cosmopolitan/libc/calls/linkat.c
Justine Tunney e522aa3a07
Make more threading improvements
- ASAN memory morgue is now lockless
- Make C11 atomics header more portable
- Rewrote pthread keys support to be lockless
- Simplify Python's unicode table unpacking code
- Make crash report write(2) closer to being atomic
- Make it possible to strace/ftrace a single thread
- ASAN now checks nul-terminated strings fast and properly
- Windows fork() now restores TLS memory of calling thread
2022-11-01 23:28:26 -07:00

58 lines
3.2 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 2021 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/calls/calls.h"
#include "libc/calls/syscall-nt.internal.h"
#include "libc/calls/syscall-sysv.internal.h"
#include "libc/dce.h"
#include "libc/intrin/asan.internal.h"
#include "libc/intrin/describeflags.internal.h"
#include "libc/intrin/strace.internal.h"
#include "libc/intrin/weaken.h"
#include "libc/sysv/errfuns.h"
#include "libc/zipos/zipos.internal.h"
/**
* Creates hard filesystem link.
*
* This allows two names to point to the same file data on disk. They
* can only be differentiated by examining the inode number.
*
* @param flags can have AT_EMPTY_PATH or AT_SYMLINK_NOFOLLOW
* @return 0 on success, or -1 w/ errno
* @asyncsignalsafe
*/
int linkat(int olddirfd, const char *oldpath, int newdirfd, const char *newpath,
int flags) {
int rc;
if (IsAsan() &&
(!__asan_is_valid_str(oldpath) || !__asan_is_valid_str(newpath))) {
rc = efault();
} else if (_weaken(__zipos_notat) &&
((rc = __zipos_notat(olddirfd, oldpath)) == -1 ||
(rc = __zipos_notat(newdirfd, newpath)) == -1)) {
STRACE("zipos fchownat not supported yet");
} else if (!IsWindows()) {
rc = sys_linkat(olddirfd, oldpath, newdirfd, newpath, flags);
} else {
rc = sys_linkat_nt(olddirfd, oldpath, newdirfd, newpath);
}
STRACE("linkat(%s, %#s, %s, %#s, %#b) → %d% m", DescribeDirfd(olddirfd),
oldpath, DescribeDirfd(newdirfd), newpath, flags, rc);
return rc;
}