linux-kernel - [PATCH v27 3/4] mm/page_poison: expose page_poisoning

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1517986471-15185-4-git-send-email-wei.w.wang@intel.com>
Date:   Wed,  7 Feb 2018 14:54:30 +0800
From:   Wei Wang <wei.w.wang@...el.com>
To:     virtio-dev@...ts.oasis-open.org, linux-kernel@...r.kernel.org,
        virtualization@...ts.linux-foundation.org, kvm@...r.kernel.org,
        linux-mm@...ck.org, mst@...hat.com, mhocko@...nel.org,
        akpm@...ux-foundation.org
Cc:     pbonzini@...hat.com, wei.w.wang@...el.com,
        liliang.opensource@...il.com, yang.zhang.wz@...il.com,
        quan.xu0@...il.com, nilal@...hat.com, riel@...hat.com,
        huangzhichao@...wei.com
Subject: [PATCH v27 3/4] mm/page_poison: expose page_poisoning_enabled to kernel modules

In some usages, e.g. virtio-balloon, a kernel module needs to know if
page poisoning is in use. This patch exposes the page_poisoning_enabled
function to kernel modules.

Signed-off-by: Wei Wang <wei.w.wang@...el.com>
Cc: Andrew Morton <akpm@...ux-foundation.org>
Cc: Michal Hocko <mhocko@...nel.org>
Cc: Michael S. Tsirkin <mst@...hat.com>
---
 mm/page_poison.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/mm/page_poison.c b/mm/page_poison.c
index e83fd44..c08d02a 100644
--- a/mm/page_poison.c
+++ b/mm/page_poison.c
@@ -30,6 +30,11 @@ bool page_poisoning_enabled(void)
 		debug_pagealloc_enabled()));
 }
 
+/**
+ * page_poisoning_enabled - check if page poisoning is enabled
+ *
+ * Return true if page poisoning is enabled, or false if not.
+ */
 static void poison_page(struct page *page)
 {
 	void *addr = kmap_atomic(page);
@@ -37,6 +42,7 @@ static void poison_page(struct page *page)
 	memset(addr, PAGE_POISON, PAGE_SIZE);
 	kunmap_atomic(addr);
 }
+EXPORT_SYMBOL_GPL(page_poisoning_enabled);
 
 static void poison_pages(struct page *page, int n)
 {
-- 
2.7.4