@@ -65,17 +65,22 @@ enum sgx_encls_function {
/**
* enum sgx_return_code - The return code type for ENCLS, ENCLU and ENCLV
+ * %SGX_EPC_PAGE_CONFLICT: Page is being written by other ENCLS function.
* %SGX_NOT_TRACKED: Previous ETRACK's shootdown sequence has not
* been completed yet.
* %SGX_CHILD_PRESENT SECS has child pages present in the EPC.
* %SGX_INVALID_EINITTOKEN: EINITTOKEN is invalid and enclave signer's
* public key does not match IA32_SGXLEPUBKEYHASH.
+ * %SGX_PAGE_NOT_MODIFIABLE: The EPC page cannot be modified because it
+ * is in the PENDING or MODIFIED state.
* %SGX_UNMASKED_EVENT: An unmasked event, e.g. INTR, was received
*/
enum sgx_return_code {
+ SGX_EPC_PAGE_CONFLICT = 7,
SGX_NOT_TRACKED = 11,
SGX_CHILD_PRESENT = 13,
SGX_INVALID_EINITTOKEN = 16,
+ SGX_PAGE_NOT_MODIFIABLE = 20,
SGX_UNMASKED_EVENT = 128,
};
@@ -215,4 +215,10 @@ static inline int __ewb(struct sgx_pageinfo *pginfo, void *addr,
return __encls_ret_3(EWB, pginfo, addr, va);
}
+/* Restrict the EPCM permissions of an EPC page. */
+static inline int __emodpr(struct sgx_secinfo *secinfo, void *addr)
+{
+ return __encls_ret_2(EMODPR, secinfo, addr);
+}
+
#endif /* _X86_ENCLS_H */
Add a wrapper for the EMODPR ENCLS leaf function used to restrict enclave page permissions as maintained in the SGX hardware's Enclave Page Cache Map (EPCM). EMODPR: 1) Updates the EPCM permissions of an enclave page by treating the new permissions as a mask - supplying a value that relaxes EPCM permissions has no effect. 2) Sets the PR bit in the EPCM entry of the enclave page to indicate that permission restriction is in progress. The bit is reset by the enclave by invoking ENCLU leaf function EACCEPT or EACCEPTCOPY. The enclave may access the page throughout the entire process if conforming to the EPCM permissions for the enclave page. After performing the permission restriction by issuing EMODPR the kernel needs to collaborate with the hardware to ensure that all logical processors sees the new restricted permissions. This is required for the enclave's EACCEPT/EACCEPTCOPY to succeed and is accomplished with the ETRACK flow. Expand enum sgx_return_code with the possible EMODPR return values. Signed-off-by: Reinette Chatre <reinette.chatre@intel.com> --- Changes since V1: - Split original patch ("x86/sgx: Add wrappers for SGX2 functions") in three to introduce the SGX2 functions separately (Jarkko). - Rewrite commit message to include how the EPCM within the hardware is changed by the SGX2 function as well as the calling conditions (Jarkko). - Make short description more specific to which permissions (EPCM permissions) the function modifies. arch/x86/include/asm/sgx.h | 5 +++++ arch/x86/kernel/cpu/sgx/encls.h | 6 ++++++ 2 files changed, 11 insertions(+)