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 <richard@nod.at> Signed-off-by: Matt Fleming <matt.fleming@intel.com>

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 <richard@nod.at> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Richard Weinberger · Matt Fleming
1 parent 3668011d4a
Showing 2 changed files with 19 additions and 1 deletions Side-by-side Diff
Documentation/kernel-parameters.txt
arch/x86/platform/efi/efi.c
@@ -788,6 +788,12 @@
 	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.
  
@@ -113,7 +113,16 @@
 }
 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)
 {
 	unsigned long flags;
@@ -1137,7 +1146,10 @@
 	 */
  
 	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;
...	...	@@ -788,6 +788,12 @@
788	788	edd= [EDD]
789	789	Format: {"off" \| "on" \| "skip[mbr]"}
790	790
	791	+ efi_no_storage_paranoia [EFI; X86]
	792	+ Using this parameter you can use more than 50% of
	793	+ your efi variable storage. Use this parameter only if
	794	+ you are really sure that your UEFI does sane gc and
	795	+ fulfills the spec otherwise your board may brick.
	796	+
791	797	eisa_irq_edge= [PARISC,HW]
792	798	See header of drivers/parisc/eisa.c.
793	799
...	...	@@ -113,7 +113,16 @@
113	113	}
114	114	early_param("add_efi_memmap", setup_add_efi_memmap);
115	115
	116	+static bool efi_no_storage_paranoia;
116	117
	118	+static int __init setup_storage_paranoia(char *arg)
	119	+{
	120	+ efi_no_storage_paranoia = true;
	121	+ return 0;
	122	+}
	123	+early_param("efi_no_storage_paranoia", setup_storage_paranoia);
	124	+
	125	+
117	126	static efi_status_t virt_efi_get_time(efi_time_t tm, efi_time_cap_t tc)
118	127	{
119	128	unsigned long flags;
...	...	@@ -1137,7 +1146,10 @@
1137	1146	*/
1138	1147
1139	1148	if (!storage_size \|\| size > remaining_size \|\|
1140		- (max_size && size > max_size) \|\|
	1149	+ (max_size && size > max_size))
	1150	+ return EFI_OUT_OF_RESOURCES;
	1151	+
	1152	+ if (!efi_no_storage_paranoia &&
1141	1153	((active_size + size + VAR_METADATA_SIZE > storage_size / 2) &&
1142	1154	(remaining_size - size < storage_size / 2)))
1143	1155	return EFI_OUT_OF_RESOURCES;