* [PATCH v2 0/4] Enable SetVariable at runtime
@ 2024-04-17 10:19 Ilias Apalodimas
2024-04-17 10:19 ` [PATCH v2 1/4] efi_loader: conditionally enable SetvariableRT Ilias Apalodimas
` (3 more replies)
0 siblings, 4 replies; 12+ messages in thread
From: Ilias Apalodimas @ 2024-04-17 10:19 UTC (permalink / raw)
To: xypron.glpk, kettenis
Cc: caleb.connolly, sumit.garg, quic_llindhol, ardb, pbrobinson,
pjones, Ilias Apalodimas, Tom Rini, Masahisa Kojima,
AKASHI Takahiro, Raymond Mao, Matthias Schiffer, Janne Grunau,
Simon Glass, Abdellatif El Khlifi, Sughosh Ganu,
Richard Henderson, Sam Edwards, Alper Nebi Yasak, Weizhao Ouyang,
u-boot
Hi all,
This is the new version of [0]
The main difference from v1 is that VarToFile is now filled on the fly,
during a GetVariable call for it, instead of creating it during
SetVariable.
The advantage of doing that is memory efficiency, since the buffer comes
from the OS now and we don't have to allocate and preserve runtime memory
to copy things around. We also don't consume space from the existsing
variable storage.
The disadvantage is that it complicates the code a bit more since we need
to check for the variable name in GetVariable. We also need a function to
collect variables at runtime that operates on the memory backend.
In the future we can clean up and try to unify efi_var_collectXXX() variants,
but I'd rather keep tha patchset simpler for now.
We will also need support for QueryVariableInfo, which I will send in
another series as part of a cleanup since it's mostly supported already.
Changes since v1:
- Instead of Creating VarToFile at SetVariable, create it on GetVariable.
This allows us to get rid of the preallocated RT buffer, since the
address is user provided
- convert Set/GetVariableRT -> Set/GetVariable at runtime
- return EFI_INVALID_PARAM is NV is not set at runtime
- Heinrich sent me the efi_var_collect_mem() variant
Changes since the RFC:
- Return EFI_INVALID_PARAM if attributes are not volatile
- Add EFI_WRITE_PROTECTED checks for BS, RT *only* variables
- Add 2 EFI variables and allow userspace to write the file
- Add selftests
[0] https://lore.kernel.org/u-boot/20240406140203.248211-1-ilias.apalodimas@linaro.org/
Ilias Apalodimas (4):
efi_loader: conditionally enable SetvariableRT
efi_loader: Add OS notifications for SetVariable at runtime
efi_loader: add an EFI variable with the file contents
efi_selftest: add tests for setvariableRT
include/efi_loader.h | 4 +
include/efi_variable.h | 14 +-
lib/charset.c | 2 +-
lib/efi_loader/Kconfig | 16 ++
lib/efi_loader/efi_runtime.c | 36 +++++
lib/efi_loader/efi_var_common.c | 6 +-
lib/efi_loader/efi_var_mem.c | 146 +++++++++++-------
lib/efi_loader/efi_variable.c | 121 +++++++++++++--
lib/efi_loader/efi_variable_tee.c | 5 -
.../efi_selftest_variables_runtime.c | 116 +++++++++++++-
10 files changed, 384 insertions(+), 82 deletions(-)
--
2.40.1
^ permalink raw reply [flat|nested] 12+ messages in thread
* [PATCH v2 1/4] efi_loader: conditionally enable SetvariableRT
2024-04-17 10:19 [PATCH v2 0/4] Enable SetVariable at runtime Ilias Apalodimas
@ 2024-04-17 10:19 ` Ilias Apalodimas
2024-04-17 12:27 ` Heinrich Schuchardt
2024-04-17 10:19 ` [PATCH v2 2/4] efi_loader: Add OS notifications for SetVariable at runtime Ilias Apalodimas
` (2 subsequent siblings)
3 siblings, 1 reply; 12+ messages in thread
From: Ilias Apalodimas @ 2024-04-17 10:19 UTC (permalink / raw)
To: xypron.glpk, kettenis
Cc: caleb.connolly, sumit.garg, quic_llindhol, ardb, pbrobinson,
pjones, Ilias Apalodimas, Tom Rini, Masahisa Kojima,
AKASHI Takahiro, Raymond Mao, Janne Grunau, Simon Glass,
Matthias Schiffer, Abdellatif El Khlifi, Sughosh Ganu,
Sam Edwards, Richard Henderson, Alper Nebi Yasak, Weizhao Ouyang,
u-boot
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
[0] https://arm-software.github.io/ebbr/index.html#document-chapter5-variable-storage
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
---
lib/efi_loader/Kconfig | 16 +++
lib/efi_loader/efi_runtime.c | 4 +
lib/efi_loader/efi_variable.c | 115 ++++++++++++++++--
.../efi_selftest_variables_runtime.c | 13 +-
4 files changed, 134 insertions(+), 14 deletions(-)
diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig
index e13a6f9f4c3a..cc8371a3bb4c 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 a61c9a77b13f..dde083b09665 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 e6c1219a11c8..abc2a3402f42 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 +476,78 @@ 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 §32.3.6 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;
+ /* BS only variables are hidden deny writing them */
+ if (!(attributes & EFI_VARIABLE_RUNTIME_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);
