On Fri, Feb 21, 2025 at 4:27 PM Maciej Wieczor-Retman <maciej.wieczor-retman@xxxxxxxxx> wrote: > > Also I was wondering if you know what "hwasan-mapping-offset-dynamic" option is? > I noticed it in the llvm docs but can't find a good description what it does, > even from looking at the code in HWAddressSanitizer.cpp. If > hwasan-mapping-offset is not implemeneted for x86 I doubt this is but maybe it > could help in a cleaner makefile for x86 at least? Especially once these options > will be working in x86 llvm. Yeah, reading the code [1] works better to understand these options. My understanding is that specifying -hwasan-mapping-offset-dynamic=global without -hwasan-mapping-offset would make the generated code get the shadow memory address from the __hwasan_shadow_memory_dynamic_address global variable. This option is in the common code, so it should work on x86 too. But I believe it's intended for userspace, not sure if it would work for the kernel. Even if we use this option, I don't get how it would make the Makefile cleaner - to me it already looks clean tbh :) But it will possibly make KASAN work slower. [1] https://github.com/llvm/llvm-project/blob/llvmorg-21-init/llvm/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp#L1929
