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From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
To: kernel-hardening@lists.openwall.com
Cc: linux-arm-kernel@lists.infradead.org,
	Ard Biesheuvel <ard.biesheuvel@linaro.org>,
	Arnd Bergmann <arnd@arndb.de>, Nicolas Pitre <nico@linaro.org>,
	Russell King <linux@armlinux.org.uk>,
	Kees Cook <keescook@chromium.org>,
	Thomas Garnier <thgarnie@google.com>,
	Marc Zyngier <marc.zyngier@arm.com>,
	Mark Rutland <mark.rutland@arm.com>,
	Tony Lindgren <tony@atomide.com>,
	Matt Fleming <matt@codeblueprint.co.uk>,
	Dave Martin <dave.martin@arm.com>
Subject: [kernel-hardening] [PATCH 03/30] ARM: head-common.S: use PC-relative insn sequence for __proc_info
Date: Mon, 14 Aug 2017 13:53:44 +0100
Message-ID: <20170814125411.22604-4-ard.biesheuvel@linaro.org> (raw)
In-Reply-To: <20170814125411.22604-1-ard.biesheuvel@linaro.org>

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@armlinux.org.uk>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.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

  parent reply index

Thread overview: 60+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-08-14 12:53 [kernel-hardening] [PATCH 00/30] implement KASLR for ARM Ard Biesheuvel
2017-08-14 12:53 ` [kernel-hardening] [PATCH 01/30] asm-generic: add .data.rel.ro sections to __ro_after_init Ard Biesheuvel
2017-08-14 14:26   ` [kernel-hardening] " Arnd Bergmann
2017-08-14 12:53 ` [kernel-hardening] [PATCH 02/30] ARM: assembler: introduce adr_l, ldr_l and str_l macros Ard Biesheuvel
2017-08-14 15:29   ` [kernel-hardening] " Dave Martin
2017-08-14 15:38     ` Ard Biesheuvel
2017-08-14 15:50       ` Dave Martin
2017-08-14 16:18         ` Nicolas Pitre
2017-08-14 16:22           ` Ard Biesheuvel
2017-08-14 16:33             ` Nicolas Pitre
2017-08-14 16:42             ` Russell King - ARM Linux
2017-08-14 16:56               ` Ard Biesheuvel
2017-08-14 15:32   ` Dave Martin
2017-08-14 15:40     ` Ard Biesheuvel
2017-08-14 15:53       ` Dave Martin
2017-08-14 12:53 ` Ard Biesheuvel [this message]
2017-08-14 12:53 ` [kernel-hardening] [PATCH 04/30] ARM: head-common.S: use PC-relative insn sequence for idmap creation Ard Biesheuvel
2017-08-14 12:53 ` [kernel-hardening] [PATCH 05/30] ARM: head.S: use PC-relative insn sequence for secondary_data Ard Biesheuvel
2017-08-14 12:53 ` [kernel-hardening] [PATCH 06/30] ARM: kernel: use relative references for UP/SMP alternatives Ard Biesheuvel
2017-08-14 12:53 ` [kernel-hardening] [PATCH 07/30] ARM: head: use PC-relative insn sequence for __smp_alt Ard Biesheuvel
2017-08-14 12:53 ` [kernel-hardening] [PATCH 08/30] ARM: sleep.S: use PC-relative insn sequence for sleep_save_sp/mpidr_hash Ard Biesheuvel
2017-08-14 12:53 ` [kernel-hardening] [PATCH 09/30] ARM: head.S: use PC-relative insn sequences for __fixup_pv_table Ard Biesheuvel
2017-08-14 12:53 ` [kernel-hardening] [PATCH 10/30] ARM: head.S: use PC relative insn sequence to calculate PHYS_OFFSET Ard Biesheuvel
2017-08-14 12:53 ` [kernel-hardening] [PATCH 11/30] ARM: kvm: replace open coded VA->PA calculations with adr_l call Ard Biesheuvel
