diff options
Diffstat (limited to 'src/runtime/sys_windows_arm.s')
| -rw-r--r-- | src/runtime/sys_windows_arm.s | 208 |
1 files changed, 51 insertions, 157 deletions
diff --git a/src/runtime/sys_windows_arm.s b/src/runtime/sys_windows_arm.s index fe267080cc..9a5d9b1dd4 100644 --- a/src/runtime/sys_windows_arm.s +++ b/src/runtime/sys_windows_arm.s @@ -6,6 +6,8 @@ #include "go_tls.h" #include "textflag.h" +// Note: For system ABI, R0-R3 are args, R4-R11 are callee-save. + // void runtime·asmstdcall(void *c); TEXT runtime·asmstdcall(SB),NOSPLIT|NOFRAME,$0 MOVM.DB.W [R4, R5, R14], (R13) // push {r4, r5, lr} @@ -103,11 +105,6 @@ TEXT runtime·getlasterror(SB),NOSPLIT,$0 MOVW R0, ret+0(FP) RET -TEXT runtime·setlasterror(SB),NOSPLIT|NOFRAME,$0 - MRC 15, 0, R1, C13, C0, 2 - MOVW R0, 0x34(R1) - RET - // Called by Windows as a Vectored Exception Handler (VEH). // First argument is pointer to struct containing // exception record and context pointers. @@ -144,11 +141,10 @@ TEXT sigtramp<>(SB),NOSPLIT|NOFRAME,$0 MOVW (g_sched+gobuf_sp)(g), R3 // R3 = g->gobuf.sp BL runtime·save_g(SB) - // traceback will think that we've done PUSH and SUB - // on this stack, so subtract them here to match. - // (we need room for sighandler arguments anyway). + // make room for sighandler arguments // and re-save old SP for restoring later. - SUB $(40+8+20), R3 + // (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 @@ -156,21 +152,18 @@ g0: MOVW 0(R6), R2 // R2 = ExceptionPointers->ExceptionRecord MOVW 4(R6), R3 // R3 = ExceptionPointers->ContextRecord - // make it look like mstart called us on g0, to stop traceback - MOVW $runtime·mstart(SB), R4 - - MOVW R4, 0(R13) // Save link register for traceback + 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 go routine MOVW 16(R13), R4 // Fetch return value from stack - // Compute the value of the g0 stack pointer after deallocating - // this frame, then allocating 8 bytes. We may need to store - // the resume SP and PC on the g0 stack to work around - // control flow guard when we resume from the exception. - ADD $(40+20), R13, R12 + // 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 @@ -188,42 +181,45 @@ done: BEQ return // Check if we need to set up the control flow guard workaround. - // On Windows/ARM, the stack pointer must lie within system - // stack limits when we resume from exception. + // 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 returntramp on the g0 stack. returntramp + // 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 returntramp has already been set up by a previous exception + // 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 0x40(R3), R2 // load PC from context record - MOVW $returntramp<>(SB), R1 + 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 on g0 stack - MOVW 0x38(R3), R2 // load SP from context record - MOVW R2, 0(R12) // Store resume SP on g0 stack - MOVW 0x40(R3), R2 // load PC from context record - MOVW R2, 4(R12) // Store resume PC on g0 stack + // 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) - // Set up context record to return to returntramp on g0 stack - MOVW R12, 0x38(R3) // save g0 stack pointer - // in context record - MOVW $returntramp<>(SB), R2 // save resume address - MOVW R2, 0x40(R3) // in context record + // 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) 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. -// -TEXT returntramp<>(SB),NOSPLIT|NOFRAME,$0 - MOVM.IA (R13), [R13, R15] // ldm sp, [sp, pc] +// 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 + // 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. + MOVW R0, R13 + B (R1) TEXT runtime·exceptiontramp(SB),NOSPLIT|NOFRAME,$0 MOVW $runtime·exceptionhandler(SB), R1 @@ -259,16 +255,17 @@ TEXT runtime·profileloop(SB),NOSPLIT|NOFRAME,$0 // +----------------+ // 12| argument (r0) | //---+----------------+ -// 8 | param1 | +// 8 | param1 | (also return value for called Go function) // +----------------+ // 4 | param0 | // +----------------+ -// 0 | retval | +// 0 | slot for LR | // +----------------+ // -TEXT runtime·externalthreadhandler(SB),NOSPLIT|NOFRAME,$0 +TEXT runtime·externalthreadhandler(SB),NOSPLIT|NOFRAME|TOPFRAME,$0 MOVM.DB.W [R4-R11, R14], (R13) // push {r4-r11, lr} SUB $(m__size + g__size + 20), R13 // space for locals + MOVW R14, 0(R13) // push LR again for anything unwinding the stack MOVW R0, 12(R13) MOVW R1, 16(R13) @@ -307,7 +304,7 @@ TEXT runtime·externalthreadhandler(SB),NOSPLIT|NOFRAME,$0 MOVW $0, g BL runtime·save_g(SB) - MOVW 0(R13), R0 // load return value + MOVW 8(R13), R0 // load return value ADD $(m__size + g__size + 20), R13 // free locals MOVM.IA.W (R13), [R4-R11, R15] // pop {r4-r11, pc} @@ -359,9 +356,6 @@ TEXT runtime·tstart_stdcall(SB),NOSPLIT|NOFRAME,$0 MOVW R0, g_m(g) BL runtime·save_g(SB) - // do per-thread TLS initialization - BL init_thread_tls<>(SB) - // Layout new m scheduler stack on os stack. MOVW R13, R0 MOVW R0, g_stack+stack_hi(g) @@ -377,84 +371,15 @@ TEXT runtime·tstart_stdcall(SB),NOSPLIT|NOFRAME,$0 MOVW $0, R0 MOVM.IA.W (R13), [R4-R11, R15] // pop {r4-r11, pc} -// onosstack calls fn on OS stack. -// adapted from asm_arm.s : systemstack -// func onosstack(fn unsafe.Pointer, arg uint32) -TEXT runtime·onosstack(SB),NOSPLIT,$0 - MOVW fn+0(FP), R5 // R5 = fn - MOVW arg+4(FP), R6 // R6 = arg - - // This function can be called when there is no g, - // for example, when we are handling a callback on a non-go thread. - // In this case we're already on the system stack. - CMP $0, g - BEQ noswitch - - MOVW g_m(g), R1 // R1 = m - - MOVW m_gsignal(R1), R2 // R2 = gsignal - CMP g, R2 - B.EQ noswitch - - MOVW m_g0(R1), R2 // R2 = g0 - CMP g, R2 - B.EQ noswitch - - MOVW m_curg(R1), R3 - CMP g, R3 - B.EQ switch - - // Bad: g is not gsignal, not g0, not curg. What is it? - // Hide call from linker nosplit analysis. - MOVW $runtime·badsystemstack(SB), R0 - BL (R0) - B runtime·abort(SB) - -switch: - // save our state in g->sched. Pretend to - // be systemstack_switch if the G stack is scanned. - MOVW $runtime·systemstack_switch(SB), R3 - ADD $4, R3, R3 // get past push {lr} - MOVW R3, (g_sched+gobuf_pc)(g) - MOVW R13, (g_sched+gobuf_sp)(g) - MOVW LR, (g_sched+gobuf_lr)(g) - MOVW g, (g_sched+gobuf_g)(g) - - // switch to g0 - MOVW R2, g - MOVW (g_sched+gobuf_sp)(R2), R3 - // make it look like mstart called systemstack on g0, to stop traceback - SUB $4, R3, R3 - MOVW $runtime·mstart(SB), R4 - MOVW R4, 0(R3) - MOVW R3, R13 - - // call target function - MOVW R6, R0 // arg - BL (R5) - - // switch back to g - MOVW g_m(g), R1 - MOVW m_curg(R1), g - MOVW (g_sched+gobuf_sp)(g), R13 - MOVW $0, R3 - MOVW R3, (g_sched+gobuf_sp)(g) - RET - -noswitch: - // Using a tail call here cleans up tracebacks since we won't stop - // at an intermediate systemstack. - MOVW.P 4(R13), R14 // restore LR - MOVW R6, R0 // arg - B (R5) - -// Runs on OS stack. Duration (in 100ns units) is in R0. -TEXT runtime·usleep2(SB),NOSPLIT|NOFRAME,$0 +// Runs on OS stack. +// duration (in -100ns units) is in dt+0(FP). +// g may be nil. +TEXT runtime·usleep2(SB),NOSPLIT|NOFRAME,$0-4 + MOVW dt+0(FP), R3 MOVM.DB.W [R4, R14], (R13) // push {r4, lr} MOVW R13, R4 // Save SP SUB $8, R13 // R13 = R13 - 8 BIC $0x7, R13 // Align SP for ABI - RSB $0, R0, R3 // R3 = -R0 MOVW $0, R1 // R1 = FALSE (alertable) MOVW $-1, R0 // R0 = handle MOVW R13, R2 // R2 = pTime @@ -465,9 +390,11 @@ TEXT runtime·usleep2(SB),NOSPLIT|NOFRAME,$0 MOVW R4, R13 // Restore SP MOVM.IA.W (R13), [R4, R15] // pop {R4, pc} -// Runs on OS stack. Duration (in 100ns units) is in R0. +// Runs on OS stack. +// duration (in -100ns units) is in dt+0(FP). +// g is valid. // TODO: neeeds to be implemented properly. -TEXT runtime·usleep2HighRes(SB),NOSPLIT|NOFRAME,$0 +TEXT runtime·usleep2HighRes(SB),NOSPLIT|NOFRAME,$0-4 B runtime·abort(SB) // Runs on OS stack. @@ -497,7 +424,7 @@ TEXT runtime·read_tls_fallback(SB),NOSPLIT|NOFRAME,$0 #define time_hi1 4 #define time_hi2 8 -TEXT runtime·nanotime1(SB),NOSPLIT,$0-8 +TEXT runtime·nanotime1(SB),NOSPLIT|NOFRAME,$0-8 MOVW $0, R0 MOVB runtime·useQPCTime(SB), R0 CMP $0, R0 @@ -521,9 +448,8 @@ loop: RET useQPC: B runtime·nanotimeQPC(SB) // tail call - RET -TEXT time·now(SB),NOSPLIT,$0-20 +TEXT time·now(SB),NOSPLIT|NOFRAME,$0-20 MOVW $0, R0 MOVB runtime·useQPCTime(SB), R0 CMP $0, R0 @@ -597,8 +523,7 @@ wall: MOVW R1,nsec+8(FP) RET useQPC: - B runtime·nanotimeQPC(SB) // tail call - RET + B runtime·nowQPC(SB) // tail call // save_g saves the g register (R10) into thread local memory // so that we can call externally compiled @@ -656,39 +581,8 @@ TEXT runtime·_initcgo(SB),NOSPLIT|NOFRAME,$0 MOVW $runtime·tls_g(SB), R1 MOVW R0, (R1) - BL init_thread_tls<>(SB) - MOVW R4, R13 MOVM.IA.W (R13), [R4, R15] // pop {r4, pc} -// void init_thread_tls() -// -// Does per-thread TLS initialization. Saves a pointer to the TLS slot -// holding G, in the current m. -// -// g->m->tls[0] = &_TEB->TlsSlots[tls_g] -// -// The purpose of this is to enable the profiling handler to get the -// current g associated with the thread. We cannot use m->curg because curg -// only holds the current user g. If the thread is executing system code or -// external code, m->curg will be NULL. The thread's TLS slot always holds -// the current g, so save a reference to this location so the profiling -// handler can get the real g from the thread's m. -// -// Clobbers R0-R3 -TEXT init_thread_tls<>(SB),NOSPLIT|NOFRAME,$0 - // compute &_TEB->TlsSlots[tls_g] - MRC 15, 0, R0, C13, C0, 2 - ADD $0xe10, R0 - MOVW $runtime·tls_g(SB), R1 - MOVW (R1), R1 - MOVW R1<<2, R1 - ADD R1, R0 - - // save in g->m->tls[0] - MOVW g_m(g), R1 - MOVW R0, m_tls(R1) - RET - // Holds the TLS Slot, which was allocated by TlsAlloc() GLOBL runtime·tls_g+0(SB), NOPTR, $4 |