From: Tomas Hruby <tom@minix3.org>
Date: Wed, 3 Feb 2010 09:04:48 +0000 (+0000)
Subject: This patch removes the global variables who_p and who_e from the
X-Git-Tag: v3.1.7~325
X-Git-Url: http://zhaoyanbai.com/repos/%22http:/www.isc.org/icons/invmod.png?a=commitdiff_plain;h=cca24d06d876ac2230a5ee578c444cf92a8b5bd5;p=minix.git

This patch removes the global variables who_p and who_e from the
kernel (sys task).  The main reason is that these would have to become
cpu local variables on SMP.  Once the system task is not a task but a
genuine part of the kernel there is even less reason to have these
extra variables as proc_ptr will already contain all neccessary
information. In addition converting who_e to the process pointer and
back again all the time will be avoided.

Although proc_ptr will contain all important information, accessing it
as a cpu local variable will be fairly expensive, hence the value
would be assigned to some on stack local variable. Therefore it is
better to add the 'caller' argument to the syscall handlers to pass
the value on stack anyway. It also clearly denotes on who's behalf is
the syscall being executed.

This patch also ANSIfies the syscall function headers.

Last but not least, it also fixes a potential bug in virtual_copy_f()
in case the check is disabled. So far the function in case of a
failure could possible reuse an old who_p in case this function had
not been called from the system task.

virtual_copy_f() takes the caller as a parameter too. In case the
checking is disabled, the caller must be NULL and non NULL if it is
enabled as we must be able to suspend the caller.
---

diff --git a/kernel/arch/i386/do_int86.c b/kernel/arch/i386/do_int86.c
index 6b7510e1a..5a646acc7 100644
--- a/kernel/arch/i386/do_int86.c
+++ b/kernel/arch/i386/do_int86.c
@@ -18,17 +18,16 @@ struct reg86u reg86;
 /*===========================================================================*
  *				do_int86					     *
  *===========================================================================*/
-PUBLIC int do_int86(m_ptr)
-register message *m_ptr;	/* pointer to request message */
+PUBLIC int do_int86(struct proc * caller, message * m_ptr)
 {
-  data_copy(who_e, (vir_bytes) m_ptr->INT86_REG86,
+  data_copy(caller->p_endpoint, (vir_bytes) m_ptr->INT86_REG86,
 	SYSTEM, (vir_bytes) &reg86, sizeof(reg86));
 
   level0(int86);
 
   /* Copy results back to the caller */
   data_copy(SYSTEM, (vir_bytes) &reg86,
-	who_e, (vir_bytes) m_ptr->INT86_REG86, sizeof(reg86));
+	caller->p_endpoint, (vir_bytes) m_ptr->INT86_REG86, sizeof(reg86));
 
   /* The BIOS call eats interrupts. Call get_randomness to generate some
    * entropy. Normally, get_randomness is called from an interrupt handler.
diff --git a/kernel/arch/i386/do_iopenable.c b/kernel/arch/i386/do_iopenable.c
index 552b3a5f3..fdc762e5a 100644
--- a/kernel/arch/i386/do_iopenable.c
+++ b/kernel/arch/i386/do_iopenable.c
@@ -10,20 +10,20 @@
 
 #include "../../system.h"
 #include "../../kernel.h"
+#include <minix/endpoint.h>
 
 #include "proto.h"
 
 /*===========================================================================*
  *			        do_iopenable				     *
  *===========================================================================*/
-PUBLIC int do_iopenable(m_ptr)
-register message *m_ptr;	/* pointer to request message */
+PUBLIC int do_iopenable(struct proc * caller, message * m_ptr)
 {
   int proc_nr;
 
 #if 1 /* ENABLE_USERPRIV && ENABLE_USERIOPL */
   if (m_ptr->IO_ENDPT == SELF) {
-	proc_nr = who_p;
+	proc_nr = _ENDPOINT_P(caller->p_endpoint);
   } else if(!isokendpt(m_ptr->IO_ENDPT, &proc_nr))
 	return(EINVAL);
   enable_iop(proc_addr(proc_nr));
diff --git a/kernel/arch/i386/do_readbios.c b/kernel/arch/i386/do_readbios.c
index d5a5a068c..0250326ab 100644
--- a/kernel/arch/i386/do_readbios.c
+++ b/kernel/arch/i386/do_readbios.c
@@ -13,8 +13,7 @@
 /*===========================================================================*
  *				do_readbios				     *
  *===========================================================================*/
-PUBLIC int do_readbios(m_ptr)
-register message *m_ptr;	/* pointer to request message */
+PUBLIC int do_readbios(struct proc * caller, message * m_ptr)
 {
   struct vir_addr src, dst;     
         
@@ -25,5 +24,5 @@ register message *m_ptr;	/* pointer to request message */
   src.proc_nr_e = NONE;
   dst.proc_nr_e = m_ptr->m_source;      
 
-  return virtual_copy_vmcheck(&src, &dst, m_ptr->RDB_SIZE);
+  return virtual_copy_vmcheck(caller, &src, &dst, m_ptr->RDB_SIZE);
 }
diff --git a/kernel/arch/i386/do_sdevio.c b/kernel/arch/i386/do_sdevio.c
index 0e7641e90..95770037b 100644
--- a/kernel/arch/i386/do_sdevio.c
+++ b/kernel/arch/i386/do_sdevio.c
@@ -21,9 +21,7 @@
 /*===========================================================================*
  *			        do_sdevio                                    *
  *===========================================================================*/
-PUBLIC int do_sdevio(
-  register message *m_ptr	/* pointer to request message */
-)
+PUBLIC int do_sdevio(struct proc * caller, message *m_ptr)
 {
   vir_bytes newoffset;
   endpoint_t newep;
@@ -32,7 +30,6 @@ PUBLIC int do_sdevio(
   long port = m_ptr->DIO_PORT;
   phys_bytes phys_buf;
   int i, req_type, req_dir, size, nr_io_range;
-  struct proc *rp;
   struct priv *privp;
   struct io_range *iorp;
   struct proc *destproc;
@@ -55,7 +52,7 @@ PUBLIC int do_sdevio(
    * that initiated the device I/O. Kernel processes, of course, are denied.
    */
   if (proc_nr_e == SELF)
-	proc_nr = who_p;
+	proc_nr = _ENDPOINT_P(caller->p_endpoint);
   else
 	if(!isokendpt(proc_nr_e, &proc_nr))
 		return(EINVAL);
@@ -68,7 +65,7 @@ PUBLIC int do_sdevio(
   /* Check for 'safe' variants. */
   if((m_ptr->DIO_REQUEST & _DIO_SAFEMASK) == _DIO_SAFE) {
      /* Map grant address to physical address. */
-     if(verify_grant(proc_nr_e, who_e, 
+     if(verify_grant(proc_nr_e, caller->p_endpoint,
 	(vir_bytes) m_ptr->DIO_VEC_ADDR,
 	count,
 	req_dir == _DIO_INPUT ? CPF_WRITE : CPF_READ,
@@ -86,10 +83,10 @@ PUBLIC int do_sdevio(
          return(EFAULT);
      }
   } else {
-     if(proc_nr != who_p)
+     if(proc_nr != _ENDPOINT_P(caller->p_endpoint))
      {
 	kprintf("do_sdevio: unsafe sdevio by %d in %d denied\n",
-		who_e, proc_nr_e);
+		caller->p_endpoint, proc_nr_e);
 	return EPERM;
      }
      /* Get and check physical address. */
@@ -110,8 +107,7 @@ PUBLIC int do_sdevio(
 	default: size= 4; break;	/* Be conservative */
   }
 
-  rp= proc_addr(who_p);
-  privp= priv(rp);
+  privp= priv(caller);
   if (privp && privp->s_flags & CHECK_IO_PORT)
   {
 	port= m_ptr->DIO_PORT;
diff --git a/kernel/arch/i386/memory.c b/kernel/arch/i386/memory.c
index b784e59a1..6062f2ce3 100644
--- a/kernel/arch/i386/memory.c
+++ b/kernel/arch/i386/memory.c
@@ -775,7 +775,8 @@ int vm_phys_memset(phys_bytes ph, u8_t c, phys_bytes bytes)
 /*===========================================================================*
  *				virtual_copy_f				     *
  *===========================================================================*/
-PUBLIC int virtual_copy_f(src_addr, dst_addr, bytes, vmcheck)
+PUBLIC int virtual_copy_f(caller, src_addr, dst_addr, bytes, vmcheck)
+struct proc * caller;
 struct vir_addr *src_addr;	/* source virtual address */
 struct vir_addr *dst_addr;	/* destination virtual address */
 vir_bytes bytes;		/* # of bytes to copy  */
@@ -791,6 +792,8 @@ int vmcheck;			/* if nonzero, can return VMSUSPEND */
   struct proc *procs[2];
   NOREC_ENTER(virtualcopy);
 
+  vmassert((vmcheck && caller) || (!vmcheck && !caller));
+
   /* Check copy count. */
   if (bytes <= 0) return(EDOM);
 
@@ -823,8 +826,8 @@ int vmcheck;			/* if nonzero, can return VMSUSPEND */
 	          phys_addr[i] = umap_local(p, seg_index, vir_addr[i]->offset,
 			bytes);
 	  else
-	  	phys_addr[i] = umap_virtual(p, seg_index, vir_addr[i]->offset,
-			bytes);
+	  	phys_addr[i] = umap_virtual(p, seg_index,
+				vir_addr[i]->offset, bytes);
 	  if(phys_addr[i] == 0) {
 		kprintf("virtual_copy: map 0x%x failed for %s seg %d, "
 			"offset %lx, len %d, i %d\n",
@@ -861,11 +864,8 @@ int vmcheck;			/* if nonzero, can return VMSUSPEND */
 
   if(vm_running) {
 	int r;
-	struct proc *caller;
-
-	caller = proc_addr(who_p);
 
-	if(RTS_ISSET(caller, RTS_VMREQUEST)) {
+	if(caller && RTS_ISSET(caller, RTS_VMREQUEST)) {
 		vmassert(caller->p_vmrequest.vmresult != VMSUSPEND);
 		RTS_LOCK_UNSET(caller, RTS_VMREQUEST);
 		if(caller->p_vmrequest.vmresult != OK) {
@@ -884,7 +884,7 @@ int vmcheck;			/* if nonzero, can return VMSUSPEND */
 		phys_bytes lin;
 		if(r != EFAULT_SRC && r != EFAULT_DST)
 			minix_panic("lin_lin_copy failed", r);
-		if(!vmcheck) {
+		if(!vmcheck || !caller) {
 	  		NOREC_RETURN(virtualcopy, r);
 		}
 
@@ -909,9 +909,9 @@ int vmcheck;			/* if nonzero, can return VMSUSPEND */
 #endif
 
 		vmassert(proc_ptr->p_endpoint == SYSTEM);
-		vm_suspend(caller, target, lin, bytes, wr, VMSTYPE_KERNELCALL);
-
-	  	NOREC_RETURN(virtualcopy, VMSUSPEND);
+		vm_suspend(caller, target, lin, bytes, wr,
+				VMSTYPE_KERNELCALL);
+		NOREC_RETURN(virtualcopy, VMSUSPEND);
 	}
 
   	NOREC_RETURN(virtualcopy, OK);
@@ -941,8 +941,7 @@ int vmcheck;			/* if nonzero, can return VMSUSPEND */
 /*===========================================================================*
  *				data_copy				     *
  *===========================================================================*/
-PUBLIC int data_copy(
-	endpoint_t from_proc, vir_bytes from_addr,
+PUBLIC int data_copy(endpoint_t from_proc, vir_bytes from_addr,
 	endpoint_t to_proc, vir_bytes to_addr,
 	size_t bytes)
 {
@@ -960,7 +959,7 @@ PUBLIC int data_copy(
 /*===========================================================================*
  *				data_copy_vmcheck			     *
  *===========================================================================*/
-PUBLIC int data_copy_vmcheck(
+PUBLIC int data_copy_vmcheck(struct proc * caller,
 	endpoint_t from_proc, vir_bytes from_addr,
 	endpoint_t to_proc, vir_bytes to_addr,
 	size_t bytes)
@@ -973,7 +972,7 @@ PUBLIC int data_copy_vmcheck(
   src.proc_nr_e = from_proc;
   dst.proc_nr_e = to_proc;
 
-  return virtual_copy_vmcheck(&src, &dst, bytes);
+  return virtual_copy_vmcheck(caller, &src, &dst, bytes);
 }
 
 /*===========================================================================*
diff --git a/kernel/glo.h b/kernel/glo.h
index b16bca3fd..a473aa65e 100644
--- a/kernel/glo.h
+++ b/kernel/glo.h
@@ -42,8 +42,6 @@ EXTERN u32_t system_hz;				/* HZ value */
 EXTERN reg_t mon_ss, mon_sp;		/* boot monitor stack */
 EXTERN int mon_return;			/* true if we can return to monitor */
 EXTERN int do_serial_debug;
-EXTERN endpoint_t who_e;		/* message source endpoint */
-EXTERN int who_p;			/* message source proc */
 EXTERN int sys_call_code;		/* kernel call number in SYSTEM */
 EXTERN time_t boottime;
 EXTERN char params_buffer[512];		/* boot monitor parameters */
diff --git a/kernel/proto.h b/kernel/proto.h
index 79cd21302..7a89feacf 100644
--- a/kernel/proto.h
+++ b/kernel/proto.h
@@ -61,13 +61,13 @@ _PROTOTYPE( void sig_delay_done, (struct proc *rp)			);
 _PROTOTYPE( void sys_task, (void)					);
 #define numap_local(proc_nr, vir_addr, bytes) \
 	umap_local(proc_addr(proc_nr), D, (vir_addr), (bytes))
-_PROTOTYPE( phys_bytes umap_grant, (struct proc *, cp_grant_id_t,
-	vir_bytes));
+_PROTOTYPE( phys_bytes umap_grant, (struct proc *, cp_grant_id_t, vir_bytes));
 _PROTOTYPE( void clear_endpoint, (struct proc *rc)			);
 _PROTOTYPE( phys_bytes umap_bios, (vir_bytes vir_addr, vir_bytes bytes));
 
 /* system/do_newmap.c */
-_PROTOTYPE( int newmap, (struct proc *rp, struct mem_map *map_ptr)	);
+_PROTOTYPE( int newmap, (struct proc * caller, struct proc *rp,
+					struct mem_map *map_ptr));
 
 /* system/do_vtimer.c */
 _PROTOTYPE( void vtimer_check, (struct proc *rp)			);
@@ -88,17 +88,18 @@ _PROTOTYPE( char *rtsflagstr, (int flags) );
 _PROTOTYPE( char *miscflagstr, (int flags) );
 
 /* system/do_safemap.c */
-_PROTOTYPE( int map_invoke_vm, (int req_type,
+_PROTOTYPE( int map_invoke_vm, (struct proc * caller, int req_type,
 		endpoint_t end_d, int seg_d, vir_bytes off_d,
 		endpoint_t end_s, int seg_s, vir_bytes off_s,
 		size_t size, int flag));
 
 /* system/do_safecopy.c */
-_PROTOTYPE( int verify_grant, (endpoint_t, endpoint_t, cp_grant_id_t, vir_bytes,
-	int, vir_bytes, vir_bytes *, endpoint_t *));
+_PROTOTYPE( int verify_grant, (endpoint_t, endpoint_t,
+	cp_grant_id_t, vir_bytes, int,
+	vir_bytes, vir_bytes *, endpoint_t *));
 
 /* system/do_sysctl.c */
-_PROTOTYPE( int do_sysctl, (message *m));
+_PROTOTYPE( int do_sysctl, (struct proc * caller, message *m));
 
 #if SPROFILE
 /* profile.c */
@@ -112,13 +113,17 @@ _PROTOTYPE( phys_bytes phys_copy, (phys_bytes source, phys_bytes dest,
                 phys_bytes count)                                       );
 _PROTOTYPE( void phys_copy_fault, (void));
 _PROTOTYPE( void phys_copy_fault_in_kernel, (void));
-#define virtual_copy(src, dst, bytes) virtual_copy_f(src, dst, bytes, 0)
-#define virtual_copy_vmcheck(src, dst, bytes) virtual_copy_f(src, dst, bytes, 1)
-_PROTOTYPE( int virtual_copy_f, (struct vir_addr *src, struct vir_addr *dst, 
-				vir_bytes bytes, int vmcheck)		);
+#define virtual_copy(src, dst, bytes) \
+				virtual_copy_f(NULL, src, dst, bytes, 0)
+#define virtual_copy_vmcheck(caller, src, dst, bytes) \
+				virtual_copy_f(caller, src, dst, bytes, 1)
+_PROTOTYPE( int virtual_copy_f, (struct proc * caller,
+			struct vir_addr *src, struct vir_addr *dst,
+			vir_bytes bytes, int vmcheck)		);
 _PROTOTYPE( int data_copy, (endpoint_t from, vir_bytes from_addr,
 	endpoint_t to, vir_bytes to_addr, size_t bytes));
-_PROTOTYPE( int data_copy_vmcheck, (endpoint_t from, vir_bytes from_addr,
+_PROTOTYPE( int data_copy_vmcheck, (struct proc *,
+	endpoint_t from, vir_bytes from_addr,
 	endpoint_t to, vir_bytes to_addr, size_t bytes));
 _PROTOTYPE( void alloc_segments, (struct proc *rp)                      );
 _PROTOTYPE( void vm_init, (struct proc *first)        			);
@@ -128,8 +133,8 @@ _PROTOTYPE( void cp_mess, (int src,phys_clicks src_clicks,
         vir_bytes src_offset, phys_clicks dst_clicks, vir_bytes dst_offset));
 _PROTOTYPE( phys_bytes umap_remote, (struct proc* rp, int seg,
         vir_bytes vir_addr, vir_bytes bytes)				);
-_PROTOTYPE( phys_bytes umap_virtual, (struct proc* rp, int seg,
-        vir_bytes vir_addr, vir_bytes bytes)				);
+_PROTOTYPE( phys_bytes umap_virtual, (struct proc* rp,
+			int seg, vir_bytes vir_addr, vir_bytes bytes)	);
 _PROTOTYPE( phys_bytes seg2phys, (U16_t)                                );
 _PROTOTYPE( int vm_phys_memset, (phys_bytes source, u8_t pattern,
                 phys_bytes count)                                       );
diff --git a/kernel/system.c b/kernel/system.c
index a64980cb2..4f064a192 100644
--- a/kernel/system.c
+++ b/kernel/system.c
@@ -50,7 +50,7 @@
  * because the dummy is declared extern. If an illegal call is given, the 
  * array size will be negative and this won't compile. 
  */
-PUBLIC int (*call_vec[NR_SYS_CALLS])(message *m_ptr);
+PUBLIC int (*call_vec[NR_SYS_CALLS])(struct proc * caller, message *m_ptr);
 char *callnames[NR_SYS_CALLS];
 
 #define map(call_nr, handler) \
@@ -72,6 +72,8 @@ PUBLIC void sys_task()
   register struct proc *caller_ptr;
   int s;
   int call_nr;
+  int who_p;
+  endpoint_t who_e;
 
   /* Initialize the system task. */
   initialize();
@@ -105,7 +107,8 @@ PUBLIC void sys_task()
 	  result = ECALLDENIED;			/* illegal message type */
       }
       else {
-          result = (*call_vec[call_nr])(&m); /* handle the system call */
+	  /* handle the system call */
+          result = (*call_vec[call_nr])(caller_ptr, &m);
       }
 
       if(result == VMSUSPEND) {
@@ -549,6 +552,7 @@ PRIVATE struct proc *vmrestart_check(message *m)
 {
 	int type;
 	struct proc *restarting;
+	int who_p;
 
       /* Anyone waiting to be vm-restarted? */
 
@@ -589,4 +593,5 @@ PRIVATE struct proc *vmrestart_check(message *m)
 	   		minix_panic("strange restart type", type);
 	}
 	minix_panic("fell out of switch", NO_NUM);
+	return NULL;
 }
diff --git a/kernel/system.h b/kernel/system.h
index 4e8489e70..00e7cd08a 100644
--- a/kernel/system.h
+++ b/kernel/system.h
@@ -36,161 +36,161 @@
 #include "proc.h"
 
 /* Default handler for unused kernel calls. */
-_PROTOTYPE( int do_unused, (message *m_ptr) );
+_PROTOTYPE( int do_unused, (struct proc * caller, message *m_ptr) );
 
-_PROTOTYPE( int do_exec, (message *m_ptr) );		
+_PROTOTYPE( int do_exec, (struct proc * caller, message *m_ptr) );
 #if ! USE_EXEC
 #define do_exec do_unused
 #endif
 
-_PROTOTYPE( int do_fork, (message *m_ptr) );
+_PROTOTYPE( int do_fork, (struct proc * caller, message *m_ptr) );
 #if ! USE_FORK
 #define do_fork do_unused
 #endif
 
-_PROTOTYPE( int do_newmap, (message *m_ptr) );
+_PROTOTYPE( int do_newmap, (struct proc * caller, message *m_ptr) );
 #if ! USE_NEWMAP
 #define do_newmap do_unused
 #endif
 
-_PROTOTYPE( int do_exit, (message *m_ptr) );
+_PROTOTYPE( int do_exit, (struct proc * caller, message *m_ptr) );
 #if ! USE_EXIT
 #define do_exit do_unused
 #endif
 
-_PROTOTYPE( int do_trace, (message *m_ptr) );	
+_PROTOTYPE( int do_trace, (struct proc * caller, message *m_ptr) );
 #if ! USE_TRACE
 #define do_trace do_unused
 #endif
 
-_PROTOTYPE( int do_nice, (message *m_ptr) );
+_PROTOTYPE( int do_nice, (struct proc * caller, message *m_ptr) );
 #if ! USE_NICE
 #define do_nice do_unused
 #endif
 
-_PROTOTYPE( int do_runctl, (message *m_ptr) );
+_PROTOTYPE( int do_runctl, (struct proc * caller, message *m_ptr) );
 #if ! USE_RUNCTL
 #define do_runctl do_unused
 #endif
 
-_PROTOTYPE( int do_copy, (message *m_ptr) );	
+_PROTOTYPE( int do_copy, (struct proc * caller, message *m_ptr) );
 #define do_vircopy 	do_copy
 #if ! (USE_VIRCOPY || USE_PHYSCOPY)
 #define do_copy do_unused
 #endif
 
-_PROTOTYPE( int do_umap, (message *m_ptr) );
+_PROTOTYPE( int do_umap, (struct proc * caller, message *m_ptr) );
 #if ! USE_UMAP
 #define do_umap do_unused
 #endif
 
-_PROTOTYPE( int do_memset, (message *m_ptr) );
+_PROTOTYPE( int do_memset, (struct proc * caller, message *m_ptr) );
 #if ! USE_MEMSET
 #define do_memset do_unused
 #endif
 
-_PROTOTYPE( int do_abort, (message *m_ptr) );
+_PROTOTYPE( int do_abort, (struct proc * caller, message *m_ptr) );
 #if ! USE_ABORT
 #define do_abort do_unused
 #endif
 
-_PROTOTYPE( int do_getinfo, (message *m_ptr) );
+_PROTOTYPE( int do_getinfo, (struct proc * caller, message *m_ptr) );
 #if ! USE_GETINFO
 #define do_getinfo do_unused
 #endif
 
-_PROTOTYPE( int do_privctl, (message *m_ptr) );	
+_PROTOTYPE( int do_privctl, (struct proc * caller, message *m_ptr) );
 #if ! USE_PRIVCTL
 #define do_privctl do_unused
 #endif
 
-_PROTOTYPE( int do_segctl, (message *m_ptr) );
+_PROTOTYPE( int do_segctl, (struct proc * caller, message *m_ptr) );
 #if ! USE_SEGCTL
 #define do_segctl do_unused
 #endif
 
-_PROTOTYPE( int do_irqctl, (message *m_ptr) );
+_PROTOTYPE( int do_irqctl, (struct proc * caller, message *m_ptr) );
 #if ! USE_IRQCTL
 #define do_irqctl do_unused
 #endif
 
-_PROTOTYPE( int do_devio, (message *m_ptr) );
+_PROTOTYPE( int do_devio, (struct proc * caller, message *m_ptr) );
 #if ! USE_DEVIO
 #define do_devio do_unused
 #endif
 
-_PROTOTYPE( int do_vdevio, (message *m_ptr) );
+_PROTOTYPE( int do_vdevio, (struct proc * caller, message *m_ptr) );
 #if ! USE_VDEVIO
 #define do_vdevio do_unused
 #endif
 
-_PROTOTYPE( int do_int86, (message *m_ptr) );
+_PROTOTYPE( int do_int86, (struct proc * caller, message *m_ptr) );
 
-_PROTOTYPE( int do_sdevio, (message *m_ptr) );
+_PROTOTYPE( int do_sdevio, (struct proc * caller, message *m_ptr) );
 #if ! USE_SDEVIO
 #define do_sdevio do_unused
 #endif
 
-_PROTOTYPE( int do_kill, (message *m_ptr) );
+_PROTOTYPE( int do_kill, (struct proc * caller, message *m_ptr) );
 #if ! USE_KILL
 #define do_kill do_unused
 #endif
 
-_PROTOTYPE( int do_getksig, (message *m_ptr) );
+_PROTOTYPE( int do_getksig, (struct proc * caller, message *m_ptr) );
 #if ! USE_GETKSIG
 #define do_getksig do_unused
 #endif
 
-_PROTOTYPE( int do_endksig, (message *m_ptr) );
+_PROTOTYPE( int do_endksig, (struct proc * caller, message *m_ptr) );
 #if ! USE_ENDKSIG
 #define do_endksig do_unused
 #endif
 
-_PROTOTYPE( int do_sigsend, (message *m_ptr) );
+_PROTOTYPE( int do_sigsend, (struct proc * caller, message *m_ptr) );
 #if ! USE_SIGSEND
 #define do_sigsend do_unused
 #endif
 
-_PROTOTYPE( int do_sigreturn, (message *m_ptr) );
+_PROTOTYPE( int do_sigreturn, (struct proc * caller, message *m_ptr) );
 #if ! USE_SIGRETURN
 #define do_sigreturn do_unused
 #endif
 
-_PROTOTYPE( int do_times, (message *m_ptr) );		
+_PROTOTYPE( int do_times, (struct proc * caller, message *m_ptr) );
 #if ! USE_TIMES
 #define do_times do_unused
 #endif
 
-_PROTOTYPE( int do_setalarm, (message *m_ptr) );	
+_PROTOTYPE( int do_setalarm, (struct proc * caller, message *m_ptr) );
 #if ! USE_SETALARM
 #define do_setalarm do_unused
 #endif
 
-_PROTOTYPE( int do_stime, (message *m_ptr) );	
+_PROTOTYPE( int do_stime, (struct proc * caller, message *m_ptr) );
 
-_PROTOTYPE( int do_vtimer, (message *m_ptr) );
+_PROTOTYPE( int do_vtimer, (struct proc * caller, message *m_ptr) );
 #if ! USE_VTIMER
 #define do_vtimer do_unused
 #endif
 
-_PROTOTYPE( int do_safecopy, (message *m_ptr) );	
-_PROTOTYPE( int do_vsafecopy, (message *m_ptr) );	
-_PROTOTYPE( int do_iopenable, (message *m_ptr) );	
-_PROTOTYPE( int do_vmctl, (message *m_ptr) );	
-_PROTOTYPE( int do_setgrant, (message *m_ptr) );	
-_PROTOTYPE( int do_readbios, (message *m_ptr) );	
+_PROTOTYPE( int do_safecopy, (struct proc * caller, message *m_ptr) );
+_PROTOTYPE( int do_vsafecopy, (struct proc * caller, message *m_ptr) );
+_PROTOTYPE( int do_iopenable, (struct proc * caller, message *m_ptr) );
+_PROTOTYPE( int do_vmctl, (struct proc * caller, message *m_ptr) );
+_PROTOTYPE( int do_setgrant, (struct proc * caller, message *m_ptr) );
+_PROTOTYPE( int do_readbios, (struct proc * caller, message *m_ptr) );
 
-_PROTOTYPE( int do_safemap, (message *m_ptr) );	
-_PROTOTYPE( int do_saferevmap, (message *m_ptr) );	
-_PROTOTYPE( int do_safeunmap, (message *m_ptr) );	
+_PROTOTYPE( int do_safemap, (struct proc * caller, message *m_ptr) );
+_PROTOTYPE( int do_saferevmap, (struct proc * caller, message *m_ptr) );
+_PROTOTYPE( int do_safeunmap, (struct proc * caller, message *m_ptr) );
 
-_PROTOTYPE( int do_sprofile, (message *m_ptr) );
+_PROTOTYPE( int do_sprofile, (struct proc * caller, message *m_ptr) );
 #if ! SPROFILE
 #define do_sprofile do_unused
 #endif
 
-_PROTOTYPE( int do_cprofile, (message *m_ptr) );
-_PROTOTYPE( int do_profbuf, (message *m_ptr) );
+_PROTOTYPE( int do_cprofile, (struct proc * caller, message *m_ptr) );
+_PROTOTYPE( int do_profbuf, (struct proc * caller, message *m_ptr) );
 
 #endif	/* SYSTEM_H */
 
diff --git a/kernel/system/do_abort.c b/kernel/system/do_abort.c
index efd7a1b4b..3d9213cfd 100644
--- a/kernel/system/do_abort.c
+++ b/kernel/system/do_abort.c
@@ -16,8 +16,7 @@
 /*===========================================================================*
  *				do_abort				     *
  *===========================================================================*/
-PUBLIC int do_abort(m_ptr)
-message *m_ptr;			/* pointer to request message */
+PUBLIC int do_abort(struct proc * caller, message * m_ptr)
 {
 /* Handle sys_abort. MINIX is unable to continue. This can originate e.g.
  * in the PM (normal abort or panic) or TTY (after CTRL-ALT-DEL).
@@ -31,7 +30,8 @@ message *m_ptr;			/* pointer to request message */
       int len;
       len = MIN(m_ptr->ABRT_MON_LEN, sizeof(paramsbuffer)-1);
 
-      if((p=data_copy(m_ptr->ABRT_MON_ENDPT, (vir_bytes) m_ptr->ABRT_MON_ADDR,
+      if((p=data_copy(m_ptr->ABRT_MON_ENDPT,
+		(vir_bytes) m_ptr->ABRT_MON_ADDR,
 		SYSTEM, (vir_bytes) paramsbuffer, len)) != OK) {
 		return p;
       }
diff --git a/kernel/system/do_copy.c b/kernel/system/do_copy.c
index cf42a75ee..16801370a 100644
--- a/kernel/system/do_copy.c
+++ b/kernel/system/do_copy.c
@@ -19,8 +19,7 @@
 /*===========================================================================*
  *				do_copy					     *
  *===========================================================================*/
-PUBLIC int do_copy(m_ptr)
-register message *m_ptr;	/* pointer to request message */
+PUBLIC int do_copy(struct proc * caller, message * m_ptr)
 {
 /* Handle sys_vircopy() and sys_physcopy().  Copy data using virtual or
  * physical addressing. Although a single handler function is used, there 
@@ -86,7 +85,8 @@ register message *m_ptr;	/* pointer to request message */
   if (bytes != (phys_bytes) (vir_bytes) bytes) return(E2BIG);
 
