1 /*
2 * Copyright (c) 2024 Google Inc. All rights reserved
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining
5 * a copy of this software and associated documentation files
6 * (the "Software"), to deal in the Software without restriction,
7 * including without limitation the rights to use, copy, modify, merge,
8 * publish, distribute, sublicense, and/or sell copies of the Software,
9 * and to permit persons to whom the Software is furnished to do so,
10 * subject to the following conditions:
11 *
12 * The above copyright notice and this permission notice shall be
13 * included in all copies or substantial portions of the Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
18 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
19 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
20 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
21 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
22 */
23
24 // TODO: replace with `trusty-log` crate once it is `no_std`-compatible
25
26 use alloc::ffi::CString;
27 use alloc::format;
28 use core::ffi::c_uint;
29 use log::{LevelFilter, Log, Metadata, Record};
30
31 use crate::init::lk_init_level;
32 use crate::LK_INIT_HOOK;
33
34 use crate::sys::fflush;
35 use crate::sys::fputs;
36 use crate::sys::lk_stderr;
37 use crate::sys::LK_LOGLEVEL_RUST;
38
39 static TRUSTY_LOGGER: TrustyKernelLogger = TrustyKernelLogger;
40
41 pub struct TrustyKernelLogger;
42
43 impl Log for TrustyKernelLogger {
enabled(&self, _metadata: &Metadata) -> bool44 fn enabled(&self, _metadata: &Metadata) -> bool {
45 true
46 }
47
log(&self, record: &Record)48 fn log(&self, record: &Record) {
49 if self.enabled(record.metadata()) {
50 let cstr = CString::new(format!("{} - {}\n", record.level(), record.args())).unwrap();
51 // Safety:
52 // The pointer returned by `cstr.as_ptr()` is valid because the lifetime of the
53 // `CString` encompasses the lifetime of the unsafe block.
54 // `lk_stderr()` returns a FILE pointer that is valid or null.
55 unsafe { fputs(cstr.as_ptr(), lk_stderr()) };
56 }
57 }
58
flush(&self)59 fn flush(&self) {
60 // Safety:
61 // `lk_stderr()` returns a FILE pointer that is valid or null.
62 unsafe { fflush(lk_stderr()) };
63 }
64 }
65
66 /// Initialize logging for Rust in the kernel
67 ///
68 /// By default, only warnings and errors are logged (even in debug builds).
69 ///
70 /// The log level (`LK_LOGLEVEL_RUST`) is controlled by these make variables:
71 /// - `LOG_LEVEL_KERNEL_RUST` if set,
72 /// - `LOG_LEVEL_KERNEL` if set, and
73 /// - `DEBUG` otherwise.
74 ///
75 /// Values below (above) expected values sets the log level to off (trace).
kernel_log_init_func(_level: c_uint)76 extern "C" fn kernel_log_init_func(_level: c_uint) {
77 log::set_logger(&TRUSTY_LOGGER).unwrap();
78 // Level or LevelFilter cannot be created directly from integers
79 // https://github.com/rust-lang/log/issues/460
80 //
81 // bindgen emits `LK_LOGLEVEL_RUST` as `u32` when the value is
82 // a positive integer and omits it otherwise thus causing the
83 // build to fail.
84 log::set_max_level(match LK_LOGLEVEL_RUST {
85 0 => LevelFilter::Off,
86 1 => LevelFilter::Error,
87 2 => LevelFilter::Warn, // the default for Trusty
88 3 => LevelFilter::Info,
89 4 => LevelFilter::Debug,
90 _ => LevelFilter::Trace, // enable trace! at 5+
91 });
92 }
93
94 LK_INIT_HOOK!(kernel_log_init, kernel_log_init_func, lk_init_level::LK_INIT_LEVEL_HEAP);
95