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//! Linux `prctl` wrappers.
//!
//! Rustix wraps variadic/dynamic-dispatch functions like `prctl` in
//! type-safe wrappers.
//!
//! # Safety
//!
//! The inner `prctl` calls are dynamically typed and must be called
//! correctly.
#![allow(unsafe_code)]
use core::mem::MaybeUninit;
use core::num::NonZeroU64;
use core::ptr;
use core::ptr::NonNull;
use core::sync::atomic::AtomicU8;
use bitflags::bitflags;
use crate::backend::c::{c_int, c_uint, c_void};
use crate::backend::prctl::syscalls;
use crate::ffi::CStr;
#[cfg(feature = "alloc")]
use crate::ffi::CString;
use crate::io;
use crate::pid::Pid;
use crate::prctl::{
prctl_1arg, prctl_2args, prctl_3args, prctl_get_at_arg2_optional, PointerAuthenticationKeys,
};
use crate::utils::as_ptr;
//
// PR_GET_KEEPCAPS/PR_SET_KEEPCAPS
//
const PR_GET_KEEPCAPS: c_int = 7;
/// Get the current state of the calling thread's `keep capabilities` flag.
///
/// # References
/// - [`prctl(PR_GET_KEEPCAPS,...)`]
///
#[inline]
pub fn get_keep_capabilities() -> io::Result<bool> {
unsafe { prctl_1arg(PR_GET_KEEPCAPS) }.map(|r| r != 0)
}
const PR_SET_KEEPCAPS: c_int = 8;
/// Set the state of the calling thread's `keep capabilities` flag.
///
/// # References
/// - [`prctl(PR_SET_KEEPCAPS,...)`]
///
#[inline]
pub fn set_keep_capabilities(enable: bool) -> io::Result<()> {
unsafe { prctl_2args(PR_SET_KEEPCAPS, usize::from(enable) as *mut _) }.map(|_r| ())
}
//
// PR_GET_NAME/PR_SET_NAME
//
#[cfg(feature = "alloc")]
const PR_GET_NAME: c_int = 16;
/// Get the name of the calling thread.
///
/// # References
/// - [`prctl(PR_GET_NAME,...)`]
///
#[inline]
#[cfg(feature = "alloc")]
pub fn name() -> io::Result<CString> {
let mut buffer = [0_u8; 16];
unsafe { prctl_2args(PR_GET_NAME, buffer.as_mut_ptr().cast())? };
let len = buffer.iter().position(|&x| x == 0_u8).unwrap_or(0);
CString::new(&buffer[..len]).map_err(|_r| io::Errno::ILSEQ)
}
const PR_SET_NAME: c_int = 15;
/// Set the name of the calling thread.
///
/// Unlike `pthread_setname_np`, this function silently truncates the name to
/// 16 bytes, as the Linux syscall does.
///
/// # References
/// - [`prctl(PR_SET_NAME,...)`]
///
#[inline]
pub fn set_name(name: &CStr) -> io::Result<()> {
unsafe { prctl_2args(PR_SET_NAME, name.as_ptr() as *mut _) }.map(|_r| ())
}
//
// PR_GET_SECCOMP/PR_SET_SECCOMP
//
//const PR_GET_SECCOMP: c_int = 21;
const SECCOMP_MODE_DISABLED: i32 = 0;
const SECCOMP_MODE_STRICT: i32 = 1;
const SECCOMP_MODE_FILTER: i32 = 2;
/// `SECCOMP_MODE_*`.
#[derive(Copy, Clone, Debug, Eq, PartialEq)]
#[repr(i32)]
pub enum SecureComputingMode {
/// Secure computing is not in use.
Disabled = SECCOMP_MODE_DISABLED,
/// Use hard-coded filter.
Strict = SECCOMP_MODE_STRICT,
/// Use user-supplied filter.
Filter = SECCOMP_MODE_FILTER,
}
impl TryFrom<i32> for SecureComputingMode {
type Error = io::Errno;
fn try_from(value: i32) -> Result<Self, Self::Error> {
match value {
SECCOMP_MODE_DISABLED => Ok(Self::Disabled),
SECCOMP_MODE_STRICT => Ok(Self::Strict),
SECCOMP_MODE_FILTER => Ok(Self::Filter),
_ => Err(io::Errno::RANGE),
}
}
}
/*
/// Get the secure computing mode of the calling thread.
///
/// If the caller is not in secure computing mode, this returns
/// [`SecureComputingMode::Disabled`]. If the caller is in strict secure
/// computing mode, then this call will cause a [`Signal::Kill`] signal to be
/// sent to the process. If the caller is in filter mode, and this system call
/// is allowed by the seccomp filters, it returns
/// [`SecureComputingMode::Filter`]; otherwise, the process is killed with a
/// [`Signal::Kill`] signal.
///
/// Since Linux 3.8, the Seccomp field of the `/proc/[pid]/status` file
/// provides a method of obtaining the same information, without the risk that
/// the process is killed; see [the `proc` manual page].
///
/// # References
/// - [`prctl(PR_GET_SECCOMP,...)`]
///
#[inline]
pub fn secure_computing_mode() -> io::Result<SecureComputingMode> {
unsafe { prctl_1arg(PR_GET_SECCOMP) }.and_then(TryInto::try_into)
}
*/
const PR_SET_SECCOMP: c_int = 22;
/// Set the secure computing mode for the calling thread, to limit the
/// available system calls.
