[PATCH 5.15 234/913] KEYS: trusted: Fix trusted key backends when building as module

From: Greg Kroah-Hartman
Date: Tue Apr 05 2022 - 11:20:24 EST

From: Andreas Rammhold <andreas@xxxxxxxxxxx>

[ Upstream commit 969a26446bcd142faedfe8c6f41cd7668596c1fa ]

Before this commit the kernel could end up with no trusted key sources
even though both of the currently supported backends (TPM and TEE) were
compiled as modules. This manifested in the trusted key type not being
registered at all.

When checking if a CONFIG_… preprocessor variable is defined we only
test for the builtin (=y) case and not the module (=m) case. By using
the IS_REACHABLE() macro we do test for both cases.

Fixes: 5d0682be3189 ("KEYS: trusted: Add generic trusted keys framework")
Reviewed-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
Reviewed-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx>
Reviewed-by: Sumit Garg <sumit.garg@xxxxxxxxxx>
Signed-off-by: Andreas Rammhold <andreas@xxxxxxxxxxx>
Tested-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx>
Signed-off-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx>
Signed-off-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
security/keys/trusted-keys/trusted_core.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/security/keys/trusted-keys/trusted_core.c b/security/keys/trusted-keys/trusted_core.c
index d5c891d8d353..5b35f1b87644 100644
--- a/security/keys/trusted-keys/trusted_core.c
+++ b/security/keys/trusted-keys/trusted_core.c
@@ -27,10 +27,10 @@ module_param_named(source, trusted_key_source, charp, 0);
MODULE_PARM_DESC(source, "Select trusted keys source (tpm or tee)");

static const struct trusted_key_source trusted_key_sources[] = {
-#if defined(CONFIG_TCG_TPM)
{ "tpm", &trusted_key_tpm_ops },
-#if defined(CONFIG_TEE)
{ "tee", &trusted_key_tee_ops },