Use uvm_grow() to account for stack growth, rather than home-grown code

or nothing.
Inspired by a similar recent change in NetBSD.

13 files changed, 76 insertions, 159 deletions

diff --git a/sys/arch/alpha/alpha/trap.c b/sys/arch/alpha/alpha/trap.c
index 23e7aa56e74..a21d1de511c 100644
--- a/sys/arch/alpha/alpha/trap.c
+++ b/sys/arch/alpha/alpha/trap.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: trap.c,v 1.43 2003/11/13 08:19:20 miod Exp $ */
+/* $OpenBSD: trap.c,v 1.44 2004/12/06 20:12:21 miod Exp $ */
 /* $NetBSD: trap.c,v 1.52 2000/05/24 16:48:33 thorpej Exp $ */
 
 /*-
@@ -481,15 +481,10 @@ do_fault:
 			 * we need to reflect that as an access error.
 			 */
 			if (map != kernel_map &&
-			    (caddr_t)va >= vm->vm_maxsaddr &&
-			    va < USRSTACK) {
+			    (caddr_t)va >= vm->vm_maxsaddr) {
 				if (rv == 0) {
-					unsigned nss;
-	
-					nss = btoc(USRSTACK -
-					    (unsigned long)va);
-					if (nss > vm->vm_ssize)
-						vm->vm_ssize = nss;
+					if (p != NULL)
+					    uvm_grow(p, va);
 				} else if (rv == EACCES)
 					rv = EFAULT;
 			}
diff --git a/sys/arch/amd64/amd64/trap.c b/sys/arch/amd64/amd64/trap.c
index 91bb63f9afa..79c5f7c0869 100644
--- a/sys/arch/amd64/amd64/trap.c
+++ b/sys/arch/amd64/amd64/trap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: trap.c,v 1.3 2004/02/23 08:32:36 mickey Exp $	*/
+/*	$OpenBSD: trap.c,v 1.4 2004/12/06 20:12:23 miod Exp $	*/
 /*	$NetBSD: trap.c,v 1.2 2003/05/04 23:51:56 fvdl Exp $	*/
 
 /*-
@@ -404,7 +404,6 @@ copyfault:
 		struct vm_map *map;
 		vm_prot_t ftype;
 		extern struct vm_map *kernel_map;
-		unsigned long nss;
 
 		cr2 = rcr2();
 		KERNEL_PROC_LOCK(p);
@@ -440,25 +439,6 @@ faultcommon:
 		}
 #endif
 
-		nss = 0;
-		if ((caddr_t)va >= vm->vm_maxsaddr
-		    && (caddr_t)va < (caddr_t)VM_MAXUSER_ADDRESS
-		    && map != kernel_map) {
-			nss = btoc(USRSTACK-(unsigned long)va);
-			if (nss > (u_long)btoc(p->p_rlimit[RLIMIT_STACK].rlim_cur)) {
-				/*
-				 * We used to fail here. However, it may
-				 * just have been an mmap()ed page low
-				 * in the stack, which is legal. If it
-				 * wasn't, uvm_fault() will fail below.
-				 *
-				 * Set nss to 0, since this case is not
-				 * a "stack extension".
-				 */
-				nss = 0;
-			}
-		}
-
 		/* Fault the original page in. */
 		onfault = pcb->pcb_onfault;
 		pcb->pcb_onfault = NULL;
@@ -466,8 +446,8 @@ faultcommon:
 		    VM_FAULT_PROTECT : VM_FAULT_INVALID, ftype);
 		pcb->pcb_onfault = onfault;
 		if (error == 0) {
-			if (nss > (u_long)vm->vm_ssize)
-				vm->vm_ssize = nss;
+			if (map != kernel_map)
+				uvm_grow(p, va);
 
 			if (type == T_PAGEFLT) {
 				KERNEL_UNLOCK();
diff --git a/sys/arch/hp300/hp300/trap.c b/sys/arch/hp300/hp300/trap.c
index 9a9e1a6ebcc..e658888db29 100644
--- a/sys/arch/hp300/hp300/trap.c
+++ b/sys/arch/hp300/hp300/trap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: trap.c,v 1.44 2004/01/15 17:22:25 miod Exp $	*/
+/*	$OpenBSD: trap.c,v 1.45 2004/12/06 20:12:23 miod Exp $	*/
 /*	$NetBSD: trap.c,v 1.57 1998/02/16 20:58:31 thorpej Exp $	*/
 
