On Tue 2023-04-04 19:12:01, Jaewon Kim wrote: > >From: Jaewon Kim > >> Sent: 03 April 2023 15:40 > >... > >> I wanted to print phys_addr_t type value only when kptr_restrict sysctl is > >> allowed. So I thought I could use %pK for that purpose. And the physical > >> address is not that long. I wanted to make that length short like 9 hex. > > > >Isn't that is the wrong format for physical addresses anyway? > >They can be larger than virtual ones (eg x86 with PAE). > > Yeah, correct. I just used %pK to hide physical address, I thought it could be > leak in security perspective. Could you give me advice how I can hide the > address by default and look the address if kptr_restrict allow it? Could you please send a patch that would show what value you want to print? The initial mail mentioned converting %09lx to %09pK in some driver. Then it included a warning when compiling from mm/page_alloc.o Honestly, I think that you could just use %pK or %p. IMHO, it does not make sense to optimize it for the length. Anyway, there is still the question if the address is really worth printing. Will it really help to locate a potential problem? Best Regards, Petr
