passt/arch.c

51 lines
1.1 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/* PASST - Plug A Simple Socket Transport
* for qemu/UNIX domain socket mode
*
* PASTA - Pack A Subtle Tap Abstraction
* for network namespace/tap device mode
*
* arch.c - Architecture-specific implementations
*
* Copyright (c) 2022 Red Hat GmbH
* Author: Stefano Brivio <sbrivio@redhat.com>
*/
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
/**
* arch_avx2_exec() - Switch to AVX2 build if supported
* @argv: Arguments from command line
*/
#ifdef __x86_64__
void arch_avx2_exec(char **argv)
{
char exe[PATH_MAX] = { 0 };
const char *p;
if (readlink("/proc/self/exe", exe, PATH_MAX - 1) < 0) {
perror("readlink /proc/self/exe");
exit(EXIT_FAILURE);
}
p = strstr(exe, ".avx2");
if (p && strlen(p) == strlen(".avx2"))
return;
if (__builtin_cpu_supports("avx2")) {
char new_path[PATH_MAX + sizeof(".avx2")];
snprintf(new_path, PATH_MAX + sizeof(".avx2"), "%s.avx2", exe);
execve(new_path, argv, environ);
perror("Can't run AVX2 build, using non-AVX2 version");
}
}
#else
void arch_avx2_exec(char **argv) { (void)argv; }
#endif