+
+ 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;
}
/**
diff --git a/lib/efi_selftest/efi_selftest_variables_runtime.c b/lib/efi_selftest/efi_selftest_variables_runtime.c
index 4700d9424105..4c9405c0a7c7 100644
--- a/lib/efi_selftest/efi_selftest_variables_runtime.c
+++ b/lib/efi_selftest/efi_selftest_variables_runtime.c
@@ -62,9 +62,16 @@ 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)) {
+ 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,
--
2.40.1
^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH v2 2/4] efi_loader: Add OS notifications for SetVariable at runtime
2024-04-17 10:19 [PATCH v2 0/4] Enable SetVariable at runtime Ilias Apalodimas
2024-04-17 10:19 ` [PATCH v2 1/4] efi_loader: conditionally enable SetvariableRT Ilias Apalodimas
@ 2024-04-17 10:19 ` Ilias Apalodimas
2024-04-17 12:35 ` Heinrich Schuchardt
2024-04-17 10:19 ` [PATCH v2 3/4] efi_loader: add an EFI variable with the file contents Ilias Apalodimas
2024-04-17 10:19 ` [PATCH v2 4/4] efi_selftest: add tests for setvariableRT Ilias Apalodimas
3 siblings, 1 reply; 12+ messages in thread
From: Ilias Apalodimas @ 2024-04-17 10:19 UTC (permalink / raw)
To: xypron.glpk, kettenis
Cc: caleb.connolly, sumit.garg, quic_llindhol, ardb, pbrobinson,
pjones, Ilias Apalodimas, Tom Rini, Masahisa Kojima,
AKASHI Takahiro, Raymond Mao, Simon Glass, Janne Grunau,
Matthias Schiffer, Abdellatif El Khlifi, Alper Nebi Yasak,
Sughosh Ganu, Richard Henderson, Sam Edwards, Weizhao Ouyang,
u-boot
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. |
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
---
include/efi_loader.h | 4 ++++
lib/efi_loader/efi_runtime.c | 19 ++++++++++++++++---
2 files changed, 20 insertions(+), 3 deletions(-)
diff --git a/include/efi_loader.h b/include/efi_loader.h
index bb51c0281774..69442f4e58de 100644
--- a/include/efi_loader.h
+++ b/include/efi_loader.h
@@ -159,6 +159,10 @@ static inline void efi_set_bootdev(const char *dev, const char *devnr,
#define EFICONFIG_AUTO_GENERATED_ENTRY_GUID \
EFI_GUID(0x8108ac4e, 0x9f11, 0x4d59, \
0x85, 0x0e, 0xe2, 0x1a, 0x52, 0x2c, 0x59, 0xb2)
+#define U_BOOT_EFI_RT_VAR_FILE_GUID \
+ EFI_GUID(0xb2ac5fc9, 0x92b7, 0x4acd, \
+ 0xae, 0xac, 0x11, 0xe8, 0x18, 0xc3, 0x13, 0x0c)
+
/* Use internal device tree when starting UEFI application */
#define EFI_FDT_USE_INTERNAL NULL
diff --git a/lib/efi_loader/efi_runtime.c b/lib/efi_loader/efi_runtime.c
index dde083b09665..c8f7a88ba8db 100644
--- a/lib/efi_loader/efi_runtime.c
+++ b/lib/efi_loader/efi_runtime.c
@@ -10,6 +10,7 @@
#include <dm.h>
#include <elf.h>
#include <efi_loader.h>
+#include <efi_variable.h>
#include <log.h>
#include <malloc.h>
#include <rtc.h>
@@ -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
--
2.40.1
^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH v2 3/4] efi_loader: add an EFI variable with the file contents
2024-04-17 10:19 [PATCH v2 0/4] Enable SetVariable at runtime Ilias Apalodimas
2024-04-17 10:19 ` [PATCH v2 1/4] efi_loader: conditionally enable SetvariableRT Ilias Apalodimas
2024-04-17 10:19 ` [PATCH v2 2/4] efi_loader: Add OS notifications for SetVariable at runtime Ilias Apalodimas
@ 2024-04-17 10:19 ` Ilias Apalodimas
2024-04-17 13:04 ` Heinrich Schuchardt
2024-04-17 10:19 ` [PATCH v2 4/4] efi_selftest: add tests for setvariableRT Ilias Apalodimas
3 siblings, 1 reply; 12+ messages in thread
From: Ilias Apalodimas @ 2024-04-17 10:19 UTC (permalink / raw)
To: xypron.glpk, kettenis
Cc: caleb.connolly, sumit.garg, quic_llindhol, ardb, pbrobinson,
pjones, Ilias Apalodimas, Heinrich Schuchardt, Tom Rini,
Masahisa Kojima, AKASHI Takahiro, Raymond Mao, Matthias Schiffer,
Simon Glass, Janne Grunau, Abdellatif El Khlifi, Sughosh Ganu,
Richard Henderson, Sam Edwards, Alper Nebi Yasak, Weizhao Ouyang,
u-boot
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
Co-developed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
---
include/efi_variable.h | 14 ++-
lib/charset.c | 2 +-
lib/efi_loader/efi_runtime.c | 19 ++++
lib/efi_loader/efi_var_common.c | 6 +-
lib/efi_loader/efi_var_mem.c | 146 ++++++++++++++++++------------
lib/efi_loader/efi_variable.c | 6 +-
lib/efi_loader/efi_variable_tee.c | 5 -
7 files changed, 130 insertions(+), 68 deletions(-)
diff --git a/include/efi_variable.h b/include/efi_variable.h
index 42a2b7c52bef..b545a36aac50 100644
--- a/include/efi_variable.h
+++ b/include/efi_variable.h
@@ -271,13 +271,16 @@ const efi_guid_t *efi_auth_var_get_guid(const u16 *name);
*
* @variable_name_size: size of variable_name buffer in bytes
* @variable_name: name of uefi variable's name in u16
+ * @mask: bitmask with required attributes of variables to be collected.
