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From: Mark Brown <broonie@kernel.org>
To: Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will@kernel.org>
Cc: Mark Brown <broonie@kernel.org>, linux-arm-kernel@lists.infradead.org
Subject: [PATCH] arm64: bti: Fix support for userspace only BTI
Date: Tue, 12 May 2020 10:21:55 +0100	[thread overview]
Message-ID: <20200512092155.56931-1-broonie@kernel.org> (raw)

When setting PTE_MAYBE_GP we check system_supports_bti() but this is
true for systems where only CONFIG_BTI is set causing us to enable BTI
on some kernel text. Add an extra check for the kernel mode option,
using an ifdef due to line length.

Fixes: c8027285e366 (arm64: Set GP bit in kernel page tables to enable BTI for the kernel)
Signed-off-by: Mark Brown <broonie@kernel.org>
---
 arch/arm64/include/asm/pgtable-prot.h | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/arm64/include/asm/pgtable-prot.h b/arch/arm64/include/asm/pgtable-prot.h
index 310690332896..3f07a044bdfb 100644
--- a/arch/arm64/include/asm/pgtable-prot.h
+++ b/arch/arm64/include/asm/pgtable-prot.h
@@ -32,7 +32,11 @@ extern bool arm64_use_ng_mappings;
 #define PTE_MAYBE_NG		(arm64_use_ng_mappings ? PTE_NG : 0)
 #define PMD_MAYBE_NG		(arm64_use_ng_mappings ? PMD_SECT_NG : 0)
 
+#ifdef CONFIG_ARM64_BTI_KERNEL
 #define PTE_MAYBE_GP		(system_supports_bti() ? PTE_GP : 0)
+#else
+#define PTE_MAYBE_GP		0
+#endif
 
 #define PROT_DEFAULT		(_PROT_DEFAULT | PTE_MAYBE_NG)
 #define PROT_SECT_DEFAULT	(_PROT_SECT_DEFAULT | PMD_MAYBE_NG)
-- 
2.20.1


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             reply	other threads:[~2020-05-12  9:22 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-12  9:21 Mark Brown [this message]
2020-05-12 10:39 ` [PATCH] arm64: bti: Fix support for userspace only BTI Will Deacon
2020-05-12 11:05   ` Mark Brown
2020-05-12 11:42     ` Will Deacon
2020-05-13 14:46     ` Dave Martin
2020-05-13 15:08       ` Mark Brown
2020-05-13 16:49         ` Dave Martin

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