arm64: page-align sections for DEBUG_RODATA
authorMark Rutland <mark.rutland@arm.com>
Mon, 26 Oct 2015 21:42:33 +0000 (21:42 +0000)
committerCatalin Marinas <catalin.marinas@arm.com>
Thu, 29 Oct 2015 17:23:39 +0000 (17:23 +0000)
commitcb083816ab5ac3d10a9417527f07fc5962cc3808
treed829d1b151d207084c5af4e879a09a52f01c2e0f
parent86a5906e4d1df1ec160fa9e18b6f2277a5216c60
arm64: page-align sections for DEBUG_RODATA

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")
Cc: <stable@vger.kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
arch/arm64/kernel/vmlinux.lds.S