base/sys/linux/
descriptor.rs

1// Copyright 2020 The ChromiumOS Authors
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5use crate::descriptor::SafeDescriptor;
6
7const KCMP_FILE: u32 = 0;
8
9impl PartialEq for SafeDescriptor {
10    fn eq(&self, other: &Self) -> bool {
11        // If RawFd numbers match then we can return early without calling kcmp
12        if self.descriptor == other.descriptor {
13            return true;
14        }
15
16        // SAFETY:
17        // safe because we only use the return value and libc says it's always successful
18        let pid = unsafe { libc::getpid() };
19        // SAFETY:
20        // safe because we are passing everything by value and checking the return value
21        let ret = unsafe {
22            libc::syscall(
23                libc::SYS_kcmp,
24                pid,
25                pid,
26                KCMP_FILE,
27                self.descriptor,
28                other.descriptor,
29            )
30        };
31
32        ret == 0
33    }
34}
base/sys/linux/descriptor.rs

base/sys/linux/
descriptor.rs
