Hello Andreas,
On 16.07.21 10:17, Andreas Rammhold wrote:
Before this commit the kernel could end up with no trusted key sources
even thought both of the currently supported backends (tpm & tee) were
compoiled as modules. This manifested in the trusted key type not being
registered at all.
I assume (TPM) trusted key module use worked before the TEE rework? If so,
an appropriate Fixes: Tag would then be in order.
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_ENABLE(…) macro we to test for both cases.
It looks to me like you could now provoke a link error if TEE is a module
and built-in trusted key core tries to link against trusted_key_tee_ops.
One solution for that IS_REACHABLE(). Another is to address the root cause,
which is the inflexible trusted keys Kconfig description:
- Trusted keys despite TEE support can still only be built when TCG_TPM is enabled
- There is no support to have TEE or TPM enabled without using those for
enabled trusted keys as well
- As you noticed, module build of the backend has issues
I addressed these three issues in a patch[1], a month ago, but have yet to
receive feedback.
[1]: https://lore.kernel.org/linux-integrity/f8285eb0135ba30c9d846cf9dd395d1f5f8b1efc.1624364386.git-series.a.fatoum@pengutronix.de/ (local)
Cheers,
Ahmad
quoted hunk ↗ jump to hunk
Signed-off-by: Andreas Rammhold <redacted>
---
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..fd640614b168 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)
+#if IS_ENABLED(CONFIG_TCG_TPM)
{ "tpm", &trusted_key_tpm_ops },
#endif
-#if defined(CONFIG_TEE)
+#if IS_ENABLED(CONFIG_TEE)
{ "tee", &trusted_key_tee_ops },
#endif
};
--
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