Messages in this thread Patch in this message | | | Date | Wed, 20 Feb 2013 15:25:50 -0800 | From | tip-bot for Matt Fleming <> | Subject | [tip:x86/urgent] x86, efi: Make "noefi" really disable EFI runtime serivces |
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Commit-ID: fb834c7acc5e140cf4f9e86da93a66de8c0514da Gitweb: http://git.kernel.org/tip/fb834c7acc5e140cf4f9e86da93a66de8c0514da Author: Matt Fleming <matt.fleming@intel.com> AuthorDate: Wed, 20 Feb 2013 20:36:12 +0000 Committer: H. Peter Anvin <hpa@linux.intel.com> CommitDate: Wed, 20 Feb 2013 13:18:36 -0800
x86, efi: Make "noefi" really disable EFI runtime serivces
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 <walt0924@gmail.com> Cc: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com> Cc: <stable@vger.kernel.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com> Link: http://lkml.kernel.org/r/1361392572-25657-1-git-send-email-matt@console-pimps.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> --- arch/x86/platform/efi/efi.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c index 928bf83..e2cd38f 100644 --- a/arch/x86/platform/efi/efi.c +++ b/arch/x86/platform/efi/efi.c @@ -85,9 +85,10 @@ 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); @@ -734,7 +735,7 @@ 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); }
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