On 02/13, Gregory Price wrote: > > On Mon, Feb 13, 2023 at 09:26:21PM +0100, Thomas Gleixner wrote: > > On Fri, Feb 10 2023 at 02:25, Gregory Price wrote: > > > +struct ptrace_sud_config { > > > + __u64 mode; > > > + __s8 *selector; > > > > How is this correct for a 32bit ptracer running on a 64bit kernel? Aside > > of not wiring up the compat syscall without any argumentation in the > > changelog. > > > > I'm having a little trouble wrapping my head around what is "right" here > with regard to compat. Granted I've never had to deal with compat > issues, so please excuse the ignorance if this is a trivial issue. The problem is the sizeof(selector). 4 bytes for 32bit ptracer but the kernel will write 8 bytes. I think you should make "selector" __u64 too. Oleg.