linux-kernel - [PATCH 1/4] mm: add is_highmem

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]

Date:	Thu, 31 Mar 2016 14:29:41 +0200
From:	Boris Brezillon <boris.brezillon@...e-electrons.com>
To:	David Woodhouse <dwmw2@...radead.org>,
	Brian Norris <computersforpeace@...il.com>,
	linux-mtd@...ts.infradead.org,
	Andrew Morton <akpm@...ux-foundation.org>,
	Dave Gordon <david.s.gordon@...el.com>
Cc:	Mark Brown <broonie@...nel.org>, linux-spi@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org,
	Vinod Koul <vinod.koul@...el.com>,
	Dan Williams <dan.j.williams@...el.com>,
	dmaengine@...r.kernel.org,
	Mauro Carvalho Chehab <m.chehab@...sung.com>,
	Hans Verkuil <hans.verkuil@...co.com>,
	Laurent Pinchart <laurent.pinchart@...asonboard.com>,
	linux-media@...r.kernel.org,
	Boris Brezillon <boris.brezillon@...e-electrons.com>,
	Richard Weinberger <richard@....at>,
	Herbert Xu <herbert@...dor.apana.org.au>,
	"David S. Miller" <davem@...emloft.net>,
	linux-crypto@...r.kernel.org, Vignesh R <vigneshr@...com>,
	linux-mm@...ck.org, Joerg Roedel <joro@...tes.org>,
	iommu@...ts.linux-foundation.org, linux-kernel@...r.kernel.org
Subject: [PATCH 1/4] mm: add is_highmem_addr() helper

Add an helper to check if a virtual address is in the highmem region.

Signed-off-by: Boris Brezillon <boris.brezillon@...e-electrons.com>
---
 include/linux/highmem.h | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/include/linux/highmem.h b/include/linux/highmem.h
index bb3f329..13dff37 100644
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -41,6 +41,14 @@ void kmap_flush_unused(void);
 
 struct page *kmap_to_page(void *addr);
 
+static inline bool is_highmem_addr(const void *x)
+{
+	unsigned long vaddr = (unsigned long)x;
+
+	return vaddr >=  PKMAP_BASE &&
+	       vaddr < ((PKMAP_BASE + LAST_PKMAP) * PAGE_SIZE);
+}
+
 #else /* CONFIG_HIGHMEM */
 
 static inline unsigned int nr_free_highpages(void) { return 0; }
@@ -50,6 +58,11 @@ static inline struct page *kmap_to_page(void *addr)
 	return virt_to_page(addr);
 }
 
+static inline bool is_highmem_addr(const void *x)
+{
+	return false;
+}
+
 #define totalhigh_pages 0UL
 
 #ifndef ARCH_HAS_KMAP
-- 
2.5.0