[PATCH v5 05/25] powerpc/secvar: Warn and error if multiple secvar ops are set
From: Andrew Donnellan <hidden>
Date: 2023-01-31 06:41:59
Also in:
linux-integrity, lkml
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
From: Russell Currey <redacted>
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 <redacted>
Co-developed-by: Andrew Donnellan <redacted>
Signed-off-by: Andrew Donnellan <redacted>
---
v4: Return an error and don't actually try to set secvar_operations if the
warning is triggered (npiggin)
v5: Drop "extern" to fix a checkpatch check (snowpatch)
---
arch/powerpc/include/asm/secvar.h | 4 ++--
arch/powerpc/kernel/secvar-ops.c | 8 ++++++--
arch/powerpc/platforms/powernv/opal-secvar.c | 4 +---
3 files changed, 9 insertions(+), 7 deletions(-)
diff --git a/arch/powerpc/include/asm/secvar.h b/arch/powerpc/include/asm/secvar.h
index 07ba36f868a7..a2b5f2203dc5 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 6a29777d6a2d..9c8dd4e7c270 100644
--- a/arch/powerpc/kernel/secvar-ops.c
+++ b/arch/powerpc/kernel/secvar-ops.c@@ -8,10 +8,14 @@ #include <linux/cache.h> #include <asm/secvar.h> +#include <asm/bug.h> -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 -1; secvar_ops = ops; + return 0; }
diff --git a/arch/powerpc/platforms/powernv/opal-secvar.c b/arch/powerpc/platforms/powernv/opal-secvar.c
index ef89861569e0..4c0a3b030fe0 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[] = {
--
2.39.1