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Improve system call wrappers

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This change improves copy_file_range(), sendfile(), splice(), openpty(),
closefrom(), close_range(), fadvise() and posix_fadvise() in addition to
writing tests that confirm things like errno and seeking behavior across
platforms. We now less aggressively polyfill behavior with some of these
functions when the platform support isn't available. Please see:

https://justine.lol/cosmopolitan/functions.html
This commit is contained in:
Justine Tunney 2022-09-19 15:01:48 -07:00
parent 224c12f54d
commit c7a8cd21e9
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GPG key ID: BE714B4575D6E328
89 changed files with 1151 additions and 414 deletions
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26
libc/calls/closefrom.c
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@ -17,9 +17,10 @@
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/calls/calls.h"
#include "libc/intrin/strace.internal.h"
#include "libc/calls/syscall-sysv.internal.h"
#include "libc/dce.h"
#include "libc/errno.h"
#include "libc/intrin/strace.internal.h"
#include "libc/limits.h"
#include "libc/sysv/errfuns.h"
@ -34,26 +35,27 @@
* }
*
* @return 0 on success, or -1 w/ errno
* @error ENOSYS if not Linux 5.9+ / FreeBSD / OpenBSD
* @error EBADF if `first` is negative
* @error EBADF on OpenBSD if `first` is greater than highest fd
* @error EINVAL if flags are bad or first is greater than last
* @error EMFILE if a weird race condition happens on Linux
* @error ENOSYS if not Linux 5.9+, FreeBSD 8+, or OpenBSD
* @error EINTR possibly on OpenBSD
* @error ENOMEM on Linux maybe
* @note supported on Linux 5.9+, FreeBSD 8+, and OpenBSD
*/
int closefrom(int first) {
int rc, err;
if (first >= 0) {
err = errno;
if ((rc = sys_close_range(first, -1, 0)) == -1) {
if (errno == ENOSYS) {
errno = err;
rc = sys_closefrom(first);
}
}
} else {
if (IsNetbsd() || IsWindows() || IsMetal()) {
rc = enosys();
} else if (first < 0) {
// consistent with openbsd
// freebsd allows this but it's dangerous
// necessary on linux due to type signature
rc = ebadf();
} else if (IsLinux()) {
rc = sys_close_range(first, 0xffffffffu, 0);
} else {
rc = sys_closefrom(first);
}
STRACE("closefrom(%d) → %d% m", first, rc);
return rc;