Re: [PATCH v2] efi_loader: set CapsuleMax from CONFIG_EFI_CAPSULE_MAX

On Thu, 16 Feb 2023 at 18:21, Etienne Carriere etienne.carriere@linaro.org wrote:

Adds CONFIG_EFI_CAPSULE_MAX to configure the max index value used in EFI capsule reports. The config default value is 65535 as the index max

I forgot to update the commit message. I'll fix in v3.

value used before this change. Platforms with limited storage capacity can set a lower configuration value to prevent storage capacity overflow or even waste of storage space.

Signed-off-by: Etienne Carriere etienne.carriere@linaro.org

Changes since v1

• Changed CONFIG_EFI_CAPSULE_MAX default value from 65535 to 15.

---

lib/efi_loader/Kconfig | 8 ++++++ lib/efi_loader/efi_capsule.c | 48 +++++++++++++++++++++++++----------- lib/efi_loader/efi_setup.c | 7 +++++- 3 files changed, 48 insertions(+), 15 deletions(-)

diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig index c56904afc2..727241dc9c 100644 --- a/lib/efi_loader/Kconfig +++ b/lib/efi_loader/Kconfig @@ -226,6 +226,14 @@ config EFI_CAPSULE_AUTHENTICATE Select this option if you want to enable capsule authentication

+config EFI_CAPSULE_MAX

•   int "Max value for capsule index"
  

•   default 15
  

•   range 0 65535
  

•   help
  

•     Select the max capsule index value used for capsule report
  

•     variables. This value is used to create CapsuleMax variable.
  

config EFI_DEVICE_PATH_TO_TEXT bool "Device path to text protocol" default y diff --git a/lib/efi_loader/efi_capsule.c b/lib/efi_loader/efi_capsule.c index 0997cd248f..d5d3ede7ae 100644 --- a/lib/efi_loader/efi_capsule.c +++ b/lib/efi_loader/efi_capsule.c @@ -45,17 +45,7 @@ const efi_guid_t fwu_guid_os_request_fw_accept = static struct efi_file_handle *bootdev_root; #endif

-/**

• • get_last_capsule - get the last capsule index
• • Retrieve the index of the capsule invoked last time from "CapsuleLast"
• • variable.
• • Return:
• • • ...

      0 - the last capsule index invoked

• • • 0xffff - on error, or no capsule invoked yet
• */

-static __maybe_unused unsigned int get_last_capsule(void) +static __maybe_unused unsigned int get_capsule_index(const u16 *variable_name) { u16 value16[11]; /* "CapsuleXXXX": non-null-terminated */ char value[5]; @@ -65,7 +55,7 @@ static __maybe_unused unsigned int get_last_capsule(void) int i;

    size = sizeof(value16);

•   ret = efi_get_variable_int(u"CapsuleLast", &efi_guid_capsule_report,
  

•   ret = efi_get_variable_int(variable_name, &efi_guid_capsule_report,
                               NULL, &size, value16, NULL);
    if (ret != EFI_SUCCESS || size != 22 ||
        u16_strncmp(value16, u"Capsule", 7))
  

@@ -84,6 +74,35 @@ err: return index; }

+/**

• • get_last_capsule - get the last capsule index
• • Retrieve the index of the capsule invoked last time from "CapsuleLast"
• • variable.
• • Return:
• • • ...

      0 - the last capsule index invoked

• • • 0xffff - on error, or no capsule invoked yet
• */

+static __maybe_unused unsigned int get_last_capsule(void) +{

•   return get_capsule_index(u"CapsuleLast");
  

+}

+/**

• • get_max_capsule - get the max capsule index
• • Retrieve the max capsule index value from "CapsuleMax" variable.
• • Return:
• • • ...

      0 - the max capsule index

• • • 0xffff - on error, or "CapsuleMax" variable does not exist
• */

+static __maybe_unused unsigned int get_max_capsule(void) +{

•   return get_capsule_index(u"CapsuleMax");
  

+}

/**

• set_capsule_result - set a result variable
• @capsule: Capsule

@@ -1290,7 +1309,7 @@ efi_status_t efi_launch_capsules(void) { struct efi_capsule_header *capsule = NULL; u16 **files;

•   unsigned int nfiles, index, i;
  

•   unsigned int nfiles, index, index_max, i;
    efi_status_t ret;
    bool capsule_update = true;
    bool update_status = true;
  

@@ -1299,6 +1318,7 @@ efi_status_t efi_launch_capsules(void) if (check_run_capsules() != EFI_SUCCESS) return EFI_SUCCESS;

•   index_max = get_max_capsule();
    index = get_last_capsule();
  
    /*
  

@@ -1317,7 +1337,7 @@ efi_status_t efi_launch_capsules(void) /* Launch capsules */ for (i = 0, ++index; i < nfiles; i++, index++) { log_debug("Applying %ls\n", files[i]);

•           if (index > 0xffff)
  

•           if (index > index_max)
                    index = 0;
            ret = efi_capsule_read_file(files[i], &capsule);
            if (ret == EFI_SUCCESS) {
  

diff --git a/lib/efi_loader/efi_setup.c b/lib/efi_loader/efi_setup.c index f0f01d3b1d..04da4cf14d 100644 --- a/lib/efi_loader/efi_setup.c +++ b/lib/efi_loader/efi_setup.c @@ -129,12 +129,17 @@ static efi_status_t efi_init_capsule(void) efi_status_t ret = EFI_SUCCESS;

    if (IS_ENABLED(CONFIG_EFI_HAVE_CAPSULE_SUPPORT)) {

•           u16 var_name16[12];
  

•           efi_create_indexed_name(var_name16, sizeof(var_name16),
  

•                                   "Capsule", CONFIG_EFI_CAPSULE_MAX);
  

•           ret = efi_set_variable_int(u"CapsuleMax",
                                       &efi_guid_capsule_report,
                                       EFI_VARIABLE_READ_ONLY |
                                       EFI_VARIABLE_BOOTSERVICE_ACCESS |
                                       EFI_VARIABLE_RUNTIME_ACCESS,
  

•                                      22, u"CapsuleFFFF", false);
  

•                                      22, var_name16, false);
            if (ret != EFI_SUCCESS)
                    printf("EFI: cannot initialize CapsuleMax variable\n");
    }
  

-- 2.25.1