On Fri, 17 May 2019 at 11:06, Gen Zhang <blackgod016574@xxxxxxxxx> wrote: > > On Fri, May 17, 2019 at 10:41:28AM +0200, Ard Biesheuvel wrote: > > Returning an error here is not going to make much difference, given > > that the caller of efi_call_phys_prolog() does not bother to check it, > > and passes the result straight into efi_call_phys_epilog(), which > > happily attempts to dereference it. > > > > So if you want to fix this properly, please fix it at the call site as > > well. I'd prefer to avoid ERR_PTR() and just return NULL for a failed > > allocation though. > Hi Ard, > Thanks for your timely reply! > I think returning NULL in efi_call_phys_prolog() and checking in > efi_call_phys_epilog() is much better. But I am confused what to return > in efi_call_phys_epilog() if save_pgd is NULL. Definitely not return > -ENOMEM, because efi_call_phys_epilog() returns unsigned long. Could > please light on me to fix this problem? If efi_call_phys_prolog() returns NULL, the calling function should abort and never call efi_call_phys_epilog().
