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// 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.
.syntax unified
.thumb
#include <AsmOffsets.inc> // generated by the build from AsmOffsets.cpp
#include <unixasmmacros.inc>
#define STACKSIZEOF_ExInfo ((SIZEOF__ExInfo + 7)&(~7))
#define rsp_offsetof_ExInfo 0
#define rsp_offsetof_Context STACKSIZEOF_ExInfo
//////////////////////////////////////////////////////////////////////////////////////////////////////////////
//
// RhpThrowHwEx
//
// INPUT: R0: exception code of fault
// R1: faulting RIP
//
// OUTPUT:
//
//////////////////////////////////////////////////////////////////////////////////////////////////////////////
NESTED_ENTRY RhpThrowHwEx, _TEXT, NoHandler
mov r2, r0 // save exception code into r2
mov r0, sp // get SP of fault site
mov lr, r1 // set IP of fault site
// Setup a PAL_LIMITED_CONTEXT on the stack {
PROLOG_VPUSH {d8-d15}
PROLOG_PUSH "{r0,lr}" // push {sp, pc} of fault site
PROLOG_PUSH "{r0,r4-r11,lr}"
// } end PAL_LIMITED_CONTEXT
PROLOG_STACK_ALLOC STACKSIZEOF_ExInfo
// r0: SP of fault site
// r1: IP of fault site
// r2: exception code of fault
// lr: IP of fault site (as a 'return address')
mov r4, r2 // save exception code of fault
// r0 = GetThread()
INLINE_GETTHREAD
// r1 <- ExInfo*
add r1, sp, #rsp_offsetof_ExInfo
mov r3, #0
str r3, [r1, #OFFSETOF__ExInfo__m_exception] // pExInfo->m_exception = null
mov r3, #1
strb r3, [r1, #OFFSETOF__ExInfo__m_passNumber] // pExInfo->m_passNumber = 1
mov r3, #0xFFFFFFFF
str r3, [r1, #OFFSETOF__ExInfo__m_idxCurClause] // pExInfo->m_idxCurClause = MaxTryRegionIdx
mov r3, #2
strb r3, [r1, #OFFSETOF__ExInfo__m_kind] // pExInfo->m_kind = ExKind.HardwareFault
// link the ExInfo into the thread's ExInfo chain
ldr r3, [r0, #OFFSETOF__Thread__m_pExInfoStackHead]
str r3, [r1, #OFFSETOF__ExInfo__m_pPrevExInfo] // pExInfo->m_pPrevExInfo = m_pExInfoStackHead
str r1, [r0, #OFFSETOF__Thread__m_pExInfoStackHead] // m_pExInfoStackHead = pExInfo
mov r0, r4 // restore the exception code
// r0 contains the exception code
// r1 contains the address of the ExInfo
bl C_FUNC(RhThrowHwEx)
EXPORT_POINTER_TO_ADDRESS PointerToRhpThrowHwEx2
// no return
EMIT_BREAKPOINT
NESTED_END RhpThrowHwEx
//////////////////////////////////////////////////////////////////////////////////////////////////////////////
//
// RhpThrowEx
//
// INPUT: R0: exception object
//
// OUTPUT:
//
//////////////////////////////////////////////////////////////////////////////////////////////////////////////
NESTED_ENTRY RhpThrowEx, _TEXT, NoHandler
// Setup a PAL_LIMITED_CONTEXT on the stack {
PROLOG_VPUSH {d8-d15}
PROLOG_PUSH "{r0,lr}" // Reserve space for SP and store LR
PROLOG_PUSH "{r0,r4-r11,lr}"
// } end PAL_LIMITED_CONTEXT
PROLOG_STACK_ALLOC STACKSIZEOF_ExInfo
mov r4, r0 // Save exception object
// r0 = GetThread()
INLINE_GETTHREAD
add r2, sp, #(rsp_offsetof_Context + SIZEOF__PAL_LIMITED_CONTEXT + 0x8) // r2 <- addr of return address
// There is runtime C# code that can tail call to RhpThrowEx using a binder intrinsic. So the return
// address could have been hijacked when we were in that C# code and we must remove the hijack and
// reflect the correct return address in our exception context record. The other throw helpers don't
// need this because they cannot be tail-called from C#.
