------------
   sched_* wrappers
   ------------------------------------------------------------------ */

PRE(sys_sched_setparam)
{
   PRINT("sched_setparam ( %d, %p )", ARG1, ARG2 );
   PRE_REG_READ2(long, "sched_setparam", 
                 vki_pid_t, pid, struct sched_param *, p);
   PRE_MEM_READ( "sched_setparam(p)", ARG2, sizeof(struct vki_sched_param) );
}
POST(sys_sched_setparam)
{
   POST_MEM_WRITE( ARG2, sizeof(struct vki_sched_param) );
}

PRE(sys_sched_getparam)
{
   PRINT("sched_getparam ( %d, %p )", ARG1, ARG2 );
   PRE_REG_READ2(long, "sched_getparam", 
                 vki_pid_t, pid, struct sched_param *, p);
   PRE_MEM_WRITE( "sched_getparam(p)", ARG2, sizeof(struct vki_sched_param) );
}
POST(sys_sched_getparam)
{
   POST_MEM_WRITE( ARG2, sizeof(struct vki_sched_param) );
}

PRE(sys_sched_getscheduler)
{
   PRINT("sys_sched_getscheduler ( %d )", ARG1);
   PRE_REG_READ1(long, "sched_getscheduler", vki_pid_t, pid);
}

PRE(sys_sched_setscheduler)
{
   PRINT("sys_sched_setscheduler ( %d, %d, %p )", ARG1,ARG2,ARG3);
   PRE_REG_READ3(long, "sched_setscheduler", 
                 vki_pid_t, pid, int, policy, struct sched_param *, p);
   if (ARG3 != 0)
      PRE_MEM_READ( "sched_setscheduler(p)", 
		    ARG3, sizeof(struct vki_sched_param));
}

PRE(sys_sched_yield)
{
   *flags |= SfMayBlock;
   PRINT("sched_yield()");
   PRE_REG_READ0(long, "sys_sched_yield");
}

PRE(sys_sched_get_priority_max)
{
   PRINT("sched_get_priority_max ( %d )", ARG1);
   PRE_REG_READ1(long, "sched_get_priority_max", int, policy);
}

PRE(sys_sched_get_priority_min)
{
   PRINT("sched_get_priority_min ( %d )", ARG1);
   PRE_REG_READ1(long, "sched_get_priority_min", int, policy);
}

PRE(sys_sched_setaffinity)
{
   PRINT("sched_setaffinity ( %d, %d, %p )", ARG1, ARG2, ARG3);
   PRE_REG_READ3(long, "sched_setaffinity", 
                 vki_pid_t, pid, unsigned int, len, unsigned long *, mask);
   PRE_MEM_READ( "sched_setaffinity(mask)", ARG3, ARG2);
}

PRE(sys_sched_getaffinity)
{
   PRINT("sched_getaffinity ( %d, %d, %p )", ARG1, ARG2, ARG3);
   PRE_REG_READ3(long, "sched_getaffinity", 
                 vki_pid_t, pid, unsigned int, len, unsigned long *, mask);
   PRE_MEM_WRITE( "sched_getaffinity(mask)", ARG3, ARG2);
}
POST(sys_sched_getaffinity)
{
   POST_MEM_WRITE(ARG3, ARG2);
}

/* ---------------------------------------------------------------------
   miscellaneous wrappers
   ------------------------------------------------------------------ */

PRE(sys_munlockall)
{
   *flags |= SfMayBlock;
   PRINT("sys_munlockall ( )");
   PRE_REG_READ0(long, "munlockall");
}

// This has different signatures for different platforms.
//
//  x86:   int  sys_pipe(unsigned long __user *fildes);
//  AMD64: long sys_pipe(int *fildes);
//  ppc32: int  sys_pipe(int __user *fildes);
//  ppc64: int  sys_pipe(int __user *fildes);
//
// The type of the argument is most important, and it is an array of 32 bit
// values in all cases.  (The return type differs across platforms, but it
// is not used.)  So we use 'int' as its type.  This fixed bug #113230 which
// was caused by using an array of 'unsigned long's, which didn't work on
// AMD64.
PRE(sys_pipe)
{
   PRINT("sys_pipe ( %p )", ARG1);
   PRE_REG_READ1(int, "pipe", int *, filedes);
   PRE_MEM_WRITE( "pipe(filedes)", ARG1, 2*sizeof(int) );
}
POST(sys_pipe)
{
   Int *p = (Int *)ARG1;

