From 2608015921f61425f09e3a413f22be6c155a13a7 Mon Sep 17 00:00:00 2001 From: Heinrich Schuchardt Date: Thu, 18 Apr 2024 04:32:02 +0200 Subject: efi_loader: typo mstching %s/mstching/matching/ Reported-by: E Shattow Signed-off-by: Heinrich Schuchardt Reviewed-by: Ilias Apalodimas --- lib/efi_loader/efi_var_common.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'lib/efi_loader') diff --git a/lib/efi_loader/efi_var_common.c b/lib/efi_loader/efi_var_common.c index aa8feffd3ec..ed53bcf3939 100644 --- a/lib/efi_loader/efi_var_common.c +++ b/lib/efi_loader/efi_var_common.c @@ -419,7 +419,7 @@ void *efi_get_var(const u16 *name, const efi_guid_t *vendor, efi_uintn_t *size) } /** - * efi_var_collect() - Copy EFI variables mstching attributes mask + * efi_var_collect() - Copy EFI variables matching attributes mask * * @bufp: buffer containing variable collection * @lenp: buffer length -- cgit v1.2.3 From 05bf7adf87b02feb593fb553e377cd196a4598f0 Mon Sep 17 00:00:00 2001 From: Masahisa Kojima Date: Mon, 4 Dec 2023 13:30:14 +0900 Subject: efi_loader: use event callback for initrd deregistration Currently efi_initrd_deregister() is called in bootefi.c when the image started from bootefi command returns. Since efi_guid_event_group_return_to_efibootmgr event is implemented, so let's use this event for invoking initrd deregistration. Signed-off-by: Masahisa Kojima Reviewed-by: Ilias Apalodimas Tested-by: Ilias Apalodimas Signed-off-by: Heinrich Schuchardt --- lib/efi_loader/efi_helper.c | 5 --- lib/efi_loader/efi_load_initrd.c | 82 +++++++++++++++++++++++++++------------- 2 files changed, 55 insertions(+), 32 deletions(-) (limited to 'lib/efi_loader') diff --git a/lib/efi_loader/efi_helper.c b/lib/efi_loader/efi_helper.c index 58761fae784..6918fd5e48a 100644 --- a/lib/efi_loader/efi_helper.c +++ b/lib/efi_loader/efi_helper.c @@ -549,11 +549,6 @@ efi_status_t do_bootefi_exec(efi_handle_t handle, void *load_options) out: free(load_options); - if (IS_ENABLED(CONFIG_EFI_LOAD_FILE2_INITRD)) { - if (efi_initrd_deregister() != EFI_SUCCESS) - log_err("Failed to remove loadfile2 for initrd\n"); - } - /* Notify EFI_EVENT_GROUP_RETURN_TO_EFIBOOTMGR event group. */ list_for_each_entry(evt, &efi_events, link) { if (evt->group && diff --git a/lib/efi_loader/efi_load_initrd.c b/lib/efi_loader/efi_load_initrd.c index 2b467b55481..67d1f75d525 100644 --- a/lib/efi_loader/efi_load_initrd.c +++ b/lib/efi_loader/efi_load_initrd.c @@ -183,6 +183,50 @@ out: return ret; } +/** + * efi_initrd_deregister() - delete the handle for loading initial RAM disk + * + * This will delete the handle containing the Linux specific vendor device + * path and EFI_LOAD_FILE2_PROTOCOL for loading an initrd + * + * Return: status code + */ +efi_status_t efi_initrd_deregister(void) +{ + efi_status_t ret; + + if (!efi_initrd_handle) + return EFI_SUCCESS; + + ret = efi_uninstall_multiple_protocol_interfaces(efi_initrd_handle, + /* initramfs */ + &efi_guid_device_path, + &dp_lf2_handle, + /* LOAD_FILE2 */ + &efi_guid_load_file2_protocol, + &efi_lf2_protocol, + NULL); + efi_initrd_handle = NULL; + + return ret; +} + +/** + * efi_initrd_return_notify() - return to efibootmgr callback + * + * @event: the event for which this notification function is registered + * @context: event context + */ +static void EFIAPI efi_initrd_return_notify(struct efi_event *event, + void *context) +{ + efi_status_t ret; + + EFI_ENTRY("%p, %p", event, context); + ret = efi_initrd_deregister(); + EFI_EXIT(ret); +} + /** * efi_initrd_register() - create