Re: [PATCH v2 1/5] arm64: kasan: allow to init memory when setting tags
From: Catalin Marinas <catalin.marinas@arm.com>
Date: 2021-03-08 16:59:35
Also in:
linux-mm, lkml
On Mon, Mar 08, 2021 at 04:55:14PM +0100, Andrey Konovalov wrote:
quoted hunk ↗ jump to hunk
@@ -68,10 +69,16 @@ static inline void mte_set_mem_tag_range(void *addr, size_t size, u8 tag) * 'asm volatile' is required to prevent the compiler to move * the statement outside of the loop. */ - asm volatile(__MTE_PREAMBLE "stg %0, [%0]" - : - : "r" (curr) - : "memory"); + if (init) + asm volatile(__MTE_PREAMBLE "stzg %0, [%0]" + : + : "r" (curr) + : "memory"); + else + asm volatile(__MTE_PREAMBLE "stg %0, [%0]" + : + : "r" (curr) + : "memory"); curr += MTE_GRANULE_SIZE; } while (curr != end);
Is 'init' always a built-in constant here? If not, checking it once outside the loop may be better (or check the code generation, maybe the compiler is smart enough). -- Catalin _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel