From: Sean Christopherson <sean.j.christopherson@intel.com>
To: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: linux-sgx@vger.kernel.org
Subject: [PATCH for_v23 02/16] x86/vdso: sgx: Do not use exception info to pass success/failure
Date: Mon, 7 Oct 2019 21:45:59 -0700 [thread overview]
Message-ID: <20191008044613.12350-3-sean.j.christopherson@intel.com> (raw)
In-Reply-To: <20191008044613.12350-1-sean.j.christopherson@intel.com>
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@intel.com>
---
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
next prev parent reply other threads:[~2019-10-08 4:46 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-08 4:45 [PATCH for_v23 00/16] x86/vdso: sgx: Major vDSO cleanup Sean Christopherson
2019-10-08 4:45 ` [PATCH for_v23 01/16] x86/vdso: sgx: Drop the pseudocode "documentation" Sean Christopherson
2019-10-08 4:45 ` Sean Christopherson [this message]
2019-10-08 4:46 ` [PATCH for_v23 03/16] x86/vdso: sgx: Rename the enclave exit handler typedef Sean Christopherson
2019-10-08 4:46 ` [PATCH for_v23 04/16] x86/vdso: sgx: Move enclave exit handler declaration to UAPI header Sean Christopherson
2019-10-08 4:46 ` [PATCH for_v23 05/16] x86/vdso: sgx: Add comment regarding kernel-doc shenanigans Sean Christopherson
2019-10-08 4:46 ` [PATCH for_v23 06/16] x86/vdso: sgx: Rewrite __vdso_sgx_enter_enclave() function comment Sean Christopherson
2019-10-08 4:46 ` [PATCH for_v23 07/16] selftests/x86: Fix linker warning in SGX selftest Sean Christopherson
2019-10-08 4:46 ` [PATCH for_v23 08/16] selftests/x86/sgx: Use getauxval() to retrieve the vDSO base address Sean Christopherson
2019-10-08 4:46 ` [PATCH for_v23 09/16] selftests/x86/sgx: Add helper function and macros to assert results Sean Christopherson
2019-10-08 4:46 ` [PATCH for_v23 10/16] selftests/x86/sgx: Handle setup failures via test assertions Sean Christopherson
2019-10-15 10:16 ` Jarkko Sakkinen
2019-10-15 10:24 ` Jarkko Sakkinen
2019-10-15 10:25 ` Jarkko Sakkinen
2019-10-15 11:03 ` Jarkko Sakkinen
2019-10-15 16:27 ` Sean Christopherson
2019-10-16 10:20 ` Jarkko Sakkinen
2019-10-16 20:21 ` Sean Christopherson
2019-10-15 16:18 ` Sean Christopherson
2019-10-16 10:19 ` Jarkko Sakkinen
2019-10-08 4:46 ` [PATCH for_v23 11/16] selftests/x86/sgx: Sanitize the types for sgx_call()'s input params Sean Christopherson
2019-10-08 4:46 ` [PATCH for_v23 12/16] selftests/x86/sgx: Move existing sub-test to a separate helper Sean Christopherson
2019-10-08 4:46 ` [PATCH for_v23 13/16] selftests/x86/sgx: Add a test of the vDSO exception reporting mechanism Sean Christopherson
2019-10-08 4:46 ` [PATCH for_v23 14/16] selftests/x86/sgx: Add test of vDSO with basic exit handler Sean Christopherson
2019-10-08 4:46 ` [PATCH for_v23 15/16] selftests/x86/sgx: Add sub-test for exception behavior with " Sean Christopherson
2019-10-08 4:46 ` [PATCH for_v23 16/16] x86/vdso: sgx: Rework __vdso_sgx_enter_enclave() to prefer "no callback" Sean Christopherson
2019-10-09 18:00 ` Xing, Cedric
2019-10-09 19:10 ` Sean Christopherson
2019-10-10 0:21 ` Sean Christopherson
2019-10-10 17:49 ` Xing, Cedric
2019-10-10 23:59 ` Sean Christopherson
2019-10-16 22:18 ` Xing, Cedric
2019-10-16 22:53 ` Sean Christopherson
2019-10-10 8:10 ` [PATCH for_v23 00/16] x86/vdso: sgx: Major vDSO cleanup Jarkko Sakkinen
2019-10-10 16:08 ` Sean Christopherson
2019-10-14 21:04 ` Jarkko Sakkinen
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