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>
This commit is contained in:
Seth Forshee 2013-03-07 11:40:17 -06:00 committed by Matt Fleming
parent f6161aa153
commit ed9dc8ce7a
2 changed files with 29 additions and 44 deletions

View file

@ -53,6 +53,15 @@ config EFI_VARS
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

View file

@ -1309,9 +1309,7 @@ static const struct inode_operations efivarfs_dir_inode_operations = {
.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 @@ static int efi_pstore_erase(enum pstore_type_id type, u64 id, int count,
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 @@ static struct pstore_info efi_pstore_info = {
.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 @@ int register_efivars(struct efivars *efivars,
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);