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
This commit is contained in:
Alan Cox 2012-02-19 00:28:49 +00:00
parent 3e2f30f6dd
commit 7dc0ace10e
Notes: svn2git 2020-12-20 02:59:44 +00:00
svn path=/head/; revision=231904

View File

@ -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;