///
/// # References
/// - [`prctl(PR_SET_SECCOMP,...)`]
///
#[inline]
pub fn set_secure_computing_mode(mode: SecureComputingMode) -> io::Result<()> {
unsafe { prctl_2args(PR_SET_SECCOMP, mode as usize as *mut _) }.map(|_r| ())
}
//
// PR_CAPBSET_READ/PR_CAPBSET_DROP
//
const PR_CAPBSET_READ: c_int = 23;
/// Linux per-thread capability.
#[derive(Copy, Clone, Debug, Eq, PartialEq)]
#[repr(u32)]
pub enum Capability {
/// In a system with the `_POSIX_CHOWN_RESTRICTED` option defined, this
/// overrides the restriction of changing file ownership and group
/// ownership.
ChangeOwnership = linux_raw_sys::general::CAP_CHOWN,
/// Override all DAC access, including ACL execute access if `_POSIX_ACL`
/// is defined. Excluding DAC access covered by
/// [`Capability::LinuxImmutable`].
DACOverride = linux_raw_sys::general::CAP_DAC_OVERRIDE,
/// Overrides all DAC restrictions regarding read and search on files and
/// directories, including ACL restrictions if `_POSIX_ACL` is defined.
/// Excluding DAC access covered by [`Capability::LinuxImmutable`].
DACReadSearch = linux_raw_sys::general::CAP_DAC_READ_SEARCH,
/// Overrides all restrictions about allowed operations on files, where
/// file owner ID must be equal to the user ID, except where
/// [`Capability::FileSetID`] is applicable. It doesn't override MAC
/// and DAC restrictions.
FileOwner = linux_raw_sys::general::CAP_FOWNER,
/// Overrides the following restrictions that the effective user ID shall
/// match the file owner ID when setting the `S_ISUID` and `S_ISGID`
/// bits on that file; that the effective group ID (or one of the
/// supplementary group IDs) shall match the file owner ID when setting the
/// `S_ISGID` bit on that file; that the `S_ISUID` and `S_ISGID` bits are
/// cleared on successful return from `chown` (not implemented).
FileSetID = linux_raw_sys::general::CAP_FSETID,
/// Overrides the restriction that the real or effective user ID of a
/// process sending a signal must match the real or effective user ID of
/// the process receiving the signal.
Kill = linux_raw_sys::general::CAP_KILL,
/// Allows `setgid` manipulation. Allows `setgroups`. Allows forged gids on
/// socket credentials passing.
SetGroupID = linux_raw_sys::general::CAP_SETGID,
/// Allows `set*uid` manipulation (including fsuid). Allows forged pids on
/// socket credentials passing.
SetUserID = linux_raw_sys::general::CAP_SETUID,
/// Without VFS support for capabilities:
/// - Transfer any capability in your permitted set to any pid.
/// - remove any capability in your permitted set from any pid. With VFS
/// support for capabilities (neither of above, but)
/// - Add any capability from current's capability bounding set to the
/// current process' inheritable set.
/// - Allow taking bits out of capability bounding set.
/// - Allow modification of the securebits for a process.
SetPermittedCapabilities = linux_raw_sys::general::CAP_SETPCAP,
/// Allow modification of `S_IMMUTABLE` and `S_APPEND` file attributes.
LinuxImmutable = linux_raw_sys::general::CAP_LINUX_IMMUTABLE,
/// Allows binding to TCP/UDP sockets below 1024. Allows binding to ATM
/// VCIs below 32.
NetBindService = linux_raw_sys::general::CAP_NET_BIND_SERVICE,
/// Allow broadcasting, listen to multicast.
NetBroadcast = linux_raw_sys::general::CAP_NET_BROADCAST,
/// Allow interface configuration. Allow administration of IP firewall,
/// masquerading and accounting. Allow setting debug option on sockets.
/// Allow modification of routing tables. Allow setting arbitrary
/// process / process group ownership on sockets. Allow binding to any
/// address for transparent proxying (also via [`Capability::NetRaw`]).
/// Allow setting TOS (type of service). Allow setting promiscuous
/// mode. Allow clearing driver statistics. Allow multicasting. Allow
/// read/write of device-specific registers. Allow activation of ATM
/// control sockets.
NetAdmin = linux_raw_sys::general::CAP_NET_ADMIN,
/// Allow use of `RAW` sockets. Allow use of `PACKET` sockets. Allow
/// binding to any address for transparent proxying (also via
/// [`Capability::NetAdmin`]).
NetRaw = linux_raw_sys::general::CAP_NET_RAW,
/// Allow locking of shared memory segments. Allow mlock and mlockall
/// (which doesn't really have anything to do with IPC).
IPCLock = linux_raw_sys::general::CAP_IPC_LOCK,
/// Override IPC ownership checks.
IPCOwner = linux_raw_sys::general::CAP_IPC_OWNER,
/// Insert and remove kernel modules - modify kernel without limit.
SystemModule = linux_raw_sys::general::CAP_SYS_MODULE,
/// Allow ioperm/iopl access. Allow sending USB messages to any device via
/// `/dev/bus/usb`.
