On 04/11/19 at 08:16am, Junichi Nomura wrote: > On 4/11/19 5:09 PM, Borislav Petkov wrote: > > On Wed, Apr 10, 2019 at 11:34:51PM +0000, Junichi Nomura wrote: > >> But efi_get_rsdp_addr() needs to check whether the kernel was > >> kexec booted to avoid accessing invalid EFI table address. > >> efi_get_kexec_setup_data_addr() is the only method I know > >> to check if it was kexec-booted. > > > > Your v3 had the right approach - you first check if you can get the > > address as a kexec-ed kernel. If you do, you use that one and continue > > the normal path. > > > > If you don't, you fall back to efi_get_rsdp_addr() and get it directly > > from EFI. > > > > And then carve out the functionality you need to call multiple times in > > helper functions like __efi_get_rsdp_addr(). > > > > Why doesn't that work anymore? > > kexec_get_rsdp_addr() might fail on kexec-booted kernel, e.g. if the > setup_data was invalid. In such a case, falling back to efi_get_rsdp_addr() > will hit the problem of accessing invalid table pointer again. Seems you are trying to address Dave Young's comment in http://lkml.kernel.org/r/20190404073233.GC5708@xxxxxxxxxxxxxxxxxxxxxxxxxx We may need discuss and make clear if those are doable. E.g the first comment, if not hang by below line of code, returning 0 for what? Can kexec still be saved, or just reset to firmware? error("EFI system table not found in kexec boot_params.") It may need be clarified firstly, then go further to rearrange patch. That can ease the work, I guess. Personal opinion. Thanks Baoquan _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec
