Improve Rust implementation

- Move mmap_file implementation into Rust
- Introduce Utf8CStr as the better c-string type to use

native/src/base/cxx_extern.rs

@@ -1,14 +1,18 @@
 // Functions listed here are just to export to C++
 
-use crate::{fd_path, mkdirs, realpath, rm_rf, slice_from_ptr_mut, Directory, ResultExt};
+use std::ffi::CStr;
+use std::io;
+use std::os::fd::{BorrowedFd, OwnedFd, RawFd};
+
 use anyhow::Context;
 use cxx::private::c_char;
 use libc::mode_t;
-use std::ffi::CStr;
-use std::io;
-use std::os::fd::{OwnedFd, RawFd};
 
-pub fn fd_path_for_cxx(fd: RawFd, buf: &mut [u8]) -> isize {
+use crate::{
+    fd_path, map_fd, map_file, mkdirs, realpath, rm_rf, slice_from_ptr_mut, Directory, ResultExt,
+};
+
+pub(crate) fn fd_path_for_cxx(fd: RawFd, buf: &mut [u8]) -> isize {
     fd_path(fd, buf)
         .context("fd_path failed")
         .log()
@@ -37,3 +41,19 @@ unsafe extern "C" fn frm_rf(fd: OwnedFd) -> bool {
     }
     inner(fd).map_or(false, |_| true)
 }
+
+pub(crate) fn map_file_for_cxx(path: &[u8], rw: bool) -> &'static mut [u8] {
+    unsafe {
+        map_file(CStr::from_bytes_with_nul_unchecked(path), rw)
+            .log()
+            .unwrap_or(&mut [])
+    }
+}
+
+pub(crate) fn map_fd_for_cxx(fd: RawFd, sz: usize, rw: bool) -> &'static mut [u8] {
+    unsafe {
+        map_fd(BorrowedFd::borrow_raw(fd), sz, rw)
+            .log()
+            .unwrap_or(&mut [])
+    }
+}

native/src/base/files.cpp

@@ -375,29 +375,19 @@ sFILE make_file(FILE *fp) {
 }
 
 mmap_data::mmap_data(const char *name, bool rw) {
-    int fd = xopen(name, (rw ? O_RDWR : O_RDONLY) | O_CLOEXEC);
+    auto slice = rust::map_file(byte_view(name), rw);
-    if (fd < 0)
+    if (!slice.empty()) {
-        return;
+        _buf = slice.data();
-
+        _sz = slice.size();
-    run_finally g([=] { close(fd); });
-    struct stat st{};
-    if (fstat(fd, &st))
-        return;
-    if (S_ISBLK(st.st_mode)) {
-        uint64_t size;
-        ioctl(fd, BLKGETSIZE64, &size);
-        init(fd, size, rw);
-    } else {
-        init(fd, st.st_size, rw);
     }
 }
 
-void mmap_data::init(int fd, size_t sz, bool rw) {
+mmap_data::mmap_data(int fd, size_t sz, bool rw) {
-    _sz = sz;
+    auto slice = rust::map_fd(fd, sz, rw);
-    void *b = sz > 0
+    if (!slice.empty()) {
-            ? xmmap(nullptr, sz, PROT_READ | PROT_WRITE, rw ? MAP_SHARED : MAP_PRIVATE, fd, 0)
+        _buf = slice.data();
-            : nullptr;
+        _sz = slice.size();
-    _buf = static_cast<uint8_t *>(b);
+    }
 }
 
 mmap_data::~mmap_data() {

native/src/base/files.hpp

@@ -45,10 +45,8 @@ struct mmap_data : public byte_data {
     ALLOW_MOVE_ONLY(mmap_data)
 
     explicit mmap_data(const char *name, bool rw = false);
-    mmap_data(int fd, size_t sz, bool rw = false) { init(fd, sz, rw); }
+    mmap_data(int fd, size_t sz, bool rw = false);
     ~mmap_data();
-private:
-    void init(int fd, size_t sz, bool rw);
 };
 
 extern "C" {

native/src/base/files.rs

@@ -7,20 +7,16 @@ use std::marker::PhantomData;
 use std::ops::Deref;
 use std::os::fd::{AsFd, BorrowedFd, IntoRawFd};
 use std::os::unix::io::{AsRawFd, FromRawFd, OwnedFd, RawFd};
-use std::{io, mem, slice};
+use std::{io, mem, ptr, slice};
 