SystemRawIO = linux_raw_sys::general::CAP_SYS_RAWIO,
/// Allow use of `chroot`.
SystemChangeRoot = linux_raw_sys::general::CAP_SYS_CHROOT,
/// Allow `ptrace` of any process.
SystemProcessTrace = linux_raw_sys::general::CAP_SYS_PTRACE,
/// Allow configuration of process accounting.
SystemProcessAccounting = linux_raw_sys::general::CAP_SYS_PACCT,
/// Allow configuration of the secure attention key. Allow administration
/// of the random device. Allow examination and configuration of disk
/// quotas. Allow setting the domainname. Allow setting the hostname.
/// Allow `mount` and `umount`, setting up new smb connection.
/// Allow some autofs root ioctls. Allow nfsservctl. Allow
/// `VM86_REQUEST_IRQ`. Allow to read/write pci config on alpha. Allow
/// `irix_prctl` on mips (setstacksize). Allow flushing all cache on
/// m68k (`sys_cacheflush`). Allow removing semaphores. Used instead of
/// [`Capability::ChangeOwnership`] to "chown" IPC message queues,
/// semaphores and shared memory. Allow locking/unlocking of shared
/// memory segment. Allow turning swap on/off. Allow forged pids on
/// socket credentials passing. Allow setting readahead and
/// flushing buffers on block devices. Allow setting geometry in floppy
/// driver. Allow turning DMA on/off in `xd` driver. Allow
/// administration of md devices (mostly the above, but some
/// extra ioctls). Allow tuning the ide driver. Allow access to the nvram
/// device. Allow administration of `apm_bios`, serial and bttv (TV)
/// device. Allow manufacturer commands in isdn CAPI support driver.
/// Allow reading non-standardized portions of pci configuration space.
/// Allow DDI debug ioctl on sbpcd driver. Allow setting up serial ports.
/// Allow sending raw qic-117 commands. Allow enabling/disabling tagged
/// queuing on SCSI controllers and sending arbitrary SCSI commands.
/// Allow setting encryption key on loopback filesystem. Allow setting
/// zone reclaim policy. Allow everything under
/// [`Capability::BerkeleyPacketFilters`] and
/// [`Capability::PerformanceMonitoring`] for backward compatibility.
SystemAdmin = linux_raw_sys::general::CAP_SYS_ADMIN,
/// Allow use of `reboot`.
SystemBoot = linux_raw_sys::general::CAP_SYS_BOOT,
/// Allow raising priority and setting priority on other (different UID)
/// processes. Allow use of FIFO and round-robin (realtime) scheduling
/// on own processes and setting the scheduling algorithm used by
/// another process. Allow setting cpu affinity on other processes.
/// Allow setting realtime ioprio class. Allow setting ioprio class on
/// other processes.
SystemNice = linux_raw_sys::general::CAP_SYS_NICE,
/// Override resource limits. Set resource limits. Override quota limits.
/// Override reserved space on ext2 filesystem. Modify data journaling
/// mode on ext3 filesystem (uses journaling resources). NOTE: ext2
/// honors fsuid when checking for resource overrides, so you can
/// override using fsuid too. Override size restrictions on IPC message
/// queues. Allow more than 64hz interrupts from the real-time clock.
/// Override max number of consoles on console allocation. Override max
/// number of keymaps. Control memory reclaim behavior.
SystemResource = linux_raw_sys::general::CAP_SYS_RESOURCE,
/// Allow manipulation of system clock. Allow `irix_stime` on mips. Allow
/// setting the real-time clock.
SystemTime = linux_raw_sys::general::CAP_SYS_TIME,
/// Allow configuration of tty devices. Allow `vhangup` of tty.
SystemTTYConfig = linux_raw_sys::general::CAP_SYS_TTY_CONFIG,
/// Allow the privileged aspects of `mknod`.
MakeNode = linux_raw_sys::general::CAP_MKNOD,
/// Allow taking of leases on files.
Lease = linux_raw_sys::general::CAP_LEASE,
/// Allow writing the audit log via unicast netlink socket.
AuditWrite = linux_raw_sys::general::CAP_AUDIT_WRITE,
/// Allow configuration of audit via unicast netlink socket.
AuditControl = linux_raw_sys::general::CAP_AUDIT_CONTROL,
/// Set or remove capabilities on files. Map `uid=0` into a child user
/// namespace.
SetFileCapabilities = linux_raw_sys::general::CAP_SETFCAP,
/// Override MAC access. The base kernel enforces no MAC policy. An LSM may
/// enforce a MAC policy, and if it does and it chooses to implement
/// capability based overrides of that policy, this is the capability
/// it should use to do so.
MACOverride = linux_raw_sys::general::CAP_MAC_OVERRIDE,
/// Allow MAC configuration or state changes. The base kernel requires no
/// MAC configuration. An LSM may enforce a MAC policy, and if it does
/// and it chooses to implement capability based
/// checks on modifications to that policy or the data required to maintain
/// it, this is the capability it should use to do so.
MACAdmin = linux_raw_sys::general::CAP_MAC_ADMIN,
/// Allow configuring the kernel's `syslog` (`printk` behaviour).
