On Tue, Aug 25, 2020 at 09:36:15AM +0200, Jethro Beekman wrote: > On 2020-08-25 01:54, Sean Christopherson wrote: > > On Mon, Aug 24, 2020 at 03:36:11PM +0200, Jethro Beekman wrote: > >> On 2020-08-18 06:24, Sean Christopherson wrote: > >>> /** > >>> * __vdso_sgx_enter_enclave() - Enter an SGX enclave > >>> @@ -119,16 +153,14 @@ typedef int (*sgx_enclave_exit_handler_t)(long rdi, long rsi, long rdx, > >>> * @leaf: ENCLU leaf, must be EENTER or ERESUME > >>> * @r8: Pass-through value for R8 > >>> * @r9: Pass-through value for R9 > >>> - * @tcs: TCS, must be non-NULL > >>> - * @e: Optional struct sgx_enclave_exception instance > >>> - * @handler: Optional enclave exit handler > >>> + * @r: 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 explicitly clear EFLAGS.DF after EEXIT. Except for > >>> - * non-volatile general purpose registers, 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. > >>> + * 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 > >>> @@ -160,16 +192,12 @@ typedef int (*sgx_enclave_exit_handler_t)(long rdi, long rsi, long rdx, > >>> * without returning to __vdso_sgx_enter_enclave(). > >>> * > >>> * Return: > >>> - * 0 on success, > >>> + * 0 on success (ENCLU reached), > >>> * -EINVAL if ENCLU leaf is not allowed, > >>> - * -EFAULT if an exception occurs on ENCLU or within the enclave > >>> - * -errno for all other negative values returned by the userspace exit handler > >>> */ > >>> typedef int (*vdso_sgx_enter_enclave_t)(unsigned long rdi, unsigned long rsi, > >>> unsigned long rdx, unsigned int leaf, > >>> unsigned long r8, unsigned long r9, > >>> - void *tcs, > >>> - struct sgx_enclave_exception *e, > >>> - sgx_enclave_exit_handler_t handler); > >>> + struct sgx_enclave_run *r); > >>> > >>> #endif /* _UAPI_ASM_X86_SGX_H */ > >>> > >> > >> I think this should return void now, not int? Then, the “return” section of > >> the documentation is also no longer correct. > > > > No, it returns -EINVAL if the leaf is bogus (and if unsupported flags are > > specified, if a @flags param is ever added). > > > > Ok, but if I read the code correctly, contrary to the docs, -EFAULT is not > returned but passed in struct sgx_enclave_run: The -EFAULT and -errno lines are removed from the "Return:" section of the above documentation. Did I miss one? > > -.Lskip_exception_info: > - mov $(-EFAULT), %eax > + /* Set the exit_reason and exception info. */ > + movl $(-EFAULT), EXIT_REASON_OFFSET(%rbx) > > -- > Jethro Beekman | Fortanix >