handle for loading initial RAM disk * @@ -196,6 +240,7 @@ out: efi_status_t efi_initrd_register(void) { efi_status_t ret; + struct efi_event *event; /* * Allow the user to continue if Boot#### file path is not set for @@ -214,34 +259,17 @@ efi_status_t efi_initrd_register(void) &efi_guid_load_file2_protocol, &efi_lf2_protocol, NULL); + if (ret != EFI_SUCCESS) { + log_err("installing EFI_LOAD_FILE2_PROTOCOL failed\n"); + return ret; + } - return ret; -} - -/** - * efi_initrd_deregister() - delete the handle for loading initial RAM disk - * - * This will delete the handle containing the Linux specific vendor device - * path and EFI_LOAD_FILE2_PROTOCOL for loading an initrd - * - * Return: status code - */ -efi_status_t efi_initrd_deregister(void) -{ - efi_status_t ret; - - if (!efi_initrd_handle) - return EFI_SUCCESS; - - ret = efi_uninstall_multiple_protocol_interfaces(efi_initrd_handle, - /* initramfs */ - &efi_guid_device_path, - &dp_lf2_handle, - /* LOAD_FILE2 */ - &efi_guid_load_file2_protocol, - &efi_lf2_protocol, - NULL); - efi_initrd_handle = NULL; + ret = efi_create_event(EVT_NOTIFY_SIGNAL, TPL_CALLBACK, + efi_initrd_return_notify, NULL, + &efi_guid_event_group_return_to_efibootmgr, + &event); + if (ret != EFI_SUCCESS) + log_err("Creating event failed\n"); return ret; } -- cgit v1.2.3 From c28d32f946f0d1c0780a02ab49dc2c1835370501 Mon Sep 17 00:00:00 2001 From: Ilias Apalodimas Date: Thu, 18 Apr 2024 15:54:50 +0300 Subject: efi_loader: conditionally enable SetvariableRT When we store EFI variables on file we don't allow SetVariable at runtime, since the OS doesn't know how to access or write that file. At the same time keeping the U-Boot drivers alive in runtime sections and performing writes from the firmware is dangerous -- if at all possible. For GetVariable at runtime we copy runtime variables in RAM and expose them to the OS. Add a Kconfig option and provide SetVariable at runtime using the same memory backend. The OS will be responsible for syncing the RAM contents to the file, otherwise any changes made during runtime won't persist reboots. It's worth noting that the variable store format is defined in EBBR [0] and authenticated variables are explicitly prohibited, since they have to be stored on a medium that's tamper and rollback protected. - pre-patch $~ mount | grep efiva efivarfs on /sys/firmware/efi/efivars type efivarfs (ro,nosuid,nodev,noexec,relatime) $~ efibootmgr -n 0001 Could not set BootNext: Read-only file system - post-patch $~ mount | grep efiva efivarfs on /sys/firmware/efi/efivars type efivarfs (rw,nosuid,nodev,noexec,relatime) $~ efibootmgr -n 0001 BootNext: 0001 BootCurrent: 0000 BootOrder: 0000,0001 Boot0000* debian HD(1,GPT,bdae5610-3331-4e4d-9466-acb5caf0b4a6,0x800,0x100000)/File(EFI\debian\grubaa64.efi) Boot0001* virtio 0 VenHw(e61d73b9-a384-4acc-aeab-82e828f3628b,0000000000000000)/VenHw(e61d73b9-a384-4acc-aeab-82e828f3628b,850000001f000000)/VenHw(e61d73b9-a384-4acc-aeab-82e828f3628b,1600850000000000){auto_created_boot_option} $~ efivar -p -n 8be4df61-93ca-11d2-aa0d-00e098032b8c-BootNext GUID: 8be4df61-93ca-11d2-aa0d-00e098032b8c Name: "BootNext" Attributes: Non-Volatile Boot Service Access Runtime Service Access Value: 00000000 01 00 FWTS runtime results Skipped tests are for SetVariable which is now supported 'Passed' test is for QueryVariableInfo which is not yet supported Test: UEFI miscellaneous runtime service interface tests. Test for UEFI miscellaneous runtime service interfaces 6 skipped Stress test for UEFI miscellaneous runtime service i.. 1 skipped Test GetNextHighMonotonicCount with invalid NULL par.. 1 skipped Test UEFI miscellaneous runtime services unsupported.. 