Gabriel Paubert writes: > On Fri, Nov 21, 2008 at 10:52:14AM +1100, Paul Mackerras wrote: > > Joakim Tjernlund writes: > > > > > This little hack changes the kernel sys call handling in an crude > > > way and then it works. Apperently the kernel thinks is an error if the > > > syscall returns a value between -_LAST_ERRNO and -1. > > > > Try this patch and let me if it fixes it. If it does I'll push it > > upstream. > > With your patch, you won't get EFAULT if you pass a bad > address, but a constant, time independent value, unless > I miss something.
I think you are missing something, namely that I put the call to force_successful_syscall_return() AFTER the return -EFAULT. You should get an EFAULT error if the address is bad, i.e. on return to userspace with cr0.SO = 1 and r3 = EFAULT (note, not -EFAULT). On a non-error return you should get cr0.SO = 0 and r3 containing the return value (even if it's -EFAULT). It's possible that glibc will stuff it up again after that but I hope not. Paul. _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