+ * variables are only collected if all of the required
+ * attributes match. Use 0 to skip matching
* @vendor: vendor's guid
*
* Return: status code
*/
efi_status_t __efi_runtime
efi_get_next_variable_name_mem(efi_uintn_t *variable_name_size, u16 *variable_name,
- efi_guid_t *vendor);
+ efi_guid_t *vendor, u32 mask);
/**
* efi_get_variable_mem() - Runtime common code across efi variable
* implementations for GetVariable() from
@@ -289,12 +292,15 @@ efi_get_next_variable_name_mem(efi_uintn_t *variable_name_size, u16 *variable_na
* @data_size: size of the buffer to which the variable value is copied
* @data: buffer to which the variable value is copied
* @timep: authentication time (seconds since start of epoch)
+ * @mask: bitmask with required attributes of variables to be collected.
+ * variables are only collected if all of the required
+ * attributes match. Use 0 to skip matching
* Return: status code
*/
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_get_variable_runtime() - runtime implementation of GetVariable()
@@ -334,4 +340,8 @@ efi_get_next_variable_name_runtime(efi_uintn_t *variable_name_size,
*/
void efi_var_buf_update(struct efi_var_file *var_buf);
+efi_status_t __efi_runtime efi_var_collect_mem(struct efi_var_file *buf,
+ efi_uintn_t *lenp,
+ u32 check_attr_mask);
+
#endif
diff --git a/lib/charset.c b/lib/charset.c
index df4f04074852..182c92a50c48 100644
--- a/lib/charset.c
+++ b/lib/charset.c
@@ -387,7 +387,7 @@ int u16_strcasecmp(const u16 *s1, const u16 *s2)
* > 0 if the first different u16 in s1 is greater than the
* corresponding u16 in s2
*/
-int u16_strncmp(const u16 *s1, const u16 *s2, size_t n)
+int __efi_runtime u16_strncmp(const u16 *s1, const u16 *s2, size_t n)
{
int ret = 0;
diff --git a/lib/efi_loader/efi_runtime.c b/lib/efi_loader/efi_runtime.c
index c8f7a88ba8db..99ad1f35d8f1 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)) {
+ int s = 0;
+
ret = efi_set_variable_int(u"RTStorageVolatile",
&efi_guid_efi_rt_var_file,
EFI_VARIABLE_BOOTSERVICE_ACCESS |
@@ -141,6 +143,23 @@ efi_status_t efi_init_runtime_supported(void)
log_err("Failed to set RTStorageVolatile\n");
return ret;
}
+ ret = efi_set_variable_int(u"VarToFile",
+ &efi_guid_efi_rt_var_file,
+ EFI_VARIABLE_BOOTSERVICE_ACCESS |
+ EFI_VARIABLE_RUNTIME_ACCESS,
+ 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 aa8feffd3ec1..7862f2d6ce8a 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 6c21cec5d457..65ab858c926e 100644
--- a/lib/efi_loader/efi_var_mem.c
+++ b/lib/efi_loader/efi_var_mem.c
@@ -36,9 +36,11 @@ efi_var_mem_compare(struct efi_var_entry *var, const efi_guid_t *guid,
const u16 *data, *var_name;
bool match = true;
- for (guid1 = (u8 *)&var->guid, guid2 = (u8 *)guid, i = 0;
- i < sizeof(efi_guid_t) && match; ++i)
- match = (guid1[i] == guid2[i]);
+ if (guid) {
+ for (guid1 = (u8 *)&var->guid, guid2 = (u8 *)guid, i = 0;
+ i < sizeof(efi_guid_t) && match; ++i)
+ match = (guid1[i] == guid2[i]);
+ }
for (data = var->name, var_name = name;; ++data) {
if (match)
@@ -184,53 +186,6 @@ 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 +216,7 @@ 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 +227,75 @@ 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;
+ struct efi_var_entry *var_next;
+
+ efi_var_mem_compare(var, NULL, u"", &var_next);
+ len = (uintptr_t)var_next - (uintptr_t)var;
+
+ if ((var->attr & mask) != mask) {
+ var = (void *)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 +307,22 @@ 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 +342,8 @@ 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 +352,7 @@ 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 +376,11 @@ 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 abc2a3402f42..4aaa05a617d7 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 dde135fd9f81..4f1aa298da13 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");
--
2.40.1
^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH v2 4/4] efi_selftest: add tests for setvariableRT
2024-04-17 10:19 [PATCH v2 0/4] Enable SetVariable at runtime Ilias Apalodimas
` (2 preceding siblings ...)
2024-04-17 10:19 ` [PATCH v2 3/4] efi_loader: add an EFI variable with the file contents Ilias Apalodimas
@ 2024-04-17 10:19 ` Ilias Apalodimas
2024-04-17 12:22 ` Heinrich Schuchardt
3 siblings, 1 reply; 12+ messages in thread
From: Ilias Apalodimas @ 2024-04-17 10:19 UTC (permalink / raw)
To: xypron.glpk, kettenis
Cc: caleb.connolly, sumit.garg, quic_llindhol, ardb, pbrobinson,
pjones, Ilias Apalodimas, Tom Rini, Masahisa Kojima,
AKASHI Takahiro, Raymond Mao, Matthias Schiffer, Janne Grunau,
Simon Glass, Abdellatif El Khlifi, Alper Nebi Yasak,
Sughosh Ganu, Sam Edwards, Richard Henderson, Weizhao Ouyang,
u-boot
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
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
---
.../efi_selftest_variables_runtime.c | 103 ++++++++++++++++++
1 file changed, 103 insertions(+)
diff --git a/lib/efi_selftest/efi_selftest_variables_runtime.c b/lib/efi_selftest/efi_selftest_variables_runtime.c
index 4c9405c0a7c7..e492b50a43c2 100644
--- a/lib/efi_selftest/efi_selftest_variables_runtime.c
+++ b/lib/efi_selftest/efi_selftest_variables_runtime.c
@@ -10,6 +10,7 @@
*/
#include <efi_selftest.h>
+#include <efi_variable.h>
#define EFI_ST_MAX_DATA_SIZE 16
#define EFI_ST_MAX_VARNAME_SIZE 40
@@ -17,6 +18,8 @@
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.
