If the sentinel triggers, we do not want the boot loader authors to
just poke it and make the error go away, we want them to actually fix
the problem.
This should help avoid making the incorrect change in non-compliant
bootloaders.
[ hpa: dropped the Documentation/x86/boot.txt hunk pending
clarifications ]
Signed-off-by: Peter Jones <pjones@redhat.com>
Link: http://lkml.kernel.org/r/1362592823-28967-1-git-send-email-pjones@redhat.com
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
When boot_params->sentinel is set, all we really know is that some
undefined set of fields in struct boot_params contain garbage. In the
particular case of efi_info, however, there is a private magic for
that substructure, so it is generally safe to leave it even if the
bootloader is broken.
kexec (for which we did the initial analysis) did not initialize this
field, but of course all the EFI bootloaders do, and most EFI
bootloaders are broken in this respect (and should be fixed.)
Reported-by: Robin Holt <holt@sgi.com>
Link: http://lkml.kernel.org/r/CA%2B5PVA51-FT14p4CRYKbicykugVb=PiaEycdQ57CK2km_OQuRQ@mail.gmail.com
Tested-by: Josh Boyer <jwboyer@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Use the new sentinel field to detect bootloaders which fail to follow
protocol and don't initialize fields in struct boot_params that they
do not explicitly initialize to zero.
Based on an original patch and research by Yinghai Lu.
Changed by hpa to be invoked both in the decompression path and in the
kernel proper; the latter for the case where a bootloader takes over
decompression.
Originally-by: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1359058816-7615-26-git-send-email-yinghai@kernel.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
