From: ard.biesheuvel@linaro.org (Ard Biesheuvel)
To: linux-arm-kernel@lists.infradead.org
Subject: [RFC PATCH 06/10] arm64: kbuild: reserve reg x18 from general allocation by the compiler
Date: Wed, 12 Jul 2017 15:44:19 +0100 [thread overview]
Message-ID: <20170712144424.19528-7-ard.biesheuvel@linaro.org> (raw)
In-Reply-To: <20170712144424.19528-1-ard.biesheuvel@linaro.org>
Before we can start using register x18 for a special purpose (as permitted
by the AAPCS64 ABI), we need to tell the compiler that it is off limits
for general allocation. So tag it as 'fixed', and remove the mention from
the LL/SC compiler flag override.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
arch/arm64/Makefile | 2 +-
arch/arm64/lib/Makefile | 3 +--
2 files changed, 2 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
index 9b41f1e3b1a0..68164338185a 100644
--- a/arch/arm64/Makefile
+++ b/arch/arm64/Makefile
@@ -46,7 +46,7 @@ $(warning Detected assembler with broken .inst; disassembly will be unreliable)
endif
KBUILD_CFLAGS += -mgeneral-regs-only $(lseinstr) $(brokengasinst)
-KBUILD_CFLAGS += -fno-asynchronous-unwind-tables
+KBUILD_CFLAGS += -fno-asynchronous-unwind-tables -ffixed-x18
KBUILD_CFLAGS += $(call cc-option, -mpc-relative-literal-loads)
KBUILD_AFLAGS += $(lseinstr) $(brokengasinst)
diff --git a/arch/arm64/lib/Makefile b/arch/arm64/lib/Makefile
index c86b7909ef31..b52f34fd5ba5 100644
--- a/arch/arm64/lib/Makefile
+++ b/arch/arm64/lib/Makefile
@@ -15,5 +15,4 @@ CFLAGS_atomic_ll_sc.o := -fcall-used-x0 -ffixed-x1 -ffixed-x2 \
-ffixed-x3 -ffixed-x4 -ffixed-x5 -ffixed-x6 \
-ffixed-x7 -fcall-saved-x8 -fcall-saved-x9 \
-fcall-saved-x10 -fcall-saved-x11 -fcall-saved-x12 \
- -fcall-saved-x13 -fcall-saved-x14 -fcall-saved-x15 \
- -fcall-saved-x18
+ -fcall-saved-x13 -fcall-saved-x14 -fcall-saved-x15
--
2.9.3
WARNING: multiple messages have this Message-ID (diff)
From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
To: linux-arm-kernel@lists.infradead.org,
kernel-hardening@lists.openwall.com
Cc: mark.rutland@arm.com, labbott@fedoraproject.org,
will.deacon@arm.com, dave.martin@arm.com,
catalin.marinas@arm.com,
Ard Biesheuvel <ard.biesheuvel@linaro.org>
Subject: [kernel-hardening] [RFC PATCH 06/10] arm64: kbuild: reserve reg x18 from general allocation by the compiler
Date: Wed, 12 Jul 2017 15:44:19 +0100 [thread overview]
Message-ID: <20170712144424.19528-7-ard.biesheuvel@linaro.org> (raw)
In-Reply-To: <20170712144424.19528-1-ard.biesheuvel@linaro.org>
Before we can start using register x18 for a special purpose (as permitted
by the AAPCS64 ABI), we need to tell the compiler that it is off limits
for general allocation. So tag it as 'fixed', and remove the mention from
the LL/SC compiler flag override.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
arch/arm64/Makefile | 2 +-
arch/arm64/lib/Makefile | 3 +--
2 files changed, 2 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
index 9b41f1e3b1a0..68164338185a 100644
--- a/arch/arm64/Makefile
+++ b/arch/arm64/Makefile
@@ -46,7 +46,7 @@ $(warning Detected assembler with broken .inst; disassembly will be unreliable)
endif
KBUILD_CFLAGS += -mgeneral-regs-only $(lseinstr) $(brokengasinst)
-KBUILD_CFLAGS += -fno-asynchronous-unwind-tables
+KBUILD_CFLAGS += -fno-asynchronous-unwind-tables -ffixed-x18
KBUILD_CFLAGS += $(call cc-option, -mpc-relative-literal-loads)
KBUILD_AFLAGS += $(lseinstr) $(brokengasinst)
diff --git a/arch/arm64/lib/Makefile b/arch/arm64/lib/Makefile
