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-rw-r--r--ChangeLog4
-rw-r--r--sysdeps/mach/hurd/brk.c15
2 files changed, 16 insertions, 3 deletions
diff --git a/ChangeLog b/ChangeLog
index 9019d9b2ab..f7a6a6b003 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,9 @@
1999-09-19 Roland McGrath <roland@baalperazim.frob.com>
+ * sysdeps/mach/hurd/brk.c (_hurd_set_brk): Deallocate and reallocate
+ pages rather than just reprotecting them. This way we don't hold on
+ to the backing space.
+
* hurd/hurdprio.c (_hurd_priority_which_map): Rearrange the code a bit.
Use __munmap instead of __vm_deallocate.
diff --git a/sysdeps/mach/hurd/brk.c b/sysdeps/mach/hurd/brk.c
index 3a5ed54247..c5d09a35ac 100644
--- a/sysdeps/mach/hurd/brk.c
+++ b/sysdeps/mach/hurd/brk.c
@@ -72,9 +72,18 @@ _hurd_set_brk (vm_address_t addr)
if (pagend <= pagebrk)
{
if (pagend < pagebrk)
- /* Make that memory inaccessible. */
- __vm_protect (__mach_task_self (), pagend, pagebrk - pagend,
- 0, VM_PROT_NONE);
+ {
+ /* XXX wish this were atomic... */
+ /* First deallocate the memory to release its backing space. */
+ __vm_deallocate (__mach_task_self (), pagend, pagebrk - pagend);
+ /* Now reallocate it with no access allowed. */
+ err = __vm_map (__mach_task_self (),
+ &pagend, _hurd_data_end - pagend,
+ 0, 0, MACH_PORT_NULL, 0, 0,
+ 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE,
+ VM_INHERIT_COPY);
+ /* XXX what if error? */
+ }
_hurd_brk = addr;
return 0;
}