Implement magiskinit logging in Rust

This commit is contained in:
topjohnwu 2023-05-02 16:49:43 -07:00
parent 0d84f80b3c
commit b136aba1e2
8 changed files with 84 additions and 83 deletions

12
native/src/Cargo.lock generated
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@ -13,9 +13,9 @@ dependencies = [
[[package]]
name = "cc"
version = "1.0.73"
version = "1.0.79"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "2fff2a6927b3bb87f9595d67196a70493f627687a71d87a0d692242c33f58c11"
checksum = "50d30906286121d95be3d479533b458f87493b30a4b5f79a607db8f5d11aa91f"
[[package]]
name = "cfg-if"
@ -47,9 +47,9 @@ dependencies = [
[[package]]
name = "libc"
version = "0.2.127"
version = "0.2.142"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "505e71a4706fa491e9b1b55f51b95d4037d0821ee40131190475f692b35b009b"
checksum = "6a987beff54b60ffa6d51982e1aa1146bc42f19bd26be28b0586f252fccf5317"
[[package]]
name = "magisk"
@ -112,6 +112,6 @@ dependencies = [
[[package]]
name = "unicode-ident"
version = "1.0.2"
version = "1.0.8"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "15c61ba63f9235225a22310255a29b806b907c9b8c964bcbd0a2c70f3f2deea7"
checksum = "e5464a87b239f13a63a501f2701565754bae92d243d4bb7eb12f6d57d2269bf4"

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@ -53,20 +53,20 @@ pub fn __xopen_fd_impl(path: &CStr, flags: i32, mode: mode_t) -> Option<OwnedFd>
#[macro_export]
macro_rules! open_fd {
($path:expr, $flags:expr) => {
crate::__open_fd_impl($path, $flags, 0)
$crate::__open_fd_impl($path, $flags, 0)
};
($path:expr, $flags:expr, $mode:expr) => {
crate::__open_fd_impl($path, $flags, $mode)
$crate::__open_fd_impl($path, $flags, $mode)
};
}
#[macro_export]
macro_rules! xopen_fd {
($path:expr, $flags:expr) => {
crate::__xopen_fd_impl($path, $flags, 0)
$crate::__xopen_fd_impl($path, $flags, 0)
};
($path:expr, $flags:expr, $mode:expr) => {
crate::__xopen_fd_impl($path, $flags, $mode)
$crate::__xopen_fd_impl($path, $flags, $mode)
};
}

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@ -3,6 +3,13 @@ use std::ffi::CStr;
use std::fmt::Arguments;
use std::{fmt, slice};
pub fn copy_str(dest: &mut [u8], src: &[u8]) -> usize {
let len = min(src.len(), dest.len() - 1);
dest[..len].copy_from_slice(&src[..len]);
dest[len] = b'\0';
len
}
struct BufFmtWriter<'a> {
buf: &'a mut [u8],
used: usize,
@ -21,12 +28,7 @@ impl<'a> fmt::Write for BufFmtWriter<'a> {
// Silent truncate
return Ok(());
}
let remain = &mut self.buf[self.used..];
let s_bytes = s.as_bytes();
let copied = min(s_bytes.len(), remain.len() - 1);
remain[..copied].copy_from_slice(&s_bytes[..copied]);
self.used += copied;
self.buf[self.used] = b'\0';
self.used += copy_str(&mut self.buf[self.used..], s.as_bytes());
// Silent truncate
Ok(())
}
@ -107,6 +109,13 @@ macro_rules! cstr {
}};
}
#[macro_export]
macro_rules! str_ptr {
($s:literal) => {{
cstr!($s).as_ptr()
}};
}
pub fn ptr_to_str<'a, T>(ptr: *const T) -> &'a str {
if ptr.is_null() {
"(null)"

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@ -117,55 +117,6 @@ static bool check_key_combo() {
return false;
}
static FILE *kmsg;
extern "C" void klog_write(const char *msg, int len) {
fprintf(kmsg, "%.*s", len, msg);
}
static int klog_with_rs(LogLevel level, const char *fmt, va_list ap) {
char buf[4096];
strscpy(buf, "magiskinit: ", sizeof(buf));
int len = vssprintf(buf + 12, sizeof(buf) - 12, fmt, ap) + 12;
log_with_rs(level, rust::Str(buf, len));
return len;
}
void setup_klog() {
// Shut down first 3 fds
int fd;
if (access("/dev/null", W_OK) == 0) {
fd = xopen("/dev/null", O_RDWR | O_CLOEXEC);
} else {
mknod("/null", S_IFCHR | 0666, makedev(1, 3));
fd = xopen("/null", O_RDWR | O_CLOEXEC);
unlink("/null");
}
xdup3(fd, STDIN_FILENO, O_CLOEXEC);
xdup3(fd, STDOUT_FILENO, O_CLOEXEC);
xdup3(fd, STDERR_FILENO, O_CLOEXEC);
if (fd > STDERR_FILENO)
close(fd);
if (access("/dev/kmsg", W_OK) == 0) {
fd = xopen("/dev/kmsg", O_WRONLY | O_CLOEXEC);
} else {
mknod("/kmsg", S_IFCHR | 0666, makedev(1, 11));
fd = xopen("/kmsg", O_WRONLY | O_CLOEXEC);
unlink("/kmsg");
}
kmsg = fdopen(fd, "w");
setbuf(kmsg, nullptr);
rust::setup_klog();
cpp_logger = klog_with_rs;
// Disable kmsg rate limiting
if (FILE *rate = fopen("/proc/sys/kernel/printk_devkmsg", "w")) {
fprintf(rate, "on\n");
fclose(rate);
}
}
void BootConfig::set(const kv_pairs &kv) {
for (const auto &[key, value] : kv) {
if (key == "androidboot.slot_suffix") {
@ -231,7 +182,7 @@ void load_kernel_info(BootConfig *config) {
mount_list.emplace_back("/sys");
// Log to kernel
setup_klog();
rust::setup_klog();
config->set(parse_cmdline(full_read("/proc/cmdline")));
config->set(parse_bootconfig(full_read("/proc/bootconfig")));