   /* Now try to make the actual virtual copy. */
-  return( virtual_copy_vmcheck(&vir_addr[_SRC_], &vir_addr[_DST_], bytes) );
+  return( virtual_copy_vmcheck(caller, &vir_addr[_SRC_],
+			  	&vir_addr[_DST_], bytes) );
 }
 #endif /* (USE_VIRCOPY || USE_PHYSCOPY) */
 
diff --git a/kernel/system/do_cprofile.c b/kernel/system/do_cprofile.c
index f100aa72d..12734c490 100644
--- a/kernel/system/do_cprofile.c
+++ b/kernel/system/do_cprofile.c
@@ -19,8 +19,7 @@
 /*===========================================================================*
  *				do_cprofile				     *
  *===========================================================================*/
-PUBLIC int do_cprofile(m_ptr)
-register message *m_ptr;    /* pointer to request message */
+PUBLIC int do_cprofile(struct proc * caller, message * m_ptr)
 {
   int proc_nr, i;
   phys_bytes len;
diff --git a/kernel/system/do_devio.c b/kernel/system/do_devio.c
index 210d7618c..fcb3abc5c 100644
--- a/kernel/system/do_devio.c
+++ b/kernel/system/do_devio.c
@@ -17,11 +17,8 @@
 /*===========================================================================*
  *			        do_devio                                     *
  *===========================================================================*/
-PUBLIC int do_devio(
-    register message *m_ptr	/* pointer to request message */
-)
+PUBLIC int do_devio(struct proc * caller, message * m_ptr)
 {
-    struct proc *rp;
     struct priv *privp;
     port_t port;
     struct io_range *iorp;
@@ -39,8 +36,7 @@ PUBLIC int do_devio(
 	default: size= 4; break;	/* Be conservative */
     }
 
-    rp= proc_addr(who_p);
-    privp= priv(rp);
+    privp= priv(caller);
     if (!privp)
     {
 	kprintf("no priv structure!\n");
diff --git a/kernel/system/do_endksig.c b/kernel/system/do_endksig.c
index 73fd61c08..8025b2c5e 100644
--- a/kernel/system/do_endksig.c
+++ b/kernel/system/do_endksig.c
@@ -13,8 +13,7 @@
 /*===========================================================================*
  *			      do_endksig				     *
  *===========================================================================*/
-PUBLIC int do_endksig(m_ptr)
-message *m_ptr;			/* pointer to request message */
+PUBLIC int do_endksig(struct proc * caller, message * m_ptr)
 {
 /* Finish up after a kernel type signal, caused by a SYS_KILL message or a 
  * call to cause_sig by a task. This is called by the PM after processing a
diff --git a/kernel/system/do_exec.c b/kernel/system/do_exec.c
index 9f3dda409..c7b2c9053 100644
--- a/kernel/system/do_exec.c
+++ b/kernel/system/do_exec.c
@@ -16,8 +16,7 @@
 /*===========================================================================*
  *				do_exec					     *
  *===========================================================================*/
-PUBLIC int do_exec(m_ptr)
-register message *m_ptr;	/* pointer to request message */
+PUBLIC int do_exec(struct proc * caller, message * m_ptr)
 {
 /* Handle sys_exec().  A process has done a successful EXEC. Patch it up. */
   register struct proc *rp;
@@ -34,7 +33,7 @@ register message *m_ptr;	/* pointer to request message */
   }
 
   /* Save command name for debugging, ps(1) output, etc. */
-  if(data_copy(who_e, (vir_bytes) m_ptr->PR_NAME_PTR,
+  if(data_copy(caller->p_endpoint, (vir_bytes) m_ptr->PR_NAME_PTR,
 	SYSTEM, (vir_bytes) rp->p_name, (phys_bytes) P_NAME_LEN - 1) != OK)
   	strncpy(rp->p_name, "<unset>", P_NAME_LEN);
 
diff --git a/kernel/system/do_exit.c b/kernel/system/do_exit.c
index 20941ac6b..64f006287 100644
--- a/kernel/system/do_exit.c
+++ b/kernel/system/do_exit.c
@@ -16,8 +16,7 @@ FORWARD _PROTOTYPE( void clear_proc, (register struct proc *rc));
 /*===========================================================================*
  *				do_exit					     *
  *===========================================================================*/
-PUBLIC int do_exit(m_ptr)
-message *m_ptr;			/* pointer to request message */
+PUBLIC int do_exit(struct proc * caller, message * m_ptr)
 {
 /* Handle sys_exit. A user process has exited or a system process requests 
  * to exit. Only the PM can request other process slots to be cleared.
@@ -28,7 +27,7 @@ message *m_ptr;			/* pointer to request message */
   int exit_e;				
 
   /* Determine what process exited. User processes are handled here. */
-  if (PM_PROC_NR == who_p) {
+  if (PM_PROC_NR == caller->p_endpoint) {
       if (m_ptr->PR_ENDPT != SELF) { 		/* PM tries to exit self */
           if(!isokendpt(m_ptr->PR_ENDPT, &exit_e)) /* get exiting process */
 	     return EINVAL;
@@ -38,7 +37,7 @@ message *m_ptr;			/* pointer to request message */
   } 
 
   /* The PM or some other system process requested to be exited. */
-  clear_proc(proc_addr(who_p));
+  clear_proc(caller);
   return(EDONTREPLY);
 }
 
diff --git a/kernel/system/do_fork.c b/kernel/system/do_fork.c
index 95e0077ef..badce6e0d 100644
--- a/kernel/system/do_fork.c
+++ b/kernel/system/do_fork.c
@@ -20,8 +20,7 @@
 /*===========================================================================*
  *				do_fork					     *
  *===========================================================================*/
-PUBLIC int do_fork(m_ptr)
-register message *m_ptr;	/* pointer to request message */
+PUBLIC int do_fork(struct proc * caller, message * m_ptr)
 {
 /* Handle sys_fork().  PR_ENDPT has forked.  The child is PR_SLOT. */
 #if (_MINIX_CHIP == _CHIP_INTEL)
@@ -101,7 +100,7 @@ register message *m_ptr;	/* pointer to request message */
   m_ptr->PR_FORK_MSGADDR = (char *) rpp->p_delivermsg_vir;
 
   /* Install new map */
-  r = newmap(rpc, map_ptr);
+  r = newmap(caller, rpc, map_ptr);
   FIXLINMSG(rpc);
 
   /* Don't schedule process in VM mode until it has a new pagetable. */
diff --git a/kernel/system/do_getinfo.c b/kernel/system/do_getinfo.c
index 01290792a..93f88eac7 100644
--- a/kernel/system/do_getinfo.c
+++ b/kernel/system/do_getinfo.c
@@ -20,8 +20,7 @@
 /*===========================================================================*
  *			        do_getinfo				     *
  *===========================================================================*/
-PUBLIC int do_getinfo(m_ptr)
-register message *m_ptr;	/* pointer to request message */
+PUBLIC int do_getinfo(struct proc * caller, message * m_ptr)
 {
 /* Request system information to be copied to caller's address space. This
  * call simply copies entire data structures to the caller.
@@ -29,12 +28,9 @@ register message *m_ptr;	/* pointer to request message */
   size_t length;
   vir_bytes src_vir; 
   int nr_e, nr, r;
-  struct proc *caller;
   int wipe_rnd_bin = -1;
   struct exec e_hdr;
 
-  caller = proc_addr(who_p);
-
   /* Set source address and length based on request type. */
   switch (m_ptr->I_REQUEST) {
     case GET_MACHINE: {
@@ -79,7 +75,7 @@ register message *m_ptr;	/* pointer to request message */
     }
     case GET_PROC: {
         nr_e = (m_ptr->I_VAL_LEN2_E == SELF) ?
-		who_e : m_ptr->I_VAL_LEN2_E;
+		caller->p_endpoint : m_ptr->I_VAL_LEN2_E;
 	if(!isokendpt(nr_e, &nr)) return EINVAL; /* validate request */
         length = sizeof(struct proc);
         src_vir = (vir_bytes) proc_addr(nr);
@@ -87,7 +83,7 @@ register message *m_ptr;	/* pointer to request message */
     }
     case GET_PRIV: {
         nr_e = (m_ptr->I_VAL_LEN2_E == SELF) ?
-            who_e : m_ptr->I_VAL_LEN2_E;
+            caller->p_endpoint : m_ptr->I_VAL_LEN2_E;
         if(!isokendpt(nr_e, &nr)) return EINVAL; /* validate request */
         length = sizeof(struct priv);
         src_vir = (vir_bytes) priv_addr(nr_to_id(nr));
@@ -188,7 +184,7 @@ register message *m_ptr;	/* pointer to request message */
 
   /* Try to make the actual copy for the requested data. */
   if (m_ptr->I_VAL_LEN > 0 && length > m_ptr->I_VAL_LEN) return (E2BIG);
-  r = data_copy_vmcheck(SYSTEM, src_vir, who_e,
+  r = data_copy_vmcheck(caller, SYSTEM, src_vir, caller->p_endpoint,
 	(vir_bytes) m_ptr->I_VAL_PTR, length);
 
   if(r != OK) return r;
diff --git a/kernel/system/do_getksig.c b/kernel/system/do_getksig.c
index 13d2c8d93..8ce3879e2 100644
--- a/kernel/system/do_getksig.c
+++ b/kernel/system/do_getksig.c
@@ -15,8 +15,7 @@
 /*===========================================================================*
  *			      do_getksig				     *
  *===========================================================================*/
-PUBLIC int do_getksig(m_ptr)
-message *m_ptr;			/* pointer to request message */
+PUBLIC int do_getksig(struct proc * caller, message * m_ptr)
 {
 /* PM is ready to accept signals and repeatedly does a kernel call to get 
  * one. Find a process with pending signals. If no signals are available, 
diff --git a/kernel/system/do_irqctl.c b/kernel/system/do_irqctl.c
index d76f1d4b6..36c0a0e36 100644
--- a/kernel/system/do_irqctl.c
+++ b/kernel/system/do_irqctl.c
@@ -20,8 +20,7 @@ FORWARD _PROTOTYPE(int generic_handler, (irq_hook_t *hook));
 /*===========================================================================*
  *				do_irqctl				     *
  *===========================================================================*/
-PUBLIC int do_irqctl(m_ptr)
-register message *m_ptr;	/* pointer to request message */
+PUBLIC int do_irqctl(struct proc * caller, message * m_ptr)
 {
   /* Dismember the request message. */
   int irq_vec;
@@ -30,7 +29,6 @@ register message *m_ptr;	/* pointer to request message */
   int r = OK;
   int i;
   irq_hook_t *hook_ptr;
-  struct proc *rp;
   struct priv *privp;
 
   /* Hook identifiers start at 1 and end at NR_IRQ_HOOKS. */
@@ -61,8 +59,7 @@ register message *m_ptr;	/* pointer to request message */
       /* Check if IRQ line is acceptable. */
       if (irq_vec < 0 || irq_vec >= NR_IRQ_VECTORS) return(EINVAL);
 
