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Message-Id: <20170814125411.22604-4-ard.biesheuvel@linaro.org> Date: Mon, 14 Aug 2017 13:53:44 +0100 From: Ard Biesheuvel <ard.biesheuvel@...aro.org> To: kernel-hardening@...ts.openwall.com Cc: linux-arm-kernel@...ts.infradead.org, Ard Biesheuvel <ard.biesheuvel@...aro.org>, Arnd Bergmann <arnd@...db.de>, Nicolas Pitre <nico@...aro.org>, Russell King <linux@...linux.org.uk>, Kees Cook <keescook@...omium.org>, Thomas Garnier <thgarnie@...gle.com>, Marc Zyngier <marc.zyngier@....com>, Mark Rutland <mark.rutland@....com>, Tony Lindgren <tony@...mide.com>, Matt Fleming <matt@...eblueprint.co.uk>, Dave Martin <dave.martin@....com> Subject: [PATCH 03/30] ARM: head-common.S: use PC-relative insn sequence for __proc_info Replace the open coded PC relative offset calculations with a pair of adr_l invocations. This ensures these quantities are invariant under runtime relocation. Cc: Russell King <linux@...linux.org.uk> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@...aro.org> --- arch/arm/kernel/head-common.S | 22 ++++++-------------- 1 file changed, 6 insertions(+), 16 deletions(-) diff --git a/arch/arm/kernel/head-common.S b/arch/arm/kernel/head-common.S index 8733012d231f..06035488130c 100644 --- a/arch/arm/kernel/head-common.S +++ b/arch/arm/kernel/head-common.S @@ -150,11 +150,12 @@ ENDPROC(lookup_processor_type) * r9 = cpuid (preserved) */ __lookup_processor_type: - adr r3, __lookup_processor_type_data - ldmia r3, {r4 - r6} - sub r3, r3, r4 @ get offset between virt&phys - add r5, r5, r3 @ convert virt addresses to - add r6, r6, r3 @ physical address space + /* + * Look in <asm/procinfo.h> for information about the __proc_info + * structure. + */ + adr_l r5, __proc_info_begin + adr_l r6, __proc_info_end 1: ldmia r5, {r3, r4} @ value, mask and r4, r4, r9 @ mask wanted bits teq r3, r4 @@ -166,17 +167,6 @@ __lookup_processor_type: 2: ret lr ENDPROC(__lookup_processor_type) -/* - * Look in <asm/procinfo.h> for information about the __proc_info structure. - */ - .align 2 - .type __lookup_processor_type_data, %object -__lookup_processor_type_data: - .long . - .long __proc_info_begin - .long __proc_info_end - .size __lookup_processor_type_data, . - __lookup_processor_type_data - __error_lpae: #ifdef CONFIG_DEBUG_LL adr r0, str_lpae -- 2.11.0
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