arm64: page-align sections for DEBUG_RODATA
authorMark Rutland <mark.rutland@arm.com>
Mon, 26 Oct 2015 21:42:33 +0000 (21:42 +0000)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 9 Dec 2015 19:03:22 +0000 (14:03 -0500)
commitd3a80fbec20ffa27f71295d24ce456934ad8c7a7
tree999e1dc69ef30f67f600c1047ddd1163916bb3b9
parenta95468b014b7389e858b847449bb56cb7c4857a4
arm64: page-align sections for DEBUG_RODATA

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 <mark.rutland@arm.com>
Reported-by: Jeremy Linton <jeremy.linton@arm.com>
Reviewed-by: Laura Abbott <laura@labbott.name>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Suzuki Poulose <suzuki.poulose@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Fixes: da141706aea52c1a ("arm64: add better page protections to arm64")
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arch/arm64/kernel/vmlinux.lds.S