@@ -45,11 +48,14 @@ static int execute(void)
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);
@@ -63,10 +69,107 @@ 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;
+
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;
+ }
+
+ 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 will 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;
+ }
+
+ /* SetVariableRT updates VarToFile with 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,
+ sizeof(v), v);
+ if (ret != EFI_SUCCESS) {
+ efi_st_error("SetVariable failed\n");
+ return EFI_ST_FAILURE;
+ }
+ len = sizeof(data2);
+ delta = 2 * (u16_strlen(u"efi_st_var0") + 1) + sizeof(v) +
+ sizeof(struct efi_var_entry);
+ 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 will updateVarToFile */
+ 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,
+ sizeof(v), v);
+ if (ret != EFI_SUCCESS) {
+ efi_st_error("SetVariable failed\n");
+ return EFI_ST_FAILURE;
+ }
+ prev_len = len;
+ delta = sizeof(v);
+ 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;
+ }
+
+ /* 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");
--
2.40.1
^ permalink raw reply related [flat|nested] 12+ messages in thread
* Re: [PATCH v2 4/4] efi_selftest: add tests for setvariableRT
2024-04-17 10:19 ` [PATCH v2 4/4] efi_selftest: add tests for setvariableRT Ilias Apalodimas
@ 2024-04-17 12:22 ` Heinrich Schuchardt
2024-04-17 12:33 ` Ilias Apalodimas
0 siblings, 1 reply; 12+ messages in thread
From: Heinrich Schuchardt @ 2024-04-17 12:22 UTC (permalink / raw)
To: Ilias Apalodimas
Cc: caleb.connolly, sumit.garg, quic_llindhol, ardb, pbrobinson,
pjones, Tom Rini, Masahisa Kojima, AKASHI Takahiro, Raymond Mao,
Matthias Schiffer, Janne Grunau, Simon Glass,
Abdellatif El Khlifi, Alper Nebi Yasak, Sughosh Ganu,
Sam Edwards, Richard Henderson, Weizhao Ouyang, u-boot, kettenis
On 17.04.24 12:19, Ilias Apalodimas wrote:
> 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
>
> Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
> ---
> .../efi_selftest_variables_runtime.c | 103 ++++++++++++++++++
> 1 file changed, 103 insertions(+)
>
> diff --git a/lib/efi_selftest/efi_selftest_variables_runtime.c b/lib/efi_selftest/efi_selftest_variables_runtime.c
> index 4c9405c0a7c7..e492b50a43c2 100644
> --- a/lib/efi_selftest/efi_selftest_variables_runtime.c
> +++ b/lib/efi_selftest/efi_selftest_variables_runtime.c
> @@ -10,6 +10,7 @@
> */
>
> #include <efi_selftest.h>
> +#include <efi_variable.h>
>
> #define EFI_ST_MAX_DATA_SIZE 16
> #define EFI_ST_MAX_VARNAME_SIZE 40
> @@ -17,6 +18,8 @@
> 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.
> @@ -45,11 +48,14 @@ static int execute(void)
> 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);
> @@ -63,10 +69,107 @@ 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;
> +
> 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;
> + }
> +
> + 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 will 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;
> + }
> +
> + /* SetVariableRT updates VarToFile with 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,
> + sizeof(v), v);
It is fine to test with variable name size (24) and variable value size
(16) both being multiples of 8. But this does not cover the generic case.
> + if (ret != EFI_SUCCESS) {
> + efi_st_error("SetVariable failed\n");
> + return EFI_ST_FAILURE;
> + }
> + len = sizeof(data2);
> + delta = 2 * (u16_strlen(u"efi_st_var0") + 1) + sizeof(v) +
> + sizeof(struct efi_var_entry);
In the file all variable are stored at 8 byte aligned positions.
I am missing ALIGN(,8) here.
> + 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;
> + }
We should check the header fields of VarToFile (reserved, magic, length,
crc32), e.g.
struct efi_var_file *hdr = (void *)data2;
if (memcmp(hdr->magic, EFI_VAR_FILE_MAGIC, 8) ||
len != ALIGN(hdr->length + sizeof(hdr), 8) ||
... )
> +
> + /* append on an existing variable will updateVarToFile */
> + 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,
> + sizeof(v), v);
How about just appending 1 byte when using EFI_VARIABLE_APPEND_WRITE and
checking that the delta here too?
