3.2-stable review patch. If anyone has any objections, please let me know.
------------------
From: Matt Fleming <matt.fleming@xxxxxxxxx>
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 <walt0924@xxxxxxxxx>
Cc: Satoru Takeuchi <takeuchi_satoru@xxxxxxxxxxxxxx>
Signed-off-by: Matt Fleming <matt.fleming@xxxxxxxxx>
Link: http://lkml.kernel.org/r/1361392572-25657-1-git-send-email-matt@xxxxxxxxxxxxxxxxx
Signed-off-by: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx>
[bwh: Backported to 3.2: efi_runtime_init() is not a separate function,
so put a whole set of statements in an if (!disable_runtime) block]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -83,9 +83,10 @@ 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);
@@ -549,35 +550,37 @@ void __init efi_init(void)
set_bit(EFI_CONFIG_TABLES, &x86_efi_facility);
- /*
- * Check out the runtime services table. We need to map
- * the runtime services table so that we can grab the physical
- * address of several of the EFI runtime functions, needed to
- * set the firmware into virtual mode.
- */
- runtime = early_ioremap((unsigned long)efi.systab->runtime,
- sizeof(efi_runtime_services_t));
- if (runtime != NULL) {
- /*
- * We will only need *early* access to the following
- * two EFI runtime services before set_virtual_address_map
- * is invoked.
- */
- efi_phys.get_time = (efi_get_time_t *)runtime->get_time;
- efi_phys.set_virtual_address_map =
- (efi_set_virtual_address_map_t *)
- runtime->set_virtual_address_map;
+ if (!disable_runtime) {
/*
- * Make efi_get_time can be called before entering
- * virtual mode.
+ * Check out the runtime services table. We need to map
+ * the runtime services table so that we can grab the physical
+ * address of several of the EFI runtime functions, needed to
+ * set the firmware into virtual mode.
*/
- efi.get_time = phys_efi_get_time;
-
- set_bit(EFI_RUNTIME_SERVICES, &x86_efi_facility);
- } else
- printk(KERN_ERR "Could not map the EFI runtime service "
- "table!\n");
- early_iounmap(runtime, sizeof(efi_runtime_services_t));
+ runtime = early_ioremap((unsigned long)efi.systab->runtime,
+ sizeof(efi_runtime_services_t));
+ if (runtime != NULL) {
+ /*
+ * We will only need *early* access to the following
+ * two EFI runtime services before set_virtual_address_map
+ * is invoked.
+ */
+ efi_phys.get_time = (efi_get_time_t *)runtime->get_time;
+ efi_phys.set_virtual_address_map =
+ (efi_set_virtual_address_map_t *)
+ runtime->set_virtual_address_map;
+ /*
+ * Make efi_get_time can be called before entering
+ * virtual mode.
+ */
+ efi.get_time = phys_efi_get_time;
+
+ set_bit(EFI_RUNTIME_SERVICES, &x86_efi_facility);
+ } else
+ printk(KERN_ERR "Could not map the EFI runtime service "
+ "table!\n");
+ early_iounmap(runtime, sizeof(efi_runtime_services_t));
+ }
/* Map the EFI memory map */
memmap.map = early_ioremap((unsigned long)memmap.phys_map,
--
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