| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.11 049/150] efi/bgrt: Skip efi_bgrt_init() in case of non-EFI boot | Date | Mon, 12 Jun 2017 17:24:16 +0200 |
| |
4.11-stable review patch. If anyone has any objections, please let me know.
------------------
From: Dave Young <dyoung@redhat.com>
commit 7425826f4f7ac60f2538b06a7f0a5d1006405159 upstream.
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: 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- arch/x86/platform/efi/efi-bgrt.c | 3 +++ 1 file changed, 3 insertions(+)
--- a/arch/x86/platform/efi/efi-bgrt.c +++ b/arch/x86/platform/efi/efi-bgrt.c @@ -36,6 +36,9 @@ void __init efi_bgrt_init(struct acpi_ta if (acpi_disabled) return; + if (!efi_enabled(EFI_BOOT)) + return; + if (table->length < sizeof(bgrt_tab)) { pr_notice("Ignoring BGRT: invalid length %u (expected %zu)\n", table->length, sizeof(bgrt_tab));
|