   if (!ML_(fd_allowed)(p[0], "pipe", tid, True) ||
       !ML_(fd_allowed)(p[1], "pipe", tid, True)) {
      VG_(close)(p[0]);
      VG_(close)(p[1]);
      SET_STATUS_Failure( VKI_EMFILE );
   } else {
      POST_MEM_WRITE( ARG1, 2*sizeof(int) );
      if (VG_(clo_track_fds)) {
         ML_(record_fd_open_nameless)(tid, p[0]);
         ML_(record_fd_open_nameless)(tid, p[1]);
      }
   }
}

PRE(sys_quotactl)
{
   PRINT("sys_quotactl (0x%x, %p, 0x%x, 0x%x )", ARG1,ARG2,ARG3, ARG4);
   PRE_REG_READ4(long, "quotactl",
                 unsigned int, cmd, const char *, special, vki_qid_t, id,
                 void *, addr);
   PRE_MEM_RASCIIZ( "quotactl(special)", ARG2 );
}

PRE(sys_waitid)
{
   *flags |= SfMayBlock;
   PRINT("sys_waitid( %d, %d, %p, %d, %p )", ARG1,ARG2,ARG3,ARG4,ARG5);
   PRE_REG_READ5(int32_t, "sys_waitid",
                 int, which, vki_pid_t, pid, struct vki_siginfo *, infop,
                 int, options, struct vki_rusage *, ru);
   PRE_MEM_WRITE( "waitid(infop)", ARG3, sizeof(struct vki_siginfo) );
   if (ARG5 != 0)
      PRE_MEM_WRITE( "waitid(ru)", ARG5, sizeof(struct vki_rusage) );
}
POST(sys_waitid)
{
   POST_MEM_WRITE( ARG3, sizeof(struct vki_siginfo) );
   if (ARG5 != 0)
      POST_MEM_WRITE( ARG5, sizeof(struct vki_rusage) );
}

/* ---------------------------------------------------------------------
   utime wrapper
   ------------------------------------------------------------------ */

PRE(sys_utime)
{
   *flags |= SfMayBlock;
   PRINT("sys_utime ( %p, %p )", ARG1,ARG2);
   PRE_REG_READ2(long, "utime", char *, filename, struct utimbuf *, buf);
   PRE_MEM_RASCIIZ( "utime(filename)", ARG1 );
   if (ARG2 != 0)
      PRE_MEM_READ( "utime(buf)", ARG2, sizeof(struct vki_utimbuf) );
}

/* ---------------------------------------------------------------------
   lseek wrapper
   ------------------------------------------------------------------ */

PRE(sys_lseek)
{
   PRINT("sys_lseek ( %d, %d, %d )", ARG1,ARG2,ARG3);
   PRE_REG_READ3(vki_off_t, "lseek",
                 unsigned int, fd, vki_off_t, offset, unsigned int, whence);
}

/* ---------------------------------------------------------------------
   sig* wrappers
   ------------------------------------------------------------------ */

PRE(sys_sigpending)
{
   PRINT( "sys_sigpending ( %p )", ARG1 );
   PRE_REG_READ1(long, "sigpending", vki_old_sigset_t *, set);
   PRE_MEM_WRITE( "sigpending(set)", ARG1, sizeof(vki_old_sigset_t));
}
POST(sys_sigpending)
{
   POST_MEM_WRITE( ARG1, sizeof(vki_old_sigset_t) ) ;
}

// This syscall is not used on amd64/Linux -- it only provides
// sys_rt_sigprocmask, which uses sigset_t rather than old_sigset_t.
// This wrapper is only suitable for 32-bit architectures.
// (XXX: so how is it that PRE(sys_sigpending) above doesn't need
// conditional compilation like this?)
#if defined(VGP_x86_linux) || defined(VGP_ppc32_linux)
PRE(sys_sigprocmask)
{
   vki_old_sigset_t* set;
   vki_old_sigset_t* oldset;
   vki_sigset_t bigger_set;
   vki_sigset_t bigger_oldset;

