From 4429393b5a41557c744b1fab912a32b34bee8d38 Mon Sep 17 00:00:00 2001 From: Etienne Carriere Date: Thu, 16 Feb 2023 18:21:41 +0100 Subject: [PATCH] efi_loader: set CapsuleMax from CONFIG_EFI_CAPSULE_MAX Adds CONFIG_EFI_CAPSULE_MAX to configure the max index value used in EFI capsule reports. Prior to this change is the hard coded value was 65535 which would exceed available storage for variables. Now the default value is 15 which should work fine with most systems. Signed-off-by: Etienne Carriere --- 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 c05a54df16..c5835e6ef6 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 69aaefab63..58d4e13402 100644 --- a/lib/efi_loader/efi_setup.c +++ b/lib/efi_loader/efi_setup.c @@ -130,12 +130,17 @@ 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"); } -- 2.39.5