Thread (90 messages) 90 messages, 8 authors, 2024-03-14
STALE844d

[PATCH v8 01/38] arm64/mm: Restructure arch_validate_flags() for extensibility

From: Mark Brown <broonie@kernel.org>
Date: 2024-02-03 12:27:06
Also in: kvmarm, linux-arch, linux-arm-kernel, linux-fsdevel, linux-kselftest, linux-mm, linux-riscv, lkml
Subsystem: arm64 port (aarch64 architecture), the rest · Maintainers: Catalin Marinas, Will Deacon, Linus Torvalds

Currently arch_validate_flags() is written in a very non-extensible
fashion, returning immediately if MTE is not supported and writing the MTE
check as a direct return. Since we will want to add more checks for GCS
refactor the existing code to be more extensible, no functional change
intended.

Signed-off-by: Mark Brown <broonie@kernel.org>
---
 arch/arm64/include/asm/mman.h | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/arch/arm64/include/asm/mman.h b/arch/arm64/include/asm/mman.h
index 5966ee4a6154..c21849ffdd88 100644
--- a/arch/arm64/include/asm/mman.h
+++ b/arch/arm64/include/asm/mman.h
@@ -52,11 +52,17 @@ static inline bool arch_validate_prot(unsigned long prot,
 
 static inline bool arch_validate_flags(unsigned long vm_flags)
 {
-	if (!system_supports_mte())
-		return true;
+	if (system_supports_mte()) {
+		/*
+		 * only allow VM_MTE if VM_MTE_ALLOWED has been set
+		 * previously
+		 */
+		if ((vm_flags & VM_MTE) && !(vm_flags & VM_MTE_ALLOWED))
+			return false;
+	}
+
+	return true;
 
-	/* only allow VM_MTE if VM_MTE_ALLOWED has been set previously */
-	return !(vm_flags & VM_MTE) || (vm_flags & VM_MTE_ALLOWED);
 }
 #define arch_validate_flags(vm_flags) arch_validate_flags(vm_flags)
 
-- 
2.30.2
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