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[v10,01/40] arm64/mm: Restructure arch_validate_flags() for extensibility

Message ID 20240801-arm64-gcs-v10-1-699e2bd2190b@kernel.org (mailing list archive)
State New
Headers show
Series arm64/gcs: Provide support for GCS in userspace | expand

Commit Message

Mark Brown Aug. 1, 2024, 12:06 p.m. UTC 
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.

Reviewed-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
---
 arch/arm64/include/asm/mman.h | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

Comments

Catalin Marinas Aug. 15, 2024, 10:39 a.m. UTC | #1 
On Thu, Aug 01, 2024 at 01:06:28PM +0100, Mark Brown wrote:
> 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.
> 
> Reviewed-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org>
> Signed-off-by: Mark Brown <broonie@kernel.org>

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
diff mbox series

Patch

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)