Best regards
Heinrich
> + if (ret != EFI_SUCCESS) {
> + efi_st_error("SetVariable failed\n");
> + return EFI_ST_FAILURE;
> + }
> + prev_len = len;
> + delta = sizeof(v);
> + 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;
> + }
> +
> + /* 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");
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v2 1/4] efi_loader: conditionally enable SetvariableRT
2024-04-17 10:19 ` [PATCH v2 1/4] efi_loader: conditionally enable SetvariableRT Ilias Apalodimas
@ 2024-04-17 12:27 ` Heinrich Schuchardt
2024-04-17 12:33 ` Ilias Apalodimas
0 siblings, 1 reply; 12+ messages in thread
From: Heinrich Schuchardt @ 2024-04-17 12:27 UTC (permalink / raw)
To: Ilias Apalodimas, kettenis
Cc: caleb.connolly, sumit.garg, quic_llindhol, ardb, pbrobinson,
pjones, Tom Rini, Masahisa Kojima, AKASHI Takahiro, Raymond Mao,
Janne Grunau, Simon Glass, Matthias Schiffer,
Abdellatif El Khlifi, Sughosh Ganu, Sam Edwards,
Richard Henderson, Alper Nebi Yasak, Weizhao Ouyang, u-boot,
Heinrich Schuchardt
On 17.04.24 12:19, Ilias Apalodimas wrote:
> 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
>
> [0] https://arm-software.github.io/ebbr/index.html#document-chapter5-variable-storage
>
> Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
> ---
> lib/efi_loader/Kconfig | 16 +++
> lib/efi_loader/efi_runtime.c | 4 +
> lib/efi_loader/efi_variable.c | 115 ++++++++++++++++--
> .../efi_selftest_variables_runtime.c | 13 +-
> 4 files changed, 134 insertions(+), 14 deletions(-)
>
> diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig
> index e13a6f9f4c3a..cc8371a3bb4c 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 a61c9a77b13f..dde083b09665 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 e6c1219a11c8..abc2a3402f42 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 +476,78 @@ 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 §32.3.6 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;
> + /* BS only variables are hidden deny writing them */
> + if (!(attributes & EFI_VARIABLE_RUNTIME_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);
> +
> + 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;
> }
>
> /**
> diff --git a/lib/efi_selftest/efi_selftest_variables_runtime.c b/lib/efi_selftest/efi_selftest_variables_runtime.c
> index 4700d9424105..4c9405c0a7c7 100644
> --- a/lib/efi_selftest/efi_selftest_variables_runtime.c
> +++ b/lib/efi_selftest/efi_selftest_variables_runtime.c
> @@ -62,9 +62,16 @@ 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)) {
> + if (ret != EFI_INVALID_PARAMETER) {
A comment might be helpful here:
/* At runtime only non-volatile variables may be set. */
Otherwise looks good to me.
Reviewed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
> + 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,
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v2 4/4] efi_selftest: add tests for setvariableRT
2024-04-17 12:22 ` Heinrich Schuchardt
@ 2024-04-17 12:33 ` Ilias Apalodimas
0 siblings, 0 replies; 12+ messages in thread
From: Ilias Apalodimas @ 2024-04-17 12:33 UTC (permalink / raw)
To: Heinrich Schuchardt
Cc: caleb.connolly, sumit.garg, quic_llindhol, ardb, pbrobinson,
pjones, Tom Rini, Masahisa Kojima, AKASHI Takahiro, Raymond Mao,
Matthias Schiffer, Janne Grunau, Simon Glass,
Abdellatif El Khlifi, Alper Nebi Yasak, Sughosh Ganu,
Sam Edwards, Richard Henderson, Weizhao Ouyang, u-boot, kettenis
Hi Heinrich,
[...]
> >
> > + memset(v2, 0x1, sizeof(v2));
> > ret = runtime->query_variable_info(EFI_VARIABLE_BOOTSERVICE_ACCESS,
> > &max_storage, &rem_storage,
> > &max_size);
> > @@ -63,10 +69,107 @@ 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;
> > +
> > 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;
> > + }
> > +
> > + 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 will 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;
> > + }
> > +
> > + /* SetVariableRT updates VarToFile with 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,
> > + sizeof(v), v);
>
> It is fine to test with variable name size (24) and variable value size
> (16) both being multiples of 8. But this does not cover the generic case.
We already test SetVariable with a non-aligned variable at the start.
I'll keep this as is and add append 1byte at the last test as you suggested.
>
> > + if (ret != EFI_SUCCESS) {
> > + efi_st_error("SetVariable failed\n");
> > + return EFI_ST_FAILURE;
> > + }
> > + len = sizeof(data2);
> > + delta = 2 * (u16_strlen(u"efi_st_var0") + 1) + sizeof(v) +
> > + sizeof(struct efi_var_entry);
>
> In the file all variable are stored at 8 byte aligned positions.
> I am missing ALIGN(,8) here.
Ah yes
>
> > + 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;
> > + }
>
> We should check the header fields of VarToFile (reserved, magic, length,
> crc32), e.g.
>
> struct efi_var_file *hdr = (void *)data2;
> if (memcmp(hdr->magic, EFI_VAR_FILE_MAGIC, 8) ||
> len != ALIGN(hdr->length + sizeof(hdr), 8) ||
> ... )
Sure, good idea,
>
> > +
> > + /* append on an existing variable will updateVarToFile */
> > + 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,
> > + sizeof(v), v);
>
> How about just appending 1 byte when using EFI_VARIABLE_APPEND_WRITE and
> checking that the delta here too?
Yes, I'll change this
[...]
