Commits
Dave Young committed 7425826f4f7
efi/bgrt: Skip efi_bgrt_init() in case of non-EFI boot Sabrina Dubroca reported an early panic: BUG: unable to handle kernel paging request at ffffffffff240001 IP: efi_bgrt_init+0xdc/0x134 [...] ---[ end Kernel panic - not syncing: Attempted to kill the idle task! ... which was introduced by: 7b0a911478c7 ("efi/x86: Move the EFI BGRT init code to early init code") The cause is that on this machine the firmware provides the EFI ACPI BGRT table even on legacy non-EFI bootups - which table should be EFI only. The garbage BGRT data causes the efi_bgrt_init() panic. Add a check to skip efi_bgrt_init() in case non-EFI bootup to work around this firmware bug. Tested-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: Dave Young <dyoung@redhat.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Cc: <stable@vger.kernel.org> # v4.11+ Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Fixes: 7b0a911478c7 ("efi/x86: Move the EFI BGRT init code to early init code") Link: http://lkml.kernel.org/r/20170526113652.21339-6-matt@codeblueprint.co.uk [ Rewrote the changelog to be more readable. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>