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| author | Ard Biesheuvel <ardb@kernel.org> | 2020-09-15 17:12:09 +0200 |
|---|---|---|
| committer | Ard Biesheuvel <ardb@kernel.org> | 2020-09-15 17:22:47 +0200 |
| commit | 46908326c6b801201f1e46f5ed0db6e85bef74ae (patch) | |
| tree | 188c86a4a9813c587dcc28c75f829def4fe2004c /drivers/firmware/efi/efibc.c | |
| parent | Documentation: efi: remove description of efi=old_map (diff) | |
| download | linux-46908326c6b801201f1e46f5ed0db6e85bef74ae.tar.xz linux-46908326c6b801201f1e46f5ed0db6e85bef74ae.zip | |
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>
Diffstat (limited to 'drivers/firmware/efi/efibc.c')
| -rw-r--r-- | drivers/firmware/efi/efibc.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/firmware/efi/efibc.c b/drivers/firmware/efi/efibc.c index 35dccc88ac0a..15a47539dc56 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); |