1 passed Test: UEFI Runtime service variable interface tests. Test UEFI RT service get variable interface. 1 passed Test UEFI RT service get next variable name interface. 4 passed Test UEFI RT service set variable interface. 8 passed Test UEFI RT service query variable info interface. 1 skipped Test UEFI RT service variable interface stress test. 2 passed Test UEFI RT service set variable interface stress t.. 4 passed Test UEFI RT service query variable info interface s.. 1 skipped Test UEFI RT service get variable interface, invalid.. 5 passed Test UEFI RT variable services unsupported status. 1 passed, 3 skipped [0] https://arm-software.github.io/ebbr/index.html#document-chapter5-variable-storage Reviewed-by: Heinrich Schuchardt Signed-off-by: Ilias Apalodimas --- lib/efi_loader/Kconfig | 16 ++++++ lib/efi_loader/efi_runtime.c | 4 ++ lib/efi_loader/efi_variable.c | 116 ++++++++++++++++++++++++++++++++++++++---- 3 files changed, 125 insertions(+), 11 deletions(-) (limited to 'lib/efi_loader') diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig index e13a6f9f4c3..cc8371a3bb4 100644 --- a/lib/efi_loader/Kconfig +++ b/lib/efi_loader/Kconfig @@ -62,6 +62,22 @@ config EFI_VARIABLE_FILE_STORE Select this option if you want non-volatile UEFI variables to be stored as file /ubootefi.var on the EFI system partition. +config EFI_RT_VOLATILE_STORE + bool "Allow variable runtime services in volatile storage (e.g RAM)" + depends on EFI_VARIABLE_FILE_STORE + help + When EFI variables are stored on file we don't allow SetVariableRT, + since the OS doesn't know how to write that file. At he same time + we copy runtime variables in DRAM and support GetVariableRT + + Enable this option to allow SetVariableRT on the RAM backend of + the EFI variable storage. The OS will be responsible for syncing + the RAM contents to the file, otherwise any changes made during + runtime won't persist reboots. + Authenticated variables are not supported. Note that this will + violate the EFI spec since writing auth variables will return + EFI_INVALID_PARAMETER + config EFI_MM_COMM_TEE bool "UEFI variables storage service via the trusted world" depends on OPTEE diff --git a/lib/efi_loader/efi_runtime.c b/lib/efi_loader/efi_runtime.c index a61c9a77b13..dde083b0966 100644 --- a/lib/efi_loader/efi_runtime.c +++ b/lib/efi_loader/efi_runtime.c @@ -127,6 +127,10 @@ efi_status_t efi_init_runtime_supported(void) EFI_RT_SUPPORTED_SET_VIRTUAL_ADDRESS_MAP | EFI_RT_SUPPORTED_CONVERT_POINTER; + if (IS_ENABLED(CONFIG_EFI_RT_VOLATILE_STORE)) + rt_table->runtime_services_supported |= + EFI_RT_SUPPORTED_SET_VARIABLE; + /* * This value must be synced with efi_runtime_detach_list * as well as efi_runtime_services. diff --git a/lib/efi_loader/efi_variable.c b/lib/efi_loader/efi_variable.c index e6c1219a11c..47bb7992057 100644 --- a/lib/efi_loader/efi_variable.c +++ b/lib/efi_loader/efi_variable.c @@ -219,17 +219,20 @@ efi_get_next_variable_name_int(efi_uintn_t *variable_name_size, return efi_get_next_variable_name_mem(variable_name_size, variable_name, vendor); } -efi_status_t efi_set_variable_int(const u16 *variable_name, - const efi_guid_t *vendor, - u32 attributes, efi_uintn_t data_size, - const void *data, bool ro_check) +/** + * setvariable_allowed() - checks defined by the UEFI spec for setvariable + * + * @variable_name: name of the variable + * @vendor: vendor GUID + * @attributes: attributes of the variable + * @data_size: size of the buffer with the variable value + * @data: buffer with the variable value + * Return: status code + */ +static efi_status_t __efi_runtime +setvariable_allowed(const u16 *variable_name, const efi_guid_t *vendor, + u32 attributes, efi_uintn_t data_size, const void *data) { - struct efi_var_entry *var; - efi_uintn_t ret; - bool append, delete; - u64 time = 0; - enum efi_auth_var_type var_type; - if (!variable_name || !*variable_name || !vendor) return EFI_INVALID_PARAMETER; @@ -261,6 +264,25 @@ efi_status_t efi_set_variable_int(const u16 *variable_name, !(attributes & EFI_VARIABLE_BOOTSERVICE_ACCESS))) return EFI_INVALID_PARAMETER; + return EFI_SUCCESS; +} + +efi_status_t efi_set_variable_int(const u16 *variable_name, + const efi_guid_t *vendor, + u32 attributes, efi_uintn_t data_size, + const void *data, bool ro_check) +{ + struct efi_var_entry *var; + efi_uintn_t ret; + bool append, delete; + u64 time = 0; + enum efi_auth_var_type var_type; + + ret = setvariable_allowed(variable_name, vendor, attributes, data_size, + data); + if (ret != EFI_SUCCESS) + return ret; + /* check if a variable exists */ var = efi_var_mem_find(vendor, variable_name, NULL); append = !!(attributes & EFI_VARIABLE_APPEND_WRITE); @@ -454,7 +476,79 @@ efi_set_variable_runtime(u16 *variable_name, const efi_guid_t *vendor, u32 attributes, efi_uintn_t data_size, const void *data) { - return EFI_UNSUPPORTED; + struct efi_var_entry *var; + efi_uintn_t ret; + bool append, delete; + u64 time = 0; + + if (!IS_ENABLED(CONFIG_EFI_RT_VOLATILE_STORE)) + return EFI_UNSUPPORTED; + + /* + * Authenticated variables are not supported. The EFI spec + * in ยง32.3.6 requires keys to be stored in non-volatile storage which + * is tamper and delete resistant. + * The rest of the checks are in setvariable_allowed() + */ + if (attributes & EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS) + return EFI_INVALID_PARAMETER; + + ret = setvariable_allowed(variable_name, vendor, attributes, data_size, + data); + if (ret != EFI_SUCCESS) + return ret; + + /* check if a variable exists */ + var = efi_var_mem_find(vendor, variable_name, NULL); + append = !!(attributes & EFI_VARIABLE_APPEND_WRITE); + attributes &= ~EFI_VARIABLE_APPEND_WRITE; + delete = !append && (!data_size || !attributes); + + /* BS only variables are hidden deny writing them */ + if (!delete && !(attributes & EFI_VARIABLE_RUNTIME_ACCESS)) + return EFI_INVALID_PARAMETER; + + if (var) { + if (var->attr & EFI_VARIABLE_READ_ONLY || + !(var->attr & EFI_VARIABLE_NON_VOLATILE)) + return EFI_WRITE_PROTECTED; + + /* attributes won't be changed */ + if (!delete && (((var->attr & ~EFI_VARIABLE_READ_ONLY) != + (attributes & ~EFI_VARIABLE_READ_ONLY)))) + return EFI_INVALID_PARAMETER; + time = var->time; + } else { + if (!(attributes & EFI_VARIABLE_NON_VOLATILE)) + return EFI_INVALID_PARAMETER; + if (append && !data_size) + return EFI_SUCCESS; + if (delete) + return EFI_NOT_FOUND; + } + + if (delete) { + /* EFI_NOT_FOUND has been handled before */ + attributes = var->attr; + ret = EFI_SUCCESS; + } else if (append && var) { + u16 *old_data = (void *)((uintptr_t)var->name + + sizeof(u16) * (u16_strlen(var->name) + 1)); + + ret = efi_var_mem_ins(variable_name, vendor, attributes, + var->length, old_data, data_size, data, + time); + } else { + ret = efi_var_mem_ins(variable_name, vendor, attributes, + data_size, data, 