-      rp= proc_addr(who_p);
-      privp= priv(rp);
+      privp= priv(caller);
       if (!privp)
       {
 	kprintf("do_irqctl: no priv structure!\n");
diff --git a/kernel/system/do_kill.c b/kernel/system/do_kill.c
index ac27db68c..04758a860 100644
--- a/kernel/system/do_kill.c
+++ b/kernel/system/do_kill.c
@@ -14,8 +14,7 @@
 /*===========================================================================*
  *			          do_kill				     *
  *===========================================================================*/
-PUBLIC int do_kill(m_ptr)
-message *m_ptr;			/* pointer to request message */
+PUBLIC int do_kill(struct proc * caller, message * m_ptr)
 {
 /* Handle sys_kill(). Cause a signal to be sent to a process. The PM is the
  * central server where all signals are processed and handler policies can
diff --git a/kernel/system/do_memset.c b/kernel/system/do_memset.c
index bf5d0b473..8fcfae1de 100644
--- a/kernel/system/do_memset.c
+++ b/kernel/system/do_memset.c
@@ -14,8 +14,7 @@
 /*===========================================================================*
  *				do_memset				     *
  *===========================================================================*/
-PUBLIC int do_memset(m_ptr)
-register message *m_ptr;
+PUBLIC int do_memset(struct proc * caller, message * m_ptr)
 {
 /* Handle sys_memset(). This writes a pattern into the specified memory. */
   unsigned char c = m_ptr->MEM_PATTERN;
diff --git a/kernel/system/do_newmap.c b/kernel/system/do_newmap.c
index ca87a528d..848147bf5 100644
--- a/kernel/system/do_newmap.c
+++ b/kernel/system/do_newmap.c
@@ -13,11 +13,10 @@
 /*===========================================================================*
  *				do_newmap				     *
  *===========================================================================*/
-PUBLIC int do_newmap(m_ptr)
-message *m_ptr;			/* pointer to request message */
+PUBLIC int do_newmap(struct proc * caller, message * m_ptr)
 {
 /* Handle sys_newmap().  Fetch the memory map. */
-  register struct proc *rp;	/* process whose map is to be loaded */
+  struct proc *rp;	/* process whose map is to be loaded */
   struct mem_map *map_ptr;	/* virtual address of map inside caller */
   int proc_nr;
 
@@ -26,20 +25,18 @@ message *m_ptr;			/* pointer to request message */
   if (iskerneln(proc_nr)) return(EPERM);
   rp = proc_addr(proc_nr);
 
-  return newmap(rp, map_ptr);
+  return newmap(caller, rp, map_ptr);
 }
 
 
 /*===========================================================================*
  *				newmap					     *
  *===========================================================================*/
-PUBLIC int newmap(rp, map_ptr)
-struct proc *rp;		/* process whose map is to be loaded */
-struct mem_map *map_ptr;	/* virtual address of map inside caller */
+PUBLIC int newmap(struct proc *caller, struct proc *rp, struct mem_map *map_ptr)
 {
   int r;
 /* Fetch the memory map. */
-  if((r=data_copy(who_e, (vir_bytes) map_ptr,
+  if((r=data_copy(caller->p_endpoint, (vir_bytes) map_ptr,
 	SYSTEM, (vir_bytes) rp->p_memmap, sizeof(rp->p_memmap))) != OK) {
 	kprintf("newmap: data_copy failed! (%d)\n", r);
 	return r;
diff --git a/kernel/system/do_nice.c b/kernel/system/do_nice.c
index b1d243580..556f05aae 100644
--- a/kernel/system/do_nice.c
+++ b/kernel/system/do_nice.c
@@ -14,7 +14,7 @@
 /*===========================================================================*
  *				  do_nice				     *
  *===========================================================================*/
-PUBLIC int do_nice(message *m_ptr)
+PUBLIC int do_nice(struct proc * caller, message * m_ptr)
 {
 /* Change process priority or stop the process. */
   int proc_nr, pri, new_q ;
diff --git a/kernel/system/do_privctl.c b/kernel/system/do_privctl.c
index 4cf90084c..2c3d83fe3 100644
--- a/kernel/system/do_privctl.c
+++ b/kernel/system/do_privctl.c
@@ -11,20 +11,19 @@
 #include "../ipc.h"
 #include <signal.h>
 #include <string.h>
+#include <minix/endpoint.h>
 
 #if USE_PRIVCTL
 
 /*===========================================================================*
  *				do_privctl				     *
  *===========================================================================*/
-PUBLIC int do_privctl(m_ptr)
-message *m_ptr;			/* pointer to request message */
+PUBLIC int do_privctl(struct proc * caller, message * m_ptr)
 {
 /* Handle sys_privctl(). Update a process' privileges. If the process is not
  * yet a system process, make sure it gets its own privilege structure.
  */
-  register struct proc *caller_ptr;
-  register struct proc *rp;
+  struct proc *rp;
   int proc_nr;
   int priv_id;
   int ipc_to_m, kcalls;
@@ -39,9 +38,8 @@ message *m_ptr;			/* pointer to request message */
    * running by the RTS_NO_PRIV flag. This flag is set when a privileged process
    * forks. 
    */
-  caller_ptr = proc_addr(who_p);
-  if (! (priv(caller_ptr)->s_flags & SYS_PROC)) return(EPERM); 
-  if(m_ptr->CTL_ENDPT == SELF) proc_nr = who_p;
+  if (! (priv(caller)->s_flags & SYS_PROC)) return(EPERM);
+  if(m_ptr->CTL_ENDPT == SELF) proc_nr = _ENDPOINT_P(caller->p_endpoint);
   else if(!isokendpt(m_ptr->CTL_ENDPT, &proc_nr)) return(EINVAL);
   rp = proc_addr(proc_nr);
 
@@ -72,7 +70,7 @@ message *m_ptr;			/* pointer to request message */
 	if (m_ptr->CTL_ARG_PTR)
 	{
 		/* Copy privilege structure from caller */
-		if((r=data_copy(who_e, (vir_bytes) m_ptr->CTL_ARG_PTR,
+		if((r=data_copy(caller->p_endpoint, (vir_bytes) m_ptr->CTL_ARG_PTR,
 			SYSTEM, (vir_bytes) &priv, sizeof(priv))) != OK)
 			return r;
 
@@ -93,7 +91,7 @@ message *m_ptr;			/* pointer to request message */
 		return(i);
 	}
 	priv_id = priv(rp)->s_id;		/* backup privilege id */
-	*priv(rp) = *priv(caller_ptr);		/* copy from caller */
+	*priv(rp) = *priv(caller);		/* copy from caller */
 	priv(rp)->s_id = priv_id;		/* restore privilege id */
 	priv(rp)->s_proc_nr = proc_nr;		/* reassociate process nr */
 
@@ -227,7 +225,7 @@ message *m_ptr;			/* pointer to request message */
 #endif
 
 	/* Get the I/O range */
-	data_copy(who_e, (vir_bytes) m_ptr->CTL_ARG_PTR,
+	data_copy(caller->p_endpoint, (vir_bytes) m_ptr->CTL_ARG_PTR,
 		SYSTEM, (vir_bytes) &io_range, sizeof(io_range));
 	priv(rp)->s_flags |= CHECK_IO_PORT;	/* Check I/O accesses */
 	i= priv(rp)->s_nr_io_range;
@@ -249,7 +247,7 @@ message *m_ptr;			/* pointer to request message */
 		return EPERM;
 
 	/* Get the memory range */
-	if((r=data_copy(who_e, (vir_bytes) m_ptr->CTL_ARG_PTR,
+	if((r=data_copy(caller->p_endpoint, (vir_bytes) m_ptr->CTL_ARG_PTR,
 		SYSTEM, (vir_bytes) &mem_range, sizeof(mem_range))) != OK)
 		return r;
 	priv(rp)->s_flags |= CHECK_MEM;	/* Check memory mappings */
@@ -271,7 +269,7 @@ message *m_ptr;			/* pointer to request message */
 	if (!(priv(rp)->s_flags & SYS_PROC))
 		return EPERM;
 
-	data_copy(who_e, (vir_bytes) m_ptr->CTL_ARG_PTR,
+	data_copy(caller->p_endpoint, (vir_bytes) m_ptr->CTL_ARG_PTR,
 		SYSTEM, (vir_bytes) &irq, sizeof(irq));
 	priv(rp)->s_flags |= CHECK_IRQ;	/* Check IRQs */
 
diff --git a/kernel/system/do_profbuf.c b/kernel/system/do_profbuf.c
index 4ce308f1f..3d77757f4 100644
--- a/kernel/system/do_profbuf.c
+++ b/kernel/system/do_profbuf.c
@@ -14,8 +14,7 @@
 /*===========================================================================*
  *				do_profbuf				     *
  *===========================================================================*/
-PUBLIC int do_profbuf(m_ptr)
-register message *m_ptr;    /* pointer to request message */
+PUBLIC int do_profbuf(struct proc * caller, message * m_ptr)
 {
 /* This kernel call is used by profiled system processes when Call
  * Profiling is enabled. It is called on the first execution of procentry.
@@ -35,7 +34,7 @@ register message *m_ptr;    /* pointer to request message */
 
   rp = proc_addr(proc_nr);
 
-  cprof_proc_info[cprof_procs_no].endpt = who_e;
+  cprof_proc_info[cprof_procs_no].endpt = caller->p_endpoint;
   cprof_proc_info[cprof_procs_no].name = rp->p_name;
 
   cprof_proc_info[cprof_procs_no].ctl_v = (vir_bytes) m_ptr->PROF_CTL_PTR;
diff --git a/kernel/system/do_runctl.c b/kernel/system/do_runctl.c
index d5592b236..c384a2997 100644
--- a/kernel/system/do_runctl.c
+++ b/kernel/system/do_runctl.c
@@ -14,7 +14,7 @@
 /*===========================================================================*
  *				  do_runctl				     *
  *===========================================================================*/
-PUBLIC int do_runctl(message *m_ptr)
+PUBLIC int do_runctl(struct proc * caller, message * m_ptr)
 {
 /* Control a process's RTS_PROC_STOP flag. Used for process management.
  * If the process is queued sending a message or stopped for system call
diff --git a/kernel/system/do_safecopy.c b/kernel/system/do_safecopy.c
index 402941e0e..93fcabd50 100644
--- a/kernel/system/do_safecopy.c
+++ b/kernel/system/do_safecopy.c
@@ -25,7 +25,8 @@
 
 #define USE_COW_SAFECOPY 0
 
-FORWARD _PROTOTYPE(int safecopy, (endpoint_t, endpoint_t, cp_grant_id_t, int, int, size_t, vir_bytes, vir_bytes, int));
+FORWARD _PROTOTYPE(int safecopy, (struct proc *, endpoint_t, endpoint_t,
+		cp_grant_id_t, int, int, size_t, vir_bytes, vir_bytes, int));
 
 #define HASGRANTTABLE(gr) \
 	(!RTS_ISSET(gr, RTS_NO_PRIV) && priv(gr) && priv(gr)->s_grant_table > 0)
@@ -217,8 +218,9 @@ endpoint_t *e_granter;		/* new granter (magic grants) */
 /*===========================================================================*
  *				safecopy				     *
  *===========================================================================*/
-PRIVATE int safecopy(granter, grantee, grantid, src_seg, dst_seg, bytes,
+PRIVATE int safecopy(caller, granter, grantee, grantid, src_seg, dst_seg, bytes,
 	g_offset, addr, access)
+struct proc * caller;
 endpoint_t granter, grantee;
 cp_grant_id_t grantid;
 int src_seg, dst_seg;
@@ -232,8 +234,10 @@ int access;			/* CPF_READ for a copy from granter to grantee, CPF_WRITE
 	static vir_bytes v_offset;
 	endpoint_t new_granter, *src, *dst;
 	struct proc *granter_p;
-	vir_bytes size;
 	int r;
+#if USE_COW_SAFECOPY
+	vir_bytes size;
+#endif
 
