root/src/pkg/runtime/os_linux_386.c

DEFINITIONS

1. runtimeﾂｷlinux_setup_vdso

// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

#include "runtime.h"
#include "defs_GOOS_GOARCH.h"
#include "os_GOOS.h"
#include "../../cmd/ld/textflag.h"

#define AT_NULL         0
#define AT_RANDOM       25
#define AT_SYSINFO      32
extern uint32 runtimeﾂｷ_vdso;

#pragma textflag NOSPLIT
void
runtimeﾂｷlinux_setup_vdso(int32 argc, byte **argv)
{
        byte **envp;
        uint32 *auxv;

        // skip envp to get to ELF auxiliary vector.
        for(envp = &argv[argc+1]; *envp != nil; envp++)
                ;
        envp++;
        
        for(auxv=(uint32*)envp; auxv[0] != AT_NULL; auxv += 2) {
                if(auxv[0] == AT_SYSINFO) {
                        runtimeﾂｷ_vdso = auxv[1];
                        continue;
                }
                if(auxv[0] == AT_RANDOM) {
                        runtimeﾂｷstartup_random_data = (byte*)auxv[1];
                        runtimeﾂｷstartup_random_data_len = 16;
                        continue;
                }
        }
}