0, NULL, time); + } + + if (ret != EFI_SUCCESS) + return ret; + /* We are always inserting new variables, get rid of the old copy */ + efi_var_mem_del(var); + + return EFI_SUCCESS; } /** -- cgit v1.2.3 From bc3dd2493ef8c3c646aaeb3854a3f83558c50102 Mon Sep 17 00:00:00 2001 From: Ilias Apalodimas Date: Thu, 18 Apr 2024 15:54:51 +0300 Subject: efi_loader: Add OS notifications for SetVariable at runtime Previous patches enable SetVariable at runtime using a volatile storage backend using EFI_RUNTIME_SERVICES_DATA allocared memory. Since there's no recommendation from the spec on how to notify the OS, add a volatile EFI variable that contains the filename relative to the ESP. OS'es can use that file and update it at runtime $~ efivar -p -n b2ac5fc9-92b7-4acd-aeac-11e818c3130c-RTStorageVolatile GUID: b2ac5fc9-92b7-4acd-aeac-11e818c3130c Name: "RTStorageVolatile" Attributes: Boot Service Access Runtime Service Access Value: 00000000 75 62 6f 6f 74 65 66 69 2e 76 61 72 00 |ubootefi.var. | Reviewed-by: Heinrich Schuchardt Signed-off-by: Ilias Apalodimas --- lib/efi_loader/efi_runtime.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-) (limited to 'lib/efi_loader') diff --git a/lib/efi_loader/efi_runtime.c b/lib/efi_loader/efi_runtime.c index dde083b0966..c8f7a88ba8d 100644 --- a/lib/efi_loader/efi_runtime.c +++ b/lib/efi_loader/efi_runtime.c @@ -10,6 +10,7 @@ #include #include #include +#include #include #include #include @@ -110,6 +111,7 @@ static __efi_runtime_data efi_uintn_t efi_descriptor_size; */ efi_status_t efi_init_runtime_supported(void) { + const efi_guid_t efi_guid_efi_rt_var_file = U_BOOT_EFI_RT_VAR_FILE_GUID; efi_status_t ret; struct efi_rt_properties_table *rt_table; @@ -127,9 +129,20 @@ efi_status_t efi_init_runtime_supported(void) EFI_RT_SUPPORTED_SET_VIRTUAL_ADDRESS_MAP | EFI_RT_SUPPORTED_CONVERT_POINTER; - if (IS_ENABLED(CONFIG_EFI_RT_VOLATILE_STORE)) - rt_table->runtime_services_supported |= - EFI_RT_SUPPORTED_SET_VARIABLE; + if (IS_ENABLED(CONFIG_EFI_RT_VOLATILE_STORE)) { + ret = efi_set_variable_int(u"RTStorageVolatile", + &efi_guid_efi_rt_var_file, + EFI_VARIABLE_BOOTSERVICE_ACCESS | + EFI_VARIABLE_RUNTIME_ACCESS | + EFI_VARIABLE_READ_ONLY, + sizeof(EFI_VAR_FILE_NAME), + EFI_VAR_FILE_NAME, false); + if (ret != EFI_SUCCESS) { + log_err("Failed to set RTStorageVolatile\n"); + return ret; + } + rt_table->runtime_services_supported |= EFI_RT_SUPPORTED_SET_VARIABLE; + } /* * This value must be synced with efi_runtime_detach_list -- cgit v1.2.3 From 00da8d65a3baea8c3745367bea99b1d76f8f129c Mon Sep 17 00:00:00 2001 From: Ilias Apalodimas Date: Thu, 18 Apr 2024 15:54:52 +0300 Subject: efi_loader: add an EFI variable with the file contents Previous patches enabled SetVariableRT using a RAM backend. Although EBBR [0] defines a variable format we can teach userspace tools and write the altered variables, it's better if we skip the ABI requirements completely. So let's add a new variable, in its own namespace called "VarToFile" which contains a binary dump of the updated RT, BS and, NV variables and will be updated when GetVariable is called. Some adjustments are needed to do that. Currently we discard BS-only variables in EBS(). We need to preserve those on the RAM backend that exposes the variables. Since BS-only variables can't appear at runtime we need to move the memory masking checks from efi_var_collect() to efi_get_next_variable_name_mem()/ efi_get_variable_mem() and do the filtering at runtime. We also need an efi_var_collect() variant available