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?
--
Kees Cook
