On Tue, Aug 25, 2020 at 09:41:19AM +0200, Jethro Beekman wrote: > On 2020-08-25 09:38, Sean Christopherson wrote: > > 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? > > > > No, I'm just bad at reading patches without syntax highlighting. This is fine > as is. Sorry for the confusion. No worries. Removing the -errno line is actually wrong, the vDSO still returns -errno if the userspace callback returns a negative value.
