Hi Linus,
A collection of minor fixes, more EFI variables paranoia
(anti-bricking) plus the ability to disable the pstore either as a
runtime default or completely, due to bricking concerns.
The following changes since commit a937536b868b8369b98967929045f1df54234323:
Linux 3.9-rc3 (2013-03-17 15:59:32 -0700)
are available in the git repository at:
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86/urgent
for you to fetch changes up to b9726d9df8263fe756d2293ff01906f41f7d2776:
Merge tag 'efi-for-3.9-rc4' into x86/urgent (2013-03-23 21:49:51 -0700)
----------------------------------------------------------------
Ben Hutchings (1):
efivars: Fix check for CONFIG_EFI_VARS_PSTORE_DEFAULT_DISABLE
CQ Tang (1):
x86-64: Fix the failure case in copy_user_handle_tail()
Fenghua Yu (1):
x86-32, microcode_intel_early: Fix crash with CONFIG_DEBUG_VIRTUAL
H. Peter Anvin (3):
x86, microcode_intel_early: Mark apply_microcode_early() as cpuinit
Merge tag 'efi-for-3.9-rc3' into x86/urgent
Merge tag 'efi-for-3.9-rc4' into x86/urgent
Matt Fleming (2):
efivars: explicitly calculate length of VariableName
efivars: Handle duplicate names from get_next_variable()
Seth Forshee (2):
efivars: Allow disabling use as a pstore backend
efivars: Add module parameter to disable use as a pstore backend
arch/x86/kernel/microcode_intel_early.c | 30 +++----
arch/x86/lib/usercopy_64.c | 4 +-
drivers/firmware/Kconfig | 18 ++++
drivers/firmware/efivars.c | 150 ++++++++++++++++++++++----------
4 files changed, 139 insertions(+), 63 deletions(-)
diff --git a/arch/x86/kernel/microcode_intel_early.c b/arch/x86/kernel/microcode_intel_early.c
index 7890bc8..d893e8e 100644
--- a/arch/x86/kernel/microcode_intel_early.c
+++ b/arch/x86/kernel/microcode_intel_early.c
@@ -90,13 +90,13 @@ microcode_phys(struct microcode_intel **mc_saved_tmp,
struct microcode_intel ***mc_saved;
mc_saved = (struct microcode_intel ***)
- __pa_symbol(&mc_saved_data->mc_saved);
+ __pa_nodebug(&mc_saved_data->mc_saved);
for (i = 0; i < mc_saved_data->mc_saved_count; i++) {
struct microcode_intel *p;
p = *(struct microcode_intel **)
- __pa(mc_saved_data->mc_saved + i);
- mc_saved_tmp[i] = (struct microcode_intel *)__pa(p);
+ __pa_nodebug(mc_saved_data->mc_saved + i);
+ mc_saved_tmp[i] = (struct microcode_intel *)__pa_nodebug(p);
}
}
#endif
@@ -562,7 +562,7 @@ scan_microcode(unsigned long start, unsigned long end,
struct cpio_data cd;
long offset = 0;
#ifdef CONFIG_X86_32
- char *p = (char *)__pa_symbol(ucode_name);
+ char *p = (char *)__pa_nodebug(ucode_name);
#else
char *p = ucode_name;
#endif
@@ -630,8 +630,8 @@ static void __cpuinit print_ucode(struct ucode_cpu_info *uci)
if (mc_intel == NULL)
return;
- delay_ucode_info_p = (int *)__pa_symbol(&delay_ucode_info);
- current_mc_date_p = (int *)__pa_symbol(¤t_mc_date);
+ delay_ucode_info_p = (int *)__pa_nodebug(&delay_ucode_info);
+ current_mc_date_p = (int *)__pa_nodebug(¤t_mc_date);
*delay_ucode_info_p = 1;
*current_mc_date_p = mc_intel->hdr.date;
@@ -659,8 +659,8 @@ static inline void __cpuinit print_ucode(struct ucode_cpu_info *uci)
}
#endif
-static int apply_microcode_early(struct mc_saved_data *mc_saved_data,
- struct ucode_cpu_info *uci)
+static int __cpuinit apply_microcode_early(struct mc_saved_data *mc_saved_data,
+ struct ucode_cpu_info *uci)
{
struct microcode_intel *mc_intel;
unsigned int val[2];
@@ -741,15 +741,15 @@ load_ucode_intel_bsp(void)
#ifdef CONFIG_X86_32
struct boot_params *boot_params_p;
- boot_params_p = (struct boot_params *)__pa_symbol(&boot_params);
+ boot_params_p = (struct boot_params *)__pa_nodebug(&boot_params);
ramdisk_image = boot_params_p->hdr.ramdisk_image;
ramdisk_size = boot_params_p->hdr.ramdisk_size;
initrd_start_early = ramdisk_image;
initrd_end_early = initrd_start_early + ramdisk_size;
_load_ucode_intel_bsp(
- (struct mc_saved_data *)__pa_symbol(&mc_saved_data),
- (unsigned long *)__pa_symbol(&mc_saved_in_initrd),
+ (struct mc_saved_data *)__pa_nodebug(&mc_saved_data),
+ (unsigned long *)__pa_nodebug(&mc_saved_in_initrd),
initrd_start_early, initrd_end_early, &uci);
#else
ramdisk_image = boot_params.hdr.ramdisk_image;
@@ -772,10 +772,10 @@ void __cpuinit load_ucode_intel_ap(void)
unsigned long *initrd_start_p;
mc_saved_in_initrd_p =
- (unsigned long *)__pa_symbol(mc_saved_in_initrd);
- mc_saved_data_p = (struct mc_saved_data *)__pa_symbol(&mc_saved_data);
- initrd_start_p = (unsigned long *)__pa_symbol(&initrd_start);
- initrd_start_addr = (unsigned long)__pa_symbol(*initrd_start_p);
+ (unsigned long *)__pa_nodebug(mc_saved_in_initrd);
+ mc_saved_data_p = (struct mc_saved_data *)__pa_nodebug(&mc_saved_data);
+ initrd_start_p = (unsigned long *)__pa_nodebug(&initrd_start);
+ initrd_start_addr = (unsigned long)__pa_nodebug(*initrd_start_p);
#else
mc_saved_data_p = &mc_saved_data;
mc_saved_in_initrd_p = mc_saved_in_initrd;
diff --git a/arch/x86/lib/usercopy_64.c b/arch/x86/lib/usercopy_64.c
index 05928aa..906fea3 100644
--- a/arch/x86/lib/usercopy_64.c
+++ b/arch/x86/lib/usercopy_64.c
@@ -74,10 +74,10 @@ copy_user_handle_tail(char *to, char *from, unsigned len, unsigned zerorest)
char c;
unsigned zero_len;
- for (; len; --len) {
+ for (; len; --len, to++) {
if (__get_user_nocheck(c, from++, sizeof(char)))
break;
- if (__put_user_nocheck(c, to++, sizeof(char)))
+ if (__put_user_nocheck(c, to, sizeof(char)))
break;
}
diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
index 9b00072..42c759a 100644
--- a/drivers/firmware/Kconfig
+++ b/drivers/firmware/Kconfig
@@ -53,6 +53,24 @@ 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_VARS_PSTORE_DEFAULT_DISABLE
+ bool "Disable using efivars as a pstore backend by default"
+ depends on EFI_VARS_PSTORE
+ default n
+ help
+ Saying Y here will disable the use of efivars as a storage
+ backend for pstore by default. This setting can be overridden
+ using the efivars module's pstore_disable parameter.
