Use the fields in the sysentvec and in the vm map header in place of the

constants VM_MIN_ADDRESS, VM_MAXUSER_ADDRESS, USRSTACK and PS_STRINGS.
This is mainly so that they can be variable even for the native abi, based
on different machine types.  Get stack protections from the sysentvec too.
This makes it trivial to map the stack non-executable for certain abis, on
machines that support it.

1 files changed, 6 insertions, 3 deletions

diff --git a/sys/kern/kern_resource.c b/sys/kern/kern_resource.c
index 8f02c13..535756c 100644
--- a/sys/kern/kern_resource.c
+++ b/sys/kern/kern_resource.c
@@ -52,6 +52,7 @@
 #include <sys/proc.h>
 #include <sys/resourcevar.h>
 #include <sys/sx.h>
+#include <sys/sysent.h>
 #include <sys/time.h>
 
 #include <vm/vm.h>
@@ -593,13 +594,15 @@ dosetrlimit(td, which, limp)
 			vm_prot_t prot;
 
 			if (limp->rlim_cur > alimp->rlim_cur) {
-				prot = VM_PROT_ALL;
+				prot = p->p_sysent->sv_stackprot;
 				size = limp->rlim_cur - alimp->rlim_cur;
-				addr = USRSTACK - limp->rlim_cur;
+				addr = p->p_sysent->sv_usrstack -
+				    limp->rlim_cur;
 			} else {
 				prot = VM_PROT_NONE;
 				size = alimp->rlim_cur - limp->rlim_cur;
-				addr = USRSTACK - alimp->rlim_cur;
+				addr = p->p_sysent->sv_usrstack -
+				    alimp->rlim_cur;
 			}
 			addr = trunc_page(addr);
 			size = round_page(size);