Misc documentation fixes/improvements
diff --git a/include/mbedtls/ecdh.h b/include/mbedtls/ecdh.h
index 6f3fe13..435ba00 100644
--- a/include/mbedtls/ecdh.h
+++ b/include/mbedtls/ecdh.h
@@ -40,6 +40,10 @@
 
 /**
  * \brief           ECDH context structure
+ *
+ * \warning         Performing multiple operations concurrently on the same
+ *                  ECDSA context is not supported; objects of this type
+ *                  should not be shared between multiple threads.
  */
 typedef struct
 {
@@ -159,7 +163,7 @@
  *                  ServerKeyEchange for static ECDH: import ECDH parameters
  *                  from a certificate's EC key information.)
  *
- * \param ctx       ECDH constext to set
+ * \param ctx       ECDH context to set
  * \param key       EC key to use
  * \param side      Is it our key (1) or the peer's key (0) ?
  *
diff --git a/include/mbedtls/ecdsa.h b/include/mbedtls/ecdsa.h
index ce94af8..3440a84 100644
--- a/include/mbedtls/ecdsa.h
+++ b/include/mbedtls/ecdsa.h
@@ -52,6 +52,10 @@
 
 /**
  * \brief           ECDSA context structure
+ *
+ * \warning         Performing multiple operations concurrently on the same
+ *                  ECDSA context is not supported; objects of this type
+ *                  should not be shared between multiple threads.
  */
 typedef mbedtls_ecp_keypair mbedtls_ecdsa_context;
 
diff --git a/include/mbedtls/x509_crt.h b/include/mbedtls/x509_crt.h
index 2f652b7..6831812 100644
--- a/include/mbedtls/x509_crt.h
+++ b/include/mbedtls/x509_crt.h
@@ -425,7 +425,7 @@
  * \param flags    result of the verification
  * \param f_vrfy   verification function
  * \param p_vrfy   verification parameter
- * \param rs_ctx   resart context
+ * \param rs_ctx   restart context
  *
  * \return         See \c mbedtls_crt_verify_with_profile(), or
  *                 MBEDTLS_ERR_ECP_IN_PROGRESS if maximum number of