SystemLog = linux_raw_sys::general::CAP_SYSLOG,
/// Allow triggering something that will wake the system.
WakeAlarm = linux_raw_sys::general::CAP_WAKE_ALARM,
/// Allow preventing system suspends.
BlockSuspend = linux_raw_sys::general::CAP_BLOCK_SUSPEND,
/// Allow reading the audit log via multicast netlink socket.
AuditRead = linux_raw_sys::general::CAP_AUDIT_READ,
/// Allow system performance and observability privileged operations using
/// `perf_events`, `i915_perf` and other kernel subsystems.
PerformanceMonitoring = linux_raw_sys::general::CAP_PERFMON,
/// This capability allows the following BPF operations:
/// - Creating all types of BPF maps
/// - Advanced verifier features
/// - Indirect variable access
/// - Bounded loops
/// - BPF to BPF function calls
/// - Scalar precision tracking
/// - Larger complexity limits
/// - Dead code elimination
/// - And potentially other features
/// - Loading BPF Type Format (BTF) data
/// - Retrieve `xlated` and JITed code of BPF programs
/// - Use `bpf_spin_lock` helper
///
/// [`Capability::PerformanceMonitoring`] relaxes the verifier checks
/// further:
/// - BPF progs can use of pointer-to-integer conversions
/// - speculation attack hardening measures are bypassed
/// - `bpf_probe_read` to read arbitrary kernel memory is allowed
/// - `bpf_trace_printk` to print kernel memory is allowed
///
/// [`Capability::SystemAdmin`] is required to use bpf_probe_write_user.
///
/// [`Capability::SystemAdmin`] is required to iterate system-wide loaded
/// programs, maps, links, and BTFs, and convert their IDs to file
/// descriptors.
///
/// [`Capability::PerformanceMonitoring`] and
/// [`Capability::BerkeleyPacketFilters`] are required to load tracing
/// programs. [`Capability::NetAdmin`] and
/// [`Capability::BerkeleyPacketFilters`] are required to load
/// networking programs.
BerkeleyPacketFilters = linux_raw_sys::general::CAP_BPF,
/// Allow checkpoint/restore related operations. Allow PID selection during
/// `clone3`. Allow writing to `ns_last_pid`.
CheckpointRestore = linux_raw_sys::general::CAP_CHECKPOINT_RESTORE,
}
/// Check if the specified capability is in the calling thread's capability
/// bounding set.
///
/// # References
/// - [`prctl(PR_CAPBSET_READ,...)`]
///
#[inline]
pub fn capability_is_in_bounding_set(capability: Capability) -> io::Result<bool> {
unsafe { prctl_2args(PR_CAPBSET_READ, capability as usize as *mut _) }.map(|r| r != 0)
}
const PR_CAPBSET_DROP: c_int = 24;
/// If the calling thread has the [`Capability::SetPermittedCapabilities`]
/// capability within its user namespace, then drop the specified capability
/// from the thread's capability bounding set.
///
/// # References
/// - [`prctl(PR_CAPBSET_DROP,...)`]
///
#[inline]
pub fn remove_capability_from_bounding_set(capability: Capability) -> io::Result<()> {
unsafe { prctl_2args(PR_CAPBSET_DROP, capability as usize as *mut _) }.map(|_r| ())
}
//
// PR_GET_SECUREBITS/PR_SET_SECUREBITS
//
const PR_GET_SECUREBITS: c_int = 27;
bitflags! {
/// `SECBIT_*`.
#[repr(transparent)]
#[derive(Copy, Clone, Eq, PartialEq, Hash, Debug)]
pub struct CapabilitiesSecureBits: u32 {
/// If this bit is set, then the kernel does not grant capabilities
/// when a `set-user-ID-root` program is executed, or when a process
/// with an effective or real UID of 0 calls `execve`.
const NO_ROOT = 1_u32 << 0;
/// Set [`NO_ROOT`] irreversibly.
const NO_ROOT_LOCKED = 1_u32 << 1;
/// Setting this flag stops the kernel from adjusting the process'
/// permitted, effective, and ambient capability sets when the thread's
/// effective and filesystem UIDs are switched between zero and nonzero
/// values.
const NO_SETUID_FIXUP = 1_u32 << 2;
/// Set [`NO_SETUID_FIXUP`] irreversibly.
const NO_SETUID_FIXUP_LOCKED = 1_u32 << 3;
/// Setting this flag allows a thread that has one or more 0 UIDs to
/// retain capabilities in its permitted set when it switches all of
/// its UIDs to nonzero values.
const KEEP_CAPS = 1_u32 << 4;
/// Set [`KEEP_CAPS`] irreversibly.
const KEEP_CAPS_LOCKED = 1_u32 << 5;
/// Setting this flag disallows raising ambient capabilities via the
/// `prctl`'s `PR_CAP_AMBIENT_RAISE` operation.
const NO_CAP_AMBIENT_RAISE = 1_u32 << 6;
/// Set [`NO_CAP_AMBIENT_RAISE`] irreversibly.
const NO_CAP_AMBIENT_RAISE_LOCKED = 1_u32 << 7;
const _ = !0;
}
}
/// Get the `securebits` flags of the calling thread.
