Struct KernelFeatures 

pub struct KernelFeatures {

    pub bpf_v2: bool,
    pub devtmpfs: bool,
    pub enable_suid: bool,
    pub io_uring: bool,
    pub error_on_failed_reboot: bool,
    pub default_seclabel: Option<String>,
    pub selinux_test_suite: bool,
    pub default_ns_mount_options: Option<HashMap<String, String>>,
    pub default_uid: u32,
    pub mlock_always_onfault: bool,
    pub mlock_pin_flavor: MlockPinFlavor,
    pub crash_report_throttling: bool,
    pub wifi: bool,
    pub cached_zx_map_info_bytes: u32,
    pub dirent_cache_size: u32,
    pub fake_ion: bool,
    pub remotevol_in_process: bool,
    pub log_sysfs_lookup_misses: bool,
    pub oom_watermarks_mb: Option<OomWatermarksMb>,
    pub stop_last_on_shutdown: Vec<FsString>,
}

Kernel features are specified in the component manifest of the starnix container or explicitly provided to the kernel constructor in tests.

Fields

bpf_v2: bool

devtmpfs: bool

Whether the devtmpfs filesystem and automatic device node creation are enabled.

enable_suid: bool

Whether the kernel supports the S_ISUID and S_ISGID bits.

For example, these bits are used by sudo.

Enabling this feature is potentially a security risk because they allow privilege escalation.

io_uring: bool

Whether io_uring is enabled.

TODO(https://fxbug.dev/297431387): Enabled by default once the feature is completed.

error_on_failed_reboot: bool

Whether the kernel should return an error to userspace, rather than panicking, if reboot() is requested but cannot be enacted because the kernel lacks the relevant capabilities.

default_seclabel: Option<String>

The default seclabel that is applied to components that are run in this kernel.

Components can override this by setting the seclabel field in their program block.

selinux_test_suite: bool

Whether the kernel is being used to run the SELinux Test Suite.

TODO: https://fxbug.dev/388077431 - remove this once we no longer need workarounds for the SELinux Test Suite.

default_ns_mount_options: Option<HashMap<String, String>>

The default mount options to use when mounting directories from a component’s namespace.

The key is the path in the component’s namespace, and the value is the mount options string.

default_uid: u32

The default uid that is applied to components that are run in this kernel.

Components can override this by setting the uid field in their program block.

mlock_always_onfault: bool

mlock() never prefaults pages.

mlock_pin_flavor: MlockPinFlavor

Implementation of mlock() to use for this kernel instance.

crash_report_throttling: bool

Whether excessive crash reports should be throttled.

wifi: bool

Whether or not to serve wifi support to Android.

cached_zx_map_info_bytes: u32

The number of bytes to cache in pages for reading zx::MapInfo from VMARs.

dirent_cache_size: u32

The size of the Dirent LRU cache.

fake_ion: bool

Whether to expose a stub ‘/dev/ion’ node, as a temporary workaround for compatibility.

remotevol_in_process: bool

Whether remotevol mounts the volume in-process rather than over FIDL.

log_sysfs_lookup_misses: bool

Whether to log unexpected lookup misses in sysfs via track_stub_log!.

oom_watermarks_mb: Option<OomWatermarksMb>

Free-memory watermarks (in MiB) for /proc/zoneinfo.

stop_last_on_shutdown: Vec<FsString>

Paths of executables whose processes are stopped only after all other processes except init have exited when the kernel shuts down, e.g. one that writes crash dumps for processes that crash during shutdown. See Kernel::run_shutdown().

Implementations

impl KernelFeatures

pub fn ns_mount_options(&self, ns_path: &str) -> Result<MountParams, Errno>

Returns the MountParams to use when mounting the specified path from a component’s namespace. This mechanism is also used to specified options for mounts created via container features, by specifying a pseudo-path e.g. “#container”.

Trait Implementations

impl Clone for KernelFeatures

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for KernelFeatures

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for KernelFeatures

fn default() -> Self

Returns the “default value” for a type.