diff options
Diffstat (limited to '0003-x86-sgx-Add-wrapper-for-SGX2-EMODT-function.patch')
| -rw-r--r-- | 0003-x86-sgx-Add-wrapper-for-SGX2-EMODT-function.patch | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/0003-x86-sgx-Add-wrapper-for-SGX2-EMODT-function.patch b/0003-x86-sgx-Add-wrapper-for-SGX2-EMODT-function.patch new file mode 100644 index 000000000000..3c1cd27bf41d --- /dev/null +++ b/0003-x86-sgx-Add-wrapper-for-SGX2-EMODT-function.patch @@ -0,0 +1,49 @@ +From df48fa17c819d200e92b6862d39dc15f32c58e4e Mon Sep 17 00:00:00 2001 +From: Reinette Chatre <reinette.chatre@intel.com> +Date: Mon, 7 Feb 2022 16:45:25 -0800 +Subject: [PATCH 03/34] x86/sgx: Add wrapper for SGX2 EMODT function + +Add a wrapper for the EMODT ENCLS leaf function used to +change the type of an enclave page as maintained in the +SGX hardware's Enclave Page Cache Map (EPCM). + +EMODT: +1) Updates the EPCM page type of the enclave page. +2) Sets the MODIFIED bit in the EPCM entry of the enclave page. + This bit is reset by the enclave by invoking ENCLU leaf + function EACCEPT or EACCEPTCOPY. + +Access from within the enclave to the enclave page is not possible +while the MODIFIED bit is set. + +After changing the enclave page type by issuing EMODT the kernel +needs to collaborate with the hardware to ensure that no logical +processor continues to hold a reference to the changed page. This +is required to ensure no required security checks are circumvented +and is required for the enclave's EACCEPT/EACCEPTCOPY to succeed. +Ensuring that no references to the changed page remain is +accomplished with the ETRACK flow. + +Signed-off-by: Reinette Chatre <reinette.chatre@intel.com> +--- + arch/x86/kernel/cpu/sgx/encls.h | 6 ++++++ + 1 file changed, 6 insertions(+) + +diff --git a/arch/x86/kernel/cpu/sgx/encls.h b/arch/x86/kernel/cpu/sgx/encls.h +index 2b091912f038..7a1ecf704ec1 100644 +--- a/arch/x86/kernel/cpu/sgx/encls.h ++++ b/arch/x86/kernel/cpu/sgx/encls.h +@@ -221,4 +221,10 @@ static inline int __emodpr(struct sgx_secinfo *secinfo, void *addr) + return __encls_ret_2(EMODPR, secinfo, addr); + } + ++/* Change the type of an EPC page. */ ++static inline int __emodt(struct sgx_secinfo *secinfo, void *addr) ++{ ++ return __encls_ret_2(EMODT, secinfo, addr); ++} ++ + #endif /* _X86_ENCLS_H */ +-- +2.35.1 + |