   PRINT("sys_sigprocmask ( %d, %p, %p )",ARG1,ARG2,ARG3);
   PRE_REG_READ3(long, "sigprocmask", 
                 int, how, vki_old_sigset_t *, set, vki_old_sigset_t *, oldset);
   if (ARG2 != 0)
      PRE_MEM_READ( "sigprocmask(set)", ARG2, sizeof(vki_old_sigset_t));
   if (ARG3 != 0)
      PRE_MEM_WRITE( "sigprocmask(oldset)", ARG3, sizeof(vki_old_sigset_t));

   // Nb: We must convert the smaller vki_old_sigset_t params into bigger
   // vki_sigset_t params.
   set    = (vki_old_sigset_t*)ARG2;
   oldset = (vki_old_sigset_t*)ARG3;

   VG_(memset)(&bigger_set,    0, sizeof(vki_sigset_t));
   VG_(memset)(&bigger_oldset, 0, sizeof(vki_sigset_t));
   if (set)
      bigger_set.sig[0] = *(vki_old_sigset_t*)set;

   SET_STATUS_from_SysRes(
      VG_(do_sys_sigprocmask) ( tid, ARG1 /*how*/, 
                                set ? &bigger_set    : NULL,
                             oldset ? &bigger_oldset : NULL)
   );

   if (oldset)
      *oldset = bigger_oldset.sig[0];

   if (SUCCESS)
      *flags |= SfPollAfter;
}
POST(sys_sigprocmask)
{
   vg_assert(SUCCESS);
   if (RES == 0 && ARG3 != 0)
      POST_MEM_WRITE( ARG3, sizeof(vki_old_sigset_t));
}
#endif

/* ---------------------------------------------------------------------
   rt_sig* wrappers
   ------------------------------------------------------------------ */

PRE(sys_rt_sigaction)
{
   PRINT("sys_rt_sigaction ( %d, %p, %p, %d )", ARG1,ARG2,ARG3,ARG4);
   PRE_REG_READ4(long, "rt_sigaction",
                 int, signum, const struct sigaction *, act,
                 struct sigaction *, oldact, vki_size_t, sigsetsize);

   if (ARG2 != 0) {
      struct vki_sigaction *sa = (struct vki_sigaction *)ARG2;
      PRE_MEM_READ( "rt_sigaction(act->sa_handler)", (Addr)&sa->ksa_handler, sizeof(sa->ksa_handler));
      PRE_MEM_READ( "rt_sigaction(act->sa_mask)", (Addr)&sa->sa_mask, sizeof(sa->sa_mask));
      PRE_MEM_READ( "rt_sigaction(act->sa_flags)", (Addr)&sa->sa_flags, sizeof(sa->sa_flags));
      if (sa->sa_flags & VKI_SA_RESTORER)
         PRE_MEM_READ( "rt_sigaction(act->sa_restorer)", (Addr)&sa->sa_restorer, sizeof(sa->sa_restorer));
   }
   if (ARG3 != 0)
      PRE_MEM_WRITE( "rt_sigaction(oldact)", ARG3, sizeof(struct vki_sigaction));

   // XXX: doesn't seem right to be calling do_sys_sigaction for
   // sys_rt_sigaction... perhaps this function should be renamed
   // VG_(do_sys_rt_sigaction)()  --njn

   SET_STATUS_from_SysRes(
      VG_(do_sys_sigaction)(ARG1, (const struct vki_sigaction *)ARG2,
                            (struct vki_sigaction *)ARG3)
   );
}
POST(sys_rt_sigaction)
{
   vg_assert(SUCCESS);
   if (RES == 0 && ARG3 != 0)
      POST_MEM_WRITE( ARG3, sizeof(struct vki_sigaction));
}

PRE(sys_rt_sigprocmask)
{
   PRINT("sys_rt_sigprocmask ( %d, %p, %p, %llu )",ARG1,ARG2,ARG3,(ULong)ARG4);
   PRE_REG_READ4(long, "rt_sigprocmask", 
                 int, how, vki_sigset_t *, set, vki_sigset_t *, oldset,
                 vki_size_t, sigsetsize);
   if (ARG2 != 0)
      PRE_MEM_READ( "rt_sigprocmask(set)", ARG2, sizeof(vki_sigset_t));
   if (ARG3 != 0)
      PRE_MEM_WRITE( "rt_sigprocmask(oldset)", ARG3, sizeof(vki_sigset_t));

