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arm64: page-align sections for DEBUG_RODATA

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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: da141706ae ("arm64: add better page protections to arm64")
Cc: <stable@vger.kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This commit is contained in:
Mark Rutland 2015-10-26 21:42:33 +00:00 committed by Catalin Marinas
parent 86a5906e4d
commit cb083816ab
1 changed files with 4 additions and 1 deletions
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5
arch/arm64/kernel/vmlinux.lds.S
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@ -61,9 +61,12 @@ 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);