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Date: Fri, 13 Apr 2018 17:41:27 +0400
From: Igor Stoppa <igor.stoppa@...il.com>
To: willy@...radead.org,
	keescook@...omium.org,
	mhocko@...nel.org,
	corbet@....net
Cc: david@...morbit.com,
	rppt@...ux.vnet.ibm.com,
	labbott@...hat.com,
	linux-security-module@...r.kernel.org,
	linux-mm@...ck.org,
	linux-kernel@...r.kernel.org,
	kernel-hardening@...ts.openwall.com,
	Igor Stoppa <igor.stoppa@...wei.com>
Subject: [PATCH 2/6] vmalloc: rename llist field in vmap_area

The vmap_area structure has a field of type struct llist_node, named
purge_list and is used when performing lazy purge of the area.

Such field is left unused during the actual utilization of the
structure.

This patch renames the field to a more generic "area_list", to allow for
utilization outside of the purging phase.

Since the purging happens after the vmap_area is dismissed, its use is
mutually exclusive with any use performed while the area is allocated.

Signed-off-by: Igor Stoppa <igor.stoppa@...wei.com>
---
 include/linux/vmalloc.h | 2 +-
 mm/vmalloc.c            | 6 +++---
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
index 1e5d8c392f15..2d07dfef3cfd 100644
--- a/include/linux/vmalloc.h
+++ b/include/linux/vmalloc.h
@@ -47,7 +47,7 @@ struct vmap_area {
 	unsigned long flags;
 	struct rb_node rb_node;         /* address sorted rbtree */
 	struct list_head list;          /* address sorted list */
-	struct llist_node purge_list;    /* "lazy purge" list */
+	struct llist_node area_list;    /* generic list of areas */
 	struct vm_struct *vm;
 	struct rcu_head rcu_head;
 };
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 61a1ca22b0f6..1bb2233bb262 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -682,7 +682,7 @@ static bool __purge_vmap_area_lazy(unsigned long start, unsigned long end)
 	lockdep_assert_held(&vmap_purge_lock);
 
 	valist = llist_del_all(&vmap_purge_list);
-	llist_for_each_entry(va, valist, purge_list) {
+	llist_for_each_entry(va, valist, area_list) {
 		if (va->va_start < start)
 			start = va->va_start;
 		if (va->va_end > end)
@@ -696,7 +696,7 @@ static bool __purge_vmap_area_lazy(unsigned long start, unsigned long end)
 	flush_tlb_kernel_range(start, end);
 
 	spin_lock(&vmap_area_lock);
-	llist_for_each_entry_safe(va, n_va, valist, purge_list) {
+	llist_for_each_entry_safe(va, n_va, valist, area_list) {
 		int nr = (va->va_end - va->va_start) >> PAGE_SHIFT;
 
 		__free_vmap_area(va);
@@ -743,7 +743,7 @@ static void free_vmap_area_noflush(struct vmap_area *va)
 				    &vmap_lazy_nr);
 
 	/* After this point, we may free va at any time */
-	llist_add(&va->purge_list, &vmap_purge_list);
+	llist_add(&va->area_list, &vmap_purge_list);
 
 	if (unlikely(nr_lazy > lazy_max_pages()))
 		try_purge_vmap_area_lazy();
-- 
2.14.1

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