Messages in this thread Patch in this message | | | Date | Fri, 18 Sep 2020 08:25:16 -0000 | From | "tip-bot2 for Ard Biesheuvel" <> | Subject | [tip: efi/urgent] efi: efibc: check for efivars write capability |
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The following commit has been merged into the efi/urgent branch of tip:
Commit-ID: 46908326c6b801201f1e46f5ed0db6e85bef74ae Gitweb: https://git.kernel.org/tip/46908326c6b801201f1e46f5ed0db6e85bef74ae Author: Ard Biesheuvel <ardb@kernel.org> AuthorDate: Tue, 15 Sep 2020 18:12:09 +03:00 Committer: Ard Biesheuvel <ardb@kernel.org> CommitterDate: Tue, 15 Sep 2020 18:22:47 +03:00
efi: efibc: check for efivars write capability
Branden reports that commit
f88814cc2578c1 ("efi/efivars: Expose RT service availability via efivars abstraction")
regresses UEFI platforms that implement GetVariable but not SetVariable when booting kernels that have EFIBC (bootloader control) enabled.
The reason is that EFIBC is a user of the efivars abstraction, which was updated to permit users that rely only on the read capability, but not on the write capability. EFIBC is in the latter category, so it has to check explicitly whether efivars supports writes.
Fixes: f88814cc2578c1 ("efi/efivars: Expose RT service availability via efivars abstraction") Tested-by: Branden Sherrell <sherrellbc@gmail.com> Link: https://lore.kernel.org/linux-efi/AE217103-C96F-4AFC-8417-83EC11962004@gmail.com/ Signed-off-by: Ard Biesheuvel <ardb@kernel.org> --- drivers/firmware/efi/efibc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/firmware/efi/efibc.c b/drivers/firmware/efi/efibc.c index 35dccc8..15a4753 100644 --- a/drivers/firmware/efi/efibc.c +++ b/drivers/firmware/efi/efibc.c @@ -84,7 +84,7 @@ static int __init efibc_init(void) { int ret; - if (!efi_enabled(EFI_RUNTIME_SERVICES)) + if (!efivars_kobject() || !efivar_supports_writes()) return -ENODEV; ret = register_reboot_notifier(&efibc_reboot_notifier);
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