diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2024-01-10 04:11:27 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2024-01-10 04:11:27 +0300 |
commit | a7e4c6cf5bbbd8fea2be1cef0540e5cf107c43c2 (patch) | |
tree | 6ec2ede8139aaacdd034a8a84c92174269a87f36 /drivers | |
parent | 7c6a3fc925b63d5201f1c11b93193d8a466a7d89 (diff) | |
parent | 4afa688d7141ae7a166d32224abbfd536acccfca (diff) | |
download | linux-a7e4c6cf5bbbd8fea2be1cef0540e5cf107c43c2.tar.xz |
Merge tag 'efi-next-for-v6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi
Pull EFI updates from Ard Biesheuvel:
- Fix a syzbot reported issue in efivarfs where concurrent accesses to
the file system resulted in list corruption
- Add support for accessing EFI variables via the TEE subsystem (and a
trusted application in the secure world) instead of via EFI runtime
firmware running in the OS's execution context
- Avoid linker tricks to discover the image base on LoongArch
* tag 'efi-next-for-v6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
efi: memmap: fix kernel-doc warnings
efi/loongarch: Directly position the loaded image file
efivarfs: automatically update super block flag
efi: Add tee-based EFI variable driver
efi: Add EFI_ACCESS_DENIED status code
efi: expose efivar generic ops register function
efivarfs: Move efivarfs list into superblock s_fs_info
efivarfs: Free s_fs_info on unmount
efivarfs: Move efivar availability check into FS context init
efivarfs: force RO when remounting if SetVariable is not supported
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/firmware/efi/Kconfig | 15 | ||||
-rw-r--r-- | drivers/firmware/efi/Makefile | 1 | ||||
-rw-r--r-- | drivers/firmware/efi/efi.c | 18 | ||||
-rw-r--r-- | drivers/firmware/efi/libstub/loongarch-stub.c | 9 | ||||
-rw-r--r-- | drivers/firmware/efi/libstub/loongarch-stub.h | 4 | ||||
-rw-r--r-- | drivers/firmware/efi/libstub/loongarch.c | 6 | ||||
-rw-r--r-- | drivers/firmware/efi/memmap.c | 8 | ||||
-rw-r--r-- | drivers/firmware/efi/stmm/mm_communication.h | 236 | ||||
-rw-r--r-- | drivers/firmware/efi/stmm/tee_stmm_efi.c | 616 | ||||
-rw-r--r-- | drivers/firmware/efi/vars.c | 8 |
10 files changed, 912 insertions, 9 deletions
diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig index cb374b2da9b7..72f2537d90ca 100644 --- a/drivers/firmware/efi/Kconfig +++ b/drivers/firmware/efi/Kconfig @@ -301,3 +301,18 @@ config UEFI_CPER_X86 bool depends on UEFI_CPER && X86 default y + +config TEE_STMM_EFI + tristate "TEE-based EFI runtime variable service driver" + depends on EFI && OPTEE + help + Select this config option if TEE is compiled to include StandAloneMM + as a separate secure partition. It has the ability to check and store + EFI variables on an RPMB or any other non-volatile medium used by + StandAloneMM. + + Enabling this will change the EFI runtime services from the firmware + provided functions to TEE calls. + + To compile this driver as a module, choose M here: the module + will be called tee_stmm_efi. diff --git a/drivers/firmware/efi/Makefile b/drivers/firmware/efi/Makefile index e489fefd23da..a2d0009560d0 100644 --- a/drivers/firmware/efi/Makefile +++ b/drivers/firmware/efi/Makefile @@ -42,3 +42,4 @@ obj-$(CONFIG_EFI_EARLYCON) += earlycon.o obj-$(CONFIG_UEFI_CPER_ARM) += cper-arm.o obj-$(CONFIG_UEFI_CPER_X86) += cper-x86.o obj-$(CONFIG_UNACCEPTED_MEMORY) += unaccepted_memory.o +obj-$(CONFIG_TEE_STMM_EFI) += stmm/tee_stmm_efi.o diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index 9d3910d1abe1..4fcda50acfa4 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -32,6 +32,7 @@ #include <linux/ucs2_string.h> #include <linux/memblock.h> #include <linux/security.h> +#include <linux/notifier.h> #include <asm/early_ioremap.h> @@ -187,6 +188,9 @@ static const struct attribute_group efi_subsys_attr_group = { .is_visible = efi_attr_is_visible, }; +struct blocking_notifier_head efivar_ops_nh; +EXPORT_SYMBOL_GPL(efivar_ops_nh); + static struct efivars generic_efivars; static struct efivar_operations generic_ops; @@ -231,6 +235,18 @@ static void generic_ops_unregister(void) efivars_unregister(&generic_efivars); } +void efivars_generic_ops_register(void) +{ + generic_ops_register(); +} +EXPORT_SYMBOL_GPL(efivars_generic_ops_register); + +void efivars_generic_ops_unregister(void) +{ + generic_ops_unregister(); +} +EXPORT_SYMBOL_GPL(efivars_generic_ops_unregister); + #ifdef CONFIG_EFI_CUSTOM_SSDT_OVERLAYS #define EFIVAR_SSDT_NAME_MAX 16UL static char efivar_ssdt[EFIVAR_SSDT_NAME_MAX] __initdata; @@ -419,6 +435,8 @@ static int __init efisubsys_init(void) platform_device_register_simple("efivars", 0, NULL, 0); } + BLOCKING_INIT_NOTIFIER_HEAD(&efivar_ops_nh); + error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group); if (error) { pr_err("efi: Sysfs attribute export failed with error %d.