Do not overload sgx_enclave_exception.leaf to indicate success vs. failure, i.e. EEXIT vs. fault. Instead, explicitly pass what would be the return value (from __vdso_sgx_enter_enclave()) to userspace's exit handler. Passing the return values makes the two flows (exit handler vs. no exit handler) symmetric and provides the exit handler with a fault indicator without requiring struct sgx_enclave_exception. Opportunistically fix the typedef for the callback to reference struct sgx_enclave_exception instead of the non-existent sgx_enclave_exinfo. Intentionally leave the local labels out of whack, they'll be cleaned up in a future patch. Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx> --- arch/x86/entry/vdso/vsgx_enter_enclave.S | 33 +++++++++++------------- 1 file changed, 15 insertions(+), 18 deletions(-) diff --git a/arch/x86/entry/vdso/vsgx_enter_enclave.S b/arch/x86/entry/vdso/vsgx_enter_enclave.S index 96726000aa27..06e18a2836de 100644 --- a/arch/x86/entry/vdso/vsgx_enter_enclave.S +++ b/arch/x86/entry/vdso/vsgx_enter_enclave.S @@ -53,11 +53,11 @@ * -EFAULT if ENCL or the enclave faults or non-positive value is returned * from the callback. */ -typedef int (*sgx_callback)(long rdi, long rsi, long rdx, - struct sgx_enclave_exinfo *exinfo, long r8, - long r9, void *tcs, long ursp); +typedef int (*sgx_callback)(long rdi, long rsi, long rdx, int ret, + long r8, long r9, void *tcs, long ursp, + struct sgx_enclave_exception *e); int __vdso_sgx_enter_enclave(int leaf, void *tcs, - struct sgx_enclave_exinfo *exinfo, + struct sgx_enclave_exception *e, sgx_callback callback); #endif ENTRY(__vdso_sgx_enter_enclave) @@ -83,21 +83,12 @@ ENTRY(__vdso_sgx_enter_enclave) 2: enclu /* EEXIT path */ - xor %ebx, %ebx -3: mov 0x18(%rbp), %rcx - jrcxz 4f - mov %eax, EX_LEAF(%rcx) - jnc 4f - mov %di, EX_TRAPNR(%rcx) - mov %si, EX_ERROR_CODE(%rcx) - mov %rdx, EX_ADDRESS(%rcx) + xor %eax, %eax +3: mov %eax, %ecx -4: /* Call *callback if supplied */ + /* Call *callback if supplied */ mov 0x20(%rbp), %rax test %rax, %rax - /* At this point, %ebx holds the effective return value, which shall be - * returned if no callback is specified */ - cmovz %rbx, %rax jz 7f /* Align stack per x86_64 ABI. The original %rsp is saved in %rbx to be * restored after *callback returns. */ @@ -106,6 +97,7 @@ ENTRY(__vdso_sgx_enter_enclave) /* Clear RFLAGS.DF per x86_64 ABI */ cld /* Parameters for *callback */ + push 0x18(%rbp) push %rbx push 0x10(%rbp) /* Call *%rax via retpoline */ @@ -126,8 +118,13 @@ ENTRY(__vdso_sgx_enter_enclave) ret 5: /* Exception path */ - mov $-EFAULT, %ebx - stc + mov 0x18(%rbp), %rcx + jrcxz 52f + mov %eax, EX_LEAF(%rcx) + mov %di, EX_TRAPNR(%rcx) + mov %si, EX_ERROR_CODE(%rcx) + mov %rdx, EX_ADDRESS(%rcx) +52: mov $-EFAULT, %eax jmp 3b 6: /* Unsupported ENCLU leaf */ -- 2.22.0