at runtime, in order to construct the "VarToFile" buffer on the fly. All users and applications (for linux) have to do when updating a variable is dd that variable in the file described by "RTStorageVolatile". Linux efivarfs uses a first 4 bytes of the output to represent attributes in little-endian format. So, storing variables works like this: $~ efibootmgr -n 0001 $~ dd if=/sys/firmware/efi/efivars/VarToFile-b2ac5fc9-92b7-4acd-aeac-11e818c3130c of=/boot/efi/ubootefi.var skip=4 bs=1 [0] https://arm-software.github.io/ebbr/index.html#document-chapter5-variable-storage Suggested-by: Ard Biesheuvel # dumping all variables to a variable Co-developed-by: Heinrich Schuchardt # contributed on efi_var_collect_mem() Signed-off-by: Heinrich Schuchardt Signed-off-by: Ilias Apalodimas --- lib/efi_loader/efi_runtime.c | 25 +++++++ lib/efi_loader/efi_var_common.c | 6 +- lib/efi_loader/efi_var_mem.c | 151 +++++++++++++++++++++++++------------- lib/efi_loader/efi_variable.c | 6 +- lib/efi_loader/efi_variable_tee.c | 5 -- 5 files changed, 131 insertions(+), 62 deletions(-) (limited to 'lib/efi_loader') diff --git a/lib/efi_loader/efi_runtime.c b/lib/efi_loader/efi_runtime.c index c8f7a88ba8d..73831c527e0 100644 --- a/lib/efi_loader/efi_runtime.c +++ b/lib/efi_loader/efi_runtime.c @@ -130,6 +130,8 @@ efi_status_t efi_init_runtime_supported(void) EFI_RT_SUPPORTED_CONVERT_POINTER; if (IS_ENABLED(CONFIG_EFI_RT_VOLATILE_STORE)) { + u8 s = 0; + ret = efi_set_variable_int(u"RTStorageVolatile", &efi_guid_efi_rt_var_file, EFI_VARIABLE_BOOTSERVICE_ACCESS | @@ -141,6 +143,29 @@ efi_status_t efi_init_runtime_supported(void) log_err("Failed to set RTStorageVolatile\n"); return ret; } + /* + * This variable needs to be visible so users can read it, + * but the real contents are going to be filled during + * GetVariable + */ + ret = efi_set_variable_int(u"VarToFile", + &efi_guid_efi_rt_var_file, + EFI_VARIABLE_BOOTSERVICE_ACCESS | + EFI_VARIABLE_RUNTIME_ACCESS | + EFI_VARIABLE_READ_ONLY, + sizeof(s), + &s, false); + if (ret != EFI_SUCCESS) { + log_err("Failed to set VarToFile\n"); + efi_set_variable_int(u"RTStorageVolatile", + &efi_guid_efi_rt_var_file, + EFI_VARIABLE_BOOTSERVICE_ACCESS | + EFI_VARIABLE_RUNTIME_ACCESS | + EFI_VARIABLE_READ_ONLY, + 0, NULL, false); + + return ret; + } rt_table->runtime_services_supported |= EFI_RT_SUPPORTED_SET_VARIABLE; } diff --git a/lib/efi_loader/efi_var_common.c b/lib/efi_loader/efi_var_common.c index ed53bcf3939..961139f005a 100644 --- a/lib/efi_loader/efi_var_common.c +++ b/lib/efi_loader/efi_var_common.c @@ -182,7 +182,8 @@ efi_get_variable_runtime(u16 *variable_name, const efi_guid_t *guid, { efi_status_t ret; - ret = efi_get_variable_mem(variable_name, guid, attributes, data_size, data, NULL); + ret = efi_get_variable_mem(variable_name, guid, attributes, data_size, + data, NULL, EFI_VARIABLE_RUNTIME_ACCESS); /* Remove EFI_VARIABLE_READ_ONLY flag */ if (attributes) @@ -195,7 +196,8 @@ efi_status_t __efi_runtime EFIAPI efi_get_next_variable_name_runtime(efi_uintn_t *variable_name_size, u16 *variable_name, efi_guid_t *guid) { - return efi_get_next_variable_name_mem(variable_name_size, variable_name, guid); + return efi_get_next_variable_name_mem(variable_name_size, variable_name, + guid, EFI_VARIABLE_RUNTIME_ACCESS); } /** diff --git a/lib/efi_loader/efi_var_mem.c b/lib/efi_loader/efi_var_mem.c index 6c21cec5d45..940ab663882 100644 --- a/lib/efi_loader/efi_var_mem.c +++ b/lib/efi_loader/efi_var_mem.c @@ -61,6 +61,23 @@ efi_var_mem_compare(struct efi_var_entry *var, const efi_guid_t *guid, return match; } +/** + * efi_var_entry_len() - Get the entry len including headers & name + * + * @var: pointer to variable start + * + * Return: 8-byte aligned variable entry length + */ + +u32 __efi_runtime efi_var_entry_len(struct efi_var_entry *var) +{ + if (!var) + return 0; + + return ALIGN((sizeof(u16) * (u16_strlen(var->name) + 1)) + + var->length + sizeof(*var), 8); +} + struct efi_var_entry __efi_runtime *efi_var_mem_find(const efi_guid_t *guid, const u16 *name, struct efi_var_entry **next) @@ -184,53 +201,6 @@ u64 __efi_runtime efi_var_mem_free(void) sizeof(struct efi_var_entry); } -/** - * efi_var_mem_bs_del() - delete boot service only variables - */ -static void efi_var_mem_bs_del(void) -{ - struct efi_var_entry *var = efi_var_buf->var; - - for (;;) { - struct efi_var_entry *last; - - last = (struct efi_var_entry *) - ((uintptr_t)efi_var_buf + efi_var_buf->length); - if (var >= last) - break; - if (var->attr & EFI_VARIABLE_RUNTIME_ACCESS) { - u16 *data; - - /* skip variable */ - for (data = var->name; *data; ++data) - ; - ++data; - var = (struct efi_var_entry *) - ALIGN((uintptr_t)data + var->length, 8); - } else { - /* delete variable */ - efi_var_mem_del(var); - } - } -} - -/** - * efi_var_mem_notify_exit_boot_services() - ExitBootService callback - * - * @event: callback event - * @context: callback context - */ -static void EFIAPI -efi_var_mem_notify_exit_boot_services(struct efi_event *event, void *context) -{ - EFI_ENTRY("%p, %p", event, context); - - /* Delete boot service only variables */ - efi_var_mem_bs_del(); - - EFI_EXIT(EFI_SUCCESS); -} - /** * efi_var_mem_notify_exit_boot_services() - SetVirtualMemoryMap callback * @@ -261,11 +231,7 @@ efi_status_t efi_var_mem_init(void) efi_var_buf->magic = EFI_VAR_FILE_MAGIC; efi_var_buf->length = (uintptr_t)efi_var_buf->var - (uintptr_t)efi_var_buf; - /* crc32 for 0 bytes = 0 */ - ret = efi_create_event(EVT_SIGNAL_EXIT_BOOT_SERVICES, TPL_CALLBACK, - efi_var_mem_notify_exit_boot_services, NULL, - NULL, &event); if (ret != EFI_SUCCESS) return ret; ret = efi_create_event(EVT_SIGNAL_VIRTUAL_ADDRESS_CHANGE, TPL_CALLBACK, @@ -276,10 +242,71 @@ efi_status_t efi_var_mem_init(void) return ret; } +/** + * efi_var_collect_mem() - Copy EFI variables matching attributes mask from + * efi_var_buf + * + * @buf: buffer containing variable collection + * @lenp: buffer length + * @mask: mask of matched attributes + * + * Return: Status code + */ +efi_status_t __efi_runtime +efi_var_collect_mem(struct efi_var_file *buf, efi_uintn_t *lenp, u32 mask) +{ + static struct efi_var_file __efi_runtime_data hdr = { + .magic = EFI_VAR_FILE_MAGIC, + }; + struct efi_var_entry *last, *var, *var_to; + + hdr.length = sizeof(struct efi_var_file); + + var = efi_var_buf->var; + last = (struct efi_var_entry *) + ((uintptr_t)efi_var_buf + efi_var_buf->length); + if (buf) + var_to = buf->var; + + while (var < last) { + u32 len = efi_var_entry_len(var); + + if ((var->attr & mask) != mask) { + var = (void *)((uintptr_t)var + len); + continue; + } + + hdr.length += len; + + if (buf && hdr.length <= *lenp) { + efi_memcpy_runtime(var_to, var, len); + var_to = (void *)var_to + len; + } + var = (void *)var + len; + } + + if (!buf && hdr.length <= *lenp) { + *lenp = hdr.length; + return EFI_INVALID_PARAMETER; + } + + if (!buf || hdr.length > *lenp) { + *lenp = hdr.length; + return EFI_BUFFER_TOO_SMALL; + } + hdr.crc32 = crc32(0, (u8 *)buf->var, + hdr.length - sizeof(struct