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@ -90,6 +90,7 @@ int main(int argc, char *argv[]) {
BootConfig config{};
if (argc > 1 && argv[1] == "selinux_setup"sv) {
rust::setup_klog();
init = new SecondStageInit(argv);
} else {
// This will also mount /sys and /proc

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@ -28,7 +28,6 @@ int magisk_proxy_main(int argc, char *argv[]);
bool unxz(int fd, const uint8_t *buf, size_t size);
void load_kernel_info(BootConfig *config);
bool check_two_stage();
void setup_klog();
const char *backup_init();
void restore_ramdisk_init();
int dump_preload(const char *path, mode_t mode);
@ -87,7 +86,6 @@ private:
bool prepare();
public:
SecondStageInit(char *argv[]) : MagiskInit(argv) {
setup_klog();
LOGD("%s\n", __FUNCTION__);
};

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@ -1,27 +1,69 @@
use base::ffi::LogLevel;
use base::*;
use std::fmt::Arguments;
use std::fs;
use std::fs::File;
use std::io::Write;
use std::sync::OnceLock;
extern "C" {
fn klog_write(msg: *const u8, len: i32);
}
use base::ffi::LogLevel;
use base::libc::{
close, makedev, mknod, open, syscall, unlink, SYS_dup3, O_CLOEXEC, O_RDWR, STDERR_FILENO,
STDIN_FILENO, STDOUT_FILENO, S_IFCHR,
};
use base::*;
static KMSG: OnceLock<File> = OnceLock::new();
pub fn setup_klog() {
const PREFIX: &[u8; 12] = b"magiskinit: ";
const PFX_LEN: usize = PREFIX.len();
// Shut down first 3 fds
unsafe {
let mut fd = open(str_ptr!("/dev/null"), O_RDWR | O_CLOEXEC);
if fd < 0 {
mknod(str_ptr!("/null"), S_IFCHR | 0666, makedev(1, 3));
fd = open(str_ptr!("/null"), O_RDWR | O_CLOEXEC);
fs::remove_file("/null").ok();
}
syscall(SYS_dup3, fd, STDIN_FILENO, O_CLOEXEC);
syscall(SYS_dup3, fd, STDOUT_FILENO, O_CLOEXEC);
syscall(SYS_dup3, fd, STDERR_FILENO, O_CLOEXEC);
if fd > STDERR_FILENO {
close(fd);
}
}
if let Ok(kmsg) = File::options().write(true).open("/dev/kmsg") {
KMSG.set(kmsg).ok();
} else {
unsafe {
mknod(str_ptr!("/kmsg"), S_IFCHR | 0666, makedev(1, 11));
KMSG.set(File::options().write(true).open("/kmsg").unwrap())
.ok();
unlink(str_ptr!("/kmsg"));
}
}
// Disable kmsg rate limiting
if let Ok(mut rate) = File::options()
.write(true)
.open("/proc/sys/kernel/printk_devkmsg")
{
writeln!(rate, "on").ok();
}
fn klog_fmt(_: LogLevel, args: Arguments) {
let mut buf: [u8; 4096] = [0; 4096];
buf[..PFX_LEN].copy_from_slice(PREFIX);
let len = fmt_to_buf(&mut buf[PFX_LEN..], args) + PFX_LEN;
unsafe {
klog_write(buf.as_ptr(), len as i32);
if let Some(kmsg) = KMSG.get().as_mut() {
let mut buf: [u8; 4096] = [0; 4096];
let len = fmt_to_buf(&mut buf, format_args!("magiskinit: {}", args));
kmsg.write_all(&buf[..len]).ok();
}
}
fn klog_write_impl(_: LogLevel, msg: &[u8]) {
unsafe {
klog_write(msg.as_ptr(), msg.len() as i32);
if let Some(kmsg) = KMSG.get().as_mut() {
let mut buf: [u8; 4096] = [0; 4096];
let mut len = copy_str(&mut buf, b"magiskinit: ");
len += copy_str(&mut buf[len..], msg);
kmsg.write_all(&buf[..len]).ok();
}
}

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@ -349,7 +349,7 @@ void MagiskInit::patch_rw_root() {
}
int magisk_proxy_main(int argc, char *argv[]) {
setup_klog();
rust::setup_klog();
LOGD("%s\n", __FUNCTION__);
// Mount rootfs as rw to do post-init rootfs patches