Patchwork [3.5.y.z,extended,stable] Patch "ARM: mm: use pteval_t to represent page protection values" has been added to staging queue

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Submitter Herton Ronaldo Krzesinski
Date Jan. 7, 2013, 8:32 p.m.
Message ID <1357590768-17305-1-git-send-email-herton.krzesinski@canonical.com>
Download mbox | patch
Permalink /patch/210130/
State New
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Comments

Herton Ronaldo Krzesinski - Jan. 7, 2013, 8:32 p.m.
This is a note to let you know that I have just added a patch titled

    ARM: mm: use pteval_t to represent page protection values

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Herton

------

From 13ac68b6e584eaf69d57e62045e8331a60edeca2 Mon Sep 17 00:00:00 2001
From: Will Deacon <will.deacon@arm.com>
Date: Tue, 18 Sep 2012 19:18:35 +0100
Subject: [PATCH] ARM: mm: use pteval_t to represent page protection values

commit 864aa04cd02979c2c755cb28b5f4fe56039171c0 upstream.

When updating the page protection map after calculating the user_pgprot
value, the base protection map is temporarily stored in an unsigned long
type, causing truncation of the protection bits when LPAE is enabled.
This effectively means that calls to mprotect() will corrupt the upper
page attributes, clearing the XN bit unconditionally.

This patch uses pteval_t to store the intermediate protection values,
preserving the upper bits for 64-bit descriptors.

Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com>
---
 arch/arm/mm/mmu.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--
1.7.9.5

Patch

diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index 15c6abe..f117e1f 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -504,7 +504,7 @@  static void __init build_mem_type_table(void)
 #endif

 	for (i = 0; i < 16; i++) {
-		unsigned long v = pgprot_val(protection_map[i]);
+		pteval_t v = pgprot_val(protection_map[i]);
 		protection_map[i] = __pgprot(v | user_pgprot);
 	}