 	/* See if there is a reasonable grant table. */
 	if(!(granter_p = endpoint_lookup(granter))) return EINVAL;
@@ -286,13 +290,13 @@ int access;			/* CPF_READ for a copy from granter to grantee, CPF_WRITE
 		/* Give up on COW immediately when offsets are not aligned
 		 * or we are copying less than a page.
 		 */
-		return virtual_copy_vmcheck(&v_src, &v_dst, bytes);
+		return virtual_copy_vmcheck(caller, &v_src, &v_dst, bytes);
 	}
 
 	if((size = v_offset % CLICK_SIZE) != 0) {
 		/* Normal copy for everything before the first page boundary. */
 		size = CLICK_SIZE - size;
-		r = virtual_copy_vmcheck(&v_src, &v_dst, size);
+		r = virtual_copy_vmcheck(caller, &v_src, &v_dst, size);
 		if(r != OK)
 			return r;
 		v_src.offset += size;
@@ -314,22 +318,21 @@ int access;			/* CPF_READ for a copy from granter to grantee, CPF_WRITE
 	}
 	if(bytes != 0) {
 		/* Normal copy for everything after the last page boundary. */
-		r = virtual_copy_vmcheck(&v_src, &v_dst, bytes);
+		r = virtual_copy_vmcheck(caller, &v_src, &v_dst, bytes);
 		if(r != OK)
 			return r;
 	}
 
 	return OK;
 #else
-	return virtual_copy_vmcheck(&v_src, &v_dst, bytes);
+	return virtual_copy_vmcheck(caller, &v_src, &v_dst, bytes);
 #endif
 }
 
 /*===========================================================================*
  *				do_safecopy				     *
  *===========================================================================*/
-PUBLIC int do_safecopy(m_ptr)
-register message *m_ptr;	/* pointer to request message */
+PUBLIC int do_safecopy(struct proc * caller, message * m_ptr)
 {
 	static int access, src_seg, dst_seg;
 
@@ -344,16 +347,15 @@ register message *m_ptr;	/* pointer to request message */
 		access = CPF_WRITE;
 	} else minix_panic("Impossible system call nr. ", sys_call_code);
 
-	return safecopy(m_ptr->SCP_FROM_TO, who_e, m_ptr->SCP_GID,
-		src_seg, dst_seg, m_ptr->SCP_BYTES, m_ptr->SCP_OFFSET,
-		(vir_bytes) m_ptr->SCP_ADDRESS, access);
+	return safecopy(caller, m_ptr->SCP_FROM_TO, caller->p_endpoint,
+		m_ptr->SCP_GID, src_seg, dst_seg, m_ptr->SCP_BYTES,
+		m_ptr->SCP_OFFSET, (vir_bytes) m_ptr->SCP_ADDRESS, access);
 }
 
 /*===========================================================================*
  *				do_vsafecopy				     *
  *===========================================================================*/
-PUBLIC int do_vsafecopy(m_ptr)
-register message *m_ptr;	/* pointer to request message */
+PUBLIC int do_vsafecopy(struct proc * caller, message * m_ptr)
 {
 	static struct vscp_vec vec[SCPVEC_NR];
 	static struct vir_addr src, dst;
@@ -361,7 +363,7 @@ register message *m_ptr;	/* pointer to request message */
 	size_t bytes;
 
 	/* Set vector copy parameters. */
-	src.proc_nr_e = who_e;
+	src.proc_nr_e = caller->p_endpoint;
 	src.offset = (vir_bytes) m_ptr->VSCP_VEC_ADDR;
 	src.segment = dst.segment = D;
 	dst.proc_nr_e = SYSTEM;
@@ -372,7 +374,7 @@ register message *m_ptr;	/* pointer to request message */
 	bytes = els * sizeof(struct vscp_vec);
 
 	/* Obtain vector of copies. */
-	if((r=virtual_copy_vmcheck(&src, &dst, bytes)) != OK)
+	if((r=virtual_copy_vmcheck(caller, &src, &dst, bytes)) != OK)
 		return r;
 
 	/* Perform safecopies. */
@@ -387,12 +389,13 @@ register message *m_ptr;	/* pointer to request message */
 			granter = vec[i].v_from;
 		} else {
 			kprintf("vsafecopy: %d: element %d/%d: no SELF found\n",
-				who_e, i, els);
+				caller->p_endpoint, i, els);
 			return EINVAL;
 		}
 
 		/* Do safecopy for this element. */
-		if((r=safecopy(granter, who_e, vec[i].v_gid, D, D,
+		if((r=safecopy(caller, granter, caller->p_endpoint,
+			vec[i].v_gid, D, D,
 			vec[i].v_bytes, vec[i].v_offset,
 			vec[i].v_addr, access)) != OK) {
 			return r;
diff --git a/kernel/system/do_safemap.c b/kernel/system/do_safemap.c
index 403f8638f..82f12569f 100644
--- a/kernel/system/do_safemap.c
+++ b/kernel/system/do_safemap.c
@@ -115,17 +115,17 @@ static int clear_info(struct map_info_s *p)
 /*===========================================================================*
  *				map_invoke_vm				     *
  *===========================================================================*/
-PUBLIC int map_invoke_vm(int req_type, /* VMPTYPE_... COWMAP, SMAP, SUNMAP */
-		endpoint_t end_d, int seg_d, vir_bytes off_d,
-		endpoint_t end_s, int seg_s, vir_bytes off_s,
-		size_t size, int flag)
+PUBLIC int map_invoke_vm(struct proc * caller,
+			int req_type, /* VMPTYPE_... COWMAP, SMAP, SUNMAP */
+			endpoint_t end_d, int seg_d, vir_bytes off_d,
+			endpoint_t end_s, int seg_s, vir_bytes off_s,
+			size_t size, int flag)
 {
-	struct proc *caller, *src, *dst;
+	struct proc *src, *dst;
 	phys_bytes lin_src, lin_dst;
 
 	src = endpoint_lookup(end_s);
 	dst = endpoint_lookup(end_d);
-	caller = endpoint_lookup(who_e);
 
 	lin_src = umap_local(src, seg_s, off_s, size);
 	lin_dst = umap_local(dst, seg_d, off_d, size);
@@ -170,8 +170,7 @@ PUBLIC int map_invoke_vm(int req_type, /* VMPTYPE_... COWMAP, SMAP, SUNMAP */
 /*===========================================================================*
  *				do_safemap				     *
  *===========================================================================*/
-PUBLIC int do_safemap(m_ptr)
-register message *m_ptr;
+PUBLIC int do_safemap(struct proc * caller, message * m_ptr)
 {
 	endpoint_t grantor	= m_ptr->SMAP_EP;
 	cp_grant_id_t gid	= m_ptr->SMAP_GID;
@@ -199,42 +198,42 @@ register message *m_ptr;
 	 */
 	if(flag != 0)
 		access |= CPF_WRITE;
-	r = verify_grant(grantor, who_e, gid, bytes, access,
+	r = verify_grant(grantor, caller->p_endpoint, gid, bytes, access,
 		offset, &offset_result, &new_grantor);
 	if(r != OK) {
 		kprintf("verify_grant for gid %d from %d to %d failed: %d\n",
-			gid, grantor, who_e, r);
+			gid, grantor, caller->p_endpoint, r);
 		return r;
 	}
 
 	/* Add map info. */
-	r = add_info(new_grantor, who_e, gid, offset, offset_result, seg,
-		address, bytes);
+	r = add_info(new_grantor, caller->p_endpoint, gid, offset,
+			offset_result, seg, address, bytes);
 	if(r != OK)
 		return r;
 
 	/* Invoke VM. */
-	return map_invoke_vm(VMPTYPE_SMAP,
-		who_e, seg, address, new_grantor, D, offset_result, bytes,flag);
+	return map_invoke_vm(caller, VMPTYPE_SMAP,
+		caller->p_endpoint, seg, address, new_grantor, D, offset_result, bytes,flag);
 }
 
 /*===========================================================================*
  *				safeunmap				     *
  *===========================================================================*/
-PRIVATE int safeunmap(struct map_info_s *p)
+PRIVATE int safeunmap(struct proc * caller, struct map_info_s *p)
 {
 	vir_bytes offset_result;
 	endpoint_t new_grantor;
 	int r;
 
-	r = verify_grant(p->grantor, p->grantee, p->gid, p->bytes, CPF_MAP,
-		p->offset, &offset_result, &new_grantor);
+	r = verify_grant(p->grantor, p->grantee, p->gid, p->bytes,
+			CPF_MAP, p->offset, &offset_result, &new_grantor);
 	if(r != OK) {
 	    kprintf("safeunmap: error in verify_grant.\n");
 		return r;
 	}
 
-	r = map_invoke_vm(VMPTYPE_SUNMAP,
+	r = map_invoke_vm(caller, VMPTYPE_SUNMAP,
 		p->grantee, p->seg, p->address,
 		new_grantor, D, offset_result,
 		p->bytes, 0);
@@ -249,16 +248,15 @@ PRIVATE int safeunmap(struct map_info_s *p)
 /*===========================================================================*
  *				do_saferevmap				     *
  *===========================================================================*/
-PUBLIC int do_saferevmap(m_ptr)
-register message *m_ptr;
+PUBLIC int do_saferevmap(struct proc * caller, message * m_ptr)
 {
 	struct map_info_s *p;
 	int flag = m_ptr->SMAP_FLAG;
 	int arg = m_ptr->SMAP_GID; /* gid or address_Dseg */
 	int r;
 
-	while((p = get_revoke_info(who_e, flag, arg)) != NULL) {
-		if((r = safeunmap(p)) != OK)
+	while((p = get_revoke_info(caller->p_endpoint, flag, arg)) != NULL) {
+		if((r = safeunmap(caller, p)) != OK)
 			return r;
 	}
 	return OK;
@@ -267,16 +265,15 @@ register message *m_ptr;
 /*===========================================================================*
  *				do_safeunmap				     *
  *===========================================================================*/
-PUBLIC int do_safeunmap(m_ptr)
-register message *m_ptr;
+PUBLIC int do_safeunmap(struct proc * caller, message * m_ptr)
 {
 	vir_bytes address = m_ptr->SMAP_ADDRESS;
 	int seg = (int)m_ptr->SMAP_SEG;
 	struct map_info_s *p;
 	int r;
 
