diff options
Diffstat (limited to 'src/Native/System.Private.TypeLoader.Native/i386/ConstrainedCallSupportHelpers.asm')
| -rw-r--r-- | src/Native/System.Private.TypeLoader.Native/i386/ConstrainedCallSupportHelpers.asm | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/src/Native/System.Private.TypeLoader.Native/i386/ConstrainedCallSupportHelpers.asm b/src/Native/System.Private.TypeLoader.Native/i386/ConstrainedCallSupportHelpers.asm new file mode 100644 index 000000000..8b3298180 --- /dev/null +++ b/src/Native/System.Private.TypeLoader.Native/i386/ConstrainedCallSupportHelpers.asm @@ -0,0 +1,100 @@ +;; Licensed to the .NET Foundation under one or more agreements. +;; The .NET Foundation licenses this file to you under the MIT license. +;; See the LICENSE file in the project root for more information. + +.586 +.model flat +option casemap:none +.code + +;; ----------------------------------------------------------------------------------------------------------- +;; standard macros +;; ----------------------------------------------------------------------------------------------------------- +LEAF_ENTRY macro Name, Section + Section segment para 'CODE' + public Name + Name proc +endm + +LEAF_END macro Name, Section + Name endp + Section ends +endm + + +;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; DATA SECTIONS ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; + +;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ConstrainedCall Support Helpers ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; + + +;; +;; Note: The "__jmpstub__" prefix is used to indicate to debugger +;; that it must step-through this stub when it encounters it while +;; stepping. +;; + +;; +;; __jmpstub__ConstrainedCallSupport_DerefThisAndCall_CommonCallingStub +;; +;; eax - AddressOfAddressOfFunctionToCallAfterDereferencingThis +;; +LEAF_ENTRY __jmpstub__ConstrainedCallSupport_DerefThisAndCall_CommonCallingStub, _TEXT + mov eax, [eax] ; Get function pointer to call + mov ecx, [ecx] ; Deference this to get real this pointer + jmp eax +LEAF_END __jmpstub__ConstrainedCallSupport_DerefThisAndCall_CommonCallingStub, _TEXT + +;; +;; void ConstrainedCallSupport_GetStubs(IntPtr *__jmpstub__ConstrainedCallSupport_DerefThisAndCall_CommonCallingStub, +;; IntPtr *__jmpstub__ConstrainedCallSupport_DirectConstrainedCallCommonStub) +;; +LEAF_ENTRY ConstrainedCallSupport_GetStubs, _TEXT + lea eax, [__jmpstub__ConstrainedCallSupport_DerefThisAndCall_CommonCallingStub] + mov ecx, [esp+04h] + mov [ecx], eax + lea eax, [__jmpstub__ConstrainedCallSupport_DirectConstrainedCallCommonStub] + mov ecx, [esp+08h] + mov [ecx], eax + retn 8h +LEAF_END ConstrainedCallSupport_GetStubs, _TEXT + +;; +;; __jmpstub__ConstrainedCallSupport_DirectConstrainedCallCommonStub +;; +;; struct ConstrainedCallDesc +;; { +;; ULONG_PTR ExactTarget; +;; ULONG_PTR LookupFunc; // Put UniversalThunk here +;; } +;; +;; struct CommonCallingStubInputData +;; { +;; ULONG_PTR ConstrainedCallDesc; +;; ULONG_PTR DirectConstrainedCallResolver; +;; } +;; +;; eax - Points at CommonCallingStubInputData +;; +;; +LEAF_ENTRY __jmpstub__ConstrainedCallSupport_DirectConstrainedCallCommonStub, _TEXT +;; eax points at CommonCallingStubInputData + push eax ; save eax + mov eax,[eax] ; put ConstrainedCallDesc in eax + mov eax,[eax] ; Load ExactTarget into eax + test eax,eax ; Check ExactTarget for null + jz NeedsHelperCall + add esp,4 ; Adjust eax back to what it was before the first instruction push + jmp eax ; TailCall exact target +NeedsHelperCall: + pop eax ; Restore back to exact state that was present at start of function +;; eax points at CommonCallingStubInputData + push ebp + mov ebp, esp + push [eax] ; First argument (ConstrainedCallDesc) + push [eax+4] ; Second argument (DirectConstrainedCallResolver) + mov eax,[eax] ; Load ConstrainedCallDesc into eax + mov eax,[eax+4] ; Load Universal Thunk address into eax + jmp eax +LEAF_END __jmpstub__ConstrainedCallSupport_DirectConstrainedCallCommonStub, _TEXT + +end |