diff options
Diffstat (limited to 'arch/x86/include/uapi')
| -rw-r--r-- | arch/x86/include/uapi/asm/sgx.h | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/arch/x86/include/uapi/asm/sgx.h b/arch/x86/include/uapi/asm/sgx.h index c32210235bf5..791e45334a4a 100644 --- a/arch/x86/include/uapi/asm/sgx.h +++ b/arch/x86/include/uapi/asm/sgx.h @@ -74,4 +74,95 @@ struct sgx_enclave_provision { __u64 fd; }; +struct sgx_enclave_run; + +/** + * typedef sgx_enclave_user_handler_t - Exit handler function accepted by + * __vdso_sgx_enter_enclave() + * @run: The run instance given by the caller + * + * The register parameters contain the snapshot of their values at enclave + * exit. An invalid ENCLU function number will cause -EINVAL to be returned + * to the caller. + * + * Return: + * - <= 0: The given value is returned back to the caller. + * - > 0: ENCLU function to invoke, either EENTER or ERESUME. + */ +typedef int (*sgx_enclave_user_handler_t)(long rdi, long rsi, long rdx, + long rsp, long r8, long r9, + struct sgx_enclave_run *run); + +/** + * struct sgx_enclave_run - the execution context of __vdso_sgx_enter_enclave() + * @tcs: TCS used to enter the enclave + * @function: The last seen ENCLU function (EENTER, ERESUME or EEXIT) + * @exception_vector: The interrupt vector of the exception + * @exception_error_code: The exception error code pulled out of the stack + * @exception_addr: The address that triggered the exception + * @user_handler: User provided callback run on exception + * @user_data: Data passed to the user handler + * @reserved Reserved for future extensions + * + * If @user_handler is provided, the handler will be invoked on all return paths + * of the normal flow. The user handler may transfer control, e.g. via a + * longjmp() call or a C++ exception, without returning to + * __vdso_sgx_enter_enclave(). + */ +struct sgx_enclave_run { + __u64 tcs; + __u32 function; + __u16 exception_vector; + __u16 exception_error_code; + __u64 exception_addr; + __u64 user_handler; + __u64 user_data; + __u8 reserved[216]; +}; + +/** + * typedef vdso_sgx_enter_enclave_t - Prototype for __vdso_sgx_enter_enclave(), + * a vDSO function to enter an SGX enclave. + * @rdi: Pass-through value for RDI + * @rsi: Pass-through value for RSI + * @rdx: Pass-through value for RDX + * @function: ENCLU function, must be EENTER or ERESUME + * @r8: Pass-through value for R8 + * @r9: Pass-through value for R9 + * @run: struct sgx_enclave_run, must be non-NULL + * + * NOTE: __vdso_sgx_enter_enclave() does not ensure full compliance with the + * x86-64 ABI, e.g. doesn't handle XSAVE state. Except for non-volatile + * general purpose registers, EFLAGS.DF, and RSP alignment, preserving/setting + * state in accordance with the x86-64 ABI is the responsibility of the enclave + * and its runtime, i.e. __vdso_sgx_enter_enclave() cannot be called from C + * code without careful consideration by both the enclave and its runtime. + * + * All general purpose registers except RAX, RBX and RCX are passed as-is to the + * enclave. RAX, RBX and RCX are consumed by EENTER and ERESUME and are loaded + * with @function, asynchronous exit pointer, and @run.tcs respectively. + * + * RBP and the stack are used to anchor __vdso_sgx_enter_enclave() to the + * pre-enclave state, e.g. to retrieve @run.exception and @run.user_handler + * after an enclave exit. All other registers are available for use by the + * enclave and its runtime, e.g. an enclave can push additional data onto the + * stack (and modify RSP) to pass information to the optional user handler (see + * below). + * + * Most exceptions reported on ENCLU, including those that occur within the + * enclave, are fixed up and reported synchronously instead of being delivered + * via a standard signal. Debug Exceptions (#DB) and Breakpoints (#BP) are + * never fixed up and are always delivered via standard signals. On synchrously + * reported exceptions, -EFAULT is returned and details about the exception are + * recorded in @run.exception, the optional sgx_enclave_exception struct. + * + * Return: + * - 0: ENCLU function was successfully executed. + * - -EINVAL: Invalid ENCL number (neither EENTER nor ERESUME). + */ +typedef int (*vdso_sgx_enter_enclave_t)(unsigned long rdi, unsigned long rsi, + unsigned long rdx, unsigned int function, + unsigned long r8, unsigned long r9, + struct sgx_enclave_run *run); + #endif /* _UAPI_ASM_X86_SGX_H */ |