///
/// # References
/// - [`prctl(PR_GET_SECUREBITS,...)`]
///
#[inline]
pub fn capabilities_secure_bits() -> io::Result<CapabilitiesSecureBits> {
let r = unsafe { prctl_1arg(PR_GET_SECUREBITS)? } as c_uint;
CapabilitiesSecureBits::from_bits(r).ok_or(io::Errno::RANGE)
}
const PR_SET_SECUREBITS: c_int = 28;
/// Set the `securebits` flags of the calling thread.
///
/// # References
/// - [`prctl(PR_SET_SECUREBITS,...)`]
///
#[inline]
pub fn set_capabilities_secure_bits(bits: CapabilitiesSecureBits) -> io::Result<()> {
unsafe { prctl_2args(PR_SET_SECUREBITS, bits.bits() as usize as *mut _) }.map(|_r| ())
}
//
// PR_GET_TIMERSLACK/PR_SET_TIMERSLACK
//
const PR_GET_TIMERSLACK: c_int = 30;
/// Get the `current` timer slack value of the calling thread.
///
/// # References
/// - [`prctl(PR_GET_TIMERSLACK,...)`]
///
#[inline]
pub fn current_timer_slack() -> io::Result<u64> {
unsafe { prctl_1arg(PR_GET_TIMERSLACK) }.map(|r| r as u64)
}
const PR_SET_TIMERSLACK: c_int = 29;
/// Sets the `current` timer slack value for the calling thread.
///
/// # References
/// - [`prctl(PR_SET_TIMERSLACK,...)`]
///
#[inline]
pub fn set_current_timer_slack(value: Option<NonZeroU64>) -> io::Result<()> {
let value = usize::try_from(value.map_or(0, NonZeroU64::get)).map_err(|_r| io::Errno::RANGE)?;
unsafe { prctl_2args(PR_SET_TIMERSLACK, value as *mut _) }.map(|_r| ())
}
//
// PR_GET_NO_NEW_PRIVS/PR_SET_NO_NEW_PRIVS
//
const PR_GET_NO_NEW_PRIVS: c_int = 39;
/// Get the value of the `no_new_privs` attribute for the calling thread.
///
/// # References
/// - [`prctl(PR_GET_NO_NEW_PRIVS,...)`]
///
#[inline]
pub fn no_new_privs() -> io::Result<bool> {
unsafe { prctl_1arg(PR_GET_NO_NEW_PRIVS) }.map(|r| r != 0)
}
const PR_SET_NO_NEW_PRIVS: c_int = 38;
/// Set the calling thread's `no_new_privs` attribute.
///
/// # References
/// - [`prctl(PR_SET_NO_NEW_PRIVS,...)`]
///
#[inline]
pub fn set_no_new_privs(no_new_privs: bool) -> io::Result<()> {
unsafe { prctl_2args(PR_SET_NO_NEW_PRIVS, usize::from(no_new_privs) as *mut _) }.map(|_r| ())
}
//
// PR_GET_TID_ADDRESS
//
const PR_GET_TID_ADDRESS: c_int = 40;
/// Get the `clear_child_tid` address set by `set_tid_address`
/// and `clone`'s `CLONE_CHILD_CLEARTID` flag.
///
/// # References
/// - [`prctl(PR_GET_TID_ADDRESS,...)`]
///
#[inline]
pub fn get_clear_child_tid_address() -> io::Result<Option<NonNull<c_void>>> {
unsafe { prctl_get_at_arg2_optional::<*mut c_void>(PR_GET_TID_ADDRESS) }.map(NonNull::new)
}
//
// PR_GET_THP_DISABLE/PR_SET_THP_DISABLE
//
const PR_GET_THP_DISABLE: c_int = 42;
/// Get the current setting of the `THP disable` flag for the calling thread.
///
/// # References
/// - [`prctl(PR_GET_THP_DISABLE,...)`]
///
#[inline]
pub fn transparent_huge_pages_are_disabled() -> io::Result<bool> {
unsafe { prctl_1arg(PR_GET_THP_DISABLE) }.map(|r| r != 0)
}
const PR_SET_THP_DISABLE: c_int = 41;
/// Set the state of the `THP disable` flag for the calling thread.
///
/// # References
/// - [`prctl(PR_SET_THP_DISABLE,...)`]
///
#[inline]
pub fn disable_transparent_huge_pages(thp_disable: bool) -> io::Result<()> {
unsafe { prctl_2args(PR_SET_THP_DISABLE, usize::from(thp_disable) as *mut _) }.map(|_r| ())
}
//
// PR_CAP_AMBIENT
//
const PR_CAP_AMBIENT: c_int = 47;
const PR_CAP_AMBIENT_IS_SET: usize = 1;
/// Check if the specified capability is in the ambient set.
///
/// # References
/// - [`prctl(PR_CAP_AMBIENT,PR_CAP_AMBIENT_IS_SET,...)`]
///
/// [`prctl(PR_CAP_AMBIENT,PR_CAP_AMBIENT_IS_SET,...)`]: https://man7.org/linux/man-pages/man2/prctl.2.html
#[inline]
pub fn capability_is_in_ambient_set(capability: Capability) -> io::Result<bool> {
let cap = capability as usize as *mut _;
unsafe { prctl_3args(PR_CAP_AMBIENT, PR_CAP_AMBIENT_IS_SET as *mut _, cap) }.map(|r| r != 0)
}
const PR_CAP_AMBIENT_CLEAR_ALL: usize = 4;
/// Remove all capabilities from the ambient set.
