From 55ffcab7b6e26b33fcb281aa70dc9abc33aa7ead Mon Sep 17 00:00:00 2001 From: Roland McGrath Date: Sun, 19 Sep 1999 20:40:43 +0000 Subject: * 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. --- ChangeLog | 4 ++++ sysdeps/mach/hurd/brk.c | 15 ++++++++++++--- 2 files changed, 16 insertions(+), 3 deletions(-) diff --git a/ChangeLog b/ChangeLog index 9019d9b..f7a6a6b 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,5 +1,9 @@ 1999-09-19 Roland McGrath + * 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 3a5ed54..c5d09a3 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; } -- cgit v1.1