53 lines
1.9 KiB
Diff
53 lines
1.9 KiB
Diff
From: Matt Fleming <matt.fleming@intel.com>
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Date: Wed, 20 Feb 2013 20:36:12 +0000
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Subject: x86, efi: Make "noefi" really disable EFI runtime serivces
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commit fb834c7acc5e140cf4f9e86da93a66de8c0514da upstream.
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commit 1de63d60cd5b ("efi: Clear EFI_RUNTIME_SERVICES rather than
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EFI_BOOT by "noefi" boot parameter") attempted to make "noefi" true to
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its documentation and disable EFI runtime services to prevent the
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bricking bug described in commit e0094244e41c ("samsung-laptop:
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Disable on EFI hardware"). However, it's not possible to clear
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EFI_RUNTIME_SERVICES from an early param function because
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EFI_RUNTIME_SERVICES is set in efi_init() *after* parse_early_param().
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This resulted in "noefi" effectively becoming a no-op and no longer
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providing users with a way to disable EFI, which is bad for those
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users that have buggy machines.
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Reported-by: Walt Nelson Jr <walt0924@gmail.com>
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Cc: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
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Signed-off-by: Matt Fleming <matt.fleming@intel.com>
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Link: http://lkml.kernel.org/r/1361392572-25657-1-git-send-email-matt@console-pimps.org
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Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
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---
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arch/x86/platform/efi/efi.c | 5 +++--
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1 file changed, 3 insertions(+), 2 deletions(-)
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diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
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index 928bf83..e2cd38f 100644
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--- a/arch/x86/platform/efi/efi.c
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+++ b/arch/x86/platform/efi/efi.c
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@@ -85,9 +85,10 @@ int efi_enabled(int facility)
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}
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EXPORT_SYMBOL(efi_enabled);
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+static bool disable_runtime = false;
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static int __init setup_noefi(char *arg)
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{
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- clear_bit(EFI_RUNTIME_SERVICES, &x86_efi_facility);
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+ disable_runtime = true;
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return 0;
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}
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early_param("noefi", setup_noefi);
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@@ -734,7 +735,7 @@ void __init efi_init(void)
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if (!efi_is_native())
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pr_info("No EFI runtime due to 32/64-bit mismatch with kernel\n");
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else {
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- if (efi_runtime_init())
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+ if (disable_runtime || efi_runtime_init())
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return;
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set_bit(EFI_RUNTIME_SERVICES, &x86_efi_facility);
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}
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