///
/// # References
/// - [`prctl(PR_CAP_AMBIENT,PR_CAP_AMBIENT_CLEAR_ALL,...)`]
///
/// [`prctl(PR_CAP_AMBIENT,PR_CAP_AMBIENT_CLEAR_ALL,...)`]: https://man7.org/linux/man-pages/man2/prctl.2.html
#[inline]
pub fn clear_ambient_capability_set() -> io::Result<()> {
unsafe { prctl_2args(PR_CAP_AMBIENT, PR_CAP_AMBIENT_CLEAR_ALL as *mut _) }.map(|_r| ())
}
const PR_CAP_AMBIENT_RAISE: usize = 2;
const PR_CAP_AMBIENT_LOWER: usize = 3;
/// Add or remove the specified capability to the ambient set.
///
/// # References
/// - [`prctl(PR_CAP_AMBIENT,...)`]
///
#[inline]
pub fn configure_capability_in_ambient_set(capability: Capability, enable: bool) -> io::Result<()> {
let sub_operation = if enable {
PR_CAP_AMBIENT_RAISE
} else {
PR_CAP_AMBIENT_LOWER
};
let cap = capability as usize as *mut _;
unsafe { prctl_3args(PR_CAP_AMBIENT, sub_operation as *mut _, cap) }.map(|_r| ())
}
//
// PR_SVE_GET_VL/PR_SVE_SET_VL
//
const PR_SVE_GET_VL: c_int = 51;
const PR_SVE_VL_LEN_MASK: u32 = 0xffff;
const PR_SVE_VL_INHERIT: u32 = 1_u32 << 17;
/// Scalable Vector Extension vector length configuration.
#[derive(Copy, Clone, Debug, Eq, PartialEq)]
pub struct SVEVectorLengthConfig {
/// Vector length in bytes.
pub vector_length_in_bytes: u32,
/// Vector length inherited across `execve`.
pub vector_length_inherited_across_execve: bool,
}
/// Get the thread's current SVE vector length configuration.
///
/// # References
/// - [`prctl(PR_SVE_GET_VL,...)`]
///
#[inline]
pub fn sve_vector_length_configuration() -> io::Result<SVEVectorLengthConfig> {
let bits = unsafe { prctl_1arg(PR_SVE_GET_VL)? } as c_uint;
Ok(SVEVectorLengthConfig {
vector_length_in_bytes: bits & PR_SVE_VL_LEN_MASK,
vector_length_inherited_across_execve: (bits & PR_SVE_VL_INHERIT) != 0,
})
}
const PR_SVE_SET_VL: c_int = 50;
const PR_SVE_SET_VL_ONEXEC: u32 = 1_u32 << 18;
/// Configure the thread's vector length of Scalable Vector Extension.
///
/// # References
/// - [`prctl(PR_SVE_SET_VL,...)`]
///
/// # Safety
///
/// Please ensure the conditions necessary to safely call this function,
/// as detailed in the references above.
///
#[inline]
pub unsafe fn set_sve_vector_length_configuration(
vector_length_in_bytes: usize,
vector_length_inherited_across_execve: bool,
defer_change_to_next_execve: bool,
) -> io::Result<()> {
let vector_length_in_bytes =
u32::try_from(vector_length_in_bytes).map_err(|_r| io::Errno::RANGE)?;
let mut bits = vector_length_in_bytes & PR_SVE_VL_LEN_MASK;
if vector_length_inherited_across_execve {
bits |= PR_SVE_VL_INHERIT;
}
if defer_change_to_next_execve {
bits |= PR_SVE_SET_VL_ONEXEC;
}
prctl_2args(PR_SVE_SET_VL, bits as usize as *mut _).map(|_r| ())
}
//
// PR_PAC_RESET_KEYS
//
const PR_PAC_RESET_KEYS: c_int = 54;
/// Securely reset the thread's pointer authentication keys to fresh random
/// values generated by the kernel.
///
/// # References
/// - [`prctl(PR_PAC_RESET_KEYS,...)`]
///
/// # Safety
///
/// Please ensure the conditions necessary to safely call this function,
/// as detailed in the references above.
///
#[inline]
pub unsafe fn reset_pointer_authentication_keys(
keys: Option<PointerAuthenticationKeys>,
) -> io::Result<()> {
let keys = keys.as_ref().map_or(0_u32, PointerAuthenticationKeys::bits);
prctl_2args(PR_PAC_RESET_KEYS, keys as usize as *mut _).map(|_r| ())
}
//
// PR_GET_TAGGED_ADDR_CTRL/PR_SET_TAGGED_ADDR_CTRL
//
const PR_GET_TAGGED_ADDR_CTRL: c_int = 56;
const PR_MTE_TAG_SHIFT: u32 = 3;
const PR_MTE_TAG_MASK: u32 = 0xffff_u32 << PR_MTE_TAG_SHIFT;
bitflags! {
/// Zero means addresses that are passed for the purpose of being
/// dereferenced by the kernel must be untagged.
