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authorCedric Neveux <cedric.neveux@nxp.com>2019-03-04 08:54:23 +0100
committerJens Wiklander <jens.wiklander@linaro.org>2020-08-21 08:55:13 +0200
commitba171d3f0850003216fd1a85190d17b1feddb961 (patch)
tree32c534e8e4d18d1e2a9350b7333f53325137c209 /drivers/tee
parentLinux 5.9-rc1 (diff)
downloadlinux-ba171d3f0850003216fd1a85190d17b1feddb961.tar.xz
linux-ba171d3f0850003216fd1a85190d17b1feddb961.zip
driver: tee: Handle NULL pointer indication from client
TEE Client introduce a new capability "TEE_GEN_CAP_MEMREF_NULL" to handle the support of the shared memory buffer with a NULL pointer. This capability depends on TEE Capabilities and driver support. Driver and TEE exchange capabilities at driver initialization. Signed-off-by: Michael Whitfield <michael.whitfield@nxp.com> Signed-off-by: Cedric Neveux <cedric.neveux@nxp.com> Reviewed-by: Joakim Bech <joakim.bech@linaro.org> Tested-by: Joakim Bech <joakim.bech@linaro.org> (QEMU) Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
Diffstat (limited to 'drivers/tee')
-rw-r--r--drivers/tee/optee/core.c7
-rw-r--r--drivers/tee/optee/optee_smc.h3
-rw-r--r--drivers/tee/tee_core.c49
3 files changed, 41 insertions, 18 deletions
diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c
index b373b1b08b6d..cf4718c6d35d 100644
--- a/drivers/tee/optee/core.c
+++ b/drivers/tee/optee/core.c
@@ -216,6 +216,8 @@ static void optee_get_version(struct tee_device *teedev,
if (optee->sec_caps & OPTEE_SMC_SEC_CAP_DYNAMIC_SHM)
v.gen_caps |= TEE_GEN_CAP_REG_MEM;
+ if (optee->sec_caps & OPTEE_SMC_SEC_CAP_MEMREF_NULL)
+ v.gen_caps |= TEE_GEN_CAP_MEMREF_NULL;
*vers = v;
}
@@ -262,6 +264,11 @@ static int optee_open(struct tee_context *ctx)
mutex_init(&ctxdata->mutex);
INIT_LIST_HEAD(&ctxdata->sess_list);
+ if (optee->sec_caps & OPTEE_SMC_SEC_CAP_MEMREF_NULL)
+ ctx->cap_memref_null = true;
+ else
+ ctx->cap_memref_null = false;
+
ctx->data = ctxdata;
return 0;
}
diff --git a/drivers/tee/optee/optee_smc.h b/drivers/tee/optee/optee_smc.h
index c72122d9c997..777ad54d4c2c 100644
--- a/drivers/tee/optee/optee_smc.h
+++ b/drivers/tee/optee/optee_smc.h
@@ -215,6 +215,9 @@ struct optee_smc_get_shm_config_result {
*/
#define OPTEE_SMC_SEC_CAP_DYNAMIC_SHM BIT(2)
+/* Secure world supports Shared Memory with a NULL buffer reference */
+#define OPTEE_SMC_SEC_CAP_MEMREF_NULL BIT(4)
+
#define OPTEE_SMC_FUNCID_EXCHANGE_CAPABILITIES 9
#define OPTEE_SMC_EXCHANGE_CAPABILITIES \
OPTEE_SMC_FAST_CALL_VAL(OPTEE_SMC_FUNCID_EXCHANGE_CAPABILITIES)
diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c
index 64637e09a095..ce0f0309b6ac 100644
--- a/drivers/tee/tee_core.c
+++ b/drivers/tee/tee_core.c
@@ -383,25 +383,38 @@ static int params_from_user(struct tee_context *ctx, struct tee_param *params,
case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
/*
- * If we fail to get a pointer to a shared memory
- * object (and increase the ref count) from an
- * identifier we return an error. All pointers that
- * has been added in params have an increased ref
- * count. It's the callers responibility to do
- * tee_shm_put() on all resolved pointers.
+ * If a NULL pointer is passed to a TA in the TEE,
+ * the ip.c IOCTL parameters is set to TEE_MEMREF_NULL
+ * indicating a NULL memory reference.
*/
- shm = tee_shm_get_from_id(ctx, ip.c);
- if (IS_ERR(shm))
- return PTR_ERR(shm);
-
- /*
- * Ensure offset + size does not overflow offset
- * and does not overflow the size of the referred
- * shared memory object.
- */
- if ((ip.a + ip.b) < ip.a ||
- (ip.a + ip.b) > shm->size) {
- tee_shm_put(shm);
+ if (ip.c != TEE_MEMREF_NULL) {
+ /*
+ * If we fail to get a pointer to a shared
+ * memory object (and increase the ref count)
+ * from an identifier we return an error. All
+ * pointers that has been added in params have
+ * an increased ref count. It's the callers
+ * responibility to do tee_shm_put() on all
+ * resolved pointers.
+ */
+ shm = tee_shm_get_from_id(ctx, ip.c);
+ if (IS_ERR(shm))
+ return PTR_ERR(shm);
+
+ /*
+ * Ensure offset + size does not overflow
+ * offset and does not overflow the size of
+ * the referred shared memory object.
+ */
+ if ((ip.a + ip.b) < ip.a ||
+ (ip.a + ip.b) > shm->size) {
+ tee_shm_put(shm);
+ return -EINVAL;
+ }
+ } else if (ctx->cap_memref_null) {
+ /* Pass NULL pointer to OP-TEE */
+ shm = NULL;
+ } else {
return -EINVAL;
}