-use libc::{c_char, c_uint, dirent, mode_t, EEXIST, ENOENT, O_CLOEXEC, O_PATH, O_RDONLY};
+use libc::{c_char, c_uint, dirent, mode_t, EEXIST, ENOENT, O_CLOEXEC, O_PATH, O_RDONLY, O_RDWR};
 
-use crate::{bfmt_cstr, copy_cstr, cstr, errno, error};
+use crate::{bfmt_cstr, copy_cstr, cstr, errno, error, LibcReturn};
 
 pub fn __open_fd_impl(path: &CStr, flags: i32, mode: mode_t) -> io::Result<OwnedFd> {
     unsafe {
-        let fd = libc::open(path.as_ptr(), flags, mode as c_uint);
+        let fd = libc::open(path.as_ptr(), flags, mode as c_uint).check_os_err()?;
-        if fd >= 0 {
         Ok(OwnedFd::from_raw_fd(fd))
-        } else {
-            Err(io::Error::last_os_error())
-        }
     }
 }
 
@@ -43,10 +39,8 @@ pub unsafe fn readlink_unsafe(path: *const c_char, buf: *mut u8, bufsz: usize) -
 }
 
 pub fn readlink(path: &CStr, data: &mut [u8]) -> io::Result<usize> {
-    let r = unsafe { readlink_unsafe(path.as_ptr(), data.as_mut_ptr(), data.len()) };
+    let r =
-    if r < 0 {
+        unsafe { readlink_unsafe(path.as_ptr(), data.as_mut_ptr(), data.len()) }.check_os_err()?;
-        return Err(io::Error::last_os_error());
-    }
     Ok(r as usize)
 }
 
@@ -229,9 +223,7 @@ impl DirEntry<'_> {
     pub fn unlink(&self) -> io::Result<()> {
         let flag = if self.is_dir() { libc::AT_REMOVEDIR } else { 0 };
         unsafe {
-            if libc::unlinkat(self.dir.as_raw_fd(), self.d_name.as_ptr(), flag) < 0 {
+            libc::unlinkat(self.dir.as_raw_fd(), self.d_name.as_ptr(), flag).check_os_err()?;
-                return Err(io::Error::last_os_error());
-            }
         }
         Ok(())
     }
@@ -245,10 +237,8 @@ impl DirEntry<'_> {
                 self.dir.as_raw_fd(),
                 self.d_name.as_ptr(),
                 O_RDONLY | O_CLOEXEC,
-            );
+            )
-            if fd < 0 {
+            .check_os_err()?;
-                return Err(io::Error::last_os_error());
-            }
             Directory::try_from(OwnedFd::from_raw_fd(fd))
         }
     }
@@ -262,10 +252,8 @@ impl DirEntry<'_> {
                 self.dir.as_raw_fd(),
                 self.d_name.as_ptr(),
                 flags | O_CLOEXEC,
-            );
+            )
-            if fd < 0 {
+            .check_os_err()?;
-                return Err(io::Error::last_os_error());
-            }
             Ok(File::from_raw_fd(fd))
         }
     }
@@ -292,10 +280,7 @@ pub enum WalkResult {
 
