valgrind_amd64.s

Documentation: runtime

     1// Copyright 2025 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 valgrind && linux
     6
     7#include "textflag.h"
     8
     9// Instead of using cgo and using the Valgrind macros, we just emit the special client request
    10// assembly ourselves. The client request mechanism is basically the same across all architectures,
    11// with the notable difference being the special preamble that lets Valgrind know we want to do
    12// a client request.
    13//
    14// The form of the VALGRIND_DO_CLIENT_REQUEST macro assembly can be found in the valgrind/valgrind.h
    15// header file [0].
    16//
    17// [0] https://sourceware.org/git/?p=valgrind.git;a=blob;f=include/valgrind.h.in;h=f1710924aa7372e7b7e2abfbf7366a2286e33d2d;hb=HEAD
    18
    19// func valgrindClientRequest(uintptr, uintptr, uintptr, uintptr, uintptr, uintptr) (ret uintptr)
    20TEXT runtime·valgrindClientRequest(SB), NOSPLIT, $0-56
    21	// Load the address of the first of the (contiguous) arguments into AX.
    22	LEAQ args+0(FP), AX
    23
    24	// Zero DX, since some requests may not populate it.
    25	XORL DX, DX
    26
    27	// Emit the special preabmle.
    28	ROLQ $3, DI; ROLQ $13, DI
    29	ROLQ $61, DI; ROLQ $51, DI
    30
    31	// "Execute" the client request.
    32	XCHGQ BX, BX
    33
    34	// Copy the result out of DX.
    35	MOVQ DX, ret+48(FP)
    36
    37	RET
View as plain text