Hi Ard, On 10/07/18 00:42, AKASHI Takahiro wrote: > From: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> > > The BGRT code validates the contents of the table against the UEFI > memory map, and so it expects it to be mapped when the code runs. > > On ARM, this is currently not the case, since we tear down the early > mapping after efi_init() completes, and only create the permanent > mapping in arm_enable_runtime_services(), which executes as an early > initcall, but still leaves a window where the UEFI memory map is not > mapped. > > So move the call to efi_memmap_unmap() from efi_init() to > arm_enable_runtime_services(). I don't have a machine that generates a BGRT, but I can see that efi_mem_type() call in efi_bgrt_init() would cause the same problems we have with kexec and acpi. > diff --git a/drivers/firmware/efi/arm-init.c b/drivers/firmware/efi/arm-init.c > index b5214c143fee..388a929baf95 100644 > --- a/drivers/firmware/efi/arm-init.c > +++ b/drivers/firmware/efi/arm-init.c > @@ -259,7 +259,6 @@ void __init efi_init(void) > > reserve_regions(); > efi_esrt_init(); > - efi_memmap_unmap(); > > memblock_reserve(params.mmap & PAGE_MASK, > PAGE_ALIGN(params.mmap_size + > diff --git a/drivers/firmware/efi/arm-runtime.c b/drivers/firmware/efi/arm-runtime.c > index 5889cbea60b8..59a8c0ec94d5 100644 > --- a/drivers/firmware/efi/arm-runtime.c > +++ b/drivers/firmware/efi/arm-runtime.c > @@ -115,6 +115,8 @@ static int __init arm_enable_runtime_services(void) > return 0; > } > > + efi_memmap_unmap(); This can get called twice if uefi_init() fails after setting the EFI_BOOT flag, but this can only happen if the system table signature is wrong, (or we're out of memory really early). I think this is harmless as we end up passing NULL to early_memunmap() which WARN()s and returns as its outside the fixmap range. Its just more noise on systems with a corrupt efi system table. Acked-by: James Morse <james.morse@xxxxxxx> Thanks, James _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec
