From 7dc0ace10ef83f71cbb1a635be9e3e2ef53b9072 Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Sun, 19 Feb 2012 00:28:49 +0000 Subject: [PATCH] Close a race due to dropping of the map lock between creating a map entry for a shared mapping and marking the entry for inheritance. Reviewed by: kib X-MFC after: r231526 --- sys/kern/sysv_shm.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/sys/kern/sysv_shm.c b/sys/kern/sysv_shm.c index c717c0d9675..5c3551413c9 100644 --- a/sys/kern/sysv_shm.c +++ b/sys/kern/sysv_shm.c @@ -413,14 +413,12 @@ kern_shmat(td, shmid, shmaddr, shmflg) vm_object_reference(shmseg->object); rv = vm_map_find(&p->p_vmspace->vm_map, shmseg->object, 0, &attach_va, size, (flags & MAP_FIXED) ? VMFS_NO_SPACE : - VMFS_ANY_SPACE, prot, prot, 0); + VMFS_ANY_SPACE, prot, prot, MAP_INHERIT_SHARE); if (rv != KERN_SUCCESS) { vm_object_deallocate(shmseg->object); error = ENOMEM; goto done2; } - vm_map_inherit(&p->p_vmspace->vm_map, - attach_va, attach_va + size, VM_INHERIT_SHARE); shmmap_s->va = attach_va; shmmap_s->shmid = shmid;