#[repr(transparent)]
#[derive(Copy, Clone, Eq, PartialEq, Hash, Debug)]
pub struct TaggedAddressMode: u32 {
/// Addresses that are passed for the purpose of being dereferenced by
/// the kernel may be tagged.
const ENABLED = 1_u32 << 0;
/// Synchronous tag check fault mode.
const TCF_SYNC = 1_u32 << 1;
/// Asynchronous tag check fault mode.
const TCF_ASYNC = 1_u32 << 2;
const _ = !0;
}
}
/// Get the current tagged address mode for the calling thread.
///
/// # References
/// - [`prctl(PR_GET_TAGGED_ADDR_CTRL,...)`]
///
#[inline]
pub fn current_tagged_address_mode() -> io::Result<(Option<TaggedAddressMode>, u32)> {
let r = unsafe { prctl_1arg(PR_GET_TAGGED_ADDR_CTRL)? } as c_uint;
let mode = r & 0b111_u32;
let mte_tag = (r & PR_MTE_TAG_MASK) >> PR_MTE_TAG_SHIFT;
Ok((TaggedAddressMode::from_bits(mode), mte_tag))
}
const PR_SET_TAGGED_ADDR_CTRL: c_int = 55;
/// Controls support for passing tagged user-space addresses to the kernel.
///
/// # References
/// - [`prctl(PR_SET_TAGGED_ADDR_CTRL,...)`]
///
/// # Safety
///
/// Please ensure the conditions necessary to safely call this function, as
/// detailed in the references above.
///
#[inline]
pub unsafe fn set_current_tagged_address_mode(
mode: Option<TaggedAddressMode>,
mte_tag: u32,
) -> io::Result<()> {
let config = mode.as_ref().map_or(0_u32, TaggedAddressMode::bits)
| ((mte_tag << PR_MTE_TAG_SHIFT) & PR_MTE_TAG_MASK);
prctl_2args(PR_SET_TAGGED_ADDR_CTRL, config as usize as *mut _).map(|_r| ())
}
//
// PR_SET_SYSCALL_USER_DISPATCH
//
const PR_SET_SYSCALL_USER_DISPATCH: c_int = 59;
const PR_SYS_DISPATCH_OFF: usize = 0;
/// Disable Syscall User Dispatch mechanism.
///
/// # References
/// - [`prctl(PR_SET_SYSCALL_USER_DISPATCH,PR_SYS_DISPATCH_OFF,...)`]
///
/// # Safety
///
/// Please ensure the conditions necessary to safely call this function, as
/// detailed in the references above.
///
/// [`prctl(PR_SET_SYSCALL_USER_DISPATCH,PR_SYS_DISPATCH_OFF,...)`]: https://man7.org/linux/man-pages/man2/prctl.2.html
#[inline]
pub unsafe fn disable_syscall_user_dispatch() -> io::Result<()> {
prctl_2args(PR_SET_SYSCALL_USER_DISPATCH, PR_SYS_DISPATCH_OFF as *mut _).map(|_r| ())
}
const PR_SYS_DISPATCH_ON: usize = 1;
/// Allow system calls to be executed.
const SYSCALL_DISPATCH_FILTER_ALLOW: u8 = 0;
/// Block system calls from executing.
const SYSCALL_DISPATCH_FILTER_BLOCK: u8 = 1;
/// Value of the fast switch flag controlling system calls user dispatch
/// mechanism without the need to issue a syscall.
#[derive(Copy, Clone, Debug, Eq, PartialEq)]
#[repr(u8)]
pub enum SysCallUserDispatchFastSwitch {
/// System calls are allowed to execute.
Allow = SYSCALL_DISPATCH_FILTER_ALLOW,
/// System calls are blocked from executing.
Block = SYSCALL_DISPATCH_FILTER_BLOCK,
}
impl TryFrom<u8> for SysCallUserDispatchFastSwitch {
type Error = io::Errno;
fn try_from(value: u8) -> Result<Self, Self::Error> {
match value {
SYSCALL_DISPATCH_FILTER_ALLOW => Ok(Self::Allow),
SYSCALL_DISPATCH_FILTER_BLOCK => Ok(Self::Block),
_ => Err(io::Errno::RANGE),
}
}
}
/// Enable Syscall User Dispatch mechanism.
///
/// # References
/// - [`prctl(PR_SET_SYSCALL_USER_DISPATCH,PR_SYS_DISPATCH_ON,...)`]
///
/// # Safety
///
/// Please ensure the conditions necessary to safely call this function, as
/// detailed in the references above.
///
/// [`prctl(PR_SET_SYSCALL_USER_DISPATCH,PR_SYS_DISPATCH_ON,...)`]: https://man7.org/linux/man-pages/man2/prctl.2.html
#[inline]
pub unsafe fn enable_syscall_user_dispatch(
always_allowed_region: &[u8],
fast_switch_flag: &AtomicU8,
) -> io::Result<()> {
syscalls::prctl(
PR_SET_SYSCALL_USER_DISPATCH,
PR_SYS_DISPATCH_ON as *mut _,
always_allowed_region.as_ptr() as *mut _,
always_allowed_region.len() as *mut _,
as_ptr(fast_switch_flag) as *mut _,
)
.map(|_r| ())
}
//
// PR_SCHED_CORE
//
const PR_SCHED_CORE: c_int = 62;
const PR_SCHED_CORE_GET: usize = 0;
const PR_SCHED_CORE_SCOPE_THREAD: u32 = 0;
const PR_SCHED_CORE_SCOPE_THREAD_GROUP: u32 = 1;
const PR_SCHED_CORE_SCOPE_PROCESS_GROUP: u32 = 2;
/// `PR_SCHED_CORE_SCOPE_*`.