\n", diff --git a/drivers/firmware/efi/libstub/loongarch-stub.c b/drivers/firmware/efi/libstub/loongarch-stub.c index d6ec5d4b8dbe..736b6aae323d 100644 --- a/drivers/firmware/efi/libstub/loongarch-stub.c +++ b/drivers/firmware/efi/libstub/loongarch-stub.c @@ -8,10 +8,10 @@ #include <asm/efi.h> #include <asm/addrspace.h> #include "efistub.h" +#include "loongarch-stub.h" extern int kernel_asize; extern int kernel_fsize; -extern int kernel_offset; extern int kernel_entry; efi_status_t handle_kernel_image(unsigned long *image_addr, @@ -24,7 +24,7 @@ efi_status_t handle_kernel_image(unsigned long *image_addr, efi_status_t status; unsigned long kernel_addr = 0; - kernel_addr = (unsigned long)&kernel_offset - kernel_offset; + kernel_addr = (unsigned long)image->image_base; status = efi_relocate_kernel(&kernel_addr, kernel_fsize, kernel_asize, EFI_KIMG_PREFERRED_ADDRESS, efi_get_kimg_min_align(), 0x0); @@ -35,9 +35,10 @@ efi_status_t handle_kernel_image(unsigned long *image_addr, return status; } -unsigned long kernel_entry_address(unsigned long kernel_addr) +unsigned long kernel_entry_address(unsigned long kernel_addr, + efi_loaded_image_t *image) { - unsigned long base = (unsigned long)&kernel_offset - kernel_offset; + unsigned long base = (unsigned long)image->image_base; return (unsigned long)&kernel_entry - base + kernel_addr; } diff --git a/drivers/firmware/efi/libstub/loongarch-stub.h b/drivers/firmware/efi/libstub/loongarch-stub.h new file mode 100644 index 000000000000..cd015955a015 --- /dev/null +++ b/drivers/firmware/efi/libstub/loongarch-stub.h @@ -0,0 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +unsigned long kernel_entry_address(unsigned long kernel_addr, + efi_loaded_image_t *image); diff --git a/drivers/firmware/efi/libstub/loongarch.c b/drivers/firmware/efi/libstub/loongarch.c index 0e0aa6cda73f..684c9354637c 100644 --- a/drivers/firmware/efi/libstub/loongarch.c +++ b/drivers/firmware/efi/libstub/loongarch.c @@ -8,6 +8,7 @@ #include <asm/efi.h> #include <asm/addrspace.h> #include "efistub.h" +#include "loongarch-stub.h" typedef void __noreturn (*kernel_entry_t)(bool efi, unsigned long cmdline, unsigned long systab); @@ -37,7 +38,8 @@ static efi_status_t exit_boot_func(struct efi_boot_memmap *map, void *priv) return EFI_SUCCESS; } -unsigned long __weak kernel_entry_address(unsigned long kernel_addr) +unsigned long __weak kernel_entry_address(unsigned long kernel_addr, + efi_loaded_image_t *image) { return *(unsigned long *)(kernel_addr + 8) - VMLINUX_LOAD_ADDRESS + kernel_addr; } @@ -73,7 +75,7 @@ efi_status_t efi_boot_kernel(void *handle, efi_loaded_image_t *image, csr_write64(CSR_DMW0_INIT, LOONGARCH_CSR_DMWIN0); csr_write64(CSR_DMW1_INIT, LOONGARCH_CSR_DMWIN1); - real_kernel_entry = (void *)kernel_entry_address(kernel_addr); + real_kernel_entry = (void *)kernel_entry_address(kernel_addr, image); real_kernel_entry(true, (unsigned long)cmdline_ptr, (unsigned long)efi_system_table); diff --git a/drivers/firmware/efi/memmap.c b/drivers/firmware/efi/memmap.c index a1180461a445..3365944f7965 100644 --- a/drivers/firmware/efi/memmap.c +++ b/drivers/firmware/efi/memmap.c @@ -32,7 +32,7 @@ * space isn't setup. Once the kernel is fully booted we can fallback * to the more robust memremap*() API. * - * Returns zero on success, a negative error code on failure. + * Returns: zero on success, a negative error code on failure. */ int __init __efi_memmap_init(struct efi_memory_map_data *data) { @@ -77,6 +77,8 @@ int __init __efi_memmap_init(struct efi_memory_map_data *data) * * Use early_memremap() to map the passed in EFI memory map and assign * it to efi.memmap. + * + * Returns: zero on success, a negative error code on failure. */ int __init efi_memmap_init_early(struct efi_memory_map_data *data) { @@ -107,7 +109,7 @@ void __init efi_memmap_unmap(void) /** * efi_memmap_init_late - Map efi.memmap with memremap() - * @phys_addr: Physical address of the new EFI memory map + * @addr: Physical address of the new EFI memory map * @size: Size in bytes of the new EFI memory map * * Setup a mapping of the EFI memory map using ioremap_cache(). This @@ -126,7 +128,7 @@ void __init efi_memmap_unmap(void) * runtime so that things like efi_mem_desc_lookup() and * efi_mem_attributes() always work. * - * Returns zero on success, a negative error code on failure. + * Returns: zero on success, a negative error code on failure. */ int __init efi_memmap_init_late(phys_addr_t addr, unsigned long size) { diff --git a/drivers/firmware/efi/stmm/mm_communication.h b/drivers/firmware/efi/stmm/mm_communication.h new file mode 100644 index 000000000000..52a1f32cd1eb --- /dev/null +++ b/drivers/firmware/efi/stmm/mm_communication.h @@ -0,0 +1,236 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * Headers for EFI variable service via StandAloneMM, EDK2 application running + * in OP-TEE. Most of the structs and defines resemble the EDK2 naming. + * + * Copyright (c) 2017, Intel Corporation. All rights reserved. + * Copyright (C) 2020 Linaro Ltd. + */ + +#ifndef _MM_COMMUNICATION_H_ +#define _MM_COMMUNICATION_H_ + +/* + * Interface to the pseudo Trusted Application (TA), which provides a + * communication channel with the Standalone MM (Management Mode) + * Secure Partition running at Secure-EL0 + */ + +#define PTA_STMM_CMD_COMMUNICATE 0 + +/* + * Defined in OP-TEE, this UUID is used to identify the pseudo-TA. + * OP-TEE is using big endian GUIDs while UEFI uses little endian ones + */ +#define PTA_STMM_UUID \ + UUID_INIT(0xed32d533, 0x99e6, 0x4209, \ + 0x9c, 0xc0, 0x2d, 0x72, 0xcd, 0xd9, 0x98, 0xa7) + +#define EFI_MM_VARIABLE_GUID \ + EFI_GUID(0xed32d533, 0x99e6, 0x4209, \ + 0x9c, 0xc0, 0x2d, 0x72, 0xcd, 0xd9, 0x98, 0xa7) + +/** + * struct efi_mm_communicate_header - Header used for SMM variable communication + + * @header_guid: header use for disambiguation of content + * @message_len: length of the message. Does not include the size of the + * header + * @data: payload of the message + * + * Defined in the PI spec as EFI_MM_COMMUNICATE_HEADER. + * To avoid confusion in interpreting frames, the communication buffer should + * always begin with efi_mm_communicate_header. + */ +struct efi_mm_communicate_header { + efi_guid_t header_guid; + size_t message_len; + u8 data[]; +} __packed; + +#define MM_COMMUNICATE_HEADER_SIZE \ + (sizeof(struct efi_mm_communicate_header)) + +/* SPM return error codes */ +#define ARM_SVC_SPM_RET_SUCCESS 0 +#define ARM_SVC_SPM_RET_NOT_SUPPORTED -1 +#define ARM_SVC_SPM_RET_INVALID_PARAMS -2 +#define ARM_SVC_SPM_RET_DENIED -3 +#define ARM_SVC_SPM_RET_NO_MEMORY -5 + +#define SMM_VARIABLE_FUNCTION_GET_VARIABLE 1 +/* + * The payload for this function is + * SMM_VARIABLE_COMMUNICATE_GET_NEXT_VARIABLE_NAME. + */ +#define SMM_VARIABLE_FUNCTION_GET_NEXT_VARIABLE_NAME 2 +/* + * The payload for this function is SMM_VARIABLE_COMMUNICATE_ACCESS_VARIABLE. + */ +#define SMM_VARIABLE_FUNCTION_SET_VARIABLE 3 +/* + * The payload for this function is + * SMM_VARIABLE_COMMUNICATE_QUERY_VARIABLE_INFO. + */ +#define SMM_VARIABLE_FUNCTION_QUERY_VARIABLE_INFO 4 +/* + * It is a notify event, no extra payload for this function. + */ +#define SMM_VARIABLE_FUNCTION_READY_TO_BOOT 5 +/* + * It is a notify event, no extra payload for this function. + */ +#define SMM_VARIABLE_FUNCTION_EXIT_BOOT_SERVICE 6 +/* + * The payload for this function is VARIABLE_INFO_ENTRY. + * The GUID in EFI_SMM_COMMUNICATE_HEADER is gEfiSmmVariableProtocolGuid. + */ +#define SMM_VARIABLE_FUNCTION_GET_STATISTICS 7 +/* + * The payload for this function is SMM_VARIABLE_COMMUNICATE_LOCK_VARIABLE + */ +#define SMM_VARIABLE_FUNCTION_LOCK_VARIABLE 8 + +#define SMM_VARIABLE_FUNCTION_VAR_CHECK_VARIABLE_PROPERTY_SET 9 + +#define SMM_VARIABLE_FUNCTION_VAR_CHECK_VARIABLE_PROPERTY_GET 10 + +#define SMM_VARIABLE_FUNCTION_GET_PAYLOAD_SIZE 11 +/* + * The payload for this function is + * SMM_VARIABLE_COMMUNICATE_RUNTIME_VARIABLE_CACHE_CONTEXT + */ +#define SMM_VARIABLE_FUNCTION_INIT_RUNTIME_VARIABLE_CACHE_CONTEXT 12 + +#define SMM_VARIABLE_FUNCTION_SYNC_RUNTIME_CACHE 13 +/* + * The payload for this function