From mboxrd@z Thu Jan 1 00:00:00 1970 From: mark.rutland@arm.com (Mark Rutland) Date: Tue, 27 Oct 2015 10:56:33 +0000 Subject: [PATCH] arm64: page-align sections for DEBUG_RODATA In-Reply-To: References: <1445895753-2095-1-git-send-email-mark.rutland@arm.com> Message-ID: <20151027105632.GA3091@leverpostej> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tue, Oct 27, 2015 at 11:37:04AM +0900, Ard Biesheuvel wrote: > On 27 October 2015 at 06:42, Mark Rutland wrote: > > 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 > > Reported-by: Jeremy Linton > > Reviewed-by: Laura Abbott > > Cc: Ard Biesheuvel > > Cc: Catalin Marinas > > Cc: Suzuki Poulose > > Cc: Will Deacon > > --- > > arch/arm64/kernel/vmlinux.lds.S | 5 ++++- > > 1 file changed, 4 insertions(+), 1 deletion(-) > > > > Note: this is intended to supercede [1,2]. > > > > [1] http://lists.infradead.org/pipermail/linux-arm-kernel/2015-October/380486.html > > [2] http://lists.infradead.org/pipermail/linux-arm-kernel/2015-October/380999.html > > > > diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S > > index 9807333..4d77757 100644 > > --- a/arch/arm64/kernel/vmlinux.lds.S > > +++ b/arch/arm64/kernel/vmlinux.lds.S > > @@ -60,9 +60,12 @@ 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< > #define ALIGN_DEBUG_RO_MIN(min) ALIGN_DEBUG_RO > > +#elif defined(CONFIG_DEBUG_RODATA) > > +#define ALIGN_DEBUG_RO . = ALIGN(1< > +#define ALIGN_DEBUG_RO_MIN(min) ALIGN_DEBUG_RO > > #else > > #define ALIGN_DEBUG_RO > > #define ALIGN_DEBUG_RO_MIN(min) . = ALIGN(min); > > Acked-by: Ard Biesheuvel Cheers, Ard. Jeremy, does this work for you? If so, I expect Catalin will take this for 4.4, with the addition of any Acks and: Fixes: da141706aea52c1a ("arm64: add better page protections to arm64") Cc: Thanks, Mark.