On Tue, 24 Sep 2019 at 01:17, Kees Cook <keesc...@chromium.org> wrote: > > On Fri, Sep 06, 2019 at 10:34:47AM -0700, Ard Biesheuvel wrote: > > On Fri, 6 Sep 2019 at 03:44, Will Deacon <w...@kernel.org> wrote: > > > > > > On Wed, Sep 04, 2019 at 01:38:04PM -0700, Kees Cook wrote: > > > > On Wed, Sep 04, 2019 at 11:38:03AM +0100, Will Deacon wrote: > > > > > On Wed, Aug 14, 2019 at 01:55:50PM -0700, Kees Cook wrote: > > > > > > diff --git a/drivers/firmware/efi/libstub/arm64-stub.c > > > > > > b/drivers/firmware/efi/libstub/arm64-stub.c > > > > > > index 1550d244e996..24022f956e01 100644 > > > > > > --- a/drivers/firmware/efi/libstub/arm64-stub.c > > > > > > +++ b/drivers/firmware/efi/libstub/arm64-stub.c > > > > > > @@ -111,6 +111,8 @@ efi_status_t > > > > > > handle_kernel_image(efi_system_table_t *sys_table_arg, > > > > > > status = efi_random_alloc(sys_table_arg, *reserve_size, > > > > > > MIN_KIMG_ALIGN, reserve_addr, > > > > > > (u32)phys_seed); > > > > > > + if (status != EFI_SUCCESS) > > > > > > + pr_efi_err(sys_table_arg, "KASLR allocate_pages() > > > > > > failed\n"); > > > > > > > > > > > > *image_addr = *reserve_addr + offset; > > > > > > } else { > > > > > > @@ -135,6 +137,8 @@ efi_status_t > > > > > > handle_kernel_image(efi_system_table_t *sys_table_arg, > > > > > > EFI_LOADER_DATA, > > > > > > *reserve_size / EFI_PAGE_SIZE, > > > > > > (efi_physical_addr_t > > > > > > *)reserve_addr); > > > > > > + if (status != EFI_SUCCESS) > > > > > > + pr_efi_err(sys_table_arg, "regular > > > > > > allocate_pages() failed\n"); > > > > > > } > > > > > > > > > > Not sure I see the need to distinsuish the 'KASLR' case from the > > > > > 'regular' > > > > > case -- only one should run, right? That also didn't seem to be part > > > > > of > > > > > the use-case in the commit, unless I'm missing something. > > > > > > > > I just did that to help with differentiating the cases. Maybe something > > > > was special about KASLR picking the wrong location that triggered the > > > > failure, etc. > > > > > > > > > Maybe combine the prints as per the diff below? > > > > > > > > That could work. If you're against the KASLR vs regular thing, I can > > > > respin the patch? > > > > > > Happy to Ack it with that change, although I suppose it's ultimately up > > > to Ard :) > > > > > > > No objections from me, but I prefer Will's version. > > I took a look at this again... to report the failures as Will suggests, > it would look like this: > > --- a/drivers/firmware/efi/libstub/arm64-stub.c > +++ b/drivers/firmware/efi/libstub/arm64-stub.c > @@ -138,12 +138,14 @@ efi_status_t handle_kernel_image(efi_system_table_t > *sys_table_arg, > } > > if (status != EFI_SUCCESS) { > + pr_efi_err(sys_table_arg, "allocate_pages() failed\n"); > + > *reserve_size = kernel_memsize + TEXT_OFFSET; > status = efi_low_alloc(sys_table_arg, *reserve_size, > MIN_KIMG_ALIGN, reserve_addr); > > if (status != EFI_SUCCESS) { > - pr_efi_err(sys_table_arg, "Failed to relocate > kernel\n"); > + pr_efi_err(sys_table_arg, "efi_low_alloc() failed\n"); > *reserve_size = 0; > return status; > } > > My reasoning for putting the failure earlier is to differentiate which > path was taken where the allocate_pages() failed: either regular or > KASLR. If that's really not considered important here, I can send the > above patch... Thoughts? >
The first pr_efi_err() in the patch above complains about a condition that is not actually an error. If you are interested in recording the path taken through this function, I have no objections to putting a normal pr_efi() print inside the KASLR block that shows that the physical placement of the kernel is being randomized. Then, we can keep only the second pr_efi_err() above to report the failure.