libfuzzer_amd64.s

     1  // Copyright 2019 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  //go:build libfuzzer
     6  
     7  #include "go_asm.h"
     8  #include "go_tls.h"
     9  #include "textflag.h"
    10  
    11  // Based on race_amd64.s; see commentary there.
    12  
    13  #ifdef GOOS_windows
    14  #define RARG0 CX
    15  #define RARG1 DX
    16  #else
    17  #define RARG0 DI
    18  #define RARG1 SI
    19  #endif
    20  
    21  // void runtime·libfuzzerCall(fn, arg0, arg1 uintptr)
    22  // Calls C function fn from libFuzzer and passes 2 arguments to it.
    23  TEXT	runtime·libfuzzerCall(SB), NOSPLIT, $0-24
    24  	MOVQ	fn+0(FP), AX
    25  	MOVQ	arg0+8(FP), RARG0
    26  	MOVQ	arg1+16(FP), RARG1
    27  
    28  	get_tls(R12)
    29  	MOVQ	g(R12), R14
    30  	MOVQ	g_m(R14), R13
    31  
    32  	// Switch to g0 stack.
    33  	MOVQ	SP, R12		// callee-saved, preserved across the CALL
    34  	MOVQ	m_g0(R13), R10
    35  	CMPQ	R10, R14
    36  	JE	call	// already on g0
    37  	MOVQ	(g_sched+gobuf_sp)(R10), SP
    38  call:
    39  	ANDQ	$~15, SP	// alignment for gcc ABI
    40  	CALL	AX
    41  	MOVQ	R12, SP
    42  	RET
    43
View as plain text