Thanks
/Ilias
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v2 1/4] efi_loader: conditionally enable SetvariableRT
2024-04-17 12:27 ` Heinrich Schuchardt
@ 2024-04-17 12:33 ` Ilias Apalodimas
0 siblings, 0 replies; 12+ messages in thread
From: Ilias Apalodimas @ 2024-04-17 12:33 UTC (permalink / raw)
To: Heinrich Schuchardt
Cc: kettenis, caleb.connolly, sumit.garg, quic_llindhol, ardb,
pbrobinson, pjones, Tom Rini, Masahisa Kojima, AKASHI Takahiro,
Raymond Mao, Janne Grunau, Simon Glass, Matthias Schiffer,
Abdellatif El Khlifi, Sughosh Ganu, Sam Edwards,
Richard Henderson, Alper Nebi Yasak, Weizhao Ouyang, u-boot,
Heinrich Schuchardt
On Wed, 17 Apr 2024 at 15:28, Heinrich Schuchardt
<heinrich.schuchardt@canonical.com> wrote:
>
> On 17.04.24 12:19, Ilias Apalodimas wrote:
> > 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
> >
> > [0] https://arm-software.github.io/ebbr/index.html#document-chapter5-variable-storage
> >
> > Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
> > ---
> > lib/efi_loader/Kconfig | 16 +++
> > lib/efi_loader/efi_runtime.c | 4 +
> > lib/efi_loader/efi_variable.c | 115 ++++++++++++++++--
> > .../efi_selftest_variables_runtime.c | 13 +-
> > 4 files changed, 134 insertions(+), 14 deletions(-)
> >
> > diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig
> > index e13a6f9f4c3a..cc8371a3bb4c 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 a61c9a77b13f..dde083b09665 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 e6c1219a11c8..abc2a3402f42 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 +476,78 @@ 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 §32.3.6 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;
> > + /* BS only variables are hidden deny writing them */
> > + if (!(attributes & EFI_VARIABLE_RUNTIME_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);
> > +
> > + 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;
> > }
> >
> > /**
> > diff --git a/lib/efi_selftest/efi_selftest_variables_runtime.c b/lib/efi_selftest/efi_selftest_variables_runtime.c
> > index 4700d9424105..4c9405c0a7c7 100644
> > --- a/lib/efi_selftest/efi_selftest_variables_runtime.c
> > +++ b/lib/efi_selftest/efi_selftest_variables_runtime.c
> > @@ -62,9 +62,16 @@ 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)) {
> > + if (ret != EFI_INVALID_PARAMETER) {
>
> A comment might be helpful here:
>
> /* At runtime only non-volatile variables may be set. */
>
> Otherwise looks good to me.
>
> Reviewed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Thanks, Heinrich!
I'll add the comment in v3
>
> > + 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,
>
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v2 2/4] efi_loader: Add OS notifications for SetVariable at runtime
2024-04-17 10:19 ` [PATCH v2 2/4] efi_loader: Add OS notifications for SetVariable at runtime Ilias Apalodimas
@ 2024-04-17 12:35 ` Heinrich Schuchardt
0 siblings, 0 replies; 12+ messages in thread
From: Heinrich Schuchardt @ 2024-04-17 12:35 UTC (permalink / raw)
To: Ilias Apalodimas
Cc: caleb.connolly, sumit.garg, quic_llindhol, ardb, pbrobinson,
pjones, Tom Rini, Masahisa Kojima, AKASHI Takahiro, Raymond Mao,
Simon Glass, Janne Grunau, Matthias Schiffer,
Abdellatif El Khlifi, Alper Nebi Yasak, Sughosh Ganu,
Richard Henderson, Sam Edwards, Weizhao Ouyang, u-boot, kettenis,
Heinrich Schuchardt
On 17.04.24 12:19, Ilias Apalodimas wrote:
> 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. |
>
> Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Reviewed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
> ---
> include/efi_loader.h | 4 ++++
> lib/efi_loader/efi_runtime.c | 19 ++++++++++++++++---
> 2 files changed, 20 insertions(+), 3 deletions(-)
>
> diff --git a/include/efi_loader.h b/include/efi_loader.h
> index bb51c0281774..69442f4e58de 100644
> --- a/include/efi_loader.h
> +++ b/include/efi_loader.h
> @@ -159,6 +159,10 @@ static inline void efi_set_bootdev(const char *dev, const char *devnr,
> #define EFICONFIG_AUTO_GENERATED_ENTRY_GUID \
> EFI_GUID(0x8108ac4e, 0x9f11, 0x4d59, \
> 0x85, 0x0e, 0xe2, 0x1a, 0x52, 0x2c, 0x59, 0xb2)
> +#define U_BOOT_EFI_RT_VAR_FILE_GUID \
> + EFI_GUID(0xb2ac5fc9, 0x92b7, 0x4acd, \
> + 0xae, 0xac, 0x11, 0xe8, 0x18, 0xc3, 0x13, 0x0c)
> +
>
> /* Use internal device tree when starting UEFI application */
> #define EFI_FDT_USE_INTERNAL NULL
> diff --git a/lib/efi_loader/efi_runtime.c b/lib/efi_loader/efi_runtime.c
> index dde083b09665..c8f7a88ba8db 100644
> --- a/lib/efi_loader/efi_runtime.c
> +++ b/lib/efi_loader/efi_runtime.c
> @@ -10,6 +10,7 @@
> #include <dm.h>
> #include <elf.h>
> #include <efi_loader.h>
> +#include <efi_variable.h>
