Patch "arm64: page-align sections for DEBUG_RODATA" has been added to the 4.1-stable tree

PATCH [email protected] 1 participant 1 message Dec 7, 2015

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Stable branch arm64

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2015-12-07 12:12 UTC #0 lore raw

This is a note to let you know that I've just added the patch titled

arm64: page-align sections for DEBUG_RODATA

to the 4.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
arm64-page-align-sections-for-debug_rodata.patch
and it can be found in the queue-4.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

Quoted 1 line

From cb083816ab5ac3d10a9417527f07fc5962cc3808 Mon Sep 17 00:00:00 2001

From: Mark Rutland <[email protected]>
Date: Mon, 26 Oct 2015 21:42:33 +0000
Subject: arm64: page-align sections for DEBUG_RODATA

From: Mark Rutland <[email protected]>

commit cb083816ab5ac3d10a9417527f07fc5962cc3808 upstream.

A kernel built with DEBUG_RO_DATA && !CONFIG_DEBUG_ALIGN_RODATA doesn't have .text aligned to a page boundary, though fixup_executable works at page-granularity thanks to its use of create_mapping. If .text is not page-aligned, the first page it exists in may be marked non-executable, leading to failures when an attempt is made to execute code in said page.

This patch upgrades ALIGN_DEBUG_RO and ALIGN_DEBUG_RO_MIN to force page alignment for DEBUG_RO_DATA && !CONFIG_DEBUG_ALIGN_RODATA kernels, ensuring that all sections with specific RWX permission requirements are mapped with the correct permissions.

Signed-off-by Mark Rutland <[email protected]>

Reported-by Jeremy Linton <[email protected]>

Reviewed-by Laura Abbott <[email protected]>

Acked-by Ard Biesheuvel <[email protected]>

Cc Suzuki Poulose <[email protected]>

Cc Will Deacon <[email protected]>

Fixes da141706aea52c1a ("arm64: add better page protections to arm64")

Signed-off-by Catalin Marinas <[email protected]>

Signed-off-by Greg Kroah-Hartman <[email protected]>

---
 arch/arm64/kernel/vmlinux.lds.S |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

arch/arm64/kernel/vmlinux.lds.S +4 -1

@@ -54,9 +54,12 @@ PECOFF_FILE_ALIGNMENT = 0x200;
 #define PECOFF_EDATA_PADDING
 #endif
 
-#ifdef CONFIG_DEBUG_ALIGN_RODATA
+#if defined(CONFIG_DEBUG_ALIGN_RODATA)
 #define ALIGN_DEBUG_RO			. = ALIGN(1<<SECTION_SHIFT);
 #define ALIGN_DEBUG_RO_MIN(min)		ALIGN_DEBUG_RO
+#elif defined(CONFIG_DEBUG_RODATA)
+#define ALIGN_DEBUG_RO			. = ALIGN(1<<PAGE_SHIFT);
+#define ALIGN_DEBUG_RO_MIN(min)		ALIGN_DEBUG_RO
 #else
 #define ALIGN_DEBUG_RO
 #define ALIGN_DEBUG_RO_MIN(min)		. = ALIGN(min);

Patches currently in stable-queue which might be from [email protected] are

queue-4.1/arm64-page-align-sections-for-debug_rodata.patch