cosmopolitan/tool/build/lib/elfwriter_yoink.c

34 lines
2.4 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney │
│ │
│ This program is free software; you can redistribute it and/or modify │
│ it under the terms of the GNU General Public License as published by │
│ the Free Software Foundation; version 2 of the License. │
│ │
│ This program is distributed in the hope that it will be useful, but │
│ WITHOUT ANY WARRANTY; without even the implied warranty of │
│ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU │
│ General Public License for more details. │
│ │
│ You should have received a copy of the GNU General Public License │
│ along with this program; if not, write to the Free Software │
│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA │
│ 02110-1301 USA │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/str/str.h"
#include "tool/build/lib/elfwriter.h"
void elfwriter_yoink(struct ElfWriter *elf, const char *symbol) {
unsigned char *p;
struct ElfWriterSymRef sym;
const unsigned char nopl[8] = "\x0f\x1f\x04\x25\x00\x00\x00\x00";
p = elfwriter_reserve(elf, 8);
memcpy(p, nopl, sizeof(nopl));
sym = elfwriter_linksym(elf, symbol, ELF64_ST_INFO(STB_GLOBAL, STT_OBJECT),
STV_HIDDEN);
elfwriter_appendrela(elf, sizeof(nopl) - 4, sym, R_X86_64_32, 0);
elfwriter_commit(elf, sizeof(nopl));
}