[PATCH] tee: optee: release the supplicant when its device file is closed

[Arun Iyengar via B4 Relay <devnull+aiyengar1990.gmail.com@kernel.org>]

From: Arun Iyengar <aiyengar1990@gmail.com>

optee_supp_release() runs only on the context's last reference, which
RPC shared memory can hold. If tee-supplicant exits during an RPC, the
next request waits forever and a new tee-supplicant gets -EBUSY.

Detach the supplicant in .close_context instead.

Fixes: 217e0250cccb ("tee: use reference counting for tee_context")
Signed-off-by: Arun Iyengar <aiyengar1990@gmail.com>
---
Tested on an Orange Pi 5 (RK3588S, SMC ABI), 7.3-based KASAN + lockdep
kernel: tee-supplicant stopped and restarted during fTPM NV writes, no
hung task; the fTPM TA then stays dead until a reboot. FF-A is
build-tested only.

Developed with Claude (Anthropic), which wrote the code and the commit
message. I reviewed it.
---
 drivers/tee/optee/core.c          | 4 +---
 drivers/tee/optee/ffa_abi.c       | 3 ++-
 drivers/tee/optee/optee_private.h | 2 +-
 drivers/tee/optee/smc_abi.c       | 3 ++-
 4 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c
index a52c1f498b99..f446b40d7827 100644
--- a/drivers/tee/optee/core.c
+++ b/drivers/tee/optee/core.c
@@ -184,12 +184,10 @@ void optee_release(struct tee_context *ctx)
 	optee_release_helper(ctx, optee_close_session_helper);
 }
 
-void optee_release_supp(struct tee_context *ctx)
+void optee_close_context_supp(struct tee_context *ctx)
 {
 	struct optee *optee = tee_get_drvdata(ctx->teedev);
 
-	optee_release_helper(ctx, optee_close_session_helper);
-
 	optee_supp_release(&optee->supp);
 }
 
diff --git a/drivers/tee/optee/ffa_abi.c b/drivers/tee/optee/ffa_abi.c
index 702da7d98fbc..155ce9856de9 100644
--- a/drivers/tee/optee/ffa_abi.c
+++ b/drivers/tee/optee/ffa_abi.c
@@ -957,7 +957,8 @@ static const struct tee_driver_ops optee_ffa_supp_ops = {
 	.get_version = optee_ffa_get_version,
 	.get_tee_revision = optee_get_revision,
 	.open = optee_ffa_open,
-	.release = optee_release_supp,
+	.close_context = optee_close_context_supp,
+	.release = optee_release,
 	.supp_recv = optee_supp_recv,
 	.supp_send = optee_supp_send,
 	.shm_register = optee_ffa_shm_register, /* same as for clnt ops */
diff --git a/drivers/tee/optee/optee_private.h b/drivers/tee/optee/optee_private.h
index 94a4f251f5cf..6495e0f07deb 100644
--- a/drivers/tee/optee/optee_private.h
+++ b/drivers/tee/optee/optee_private.h
@@ -370,7 +370,7 @@ void optee_set_dev_group(struct optee *optee);
 void optee_remove_common(struct optee *optee);
 int optee_open(struct tee_context *ctx, bool cap_memref_null);
 void optee_release(struct tee_context *ctx);
-void optee_release_supp(struct tee_context *ctx);
+void optee_close_context_supp(struct tee_context *ctx);
 
 static inline void optee_from_msg_param_value(struct tee_param *p, u32 attr,
 					      const struct optee_msg_param *mp)
diff --git a/drivers/tee/optee/smc_abi.c b/drivers/tee/optee/smc_abi.c
index 51624443359b..0278dc6b0119 100644
--- a/drivers/tee/optee/smc_abi.c
+++ b/drivers/tee/optee/smc_abi.c
@@ -1264,7 +1264,8 @@ static const struct tee_driver_ops optee_supp_ops = {
 	.get_version = optee_get_version,
 	.get_tee_revision = optee_get_revision,
 	.open = optee_smc_open,
-	.release = optee_release_supp,
+	.close_context = optee_close_context_supp,
+	.release = optee_release,
 	.supp_recv = optee_supp_recv,
 	.supp_send = optee_supp_send,
 	.shm_register = optee_shm_register_supp,

---
base-commit: e21989d08e0d6abacfff71387d0cb36dd96a4079
change-id: 20261115-optee-supp-close-45df0ffe66b3

Best regards,
--  
Arun Iyengar <aiyengar1990@gmail.com>