 /*
@@ -653,11 +653,7 @@ dopanic:
 		if ((vm != NULL && (caddr_t)va >= vm->vm_maxsaddr)
 		    && map != kernel_map) {
 			if (rv == 0) {
-				unsigned nss;
-
-				nss = btoc(USRSTACK-(unsigned)va);
-				if (nss > vm->vm_ssize)
-					vm->vm_ssize = nss;
+				uvm_grow(p, va);
 			} else if (rv == EACCES)
 				rv = EFAULT;
 		}
diff --git a/sys/arch/hppa/hppa/trap.c b/sys/arch/hppa/hppa/trap.c
index 2b42af14fc2..022bcc0f97e 100644
--- a/sys/arch/hppa/hppa/trap.c
+++ b/sys/arch/hppa/hppa/trap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: trap.c,v 1.81 2004/09/14 22:44:58 mickey Exp $	*/
+/*	$OpenBSD: trap.c,v 1.82 2004/12/06 20:12:24 miod Exp $	*/
 
 /*
  * Copyright (c) 1998-2004 Michael Shalayeff
@@ -421,13 +421,10 @@ trap(type, frame)
 		 * error.
 		 */
 		if (space != HPPA_SID_KERNEL &&
-		    va < (vaddr_t)vm->vm_minsaddr &&
-		    va >= (vaddr_t)vm->vm_maxsaddr + ctob(vm->vm_ssize)) {
-			if (ret == 0) {
-				vsize_t nss = btoc(va - USRSTACK + NBPG - 1);
-				if (nss > vm->vm_ssize)
-					vm->vm_ssize = nss;
-			} else if (ret == EACCES)
+		    va < (vaddr_t)vm->vm_minsaddr) {
+			if (ret == 0)
+				uvm_grow(p, va);
+			else if (ret == EACCES)
 				ret = EFAULT;
 		}
 
diff --git a/sys/arch/i386/i386/trap.c b/sys/arch/i386/i386/trap.c
index a69e15501f7..e0aeb203bfb 100644
--- a/sys/arch/i386/i386/trap.c
+++ b/sys/arch/i386/i386/trap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: trap.c,v 1.66 2004/09/07 10:12:35 niklas Exp $	*/
+/*	$OpenBSD: trap.c,v 1.67 2004/12/06 20:12:24 miod Exp $	*/
 /*	$NetBSD: trap.c,v 1.95 1996/05/05 06:50:02 mycroft Exp $	*/
 
 /*-
@@ -476,7 +476,6 @@ trap(frame)
 		struct vmspace *vm;
 		struct vm_map *map;
 		int rv;
-		unsigned nss;
 
 		cr2 = rcr2();
 		KERNEL_PROC_LOCK(p);
@@ -506,32 +505,14 @@ trap(frame)
 		}
 #endif
 
-		nss = 0;
-		if ((caddr_t)va >= vm->vm_maxsaddr
-		    && (caddr_t)va < (caddr_t)VM_MAXUSER_ADDRESS
-		    && map != kernel_map) {
-			nss = btoc(USRSTACK-(unsigned)va);
-			if (nss > btoc(p->p_rlimit[RLIMIT_STACK].rlim_cur)) {
-				/*
-				 * We used to fail here. However, it may
-				 * just have been an mmap()ed page low
-				 * in the stack, which is legal. If it
-				 * wasn't, uvm_fault() will fail below.
-				 *
-				 * Set nss to 0, since this case is not
-				 * a "stack extension".
-				 */
-				nss = 0;
-			}
-		}
-
 		onfault = p->p_addr->u_pcb.pcb_onfault;
 		p->p_addr->u_pcb.pcb_onfault = NULL;
 		rv = uvm_fault(map, va, 0, ftype);
 		p->p_addr->u_pcb.pcb_onfault = onfault;
+
 		if (rv == 0) {
-			if (nss > vm->vm_ssize)
-				vm->vm_ssize = nss;
+			if (map != kernel_map)
+				uvm_grow(p, va);
 			if (type == T_PAGEFLT) {
 				KERNEL_UNLOCK();
 				return;
@@ -617,7 +598,6 @@ int
 trapwrite(unsigned int addr)
 {
 	vaddr_t va;
-	unsigned nss;
 	struct proc *p;
 	struct vmspace *vm;
 