> #include <log.h>
> #include <malloc.h>
> #include <rtc.h>
> @@ -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
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v2 3/4] efi_loader: add an EFI variable with the file contents
2024-04-17 10:19 ` [PATCH v2 3/4] efi_loader: add an EFI variable with the file contents Ilias Apalodimas
@ 2024-04-17 13:04 ` Heinrich Schuchardt
2024-04-17 13:20 ` Ilias Apalodimas
0 siblings, 1 reply; 12+ messages in thread
From: Heinrich Schuchardt @ 2024-04-17 13:04 UTC (permalink / raw)
To: Ilias Apalodimas
Cc: caleb.connolly, sumit.garg, quic_llindhol, ardb, pbrobinson,
pjones, Heinrich Schuchardt, Tom Rini, Masahisa Kojima,
AKASHI Takahiro, Raymond Mao, Matthias Schiffer, Simon Glass,
Janne Grunau, Abdellatif El Khlifi, Sughosh Ganu,
Richard Henderson, Sam Edwards, Alper Nebi Yasak, Weizhao Ouyang,
u-boot, kettenis, Heinrich Schuchardt
On 17.04.24 12:19, Ilias Apalodimas wrote:
> 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
>
> Co-developed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
> Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
> Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
> ---
> include/efi_variable.h | 14 ++-
> lib/charset.c | 2 +-
> lib/efi_loader/efi_runtime.c | 19 ++++
> lib/efi_loader/efi_var_common.c | 6 +-
> lib/efi_loader/efi_var_mem.c | 146 ++++++++++++++++++------------
> lib/efi_loader/efi_variable.c | 6 +-
> lib/efi_loader/efi_variable_tee.c | 5 -
> 7 files changed, 130 insertions(+), 68 deletions(-)
>
> diff --git a/include/efi_variable.h b/include/efi_variable.h
> index 42a2b7c52bef..b545a36aac50 100644
> --- a/include/efi_variable.h
> +++ b/include/efi_variable.h
> @@ -271,13 +271,16 @@ const efi_guid_t *efi_auth_var_get_guid(const u16 *name);
> *
> * @variable_name_size: size of variable_name buffer in bytes
> * @variable_name: name of uefi variable's name in u16
> + * @mask: bitmask with required attributes of variables to be collected.
> + * variables are only collected if all of the required
> + * attributes match. Use 0 to skip matching
> * @vendor: vendor's guid
> *
> * Return: status code
> */
> efi_status_t __efi_runtime
> efi_get_next_variable_name_mem(efi_uintn_t *variable_name_size, u16 *variable_name,
> - efi_guid_t *vendor);
> + efi_guid_t *vendor, u32 mask);
> /**
> * efi_get_variable_mem() - Runtime common code across efi variable
> * implementations for GetVariable() from
> @@ -289,12 +292,15 @@ efi_get_next_variable_name_mem(efi_uintn_t *variable_name_size, u16 *variable_na
> * @data_size: size of the buffer to which the variable value is copied
> * @data: buffer to which the variable value is copied
> * @timep: authentication time (seconds since start of epoch)
> + * @mask: bitmask with required attributes of variables to be collected.
> + * variables are only collected if all of the required
> + * attributes match. Use 0 to skip matching
> * Return: status code
> */
> 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_get_variable_runtime() - runtime implementation of GetVariable()
> @@ -334,4 +340,8 @@ efi_get_next_variable_name_runtime(efi_uintn_t *variable_name_size,
> */
> void efi_var_buf_update(struct efi_var_file *var_buf);
>
> +efi_status_t __efi_runtime efi_var_collect_mem(struct efi_var_file *buf,
> + efi_uintn_t *lenp,
> + u32 check_attr_mask);
> +
> #endif
> diff --git a/lib/charset.c b/lib/charset.c
> index df4f04074852..182c92a50c48 100644
> --- a/lib/charset.c
> +++ b/lib/charset.c
> @@ -387,7 +387,7 @@ int u16_strcasecmp(const u16 *s1, const u16 *s2)
> * > 0 if the first different u16 in s1 is greater than the
> * corresponding u16 in s2
> */
> -int u16_strncmp(const u16 *s1, const u16 *s2, size_t n)
> +int __efi_runtime u16_strncmp(const u16 *s1, const u16 *s2, size_t n)
> {
> int ret = 0;
>
> diff --git a/lib/efi_loader/efi_runtime.c b/lib/efi_loader/efi_runtime.c
> index c8f7a88ba8db..99ad1f35d8f1 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)) {
> + int s = 0;
u8 s = 0;
should be enough.
> +
> ret = efi_set_variable_int(u"RTStorageVolatile",
> &efi_guid_efi_rt_var_file,
> EFI_VARIABLE_BOOTSERVICE_ACCESS |
> @@ -141,6 +143,23 @@ efi_status_t efi_init_runtime_supported(void)
> log_err("Failed to set RTStorageVolatile\n");
> return ret;
> }
> + ret = efi_set_variable_int(u"VarToFile",
> + &efi_guid_efi_rt_var_file,
> + EFI_VARIABLE_BOOTSERVICE_ACCESS |
> + EFI_VARIABLE_RUNTIME_ACCESS,
Why is the variable set here? A comment would be helpful.
If you set it for protection, shouldn't it be EFI_VARIABLE_READ_ONLY?
An alternative would be to return EFI_INVALID_PARAMETER in
efi_set_variable_int for any attempt to set a variable with GUID
efi_guid_efi_rt_var_file.