 impl<'a> Directory<'a> {
     pub fn open(path: &CStr) -> io::Result<Directory> {
-        let dirp = unsafe { libc::opendir(path.as_ptr()) };
+        let dirp = unsafe { libc::opendir(path.as_ptr()) }.check_os_err()?;
-        if dirp.is_null() {
-            return Err(io::Error::last_os_error());
-        }
         Ok(Directory {
             dirp,
             _phantom: PhantomData,
@@ -415,10 +400,7 @@ impl TryFrom<OwnedFd> for Directory<'_> {
     type Error = io::Error;
 
     fn try_from(fd: OwnedFd) -> io::Result<Self> {
-        let dirp = unsafe { libc::fdopendir(fd.into_raw_fd()) };
+        let dirp = unsafe { libc::fdopendir(fd.into_raw_fd()) }.check_os_err()?;
-        if dirp.is_null() {
-            return Err(io::Error::last_os_error());
-        }
         Ok(Directory {
             dirp,
             _phantom: PhantomData,
@@ -449,16 +431,131 @@ impl Drop for Directory<'_> {
 pub fn rm_rf(path: &CStr) -> io::Result<()> {
     unsafe {
         let mut stat: libc::stat = mem::zeroed();
-        if libc::lstat(path.as_ptr(), &mut stat) < 0 {
+        libc::lstat(path.as_ptr(), &mut stat).check_os_err()?;
-            return Err(io::Error::last_os_error());
+        if stat.is_dir() {
-        }
-        if (stat.st_mode & libc::S_IFMT as u32) == libc::S_IFDIR as u32 {
             let mut dir = Directory::open(path)?;
             dir.remove_all()?;
         }
-        if libc::remove(path.as_ptr()) < 0 {
+        libc::remove(path.as_ptr()).check_os_err()?;
-            return Err(io::Error::last_os_error());
-        }
     }
     Ok(())
 }
+
+pub trait StatExt {
+    fn get_mode(&self) -> u32;
+    fn get_type(&self) -> u32;
+
+    fn is_dir(&self) -> bool;
+    fn is_blk(&self) -> bool;
+}
+
+impl StatExt for libc::stat {
+    fn get_mode(&self) -> u32 {
+        self.st_mode & libc::S_IFMT as u32
+    }
+
+    fn get_type(&self) -> u32 {
+        self.st_mode & !(libc::S_IFMT as u32)
+    }
+
+    fn is_dir(&self) -> bool {
+        self.get_type() == libc::S_IFDIR as u32
+    }
+
+    fn is_blk(&self) -> bool {
+        self.get_type() == libc::S_IFBLK as u32
+    }
+}
+
+pub trait FdExt {
+    fn size(&self) -> io::Result<usize>;
+}
+
+const BLKGETSIZE64: u32 = 0x80081272;
+
+impl<T: AsRawFd> FdExt for T {
+    fn size(&self) -> io::Result<usize> {
+        unsafe fn inner(fd: RawFd) -> io::Result<usize> {
+            extern "C" {
+                // Don't use the declaration from the libc crate as request should be u32 not i32
+                fn ioctl(fd: RawFd, request: u32, ...) -> i32;
+            }
+            let mut stat: libc::stat = mem::zeroed();
+            libc::fstat(fd, &mut stat).check_os_err()?;
+            if stat.is_blk() {
+                let mut sz = 0_u64;
+                ioctl(fd, BLKGETSIZE64, &mut sz).check_os_err()?;
+                Ok(sz as usize)
+            } else {
+                Ok(stat.st_size as usize)
+            }
+        }
+
+        unsafe { inner(self.as_raw_fd()) }
+    }
+}
+
+pub struct MappedFile(&'static mut [u8]);
+
+impl MappedFile {
+    pub fn open(path: &CStr) -> io::Result<MappedFile> {
+        Ok(MappedFile(map_file(path, false)?))
+    }
+
+    pub fn open_rw(path: &CStr) -> io::Result<MappedFile> {
+        Ok(MappedFile(map_file(path, true)?))
+    }
+
+    pub fn create(fd: BorrowedFd, sz: usize, rw: bool) -> io::Result<MappedFile> {
+        Ok(MappedFile(map_fd(fd, sz, rw)?))
+    }
+}
+
+impl AsRef<[u8]> for MappedFile {
+    fn as_ref(&self) -> &[u8] {
+        self.0
+    }
+}
+
+impl AsMut<[u8]> for MappedFile {
+    fn as_mut(&mut self) -> &mut [u8] {
+        self.0
+    }
+}
+
+impl Drop for MappedFile {
+    fn drop(&mut self) {
+        unsafe {
+            libc::munmap(self.0.as_mut_ptr().cast(), self.0.len());
+        }
+    }
+}
+
+// We mark the returned slice static because it is valid until explicitly unmapped
+pub(crate) fn map_file(path: &CStr, rw: bool) -> io::Result<&'static mut [u8]> {
+    let flag = if rw { O_RDONLY } else { O_RDWR };
+    let fd = open_fd!(path, flag | O_CLOEXEC)?;
+    map_fd(fd.as_fd(), fd.size()?, rw)
+}
+
+pub(crate) fn map_fd(fd: BorrowedFd, sz: usize, rw: bool) -> io::Result<&'static mut [u8]> {
+    let flag = if rw {
+        libc::MAP_SHARED
+    } else {
+        libc::MAP_PRIVATE
+    };
+    unsafe {
+        let ptr = libc::mmap(
+            ptr::null_mut(),
+            sz,
+            libc::PROT_READ | libc::PROT_WRITE,
+            flag,
+            fd.as_raw_fd(),
+            0,
+        );
+        if ptr == libc::MAP_FAILED {
+            return Err(io::Error::last_os_error());
+        }
+        Ok(slice::from_raw_parts_mut(ptr.cast(), sz))
+    }
+}

