[PATCH v11 02/39] arm64/mm: Restructure arch_validate_flags() for extensibility

Mark Brown
2024-08-22T01:16:26Z

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>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
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)

--
2.39.2