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From: Mark Brown <broonie@kernel.org>
To: Vincenzo Frascino <Vincenzo.Frascino@arm.com>,
	Will Deacon <will@kernel.org>,
	Catalin Marinas <catalin.marinas@arm.com>
Cc: Mark Brown <broonie@kernel.org>,
	Kees Cook <keescook@chromium.org>,
	linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2 01/10] arm64: bti: Support building kernel C code using BTI
Date: Wed, 29 Apr 2020 22:16:32 +0100	[thread overview]
Message-ID: <20200429211641.9279-2-broonie@kernel.org> (raw)
In-Reply-To: <20200429211641.9279-1-broonie@kernel.org>

When running with BTI enabled we need to ask the compiler to enable
generation of BTI landing pads beyond those generated as a result of
pointer authentication instructions being landing pads. Since the two
features are practically speaking unlikely to be used separately we
will make kernel mode BTI depend on pointer authentication in order
to simplify the Makefile.

Signed-off-by: Mark Brown <broonie@kernel.org>
---
 arch/arm64/Makefile | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
index 85e4149cc5d5..90150b5b180e 100644
--- a/arch/arm64/Makefile
+++ b/arch/arm64/Makefile
@@ -71,7 +71,11 @@ branch-prot-flags-y += $(call cc-option,-mbranch-protection=none)
 
 ifeq ($(CONFIG_ARM64_PTR_AUTH),y)
 branch-prot-flags-$(CONFIG_CC_HAS_SIGN_RETURN_ADDRESS) := -msign-return-address=all
+ifeq ($(CONFIG_ARM64_BTI_KERNEL),y)
+branch-prot-flags-$(CONFIG_CC_HAS_BRANCH_PROT_PAC_RET_BTI) := -mbranch-protection=pac-ret+leaf+bti
+else
 branch-prot-flags-$(CONFIG_CC_HAS_BRANCH_PROT_PAC_RET) := -mbranch-protection=pac-ret+leaf
+endif
 # -march=armv8.3-a enables the non-nops instructions for PAC, to avoid the
 # compiler to generate them and consequently to break the single image contract
 # we pass it only to the assembler. This option is utilized only in case of non
-- 
2.20.1


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  reply	other threads:[~2020-04-29 21:20 UTC|newest]

Thread overview: 38+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-04-29 21:16 [PATCH v2 00/10] arm64: BTI kernel and vDSO support Mark Brown
2020-04-29 21:16 ` Mark Brown [this message]
2020-05-05 16:50   ` [PATCH v2 01/10] arm64: bti: Support building kernel C code using BTI Dave Martin
2020-05-05 17:31     ` Mark Brown
2020-05-06 12:24       ` Amit Kachhap
2020-04-29 21:16 ` [PATCH v2 02/10] arm64: asm: Override SYM_FUNC_START when building the kernel with BTI Mark Brown
2020-05-05 14:56   ` Will Deacon
2020-05-05 15:18     ` Mark Brown
2020-05-05 16:08       ` Will Deacon
2020-05-05 17:21         ` Mark Brown
2020-05-06  7:10           ` Will Deacon
2020-05-06 10:41             ` Mark Brown
2020-05-06 10:50               ` Will Deacon
2020-05-06 11:43                 ` Mark Brown
2020-05-06 12:27                   ` Will Deacon
2020-05-06 13:03                     ` Mark Brown
2020-05-06 13:40                 ` Dave Martin
2020-05-06 14:45                   ` Will Deacon
2020-05-06 15:25                     ` Mark Brown
2020-05-06 15:48                       ` Will Deacon
2020-05-06 15:33                     ` Dave Martin
2020-04-29 21:16 ` [PATCH v2 03/10] arm64: Set GP bit in kernel page tables to enable BTI for the kernel Mark Brown
2020-04-29 21:16 ` [PATCH v2 04/10] arm64: bpf: Annotate JITed code for BTI Mark Brown
2020-04-29 21:16 ` [PATCH v2 05/10] arm64: mm: Mark executable text as guarded pages Mark Brown
2020-04-29 21:16 ` [PATCH v2 06/10] arm64: bti: Provide Kconfig for kernel mode BTI Mark Brown
2020-04-29 21:16 ` [PATCH v2 07/10] arm64: asm: Provide a mechanism for generating ELF note for BTI Mark Brown
2020-05-05 14:58   ` Will Deacon
2020-05-05 16:51     ` Dave Martin
2020-05-05 17:06     ` Mark Brown
2020-05-06 11:26       ` Will Deacon
2020-05-06 12:38         ` Mark Brown
2020-05-06 13:44           ` Will Deacon
2020-05-06 15:39             ` Mark Brown
2020-04-29 21:16 ` [PATCH v2 08/10] arm64: vdso: Annotate " Mark Brown
2020-04-29 21:16 ` [PATCH v2 09/10] arm64: vdso: Force the vDSO to be linked as BTI when built " Mark Brown
2020-04-29 21:16 ` [PATCH v2 10/10] arm64: vdso: Map the vDSO text with guarded pages " Mark Brown
2020-04-30 17:18 ` [PATCH v2 00/10] arm64: BTI kernel and vDSO support Catalin Marinas
2020-04-30 17:23   ` Mark Brown

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