From 50a466bf3e6f6f177dc0aeefa46a2f8927075a1d Mon Sep 17 00:00:00 2001 From: Andrew Donnellan Date: Fri, 10 Feb 2023 19:03:46 +1100 Subject: [PATCH] powerpc/secvar: Allow backend to populate static list of variable names Currently, the list of variables is populated by calling secvar_ops->get_next() repeatedly, which is explicitly modelled on the OPAL API (including the keylen parameter). For the upcoming PLPKS backend, we have a static list of variable names. It is messy to fit that into get_next(), so instead, let the backend put a NULL-terminated array of variable names into secvar_ops->var_names, which will be used if get_next() is undefined. Signed-off-by: Andrew Donnellan Signed-off-by: Russell Currey Reviewed-by: Stefan Berger Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20230210080401.345462-12-ajd@linux.ibm.com --- arch/powerpc/include/asm/secvar.h | 4 +++ arch/powerpc/kernel/secvar-sysfs.c | 69 ++++++++++++++++++++++++++------------ 2 files changed, 52 insertions(+), 21 deletions(-) diff --git a/arch/powerpc/include/asm/secvar.h b/arch/powerpc/include/asm/secvar.h index 011a53a..4828e0a 100644 --- a/arch/powerpc/include/asm/secvar.h +++ b/arch/powerpc/include/asm/secvar.h @@ -21,6 +21,10 @@ struct secvar_operations { ssize_t (*format)(char *buf, size_t bufsize); int (*max_size)(u64 *max_size); const struct attribute **config_attrs; + + // NULL-terminated array of fixed variable names + // Only used if get_next() isn't provided + const char * const *var_names; }; #ifdef CONFIG_PPC_SECURE_BOOT diff --git a/arch/powerpc/kernel/secvar-sysfs.c b/arch/powerpc/kernel/secvar-sysfs.c index 7df32be..bfb19f2 100644 --- a/arch/powerpc/kernel/secvar-sysfs.c +++ b/arch/powerpc/kernel/secvar-sysfs.c @@ -157,9 +157,31 @@ static int secvar_sysfs_config(struct kobject *kobj) return 0; } -static int secvar_sysfs_load(void) +static int add_var(const char *name) { struct kobject *kobj; + int rc; + + kobj = kzalloc(sizeof(*kobj), GFP_KERNEL); + if (!kobj) + return -ENOMEM; + + kobject_init(kobj, &secvar_ktype); + + rc = kobject_add(kobj, &secvar_kset->kobj, "%s", name); + if (rc) { + pr_warn("kobject_add error %d for attribute: %s\n", rc, + name); + kobject_put(kobj); + return rc; + } + + kobject_uevent(kobj, KOBJ_ADD); + return 0; +} + +static int secvar_sysfs_load(void) +{ u64 namesize = 0; char *name; int rc; @@ -179,31 +201,28 @@ static int secvar_sysfs_load(void) break; } - kobj = kzalloc(sizeof(*kobj), GFP_KERNEL); - if (!kobj) { - rc = -ENOMEM; - break; - } - - kobject_init(kobj, &secvar_ktype); - - rc = kobject_add(kobj, &secvar_kset->kobj, "%s", name); - if (rc) { - pr_warn("kobject_add error %d for attribute: %s\n", rc, - name); - kobject_put(kobj); - kobj = NULL; - } - - if (kobj) - kobject_uevent(kobj, KOBJ_ADD); - + rc = add_var(name); } while (!rc); kfree(name); return rc; } +static int secvar_sysfs_load_static(void) +{ + const char * const *name_ptr = secvar_ops->var_names; + int rc; + + while (*name_ptr) { + rc = add_var(*name_ptr); + if (rc) + return rc; + name_ptr++; + } + + return 0; +} + static int secvar_sysfs_init(void) { int rc; @@ -245,7 +264,15 @@ static int secvar_sysfs_init(void) goto err; } - secvar_sysfs_load(); + if (secvar_ops->get_next) + rc = secvar_sysfs_load(); + else + rc = secvar_sysfs_load_static(); + + if (rc) { + pr_err("Failed to create variable attributes\n"); + goto err; + } return 0; err: -- 2.7.4