efivars: Allow disabling use as a pstore backend
Add a new option, CONFIG_EFI_VARS_PSTORE, which can be set to N to
avoid using efivars as a backend to pstore, as some users may want to
compile out the code completely.
Set the default to Y to maintain backwards compatability, since this
feature has always been enabled until now.
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Cc: Josh Boyer <jwboyer@redhat.com>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Seiji Aguchi <seiji.aguchi@hds.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
index 9b00072..898023d 100644
--- a/drivers/firmware/Kconfig
+++ b/drivers/firmware/Kconfig
@@ -53,6 +53,15 @@
Subsequent efibootmgr releases may be found at:
<http://linux.dell.com/efibootmgr>
+config EFI_VARS_PSTORE
+ bool "Register efivars backend for pstore"
+ depends on EFI_VARS && PSTORE
+ default y
+ help
+ Say Y here to enable use efivars as a backend to pstore. This
+ will allow writing console messages, crash dumps, or anything
+ else supported by pstore to EFI variables.
+
config EFI_PCDP
bool "Console device selection via EFI PCDP or HCDP table"
depends on ACPI && EFI && IA64
diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c
index fe62aa3..37b6f24 100644
--- a/drivers/firmware/efivars.c
+++ b/drivers/firmware/efivars.c
@@ -1309,9 +1309,7 @@
.create = efivarfs_create,
};
-static struct pstore_info efi_pstore_info;
-
-#ifdef CONFIG_PSTORE
+#ifdef CONFIG_EFI_VARS_PSTORE
static int efi_pstore_open(struct pstore_info *psi)
{
@@ -1514,38 +1512,6 @@
return 0;
}
-#else
-static int efi_pstore_open(struct pstore_info *psi)
-{
- return 0;
-}
-
-static int efi_pstore_close(struct pstore_info *psi)
-{
- return 0;
-}
-
-static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type, int *count,
- struct timespec *timespec,
- char **buf, struct pstore_info *psi)
-{
- return -1;
-}
-
-static int efi_pstore_write(enum pstore_type_id type,
- enum kmsg_dump_reason reason, u64 *id,
- unsigned int part, int count, size_t size,
- struct pstore_info *psi)
-{
- return 0;
-}
-
-static int efi_pstore_erase(enum pstore_type_id type, u64 id, int count,
- struct timespec time, struct pstore_info *psi)
-{
- return 0;
-}
-#endif
static struct pstore_info efi_pstore_info = {
.owner = THIS_MODULE,
@@ -1557,6 +1523,24 @@
.erase = efi_pstore_erase,
};
+static void efivar_pstore_register(struct efivars *efivars)
+{
+ efivars->efi_pstore_info = efi_pstore_info;
+ efivars->efi_pstore_info.buf = kmalloc(4096, GFP_KERNEL);
+ if (efivars->efi_pstore_info.buf) {
+ efivars->efi_pstore_info.bufsize = 1024;
+ efivars->efi_pstore_info.data = efivars;
+ spin_lock_init(&efivars->efi_pstore_info.buf_lock);
+ pstore_register(&efivars->efi_pstore_info);
+ }
+}
+#else
+static void efivar_pstore_register(struct efivars *efivars)
+{
+ return;
+}
+#endif
+
static ssize_t efivar_create(struct file *filp, struct kobject *kobj,
struct bin_attribute *bin_attr,
char *buf, loff_t pos, size_t count)
@@ -2025,15 +2009,7 @@
if (error)
unregister_efivars(efivars);
- efivars->efi_pstore_info = efi_pstore_info;
-
- efivars->efi_pstore_info.buf = kmalloc(4096, GFP_KERNEL);
- if (efivars->efi_pstore_info.buf) {
- efivars->efi_pstore_info.bufsize = 1024;
- efivars->efi_pstore_info.data = efivars;
- spin_lock_init(&efivars->efi_pstore_info.buf_lock);
- pstore_register(&efivars->efi_pstore_info);
- }
+ efivar_pstore_register(efivars);
register_filesystem(&efivarfs_type);