1 /* SPDX-License-Identifier: GPL-2.0 */
18  * mmgrab() - Pin a &struct mm_struct.
31  * See also <Documentation/vm/active_mm.rst> for an in-depth explanation
36 	atomic_inc(&mm->mm_count);  in mmgrab()
46 	 * user-space, after storing to rq->curr.  in mmdrop()
48 	if (unlikely(atomic_dec_and_test(&mm->mm_count)))  in mmdrop()
53  * mmget() - Pin the address space associated with a &struct mm_struct.
57  * go away. This does not protect against parts of the address space being
65  * See also <Documentation/vm/active_mm.rst> for an in-depth explanation
70 	atomic_inc(&mm->mm_users);  in mmget()
75 	return atomic_inc_not_zero(&mm->mm_users);  in mmget_not_zero()
78 /* mmput gets rid of the mappings and all user-space */
97 /* Remove the current tasks stale references to the old mm_struct on exec() */
136 	 * need RCU to access ->real_parent if CLONE_VM was used along with  in in_vfork()
139 	 * We check real_parent->mm == tsk->mm because CLONE_VFORK does not  in in_vfork()
143 	 * ->real_parent is not necessarily the task doing vfork(), so in  in in_vfork()
146 	 * And in this case we can't trust the real_parent->mm == tsk->mm  in in_vfork()
148 	 * another oom-unkillable task does this it should blame itself.  in in_vfork()
151 	ret = tsk->vfork_done &&  in in_vfork()
152 			rcu_dereference(tsk->real_parent)->mm == tsk->mm;  in in_vfork()
159  * Applies per-task gfp context to the given allocation flags.
165 	unsigned int pflags = READ_ONCE(current->flags);  in current_gfp_context()
193  * memalloc_noio_save - Marks implicit GFP_NOIO allocation scope.
205 	unsigned int flags = current->flags & PF_MEMALLOC_NOIO;  in memalloc_noio_save()
206 	current->flags |= PF_MEMALLOC_NOIO;  in memalloc_noio_save()
211  * memalloc_noio_restore - Ends the implicit GFP_NOIO scope.
220 	current->flags = (current->flags & ~PF_MEMALLOC_NOIO) | flags;  in memalloc_noio_restore()
224  * memalloc_nofs_save - Marks implicit GFP_NOFS allocation scope.
236 	unsigned int flags = current->flags & PF_MEMALLOC_NOFS;  in memalloc_nofs_save()
237 	current->flags |= PF_MEMALLOC_NOFS;  in memalloc_nofs_save()
242  * memalloc_nofs_restore - Ends the implicit GFP_NOFS scope.
251 	current->flags = (current->flags & ~PF_MEMALLOC_NOFS) | flags;  in memalloc_nofs_restore()
256 	unsigned int flags = current->flags & PF_MEMALLOC;  in memalloc_noreclaim_save()
257 	current->flags |= PF_MEMALLOC;  in memalloc_noreclaim_save()
263 	current->flags = (current->flags & ~PF_MEMALLOC) | flags;  in memalloc_noreclaim_restore()
269 	unsigned int flags = current->flags & PF_MEMALLOC_NOCMA;  in memalloc_nocma_save()
271 	current->flags |= PF_MEMALLOC_NOCMA;  in memalloc_nocma_save()
277 	current->flags = (current->flags & ~PF_MEMALLOC_NOCMA) | flags;  in memalloc_nocma_restore()
293  * set_active_memcg - Starts the remote memcg charging scope.
312 		old = current->active_memcg;  in set_active_memcg()
313 		current->active_memcg = memcg;  in set_active_memcg()
349 	if (current->mm != mm)  in membarrier_mm_sync_core_before_usermode()
351 	if (likely(!(atomic_read(&mm->membarrier_state) &  in membarrier_mm_sync_core_before_usermode()