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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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36
libc/calls/close_range.c
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@ -17,10 +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/errno.h"
#include "libc/limits.h"
#include "libc/dce.h"
#include "libc/intrin/strace.internal.h"
#include "libc/sysv/errfuns.h"
/**
* Closes inclusive range of file descriptors, e.g.
@ -32,33 +32,27 @@
* }
* }
*
* This is supported on Linux 5.9+, FreeBSD, and OpenBSD. On FreeBSD,
* `flags` must be zero. On OpenBSD, we call closefrom(int) so `last`
* should be `-1` in order to get OpenBSD support, otherwise `ENOSYS`
* will be returned. We also polyfill closefrom on FreeBSD since it's
* available on older kernels.
* The following flags are available:
*
* On Linux, the following flags are supported:
* - `CLOSE_RANGE_UNSHARE` (Linux-only)
* - `CLOSE_RANGE_CLOEXEC` (Linux-only)
*
* - CLOSE_RANGE_UNSHARE
* - CLOSE_RANGE_CLOEXEC
* This is only supported on Linux 5.9+ and FreeBSD 13+. Consider using
* closefrom() which will work on OpenBSD too.
*
* @return 0 on success, or -1 w/ errno
* @error ENOSYS if not Linux 5.9+ / FreeBSD / OpenBSD
* @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 EINTR possibly on OpenBSD
* @error ENOSYS if not Linux 5.9+ or FreeBSD 13+
* @error ENOMEM on Linux maybe
* @see closefrom()
*/
int close_range(unsigned int first, unsigned int last, unsigned int flags) {
int rc, err;
err = errno;
if ((rc = sys_close_range(first, last, flags)) == -1) {
if (errno == ENOSYS && first <= INT_MAX && last == UINT_MAX && !flags) {
errno = err;
rc = sys_closefrom(first);
}
int rc;
if (IsLinux() || IsFreebsd()) {
rc = sys_close_range(first, last, flags);
} else {
rc = enosys();
}
STRACE("close_range(%d, %d, %#x) → %d% m", first, last, flags, rc);
return rc;