   // Like the kernel, we fail if the sigsetsize is not exactly what we expect.
   if (sizeof(vki_sigset_t) != ARG4)
      SET_STATUS_Failure( VKI_EMFILE );
   else {
      SET_STATUS_from_SysRes( 
                  VG_(do_sys_sigprocmask) ( tid, ARG1 /*how*/, 
                                            (vki_sigset_t*) ARG2,
                                            (vki_sigset_t*) ARG3 )
      );
   }

   if (SUCCESS)
      *flags |= SfPollAfter;
}
POST(sys_rt_sigprocmask)
{
   vg_assert(SUCCESS);
   if (RES == 0 && ARG3 != 0)
      POST_MEM_WRITE( ARG3, sizeof(vki_sigset_t));
}

PRE(sys_rt_sigpending)
{
   PRINT( "sys_rt_sigpending ( %p )", ARG1 );
   PRE_REG_READ2(long, "rt_sigpending", 
                 vki_sigset_t *, set, vki_size_t, sigsetsize);
   PRE_MEM_WRITE( "rt_sigpending(set)", ARG1, sizeof(vki_sigset_t));
}
POST(sys_rt_sigpending)
{
   POST_MEM_WRITE( ARG1, sizeof(vki_sigset_t) ) ;
}

PRE(sys_rt_sigtimedwait)
{
   *flags |= SfMayBlock;
   PRINT("sys_rt_sigtimedwait ( %p, %p, %p, %lld )",
         ARG1,ARG2,ARG3,(ULong)ARG4);
   PRE_REG_READ4(long, "rt_sigtimedwait", 
                 const vki_sigset_t *, set, vki_siginfo_t *, info,
                 const struct timespec *, timeout, vki_size_t, sigsetsize);
   if (ARG1 != 0) 
      PRE_MEM_READ(  "rt_sigtimedwait(set)",  ARG1, sizeof(vki_sigset_t));
   if (ARG2 != 0)
      PRE_MEM_WRITE( "rt_sigtimedwait(info)", ARG2, sizeof(vki_siginfo_t) );
   if (ARG3 != 0)
      PRE_MEM_READ( "rt_sigtimedwait(timeout)",
                    ARG3, sizeof(struct vki_timespec) );
}
POST(sys_rt_sigtimedwait)
{
   if (ARG2 != 0)
      POST_MEM_WRITE( ARG2, sizeof(vki_siginfo_t) );
}

PRE(sys_rt_sigqueueinfo)
{
   PRINT("sys_rt_sigqueueinfo(%d, %d, %p)", ARG1, ARG2, ARG3);
   PRE_REG_READ3(long, "rt_sigqueueinfo", 
                 int, pid, int, sig, vki_siginfo_t *, uinfo);
   if (ARG2 != 0)
      PRE_MEM_READ( "rt_sigqueueinfo(uinfo)", ARG3, sizeof(vki_siginfo_t) );
}
POST(sys_rt_sigqueueinfo)
{
   if (!ML_(client_signal_OK)(ARG2))
      SET_STATUS_Failure( VKI_EINVAL );
}

// XXX: x86-specific?  The kernel prototypes for the different archs are
//      hard to decipher.
PRE(sys_rt_sigsuspend)
{
   /* The C library interface to sigsuspend just takes a pointer to
      a signal mask but this system call has two arguments - a pointer
      to the mask and the number of bytes used by it. The kernel insists
      on the size being equal to sizeof(sigset_t) however and will just
      return EINVAL if it isn't.
    */
   *flags |= SfMayBlock;
   PRINT("sys_rt_sigsuspend ( %p, %d )", ARG1,ARG2 );
   PRE_REG_READ2(int, "rt_sigsuspend", vki_sigset_t *, mask, vki_size_t, size)
   if (ARG1 != (Addr)NULL) {
      PRE_MEM_READ( "rt_sigsuspend(mask)", ARG1, sizeof(vki_sigset_t) );
   }
}

/* ---------------------------------------------------------------------
   linux msg* wrapper helpers
   ------------------------------------------------------------------ */

void
ML_(linux_PRE_sys_msgsnd) ( ThreadId tid,
                            UWord arg0, UWord arg1, UWord arg2, UWord arg3 )
{
   /* int msgsnd(int msqid, struct msgbuf *msgp, size_t msgsz, int msgflg); */
   struct vki_msgbuf *msgp = (struct vki_msgbuf *)arg1;
   PRE_MEM_READ( "msgsnd(msgp->mtype)", (Addr)&msgp->mtype, sizeof(msgp->mtype) );
   PRE_MEM_READ( "msgsnd(msgp->mtext)", (Addr)&msgp->mtext, arg2 );
}

void
ML_(linux_PRE_sys_msgrcv) ( ThreadId tid,
                            UWord arg0, UWord arg1, UWord arg2,
                            UWord arg3, UWord arg4 )
{
   /* ssize_t msgrcv(int msqid, struct msgbuf *msgp, size_t msgsz,
                     long msgtyp, int msgflg); */
   struct vki_msgbuf *msgp = (struct vki_msgbuf *)arg1;
   PRE_MEM_WRITE( "msgrcv(msgp->mtype)", (Addr)&msgp->mtype, sizeof(msgp->mtype) );
   PRE_MEM_WRITE( "msgrcv(msgp->mtext)", (Addr)&msgp->mtext, arg2 );
}
void
ML_(linux_POST_sys_msgrcv) ( ThreadId tid,
                             UWord res,
                             UWord arg0, UWord arg1, UWord arg2,
                             UWord arg3, UWord arg4 )
{
   struct vki_msgbuf *msgp = (struct vki_msgbuf *)arg1;
   POST_MEM_WRITE( (Addr)&msgp->mtype, sizeof(msgp->mtype) );
   POST_MEM_WRITE( (Addr)&msgp->mtext, res );
}

void
ML_(linux_PRE_sys_msgctl) ( ThreadId tid,
                            UWord arg0, UWord arg1, UWord arg2 )
{
   /* int msgctl(int msqid, int cmd, struct msqid_ds *buf); */
   switch (arg1 /* cmd */) {
   case VKI_IPC_INFO:
   case VKI_MSG_INFO:
   case VKI_IPC_INFO|VKI_IPC_64:
   case VKI_MSG_INFO|VKI_IPC_64:
      PRE_MEM_WRITE( "msgctl(IPC_INFO, buf)",
                     arg2, sizeof(struct vki_msginfo) );
      break;
   case VKI_IPC_STAT:
   case VKI_MSG_STAT:
      PRE_MEM_WRITE( "msgctl(IPC_STAT, buf)",
                     arg2, sizeof(struct vki_msqid_ds) );
      break;
   case VKI_IPC_STAT|VKI_IPC_64:
   case VKI_MSG_STAT|VKI_IPC_64:
      PRE_MEM_WRITE( "msgctl(IPC_STAT, arg.buf)",
                     arg2, sizeof(struct vki_msqid64_ds) );
      break;
   case VKI_IPC_SET:
      PRE_MEM_READ( "msgctl(IPC_SET, arg.buf)",
                    arg2, sizeof(struct vki_msqid_ds) );
      break;
   case VKI_IPC_SET|VKI_IPC_64:
      PRE_MEM_READ( "msgctl(IPC_SET, arg.buf)",
                    arg2, sizeof(struct vki_msqid64_ds) );
      break;
   }
}
void
ML_(linux_POST_sys_msgctl) ( ThreadId tid,
                             UWord res,
                             UWord arg0, UWord arg1, UWord arg2 )
{
   switch (arg1 /* cmd */) {
   case VKI_IPC_INFO:
   case VKI_MSG_INFO:
   case VKI_IPC_INFO|VKI_IPC_64:
   case VKI_MSG_INFO|VKI_IPC_64:
      POST_MEM_WRITE( arg2, sizeof(struct vki_msginfo) );
      break;
   case VKI_IPC_STAT:
   case VKI_MSG_STAT:
      POST_MEM_WRITE( arg2, sizeof(struct vki_msqid_ds) );
      break;
   case VKI_IPC_STAT|VKI_IPC_64:
   case VKI_MSG_STAT|VKI_IPC_64:
      POST_MEM_WRITE( arg2, sizeof(struct vki_msqid64_ds) );
      break;
   }
}

#undef PRE
#undef POST

/*--------------------------------------------------------------------*/
/*--- end                                                          ---*/
/*--------------------------------------------------------------------*/