index c86b7909ef31..b52f34fd5ba5 100644
--- a/arch/arm64/lib/Makefile
+++ b/arch/arm64/lib/Makefile
@@ -15,5 +15,4 @@ CFLAGS_atomic_ll_sc.o := -fcall-used-x0 -ffixed-x1 -ffixed-x2 \
-ffixed-x3 -ffixed-x4 -ffixed-x5 -ffixed-x6 \
-ffixed-x7 -fcall-saved-x8 -fcall-saved-x9 \
-fcall-saved-x10 -fcall-saved-x11 -fcall-saved-x12 \
- -fcall-saved-x13 -fcall-saved-x14 -fcall-saved-x15 \
- -fcall-saved-x18
+ -fcall-saved-x13 -fcall-saved-x14 -fcall-saved-x15
--
2.9.3
next prev parent reply other threads:[~2017-07-12 14:44 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-07-12 14:44 [RFC PATCH 00/10] arm64: allow virtually mapped stacks to be enabled Ard Biesheuvel
2017-07-12 14:44 ` [kernel-hardening] " Ard Biesheuvel
2017-07-12 14:44 ` [RFC PATCH 01/10] arm64/lib: copy_page: use consistent prefetch stride Ard Biesheuvel
2017-07-12 14:44 ` [kernel-hardening] " Ard Biesheuvel
2017-07-12 14:44 ` [RFC PATCH 02/10] arm64/lib: copy_page: avoid x18 register in assembler code Ard Biesheuvel
2017-07-12 14:44 ` [kernel-hardening] " Ard Biesheuvel
2017-07-12 14:44 ` [RFC PATCH 03/10] arm64: crypto: avoid register x18 in scalar AES code Ard Biesheuvel
2017-07-12 14:44 ` [kernel-hardening] " Ard Biesheuvel
2017-07-12 14:44 ` [RFC PATCH 04/10] arm64: kvm: stop treating register x18 as caller save Ard Biesheuvel
2017-07-12 14:44 ` [kernel-hardening] " Ard Biesheuvel
2017-07-12 14:44 ` [RFC PATCH 05/10] arm64: kernel: avoid x18 as an arbitrary temp register Ard Biesheuvel
2017-07-12 14:44 ` [kernel-hardening] " Ard Biesheuvel
2017-07-12 14:44 ` Ard Biesheuvel [this message]
2017-07-12 14:44 ` [kernel-hardening] [RFC PATCH 06/10] arm64: kbuild: reserve reg x18 from general allocation by the compiler Ard Biesheuvel
2017-07-12 14:44 ` [RFC PATCH 07/10] arm64: kernel: switch to register x18 as a task struct pointer Ard Biesheuvel
2017-07-12 14:44 ` [kernel-hardening] " Ard Biesheuvel
2017-07-13 10:41 ` Dave Martin
2017-07-13 10:41 ` [kernel-hardening] " Dave Martin
2017-07-13 12:27 ` Ard Biesheuvel
2017-07-13 12:27 ` [kernel-hardening] " Ard Biesheuvel
2017-07-13 14:11 ` Dave Martin
2017-07-13 14:11 ` [kernel-hardening] " Dave Martin
2017-07-12 14:44 ` [RFC PATCH 08/10] arm64/kernel: dump entire stack if sp points elsewhere Ard Biesheuvel
2017-07-12 14:44 ` [kernel-hardening] " Ard Biesheuvel
2017-07-12 14:44 ` [RFC PATCH 09/10] arm64: mm: add C level handling for stack overflows Ard Biesheuvel
2017-07-12 14:44 ` [kernel-hardening] " Ard Biesheuvel
2017-07-12 14:44 ` [RFC PATCH 10/10] arm64: kernel: add support for virtually mapped stacks Ard Biesheuvel
2017-07-12 14:44 ` [kernel-hardening] " Ard Biesheuvel
2017-07-12 22:59 ` Mark Rutland
2017-07-12 22:59 ` [kernel-hardening] " Mark Rutland
2017-07-13 9:12 ` Mark Rutland
2017-07-13 9:12 ` Mark Rutland
2017-07-13 10:35 ` Dave Martin
2017-07-13 10:35 ` [kernel-hardening] " Dave Martin
2017-07-12 20:12 ` [RFC PATCH 00/10] arm64: allow virtually mapped stacks to be enabled Laura Abbott
2017-07-12 20:12 ` [kernel-hardening] " Laura Abbott
2017-07-12 20:49 ` Ard Biesheuvel
2017-07-12 20:49 ` [kernel-hardening] " Ard Biesheuvel
2017-07-12 21:32 ` Andy Lutomirski
2017-07-12 21:32 ` [kernel-hardening] " Andy Lutomirski
2017-07-12 22:47 ` Mark Rutland
2017-07-12 22:47 ` [kernel-hardening] " Mark Rutland
2017-07-13 6:51 ` Ard Biesheuvel
2017-07-13 6:51 ` [kernel-hardening] " Ard Biesheuvel
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