From b356ddc3aafb1cc5f3dead438840bcec5e91e645 Mon Sep 17 00:00:00 2001
From: jD91mZM2 <me@krake.one>
Date: Mon, 1 Jul 2019 12:32:22 +0200
Subject: [PATCH] WIP(ptrace): Add test for singlesteps

---
 Cargo.lock  |  7 +++++
 Cargo.toml  |  1 +
 src/main.rs | 80 ++++++++++++++++++++++++++++++++++++++++++++++++++++-
 3 files changed, 87 insertions(+), 1 deletion(-)

diff --git a/Cargo.lock b/Cargo.lock
index b6d66d6..bc6a0c8 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -4,6 +4,7 @@
 name = "acid"
 version = "0.1.0"
 dependencies = [
+ "redox_syscall 0.1.54 (git+https://gitlab.redox-os.org/jD91mZM2/syscall.git?branch=ptrace)",
  "x86 0.7.2 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -201,6 +202,11 @@ dependencies = [
  "bitflags 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "redox_syscall"
+version = "0.1.54"
+source = "git+https://gitlab.redox-os.org/jD91mZM2/syscall.git?branch=ptrace#a7aff4b60d537e6f336ff7e8affe8801a92c20f0"
+
 [[package]]
 name = "rustc-serialize"
 version = "0.3.24"
@@ -284,6 +290,7 @@ dependencies = [
 "checksum rand_core 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "1961a422c4d189dfb50ffa9320bf1f2a9bd54ecb92792fb9477f99a1045f3372"
 "checksum rand_core 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "0905b6b7079ec73b314d4c748701f6931eb79fd97c668caa3f1899b22b32c6db"
 "checksum raw-cpuid 2.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "13b844e4049605ff38fed943f5c7b2c691fad68d9d5bf074d2720554c4e48246"
+"checksum redox_syscall 0.1.54 (git+https://gitlab.redox-os.org/jD91mZM2/syscall.git?branch=ptrace)" = "<none>"
 "checksum rustc-serialize 0.3.24 (registry+https://github.com/rust-lang/crates.io-index)" = "dcf128d1287d2ea9d80910b5f1120d0b8eede3fbf1abe91c40d39ea7d51e6fda"
 "checksum serde 0.6.15 (registry+https://github.com/rust-lang/crates.io-index)" = "c97b18e9e53de541f11e497357d6c5eaeb39f0cb9c8734e274abe4935f6991fa"
 "checksum serde_json 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)" = "b5aaee47e038bf9552d30380d3973fff2593ee0a76d81ad4c581f267cdcadf36"
diff --git a/Cargo.toml b/Cargo.toml
index f57ab6d..bccefe0 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -5,3 +5,4 @@ authors = ["Jeremy Soller <jackpot51@gmail.com>"]
 
 [dependencies]
 x86 = "0.7"
+redox_syscall = { git = "https://gitlab.redox-os.org/jD91mZM2/syscall.git", branch = "ptrace" }
diff --git a/src/main.rs b/src/main.rs
index 7e7ef7d..56aed2c 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,5 +1,5 @@
 //!Acid testing program
-#![feature(thread_local)]
+#![feature(thread_local, asm)]
 
 extern crate x86;
 
@@ -51,6 +51,83 @@ fn page_fault_test() -> Result<(), String> {
     Ok(())
 }
 
+fn ptrace() -> Result<(), String> {
+    use std::{
+        fs::File,
+        io::prelude::*,
+        os::{raw::c_int, unix::io::{AsRawFd, FromRawFd}}
+    };
+
+    let pid = unsafe { syscall::clone(0).map_err(|e| format!("clone failed: {}", e))? };
+    if pid == 0 {
+        unsafe {
+            asm!("
+                mov rax, 20 // GETPID
+                syscall
+
+                mov rdi, rax
+
+                mov rax, 37 // SYS_KILL
+                mov rsi, 19 // SIGSTOP
+                syscall
+
+                // Start of body
+                mov rax, 1
+                push rax
+                mov rax, 2
+                push rax
+                mov rax, 3
+                pop rax
+                pop rax
+                // End of body
+
+                mov rax, 1 // SYS_EXIT
+                mov rdi, 0
+                syscall
+                "
+                : : : : "intel", "volatile"
+            );
+        }
+    }
+
+    // Wait until child is ready to be traced
+    let mut status = 0;
+    syscall::waitpid(pid, &mut status, syscall::WUNTRACED).map_err(|e| format!("waitpid failed: {}", e))?;
+
+    // Stop & attach process + get handle to registers
+    let mut proc_file = File::open(format!("proc:{}/trace", pid)).map_err(|e| format!("open failed: {}", e))?;
+    let mut regs_file = unsafe {
+        File::from_raw_fd(
+            syscall::dup(proc_file.as_raw_fd() as usize, b"regs/int")
+                .map_err(|e| format!("dup failed: {}", e))? as c_int
+        )
+    };
+
+    // Schedule restart of process when resumed
+    syscall::kill(pid, syscall::SIGCONT).map_err(|e| format!("kill failed: {}", e))?;
+
+    let mut next = move |op| -> Result<syscall::IntRegisters, String> {
+        proc_file.write(&[op]).map_err(|e| format!("ptrace operation failed: {}", e))?;
+
+        let mut regs: syscall::IntRegisters = syscall::IntRegisters::default();
+        regs_file.read(&mut regs).map_err(|e| format!("reading registers failed: {}", e))?;
+        Ok(regs)
+    };
+
+    // Step out of syscall down to the next instruction
+    let _ = next(syscall::PTRACE_SINGLESTEP)?;
+    assert_eq!(next(syscall::PTRACE_SINGLESTEP)?.rax, 1);
+    assert_eq!(next(syscall::PTRACE_SINGLESTEP)?.rax, 2);
+    assert_eq!(next(syscall::PTRACE_SINGLESTEP)?.rax, 2);
+    assert_eq!(next(syscall::PTRACE_SINGLESTEP)?.rax, 3);
+    assert_eq!(next(syscall::PTRACE_SINGLESTEP)?.rax, 2);
+    assert_eq!(next(syscall::PTRACE_SINGLESTEP)?.rax, 1);
+
+    assert_eq!(next(syscall::PTRACE_SYSCALL)?.rax, syscall::SYS_EXIT);
+
+    Ok(())
+}
+
 fn switch_test() -> Result<(), String> {
     use std::thread;
     use x86::time::rdtscp;
@@ -181,6 +258,7 @@ fn main() {
     let mut tests: BTreeMap<&'static str, fn() -> Result<(), String>> = BTreeMap::new();
     tests.insert("create_test", create_test);
     tests.insert("page_fault", page_fault_test);
+    tests.insert("ptrace", ptrace);
     tests.insert("switch", switch_test);
     tests.insert("tcp_fin", tcp_fin_test);
     tests.insert("thread", thread_test);