native/src/base/lib.rs

@@ -38,5 +38,9 @@ pub mod ffi {
         fn xpipe2(fds: &mut [i32; 2], flags: i32) -> i32;
         #[rust_name = "fd_path_for_cxx"]
         fn fd_path(fd: i32, buf: &mut [u8]) -> isize;
+        #[rust_name = "map_file_for_cxx"]
+        fn map_file(path: &[u8], rw: bool) -> &'static mut [u8];
+        #[rust_name = "map_fd_for_cxx"]
+        fn map_fd(fd: i32, sz: usize, rw: bool) -> &'static mut [u8];
     }
 }

native/src/base/misc.rs

@@ -1,9 +1,12 @@
 use std::cmp::min;
-use std::ffi::CStr;
+use std::ffi::{CStr, FromBytesWithNulError, OsStr};
-use std::fmt::{Arguments, Debug};
+use std::fmt::{Arguments, Debug, Display, Formatter};
+use std::ops::Deref;
+use std::path::Path;
 use std::str::Utf8Error;
-use std::{fmt, slice};
+use std::{fmt, io, slice, str};
 
+use libc::c_char;
 use thiserror::Error;
 
 pub fn copy_str<T: AsRef<[u8]>>(dest: &mut [u8], src: T) -> usize {
@@ -96,14 +99,120 @@ macro_rules! raw_cstr {
 #[derive(Debug, Error)]
 pub enum StrErr {
     #[error(transparent)]
-    Invalid(#[from] Utf8Error),
+    Utf8Error(#[from] Utf8Error),
+    #[error(transparent)]
+    CStrError(#[from] FromBytesWithNulError),
     #[error("argument is null")]
-    NullPointer,
+    NullPointerError,
+}
+
+// The better CStr: UTF-8 validated + null terminated buffer
+pub struct Utf8CStr {
+    inner: [u8],
+}
+
+impl Utf8CStr {
+    pub fn from_cstr(cstr: &CStr) -> Result<&Utf8CStr, StrErr> {
+        // Validate the buffer during construction
+        str::from_utf8(cstr.to_bytes())?;
+        Ok(unsafe { Self::from_bytes_unchecked(cstr.to_bytes_with_nul()) })
+    }
+
+    pub fn from_bytes(buf: &[u8]) -> Result<&Utf8CStr, StrErr> {
+        Self::from_cstr(CStr::from_bytes_with_nul(buf)?)
+    }
+
+    pub fn from_string(s: &mut String) -> &Utf8CStr {
+        if s.capacity() == s.len() {
+            s.reserve(1);
+        }
+        // SAFETY: the string is reserved to have enough capacity to fit in the null byte
+        // SAFETY: the null byte is explicitly added outside of the string's length
+        unsafe {
+            let buf = slice::from_raw_parts_mut(s.as_mut_ptr(), s.len() + 1);
+            *buf.get_unchecked_mut(s.len()) = b'\0';
+            Self::from_bytes_unchecked(buf)
+        }
+    }
+
+    pub unsafe fn from_bytes_unchecked(buf: &[u8]) -> &Utf8CStr {
+        &*(buf as *const [u8] as *const Utf8CStr)
+    }
+
+    pub unsafe fn from_ptr<'a>(ptr: *const c_char) -> Result<&'a Utf8CStr, StrErr> {
+        if ptr.is_null() {
+            return Err(StrErr::NullPointerError);
