PowerNV secure boot defines different IMA policies based on the secure boot state of the system.
This patch defines a function to detect the secure boot state of the system. Signed-off-by: Nayna Jain <na...@linux.ibm.com> --- arch/powerpc/include/asm/secboot.h | 21 ++++++++ arch/powerpc/platforms/powernv/Makefile | 2 +- arch/powerpc/platforms/powernv/secboot.c | 61 ++++++++++++++++++++++++ 3 files changed, 83 insertions(+), 1 deletion(-) create mode 100644 arch/powerpc/include/asm/secboot.h create mode 100644 arch/powerpc/platforms/powernv/secboot.c diff --git a/arch/powerpc/include/asm/secboot.h b/arch/powerpc/include/asm/secboot.h new file mode 100644 index 000000000000..1904fb4a3352 --- /dev/null +++ b/arch/powerpc/include/asm/secboot.h @@ -0,0 +1,21 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * PowerPC secure boot definitions + * + * Copyright (C) 2019 IBM Corporation + * Author: Nayna Jain <na...@linux.ibm.com> + * + */ +#ifndef POWERPC_SECBOOT_H +#define POWERPC_SECBOOT_H + +#if defined(CONFIG_OPAL_SECVAR) +extern bool get_powerpc_sb_mode(void); +#else +static inline bool get_powerpc_sb_mode(void) +{ + return false; +} +#endif + +#endif diff --git a/arch/powerpc/platforms/powernv/Makefile b/arch/powerpc/platforms/powernv/Makefile index 6651c742e530..6f4af607a915 100644 --- a/arch/powerpc/platforms/powernv/Makefile +++ b/arch/powerpc/platforms/powernv/Makefile @@ -16,4 +16,4 @@ obj-$(CONFIG_PERF_EVENTS) += opal-imc.o obj-$(CONFIG_PPC_MEMTRACE) += memtrace.o obj-$(CONFIG_PPC_VAS) += vas.o vas-window.o vas-debug.o obj-$(CONFIG_OCXL_BASE) += ocxl.o -obj-$(CONFIG_OPAL_SECVAR) += opal-secvar.o +obj-$(CONFIG_OPAL_SECVAR) += opal-secvar.o secboot.o diff --git a/arch/powerpc/platforms/powernv/secboot.c b/arch/powerpc/platforms/powernv/secboot.c new file mode 100644 index 000000000000..9199e520ebed --- /dev/null +++ b/arch/powerpc/platforms/powernv/secboot.c @@ -0,0 +1,61 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2019 IBM Corporation + * Author: Nayna Jain <na...@linux.ibm.com> + * + * secboot.c + * - util function to get powerpc secboot state + */ +#include <linux/uuid.h> +#include <asm/opal.h> +#include <asm/secboot.h> +#include <asm/opal-secvar.h> + +bool get_powerpc_sb_mode(void) +{ + u8 secure_boot_name[] = "SecureBoot"; + u8 setup_mode_name[] = "SetupMode"; + u8 secboot, setupmode; + unsigned long size = sizeof(secboot); + int status; + unsigned long version; + + status = opal_variable_version(&version); + if ((status != OPAL_SUCCESS) || (version != BACKEND_TC_COMPAT_V1)) { + pr_info("secboot: error retrieving compatible backend\n"); + return false; + } + + status = opal_get_variable(secure_boot_name, sizeof(secure_boot_name), + NULL, NULL, &secboot, &size); + + /* + * For now assume all failures reading the SecureBoot variable implies + * secure boot is not enabled. Later differentiate failure types. + */ + if (status != OPAL_SUCCESS) { + secboot = 0; + setupmode = 0; + goto out; + } + + size = sizeof(setupmode); + status = opal_get_variable(setup_mode_name, sizeof(setup_mode_name), + NULL, NULL, &setupmode, &size); + + /* + * Failure to read the SetupMode variable does not prevent + * secure boot mode + */ + if (status != OPAL_SUCCESS) + setupmode = 0; + +out: + if ((secboot == 0) || (setupmode == 1)) { + pr_info("secboot: secureboot mode disabled\n"); + return false; + } + + pr_info("secboot: secureboot mode enabled\n"); + return true; +} -- 2.20.1