From 26149b02021158248b13e323f06372d87f076883 Mon Sep 17 00:00:00 2001 From: Russell Currey Date: Fri, 10 Feb 2023 19:03:40 +1100 Subject: [PATCH] powerpc/secvar: Warn and error if multiple secvar ops are set The secvar code only supports one consumer at a time. Multiple consumers aren't possible at this point in time, but we'd want it to be obvious if it ever could happen. Signed-off-by: Russell Currey Co-developed-by: Andrew Donnellan Signed-off-by: Andrew Donnellan Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20230210080401.345462-6-ajd@linux.ibm.com --- arch/powerpc/include/asm/secvar.h | 4 ++-- arch/powerpc/kernel/secvar-ops.c | 10 ++++++++-- arch/powerpc/platforms/powernv/opal-secvar.c | 4 +--- 3 files changed, 11 insertions(+), 7 deletions(-) diff --git a/arch/powerpc/include/asm/secvar.h b/arch/powerpc/include/asm/secvar.h index 07ba36f..a2b5f22 100644 --- a/arch/powerpc/include/asm/secvar.h +++ b/arch/powerpc/include/asm/secvar.h @@ -21,11 +21,11 @@ struct secvar_operations { #ifdef CONFIG_PPC_SECURE_BOOT -extern void set_secvar_ops(const struct secvar_operations *ops); +int set_secvar_ops(const struct secvar_operations *ops); #else -static inline void set_secvar_ops(const struct secvar_operations *ops) { } +static inline int set_secvar_ops(const struct secvar_operations *ops) { return 0; } #endif diff --git a/arch/powerpc/kernel/secvar-ops.c b/arch/powerpc/kernel/secvar-ops.c index 6a29777..19172a2 100644 --- a/arch/powerpc/kernel/secvar-ops.c +++ b/arch/powerpc/kernel/secvar-ops.c @@ -8,10 +8,16 @@ #include #include +#include -const struct secvar_operations *secvar_ops __ro_after_init; +const struct secvar_operations *secvar_ops __ro_after_init = NULL; -void set_secvar_ops(const struct secvar_operations *ops) +int set_secvar_ops(const struct secvar_operations *ops) { + if (WARN_ON_ONCE(secvar_ops)) + return -EBUSY; + secvar_ops = ops; + + return 0; } diff --git a/arch/powerpc/platforms/powernv/opal-secvar.c b/arch/powerpc/platforms/powernv/opal-secvar.c index ef89861..4c0a3b0 100644 --- a/arch/powerpc/platforms/powernv/opal-secvar.c +++ b/arch/powerpc/platforms/powernv/opal-secvar.c @@ -113,9 +113,7 @@ static int opal_secvar_probe(struct platform_device *pdev) return -ENODEV; } - set_secvar_ops(&opal_secvar_ops); - - return 0; + return set_secvar_ops(&opal_secvar_ops); } static const struct of_device_id opal_secvar_match[] = { -- 2.7.4