+        }
+        Self::from_cstr(unsafe { CStr::from_ptr(ptr) })
+    }
+
+    pub fn as_bytes(&self) -> &[u8] {
+        // The length of the slice is at least 1 due to null termination check
+        unsafe { self.inner.get_unchecked(..self.inner.len() - 1) }
+    }
+
+    pub fn as_bytes_with_nul(&self) -> &[u8] {
+        &self.inner
+    }
+
+    pub fn as_ptr(&self) -> *const c_char {
+        self.inner.as_ptr().cast()
+    }
+}
+
+impl Deref for Utf8CStr {
+    type Target = str;
+
+    fn deref(&self) -> &str {
+        self.as_ref()
+    }
+}
+
+impl Display for Utf8CStr {
+    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
+        Display::fmt(self.deref(), f)
+    }
+}
+
+impl Debug for Utf8CStr {
+    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
+        Debug::fmt(self.deref(), f)
+    }
+}
+
+impl AsRef<CStr> for Utf8CStr {
+    #[inline]
+    fn as_ref(&self) -> &CStr {
+        // SAFETY: Already validated as null terminated during construction
+        unsafe { CStr::from_bytes_with_nul_unchecked(&self.inner) }
+    }
+}
+
+impl AsRef<str> for Utf8CStr {
+    #[inline]
+    fn as_ref(&self) -> &str {
+        // SAFETY: Already UTF-8 validated during construction
+        unsafe { str::from_utf8_unchecked(self.as_bytes()) }
+    }
+}
+
+impl AsRef<OsStr> for Utf8CStr {
+    #[inline]
+    fn as_ref(&self) -> &OsStr {
+        OsStr::new(self)
+    }
+}
+
+impl AsRef<Path> for Utf8CStr {
+    #[inline]
+    fn as_ref(&self) -> &Path {
+        Path::new(self)
+    }
 }
 
 pub fn ptr_to_str_result<'a, T>(ptr: *const T) -> Result<&'a str, StrErr> {
     if ptr.is_null() {
-        Err(StrErr::NullPointer)
+        Err(StrErr::NullPointerError)
     } else {
         unsafe { CStr::from_ptr(ptr.cast()) }
             .to_str()
@@ -167,3 +276,38 @@ pub trait FlatData {
         }
     }
 }
+
+// Check libc return value and map errors to Result
+pub trait LibcReturn: Copy {
+    fn is_error(&self) -> bool;
+    fn check_os_err(self) -> io::Result<Self> {
+        if self.is_error() {
+            return Err(io::Error::last_os_error());
+        }
+        Ok(self)
+    }
+}
+
+impl LibcReturn for i32 {
+    fn is_error(&self) -> bool {
+        *self < 0
+    }
+}
+
+impl LibcReturn for isize {
+    fn is_error(&self) -> bool {
+        *self < 0
+    }
+}
+
+impl<T> LibcReturn for *const T {
+    fn is_error(&self) -> bool {
+        self.is_null()
+    }
+}
+
+impl<T> LibcReturn for *mut T {
+    fn is_error(&self) -> bool {
+        self.is_null()
+    }
+}

