--- a/vendor/golang.org/x/sys/unix/syscall_linux.go	Thu Sep 22 16:37:07 2022 +0200
+++ b/vendor/golang.org/x/sys/unix/syscall_linux.go	Sat Feb 04 12:58:35 2023 +0100
@@ -1554,6 +1554,7 @@
 				var iova [1]Iovec
 				iova[0].Base = &dummy
 				iova[0].SetLen(1)
+				iov = iova[:]
 			}
 		}
 		msg.Control = &oob[0]
@@ -1972,36 +1973,46 @@
 //sys	preadv2(fd int, iovs []Iovec, offs_l uintptr, offs_h uintptr, flags int) (n int, err error) = SYS_PREADV2
 //sys	pwritev2(fd int, iovs []Iovec, offs_l uintptr, offs_h uintptr, flags int) (n int, err error) = SYS_PWRITEV2
 
-func bytes2iovec(bs [][]byte) []Iovec {
-	iovecs := make([]Iovec, len(bs))
-	for i, b := range bs {
-		iovecs[i].SetLen(len(b))
+// minIovec is the size of the small initial allocation used by
+// Readv, Writev, etc.
+//
+// This small allocation gets stack allocated, which lets the
+// common use case of len(iovs) <= minIovs avoid more expensive
+// heap allocations.
+const minIovec = 8
+
+// appendBytes converts bs to Iovecs and appends them to vecs.
+func appendBytes(vecs []Iovec, bs [][]byte) []Iovec {
+	for _, b := range bs {
+		var v Iovec
+		v.SetLen(len(b))
 		if len(b) > 0 {
-			iovecs[i].Base = &b[0]
+			v.Base = &b[0]
 		} else {
-			iovecs[i].Base = (*byte)(unsafe.Pointer(&_zero))
+			v.Base = (*byte)(unsafe.Pointer(&_zero))
 		}
+		vecs = append(vecs, v)
 	}
-	return iovecs
+	return vecs
 }
 
-// offs2lohi splits offs into its lower and upper unsigned long. On 64-bit
-// systems, hi will always be 0. On 32-bit systems, offs will be split in half.
-// preadv/pwritev chose this calling convention so they don't need to add a
-// padding-register for alignment on ARM.
+// offs2lohi splits offs into its low and high order bits.
 func offs2lohi(offs int64) (lo, hi uintptr) {
-	return uintptr(offs), uintptr(uint64(offs) >> SizeofLong)
+	const longBits = SizeofLong * 8
+	return uintptr(offs), uintptr(uint64(offs) >> longBits)
 }
 
 func Readv(fd int, iovs [][]byte) (n int, err error) {
-	iovecs := bytes2iovec(iovs)
+	iovecs := make([]Iovec, 0, minIovec)
+	iovecs = appendBytes(iovecs, iovs)
 	n, err = readv(fd, iovecs)
 	readvRacedetect(iovecs, n, err)
 	return n, err
 }
 
 func Preadv(fd int, iovs [][]byte, offset int64) (n int, err error) {
-	iovecs := bytes2iovec(iovs)
+	iovecs := make([]Iovec, 0, minIovec)
+	iovecs = appendBytes(iovecs, iovs)
 	lo, hi := offs2lohi(offset)
 	n, err = preadv(fd, iovecs, lo, hi)
 	readvRacedetect(iovecs, n, err)
@@ -2009,7 +2020,8 @@
 }
 
 func Preadv2(fd int, iovs [][]byte, offset int64, flags int) (n int, err error) {
-	iovecs := bytes2iovec(iovs)
+	iovecs := make([]Iovec, 0, minIovec)
+	iovecs = appendBytes(iovecs, iovs)
 	lo, hi := offs2lohi(offset)
 	n, err = preadv2(fd, iovecs, lo, hi, flags)
 	readvRacedetect(iovecs, n, err)
@@ -2036,7 +2048,8 @@
 }
 
 func Writev(fd int, iovs [][]byte) (n int, err error) {
-	iovecs := bytes2iovec(iovs)
+	iovecs := make([]Iovec, 0, minIovec)
+	iovecs = appendBytes(iovecs, iovs)
 	if raceenabled {
 		raceReleaseMerge(unsafe.Pointer(&ioSync))
 	}
@@ -2046,7 +2059,8 @@
 }
 
 func Pwritev(fd int, iovs [][]byte, offset int64) (n int, err error) {
-	iovecs := bytes2iovec(iovs)
+	iovecs := make([]Iovec, 0, minIovec)
+	iovecs = appendBytes(iovecs, iovs)
 	if raceenabled {
 		raceReleaseMerge(unsafe.Pointer(&ioSync))
 	}
@@ -2057,7 +2071,8 @@
 }
 
 func Pwritev2(fd int, iovs [][]byte, offset int64, flags int) (n int, err error) {
-	iovecs := bytes2iovec(iovs)
+	iovecs := make([]Iovec, 0, minIovec)
+	iovecs = appendBytes(iovecs, iovs)
 	if raceenabled {
 		raceReleaseMerge(unsafe.Pointer(&ioSync))
 	}
@@ -2252,7 +2267,7 @@
 	if n == 0 {
 		return nil
 	}
-	return (*[1 << 30]byte)(unsafe.Pointer(uintptr(unsafe.Pointer(&fh.fileHandle.Type)) + 4))[:n:n]
+	return unsafe.Slice((*byte)(unsafe.Pointer(uintptr(unsafe.Pointer(&fh.fileHandle.Type))+4)), n)
 }
 
 // NameToHandleAt wraps the name_to_handle_at system call; it obtains
@@ -2368,6 +2383,16 @@
 	return prev, nil
 }
 
+//sysnb	rtSigprocmask(how int, set *Sigset_t, oldset *Sigset_t, sigsetsize uintptr) (err error) = SYS_RT_SIGPROCMASK
+
+func PthreadSigmask(how int, set, oldset *Sigset_t) error {
+	if oldset != nil {
+		// Explicitly clear in case Sigset_t is larger than _C__NSIG.
+		*oldset = Sigset_t{}
+	}
+	return rtSigprocmask(how, set, oldset, _C__NSIG/8)
+}
+
 /*
  * Unimplemented
  */
@@ -2426,7 +2451,6 @@
 // RestartSyscall
 // RtSigaction
 // RtSigpending
-// RtSigprocmask
 // RtSigqueueinfo
 // RtSigreturn
 // RtSigsuspend