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

Message ID 20240203-arm64-gcs-v8-1-c9fec77673ef@kernel.org
State New
Headers
Series arm64/gcs: Provide support for GCS in userspace |

Commit Message

Mark Brown Feb. 3, 2024, 12:25 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.

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

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)