From: ard.biesheuvel@linaro.org (Ard Biesheuvel)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 19/30] ARM: kernel: use PC-relative symbol references in MMU switch code
Date: Mon, 14 Aug 2017 13:54:00 +0100 [thread overview]
Message-ID: <20170814125411.22604-20-ard.biesheuvel@linaro.org> (raw)
In-Reply-To: <20170814125411.22604-1-ard.biesheuvel@linaro.org>
To prepare for adding support for KASLR, which relocates all absolute
symbol references at runtime after the caches have been enabled,
update the MMU switch code to avoid using absolute symbol references
where possible. 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 | 39 ++++++++------------
1 file changed, 15 insertions(+), 24 deletions(-)
diff --git a/arch/arm/kernel/head-common.S b/arch/arm/kernel/head-common.S
index 06035488130c..b74477507a12 100644
--- a/arch/arm/kernel/head-common.S
+++ b/arch/arm/kernel/head-common.S
@@ -79,9 +79,10 @@ ENDPROC(__vet_atags)
*/
__INIT
__mmap_switched:
- adr r3, __mmap_switched_data
-
- ldmia r3!, {r4, r5, r6, r7}
+ adr_l r4, __data_loc
+ adr_l r5, _sdata
+ adr_l r6, __bss_start
+ adr_l r7, _end
cmp r4, r5 @ Copy data segment if needed
1: cmpne r5, r6
ldrne fp, [r4], #4
@@ -93,9 +94,17 @@ __mmap_switched:
strcc fp, [r6],#4
bcc 1b
- ARM( ldmia r3, {r4, r5, r6, r7, sp})
- THUMB( ldmia r3, {r4, r5, r6, r7} )
- THUMB( ldr sp, [r3, #16] )
+ adr_l r3, init_thread_union + THREAD_START_SP
+ mov sp, r3
+ adr_l r4, processor_id
+ adr_l r5, __machine_arch_type
+ adr_l r6, __atags_pointer
+#ifdef CONFIG_CPU_CP15
+ adr_l r7, cr_alignment
+#else
+ mov r7, #0
+#endif
+
str r9, [r4] @ Save processor ID
str r1, [r5] @ Save machine type
str r2, [r6] @ Save atags pointer
@@ -104,24 +113,6 @@ __mmap_switched:
b start_kernel
ENDPROC(__mmap_switched)
- .align 2
- .type __mmap_switched_data, %object
-__mmap_switched_data:
- .long __data_loc @ r4
- .long _sdata @ r5
- .long __bss_start @ r6
- .long _end @ r7
- .long processor_id @ r4
- .long __machine_arch_type @ r5
- .long __atags_pointer @ r6
-#ifdef CONFIG_CPU_CP15
- .long cr_alignment @ r7
-#else
- .long 0 @ r7
-#endif
- .long init_thread_union + THREAD_START_SP @ sp
- .size __mmap_switched_data, . - __mmap_switched_data
-
/*
* This provides a C-API version of __lookup_processor_type
*/
--
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 19/30] ARM: kernel: use PC-relative symbol references in MMU switch code
Date: Mon, 14 Aug 2017 13:54:00 +0100 [thread overview]
Message-ID: <20170814125411.22604-20-ard.biesheuvel@linaro.org> (raw)
In-Reply-To: <20170814125411.22604-1-ard.biesheuvel@linaro.org>
To prepare for adding support for KASLR, which relocates all absolute
symbol references at runtime after the caches have been enabled,
update the MMU switch code to avoid using absolute symbol references
where possible. 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 | 39 ++++++++------------
1 file changed, 15 insertions(+), 24 deletions(-)
diff --git a/arch/arm/kernel/head-common.S b/arch/arm/kernel/head-common.S
index 06035488130c..b74477507a12 100644
--- a/arch/arm/kernel/head-common.S
+++ b/arch/arm/kernel/head-common.S
@@ -79,9 +79,10 @@ ENDPROC(__vet_atags)
*/
__INIT
__mmap_switched:
- adr r3, __mmap_switched_data
-
- ldmia r3!, {r4, r5, r6, r7}
+ adr_l r4, __data_loc
+ adr_l r5, _sdata
+ adr_l r6, __bss_start
+ adr_l r7, _end
cmp r4, r5 @ Copy data segment if needed
1: cmpne r5, r6
ldrne fp, [r4], #4
@@ -93,9 +94,17 @@ __mmap_switched:
strcc fp, [r6],#4
bcc 1b
- ARM( ldmia r3, {r4, r5, r6, r7, sp})
- THUMB( ldmia r3, {r4, r5, r6, r7} )
- THUMB( ldr sp, [r3, #16] )
+ adr_l r3, init_thread_union + THREAD_START_SP
+ mov sp, r3
+ adr_l r4, processor_id
+ adr_l r5, __machine_arch_type
+ adr_l r6, __atags_pointer
+#ifdef CONFIG_CPU_CP15
+ adr_l r7, cr_alignment
+#else
+ mov r7, #0
+#endif
+
str r9, [r4] @ Save processor ID
str r1, [r5] @ Save machine type
str r2, [r6] @ Save atags pointer
@@ -104,24 +113,6 @@ __mmap_switched:
b start_kernel
ENDPROC(__mmap_switched)
- .align 2
- .type __mmap_switched_data, %object
-__mmap_switched_data:
- .long __data_loc @ r4
- .long _sdata @ r5
- .long __bss_start @ r6
- .long _end @ r7
- .long processor_id @ r4
- .long __machine_arch_type @ r5
- .long __atags_pointer @ r6
-#ifdef CONFIG_CPU_CP15
- .long cr_alignment @ r7
-#else
- .long 0 @ r7
-#endif
- .long init_thread_union + THREAD_START_SP @ sp
- .size __mmap_switched_data, . - __mmap_switched_data
-
/*
* This provides a C-API version of __lookup_processor_type
*/
--
2.11.0
next prev parent reply other threads:[~2017-08-14 12:54 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 ` [PATCH 05/30] ARM: head.S: use PC-relative insn sequence for secondary_data Ard Biesheuvel
2017-08-14 12:53 ` [kernel-hardening] " 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 ` Ard Biesheuvel [this message]
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 ` [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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