@@ -625,20 +605,13 @@ trapwrite(unsigned int addr)
 	if (va >= VM_MAXUSER_ADDRESS)
 		return 1;
 
-	nss = 0;
 	p = curproc;
 	vm = p->p_vmspace;
-	if ((caddr_t)va >= vm->vm_maxsaddr) {
-		nss = btoc(USRSTACK-(unsigned)va);
-		if (nss > btoc(p->p_rlimit[RLIMIT_STACK].rlim_cur))
-			nss = 0;
-	}
 
 	if (uvm_fault(&vm->vm_map, va, 0, VM_PROT_READ | VM_PROT_WRITE))
 		return 1;
 
-	if (nss > vm->vm_ssize)
-		vm->vm_ssize = nss;
+	uvm_grow(p, va);
 
 	return 0;
 }
diff --git a/sys/arch/m88k/m88k/trap.c b/sys/arch/m88k/m88k/trap.c
index aa044746c15..bd627908897 100644
--- a/sys/arch/m88k/m88k/trap.c
+++ b/sys/arch/m88k/m88k/trap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: trap.c,v 1.14 2004/11/09 21:49:56 miod Exp $	*/
+/*	$OpenBSD: trap.c,v 1.15 2004/12/06 20:12:24 miod Exp $	*/
 /*
  * Copyright (c) 2004, Miodrag Vallat.
  * Copyright (c) 1998 Steve Murphree, Jr.
@@ -203,7 +203,7 @@ m88100_trap(unsigned type, struct trapframe *frame)
 	vm_prot_t ftype;
 	int fault_type, pbus_type;
 	u_long fault_code;
-	unsigned nss, fault_addr;
+	unsigned fault_addr;
 	struct vmspace *vm;
 	union sigval sv;
 	int result;
@@ -397,19 +397,16 @@ user_fault:
 			break;
 		default:
 			result = uvm_fault(map, va, VM_FAULT_INVALID, ftype);
-			if (result == EACCES)
-				result = EFAULT;
 			break;
 		}
 
 		p->p_addr->u_pcb.pcb_onfault = pcb_onfault;
 
 		if ((caddr_t)va >= vm->vm_maxsaddr) {
-			if (result == 0) {
-				nss = btoc(USRSTACK - va);/* XXX check this */
-				if (nss > vm->vm_ssize)
-					vm->vm_ssize = nss;
-			}
+			if (result == 0)
+				uvm_grow(p, va);
+			else if (result == EACCES)
+				result = EFAULT;
 		}
 
 		/*
@@ -610,7 +607,7 @@ m88110_trap(unsigned type, struct trapframe *frame)
 	vm_prot_t ftype;
 	int fault_type;
 	u_long fault_code;
-	unsigned nss, fault_addr;
+	unsigned fault_addr;
 	struct vmspace *vm;
 	union sigval sv;
 	int result;
@@ -863,8 +860,6 @@ m88110_user_fault:
 				/* segment or page fault */
 				result = uvm_fault(map, va, VM_FAULT_INVALID, ftype);
 				p->p_addr->u_pcb.pcb_onfault = pcb_onfault;
-				if (result == EACCES)
-					result = EFAULT;
 			} else
 			if (frame->tf_dsr & (CMMU_DSR_CP | CMMU_DSR_WA)) {
 				/* copyback or write allocate error */
@@ -911,8 +906,6 @@ m88110_user_fault:
 #endif
 					result = uvm_fault(map, va, VM_FAULT_INVALID, ftype);
 					p->p_addr->u_pcb.pcb_onfault = pcb_onfault;
-					if (result == EACCES)
-						result = EFAULT;
 				}
 			} else {
 #ifdef TRAPDEBUG
@@ -932,8 +925,6 @@ m88110_user_fault:
 				/* segment or page fault */
 				result = uvm_fault(map, va, VM_FAULT_INVALID, ftype);
 				p->p_addr->u_pcb.pcb_onfault = pcb_onfault;
-				if (result == EACCES)
-					result = EFAULT;
 			} else {
 #ifdef TRAPDEBUG
 				printf("Unexpected Instruction fault isr %x\n",
@@ -944,11 +935,10 @@ m88110_user_fault:
 		}
 
