cosmopolitan/libc/calls/mprotect.greg.c

55 lines
2.8 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 │
╚─────────────────────────────────────────────────────────────────────────────*/
#define ShouldUseMsabiAttribute() 1
#include "libc/bits/bits.h"
#include "libc/calls/internal.h"
#include "libc/dce.h"
#include "libc/errno.h"
#include "libc/nt/memory.h"
#include "libc/nt/thunk/msabi.h"
#include "libc/sysv/consts/nr.h"
privileged int __mprotect(void *addr, uint64_t len, int prot) {
extern __msabi typeof(VirtualProtect) *const __imp_VirtualProtect;
bool cf;
int64_t rc;
uint32_t oldprot;
if (!IsWindows()) {
asm volatile(CFLAG_ASM("syscall")
: CFLAG_CONSTRAINT(cf), "=a"(rc)
: "1"(__NR_mprotect), "D"(addr), "S"(len), "d"(prot)
: "rcx", "r11", "memory", "cc");
if (cf) {
rc = -rc;
rc = -1;
} else if (rc > -4096ul) {
errno = -rc;
rc = -1;
}
return rc;
} else {
if (__imp_VirtualProtect(addr, len, prot2nt(prot, 0), &oldprot)) {
return 0;
} else {
return winerr();
}
}
}