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From: ard.biesheuvel@linaro.org (Ard Biesheuvel)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 05/30] ARM: head.S: use PC-relative insn sequence for secondary_data
Date: Mon, 14 Aug 2017 13:53:46 +0100	[thread overview]
Message-ID: <20170814125411.22604-6-ard.biesheuvel@linaro.org> (raw)
In-Reply-To: <20170814125411.22604-1-ard.biesheuvel@linaro.org>

Replace the open coded PC relative offset calculations with adr_l
and ldr_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.S | 19 ++++---------------
 1 file changed, 4 insertions(+), 15 deletions(-)

diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S
index 0a98aec0e39d..6e9df3663a57 100644
--- a/arch/arm/kernel/head.S
+++ b/arch/arm/kernel/head.S
@@ -386,10 +386,8 @@ ENTRY(secondary_startup)
 	/*
 	 * Use the page tables supplied from  __cpu_up.
 	 */
-	adr	r4, __secondary_data
-	ldmia	r4, {r5, r7, r12}		@ address to jump to after
-	sub	lr, r4, r5			@ mmu has been enabled
-	add	r3, r7, lr
+	adr_l	r3, secondary_data
+	mov_l	r12, __secondary_switched
 	ldrd	r4, [r3, #0]			@ get secondary_data.pgdir
 ARM_BE8(eor	r4, r4, r5)			@ Swap r5 and r4 in BE:
 ARM_BE8(eor	r5, r4, r5)			@ it can be done in 3 steps
@@ -404,22 +402,13 @@ ARM_BE8(eor	r4, r4, r5)			@ without using a temp reg.
 ENDPROC(secondary_startup)
 ENDPROC(secondary_startup_arm)
 
-	/*
-	 * r6  = &secondary_data
-	 */
 ENTRY(__secondary_switched)
-	ldr	sp, [r7, #12]			@ get secondary_data.stack
+	ldr_l	r7, secondary_data + 12		@ get secondary_data.stack
+	mov	sp, r7
 	mov	fp, #0
 	b	secondary_start_kernel
 ENDPROC(__secondary_switched)
 
-	.align
-
-	.type	__secondary_data, %object
-__secondary_data:
-	.long	.
-	.long	secondary_data
-	.long	__secondary_switched
 #endif /* defined(CONFIG_SMP) */
 
 
-- 
2.11.0

WARNING: multiple messages have this Message-ID (diff)
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 05/30] ARM: head.S: use PC-relative insn sequence for secondary_data
Date: Mon, 14 Aug 2017 13:53:46 +0100	[thread overview]
Message-ID: <20170814125411.22604-6-ard.biesheuvel@linaro.org> (raw)
In-Reply-To: <20170814125411.22604-1-ard.biesheuvel@linaro.org>

Replace the open coded PC relative offset calculations with adr_l
and ldr_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.S | 19 ++++---------------
 1 file changed, 4 insertions(+), 15 deletions(-)

diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S
index 0a98aec0e39d..6e9df3663a57 100644
--- a/arch/arm/kernel/head.S
+++ b/arch/arm/kernel/head.S
@@ -386,10 +386,8 @@ ENTRY(secondary_startup)
 	/*
 	 * Use the page tables supplied from  __cpu_up.
 	 */
-	adr	r4, __secondary_data
-	ldmia	r4, {r5, r7, r12}		@ address to jump to after
-	sub	lr, r4, r5			@ mmu has been enabled
-	add	r3, r7, lr
+	adr_l	r3, secondary_data
+	mov_l	r12, __secondary_switched
 	ldrd	r4, [r3, #0]			@ get secondary_data.pgdir
 ARM_BE8(eor	r4, r4, r5)			@ Swap r5 and r4 in BE:
 ARM_BE8(eor	r5, r4, r5)			@ it can be done in 3 steps
@@ -404,22 +402,13 @@ ARM_BE8(eor	r4, r4, r5)			@ without using a temp reg.
 ENDPROC(secondary_startup)
 ENDPROC(secondary_startup_arm)
 