> + 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 aa8feffd3ec1..7862f2d6ce8a 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 6c21cec5d457..65ab858c926e 100644
> --- a/lib/efi_loader/efi_var_mem.c
> +++ b/lib/efi_loader/efi_var_mem.c
> @@ -36,9 +36,11 @@ efi_var_mem_compare(struct efi_var_entry *var, const efi_guid_t *guid,
> const u16 *data, *var_name;
> bool match = true;
>
> - for (guid1 = (u8 *)&var->guid, guid2 = (u8 *)guid, i = 0;
> - i < sizeof(efi_guid_t) && match; ++i)
> - match = (guid1[i] == guid2[i]);
> + if (guid) {
> + for (guid1 = (u8 *)&var->guid, guid2 = (u8 *)guid, i = 0;
> + i < sizeof(efi_guid_t) && match; ++i)
> + match = (guid1[i] == guid2[i]);
> + }
>
> for (data = var->name, var_name = name;; ++data) {
> if (match)
> @@ -184,53 +186,6 @@ 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 +216,7 @@ 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 +227,75 @@ 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;
> + struct efi_var_entry *var_next;
> +
> + efi_var_mem_compare(var, NULL, u"", &var_next);
On IRC you suggested to make u16_strlen __efi_runtime_code to replace
this efi_var_mem_compare() call and avoid the modifications of said
function. That might be more readable.
Best regards
Heinrich
> + len = (uintptr_t)var_next - (uintptr_t)var;
> +
> + if ((var->attr & mask) != mask) {
> + var = (void *)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 +307,22 @@ 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 +342,8 @@ 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 +352,7 @@ 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 +376,11 @@ 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 abc2a3402f42..4aaa05a617d7 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 dde135fd9f81..4f1aa298da13 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");
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v2 3/4] efi_loader: add an EFI variable with the file contents
2024-04-17 13:04 ` Heinrich Schuchardt
@ 2024-04-17 13:20 ` Ilias Apalodimas
0 siblings, 0 replies; 12+ messages in thread
From: Ilias Apalodimas @ 2024-04-17 13:20 UTC (permalink / raw)
To: Heinrich Schuchardt
Cc: caleb.connolly, sumit.garg, quic_llindhol, ardb, pbrobinson,
pjones, Tom Rini, Masahisa Kojima, AKASHI Takahiro, Raymond Mao,
Matthias Schiffer, Simon Glass, Janne Grunau,
Abdellatif El Khlifi, Sughosh Ganu, Richard Henderson,
Sam Edwards, Alper Nebi Yasak, Weizhao Ouyang, u-boot, kettenis,
Heinrich Schuchardt
Hi Heinrich,
[...]
> > {
> > int ret = 0;
> >
> > diff --git a/lib/efi_loader/efi_runtime.c b/lib/efi_loader/efi_runtime.c
> > index c8f7a88ba8db..99ad1f35d8f1 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)) {
> > + int s = 0;
>
> u8 s = 0;
> should be enough.
Sure,
> > }
> > + ret = efi_set_variable_int(u"VarToFile",
> > + &efi_guid_efi_rt_var_file,
> > + EFI_VARIABLE_BOOTSERVICE_ACCESS |
> > + EFI_VARIABLE_RUNTIME_ACCESS,
>
> Why is the variable set here? A comment would be helpful.
We need to set it so it shows up in the efivarfs, fo linux, and the
variable list in general for other OSes. Otherwise, people won't be
able to read it, unless they specifically search for it. I'll add a
comment though
> If you set it for protection, shouldn't it be EFI_VARIABLE_READ_ONLY?
>
> An alternative would be to return EFI_INVALID_PARAMETER in
> efi_set_variable_int for any attempt to set a variable with GUID
> efi_guid_efi_rt_var_file.
It's not volatile, so it will be treated as RO at runtime. But I'll
add EFI_VARIABLE_READ_ONLY as well. I prefer using the existing EFI
APIs instead of treating GUIDs specially
[...]
> > +/**
> > + * 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;
> > + struct efi_var_entry *var_next;
> > +
> > + efi_var_mem_compare(var, NULL, u"", &var_next);
>
> On IRC you suggested to make u16_strlen __efi_runtime_code to replace
> this efi_var_mem_compare() call and avoid the modifications of said
> function. That might be more readable.
Yes it will, I'll change that on v3. That function will also help us
clean various open-coded sequences of length calculations.
FWIW I just managed to run FWTS over this -- and I also fixed
QueryVariableInfo at runtime
We had 22 tests passing and 1 failing. I am still trying to figure out
what failed, but I'll fix that as well for v3
>
> Best regards
>
> Heinrich
>
> > + len = (uintptr_t)var_next - (uintptr_t)var;
> > +
> > + if ((var->attr & mask) != mask) {
[...]
Thanks
/Ilias
^ permalink raw reply [flat|nested] 12+ messages in thread
end of thread, other threads:[~2024-04-17 13:21 UTC | newest]
Thread overview: 12+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2024-04-17 10:19 [PATCH v2 0/4] Enable SetVariable at runtime Ilias Apalodimas
2024-04-17 10:19 ` [PATCH v2 1/4] efi_loader: conditionally enable SetvariableRT Ilias Apalodimas
2024-04-17 12:27 ` Heinrich Schuchardt
2024-04-17 12:33 ` Ilias Apalodimas
2024-04-17 10:19 ` [PATCH v2 2/4] efi_loader: Add OS notifications for SetVariable at runtime Ilias Apalodimas
2024-04-17 12:35 ` Heinrich Schuchardt
2024-04-17 10:19 ` [PATCH v2 3/4] efi_loader: add an EFI variable with the file contents Ilias Apalodimas
2024-04-17 13:04 ` Heinrich Schuchardt
2024-04-17 13:20 ` Ilias Apalodimas
2024-04-17 10:19 ` [PATCH v2 4/4] efi_selftest: add tests for setvariableRT Ilias Apalodimas
2024-04-17 12:22 ` Heinrich Schuchardt
2024-04-17 12:33 ` Ilias Apalodimas
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.