On 9/26/20 10:58 AM, Ard Biesheuvel wrote: > Currently, on arm64, we abort on any failure from efi_get_random_bytes() > other than EFI_NOT_FOUND when it comes to setting the physical seed for > KASLR, but ignore such failures when obtaining the seed for virtual > KASLR or for early seeding of the kernel's entropy pool via the config > table. This is inconsistent, and may lead to unexpected boot failures. > > So let's permit any failure for the physical seed, and simply report > the error code if it does not equal EFI_NOT_FOUND. > > Reported-by: Heinrich Schuchardt <xypron.glpk@xxxxxx> > Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx> Hello Ard, thank you for providing the patch. Unfortunately this seems not to be enough for booting with an EFI_RNG_PROTOCOL.GetRng() returning EFI_UNSUPPORTED. This is the output I received on v5.9-rc6, defconfig with your patch applied. I can retry with a branch from https://git.kernel.org/pub/scm/linux/kernel/git/efi/efi.git/ if you indicate which one to use. EFI stub: Booting Linux Kernel... EFI stub: ERROR: efi_get_random_bytes() failed (0x8000000000000003), KASLR will be disabled EFI stub: Using DTB from configuration table EFI stub: Exiting boot services and installing virtual address map... EFI stub: ERROR: Unable to construct new device tree. EFI stub: ERROR: Failed to update FDT and exit boot services This matches the problem originally reported by Scott. Best regards Heinrich > --- > drivers/firmware/efi/libstub/arm64-stub.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/drivers/firmware/efi/libstub/arm64-stub.c b/drivers/firmware/efi/libstub/arm64-stub.c > index e5bfac79e5ac..21692a986beb 100644 > --- a/drivers/firmware/efi/libstub/arm64-stub.c > +++ b/drivers/firmware/efi/libstub/arm64-stub.c > @@ -62,10 +62,10 @@ efi_status_t handle_kernel_image(unsigned long *image_addr, > status = efi_get_random_bytes(sizeof(phys_seed), > (u8 *)&phys_seed); > if (status == EFI_NOT_FOUND) { > - efi_info("EFI_RNG_PROTOCOL unavailable, no randomness supplied\n"); > + efi_info("EFI_RNG_PROTOCOL unavailable, KASLR will be disabled\n"); > } else if (status != EFI_SUCCESS) { > - efi_err("efi_get_random_bytes() failed\n"); > - return status; > + efi_err("efi_get_random_bytes() failed (0x%lx), KASLR will be disabled\n", > + status); > } > } else { > efi_info("KASLR disabled on kernel command line\n"); >
