On Wed, Oct 06, 2010 at 10:48:59PM +0200, Andi Kleen wrote: > The original hwpoison code added a new siginfo field si_addr_lsb to > pass the granuality of the fault address to user space. Unfortunately > this field was never copied to user space. Fix this here. > > I added explicit checks for the MCEERR codes to avoid having > to patch all potential callers to initialize the field. That doesn't fly, see below. > --- a/kernel/signal.c > +++ b/kernel/signal.c > @@ -2215,6 +2215,14 @@ int copy_siginfo_to_user(siginfo_t __user *to, siginfo_t *from) > #ifdef __ARCH_SI_TRAPNO > err |= __put_user(from->si_trapno, &to->si_trapno); > #endif > +#ifdef BUS_MCEERR_AO > + /* > + * Other callers might not initialize the si_lsb field, > + * so check explicitely for the right codes here. > + */ > + if (from->si_code == BUS_MCEERR_AR || from->si_code == BUS_MCEERR_AO) > + err |= __put_user(from->si_addr_lsb, &to->si_addr_lsb); > +#endif include/asm-generic/siginfo.h defines BUS_MCEERR_AR unconditionally and is getting include in all <asm/siginfo.h> so that #ifdef condition is always true. struct siginfo.si_addr_lsb is defined only for the generic struct siginfo. The architectures that define HAVE_ARCH_SIGINFO_T (MIPS and IA-64) do not define this field so the build breaks. Ralf