// NOTE: we cannot use INLINE_THREAD_UNHIJACK because it will write into the stack at the location
// where the tail-calling thread had saved LR, which may not match where we have saved LR.
ldr r1, [r0, #OFFSETOF__Thread__m_pvHijackedReturnAddress]
cbz r1, LOCAL_LABEL(NotHiJacked)
ldr r3, [r0, #OFFSETOF__Thread__m_ppvHijackedReturnAddressLocation]
// r4: exception object
// r1: hijacked return address
// r0: pThread
// r3: hijacked return address location
add r12, sp, #(STACKSIZEOF_ExInfo + SIZEOF__PAL_LIMITED_CONTEXT) // re-compute SP at callsite
cmp r3, r12 // if (m_ppvHijackedReturnAddressLocation < SP at callsite)
blo LOCAL_LABEL(TailCallWasHijacked)
// normal case where a valid return address location is hijacked
str r1, [r3]
b LOCAL_LABEL(ClearThreadState)
LOCAL_LABEL(TailCallWasHijacked):
// Abnormal case where the return address location is now invalid because we ended up here via a tail
// call. In this case, our hijacked return address should be the correct caller of this method.
//
// stick the previous return address in LR as well as in the right spots in our PAL_LIMITED_CONTEXT.
mov lr, r1
str lr, [sp, #(rsp_offsetof_Context + OFFSETOF__PAL_LIMITED_CONTEXT__LR)]
str lr, [sp, #(rsp_offsetof_Context + OFFSETOF__PAL_LIMITED_CONTEXT__IP)]
LOCAL_LABEL(ClearThreadState):
// clear the Thread's hijack state
mov r3, #0
str r3, [r0, #OFFSETOF__Thread__m_ppvHijackedReturnAddressLocation]
str r3, [r0, #OFFSETOF__Thread__m_pvHijackedReturnAddress]
LOCAL_LABEL(NotHiJacked):
add r1, sp, #rsp_offsetof_ExInfo // r1 <- ExInfo*
mov r3, #0
str r3, [r1, #OFFSETOF__ExInfo__m_exception] // init the exception object to null
mov r3, #1
strb r3, [r1, #OFFSETOF__ExInfo__m_passNumber] // init to the first pass
strb r3, [r1, #OFFSETOF__ExInfo__m_kind]
mov r3, #0xFFFFFFFF
str r3, [r1, #OFFSETOF__ExInfo__m_idxCurClause] // ExKind.Throw
// link the ExInfo into the thread's ExInfo chain
ldr r3, [r0, #OFFSETOF__Thread__m_pExInfoStackHead]
str r3, [r1, #OFFSETOF__ExInfo__m_pPrevExInfo] // pExInfo->m_pPrevExInfo = m_pExInfoStackHead
str r1, [r0, #OFFSETOF__Thread__m_pExInfoStackHead] // m_pExInfoStackHead = pExInfo
// set the exception context field on the ExInfo
add r3, sp, #rsp_offsetof_Context // r3 <- PAL_LIMITED_CONTEXT*
str r3, [r1, #OFFSETOF__ExInfo__m_pExContext] // init ExInfo.m_pExContext
mov r0, r4 // Restore exception object
// r0 contains the exception object
// r1 contains the address of the new ExInfo
bl C_FUNC(RhThrowEx)
EXPORT_POINTER_TO_ADDRESS PointerToRhpThrowEx2
// no return
EMIT_BREAKPOINT
NESTED_END RhpThrowEx, _TEXT
//////////////////////////////////////////////////////////////////////////////////////////////////////////////
//
// void FASTCALL RhpRethrow()
//
// SUMMARY: Similar to RhpThrowEx, except that it passes along the currently active ExInfo
//
// INPUT:
//
// OUTPUT:
//
//////////////////////////////////////////////////////////////////////////////////////////////////////////////
NESTED_ENTRY RhpRethrow, _TEXT, NoHandler
// Setup a PAL_LIMITED_CONTEXT on the stack {
PROLOG_VPUSH {d8-d15}
PROLOG_PUSH "{r0,lr}" // Reserve space for SP and store LR
PROLOG_PUSH "{r0,r4-r11,lr}"
// } end PAL_LIMITED_CONTEXT
PROLOG_STACK_ALLOC STACKSIZEOF_ExInfo
// r0 = GetThread();
INLINE_GETTHREAD
// r1 <- ExInfo*
add r1, sp, #rsp_offsetof_ExInfo
mov r3, #0
str r3, [r1, #OFFSETOF__ExInfo__m_exception] // init the exception object to null