 		if ((caddr_t)va >= vm->vm_maxsaddr) {
-			if (result == 0) {
-				nss = btoc(USRSTACK - va);/* XXX check this */
-				if (nss > vm->vm_ssize)
-					vm->vm_ssize = nss;
-			}
+			if (result == 0)
+				uvm_grow(p, va);
+			else if (result == EACCES)
+				result = EFAULT;
 		}
 
 		/*
diff --git a/sys/arch/mac68k/mac68k/trap.c b/sys/arch/mac68k/mac68k/trap.c
index d3f9971fc26..610d9214806 100644
--- a/sys/arch/mac68k/mac68k/trap.c
+++ b/sys/arch/mac68k/mac68k/trap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: trap.c,v 1.41 2003/06/02 23:27:49 millert Exp $	*/
+/*	$OpenBSD: trap.c,v 1.42 2004/12/06 20:12:24 miod Exp $	*/
 /*	$NetBSD: trap.c,v 1.68 1998/12/22 08:47:07 scottr Exp $	*/
 
 /*
@@ -596,13 +596,9 @@ copyfault:
 		 */
 		if ((vm != NULL && (caddr_t)va >= vm->vm_maxsaddr)
 		    && map != kernel_map) {
-			if (rv == 0) {
-				u_int nss;
-
-				nss = btoc(USRSTACK-(unsigned)va);
-				if (nss > vm->vm_ssize)
-					vm->vm_ssize = nss;
-			} else if (rv == EACCES)
+			if (rv == 0)
+				uvm_grow(p, va);
+			else if (rv == EACCES)
 				rv = EFAULT;
 		}
 		if (rv == 0) {
@@ -633,9 +629,9 @@ copyfault:
 	}
 	sv.sival_ptr = (void *)v;
 	trapsignal(p, i, ucode, typ, sv);
+out:
 	if ((type & T_USER) == 0)
 		return;
-out:
 	userret(p, &frame, sticks, v, 1); 
 }
 
diff --git a/sys/arch/mips64/mips64/trap.c b/sys/arch/mips64/mips64/trap.c
index 105f494b3f0..b67f6829788 100644
--- a/sys/arch/mips64/mips64/trap.c
+++ b/sys/arch/mips64/mips64/trap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: trap.c,v 1.18 2004/11/11 19:00:37 kettenis Exp $	*/
+/*	$OpenBSD: trap.c,v 1.19 2004/12/06 20:12:24 miod Exp $	*/
 /* tracked to 1.23 */
 
 /*
@@ -273,7 +273,7 @@ trap(trapframe)
 		kernel_fault:
 			va = trunc_page((vaddr_t)trapframe->badvaddr);
 			rv = uvm_fault(kernel_map, trunc_page(va), 0, ftype);
-			if (rv == KERN_SUCCESS)
+			if (rv == 0)
 				return (trapframe->pc);
 			if ((i = p->p_addr->u_pcb.pcb_onfault) != 0) {
 				p->p_addr->u_pcb.pcb_onfault = 0;
@@ -327,16 +327,12 @@ printf("sp %p\n", trapframe->sp);
 		 * error.
 		 */
 		if ((caddr_t)va >= vm->vm_maxsaddr) {
-			if (rv == KERN_SUCCESS) {
-				unsigned nss;
-
-				nss = btoc(USRSTACK-(unsigned)va);
-				if (nss > vm->vm_ssize)
-					vm->vm_ssize = nss;
-			} else if (rv == KERN_PROTECTION_FAILURE)
-				rv = KERN_INVALID_ADDRESS;
+			if (rv == 0)
+				uvm_grow(p, va);
+			else if (rv == EACCES)
+				rv = EFAULT;
 		}
-		if (rv == KERN_SUCCESS) {
+		if (rv == 0) {
 			if (!USERMODE(trapframe->sr))
 				return (trapframe->pc);
 			goto out;
diff --git a/sys/arch/mvme68k/mvme68k/trap.c b/sys/arch/mvme68k/mvme68k/trap.c
index 396373cb3b9..e88700dfaee 100644
--- a/sys/arch/mvme68k/mvme68k/trap.c
+++ b/sys/arch/mvme68k/mvme68k/trap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: trap.c,v 1.55 2004/07/30 22:29:49 miod Exp $ */
+/*	$OpenBSD: trap.c,v 1.56 2004/12/06 20:12:25 miod Exp $ */
 
