Hi Matt, First, thanks for your review! 於 四,2013-09-05 於 09:53 +0100,Matt Fleming 提到: > On Thu, 22 Aug, at 07:01:50PM, Lee, Chun-Yi wrote: > > +static int efi_status_to_err(efi_status_t status) > > +{ > > + int err; > > + > > + switch (status) { > > + case EFI_INVALID_PARAMETER: > > + err = -EINVAL; > > + break; > > + case EFI_OUT_OF_RESOURCES: > > + err = -ENOSPC; > > + break; > > + case EFI_DEVICE_ERROR: > > + err = -EIO; > > + break; > > + case EFI_WRITE_PROTECTED: > > + err = -EROFS; > > + break; > > + case EFI_SECURITY_VIOLATION: > > + err = -EACCES; > > + break; > > + case EFI_NOT_FOUND: > > + err = -ENODATA; > > + break; > > + default: > > + err = -EINVAL; > > + } > > + > > + return err; > > +} > > Please don't reimplement this. Instead make the existing function > global. > OK, I will make the function to global. > [...] > > > +static void *load_wake_key_data(unsigned long *datasize) > > +{ > > + u32 attr; > > + void *wkey_data; > > + efi_status_t status; > > + > > + if (!efi_enabled(EFI_RUNTIME_SERVICES)) > > + return ERR_PTR(-EPERM); > > + > > + /* obtain the size */ > > + *datasize = 0; > > + status = efi.get_variable(EFI_S4_WAKE_KEY_NAME, &EFI_HIBERNATE_GUID, > > + NULL, datasize, NULL); > > + if (status != EFI_BUFFER_TOO_SMALL) { > > + wkey_data = ERR_PTR(efi_status_to_err(status)); > > + pr_err("PM: Couldn't get wake key data size: 0x%lx\n", status); > > + goto error; > > + } > > Is it safe to completely bypass the efivars interface and access > efi.get_variable() directly? I wouldn't have thought so, unless you can > guarantee that the kernel isn't going to access any of the EFI runtime > services while you execute this function. > This S4WakeKey is a VOLATILE variable that could not modify by SetVariable() at runtime. So, it's read only even through efivars. Does it what your concern? Thanks a lot! Joey Lee -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html