strb r3, [r1, #OFFSETOF__ExInfo__m_kind] // init to a deterministic value (ExKind.None)
mov r3, #0xFFFFFFFF
str r3, [r1, #OFFSETOF__ExInfo__m_idxCurClause]
// link the ExInfo into the thread's ExInfo chain
ldr r3, [r0, #OFFSETOF__Thread__m_pExInfoStackHead] // r3 <- currently active ExInfo
str r3, [r1, #OFFSETOF__ExInfo__m_pPrevExInfo] // pExInfo->m_pPrevExInfo = m_pExInfoStackHead
str r1, [r0, #OFFSETOF__Thread__m_pExInfoStackHead] // m_pExInfoStackHead = pExInfo
// set the exception context field on the ExInfo
add r2, sp, #rsp_offsetof_Context // r2 <- PAL_LIMITED_CONTEXT*
str r2, [r1, #OFFSETOF__ExInfo__m_pExContext] // init ExInfo.m_pExContext
mov r0, r3
// r0 contains the currently active ExInfo
// r1 contains the address of the new ExInfo
blx C_FUNC(RhRethrow)
EXPORT_POINTER_TO_ADDRESS PointerToRhpRethrow2
// no return
EMIT_BREAKPOINT
NESTED_END RhpRethrow, _TEXT
//////////////////////////////////////////////////////////////////////////////////////////////////////////////
//
// void* FASTCALL RhpCallCatchFunclet(RtuObjectRef exceptionObj,
// void* pHandlerIP,
// REGDISPLAY* pRegDisplay,
// ExInfo* pExInfo)
//
// INPUT: R0: exception object
// R1: handler funclet address
// R2: REGDISPLAY*
// R3: ExInfo*
//
// OUTPUT:
//
//////////////////////////////////////////////////////////////////////////////////////////////////////////////
NESTED_ENTRY RhpCallCatchFunclet, _TEXT, NoHandler
PROLOG_PUSH "{r0,r2-r11,lr}" // r0, r2 & r3 are saved so we have the exception object,
// REGDISPLAY and ExInfo later
PROLOG_VPUSH {d8-d15}
#define rsp_offset_r2 (8 * 8) + 4
#define rsp_offset_r3 (8 * 8) + 8
mov r4, r0 // Save exception object
mov r5, r1 // Save handler funclet address
mov r6, r2 // Save REGDISPLAY*
// Clear the DoNotTriggerGc state before calling out to our managed catch funclet,
// trashes r0-r2.
// r0 = GetThread()
INLINE_GETTHREAD
LOCAL_LABEL(ClearRetry_Catch):
ldrex r1, [r0, #OFFSETOF__Thread__m_ThreadStateFlags]
bics r1, #TSF_DoNotTriggerGc
strex r2, r1, [r0, #OFFSETOF__Thread__m_ThreadStateFlags]
cbz r2, LOCAL_LABEL(ClearSuccess_Catch)
b LOCAL_LABEL(ClearRetry_Catch)
LOCAL_LABEL(ClearSuccess_Catch):
mov r1, r4 // Reload exception object
mov r3, r5 // Reload handler funclet address
mov r2, r6 // Reload REGDISPLAY pointer
//
// set preserved regs to the values expected by the funclet
//
ldr r12, [r2, #OFFSETOF__REGDISPLAY__pR4]
ldr r4, [r12]
ldr r12, [r2, #OFFSETOF__REGDISPLAY__pR5]
ldr r5, [r12]
ldr r12, [r2, #OFFSETOF__REGDISPLAY__pR6]
ldr r6, [r12]
ldr r12, [r2, #OFFSETOF__REGDISPLAY__pR7]
ldr r7, [r12]
ldr r12, [r2, #OFFSETOF__REGDISPLAY__pR8]
ldr r8, [r12]
ldr r12, [r2, #OFFSETOF__REGDISPLAY__pR9]
ldr r9, [r12]
ldr r12, [r2, #OFFSETOF__REGDISPLAY__pR10]
ldr r10, [r12]
ldr r12, [r2, #OFFSETOF__REGDISPLAY__pR11]
ldr r11, [r12]
//
// load vfp preserved regs
//
add r12, r2, #OFFSETOF__REGDISPLAY__D
vldm r12!, {d8-d15}
ldr r0, [r2, #OFFSETOF__REGDISPLAY__SP] // r0 <- establisher frame
// r1 <- exception object
blx r3 // call handler funclet
mov r4, r0 // Save the result
EXPORT_POINTER_TO_ADDRESS PointerToRhpCallCatchFunclet2
INLINE_GETTHREAD // r0 <- Thread*
// We must unhijack the thread at this point because the section of stack where the
// hijack is applied may go dead. If it does, then the next time we try to unhijack
// the thread, it will corrupt the stack.
INLINE_THREAD_UNHIJACK r0, r3, r12 // Thread in r0, trashes r3 and r1
ldr r2, [sp, #rsp_offset_r2] // r2 <- REGDISPLAY*
ldr r3, [sp, #rsp_offset_r3] // r3 <- current ExInfo*
ldr r2, [r2, #OFFSETOF__REGDISPLAY__SP] // r2 <- resume SP value
LOCAL_LABEL(PopExInfoLoop):
ldr r3, [r3, #OFFSETOF__ExInfo__m_pPrevExInfo] // r3 <- next ExInfo
cbz r3, LOCAL_LABEL(DonePopping) // if (pExInfo == null) { we're done }
cmp r3, r2
blt LOCAL_LABEL(PopExInfoLoop) // if (pExInfo < resume SP} { keep going }
LOCAL_LABEL(DonePopping):
str r3, [r0, #OFFSETOF__Thread__m_pExInfoStackHead] // store the new head on the Thread
// reset RSP and jump to the continuation address
mov sp, r2
bx r4
NESTED_END RhpCallCatchFunclet, _TEXT
//////////////////////////////////////////////////////////////////////////////////////////////////////////////
//
// void FASTCALL RhpCallFinallyFunclet(void* pHandlerIP, REGDISPLAY* pRegDisplay)
//
// INPUT: R0: handler funclet address
// R1: REGDISPLAY*
//
// OUTPUT:
//
//////////////////////////////////////////////////////////////////////////////////////////////////////////////
NESTED_ENTRY RhpCallFinallyFunclet, _TEXT, NoHandler
PROLOG_PUSH "{r1,r4-r11,lr}" // r1 is saved so we have the REGDISPLAY later
PROLOG_VPUSH {d8-d15}
#define rsp_offset_r1 8 * 8
//
// We want to suppress hijacking between invocations of subsequent finallys. We do
// this because we cannot tolerate a GC after one finally has run (and possibly
// side-effected the GC state of the method) and then been popped off the stack,
// leaving behind no trace of its effect.
//
// So we clear the state before and set it after invocation of the handler.
