Re: [PATCH mm v3 29/38] kasan, vmalloc: add vmalloc tagging for HW_TAGS
From: Marco Elver <elver@google.com>
Date: 2021-12-14 19:56:12
Also in:
linux-mm, lkml
On Mon, Dec 13, 2021 at 10:54PM +0100, andrey.konovalov@linux.dev wrote: [...]
+ /* + * Skip page_alloc poisoning and zeroing for pages backing VM_ALLOC + * mappings. Only effective in HW_TAGS mode. + */ + gfp &= __GFP_SKIP_KASAN_UNPOISON & __GFP_SKIP_ZERO;
This will turn gfp == 0 always. Should it have been gfp |= __GFP_SKIP_KASAN_UNPOISON | __GFP_SKIP_ZERO Also, not sure it matters, but on non-KASAN builds, this will now always generate an extra instruction. You could conditionally define GFP_SKIP* only in the KASAN modes that need them, otherwise they become 0, so the compiler optimizes this out. (Although I think it does does complicate GFP_SHIFT a little?) _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel