github.com/go-asm/go@v1.21.1-0.20240213172139-40c5ead50c48/syscall/unix/fallocate_freebsd_arm.go (about)

     1  // Copyright 2023 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package unix
     6  
     7  import "syscall"
     8  
     9  func PosixFallocate(fd int, off int64, size int64) error {
    10  	// If successful, posix_fallocate() returns zero. It returns an error on failure, without
    11  	// setting errno. See https://man.freebsd.org/cgi/man.cgi?query=posix_fallocate&sektion=2&n=1
    12  	//
    13  	// The padding 0 argument is needed because the ARM calling convention requires that if an
    14  	// argument (off in this case) needs double-word alignment (8-byte), the NCRN (next core
    15  	// register number) is rounded up to the next even register number.
    16  	// See https://github.com/ARM-software/abi-aa/blob/2bcab1e3b22d55170c563c3c7940134089176746/aapcs32/aapcs32.rst#parameter-passing
    17  	r1, _, _ := syscall.Syscall6(posixFallocateTrap, uintptr(fd), 0, uintptr(off), uintptr(off>>32), uintptr(size), uintptr(size>>32))
    18  	if r1 != 0 {
    19  		return syscall.Errno(r1)
    20  	}
    21  	return nil
    22  }