On Fri, Sep 18, 2020 at 05:16:15PM +0200, Christoph Hellwig wrote: > On Fri, Sep 18, 2020 at 02:58:22PM +0100, Al Viro wrote: > > Said that, why not provide a variant that would take an explicit > > "is it compat" argument and use it there? And have the normal > > one pass in_compat_syscall() to that... > > That would help to not introduce a regression with this series yes. > But it wouldn't fix existing bugs when io_uring is used to access > read or write methods that use in_compat_syscall(). One example that > I recently ran into is drivers/scsi/sg.c. So screw such read/write methods - don't use them with io_uring. That, BTW, is one of the reasons I'm sceptical about burying the decisions deep into the callchain - we don't _want_ different data layouts on read/write depending upon the 32bit vs. 64bit caller, let alone the pointer-chasing garbage that is /dev/sg.