-	/*
-	 * r6  = &secondary_data
-	 */
 ENTRY(__secondary_switched)
-	ldr	sp, [r7, #12]			@ get secondary_data.stack
+	ldr_l	r7, secondary_data + 12		@ get secondary_data.stack
+	mov	sp, r7
 	mov	fp, #0
 	b	secondary_start_kernel
 ENDPROC(__secondary_switched)
 
-	.align
-
-	.type	__secondary_data, %object
-__secondary_data:
-	.long	.
-	.long	secondary_data
-	.long	__secondary_switched
 #endif /* defined(CONFIG_SMP) */
 
 
-- 
2.11.0

  parent reply	other threads:[~2017-08-14 12:53 UTC|newest]

Thread overview: 120+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-08-14 12:53 [PATCH 00/30] implement KASLR for ARM Ard Biesheuvel
2017-08-14 12:53 ` [kernel-hardening] " Ard Biesheuvel
2017-08-14 12:53 ` [PATCH 01/30] asm-generic: add .data.rel.ro sections to __ro_after_init Ard Biesheuvel
2017-08-14 12:53   ` [kernel-hardening] " Ard Biesheuvel
2017-08-14 14:26   ` Arnd Bergmann
2017-08-14 14:26     ` [kernel-hardening] " Arnd Bergmann
2017-08-14 12:53 ` [PATCH 02/30] ARM: assembler: introduce adr_l, ldr_l and str_l macros Ard Biesheuvel
2017-08-14 12:53   ` [kernel-hardening] " Ard Biesheuvel
2017-08-14 15:29   ` Dave Martin
2017-08-14 15:29     ` [kernel-hardening] " Dave Martin
2017-08-14 15:38     ` Ard Biesheuvel
2017-08-14 15:38       ` [kernel-hardening] " Ard Biesheuvel
2017-08-14 15:50       ` Dave Martin
2017-08-14 15:50         ` [kernel-hardening] " Dave Martin
2017-08-14 16:18         ` Nicolas Pitre
2017-08-14 16:18           ` [kernel-hardening] " Nicolas Pitre
2017-08-14 16:22           ` Ard Biesheuvel
2017-08-14 16:22             ` [kernel-hardening] " Ard Biesheuvel
2017-08-14 16:33             ` Nicolas Pitre
2017-08-14 16:33               ` [kernel-hardening] " Nicolas Pitre
2017-08-14 16:42             ` Russell King - ARM Linux
2017-08-14 16:42               ` [kernel-hardening] " Russell King - ARM Linux
2017-08-14 16:56               ` Ard Biesheuvel
2017-08-14 16:56                 ` [kernel-hardening] " Ard Biesheuvel
2017-08-14 15:32   ` Dave Martin
2017-08-14 15:32     ` [kernel-hardening] " Dave Martin
2017-08-14 15:40     ` Ard Biesheuvel
2017-08-14 15:40       ` [kernel-hardening] " Ard Biesheuvel
2017-08-14 15:53       ` Dave Martin
2017-08-14 15:53         ` [kernel-hardening] " Dave Martin
2017-08-14 12:53 ` [PATCH 03/30] ARM: head-common.S: use PC-relative insn sequence for __proc_info Ard Biesheuvel
2017-08-14 12:53   ` [kernel-hardening] " Ard Biesheuvel
2017-08-14 12:53 ` [PATCH 04/30] ARM: head-common.S: use PC-relative insn sequence for idmap creation Ard Biesheuvel
2017-08-14 12:53   ` [kernel-hardening] " Ard Biesheuvel
2017-08-14 12:53 ` Ard Biesheuvel [this message]
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 ` [PATCH 06/30] ARM: kernel: use relative references for UP/SMP alternatives Ard Biesheuvel
