Starting to write custom clib wrapper

src/clibwrap/mod.rs

@@ -0,0 +1,11 @@
+use std::ffi::c_long;
+
+pub mod ptrace;
+
+type Pid = i32;
+
+#[derive(Debug, thiserror::Error)]
+#[error("Some kind of error when calling into C code: return code {error_code}")]
+pub struct CError {
+	error_code: c_long,
+}

src/clibwrap/ptrace.rs

@@ -0,0 +1,31 @@
+use crate::clibwrap::{CError, Pid};
+use std::ffi::{c_long, c_void};
+
+#[allow(non_camel_case_types)]
+#[repr(u32)]
+enum PTraceRequest {
+	PTRACE_CONT = 7,
+	PTRACE_SINGLESTEP = 9,
+}
+
+unsafe extern "C" {
+	fn ptrace(request: PTraceRequest, pid: Pid, addr: *mut c_void, data: *mut c_void) -> c_long;
+}
+
+pub fn cont(pid: Pid) -> Result<(), CError> {
+	let return_code = unsafe { ptrace(PTraceRequest::PTRACE_CONT, pid, 0 as _, 0 as _) };
+	if return_code == 0 {
+		Ok(())
+	} else {
+		Err(CError { error_code: return_code })
+	}
+}
+
+pub fn single_step(pid: Pid) -> Result<(), CError> {
+	let return_code = unsafe { ptrace(PTraceRequest::PTRACE_SINGLESTEP, pid, 0 as _, 0 as _) };
+	if return_code == 0 {
+		Ok(())
+	} else {
+		Err(CError { error_code: return_code })
+	}
+}

src/debug_target/mod.rs

@@ -1,6 +1,7 @@
 mod stopped_target;
 mod running_target;
 
+use crate::clibwrap;
 use nix::unistd::Pid;
 pub use running_target::*;
 pub use stopped_target::*;
@@ -18,6 +19,9 @@ pub enum DebugError {
 	#[error(transparent)]
 	PTraceError(#[from] PTraceError),
 
+	#[error(transparent)]
+	CustomPTraceError(#[from] clibwrap::CError),
+
 	#[error(transparent)]
 	WaitError(#[from] WaitError),
 

src/debug_target/stopped_target.rs

@@ -1,3 +1,4 @@
+use crate::clibwrap;
 use crate::debug_target::{DebugError, PTraceError, RunningTarget, WaitError};
 use crate::syscall_info::{syscall_info, SyscallInfo, SyscallInfoError};
 use libc::{c_long, user_regs_struct};
@@ -42,7 +43,7 @@ impl StoppedTarget {
 		if self.on_breakpoint()? {
 			self.breakpoint_remove_and_rewind()?;
 		}
-		nix::sys::ptrace::cont(self.pid, None).map_err(PTraceError)?;
+		clibwrap::ptrace::cont(self.pid.as_raw())?;
 		Ok(self.to_running())
 	}
 
@@ -50,7 +51,7 @@ impl StoppedTarget {
 		if self.on_breakpoint()? {
 			self.breakpoint_remove_and_rewind()?;
 		}
-		nix::sys::ptrace::step(self.pid, None).map_err(PTraceError)?;
+		clibwrap::ptrace::single_step(self.pid.as_raw())?;
 		Ok(self.to_running())
 	}
 

src/main.rs

@@ -1,5 +1,6 @@
 mod debug_target;
 mod syscall_info;
+mod clibwrap;
 
 use crate::debug_target::{ExitedTarget, StoppedTarget};
 use color_eyre::eyre::eyre;