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_selftest/efi_selftest_variables_runtime.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) (limited to 'lib/efi_selftest/efi_selftest_variables_runtime.c') diff --git a/lib/efi_selftest/efi_selftest_variables_runtime.c b/lib/efi_selftest/efi_selftest_variables_runtime.c index 4700d942410..986924b881d 100644 --- a/lib/efi_selftest/efi_selftest_variables_runtime.c +++ b/lib/efi_selftest/efi_selftest_variables_runtime.c @@ -62,9 +62,17 @@ static int execute(void) EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS, 3, v + 4); - if (ret != EFI_UNSUPPORTED) { - efi_st_error("SetVariable failed\n"); - return EFI_ST_FAILURE; + if (IS_ENABLED(CONFIG_EFI_RT_VOLATILE_STORE)) { + /* At runtime only non-volatile variables may be set. */ + if (ret != EFI_INVALID_PARAMETER) { + efi_st_error("SetVariable failed\n"); + return EFI_ST_FAILURE; + } + } else { + if (ret != EFI_UNSUPPORTED) { + efi_st_error("SetVariable failed\n"); + return EFI_ST_FAILURE; + } } len = EFI_ST_MAX_DATA_SIZE; ret = runtime->get_variable(u"PlatformLangCodes", &guid_vendor0, -- cgit v1.2.3 From 85177b2cf4e9e92eb8454430ed64ecad69df9f92 Mon Sep 17 00:00:00 2001 From: Ilias Apalodimas Date: Thu, 18 Apr 2024 15:54:53 +0300 Subject: efi_selftest: add tests for setvariableRT Since we support SetVariableRT now add the relevant tests - Search for the RTStorageVolatile and VarToFile variables after EBS - Try to update with invalid variales (BS, RT only) - Try to write a variable bigger than our backend storage - Write a variable that fits and check VarToFile has been updated correclty - Append to the variable and check VarToFile changes - Try to delete VarToFile which is write protected - Try to add/delete runtime variables - Verify VarToFile contains a valid file format Signed-off-by: Ilias Apalodimas Reviewed-by: Heinrich Schuchardt --- lib/efi_selftest/efi_selftest_variables_runtime.c | 208 +++++++++++++++++++++- 1 file changed, 207 insertions(+), 1 deletion(-) (limited to 'lib/efi_selftest/efi_selftest_variables_runtime.c') diff --git a/lib/efi_selftest/efi_selftest_variables_runtime.c b/lib/efi_selftest/efi_selftest_variables_runtime.c index 986924b881d..afa91be62c8 100644 --- a/lib/efi_selftest/efi_selftest_variables_runtime.c +++ b/lib/efi_selftest/efi_selftest_variables_runtime.c @@ -10,6 +10,8 @@ */ #include +#include +#include #define EFI_ST_MAX_DATA_SIZE 16 #define EFI_ST_MAX_VARNAME_SIZE 40 @@ -17,6 +19,8 @@ static struct efi_boot_services *boottime; static struct efi_runtime_services *runtime; static const efi_guid_t guid_vendor0 = EFI_GLOBAL_VARIABLE_GUID; +static const efi_guid_t __efi_runtime_data efi_rt_var_guid = + U_BOOT_EFI_RT_VAR_FILE_GUID; /* * Setup unit test. @@ -41,15 +45,18 @@ static int setup(const efi_handle_t img_handle, static int execute(void) { efi_status_t ret; - efi_uintn_t len; + efi_uintn_t len, avail, append_len = 17; u32 attr; u8 v[16] = {0x5d, 0xd1, 0x5e, 0x51, 0x5a, 0x05, 0xc7, 0x0c, 0x35, 0x4a, 0xae, 0x87, 0xa5, 0xdf, 0x0f, 0x65,}; + u8 v2[CONFIG_EFI_VAR_BUF_SIZE]; u8 data[EFI_ST_MAX_DATA_SIZE]; + u8 data2[CONFIG_EFI_VAR_BUF_SIZE]; u16 