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

1 changed files with 1 additions and 3 deletions

									
										sys/kern/sysv_shm.c
									
		+1
		-3
	
												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;