is + * SMM_VARIABLE_COMMUNICATE_GET_RUNTIME_CACHE_INFO + */ +#define SMM_VARIABLE_FUNCTION_GET_RUNTIME_CACHE_INFO 14 + +/** + * struct smm_variable_communicate_header - Used for SMM variable communication + + * @function: function to call in Smm. + * @ret_status: return status + * @data: payload + */ +struct smm_variable_communicate_header { + size_t function; + efi_status_t ret_status; + u8 data[]; +}; + +#define MM_VARIABLE_COMMUNICATE_SIZE \ + (sizeof(struct smm_variable_communicate_header)) + +/** + * struct smm_variable_access - Used to communicate with StMM by + * SetVariable and GetVariable. + + * @guid: vendor GUID + * @data_size: size of EFI variable data + * @name_size: size of EFI name + * @attr: attributes + * @name: variable name + * + */ +struct smm_variable_access { + efi_guid_t guid; + size_t data_size; + size_t name_size; + u32 attr; + u16 name[]; +}; + +#define MM_VARIABLE_ACCESS_HEADER_SIZE \ + (sizeof(struct smm_variable_access)) +/** + * struct smm_variable_payload_size - Used to get the max allowed + * payload used in StMM. + * + * @size: size to fill in + * + */ +struct smm_variable_payload_size { + size_t size; +}; + +/** + * struct smm_variable_getnext - Used to communicate with StMM for + * GetNextVariableName. + * + * @guid: vendor GUID + * @name_size: size of the name of the variable + * @name: variable name + * + */ +struct smm_variable_getnext { + efi_guid_t guid; + size_t name_size; + u16 name[]; +}; + +#define MM_VARIABLE_GET_NEXT_HEADER_SIZE \ + (sizeof(struct smm_variable_getnext)) + +/** + * struct smm_variable_query_info - Used to communicate with StMM for + * QueryVariableInfo. + * + * @max_variable_storage: max available storage + * @remaining_variable_storage: remaining available storage + * @max_variable_size: max variable supported size + * @attr: attributes to query storage for + * + */ +struct smm_variable_query_info { + u64 max_variable_storage; + u64 remaining_variable_storage; + u64 max_variable_size; + u32 attr; +}; + +#define VAR_CHECK_VARIABLE_PROPERTY_REVISION 0x0001 +#define VAR_CHECK_VARIABLE_PROPERTY_READ_ONLY BIT(0) +/** + * struct var_check_property - Used to store variable properties in StMM + * + * @revision: magic revision number for variable property checking + * @property: properties mask for the variable used in StMM. + * Currently RO flag is supported + * @attributes: variable attributes used in StMM checking when properties + * for a variable are enabled + * @minsize: minimum allowed size for variable payload checked against + * smm_variable_access->datasize in StMM + * @maxsize: maximum allowed size for variable payload checked against + * smm_variable_access->datasize in StMM + * + */ +struct var_check_property { + u16 revision; + u16 property; + u32 attributes; + size_t minsize; + size_t maxsize; +}; + +/** + * struct smm_variable_var_check_property - Used to communicate variable + * properties with StMM + * + * @guid: vendor GUID + * @name_size: size of EFI name + * @property: variable properties struct + * @name: variable name + * + */ +struct smm_variable_var_check_property { + efi_guid_t guid; + size_t name_size; + struct var_check_property property; + u16 name[]; +}; + +#endif /* _MM_COMMUNICATION_H_ */ diff --git a/drivers/firmware/efi/stmm/tee_stmm_efi.c b/drivers/firmware/efi/stmm/tee_stmm_efi.c new file mode 100644 index 000000000000..f741ca279052 --- /dev/null +++ b/drivers/firmware/efi/stmm/tee_stmm_efi.c @@ -0,0 +1,616 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * EFI variable service via TEE + * + * Copyright (C) 2022 Linaro + */ + +#include <linux/efi.h> +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/tee.h> +#include <linux/tee_drv.h> +#include <linux/ucs2_string.h> +#include "mm_communication.h" + +static struct efivars tee_efivars; +static struct efivar_operations tee_efivar_ops; + +static size_t max_buffer_size; /* comm + var + func + data */ +static size_t max_payload_size; /* func + data */ + +struct tee_stmm_efi_private { + struct tee_context *ctx; + u32 session; + struct device *dev; +}; + +static struct tee_stmm_efi_private pvt_data; + +/* UUID of the stmm PTA */ +static const struct tee_client_device_id tee_stmm_efi_id_table[] = { + {PTA_STMM_UUID}, + {} +}; + +static int tee_ctx_match(struct tee_ioctl_version_data *ver, const void *data) +{ + /* currently only OP-TEE is supported as a communication path */ + if (ver->impl_id == TEE_IMPL_ID_OPTEE) + return 1; + else + return 0; +} + +/** + * tee_mm_communicate() - Pass a buffer to StandaloneMM running in TEE + * + * @comm_buf: locally allocated communication buffer + * @dsize: buffer size + * Return: status code + */ +static efi_status_t tee_mm_communicate(void *comm_buf, size_t dsize) +{ + size_t buf_size; + struct efi_mm_communicate_header *mm_hdr; + struct tee_ioctl_invoke_arg arg; + struct tee_param param[4]; + struct tee_shm *shm = NULL; + int rc; + + if (!comm_buf) + return EFI_INVALID_PARAMETER; + + mm_hdr = (struct efi_mm_communicate_header *)comm_buf; + buf_size = mm_hdr->message_len + sizeof(efi_guid_t) + sizeof(size_t); + + if (dsize != buf_size) + return EFI_INVALID_PARAMETER; + + shm = tee_shm_register_kernel_buf(pvt_data.ctx, comm_buf, buf_size); + if (IS_ERR(shm)) { + dev_err(pvt_data.dev, "Unable to register shared memory\n"); + return EFI_UNSUPPORTED; + } + + memset(&arg, 0, sizeof(arg)); + arg.func = PTA_STMM_CMD_COMMUNICATE; + arg.session = pvt_data.session; + arg.num_params = 4; + + memset(param, 0, sizeof(param)); + param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT; + param[0].u.memref.size = buf_size; + param[0].u.memref.shm = shm; + param[1].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT; + param[2].attr = TEE_IOCTL_PARAM_ATTR_TYPE_NONE; + param[3].attr = TEE_IOCTL_PARAM_ATTR_TYPE_NONE; + + rc = tee_client_invoke_func(pvt_data.ctx, &arg, param); + tee_shm_free(shm); + + if (rc < 0 || arg.ret != 0) { + dev_err(pvt_data.dev, + "PTA_STMM_CMD_COMMUNICATE invoke error: 0x%x\n", arg.ret); + return EFI_DEVICE_ERROR; + } + + switch (param[1].u.value.a) { + case ARM_SVC_SPM_RET_SUCCESS: + return EFI_SUCCESS; + + case ARM_SVC_SPM_RET_INVALID_PARAMS: + return EFI_INVALID_PARAMETER; + + case ARM_SVC_SPM_RET_DENIED: + return EFI_ACCESS_DENIED; + + case ARM_SVC_SPM_RET_NO_MEMORY: + return EFI_OUT_OF_RESOURCES; + + default: + return EFI_ACCESS_DENIED; + } +} + +/** + * mm_communicate() - Adjust the communication buffer to StandAlonneMM and send + * it to TEE + * + * @comm_buf: locally allocated communication buffer, buffer should + * be enough big to have some headers and payload + * @payload_size: payload size + * Return: status code + */ +static efi_status_t mm_communicate(u8 *comm_buf, size_t payload_size) +{ + size_t dsize; + efi_status_t ret; + struct efi_mm_communicate_header *mm_hdr; + struct smm_variable_communicate_header *var_hdr; + + dsize = payload_size + MM_COMMUNICATE_HEADER_SIZE + + MM_VARIABLE_COMMUNICATE_SIZE; + mm_hdr = (struct efi_mm_communicate_header *)comm_buf; + var_hdr = (struct smm_variable_communicate_header *)mm_hdr->data; + + ret = tee_mm_communicate(comm_buf, dsize); + if (ret != EFI_SUCCESS) { + dev_err(pvt_data.dev, "%s failed!\n", __func__); + return ret; + } + + return var_hdr->ret_status; +} + +/** + * setup_mm_hdr() - Allocate a buffer for StandAloneMM and initialize the + * header data. + * + * @dptr: pointer address to store allocated buffer + * @payload_size: payload size + * @func: standAloneMM function number + * @ret: EFI return code + * Return: pointer to corresponding StandAloneMM function buffer or NULL + */ +static void *setup_mm_hdr(u8 **dptr, size_t payload_size, size_t func, + efi_status_t *ret) +{ + const efi_guid_t mm_var_guid = EFI_MM_VARIABLE_GUID; + struct efi_mm_communicate_header *mm_hdr; + struct smm_variable_communicate_header *var_hdr; + u8 *comm_buf; + + /* In the init function we initialize max_buffer_size with + * get_max_payload(). So skip the test if max_buffer_size is initialized + * StandAloneMM will perform similar checks and drop the buffer if it's + * too long + */ + if (max_buffer_size && + max_buffer_size < (MM_COMMUNICATE_HEADER_SIZE + + MM_VARIABLE_COMMUNICATE_SIZE + payload_size)) { + *ret = EFI_INVALID_PARAMETER; + return NULL; + } + + comm_buf = kzalloc(MM_COMMUNICATE_HEADER_SIZE + + MM_VARIABLE_COMMUNICATE_SIZE + payload_size, + GFP_KERNEL); + if (!comm_buf) { + *ret = EFI_OUT_OF_RESOURCES; + return NULL; + } + + mm_hdr = (struct efi_mm_communicate_header *)comm_buf; + memcpy(&mm_hdr->header_guid, &mm_var_guid, sizeof(mm_hdr->header_guid)); + mm_hdr->message_len = MM_VARIABLE_COMMUNICATE_SIZE + payload_size; + + var_hdr = (struct smm_variable_communicate_header *)mm_hdr->data; + var_hdr->function = func; + if (dptr) + *dptr = comm_buf; + *ret = EFI_SUCCESS; + + return var_hdr->data; +} + +/** + * get_max_payload() - Get variable payload size from StandAloneMM. + * + * @size: size of the variable in storage + * Return: status code + */ +static efi_status_t get_max_payload(size_t *size) +{ + struct smm_variable_payload_size *var_payload = NULL; + size_t payload_size; + u8 *comm_buf = NULL; + efi_status_t ret; + + if (!size) + return EFI_INVALID_PARAMETER; + + payload_size = sizeof(*var_payload); + var_payload = setup_mm_hdr(&comm_buf, payload_size, + SMM_VARIABLE_FUNCTION_GET_PAYLOAD_SIZE, + &ret); + if (!var_payload) + return EFI_OUT_OF_RESOURCES; + + ret = mm_communicate(comm_buf, payload_size); + if (ret != EFI_SUCCESS) + goto out; + + /* Make sure the buffer is big enough for storing variables */ + if (var_payload->size < MM_VARIABLE_ACCESS_HEADER_SIZE + 0x20) { + ret = EFI_DEVICE_ERROR; + goto out; + } + *size = var_payload->size; + /* + * There seems to be a bug in EDK2 miscalculating the boundaries and + * size checks, so deduct 2 more bytes to fulfill this requirement. Fix + * it up here to ensure backwards compatibility with older versions + * (cf. StandaloneMmPkg/Drivers/StandaloneMmCpu/AArch64/EventHandle.c. + * sizeof (EFI_MM_COMMUNICATE_HEADER) instead the size minus the + * flexible array member). + * + * size is guaranteed to be > 2 due to checks on the beginning. + */ + *size -= 2; +out: + kfree(comm_buf); + return ret; +} + +static efi_status_t get_property_int(u16 *name, size_t name_size, + const efi_guid_t *vendor, + struct var_check_property *var_property) +{ + struct smm_variable_var_check_property *smm_property; + size_t payload_size; + u8 *comm_buf = NULL; + efi_status_t ret; + + memset(var_property, 0, sizeof(*var_property)); + payload_size = sizeof(*smm_property) + name_size; + if (payload_size > max_payload_size) + return EFI_INVALID_PARAMETER; + + smm_property = setup_mm_hdr( + &comm_buf, payload_size, + SMM_VARIABLE_FUNCTION_VAR_CHECK_VARIABLE_PROPERTY_GET, &ret); + if (!smm_property) + return EFI_OUT_OF_RESOURCES; + + memcpy(&smm_property->guid, vendor, sizeof(smm_property->guid)); + smm_property->name_size = name_size; + memcpy(smm_property->name, name, name_size); + + ret = mm_communicate(comm_buf, payload_size); + /* + * Currently only R/O property is supported in StMM. + * Variables that are not set to R/O will not set the property in StMM + * and the call will return EFI_NOT_FOUND. We are setting the + * properties to 0x0 so checking against that is enough for the + * EFI_NOT_FOUND case. + */ + if (ret == EFI_NOT_FOUND) + ret = EFI_SUCCESS; + if (ret != EFI_SUCCESS) + goto out; + memcpy(var_property, &smm_property->property, sizeof(*var_property)); + +out: + kfree(comm_buf); + return ret; +} + +static efi_status_t tee_get_variable(u16 *name, efi_guid_t *vendor, + u32 *attributes, unsigned long *data_size, + void *data) +{ + struct var_check_property var_property; + struct smm_variable_access *var_acc; + size_t payload_size; + size_t name_size; + size_t tmp_dsize; + u8 *comm_buf = NULL; + efi_status_t ret; + + if (!name || !vendor || !data_size) + return EFI_INVALID_PARAMETER; + + name_size = (ucs2_strnlen(name, EFI_VAR_NAME_LEN) + 1) * sizeof(u16); + if (name_size > max_payload_size - MM_VARIABLE_ACCESS_HEADER_SIZE) + return EFI_INVALID_PARAMETER; + + /* Trim output buffer size */ + tmp_dsize = *data_size; + if (name_size + tmp_dsize > + max_payload_size - MM_VARIABLE_ACCESS_HEADER_SIZE) { + tmp_dsize = max_payload_size - MM_VARIABLE_ACCESS_HEADER_SIZE - + name_size; + } + + payload_size = MM_VARIABLE_ACCESS_HEADER_SIZE + name_size + tmp_dsize; + var_acc = setup_mm_hdr(&comm_buf, payload_size, + SMM_VARIABLE_FUNCTION_GET_VARIABLE, &ret); + if (!var_acc) + return EFI_OUT_OF_RESOURCES; + + /* Fill in contents */ + memcpy(&var_acc->guid, vendor, sizeof(var_acc->guid)); + var_acc->data_size = tmp_dsize; + var_acc->name_size = name_size; + var_acc->attr = attributes ? *attributes : 0; + memcpy(var_acc->name, name, name_size); + + ret = mm_communicate(comm_buf, payload_size); + if (ret == EFI_SUCCESS || ret == EFI_BUFFER_TOO_SMALL) + /* Update with reported data size for trimmed