varname[EFI_ST_MAX_VARNAME_SIZE]; efi_guid_t guid; u64 max_storage, rem_storage, max_size; + memset(v2, 0x1, sizeof(v2)); ret = runtime->query_variable_info(EFI_VARIABLE_BOOTSERVICE_ACCESS, &max_storage, &rem_storage, &max_size); @@ -63,11 +70,210 @@ static int execute(void) EFI_VARIABLE_RUNTIME_ACCESS, 3, v + 4); if (IS_ENABLED(CONFIG_EFI_RT_VOLATILE_STORE)) { + efi_uintn_t prev_len, delta; + struct efi_var_entry *var; + struct efi_var_file *hdr; + /* At runtime only non-volatile variables may be set. */ if (ret != EFI_INVALID_PARAMETER) { efi_st_error("SetVariable failed\n"); return EFI_ST_FAILURE; } + + /* runtime atttribute must be set */ + ret = runtime->set_variable(u"efi_st_var0", &guid_vendor0, + EFI_VARIABLE_BOOTSERVICE_ACCESS | + EFI_VARIABLE_NON_VOLATILE, + 3, v + 4); + if (ret != EFI_INVALID_PARAMETER) { + efi_st_error("SetVariable failed\n"); + return EFI_ST_FAILURE; + } + + len = sizeof(data); + ret = runtime->get_variable(u"RTStorageVolatile", + &efi_rt_var_guid, + &attr, &len, data); + if (ret != EFI_SUCCESS) { + efi_st_error("GetVariable failed\n"); + return EFI_ST_FAILURE; + } + + if (len != sizeof(EFI_VAR_FILE_NAME) || + memcmp(data, EFI_VAR_FILE_NAME, sizeof(EFI_VAR_FILE_NAME))) { + data[len - 1] = 0; + efi_st_error("RTStorageVolatile = %s\n", data); + return EFI_ST_FAILURE; + } + + len = sizeof(data2); + ret = runtime->get_variable(u"VarToFile", &efi_rt_var_guid, + &attr, &len, data2); + if (ret != EFI_SUCCESS) { + efi_st_error("GetVariable failed\n"); + return EFI_ST_FAILURE; + } + /* + * VarToFile size must change once a variable is inserted + * Store it now, we'll use it later + */ + prev_len = len; + ret = runtime->set_variable(u"efi_st_var0", &guid_vendor0, + EFI_VARIABLE_BOOTSERVICE_ACCESS | + EFI_VARIABLE_RUNTIME_ACCESS | + EFI_VARIABLE_NON_VOLATILE, + sizeof(v2), + v2); + /* + * This will try to update VarToFile as well and must fail, + * without changing or deleting VarToFile + */ + if (ret != EFI_OUT_OF_RESOURCES) { + efi_st_error("SetVariable failed\n"); + return EFI_ST_FAILURE; + } + len = sizeof(data2); + ret = runtime->get_variable(u"VarToFile", &efi_rt_var_guid, + &attr, &len, data2); + if (ret != EFI_SUCCESS || prev_len != len) { + efi_st_error("Get/SetVariable failed\n"); + return EFI_ST_FAILURE; + } + + /* Add an 8byte aligned variable */ + ret = runtime->set_variable(u"efi_st_var0", &guid_vendor0, + EFI_VARIABLE_BOOTSERVICE_ACCESS | + EFI_VARIABLE_RUNTIME_ACCESS | + EFI_VARIABLE_NON_VOLATILE, + sizeof(v), v); + if (ret != EFI_SUCCESS) { + efi_st_error("SetVariable failed\n"); + return EFI_ST_FAILURE; + } + + /* Delete it by setting the attrs to 0 */ + ret = runtime->set_variable(u"efi_st_var0", &guid_vendor0, + 0, sizeof(v), v); + if (ret != EFI_SUCCESS) { + efi_st_error("SetVariable failed\n"); + return EFI_ST_FAILURE; + } + + /* Add it back */ + ret = runtime->set_variable(u"efi_st_var0", &guid_vendor0, + EFI_VARIABLE_BOOTSERVICE_ACCESS | + EFI_VARIABLE_RUNTIME_ACCESS | + EFI_VARIABLE_NON_VOLATILE, + sizeof(v), v); + if (ret != EFI_SUCCESS) { + efi_st_error("SetVariable failed\n"); + return EFI_ST_FAILURE; + } + + /* Delete it again by setting the size to 0 */ + ret = runtime->set_variable(u"efi_st_var0", &guid_vendor0, + EFI_VARIABLE_BOOTSERVICE_ACCESS | + EFI_VARIABLE_RUNTIME_ACCESS | + EFI_VARIABLE_NON_VOLATILE, + 0, NULL); + if (ret != EFI_SUCCESS) { + efi_st_error("SetVariable failed\n"); + return EFI_ST_FAILURE; + } + + /* Delete it again and make sure it's not there */ + ret = runtime->set_variable(u"efi_st_var0", &guid_vendor0, + EFI_VARIABLE_BOOTSERVICE_ACCESS | + EFI_VARIABLE_RUNTIME_ACCESS | + EFI_VARIABLE_NON_VOLATILE, + 0, NULL); + if (ret != EFI_NOT_FOUND) { + efi_st_error("SetVariable failed\n"); + return EFI_ST_FAILURE; + } + + /* + * Add a non-aligned variable + * VarToFile updates must include efi_st_var0 + */ + ret = runtime->set_variable(u"efi_st_var0", &guid_vendor0, + EFI_VARIABLE_BOOTSERVICE_ACCESS | + EFI_VARIABLE_RUNTIME_ACCESS | + EFI_VARIABLE_NON_VOLATILE, + 9, v + 4); + if (ret != EFI_SUCCESS) { + efi_st_error("SetVariable failed\n"); + return EFI_ST_FAILURE; + } + var = efi_var_mem_find(&guid_vendor0, u"efi_st_var0", NULL); + if (!var) { + efi_st_error("GetVariable failed\n"); + return EFI_ST_FAILURE; + } + delta = efi_var_entry_len(var); + len = sizeof(data2); + ret = runtime->get_variable(u"VarToFile", &efi_rt_var_guid, + &attr, &len, data2); + if (ret != EFI_SUCCESS || prev_len + delta != len) { + efi_st_error("Get/SetVariable failed\n"); + return EFI_ST_FAILURE; + } + + /* + * Append on an existing variable must update VarToFile + * Our variable entries are 8-byte aligned. + * Adding a single byte will fit on the existing space + */ + prev_len = len; + avail = efi_var_entry_len(var) - + (sizeof(u16) * (u16_strlen(var->name) + 1) + sizeof(*var)) - + var->length; + if (avail >= append_len) + delta = 0; + else + delta = ALIGN(append_len - avail, 8); + ret = runtime->set_variable(u"efi_st_var0", &guid_vendor0, + EFI_VARIABLE_BOOTSERVICE_ACCESS | + EFI_VARIABLE_RUNTIME_ACCESS | + EFI_VARIABLE_APPEND_WRITE | + EFI_VARIABLE_NON_VOLATILE, + append_len, v2); + if (ret != EFI_SUCCESS) { + efi_st_error("SetVariable failed\n"); + return EFI_ST_FAILURE; + } + len = sizeof(data2); + ret = runtime->get_variable(u"VarToFile", &efi_rt_var_guid, + &attr, &len, data2); + if (ret != EFI_SUCCESS) { + efi_st_error("GetVariable failed\n"); + return EFI_ST_FAILURE; + } + if (prev_len + delta != len) { + efi_st_error("Unexpected VarToFile size"); + return EFI_ST_FAILURE; + } + + /* Make sure that variable contains a valid file */ + hdr = (struct efi_var_file *)data2; + if (hdr->magic != EFI_VAR_FILE_MAGIC || + len != hdr->length || + hdr->crc32 != crc32(0, (u8 *)((uintptr_t)data2 + sizeof(struct efi_var_file)), + len - sizeof(struct efi_var_file))) { + efi_st_error("VarToFile invalid header\n"); + return EFI_ST_FAILURE; + } + + /* Variables that are BS, RT and volatile are RO after EBS */ + ret = runtime->set_variable(u"VarToFile", &efi_rt_var_guid, + EFI_VARIABLE_BOOTSERVICE_ACCESS | + EFI_VARIABLE_RUNTIME_ACCESS | + EFI_VARIABLE_NON_VOLATILE, + sizeof(v), v); + if (ret != EFI_WRITE_PROTECTED) { + efi_st_error("Get/SetVariable failed\n"); + return EFI_ST_FAILURE; + } } else { if (ret != EFI_UNSUPPORTED) { efi_st_error("SetVariable failed\n"); -- cgit v1.2.3