diff options
Diffstat (limited to 'src/runtime/sys_windows_arm.s')
| -rw-r--r-- | src/runtime/sys_windows_arm.s | 121 |
1 files changed, 18 insertions, 103 deletions
diff --git a/src/runtime/sys_windows_arm.s b/src/runtime/sys_windows_arm.s index db6d8f1a08..a00fd16670 100644 --- a/src/runtime/sys_windows_arm.s +++ b/src/runtime/sys_windows_arm.s @@ -107,121 +107,36 @@ TEXT runtime·getlasterror(SB),NOSPLIT,$0 RET // Called by Windows as a Vectored Exception Handler (VEH). -// First argument is pointer to struct containing +// R0 is pointer to struct containing // exception record and context pointers. -// Handler function is stored in R1 -// Return 0 for 'not handled', -1 for handled. -// int32_t sigtramp( -// PEXCEPTION_POINTERS ExceptionInfo, -// func *GoExceptionHandler); +// R1 is the kind of sigtramp function. +// Return value of sigtrampgo is stored in R0. TEXT sigtramp<>(SB),NOSPLIT|NOFRAME,$0 - MOVM.DB.W [R0, R4-R11, R14], (R13) // push {r0, r4-r11, lr} (SP-=40) - SUB $(8+20), R13 // reserve space for g, sp, and - // parameters/retval to go call + MOVM.DB.W [R4-R11, R14], (R13) // push {r4-r11, lr} (SP-=40) + SUB $(16), R13 // reserve space for parameters/retval to go call MOVW R0, R6 // Save param0 MOVW R1, R7 // Save param1 - - BL runtime·load_g(SB) - CMP $0, g // is there a current g? - BNE g_ok - ADD $(8+20), R13 // free locals - MOVM.IA.W (R13), [R3, R4-R11, R14] // pop {r3, r4-r11, lr} - MOVW $0, R0 // continue - BEQ return - -g_ok: - - // save g and SP in case of stack switch - MOVW R13, 24(R13) - MOVW g, 20(R13) - - // do we need to switch to the g0 stack? - MOVW g, R5 // R5 = g - MOVW g_m(R5), R2 // R2 = m - MOVW m_g0(R2), R4 // R4 = g0 - CMP R5, R4 // if curg == g0 - BEQ g0 - - // switch to g0 stack - MOVW R4, g // g = g0 - MOVW (g_sched+gobuf_sp)(g), R3 // R3 = g->gobuf.sp - BL runtime·save_g(SB) - - // make room for sighandler arguments - // and re-save old SP for restoring later. - // (note that the 24(R3) here must match the 24(R13) above.) - SUB $40, R3 - MOVW R13, 24(R3) // save old stack pointer - MOVW R3, R13 // switch stack - -g0: - MOVW 0(R6), R2 // R2 = ExceptionPointers->ExceptionRecord - MOVW 4(R6), R3 // R3 = ExceptionPointers->ContextRecord + BL runtime·load_g(SB) // Clobbers R0 MOVW $0, R4 MOVW R4, 0(R13) // No saved link register. - MOVW R2, 4(R13) // Move arg0 (ExceptionRecord) into position - MOVW R3, 8(R13) // Move arg1 (ContextRecord) into position - MOVW R5, 12(R13) // Move arg2 (original g) into position - BL (R7) // Call the goroutine - MOVW 16(R13), R4 // Fetch return value from stack - - // Save system stack pointer for sigresume setup below. - // The exact value does not matter - nothing is read or written - // from this address. It just needs to be on the system stack. - MOVW R13, R12 - - // switch back to original stack and g - MOVW 24(R13), R13 - MOVW 20(R13), g - BL runtime·save_g(SB) - -done: - MOVW R4, R0 // move retval into position - ADD $(8 + 20), R13 // free locals - MOVM.IA.W (R13), [R3, R4-R11, R14] // pop {r3, r4-r11, lr} - - // if return value is CONTINUE_SEARCH, do not set up control - // flow guard workaround - CMP $0, R0 - BEQ return - - // Check if we need to set up the control flow guard workaround. - // On Windows, the stack pointer in the context must lie within - // system stack limits when we resume from exception. - // Store the resume SP and PC on the g0 stack, - // and return to sigresume on the g0 stack. sigresume - // pops the saved PC and SP from the g0 stack, resuming execution - // at the desired location. - // If sigresume has already been set up by a previous exception - // handler, don't clobber the stored SP and PC on the stack. - MOVW 4(R3), R3 // PEXCEPTION_POINTERS->Context - MOVW context_pc(R3), R2 // load PC from context record - MOVW $sigresume<>(SB), R1 - CMP R1, R2 - B.EQ return // do not clobber saved SP/PC - - // Save resume SP and PC into R0, R1. - MOVW context_spr(R3), R2 - MOVW R2, context_r0(R3) - MOVW context_pc(R3), R2 - MOVW R2, context_r1(R3) + MOVW R6, 4(R13) // Move arg0 into position + MOVW R7, 8(R13) // Move arg1 into position + BL runtime·sigtrampgo(SB) + MOVW 12(R13), R0 // Fetch return value from stack - // Set up context record to return to sigresume on g0 stack - MOVW R12, context_spr(R3) - MOVW $sigresume<>(SB), R2 - MOVW R2, context_pc(R3) + ADD $(16), R13 // free locals + MOVM.IA.W (R13), [R4-R11, R14] // pop {r4-r11, lr} -return: B (R14) // return // Trampoline to resume execution from exception handler. // This is part of the control flow guard workaround. // It switches stacks and jumps to the continuation address. -// R0 and R1 are set above at the end of sigtramp<> -// in the context that starts executing at sigresume<>. -TEXT sigresume<>(SB),NOSPLIT|NOFRAME,$0 +// R0 and R1 are set above at the end of sigtrampgo +// in the context that starts executing at sigresume. +TEXT runtime·sigresume(SB),NOSPLIT|NOFRAME,$0 // Important: do not smash LR, // which is set to a live value when handling // a signal by pushing a call to sigpanic onto the stack. @@ -229,15 +144,15 @@ TEXT sigresume<>(SB),NOSPLIT|NOFRAME,$0 B (R1) TEXT runtime·exceptiontramp(SB),NOSPLIT|NOFRAME,$0 - MOVW $runtime·exceptionhandler(SB), R1 + MOVW $const_callbackVEH, R1 B sigtramp<>(SB) TEXT runtime·firstcontinuetramp(SB),NOSPLIT|NOFRAME,$0 - MOVW $runtime·firstcontinuehandler(SB), R1 + MOVW $const_callbackFirstVCH, R1 B sigtramp<>(SB) TEXT runtime·lastcontinuetramp(SB),NOSPLIT|NOFRAME,$0 - MOVW $runtime·lastcontinuehandler(SB), R1 + MOVW $const_callbackLastVCH, R1 B sigtramp<>(SB) GLOBL runtime·cbctxts(SB), NOPTR, $4 |