- Use atomic ops for updating the vmspace's refcnt and exitingcnt.

 - Push down Giant into shmexit().  (Giant is acquired only if the vmspace
   contains shm segments.)
 - Eliminate the acquisition of Giant from proc_rwmem().
 - Reduce the scope of Giant in exit1(), uncovering the destruction of the
   address space.

1 files changed, 2 insertions, 2 deletions

diff --git a/sys/kern/sysv_shm.c b/sys/kern/sysv_shm.c
index 1430942..0b016f1 100644
--- a/sys/kern/sysv_shm.c
+++ b/sys/kern/sysv_shm.c
@@ -822,14 +822,14 @@ shmexit_myhook(struct vmspace *vm)
 	struct shmmap_state *base, *shm;
 	int i;
 
-	GIANT_REQUIRED;
-
 	if ((base = vm->vm_shm) != NULL) {
 		vm->vm_shm = NULL;
+		mtx_lock(&Giant);
 		for (i = 0, shm = base; i < shminfo.shmseg; i++, shm++) {
 			if (shm->shmid != -1)
 				shm_delete_mapping(vm, shm);
 		}
+		mtx_unlock(&Giant);
 		free(base, M_SHM);
 	}
 }