//
mov r4, r0 // Save handler funclet address
mov r5, r1 // Save REGDISPLAY*
//
// clear the DoNotTriggerGc flag, trashes r0-r2
//
INLINE_GETTHREAD // r0 <- Thread*
LOCAL_LABEL(ClearRetry):
ldrex r1, [r0, #OFFSETOF__Thread__m_ThreadStateFlags]
bics r1, #TSF_DoNotTriggerGc
strex r2, r1, [r0, #OFFSETOF__Thread__m_ThreadStateFlags]
cbz r2, LOCAL_LABEL(ClearSuccess)
b LOCAL_LABEL(ClearRetry)
LOCAL_LABEL(ClearSuccess):
mov r2, r4 // reload handler funclet address
mov r1, r5 // reload REGDISPLAY pointer
//
// set preserved regs to the values expected by the funclet
//
ldr r12, [r1, #OFFSETOF__REGDISPLAY__pR4]
ldr r4, [r12]
ldr r12, [r1, #OFFSETOF__REGDISPLAY__pR5]
ldr r5, [r12]
ldr r12, [r1, #OFFSETOF__REGDISPLAY__pR6]
ldr r6, [r12]
ldr r12, [r1, #OFFSETOF__REGDISPLAY__pR7]
ldr r7, [r12]
ldr r12, [r1, #OFFSETOF__REGDISPLAY__pR8]
ldr r8, [r12]
ldr r12, [r1, #OFFSETOF__REGDISPLAY__pR9]
ldr r9, [r12]
ldr r12, [r1, #OFFSETOF__REGDISPLAY__pR10]
ldr r10, [r12]
ldr r12, [r1, #OFFSETOF__REGDISPLAY__pR11]
ldr r11, [r12]
//
// load vfp preserved regs
//
add r12, r1, #OFFSETOF__REGDISPLAY__D
vldm r12!, {d8-d15}
ldr r0, [r1, #OFFSETOF__REGDISPLAY__SP] // r0 <- establisher frame
blx r2 // handler funclet address
EXPORT_POINTER_TO_ADDRESS PointerToRhpCallFinallyFunclet2
ldr r1, [sp, #rsp_offset_r1] // reload REGDISPLAY pointer
//
// save new values of preserved regs into REGDISPLAY
//
ldr r12, [r1, #OFFSETOF__REGDISPLAY__pR4]
str r4, [r12]
ldr r12, [r1, #OFFSETOF__REGDISPLAY__pR5]
str r5, [r12]
ldr r12, [r1, #OFFSETOF__REGDISPLAY__pR6]
str r6, [r12]
ldr r12, [r1, #OFFSETOF__REGDISPLAY__pR7]
str r7, [r12]
ldr r12, [r1, #OFFSETOF__REGDISPLAY__pR8]
str r8, [r12]
ldr r12, [r1, #OFFSETOF__REGDISPLAY__pR9]
str r9, [r12]
ldr r12, [r1, #OFFSETOF__REGDISPLAY__pR10]
str r10, [r12]
ldr r12, [r1, #OFFSETOF__REGDISPLAY__pR11]
str r11, [r12]
//
// store vfp preserved regs
//
add r12, r1, #OFFSETOF__REGDISPLAY__D
vstm r12!, {d8-d15}
//
// set the DoNotTriggerGc flag, trashes r0-r2
//
INLINE_GETTHREAD // r0 <- Thread*
LOCAL_LABEL(SetRetry):
ldrex r1, [r0, #OFFSETOF__Thread__m_ThreadStateFlags]
orrs r1, #TSF_DoNotTriggerGc
strex r2, r1, [r0, #OFFSETOF__Thread__m_ThreadStateFlags]
cbz r2, LOCAL_LABEL(SetSuccess)
b LOCAL_LABEL(SetRetry)
LOCAL_LABEL(SetSuccess):
EPILOG_VPOP {d8-d15}
EPILOG_POP "{r1,r4-r11,pc}"
NESTED_END RhpCallFinallyFunclet, _TEXT
//////////////////////////////////////////////////////////////////////////////////////////////////////////////
//
// void* FASTCALL RhpCallFilterFunclet(RtuObjectRef exceptionObj, void* pFilterIP, REGDISPLAY* pRegDisplay)
//
// INPUT: R0: exception object
// R1: filter funclet address
// R2: REGDISPLAY*
//
// OUTPUT:
//
//////////////////////////////////////////////////////////////////////////////////////////////////////////////
NESTED_ENTRY RhpCallFilterFunclet, _TEXT, NoHandler
PROLOG_PUSH "{r4-r11,lr}"
PROLOG_VPUSH {d8-d15}
ldr r12, [r2, #OFFSETOF__REGDISPLAY__pR7]
ldr r7, [r12]
mov r12, r1 // r12 <- handler funclet address
mov r1, r0 // r1 <- exception object
ldr r0, [r2, #OFFSETOF__REGDISPLAY__SP] // r0 <- establisher frame
//
// call the funclet
// r0 = establisher frame
// r1 = exception object
blx r12
EXPORT_POINTER_TO_ADDRESS PointerToRhpCallFilterFunclet2
// R0 contains the result of the filter execution
EPILOG_VPOP {d8-d15}
EPILOG_POP "{r4-r11,pc}"
NESTED_END RhpCallFilterFunclet, _TEXT
|