2017-08-14 12:53   ` [kernel-hardening] " Ard Biesheuvel
2017-08-14 12:53 ` [PATCH 07/30] ARM: head: use PC-relative insn sequence for __smp_alt Ard Biesheuvel
2017-08-14 12:53   ` [kernel-hardening] " Ard Biesheuvel
2017-08-14 12:53 ` [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] " Ard Biesheuvel
2017-08-14 12:53 ` [PATCH 09/30] ARM: head.S: use PC-relative insn sequences for __fixup_pv_table Ard Biesheuvel
2017-08-14 12:53   ` [kernel-hardening] " Ard Biesheuvel
2017-08-14 12:53 ` [PATCH 10/30] ARM: head.S: use PC relative insn sequence to calculate PHYS_OFFSET Ard Biesheuvel
2017-08-14 12:53   ` [kernel-hardening] " Ard Biesheuvel
2017-08-14 12:53 ` [PATCH 11/30] ARM: kvm: replace open coded VA->PA calculations with adr_l call Ard Biesheuvel
2017-08-14 12:53   ` [kernel-hardening] " Ard Biesheuvel
2017-08-14 12:53 ` [PATCH 12/30] arm-soc: exynos: replace open coded VA->PA conversions Ard Biesheuvel
2017-08-14 12:53   ` [kernel-hardening] " Ard Biesheuvel
2017-08-14 12:53 ` [PATCH 13/30] arm-soc: mvebu: replace open coded VA->PA conversion Ard Biesheuvel
2017-08-14 12:53   ` [kernel-hardening] " Ard Biesheuvel
2017-08-14 12:53 ` [PATCH 14/30] arm-soc: various: replace open coded VA->PA calculation of pen_release Ard Biesheuvel
2017-08-14 12:53   ` [kernel-hardening] " Ard Biesheuvel
2017-08-14 12:53 ` [PATCH 15/30] ARM: kernel: switch to relative exception tables Ard Biesheuvel
2017-08-14 12:53   ` [kernel-hardening] " Ard Biesheuvel
2017-08-14 12:53 ` [PATCH 16/30] ARM: kernel: use relative phys-to-virt patch tables Ard Biesheuvel
2017-08-14 12:53   ` [kernel-hardening] " Ard Biesheuvel
2017-08-14 12:53 ` [PATCH 17/30] arm-soc: tegra: make sleep asm code runtime relocatable Ard Biesheuvel
2017-08-14 12:53   ` [kernel-hardening] " Ard Biesheuvel
2017-08-14 14:42   ` Dave Martin
2017-08-14 14:42     ` [kernel-hardening] " Dave Martin
2017-08-14 14:49     ` Ard Biesheuvel
2017-08-14 14:49       ` [kernel-hardening] " Ard Biesheuvel
2017-08-14 15:29       ` Dave Martin
2017-08-14 15:29         ` [kernel-hardening] " Dave Martin
2017-08-14 12:53 ` [PATCH 18/30] ARM: kernel: make vmlinux buildable as a PIE executable Ard Biesheuvel
2017-08-14 12:53   ` [kernel-hardening] " Ard Biesheuvel
2017-08-14 12:54 ` [PATCH 19/30] ARM: kernel: use PC-relative symbol references in MMU switch code Ard Biesheuvel
2017-08-14 12:54   ` [kernel-hardening] " Ard Biesheuvel
2017-08-14 12:54 ` [PATCH 20/30] ARM: kernel: use PC relative symbol references in suspend/resume code Ard Biesheuvel
2017-08-14 12:54   ` [kernel-hardening] " Ard Biesheuvel
2017-08-14 16:02   ` Nicolas Pitre
2017-08-14 16:02     ` [kernel-hardening] " Nicolas Pitre
2017-08-14 18:14     ` Ard Biesheuvel
2017-08-14 18:14       ` [kernel-hardening] " Ard Biesheuvel
2017-08-14 18:37       ` Nicolas Pitre