 /*
  * Copyright (c) 1995 Theo de Raadt
@@ -595,13 +595,9 @@ copyfault:
 			 */
 			if ((vm != NULL && (caddr_t)va >= vm->vm_maxsaddr)
 			    && map != kernel_map) {
-				if (rv == 0) {
-					u_int nss;
-
-					nss = btoc(USRSTACK-(u_int)va);
-					if (nss > vm->vm_ssize)
-						vm->vm_ssize = nss;
-				} else if (rv == EACCES)
+				if (rv == 0)
+					uvm_grow(p, va);
+				else if (rv == EACCES)
 					rv = EFAULT;
 			}
 			if (rv == 0) {
diff --git a/sys/arch/powerpc/powerpc/trap.c b/sys/arch/powerpc/powerpc/trap.c
index 9ec131f8e95..3b7168c2862 100644
--- a/sys/arch/powerpc/powerpc/trap.c
+++ b/sys/arch/powerpc/powerpc/trap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: trap.c,v 1.64 2004/08/05 20:56:24 pefo Exp $	*/
+/*	$OpenBSD: trap.c,v 1.65 2004/12/06 20:12:25 miod Exp $	*/
 /*	$NetBSD: trap.c,v 1.3 1996/10/13 03:31:37 christos Exp $	*/
 
 /*
@@ -364,8 +364,10 @@ printf("kern dsi on addr %x iar %x\n", frame->dar, frame->srr0);
 			} else
 				vftype = ftype = VM_PROT_READ;
 			if (uvm_fault(&p->p_vmspace->vm_map,
-				     trunc_page(frame->dar), 0, ftype) == 0)
+				     trunc_page(frame->dar), 0, ftype) == 0) {
+				uvm_grow(p, trunc_page(frame->dar));
 				break;
+			}
 
 #if 0
 printf("dsi on addr %x iar %x lr %x\n", frame->dar, frame->srr0,frame->lr);
@@ -388,12 +390,15 @@ printf("dsi on addr %x iar %x lr %x\n", frame->dar, frame->srr0,frame->lr);
 
 			ftype = VM_PROT_READ | VM_PROT_EXECUTE;
 			if (uvm_fault(&p->p_vmspace->vm_map,
-			    trunc_page(frame->srr0), 0, ftype) == 0)
+			    trunc_page(frame->srr0), 0, ftype) == 0) {
+				uvm_grow(p, trunc_page(frame->srr0));
 				break;
+			}
 		}
 #if 0
 printf("isi iar %x lr %x\n", frame->srr0, frame->lr);
 #endif
+		/* FALLTHROUGH */
 	case EXC_MCHK|EXC_USER:
 /* XXX Likely that returning from this trap is bogus... */
 /* XXX Have to make sure that sigreturn does the right thing. */
diff --git a/sys/arch/sparc/sparc/trap.c b/sys/arch/sparc/sparc/trap.c
index dbbc17a2997..ffb05eda902 100644
--- a/sys/arch/sparc/sparc/trap.c
+++ b/sys/arch/sparc/sparc/trap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: trap.c,v 1.41 2004/08/06 22:39:14 deraadt Exp $	*/
+/*	$OpenBSD: trap.c,v 1.42 2004/12/06 20:12:25 miod Exp $	*/
 /*	$NetBSD: trap.c,v 1.58 1997/09/12 08:55:01 pk Exp $ */
 
