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| author |   Dave Young <dyoung@redhat.com> | 2017-05-26 12:36:51 +0100 |
|---|---|---|
| committer |   Ingo Molnar <mingo@kernel.org> | 2017-05-28 11:06:17 +0200 |
| commit | 7425826f4f7ac60f2538b06a7f0a5d1006405159 (patch) | |
| tree | 40bf8105a7a5313a6cf146592a85b948b21b3658 | |
| parent | x86/efi: Correct EFI identity mapping under 'efi=old_map' when KASLR is enabled (diff) | |
| download | linux-dev-7425826f4f7ac60f2538b06a7f0a5d1006405159.tar.xz linux-dev-7425826f4f7ac60f2538b06a7f0a5d1006405159.zip | |
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>
| -rw-r--r-- | drivers/firmware/efi/efi-bgrt.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/firmware/efi/efi-bgrt.c b/drivers/firmware/efi/efi-bgrt.c index 04ca8764f0c0..8bf27323f7a3 100644 --- a/drivers/firmware/efi/efi-bgrt.c +++ b/drivers/firmware/efi/efi-bgrt.c @@ -36,6 +36,9 @@ void __init efi_bgrt_init(struct acpi_table_header *table) 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)); |