2017-08-14 18:37         ` [kernel-hardening] " Nicolas Pitre
2017-08-14 12:54 ` [PATCH 21/30] ARM: mm: export default vmalloc base address Ard Biesheuvel
2017-08-14 12:54   ` [kernel-hardening] " Ard Biesheuvel
2017-08-14 12:54 ` [PATCH 22/30] ARM: kernel: refer to swapper_pg_dir via its symbol Ard Biesheuvel
2017-08-14 12:54   ` [kernel-hardening] " Ard Biesheuvel
2017-08-14 12:54 ` [PATCH 23/30] ARM: kernel: implement randomization of the kernel load address Ard Biesheuvel
2017-08-14 12:54   ` [kernel-hardening] " Ard Biesheuvel
2017-08-14 12:54 ` [PATCH 24/30] ARM: decompressor: explicitly map decompressor binary cacheable Ard Biesheuvel
2017-08-14 12:54   ` [kernel-hardening] " Ard Biesheuvel
2017-08-14 12:54 ` [PATCH 25/30] ARM: compressed: factor out zImage header and make it extensible Ard Biesheuvel
2017-08-14 12:54   ` [kernel-hardening] " Ard Biesheuvel
2017-08-14 12:54 ` [PATCH 26/30] ARM: decompressor: add KASLR support Ard Biesheuvel
2017-08-14 12:54   ` [kernel-hardening] " Ard Biesheuvel
2017-08-14 12:54 ` [PATCH 27/30] efi/libstub: add 'max' parameter to efi_random_alloc() Ard Biesheuvel
2017-08-14 12:54   ` [kernel-hardening] " Ard Biesheuvel
2017-08-14 12:54 ` [PATCH 28/30] efi/libstub: check for vmalloc= command line argument Ard Biesheuvel
2017-08-14 12:54   ` [kernel-hardening] " Ard Biesheuvel
2017-08-14 12:54 ` [PATCH 29/30] efi/libstub: arm: reserve bootloader supplied initrd in memory map Ard Biesheuvel
2017-08-14 12:54   ` [kernel-hardening] " Ard Biesheuvel
2017-08-18 11:48   ` Ard Biesheuvel
2017-08-18 11:48     ` [kernel-hardening] " Ard Biesheuvel
2017-08-21 10:37   ` Mark Rutland
2017-08-21 10:37     ` [kernel-hardening] " Mark Rutland
2017-08-21 10:39     ` Ard Biesheuvel
2017-08-21 10:39       ` [kernel-hardening] " Ard Biesheuvel
2017-08-14 12:54 ` [PATCH 30/30] efi/libstub: arm: implement KASLR Ard Biesheuvel
2017-08-14 12:54   ` [kernel-hardening] " Ard Biesheuvel
2017-08-14 15:30 ` [PATCH 00/30] implement KASLR for ARM Arnd Bergmann
2017-08-14 15:30   ` [kernel-hardening] " Arnd Bergmann
2017-08-14 15:49   ` Ard Biesheuvel
2017-08-14 15:49     ` [kernel-hardening] " Ard Biesheuvel
2017-08-14 16:03     ` Arnd Bergmann
2017-08-14 16:03       ` [kernel-hardening] " Arnd Bergmann
2017-08-14 16:28       ` Nicolas Pitre
2017-08-14 16:28         ` [kernel-hardening] " Nicolas Pitre
2017-08-14 17:28         ` Ard Biesheuvel
2017-08-14 17:28           ` [kernel-hardening] " Ard Biesheuvel
2017-08-14 18:01           ` Nicolas Pitre
2017-08-14 18:01             ` [kernel-hardening] " Nicolas Pitre
2017-08-14 18:08             ` Ard Biesheuvel
2017-08-14 18:08               ` [kernel-hardening] " Ard Biesheuvel
2017-08-14 16:16     ` Nicolas Pitre
2017-08-14 16:16       ` [kernel-hardening] " Nicolas Pitre

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