 /*
@@ -736,11 +736,9 @@ mem_access_fault(type, ser, v, pc, psr, tf)
 	 * error.
 	 */
 	if ((caddr_t)va >= vm->vm_maxsaddr) {
-		if (rv == 0) {
-			unsigned nss = btoc(USRSTACK - va);
-			if (nss > vm->vm_ssize)
-				vm->vm_ssize = nss;
-		} else if (rv == EACCES)
+		if (rv == 0)
+			uvm_grow(p, va);
+		else if (rv == EACCES)
 			rv = EFAULT;
 	}
 	if (rv == 0) {
@@ -972,11 +970,9 @@ mem_access_fault4m(type, sfsr, sfva, tf)
 	 * error.
 	 */
 	if ((caddr_t)va >= vm->vm_maxsaddr) {
-		if (rv == 0) {
-			unsigned nss = btoc(USRSTACK - va);
-			if (nss > vm->vm_ssize)
-				vm->vm_ssize = nss;
-		} else if (rv == EACCES)
+		if (rv == 0)
+			uvm_grow(p, va);
+		else if (rv == EACCES)
 			rv = EFAULT;
 	}
 	if (rv != 0) {
diff --git a/sys/arch/sparc64/sparc64/trap.c b/sys/arch/sparc64/sparc64/trap.c
index b447afb1b64..b7c73f51d41 100644
--- a/sys/arch/sparc64/sparc64/trap.c
+++ b/sys/arch/sparc64/sparc64/trap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: trap.c,v 1.32 2004/08/09 10:13:23 miod Exp $	*/
+/*	$OpenBSD: trap.c,v 1.33 2004/12/06 20:12:25 miod Exp $	*/
 /*	$NetBSD: trap.c,v 1.73 2001/08/09 01:03:01 eeh Exp $ */
 
 /*
@@ -887,11 +887,9 @@ data_access_fault(tf, type, pc, addr, sfva, sfsr)
 	 * error.
 	 */
 	if ((caddr_t)va >= vm->vm_maxsaddr) {
-		if (rv == 0) {
-			segsz_t nss = btoc(USRSTACK - va);
-			if (nss > vm->vm_ssize)
-				vm->vm_ssize = nss;
-		} else if (rv == EACCES)
+		if (rv == 0)
+			uvm_grow(p, va);
+		else if (rv == EACCES)
 			rv = EFAULT;
 	}
 	if (rv != 0) {
@@ -1066,11 +1064,9 @@ text_access_fault(tf, type, pc, sfsr)
 	 * error.
 	 */
 	if ((caddr_t)va >= vm->vm_maxsaddr) {
-		if (rv == 0) {
-			segsz_t nss = btoc(USRSTACK - va);
-			if (nss > vm->vm_ssize)
-				vm->vm_ssize = nss;
-		} else if (rv == EACCES)
+		if (rv == 0)
+			uvm_grow(p, va);
+		else if (rv == EACCES)
 			rv = EFAULT;
 	}
 	if (rv != 0) {
@@ -1173,11 +1169,9 @@ text_access_error(tf, type, pc, sfsr, afva, afsr)
 	 * error.
 	 */
 	if ((caddr_t)va >= vm->vm_maxsaddr) {
-		if (rv == 0) {
-			segsz_t nss = btoc(USRSTACK - va);
-			if (nss > vm->vm_ssize)
-				vm->vm_ssize = nss;
-		} else if (rv == EACCES)
+		if (rv == 0)
+			uvm_grow(p, va);
+		else if (rv == EACCES)
 			rv = EFAULT;
 	}
 	if (rv != 0) {
diff --git a/sys/arch/vax/vax/trap.c b/sys/arch/vax/vax/trap.c
index a95a59d5d0f..7d4caf6e0ae 100644
--- a/sys/arch/vax/vax/trap.c
+++ b/sys/arch/vax/vax/trap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: trap.c,v 1.28 2004/03/09 22:29:01 miod Exp $     */
+/*	$OpenBSD: trap.c,v 1.29 2004/12/06 20:12:25 miod Exp $     */
 /*	$NetBSD: trap.c,v 1.47 1999/08/21 19:26:20 matt Exp $     */
 /*
  * Copyright (c) 1994 Ludd, University of Lule}, Sweden.
@@ -255,8 +255,11 @@ if(faultdebug)printf("trap accflt type %lx, code %lx, pc %lx, psl %lx\n",
 				sig = SIGSEGV;
 				typ = SEGV_MAPERR;
 			}
-		} else
+		} else {
 			trapsig = 0;
+			if (umode != 0)
+				uvm_grow(p, addr);
+		}
 		break;
 
 	case T_PTELEN: