Merge tag 'efi-next-for-v7.4' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi

Pull EFI updates from Ard Biesheuvel:

 - Set the LoaderDevicePartUUID EFI variable from the stub to help
   systemd discover the file system layout when booting straight into
   Linux without GRUB or systemd-boot (Vincent Mailhol)

 - Some GUID deduplication work from Vincent

 - Remove pointless UTF16->UTF8 and vice versa conversions from the stub

 - Some kmap() -> kmap_local_page() conversions in the capsule loader

 - Add a runtime control to en/disable EFI runtime services so that
   PREEMPT_RT systems can enable them as needed

 - Add a 'nostatfs' mount option to efivarfs so that the cost of
   querying the EFI variable store (which is already rate limited) can
   be avoided entirely on systems where it is disproportionately costly

 - Rework the EFI libstub Makefile to align x86 with other
   architectures, and inherit/adapt the global CFLAGS variable rather
   than reconstruct it from scratch

 - Constify attributes of statically allocated sysfs nodes

 - Avoid register x18 when building the arm64 EFI stub, in order to
   comply with the UEFI spec, and to permit it to execute in a context
   where x18 is special

 - Preserve the physical addresses of all EFI config tables that may be
   of interest to an incoming kexec kernel

 - Add some LKDTM tests for EFI runtime crashes where the faulting
   address is inside a EFI memory region

 - Other minor bug fixes and cosmetic cleanups

* tag 'efi-next-for-v7.4' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi: (35 commits)
  lkdtm: Add more EFI runtime tests
  efi: Initialize all configuration table addresses to EFI_INVALID_TABLE_ADDR
  efi: Retain the address of the LINUX_EFI_MEMRESERVE table
  efi/libstub: Don't replace an existing LINUX_EFI_MEMRESERVE table
  efi/runtime-wrappers: Don't park the worker after a recovered firmware fault
  efi: Use sysfs_emit() not sprintf() to generate sysfs file contents
  efi: Constify sysfs attributes
  efi/libstub: Disable kernel stack erasing in the common flags
  efi/libstub: Build the x86 stub from KBUILD_CFLAGS
  efi/libstub: Declare the x86 stub's assembly entry points
  efi/libstub: arm64: Don't use the platform register x18
  efi/libstub: Free cmdline_ptr in efi_pe_entry
  efi/riscv: libstub: Don't set image_size in handle_kernel_image()
  efi/libstub: Fix error unwind freeing fdt in allocate_new_fdt_and_exit_boot()
  efivarfs: add nostatfs mount option to skip QueryVariableInfo()
  efi/libstub: add initial Boot Loader Interface support
  efi/libstub: Add efi_snprintf() to construct wide strings
  efi/libstub: Add support for printing human readable GUIDs
  efi/libstub: Output UTF-16 directly from vsnprintf()
  efi/libstub: Avoid efi_puts() for compile time constant strings
  ...

2 files changed, 46 insertions, 2 deletions

diff --git a/include/linux/efi.h b/include/linux/efi.h
index aa15ff88539b..cc1df1577d5f 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -631,6 +631,8 @@ typedef struct {
 
 extern unsigned long __ro_after_init efi_rng_seed;		/* RNG Seed table */
 
+enum efi_rts_ids;
+
 /*
  * All runtime access to EFI goes through this structure:
  */
@@ -650,6 +652,7 @@ extern struct efi {
 	unsigned long			mokvar_table;		/* MOK variable config table */
 	unsigned long			coco_secret;		/* Confidential computing secret table */
 	unsigned long			unaccepted;		/* Unaccepted memory table */
+	unsigned long			mem_reserve;		/* Persistent memory reservations */
 
 	efi_get_time_t			*get_time;
 	efi_set_time_t			*set_time;
@@ -666,6 +669,10 @@ extern struct efi {
 	efi_get_next_high_mono_count_t	*get_next_high_mono_count;
 	efi_reset_system_t		*reset_system;
 
