Hi Catalin, On 3/16/20 10:34 AM, Catalin Marinas wrote: [...] >> >> I tried to fine grain the headers as much as I could in order to avoid >> unneeded/unwanted inclusions: >> * TASK_SIZE_32 is used to verify ABI consistency on vdso32 (please refer to >> arch/arm64/kernel/vdso32/vgettimeofday.c). > > I see. But the test is probably useless. With 4K pages, TASK_SIZE_32 is > 1UL << 32, so you can't have a u32 greater than this. So I'd argue that > the ABI compatibility here doesn't matter. > > With 16K or 64K pages, TASK_SIZE_32 is slightly smaller but arm32 never > supported it. > > What's the side-effect of dropping this check altogether? > The main side-effect is that arm32 and arm64 compat have a different behavior, that it is what we want to avoid. The vdsotest [1] I am using, verifies all the side conditions with respect to the ABI, which we are now compatible with. Removing those checks would break this condition. [1] https://github.com/nlynch-mentor/vdsotest -- Regards, Vincenzo
