On Wed, Nov 06, 2024 at 05:55:16PM +0800, Liao, Chang wrote: > 在 2024/9/19 20:17, Liao Chang 写道: > > On 09/23, Will Deacon wrote: > >> However, we should use __GFP_ZERO anyway > >> because I don't think it's a good idea to map an uninitialised page into > >> userspace. > > Agreed, and imo this even needs a separate "fix info leak" patch. > > > > Oleg. > > Given that Oleg's fix info leak patch has been merged [1], the risk of leakage > is gone. So I am looking forward to your options about this patch. As many > functions start with same instructions like 'stp fp, lr, [sp, #imm]' or > 'paciasp'. So I think this patch could avoid unnecessary D/I cache > synchronization. > > [1] https://lore.kernel.org/all/[email protected]/
The patch is fine with the fix in __create_xol_area(). But please add a comment on why it is safe to skip the cache maintenance, something like "the initial cache maintenance was done via set_pte_at()" (well, I can do this when applying). -- Catalin