-	while((p = get_unmap_info(who_e, seg, address)) != NULL) {
-		if((r = safeunmap(p)) != OK)
+	while((p = get_unmap_info(caller->p_endpoint, seg, address)) != NULL) {
+		if((r = safeunmap(caller, p)) != OK)
 			return r;
 	}
 	return OK;
diff --git a/kernel/system/do_segctl.c b/kernel/system/do_segctl.c
index df723a837..ccf85bea2 100644
--- a/kernel/system/do_segctl.c
+++ b/kernel/system/do_segctl.c
@@ -15,8 +15,7 @@
 /*===========================================================================*
  *			        do_segctl				     *
  *===========================================================================*/
-PUBLIC int do_segctl(m_ptr)
-register message *m_ptr;	/* pointer to request message */
+PUBLIC int do_segctl(struct proc * caller, message * m_ptr)
 {
 /* Return a segment selector and offset that can be used to reach a physical
  * address, for use by a driver doing memory I/O in the A0000 - DFFFF range.
@@ -24,26 +23,24 @@ register message *m_ptr;	/* pointer to request message */
   u32_t selector;
   vir_bytes offset;
   int i, index;
-  register struct proc *rp;
   phys_bytes phys = (phys_bytes) m_ptr->SEG_PHYS;
   vir_bytes size = (vir_bytes) m_ptr->SEG_SIZE;
   int result;
 
   /* First check if there is a slot available for this segment. */
-  rp = proc_addr(who_p);
   index = -1;
   for (i=0; i < NR_REMOTE_SEGS; i++) {
-      if (! rp->p_priv->s_farmem[i].in_use) {
+      if (! caller->p_priv->s_farmem[i].in_use) {
           index = i; 
-          rp->p_priv->s_farmem[i].in_use = TRUE;
-          rp->p_priv->s_farmem[i].mem_phys = phys;
-          rp->p_priv->s_farmem[i].mem_len = size;
+          caller->p_priv->s_farmem[i].in_use = TRUE;
+          caller->p_priv->s_farmem[i].mem_phys = phys;
+          caller->p_priv->s_farmem[i].mem_len = size;
           break;
       }
   }
   if (index < 0) return(ENOSPC);
 
-       offset = alloc_remote_segment(&selector, &rp->p_seg,
+       offset = alloc_remote_segment(&selector, &caller->p_seg,
 		i, phys, size, USER_PRIVILEGE);
        result = OK;          
 
diff --git a/kernel/system/do_setalarm.c b/kernel/system/do_setalarm.c
index 98f756028..4d2e2f5bb 100644
--- a/kernel/system/do_setalarm.c
+++ b/kernel/system/do_setalarm.c
@@ -18,11 +18,9 @@ FORWARD _PROTOTYPE( void cause_alarm, (timer_t *tp) );
 /*===========================================================================*
  *				do_setalarm				     *
  *===========================================================================*/
-PUBLIC int do_setalarm(m_ptr)
-message *m_ptr;			/* pointer to request message */
+PUBLIC int do_setalarm(struct proc * caller, message * m_ptr)
 {
 /* A process requests a synchronous alarm, or wants to cancel its alarm. */
-  register struct proc *rp;	/* pointer to requesting process */
   long exp_time;		/* expiration time for this alarm */
   int use_abs_time;		/* use absolute or relative time */
   timer_t *tp;			/* the process' timer structure */
@@ -31,11 +29,10 @@ message *m_ptr;			/* pointer to request message */
   /* Extract shared parameters from the request message. */
   exp_time = m_ptr->ALRM_EXP_TIME;	/* alarm's expiration time */
   use_abs_time = m_ptr->ALRM_ABS_TIME;	/* flag for absolute time */
-  rp = proc_addr(who_p);
-  if (! (priv(rp)->s_flags & SYS_PROC)) return(EPERM);
+  if (! (priv(caller)->s_flags & SYS_PROC)) return(EPERM);
 
   /* Get the timer structure and set the parameters for this alarm. */
-  tp = &(priv(rp)->s_alarm_timer);	
+  tp = &(priv(caller)->s_alarm_timer);
   tmr_arg(tp)->ta_int = m_ptr->m_source;
   tp->tmr_func = cause_alarm; 
 
diff --git a/kernel/system/do_setgrant.c b/kernel/system/do_setgrant.c
index b43eaddf3..f2584323f 100644
--- a/kernel/system/do_setgrant.c
+++ b/kernel/system/do_setgrant.c
@@ -12,20 +12,15 @@
 /*===========================================================================*
  *				do_setgrant				     *
  *===========================================================================*/
-PUBLIC int do_setgrant(m_ptr)
-message *m_ptr;
+PUBLIC int do_setgrant(struct proc * caller, message * m_ptr)
 {
-	struct proc *rp;
 	int r;
 
-	/* Who wants to set a parameter? */
-	rp = proc_addr(who_p);
-
 	/* Copy grant table set in priv. struct. */
-	if (RTS_ISSET(rp, RTS_NO_PRIV) || !(priv(rp))) {
+	if (RTS_ISSET(caller, RTS_NO_PRIV) || !(priv(caller))) {
 		r = EPERM;
 	} else {
-		_K_SET_GRANT_TABLE(rp, 
+		_K_SET_GRANT_TABLE(caller,
 			(vir_bytes) m_ptr->SG_ADDR,
 			m_ptr->SG_SIZE);
 		r = OK;
diff --git a/kernel/system/do_sigreturn.c b/kernel/system/do_sigreturn.c
index 93bf1f450..b3f3480f4 100644
--- a/kernel/system/do_sigreturn.c
+++ b/kernel/system/do_sigreturn.c
@@ -17,8 +17,7 @@
 /*===========================================================================*
  *			      do_sigreturn				     *
  *===========================================================================*/
-PUBLIC int do_sigreturn(m_ptr)
-message *m_ptr;			/* pointer to request message */
+PUBLIC int do_sigreturn(struct proc * caller, message * m_ptr)
 {
 /* POSIX style signals require sys_sigreturn to put things in order before 
  * the signalled process can resume execution
diff --git a/kernel/system/do_sigsend.c b/kernel/system/do_sigsend.c
index 8b1feda63..ec4be8833 100644
--- a/kernel/system/do_sigsend.c
+++ b/kernel/system/do_sigsend.c
@@ -18,8 +18,7 @@
 /*===========================================================================*
  *			      do_sigsend				     *
  *===========================================================================*/
-PUBLIC int do_sigsend(m_ptr)
-message *m_ptr;			/* pointer to request message */
+PUBLIC int do_sigsend(struct proc * caller, message * m_ptr)
 {
 /* Handle sys_sigsend, POSIX-style signal handling. */
 
@@ -37,8 +36,9 @@ message *m_ptr;			/* pointer to request message */
   rp = proc_addr(proc_nr);
 
   /* Get the sigmsg structure into our address space.  */
-  if((r=data_copy_vmcheck(who_e, (vir_bytes) m_ptr->SIG_CTXT_PTR,
-	SYSTEM, (vir_bytes) &smsg, (phys_bytes) sizeof(struct sigmsg))) != OK)
+  if((r=data_copy_vmcheck(caller, caller->p_endpoint,
+		(vir_bytes) m_ptr->SIG_CTXT_PTR, SYSTEM, (vir_bytes) &smsg,
+		(phys_bytes) sizeof(struct sigmsg))) != OK)
 	return r;
 
   /* Compute the user stack pointer where sigcontext will be stored. */
@@ -57,7 +57,7 @@ message *m_ptr;			/* pointer to request message */
   sc.sc_flags = 0 | rp->p_misc_flags & MF_FPU_INITIALIZED;
 
   /* Copy the sigcontext structure to the user's stack. */
-  if((r=data_copy_vmcheck(SYSTEM, (vir_bytes) &sc, m_ptr->SIG_ENDPT,
+  if((r=data_copy_vmcheck(caller, SYSTEM, (vir_bytes) &sc, m_ptr->SIG_ENDPT,
 	(vir_bytes) scp, (vir_bytes) sizeof(struct sigcontext))) != OK)
       return r;
 
@@ -106,7 +106,7 @@ message *m_ptr;			/* pointer to request message */
   fr.sf_retadr = (void (*)()) smsg.sm_sigreturn;
 
   /* Copy the sigframe structure to the user's stack. */
-  if((r=data_copy_vmcheck(SYSTEM, (vir_bytes) &fr,
+  if((r=data_copy_vmcheck(caller, SYSTEM, (vir_bytes) &fr,
 	m_ptr->SIG_ENDPT, (vir_bytes) frp, 
       (vir_bytes) sizeof(struct sigframe))) != OK)
       return r;
@@ -119,8 +119,6 @@ message *m_ptr;			/* pointer to request message */
   rp->p_misc_flags &= ~MF_FPU_INITIALIZED;
 
   if(!RTS_ISSET(rp, RTS_PROC_STOP)) {
-	struct proc *caller;
-	caller = proc_addr(who_p);
 	kprintf("system: warning: sigsend a running process\n");
 	kprintf("caller stack: ");
 	proc_stacktrace(caller);
diff --git a/kernel/system/do_sprofile.c b/kernel/system/do_sprofile.c
index a7fbbfbb8..cfb713817 100644
--- a/kernel/system/do_sprofile.c
+++ b/kernel/system/do_sprofile.c
@@ -23,8 +23,7 @@ PRIVATE vir_bytes sprof_info_addr_vir;
 /*===========================================================================*
  *				do_sprofile				     *
  *===========================================================================*/
-PUBLIC int do_sprofile(m_ptr)
-register message *m_ptr;    /* pointer to request message */
+PUBLIC int do_sprofile(struct proc * caller, message * m_ptr)
 {
   int proc_nr;
 
diff --git a/kernel/system/do_stime.c b/kernel/system/do_stime.c
index e2560e0bf..8b1194faa 100644
--- a/kernel/system/do_stime.c
+++ b/kernel/system/do_stime.c
@@ -12,8 +12,7 @@
 /*===========================================================================*
  *				do_stime				     *
  *===========================================================================*/
-PUBLIC int do_stime(m_ptr)
-register message *m_ptr;	/* pointer to request message */
+PUBLIC int do_stime(struct proc * caller, message * m_ptr)
 {
   boottime= m_ptr->T_BOOTTIME;
   return(OK);
diff --git a/kernel/system/do_sysctl.c b/kernel/system/do_sysctl.c
index 24f39738b..2dcab01ac 100644
--- a/kernel/system/do_sysctl.c
+++ b/kernel/system/do_sysctl.c
@@ -12,16 +12,12 @@
 /*===========================================================================*
  *			        do_sysctl				     *
  *===========================================================================*/
-PUBLIC int do_sysctl(m_ptr)
-register message *m_ptr;	/* pointer to request message */
+PUBLIC int do_sysctl(struct proc * caller, message * m_ptr)
 {
   vir_bytes len, buf;
   static char mybuf[DIAG_BUFSIZE];
-  struct proc *caller;
   int s, i, proc_nr;
 