native/src/boot/cpio.rs

@@ -4,21 +4,21 @@ use std::fmt::{Display, Formatter};
 use std::fs::{metadata, read, DirBuilder, File};
 use std::io::Write;
 use std::mem::size_of;
-use std::os::fd::AsRawFd;
 use std::os::unix::fs::{symlink, DirBuilderExt, FileTypeExt, MetadataExt};
 use std::path::Path;
 use std::process::exit;
+use std::slice;
 
 use anyhow::{anyhow, Context};
 use clap::{Parser, Subcommand};
 use size::{Base, Size, Style};
 
 use base::libc::{
-    c_char, dev_t, gid_t, major, makedev, minor, mknod, mmap, mode_t, munmap, uid_t, MAP_FAILED,
+    c_char, dev_t, gid_t, major, makedev, minor, mknod, mode_t, uid_t, S_IFBLK, S_IFCHR, S_IFDIR,
-    MAP_PRIVATE, PROT_READ, S_IFBLK, S_IFCHR, S_IFDIR, S_IFLNK, S_IFMT, S_IFREG, S_IRGRP, S_IROTH,
+    S_IFLNK, S_IFMT, S_IFREG, S_IRGRP, S_IROTH, S_IRUSR, S_IWGRP, S_IWOTH, S_IWUSR, S_IXGRP,
-    S_IRUSR, S_IWGRP, S_IWOTH, S_IWUSR, S_IXGRP, S_IXOTH, S_IXUSR,
+    S_IXOTH, S_IXUSR,
 };
-use base::{ptr_to_str_result, ResultExt, WriteExt};
+use base::{MappedFile, ResultExt, StrErr, Utf8CStr, WriteExt};
 
 use crate::ramdisk::MagiskCpio;
 
@@ -152,31 +152,10 @@ impl Cpio {
         Ok(cpio)
     }
 
-    pub(crate) fn load_from_file(path: &str) -> anyhow::Result<Self> {
+    pub(crate) fn load_from_file(path: &Utf8CStr) -> anyhow::Result<Self> {
         eprintln!("Loading cpio: [{}]", path);
-        let file = File::open(path)?;
+        let data = MappedFile::open(path.as_ref())?;
-        let len = file.metadata()?.len() as usize;
+        Self::load_from_data(data.as_ref())
-        let mmap = unsafe {
-            mmap(
-                std::ptr::null_mut(),
-                len,
-                PROT_READ,
-                MAP_PRIVATE,
-                file.as_raw_fd(),
-                0,
-            )
-        };
-        if mmap == MAP_FAILED {
-            return Err(anyhow!("mmap failed"));
-        }
-        let data = unsafe { std::slice::from_raw_parts(mmap as *const u8, len) };
-        let cpio = Self::load_from_data(data)?;
-        unsafe {
-            if munmap(mmap, len) != 0 {
-                return Err(anyhow!("munmap failed"));
-            }
-        }
-        Ok(cpio)
     }
 
     fn dump(&self, path: &str) -> anyhow::Result<()> {
@@ -435,19 +414,18 @@ impl Display for CpioEntry {
 
 pub fn cpio_commands(argc: i32, argv: *const *const c_char) -> bool {
     fn inner(argc: i32, argv: *const *const c_char) -> anyhow::Result<()> {
-        let mut cmds = Vec::new();
         if argc < 1 {
             return Err(anyhow!("no arguments"));
         }
-        for i in 0..argc {
-            let arg = unsafe { ptr_to_str_result(*argv.offset(i as isize)) };
-            match arg {
-                Ok(arg) => cmds.push(arg),
-                Err(e) => Err(e)?,
-            }
-        }
-        let file = cmds[0];
 
