ksud: Add cli interface for nuke_ext4_sysfs

userspace/ksud/src/cli.rs

@@ -152,6 +152,11 @@ enum Commands {
         #[command(subcommand)]
         command: Debug,
     },
+    /// Kernel interface
+    Kernel {
+        #[command(subcommand)]
+        command: Kernel,
+    },
 }
 
 #[derive(clap::Subcommand, Debug)]
@@ -378,6 +383,15 @@ enum Feature {
     Save,
 }
 
+#[derive(clap::Subcommand, Debug)]
+enum Kernel {
+    /// Nuke ext4 sysfs
+    NukeExt4Sysfs {
+        /// mount point
+        mnt: String,
+    },
+}
+
 #[cfg(target_arch = "aarch64")]
 mod kpm_cmd {
     use clap::Subcommand;
@@ -590,6 +604,9 @@ pub fn run() -> Result<()> {
             magiskboot,
             flash,
         } => crate::boot_patch::restore(boot, magiskboot, flash),
+        Commands::Kernel { command } => match command {
+            Kernel::NukeExt4Sysfs { mnt } => ksucalls::nuke_ext4_sysfs(&mnt),
+        },
         #[cfg(target_arch = "aarch64")]
         Commands::Kpm { command } => {
             use crate::cli::kpm_cmd::Kpm;

userspace/ksud/src/ksucalls.rs

@@ -17,6 +17,7 @@ const KSU_IOCTL_GET_FEATURE: u32 = 0xc0004b0d; // _IOC(_IOC_READ|_IOC_WRITE, 'K'
 const KSU_IOCTL_SET_FEATURE: u32 = 0x40004b0e; // _IOC(_IOC_WRITE, 'K', 14, 0)
 const KSU_IOCTL_GET_WRAPPER_FD: u32 = 0x40004b0f; // _IOC(_IOC_WRITE, 'K', 15, 0)
 const KSU_IOCTL_MANAGE_MARK: u32 = 0xc0004b10; // _IOC(_IOC_READ|_IOC_WRITE, 'K', 16, 0)
+const KSU_IOCTL_NUKE_EXT4_SYSFS: u32 = 0xc0004b11; // _IOC(_IOC_READ|_IOC_WRITE, 'K', 17, 0)
 
 #[repr(C)]
 #[derive(Clone, Copy, Default)]
@@ -73,6 +74,12 @@ struct ManageMarkCmd {
     result: u32,
 }
 
+#[repr(C)]
+#[derive(Clone, Copy, Default)]
+pub struct NukeExt4SysfsCmd {
+    pub arg: u64,
+}
+
 // Mark operation constants
 const KSU_MARK_GET: u32 = 1;
 const KSU_MARK_MARK: u32 = 2;
@@ -294,3 +301,12 @@ pub fn mark_refresh() -> std::io::Result<()> {
     ksuctl(KSU_IOCTL_MANAGE_MARK, &mut cmd as *mut _)?;
     Ok(())
 }
+
+pub fn nuke_ext4_sysfs(mnt: &str) -> anyhow::Result<()> {
+    let c_mnt = std::ffi::CString::new(mnt)?;
+    let mut ioctl_cmd = NukeExt4SysfsCmd {
+        arg: c_mnt.as_ptr() as u64,
+    };
+    ksuctl(KSU_IOCTL_NUKE_EXT4_SYSFS, &mut ioctl_cmd as *mut _)?;
+    Ok(())
+}

userspace/meta-overlayfs/metamodule/post-mount.sh

@@ -0,0 +1,3 @@
+#!/system/bin/sh
+
+ksud kernel nuke-ext4-sysfs /data/adb/modules/meta-overlayfs/mnt