2017-08-14 12:53 ` [kernel-hardening] [PATCH 12/30] arm-soc: exynos: replace open coded VA->PA conversions Ard Biesheuvel
2017-08-14 12:53 ` [kernel-hardening] [PATCH 13/30] arm-soc: mvebu: replace open coded VA->PA conversion Ard Biesheuvel
2017-08-14 12:53 ` [kernel-hardening] [PATCH 14/30] arm-soc: various: replace open coded VA->PA calculation of pen_release Ard Biesheuvel
2017-08-14 12:53 ` [kernel-hardening] [PATCH 15/30] ARM: kernel: switch to relative exception tables Ard Biesheuvel
2017-08-14 12:53 ` [kernel-hardening] [PATCH 16/30] ARM: kernel: use relative phys-to-virt patch tables Ard Biesheuvel
2017-08-14 12:53 ` [kernel-hardening] [PATCH 17/30] arm-soc: tegra: make sleep asm code runtime relocatable Ard Biesheuvel
2017-08-14 14:42   ` [kernel-hardening] " Dave Martin
2017-08-14 14:49     ` Ard Biesheuvel
2017-08-14 15:29       ` Dave Martin
2017-08-14 12:53 ` [kernel-hardening] [PATCH 18/30] ARM: kernel: make vmlinux buildable as a PIE executable Ard Biesheuvel
2017-08-14 12:54 ` [kernel-hardening] [PATCH 19/30] ARM: kernel: use PC-relative symbol references in MMU switch code Ard Biesheuvel
2017-08-14 12:54 ` [kernel-hardening] [PATCH 20/30] ARM: kernel: use PC relative symbol references in suspend/resume code Ard Biesheuvel
2017-08-14 16:02   ` [kernel-hardening] " Nicolas Pitre
2017-08-14 18:14     ` Ard Biesheuvel
2017-08-14 18:37       ` Nicolas Pitre
2017-08-14 12:54 ` [kernel-hardening] [PATCH 21/30] ARM: mm: export default vmalloc base address Ard Biesheuvel
2017-08-14 12:54 ` [kernel-hardening] [PATCH 22/30] ARM: kernel: refer to swapper_pg_dir via its symbol Ard Biesheuvel
2017-08-14 12:54 ` [kernel-hardening] [PATCH 23/30] ARM: kernel: implement randomization of the kernel load address Ard Biesheuvel
2017-08-14 12:54 ` [kernel-hardening] [PATCH 24/30] ARM: decompressor: explicitly map decompressor binary cacheable Ard Biesheuvel
2017-08-14 12:54 ` [kernel-hardening] [PATCH 25/30] ARM: compressed: factor out zImage header and make it extensible Ard Biesheuvel
2017-08-14 12:54 ` [kernel-hardening] [PATCH 26/30] ARM: decompressor: add KASLR support Ard Biesheuvel
2017-08-14 12:54 ` [kernel-hardening] [PATCH 27/30] efi/libstub: add 'max' parameter to efi_random_alloc() Ard Biesheuvel
2017-08-14 12:54 ` [kernel-hardening] [PATCH 28/30] efi/libstub: check for vmalloc= command line argument Ard Biesheuvel
2017-08-14 12:54 ` [kernel-hardening] [PATCH 29/30] efi/libstub: arm: reserve bootloader supplied initrd in memory map Ard Biesheuvel
2017-08-18 11:48   ` [kernel-hardening] " Ard Biesheuvel
2017-08-21 10:37   ` Mark Rutland
2017-08-21 10:39     ` Ard Biesheuvel
2017-08-14 12:54 ` [kernel-hardening] [PATCH 30/30] efi/libstub: arm: implement KASLR Ard Biesheuvel
2017-08-14 15:30 ` [kernel-hardening] Re: [PATCH 00/30] implement KASLR for ARM Arnd Bergmann
2017-08-14 15:49   ` Ard Biesheuvel
2017-08-14 16:03     ` Arnd Bergmann
2017-08-14 16:28       ` Nicolas Pitre
2017-08-14 17:28         ` Ard Biesheuvel
2017-08-14 18:01           ` Nicolas Pitre
2017-08-14 18:08             ` Ard Biesheuvel
2017-08-14 16:16     ` Nicolas Pitre

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