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use crate::errno::Errno;
use crate::sys::signal::Signal;
use crate::unistd::Pid;
use crate::Result;
use cfg_if::cfg_if;
use libc::{self, c_int};
use std::ptr;
pub type RequestType = c_int;
cfg_if! {
if #[cfg(any(freebsdlike, apple_targets, target_os = "openbsd"))] {
#[doc(hidden)]
pub type AddressType = *mut ::libc::c_char;
} else {
#[doc(hidden)]
pub type AddressType = *mut ::libc::c_void;
}
}
libc_enum! {
#[repr(i32)]
/// Ptrace Request enum defining the action to be taken.
#[non_exhaustive]
pub enum Request {
PT_TRACE_ME,
PT_READ_I,
PT_READ_D,
#[cfg(apple_targets)]
PT_READ_U,
PT_WRITE_I,
PT_WRITE_D,
#[cfg(apple_targets)]
PT_WRITE_U,
PT_CONTINUE,
PT_KILL,
#[cfg(any(any(freebsdlike, apple_targets),
all(target_os = "openbsd", target_arch = "x86_64"),
all(target_os = "netbsd", any(target_arch = "x86_64",
target_arch = "powerpc"))))]
PT_STEP,
PT_ATTACH,
PT_DETACH,
#[cfg(apple_targets)]
PT_SIGEXC,
#[cfg(apple_targets)]
PT_THUPDATE,
#[cfg(apple_targets)]
PT_ATTACHEXC
}
}
unsafe fn ptrace_other(
request: Request,
pid: Pid,
addr: AddressType,
data: c_int,
) -> Result<c_int> {
unsafe {
Errno::result(libc::ptrace(
request as RequestType,
libc::pid_t::from(pid),
addr,
data,
))
.map(|_| 0)
}
}
/// Sets the process as traceable, as with `ptrace(PT_TRACEME, ...)`
///
/// Indicates that this process is to be traced by its parent.
/// This is the only ptrace request to be issued by the tracee.
pub fn traceme() -> Result<()> {
unsafe {
ptrace_other(Request::PT_TRACE_ME, Pid::from_raw(0), ptr::null_mut(), 0)
.map(drop)
}
}
/// Attach to a running process, as with `ptrace(PT_ATTACH, ...)`
///
/// Attaches to the process specified by `pid`, making it a tracee of the calling process.
pub fn attach(pid: Pid) -> Result<()> {
unsafe {
ptrace_other(Request::PT_ATTACH, pid, ptr::null_mut(), 0).map(drop)
}
}
/// Detaches the current running process, as with `ptrace(PT_DETACH, ...)`
///
/// Detaches from the process specified by `pid` allowing it to run freely, optionally delivering a
/// signal specified by `sig`.
pub fn detach<T: Into<Option<Signal>>>(pid: Pid, sig: T) -> Result<()> {
let data = match sig.into() {
Some(s) => s as c_int,
None => 0,
};
unsafe {
ptrace_other(Request::PT_DETACH, pid, ptr::null_mut(), data).map(drop)
}
}
/// Restart the stopped tracee process, as with `ptrace(PTRACE_CONT, ...)`
///
/// Continues the execution of the process with PID `pid`, optionally
/// delivering a signal specified by `sig`.
pub fn cont<T: Into<Option<Signal>>>(pid: Pid, sig: T) -> Result<()> {
let data = match sig.into() {
Some(s) => s as c_int,
None => 0,
};
unsafe {
// Ignore the useless return value
ptrace_other(Request::PT_CONTINUE, pid, 1 as AddressType, data)
.map(drop)
}
}
/// Issues a kill request as with `ptrace(PT_KILL, ...)`
///
/// This request is equivalent to `ptrace(PT_CONTINUE, ..., SIGKILL);`
pub fn kill(pid: Pid) -> Result<()> {
unsafe {
ptrace_other(Request::PT_KILL, pid, 0 as AddressType, 0).map(drop)
}
}
/// Move the stopped tracee process forward by a single step as with
/// `ptrace(PT_STEP, ...)`
///
/// Advances the execution of the process with PID `pid` by a single step optionally delivering a
/// signal specified by `sig`.
///
/// # Example
/// ```rust
/// use nix::sys::ptrace::step;
/// use nix::unistd::Pid;
/// use nix::sys::signal::Signal;
/// use nix::sys::wait::*;
/// // If a process changes state to the stopped state because of a SIGUSR1
/// // signal, this will step the process forward and forward the user
/// // signal to the stopped process
/// match waitpid(Pid::from_raw(-1), None) {
/// Ok(WaitStatus::Stopped(pid, Signal::SIGUSR1)) => {
/// let _ = step(pid, Signal::SIGUSR1);
/// }
/// _ => {},
/// }
/// ```
#[cfg(any(
any(freebsdlike, apple_targets),
all(target_os = "openbsd", target_arch = "x86_64"),
all(
target_os = "netbsd",
any(target_arch = "x86_64", target_arch = "powerpc")
)
))]
pub fn step<T: Into<Option<Signal>>>(pid: Pid, sig: T) -> Result<()> {
let data = match sig.into() {
Some(s) => s as c_int,
None => 0,
};
unsafe {
ptrace_other(Request::PT_STEP, pid, ptr::null_mut(), data).map(drop)
}
}
/// Reads a word from a processes memory at the given address
// Technically, ptrace doesn't dereference the pointer. It passes it directly
// to the kernel.
#[allow(clippy::not_unsafe_ptr_arg_deref)]
pub fn read(pid: Pid, addr: AddressType) -> Result<c_int> {
unsafe {
// Traditionally there was a difference between reading data or
// instruction memory but not in modern systems.
ptrace_other(Request::PT_READ_D, pid, addr, 0)
}
}
/// Writes a word into the processes memory at the given address
// Technically, ptrace doesn't dereference the pointer. It passes it directly
// to the kernel.
#[allow(clippy::not_unsafe_ptr_arg_deref)]
pub fn write(pid: Pid, addr: AddressType, data: c_int) -> Result<()> {
unsafe { ptrace_other(Request::PT_WRITE_D, pid, addr, data).map(drop) }
}