-  caller = proc_addr(who_p);
-
   switch (m_ptr->SYSCTL_CODE) {
     case SYSCTL_CODE_DIAG:
         buf = (vir_bytes) m_ptr->SYSCTL_ARG1;
@@ -31,7 +27,8 @@ register message *m_ptr;	/* pointer to request message */
 			caller->p_endpoint, len);
 		return EINVAL;
 	}
-	if((s=data_copy_vmcheck(who_e, buf, SYSTEM, (vir_bytes) mybuf, len)) != OK) {
+	if((s=data_copy_vmcheck(caller, caller->p_endpoint, buf, SYSTEM,
+					(vir_bytes) mybuf, len)) != OK) {
 		kprintf("do_sysctl: diag for %d: len %d: copy failed: %d\n",
 			caller->p_endpoint, len, s);
 		return s;
diff --git a/kernel/system/do_times.c b/kernel/system/do_times.c
index 36ecf00e9..93284bb4c 100644
--- a/kernel/system/do_times.c
+++ b/kernel/system/do_times.c
@@ -18,8 +18,7 @@
 /*===========================================================================*
  *				do_times				     *
  *===========================================================================*/
-PUBLIC int do_times(m_ptr)
-register message *m_ptr;	/* pointer to request message */
+PUBLIC int do_times(struct proc * caller, message * m_ptr)
 {
 /* Handle sys_times().  Retrieve the accounting information. */
   register struct proc *rp;
diff --git a/kernel/system/do_trace.c b/kernel/system/do_trace.c
index e785183b9..fca014609 100644
--- a/kernel/system/do_trace.c
+++ b/kernel/system/do_trace.c
@@ -16,8 +16,7 @@
 /*==========================================================================*
  *				do_trace				    *
  *==========================================================================*/
-PUBLIC int do_trace(m_ptr)
-register message *m_ptr;
+PUBLIC int do_trace(struct proc * caller, message * m_ptr)
 {
 /* Handle the debugging commands supported by the ptrace system call
  * The commands are:
@@ -61,7 +60,8 @@ register message *m_ptr;
 	toaddr.offset = (addr);				\
 	fromaddr.segment = D;				\
 	toaddr.segment = (seg);				\
-	if((r=virtual_copy_vmcheck(&fromaddr, &toaddr, length)) != OK) { \
+	if((r=virtual_copy_vmcheck(caller, &fromaddr,	\
+			&toaddr, length)) != OK) {	\
 		printf("Can't copy in sys_trace: %d\n", r);\
 		return r;\
 	}  \
@@ -76,7 +76,8 @@ register message *m_ptr;
 	toaddr.offset = (myaddr);			\
 	fromaddr.segment = (seg);			\
 	toaddr.segment = D;				\
-	if((r=virtual_copy_vmcheck(&fromaddr, &toaddr, length)) != OK) { \
+	if((r=virtual_copy_vmcheck(caller, &fromaddr,	\
+			&toaddr, length)) != OK) {	\
 		printf("Can't copy in sys_trace: %d\n", r);\
 		return r;\
 	}  \
diff --git a/kernel/system/do_umap.c b/kernel/system/do_umap.c
index 5bad38250..bd245ee9c 100644
--- a/kernel/system/do_umap.c
+++ b/kernel/system/do_umap.c
@@ -11,13 +11,14 @@
 
 #include "../system.h"
 
+#include <minix/endpoint.h>
+
 #if USE_UMAP
 
 /*==========================================================================*
  *				do_umap					    *
  *==========================================================================*/
-PUBLIC int do_umap(m_ptr)
-register message *m_ptr;	/* pointer to request message */
+PUBLIC int do_umap(struct proc * caller, message * m_ptr)
 {
 /* Map virtual address to physical, for non-kernel processes. */
   int seg_type = m_ptr->CP_SRC_SPACE & SEGMENT_TYPE;
@@ -28,20 +29,16 @@ register message *m_ptr;	/* pointer to request message */
   int proc_nr, r;
   int naughty = 0;
   phys_bytes phys_addr = 0, lin_addr = 0;
-  int caller_pn;
-  struct proc *targetpr, *caller;
+  struct proc *targetpr;
 
   /* Verify process number. */
   if (endpt == SELF)
-	proc_nr = who_p;
+	proc_nr = _ENDPOINT_P(caller->p_endpoint);
   else
 	if (! isokendpt(endpt, &proc_nr))
 		return(EINVAL);
   targetpr = proc_addr(proc_nr);
 
-  okendpt(who_e, &caller_pn);
-  caller = proc_addr(caller_pn);
-
   /* See which mapping should be made. */
   switch(seg_type) {
   case LOCAL_SEG:
@@ -110,7 +107,8 @@ register message *m_ptr;	/* pointer to request message */
   m_ptr->CP_DST_ADDR = phys_addr;
   if(naughty || phys_addr == 0) {
 	  kprintf("kernel: umap 0x%x done by %d / %s, pc 0x%lx, 0x%lx -> 0x%lx\n",
-		seg_type, who_e, caller->p_name, caller->p_reg.pc, offset, phys_addr);
+		seg_type, caller->p_endpoint, caller->p_name,
+		caller->p_reg.pc, offset, phys_addr);
 	kprintf("caller stack: ");
 	proc_stacktrace(caller);
   }
diff --git a/kernel/system/do_unused.c b/kernel/system/do_unused.c
index 2a9163308..2cb6d4e9f 100644
--- a/kernel/system/do_unused.c
+++ b/kernel/system/do_unused.c
@@ -7,10 +7,10 @@
 /*===========================================================================*
  *			          do_unused				     *
  *===========================================================================*/
-PUBLIC int do_unused(m)
-message *m;				/* pointer to request message */
+PUBLIC int do_unused(struct proc * caller, message * m_ptr)
 {
-  kprintf("SYSTEM: got unused request %d from %d\n", m->m_type, m->m_source);
+  kprintf("SYSTEM: got unused request %d from %d\n",
+		  m_ptr->m_type, m_ptr->m_source);
   return(EBADREQUEST);			/* illegal message type */
 }
 
diff --git a/kernel/system/do_vdevio.c b/kernel/system/do_vdevio.c
index bb6962f6f..2cf12afaf 100644
--- a/kernel/system/do_vdevio.c
+++ b/kernel/system/do_vdevio.c
@@ -23,8 +23,7 @@ PRIVATE pvl_pair_t *pvl = (pvl_pair_t *) vdevio_buf;
 /*===========================================================================*
  *			        do_vdevio                                    *
  *===========================================================================*/
-PUBLIC int do_vdevio(m_ptr)
-register message *m_ptr;	/* pointer to request message */
+PUBLIC int do_vdevio(struct proc * caller, message * m_ptr)
 {
 /* Perform a series of device I/O on behalf of a non-kernel process. The 
  * I/O addresses and I/O values are fetched from and returned to some buffer
@@ -38,7 +37,6 @@ register message *m_ptr;	/* pointer to request message */
   port_t port;
   int i, j, io_size, nr_io_range;
   int io_dir, io_type;
-  struct proc *rp;
   struct priv *privp;
   struct io_range *iorp;
   int r;
@@ -68,12 +66,11 @@ register message *m_ptr;	/* pointer to request message */
   if (bytes > sizeof(vdevio_buf))  return(E2BIG);
 
   /* Copy (port,value)-pairs from user. */
-  if((r=data_copy(who_e, (vir_bytes) m_ptr->DIO_VEC_ADDR,
+  if((r=data_copy(caller->p_endpoint, (vir_bytes) m_ptr->DIO_VEC_ADDR,
     SYSTEM, (vir_bytes) vdevio_buf, bytes)) != OK)
 	return r;
 
-  rp= proc_addr(who_p);
-  privp= priv(rp);
+  privp= priv(caller);
   if (privp && (privp->s_flags & CHECK_IO_PORT))
   {
 	/* Check whether the I/O is allowed */
@@ -173,7 +170,7 @@ register message *m_ptr;	/* pointer to request message */
   /* Almost done, copy back results for input requests. */
   if (io_in) 
 	if((r=data_copy(SYSTEM, (vir_bytes) vdevio_buf, 
-	  who_e, (vir_bytes) m_ptr->DIO_VEC_ADDR,
+	  caller->p_endpoint, (vir_bytes) m_ptr->DIO_VEC_ADDR,
 	  (phys_bytes) bytes)) != OK)
 		return r;
   return(OK);
diff --git a/kernel/system/do_vmctl.c b/kernel/system/do_vmctl.c
index 4b4f8fd1f..a6a65c2e7 100644
--- a/kernel/system/do_vmctl.c
+++ b/kernel/system/do_vmctl.c
@@ -15,8 +15,7 @@
 /*===========================================================================*
  *				do_vmctl				     *
  *===========================================================================*/
-PUBLIC int do_vmctl(m_ptr)
-register message *m_ptr;	/* pointer to request message */
+PUBLIC int do_vmctl(struct proc * caller, message * m_ptr)
 {
   int proc_nr;
   endpoint_t ep = m_ptr->SVMCTL_WHO;
@@ -171,7 +170,7 @@ register message *m_ptr;	/* pointer to request message */
 			unlock;
 			return err;
 		}
-		if(newmap(p, (struct mem_map *) m_ptr->SVMCTL_VALUE) != OK)
+		if(newmap(caller, p, (struct mem_map *) m_ptr->SVMCTL_VALUE) != OK)
 			minix_panic("do_vmctl: newmap failed", NO_NUM);
 		FIXLINMSG(p);
 		vmassert(p->p_delivermsg_lin);
diff --git a/kernel/system/do_vtimer.c b/kernel/system/do_vtimer.c
index 50a957ab7..a85cf3b5a 100644
--- a/kernel/system/do_vtimer.c
+++ b/kernel/system/do_vtimer.c
@@ -18,11 +18,9 @@
 /*===========================================================================*
  *				do_vtimer				     *
  *===========================================================================*/
-PUBLIC int do_vtimer(m_ptr)
-message *m_ptr;			/* pointer to request message */
+PUBLIC int do_vtimer(struct proc * caller, message * m_ptr)
 {
 /* Set and/or retrieve the value of one of a process' virtual timers. */
-  struct proc *rrp;		/* pointer to requesting process */
   struct proc *rp;		/* pointer to process the timer belongs to */
   register int pt_flag;		/* the misc on/off flag for the req.d timer */
   register clock_t *pt_left;	/* pointer to the process' ticks-left field */ 
@@ -30,8 +28,7 @@ message *m_ptr;			/* pointer to request message */
   int proc_nr, proc_nr_e;
 
   /* The requesting process must be privileged. */
-  rrp = proc_addr(who_p);
-  if (! (priv(rrp)->s_flags & SYS_PROC)) return(EPERM);
+  if (! (priv(caller)->s_flags & SYS_PROC)) return(EPERM);
 
   if (m_ptr->VT_WHICH != VT_VIRTUAL && m_ptr->VT_WHICH != VT_PROF)
       return(EINVAL);