efi_var_file)); + + efi_memcpy_runtime(buf, &hdr, sizeof(hdr)); + *lenp = hdr.length; + + return EFI_SUCCESS; +} + efi_status_t __efi_runtime efi_get_variable_mem(const u16 *variable_name, const efi_guid_t *vendor, u32 *attributes, efi_uintn_t *data_size, void *data, - u64 *timep) + u64 *timep, u32 mask) { efi_uintn_t old_size; struct efi_var_entry *var; @@ -291,11 +318,22 @@ efi_get_variable_mem(const u16 *variable_name, const efi_guid_t *vendor, if (!var) return EFI_NOT_FOUND; + /* + * This function is used at runtime to dump EFI variables. + * The memory backend we keep around has BS-only variables as + * well. At runtime we filter them here + */ + if (mask && !((var->attr & mask) == mask)) + return EFI_NOT_FOUND; + if (attributes) *attributes = var->attr; if (timep) *timep = var->time; + if (!u16_strcmp(variable_name, u"VarToFile")) + return efi_var_collect_mem(data, data_size, EFI_VARIABLE_NON_VOLATILE); + old_size = *data_size; *data_size = var->length; if (old_size < var->length) @@ -315,7 +353,8 @@ efi_get_variable_mem(const u16 *variable_name, const efi_guid_t *vendor, efi_status_t __efi_runtime efi_get_next_variable_name_mem(efi_uintn_t *variable_name_size, - u16 *variable_name, efi_guid_t *vendor) + u16 *variable_name, efi_guid_t *vendor, + u32 mask) { struct efi_var_entry *var; efi_uintn_t len, old_size; @@ -324,6 +363,7 @@ efi_get_next_variable_name_mem(efi_uintn_t *variable_name_size, if (!variable_name_size || !variable_name || !vendor) return EFI_INVALID_PARAMETER; +skip: len = *variable_name_size >> 1; if (u16_strnlen(variable_name, len) == len) return EFI_INVALID_PARAMETER; @@ -347,6 +387,11 @@ efi_get_next_variable_name_mem(efi_uintn_t *variable_name_size, efi_memcpy_runtime(variable_name, var->name, *variable_name_size); efi_memcpy_runtime(vendor, &var->guid, sizeof(efi_guid_t)); + if (mask && !((var->attr & mask) == mask)) { + *variable_name_size = old_size; + goto skip; + } + return EFI_SUCCESS; } diff --git a/lib/efi_loader/efi_variable.c b/lib/efi_loader/efi_variable.c index 47bb7992057..0cbed53d1db 100644 --- a/lib/efi_loader/efi_variable.c +++ b/lib/efi_loader/efi_variable.c @@ -209,14 +209,16 @@ efi_get_variable_int(const u16 *variable_name, const efi_guid_t *vendor, u32 *attributes, efi_uintn_t *data_size, void *data, u64 *timep) { - return efi_get_variable_mem(variable_name, vendor, attributes, data_size, data, timep); + return efi_get_variable_mem(variable_name, vendor, attributes, data_size, + data, timep, 0); } efi_status_t __efi_runtime efi_get_next_variable_name_int(efi_uintn_t *variable_name_size, u16 *variable_name, efi_guid_t *vendor) { - return efi_get_next_variable_name_mem(variable_name_size, variable_name, vendor); + return efi_get_next_variable_name_mem(variable_name_size, variable_name, + vendor, 0); } /** diff --git a/lib/efi_loader/efi_variable_tee.c b/lib/efi_loader/efi_variable_tee.c index dde135fd9f8..4f1aa298da1 100644 --- a/lib/efi_loader/efi_variable_tee.c +++ b/lib/efi_loader/efi_variable_tee.c @@ -959,11 +959,6 @@ void efi_variables_boot_exit_notify(void) log_err("Unable to notify the MM partition for ExitBootServices\n"); free(comm_buf); - /* - * Populate the list for runtime variables. - * asking EFI_VARIABLE_RUNTIME_ACCESS is redundant, since - * efi_var_mem_notify_exit_boot_services will clean those, but that's fine - */ ret = efi_var_collect(&var_buf, &len, EFI_VARIABLE_RUNTIME_ACCESS); if (ret != EFI_SUCCESS) log_err("Can't populate EFI variables. No runtime variables will be available\n"); -- cgit v1.2.3