3.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Matt Fleming <matt.flem...@intel.com>
commit fb834c7acc5e140cf4f9e86da93a66de8c0514da upstream.
commit 1de63d60cd5b ("efi: Clear EFI_RUNTIME_SERVICES rather than
EFI_BOOT by "noefi" boot parameter") attempted to make "noefi" true to
its documentation and disable EFI runtime services to prevent the
bricking bug described in commit e0094244e41c ("samsung-laptop:
Disable on EFI hardware"). However, it's not possible to clear
EFI_RUNTIME_SERVICES from an early param function because
EFI_RUNTIME_SERVICES is set in efi_init() *after* parse_early_param().
This resulted in "noefi" effectively becoming a no-op and no longer
providing users with a way to disable EFI, which is bad for those
users that have buggy machines.
Reported-by: Walt Nelson Jr <walt0...@gmail.com>
Cc: Satoru Takeuchi <takeuchi_sat...@jp.fujitsu.com>
Signed-off-by: Matt Fleming <matt.flem...@intel.com>
Link:
http://lkml.kernel.org/r/1361392572-25657-1-git-send-email-m...@console-pimps.org
Signed-off-by: H. Peter Anvin <h...@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
arch/x86/platform/efi/efi.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -84,9 +84,10 @@ int efi_enabled(int facility)
}
EXPORT_SYMBOL(efi_enabled);
+static bool disable_runtime = false;
static int __init setup_noefi(char *arg)
{
- clear_bit(EFI_RUNTIME_SERVICES, &x86_efi_facility);
+ disable_runtime = true;
return 0;
}
early_param("noefi", setup_noefi);
@@ -733,7 +734,7 @@ void __init efi_init(void)
if (!efi_is_native())
pr_info("No EFI runtime due to 32/64-bit mismatch with
kernel\n");
else {
- if (efi_runtime_init())
+ if (disable_runtime || efi_runtime_init())
return;
set_bit(EFI_RUNTIME_SERVICES, &x86_efi_facility);
}
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
