From 8c58bf3eec3b8fc8162fe557e9361891c20758f2 Mon Sep 17 00:00:00 2001 From: Richard Weinberger Date: Wed, 17 Apr 2013 01:00:53 +0200 Subject: [PATCH] x86,efi: Implement efi_no_storage_paranoia parameter Using this parameter one can disable the storage_size/2 check if he is really sure that the UEFI does sane gc and fulfills the spec. This parameter is useful if a devices uses more than 50% of the storage by default. The Intel DQSW67 desktop board is such a sucker for exmaple. Signed-off-by: Richard Weinberger Signed-off-by: Matt Fleming --- Documentation/kernel-parameters.txt | 6 ++++++ arch/x86/platform/efi/efi.c | 14 +++++++++++++- 2 files changed, 19 insertions(+), 1 deletion(-) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 4609e81dbc37..d1cc3a9fa14f 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -788,6 +788,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted. edd= [EDD] Format: {"off" | "on" | "skip[mbr]"} + efi_no_storage_paranoia [EFI; X86] + Using this parameter you can use more than 50% of + your efi variable storage. Use this parameter only if + you are really sure that your UEFI does sane gc and + fulfills the spec otherwise your board may brick. + eisa_irq_edge= [PARISC,HW] See header of drivers/parisc/eisa.c. diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c index 4f364c7c6111..e4a86a677ce1 100644 --- a/arch/x86/platform/efi/efi.c +++ b/arch/x86/platform/efi/efi.c @@ -113,6 +113,15 @@ static int __init setup_add_efi_memmap(char *arg) } early_param("add_efi_memmap", setup_add_efi_memmap); +static bool efi_no_storage_paranoia; + +static int __init setup_storage_paranoia(char *arg) +{ + efi_no_storage_paranoia = true; + return 0; +} +early_param("efi_no_storage_paranoia", setup_storage_paranoia); + static efi_status_t virt_efi_get_time(efi_time_t *tm, efi_time_cap_t *tc) { @@ -1137,7 +1146,10 @@ efi_status_t efi_query_variable_store(u32 attributes, unsigned long size) */ if (!storage_size || size > remaining_size || - (max_size && size > max_size) || + (max_size && size > max_size)) + return EFI_OUT_OF_RESOURCES; + + if (!efi_no_storage_paranoia && ((active_size + size + VAR_METADATA_SIZE > storage_size / 2) && (remaining_size - size < storage_size / 2))) return EFI_OUT_OF_RESOURCES;