From: Steve Capper <steve.capper@linaro.org>
To: linux-mm@kvack.org, x86@kernel.org, linux-arch@vger.kernel.org,
linux-arm-kernel@lists.infradead.org
Cc: Michal Hocko <mhocko@suse.cz>, Ken Chen <kenchen@google.com>,
Mel Gorman <mgorman@suse.de>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will.deacon@arm.com>,
patches@linaro.org, Steve Capper <steve.capper@linaro.org>
Subject: [RFC PATCH v2 07/11] ARM64: mm: Make PAGE_NONE pages read only and no-execute.
Date: Wed, 8 May 2013 10:52:39 +0100 [thread overview]
Message-ID: <1368006763-30774-8-git-send-email-steve.capper@linaro.org> (raw)
In-Reply-To: <1368006763-30774-1-git-send-email-steve.capper@linaro.org>
If we consider the following code sequence:
my_pte = pte_modify(entry, myprot);
x = pte_write(my_pte);
y = pte_exec(my_pte);
If myprot comes from a PROT_NONE page, then x and y will both be
true which is undesireable behaviour.
This patch sets the no-execute and read-only bits for PAGE_NONE
such that the code above will return false for both x and y.
Signed-off-by: Steve Capper <steve.capper@linaro.org>
---
arch/arm64/include/asm/pgtable.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index e333a24..b1a1b59 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -66,7 +66,7 @@ extern pgprot_t pgprot_default;
#define _MOD_PROT(p, b) __pgprot_modify(p, 0, b)
-#define PAGE_NONE __pgprot_modify(pgprot_default, PTE_TYPE_MASK, PTE_PROT_NONE)
+#define PAGE_NONE __pgprot_modify(pgprot_default, PTE_TYPE_MASK, PTE_PROT_NONE | PTE_RDONLY | PTE_UXN)
#define PAGE_SHARED _MOD_PROT(pgprot_default, PTE_USER | PTE_NG | PTE_PXN | PTE_UXN)
#define PAGE_SHARED_EXEC _MOD_PROT(pgprot_default, PTE_USER | PTE_NG | PTE_PXN)
#define PAGE_COPY _MOD_PROT(pgprot_default, PTE_USER | PTE_NG | PTE_PXN | PTE_UXN | PTE_RDONLY)
@@ -76,7 +76,7 @@ extern pgprot_t pgprot_default;
#define PAGE_KERNEL _MOD_PROT(pgprot_default, PTE_PXN | PTE_UXN | PTE_DIRTY)
#define PAGE_KERNEL_EXEC _MOD_PROT(pgprot_default, PTE_UXN | PTE_DIRTY)
-#define __PAGE_NONE __pgprot(((_PAGE_DEFAULT) & ~PTE_TYPE_MASK) | PTE_PROT_NONE)
+#define __PAGE_NONE __pgprot(((_PAGE_DEFAULT) & ~PTE_TYPE_MASK) | PTE_PROT_NONE | PTE_RDONLY | PTE_UXN)
#define __PAGE_SHARED __pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN | PTE_UXN)
#define __PAGE_SHARED_EXEC __pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN)
#define __PAGE_COPY __pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN | PTE_UXN | PTE_RDONLY)
--
1.8.1.4
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2013-05-08 9:53 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-05-08 9:52 [RFC PATCH v2 00/11] HugeTLB and THP support for ARM64 Steve Capper
2013-05-08 9:52 ` [RFC PATCH v2 01/11] mm: hugetlb: Copy huge_pmd_share from x86 to mm Steve Capper
2013-05-08 9:52 ` [RFC PATCH v2 02/11] x86: mm: Remove x86 version of huge_pmd_share Steve Capper
2013-05-08 9:52 ` [RFC PATCH v2 03/11] mm: hugetlb: Copy general hugetlb code from x86 to mm Steve Capper
2013-05-08 9:52 ` [RFC PATCH v2 04/11] x86: mm: Remove general hugetlb code from x86 Steve Capper
2013-05-08 9:52 ` [RFC PATCH v2 05/11] mm: thp: Correct the HPAGE_PMD_ORDER check Steve Capper
2013-05-08 12:44 ` Kirill A. Shutemov
2013-05-08 12:03 ` Steve Capper
2013-05-08 9:52 ` [RFC PATCH v2 06/11] ARM64: mm: Restore memblock limit when map_mem finished Steve Capper
2013-05-16 13:52 ` Catalin Marinas
2013-05-08 9:52 ` Steve Capper [this message]
2013-05-08 16:43 ` [RFC PATCH v2 07/11] ARM64: mm: Make PAGE_NONE pages read only and no-execute Will Deacon
2013-05-09 8:27 ` Steve Capper
2013-05-08 9:52 ` [RFC PATCH v2 08/11] ARM64: mm: Swap PTE_FILE and PTE_PROT_NONE bits Steve Capper
2013-05-08 16:17 ` Christopher Covington
2013-05-09 8:15 ` Steve Capper
2013-05-08 16:40 ` Will Deacon
2013-05-09 8:22 ` Steve Capper
2013-05-16 14:58 ` Catalin Marinas
2013-05-08 9:52 ` [RFC PATCH v2 09/11] ARM64: mm: HugeTLB support Steve Capper
2013-05-16 14:32 ` Catalin Marinas
2013-05-17 8:41 ` Steve Capper
2013-05-08 9:52 ` [RFC PATCH v2 10/11] ARM64: mm: Raise MAX_ORDER for 64KB pages and THP Steve Capper
2013-05-16 14:59 ` Catalin Marinas
2013-05-08 9:52 ` [RFC PATCH v2 11/11] ARM64: mm: THP support Steve Capper
2013-05-16 15:01 ` Catalin Marinas
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1368006763-30774-8-git-send-email-steve.capper@linaro.org \
--to=steve.capper@linaro.org \
--cc=catalin.marinas@arm.com \
--cc=kenchen@google.com \
--cc=linux-arch@vger.kernel.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-mm@kvack.org \
--cc=mgorman@suse.de \
--cc=mhocko@suse.cz \
--cc=patches@linaro.org \
--cc=will.deacon@arm.com \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).