#[derive(Copy, Clone, Debug, Eq, PartialEq)]
#[repr(u32)]
pub enum CoreSchedulingScope {
/// Operation will be performed for the thread.
Thread = PR_SCHED_CORE_SCOPE_THREAD,
/// Operation will be performed for all tasks in the task group of the
/// process.
ThreadGroup = PR_SCHED_CORE_SCOPE_THREAD_GROUP,
/// Operation will be performed for all processes in the process group.
ProcessGroup = PR_SCHED_CORE_SCOPE_PROCESS_GROUP,
}
impl TryFrom<u32> for CoreSchedulingScope {
type Error = io::Errno;
fn try_from(value: u32) -> Result<Self, Self::Error> {
match value {
PR_SCHED_CORE_SCOPE_THREAD => Ok(Self::Thread),
PR_SCHED_CORE_SCOPE_THREAD_GROUP => Ok(Self::ThreadGroup),
PR_SCHED_CORE_SCOPE_PROCESS_GROUP => Ok(Self::ProcessGroup),
_ => Err(io::Errno::RANGE),
}
}
}
/// Get core scheduling cookie of a process.
///
/// # References
/// - [`prctl(PR_SCHED_CORE,PR_SCHED_CORE_GET,...)`]
///
/// [`prctl(PR_SCHED_CORE,PR_SCHED_CORE_GET,...)`]: https://www.kernel.org/doc/html/v5.18/admin-guide/hw-vuln/core-scheduling.html
#[inline]
pub fn core_scheduling_cookie(pid: Pid, scope: CoreSchedulingScope) -> io::Result<u64> {
let mut value: MaybeUninit<u64> = MaybeUninit::uninit();
unsafe {
syscalls::prctl(
PR_SCHED_CORE,
PR_SCHED_CORE_GET as *mut _,
pid.as_raw_nonzero().get() as usize as *mut _,
scope as usize as *mut _,
value.as_mut_ptr().cast(),
)?;
Ok(value.assume_init())
}
}
const PR_SCHED_CORE_CREATE: usize = 1;
/// Create unique core scheduling cookie.
///
/// # References
/// - [`prctl(PR_SCHED_CORE,PR_SCHED_CORE_CREATE,...)`]
///
/// [`prctl(PR_SCHED_CORE,PR_SCHED_CORE_CREATE,...)`]: https://www.kernel.org/doc/html/v5.18/admin-guide/hw-vuln/core-scheduling.html
#[inline]
pub fn create_core_scheduling_cookie(pid: Pid, scope: CoreSchedulingScope) -> io::Result<()> {
unsafe {
syscalls::prctl(
PR_SCHED_CORE,
PR_SCHED_CORE_CREATE as *mut _,
pid.as_raw_nonzero().get() as usize as *mut _,
scope as usize as *mut _,
ptr::null_mut(),
)
.map(|_r| ())
}
}
const PR_SCHED_CORE_SHARE_TO: usize = 2;
/// Push core scheduling cookie to a process.
///
/// # References
/// - [`prctl(PR_SCHED_CORE,PR_SCHED_CORE_SHARE_TO,...)`]
///
/// [`prctl(PR_SCHED_CORE,PR_SCHED_CORE_SHARE_TO,...)`]: https://www.kernel.org/doc/html/v5.18/admin-guide/hw-vuln/core-scheduling.html
#[inline]
pub fn push_core_scheduling_cookie(pid: Pid, scope: CoreSchedulingScope) -> io::Result<()> {
unsafe {
syscalls::prctl(
PR_SCHED_CORE,
PR_SCHED_CORE_SHARE_TO as *mut _,
pid.as_raw_nonzero().get() as usize as *mut _,
scope as usize as *mut _,
ptr::null_mut(),
)
.map(|_r| ())
}
}
const PR_SCHED_CORE_SHARE_FROM: usize = 3;
/// Pull core scheduling cookie from a process.
///
/// # References
/// - [`prctl(PR_SCHED_CORE,PR_SCHED_CORE_SHARE_FROM,...)`]
///
/// [`prctl(PR_SCHED_CORE,PR_SCHED_CORE_SHARE_FROM,...)`]: https://www.kernel.org/doc/html/v5.18/admin-guide/hw-vuln/core-scheduling.html
#[inline]
pub fn pull_core_scheduling_cookie(pid: Pid, scope: CoreSchedulingScope) -> io::Result<()> {
unsafe {
syscalls::prctl(
PR_SCHED_CORE,
PR_SCHED_CORE_SHARE_FROM as *mut _,
pid.as_raw_nonzero().get() as usize as *mut _,
scope as usize as *mut _,
ptr::null_mut(),
)
.map(|_r| ())
}
}