case */ + *data_size = var_acc->data_size; + if (ret != EFI_SUCCESS) + goto out; + + ret = get_property_int(name, name_size, vendor, &var_property); + if (ret != EFI_SUCCESS) + goto out; + + if (attributes) + *attributes = var_acc->attr; + + if (!data) { + ret = EFI_INVALID_PARAMETER; + goto out; + } + memcpy(data, (u8 *)var_acc->name + var_acc->name_size, + var_acc->data_size); +out: + kfree(comm_buf); + return ret; +} + +static efi_status_t tee_get_next_variable(unsigned long *name_size, + efi_char16_t *name, efi_guid_t *guid) +{ + struct smm_variable_getnext *var_getnext; + size_t payload_size; + size_t out_name_size; + size_t in_name_size; + u8 *comm_buf = NULL; + efi_status_t ret; + + if (!name_size || !name || !guid) + return EFI_INVALID_PARAMETER; + + out_name_size = *name_size; + in_name_size = (ucs2_strnlen(name, EFI_VAR_NAME_LEN) + 1) * sizeof(u16); + + if (out_name_size < in_name_size) + return EFI_INVALID_PARAMETER; + + if (in_name_size > max_payload_size - MM_VARIABLE_GET_NEXT_HEADER_SIZE) + return EFI_INVALID_PARAMETER; + + /* Trim output buffer size */ + if (out_name_size > max_payload_size - MM_VARIABLE_GET_NEXT_HEADER_SIZE) + out_name_size = + max_payload_size - MM_VARIABLE_GET_NEXT_HEADER_SIZE; + + payload_size = MM_VARIABLE_GET_NEXT_HEADER_SIZE + out_name_size; + var_getnext = setup_mm_hdr(&comm_buf, payload_size, + SMM_VARIABLE_FUNCTION_GET_NEXT_VARIABLE_NAME, + &ret); + if (!var_getnext) + return EFI_OUT_OF_RESOURCES; + + /* Fill in contents */ + memcpy(&var_getnext->guid, guid, sizeof(var_getnext->guid)); + var_getnext->name_size = out_name_size; + memcpy(var_getnext->name, name, in_name_size); + memset((u8 *)var_getnext->name + in_name_size, 0x0, + out_name_size - in_name_size); + + ret = mm_communicate(comm_buf, payload_size); + if (ret == EFI_SUCCESS || ret == EFI_BUFFER_TOO_SMALL) { + /* Update with reported data size for trimmed case */ + *name_size = var_getnext->name_size; + } + if (ret != EFI_SUCCESS) + goto out; + + memcpy(guid, &var_getnext->guid, sizeof(*guid)); + memcpy(name, var_getnext->name, var_getnext->name_size); + +out: + kfree(comm_buf); + return ret; +} + +static efi_status_t tee_set_variable(efi_char16_t *name, efi_guid_t *vendor, + u32 attributes, unsigned long data_size, + void *data) +{ + efi_status_t ret; + struct var_check_property var_property; + struct smm_variable_access *var_acc; + size_t payload_size; + size_t name_size; + u8 *comm_buf = NULL; + + if (!name || name[0] == 0 || !vendor) + return EFI_INVALID_PARAMETER; + + if (data_size > 0 && !data) + return EFI_INVALID_PARAMETER; + + /* Check payload size */ + name_size = (ucs2_strnlen(name, EFI_VAR_NAME_LEN) + 1) * sizeof(u16); + payload_size = MM_VARIABLE_ACCESS_HEADER_SIZE + name_size + data_size; + if (payload_size > max_payload_size) + return EFI_INVALID_PARAMETER; + + /* + * Allocate the buffer early, before switching to RW (if needed) + * so we won't need to account for any failures in reading/setting + * the properties, if the allocation fails + */ + var_acc = setup_mm_hdr(&comm_buf, payload_size, + SMM_VARIABLE_FUNCTION_SET_VARIABLE, &ret); + if (!var_acc) + return EFI_OUT_OF_RESOURCES; + + /* + * The API has the ability to override RO flags. If no RO check was + * requested switch the variable to RW for the duration of this call + */ + ret = get_property_int(name, name_size, vendor, &var_property); + if (ret != EFI_SUCCESS) { + dev_err(pvt_data.dev, "Getting variable property failed\n"); + goto out; + } + + if (var_property.property & VAR_CHECK_VARIABLE_PROPERTY_READ_ONLY) { + ret = EFI_WRITE_PROTECTED; + goto out; + } + + /* Fill in contents */ + memcpy(&var_acc->guid, vendor, sizeof(var_acc->guid)); + var_acc->data_size = data_size; + var_acc->name_size = name_size; + var_acc->attr = attributes; + memcpy(var_acc->name, name, name_size); + memcpy((u8 *)var_acc->name + name_size, data, data_size); + + ret = mm_communicate(comm_buf, payload_size); + dev_dbg(pvt_data.dev, "Set Variable %s %d %lx\n", __FILE__, __LINE__, ret); +out: + kfree(comm_buf); + return ret; +} + +static efi_status_t tee_set_variable_nonblocking(efi_char16_t *name, + efi_guid_t *vendor, + u32 attributes, + unsigned long data_size, + void *data) +{ + return EFI_UNSUPPORTED; +} + +static efi_status_t tee_query_variable_info(u32 attributes, + u64 *max_variable_storage_size, + u64 *remain_variable_storage_size, + u64 *max_variable_size) +{ + struct smm_variable_query_info *mm_query_info; + size_t payload_size; + efi_status_t ret; + u8 *comm_buf; + + payload_size = sizeof(*mm_query_info); + mm_query_info = setup_mm_hdr(&comm_buf, payload_size, + SMM_VARIABLE_FUNCTION_QUERY_VARIABLE_INFO, + &ret); + if (!mm_query_info) + return EFI_OUT_OF_RESOURCES; + + mm_query_info->attr = attributes; + ret = mm_communicate(comm_buf, payload_size); + if (ret != EFI_SUCCESS) + goto out; + *max_variable_storage_size = mm_query_info->max_variable_storage; + *remain_variable_storage_size = + mm_query_info->remaining_variable_storage; + *max_variable_size = mm_query_info->max_variable_size; + +out: + kfree(comm_buf); + return ret; +} + +static void tee_stmm_efi_close_context(void *data) +{ + tee_client_close_context(pvt_data.ctx); +} + +static void tee_stmm_efi_close_session(void *data) +{ + tee_client_close_session(pvt_data.ctx, pvt_data.session); +} + +static void tee_stmm_restore_efivars_generic_ops(void) +{ + efivars_unregister(&tee_efivars); + efivars_generic_ops_register(); +} + +static int tee_stmm_efi_probe(struct device *dev) +{ + struct tee_ioctl_open_session_arg sess_arg; + efi_status_t ret; + int rc; + + pvt_data.ctx = tee_client_open_context(NULL, tee_ctx_match, NULL, NULL); + if (IS_ERR(pvt_data.ctx)) + return -ENODEV; + + rc = devm_add_action_or_reset(dev, tee_stmm_efi_close_context, NULL); + if (rc) + return rc; + + /* Open session with StMM PTA */ + memset(&sess_arg, 0, sizeof(sess_arg)); + export_uuid(sess_arg.uuid, &tee_stmm_efi_id_table[0].uuid); + rc = tee_client_open_session(pvt_data.ctx, &sess_arg, NULL); + if ((rc < 0) || (sess_arg.ret != 0)) { + dev_err(dev, "tee_client_open_session failed, err: %x\n", + sess_arg.ret); + return -EINVAL; + } + pvt_data.session = sess_arg.session; + pvt_data.dev = dev; + rc = devm_add_action_or_reset(dev, tee_stmm_efi_close_session, NULL); + if (rc) + return rc; + + ret = get_max_payload(&max_payload_size); + if (ret != EFI_SUCCESS) + return -EIO; + + max_buffer_size = MM_COMMUNICATE_HEADER_SIZE + + MM_VARIABLE_COMMUNICATE_SIZE + + max_payload_size; + + tee_efivar_ops.get_variable = tee_get_variable; + tee_efivar_ops.get_next_variable = tee_get_next_variable; + tee_efivar_ops.set_variable = tee_set_variable; + tee_efivar_ops.set_variable_nonblocking = tee_set_variable_nonblocking; + tee_efivar_ops.query_variable_store = efi_query_variable_store; + tee_efivar_ops.query_variable_info = tee_query_variable_info; + + efivars_generic_ops_unregister(); + pr_info("Using TEE-based EFI runtime variable services\n"); + efivars_register(&tee_efivars, &tee_efivar_ops); + + return 0; +} + +static int tee_stmm_efi_remove(struct device *dev) +{ + tee_stmm_restore_efivars_generic_ops(); + + return 0; +} + +MODULE_DEVICE_TABLE(tee, tee_stmm_efi_id_table); + +static struct tee_client_driver tee_stmm_efi_driver = { + .id_table = tee_stmm_efi_id_table, + .driver = { + .name = "tee-stmm-efi", + .bus = &tee_bus_type, + .probe = tee_stmm_efi_probe, + .remove = tee_stmm_efi_remove, + }, +}; + +static int __init tee_stmm_efi_mod_init(void) +{ + return driver_register(&tee_stmm_efi_driver.driver); +} + +static void __exit tee_stmm_efi_mod_exit(void) +{ + driver_unregister(&tee_stmm_efi_driver.driver); +} + +module_init(tee_stmm_efi_mod_init); +module_exit(tee_stmm_efi_mod_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Ilias Apalodimas <ilias.apalodimas@linaro.org>"); +MODULE_AUTHOR("Masahisa Kojima <masahisa.kojima@linaro.org>"); +MODULE_DESCRIPTION("TEE based EFI runtime variable service driver"); diff --git a/drivers/firmware/efi/vars.c b/drivers/firmware/efi/vars.c index e9dc7116daf1..f654e6f6af87 100644 --- a/drivers/firmware/efi/vars.c +++ b/drivers/firmware/efi/vars.c @@ -63,6 +63,7 @@ int efivars_register(struct efivars *efivars, const struct efivar_operations *ops) { int rv; + int event; if (down_interruptible(&efivars_lock)) return -EINTR; @@ -77,6 +78,13 @@ int efivars_register(struct efivars *efivars, __efivars = efivars; + if (efivar_supports_writes()) + event = EFIVAR_OPS_RDWR; + else + event = EFIVAR_OPS_RDONLY; + + blocking_notifier_call_chain(&efivar_ops_nh, event, NULL); + pr_info("Registered efivars operations\n"); rv = 0; out: |