+        let cmds: Result<Vec<&Utf8CStr>, StrErr> =
+            unsafe { slice::from_raw_parts(argv, argc as usize) }
+                .iter()
+                .map(|s| unsafe { Utf8CStr::from_ptr(*s) })
+                .collect();
+        let cmds = cmds?;
+
+        let file = cmds[0];
         let mut cpio = if Path::new(file).exists() {
             Cpio::load_from_file(file)?
         } else {
@@ -458,8 +436,8 @@ pub fn cpio_commands(argc: i32, argv: *const *const c_char) -> bool {
                 continue;
             }
             let cmd = "magiskboot ".to_string() + cmd;
-            let cli = CpioCli::try_parse_from(cmd.split(' ').filter(|x| !x.is_empty()))?;
+            let mut cli = CpioCli::try_parse_from(cmd.split(' ').filter(|x| !x.is_empty()))?;
-            match &cli.command {
+            match &mut cli.command {
                 CpioCommands::Test {} => exit(cpio.test()),
                 CpioCommands::Restore {} => cpio.restore()?,
                 CpioCommands::Patch {} => cpio.patch(),
@@ -470,7 +448,9 @@ pub fn cpio_commands(argc: i32, argv: *const *const c_char) -> bool {
                         exit(1);
                     }
                 }
-                CpioCommands::Backup { origin } => cpio.backup(origin)?,
+                CpioCommands::Backup { ref mut origin } => {
+                    cpio.backup(Utf8CStr::from_string(origin))?
+                }
                 CpioCommands::Rm { path, recursive } => cpio.rm(path, *recursive),
                 CpioCommands::Mv { from, to } => cpio.mv(from, to)?,
                 CpioCommands::Extract { path, out } => {

native/src/boot/payload.rs

@@ -196,12 +196,12 @@ pub fn extract_boot_from_payload(
         let in_path = ptr_to_str_result(in_path)?;
         let partition = match ptr_to_str_result(partition) {
             Ok(s) => Some(s),
-            Err(StrErr::NullPointer) => None,
+            Err(StrErr::NullPointerError) => None,
             Err(e) => Err(e)?,
         };
         let out_path = match ptr_to_str_result(out_path) {
             Ok(s) => Some(s),
-            Err(StrErr::NullPointer) => None,
+            Err(StrErr::NullPointerError) => None,
             Err(e) => Err(e)?,
         };
         do_extract_boot_from_payload(in_path, partition, out_path)

native/src/boot/ramdisk.rs

@@ -4,6 +4,7 @@ use std::env;
 use std::str::from_utf8;
 
 use base::libc::{S_IFDIR, S_IFMT, S_IFREG};
+use base::Utf8CStr;
 
 use crate::cpio::{Cpio, CpioEntry};
 use crate::ffi::{patch_encryption, patch_verity};
@@ -12,7 +13,7 @@ pub trait MagiskCpio {
     fn patch(&mut self);
     fn test(&self) -> i32;
     fn restore(&mut self) -> anyhow::Result<()>;
-    fn backup(&mut self, origin: &str) -> anyhow::Result<()>;
+    fn backup(&mut self, origin: &Utf8CStr) -> anyhow::Result<()>;
 }
 
 const MAGISK_PATCHED: i32 = 1 << 0;
@@ -119,7 +120,7 @@ impl MagiskCpio for Cpio {
         Ok(())
     }
 
-    fn backup(&mut self, origin: &str) -> anyhow::Result<()> {
+    fn backup(&mut self, origin: &Utf8CStr) -> anyhow::Result<()> {
         let mut backups = HashMap::<String, CpioEntry>::new();
         let mut rm_list = String::new();
         backups.insert(