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: -.Lskip_exception_info: - mov $(-EFAULT), %eax + /* Set the exit_reason and exception info. */ + movl $(-EFAULT), EXIT_REASON_OFFSET(%rbx) -- Jethro Beekman | Fortanix
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