+
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..7acafb8 100644
--- a/drivers/firmware/efivars.c
+++ b/drivers/firmware/efivars.c
@@ -103,6 +103,11 @@ MODULE_VERSION(EFIVARS_VERSION);
*/
#define GUID_LEN 36
+static bool efivars_pstore_disable =
+ IS_ENABLED(CONFIG_EFI_VARS_PSTORE_DEFAULT_DISABLE);
+
+module_param_named(pstore_disable, efivars_pstore_disable, bool, 0644);
+
/*
* The maximum size of VariableName + Data = 1024
* Therefore, it's reasonable to save that much
@@ -165,6 +170,7 @@ efivar_create_sysfs_entry(struct efivars *efivars,
static void efivar_update_sysfs_entries(struct work_struct *);
static DECLARE_WORK(efivar_work, efivar_update_sysfs_entries);
+static bool efivar_wq_enabled = true;
/* Return the number of unicode characters in data */
static unsigned long
@@ -1309,9 +1315,7 @@ 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)
{
@@ -1441,7 +1445,7 @@ static int efi_pstore_write(enum pstore_type_id type,
spin_unlock_irqrestore(&efivars->lock, flags);
- if (reason == KMSG_DUMP_OOPS)
+ if (reason == KMSG_DUMP_OOPS && efivar_wq_enabled)
schedule_work(&efivar_work);
*id = part;
@@ -1514,38 +1518,6 @@ 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 +1529,24 @@ 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)
@@ -1716,6 +1706,31 @@ static bool variable_is_present(efi_char16_t *variable_name, efi_guid_t *vendor)
return found;
}
+/*
+ * Returns the size of variable_name, in bytes, including the
+ * terminating NULL character, or variable_name_size if no NULL
+ * character is found among the first variable_name_size bytes.
+ */
+static unsigned long var_name_strnsize(efi_char16_t *variable_name,
+ unsigned long variable_name_size)
+{
+ unsigned long len;
+ efi_char16_t c;
+
+ /*
+ * The variable name is, by definition, a NULL-terminated
+ * string, so make absolutely sure that variable_name_size is
+ * the value we expect it to be. If not, return the real size.
+ */
+ for (len = 2; len <= variable_name_size; len += sizeof(c)) {
+ c = variable_name[(len / sizeof(c)) - 1];
+ if (!c)
+ break;
+ }
+
+ return min(len, variable_name_size);
+}
+
static void efivar_update_sysfs_entries(struct work_struct *work)
{
struct efivars *efivars = &__efivars;
@@ -1756,10 +1771,13 @@ static void efivar_update_sysfs_entries(struct work_struct *work)
if (!found) {
kfree(variable_name);
break;
- } else
+ } else {
+ variable_name_size = var_name_strnsize(variable_name,
+ variable_name_size);
efivar_create_sysfs_entry(efivars,
variable_name_size,
variable_name, &vendor);
+ }
}
}
@@ -1958,6 +1976,35 @@ void unregister_efivars(struct efivars *efivars)
}
EXPORT_SYMBOL_GPL(unregister_efivars);
+/*
+ * Print a warning when duplicate EFI variables are encountered and
+ * disable the sysfs workqueue since the firmware is buggy.
+ */
+static void dup_variable_bug(efi_char16_t *s16, efi_guid_t *vendor_guid,
+ unsigned long len16)
+{
+ size_t i, len8 = len16 / sizeof(efi_char16_t);
+ char *s8;
+
+ /*
+ * Disable the workqueue since the algorithm it uses for
+ * detecting new variables won't work with this buggy
+ * implementation of GetNextVariableName().
+ */
+ efivar_wq_enabled = false;
+
+ s8 = kzalloc(len8, GFP_KERNEL);
+ if (!s8)
+ return;
+
+ for (i = 0; i < len8; i++)
+ s8[i] = s16[i];
+
+ printk(KERN_WARNING "efivars: duplicate variable: %s-%pUl\n",
+ s8, vendor_guid);
+ kfree(s8);
+}
+
int register_efivars(struct efivars *efivars,
const struct efivar_operations *ops,
struct kobject *parent_kobj)
@@ -2006,6 +2053,24 @@ int register_efivars(struct efivars *efivars,
&vendor_guid);
switch (status) {
case EFI_SUCCESS:
+ variable_name_size = var_name_strnsize(variable_name,
+ variable_name_size);
+
+ /*
+ * Some firmware implementations return the
+ * same variable name on multiple calls to
+ * get_next_variable(). Terminate the loop
+ * immediately as there is no guarantee that
+ * we'll ever see a different variable name,
+ * and may end up looping here forever.
+ */
+ if (variable_is_present(variable_name, &vendor_guid)) {
+ dup_variable_bug(variable_name, &vendor_guid,
+ variable_name_size);
+ status = EFI_NOT_FOUND;
+ break;
+ }
+
efivar_create_sysfs_entry(efivars,
variable_name_size,
variable_name,
@@ -2025,15 +2090,8 @@ 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);
- }
+ if (!efivars_pstore_disable)
+ efivar_pstore_register(efivars);
register_filesystem(&efivarfs_type);