+#if IS_ENABLED(CONFIG_LKDTM)
+	efi_status_t			(*lkdtm_rt_test)(enum efi_rts_ids id);
+#endif
+
 	struct efi_memory_map		memmap;
 	unsigned long			flags;
 } efi;
@@ -957,6 +964,17 @@ extern int efi_status_to_err(efi_status_t status);
 #define   EFI_DEV_END_INSTANCE			0x01
 #define   EFI_DEV_END_ENTIRE			0xFF
 
+enum efi_hd_partition_format {
+	EFI_HD_PARTITION_FORMAT_MBR = 1,
+	EFI_HD_PARTITION_FORMAT_GPT,
+};
+
+enum efi_hd_signature_type {
+	EFI_HD_SIGNATURE_TYPE_NONE,
+	EFI_HD_SIGNATURE_TYPE_MBR,
+	EFI_HD_SIGNATURE_TYPE_GUID,
+};
+
 struct efi_generic_dev_path {
 	u8				type;
 	u8				sub_type;
@@ -988,6 +1006,16 @@ struct efi_rel_offset_dev_path {
 	u64				ending_offset;
 } __packed;
 
+struct efi_hd_dev_path {
+	struct efi_generic_dev_path	header;
+	u32				partition_number;
+	u64				partition_start;
+	u64				partition_size;
+	efi_guid_t			signature;
+	u8				partition_format;
+	u8				signature_type;
+} __packed;
+
 struct efi_mem_mapped_dev_path {
 	struct efi_generic_dev_path	header;
 	u32				memory_type;
@@ -1007,6 +1035,7 @@ struct efi_dev_path {
 		struct efi_pci_dev_path		pci;
 		struct efi_vendor_dev_path	vendor;
 		struct efi_rel_offset_dev_path	rel_offset;
+		struct efi_hd_dev_path		hd;
 	};
 } __packed;
 
@@ -1109,6 +1138,7 @@ extern void efi_call_virt_check_flags(unsigned long flags, const void *caller);
 extern unsigned long efi_call_virt_save_flags(void);
 
 void efi_runtime_assert_lock_held(void);
+efi_status_t efi_runtime_set_enable_flag(bool enable);
 
 enum efi_secureboot_mode {
 	efi_secureboot_mode_unset,
@@ -1230,6 +1260,10 @@ enum efi_rts_ids {
 	EFI_UPDATE_CAPSULE,
 	EFI_QUERY_CAPSULE_CAPS,
 	EFI_ACPI_PRM_HANDLER,
+#if IS_ENABLED(CONFIG_LKDTM)
+	EFI_LKDTM_RUNTIME_RO_TEST,
+	EFI_LKDTM_RUNTIME_NX_TEST,
+#endif
 };
 
 union efi_rts_args;
@@ -1330,7 +1364,8 @@ bool efi_config_table_is_usable(const efi_guid_t *guid, unsigned long table)
 	return xen_efi_config_table_is_usable(guid, table);
 }
 
-umode_t efi_attr_is_visible(struct kobject *kobj, struct attribute *attr, int n);
+umode_t efi_attr_is_visible(struct kobject *kobj, const struct attribute *attr,
+			    int n);
 
 int ovmf_log_probe(unsigned long ovmf_debug_log_table);
 
diff --git a/include/linux/ucs2_string.h b/include/linux/ucs2_string.h
index c499ae809c7d..74f23ca5a967 100644
--- a/include/linux/ucs2_string.h
+++ b/include/linux/ucs2_string.h
@@ -14,7 +14,16 @@ ssize_t ucs2_strscpy(ucs2_char_t *dst, const ucs2_char_t *src, size_t count);
 int ucs2_strncmp(const ucs2_char_t *a, const ucs2_char_t *b, size_t len);
 
 unsigned long ucs2_utf8size(const ucs2_char_t *src);
+unsigned long
+ucs2_as_utf8_l(u8 *dest, const ucs2_char_t *src, unsigned long limit,
+	       unsigned long maxlength);
+
+static inline
 unsigned long ucs2_as_utf8(u8 *dest, const ucs2_char_t *src,
-			   unsigned long maxlength);
+			   unsigned long maxlength)
+{
+	return ucs2_as_utf8_l(dest, src, ucs2_strnlen(src, maxlength),
+			      maxlength);
+}
 
 #endif /* _LINUX_UCS2_STRING_H_ */