From be06661d1a687201615203dcc1d42eb8d7337da9 Mon Sep 17 00:00:00 2001
From: Francisco Giordano <frangio.1@gmail.com>
Date: Sun, 9 Jun 2019 18:54:48 -0300
Subject: [PATCH] allow signal injection in ptrace::syscall and ptrace::detach

---
 src/sys/ptrace/bsd.rs   | 13 ++++++++++---
 src/sys/ptrace/linux.rs | 22 ++++++++++++++++------
 test/sys/test_wait.rs   |  2 +-
 3 files changed, 27 insertions(+), 10 deletions(-)

diff --git a/src/sys/ptrace/bsd.rs b/src/sys/ptrace/bsd.rs
index 7797d10647..5528115304 100644
--- a/src/sys/ptrace/bsd.rs
+++ b/src/sys/ptrace/bsd.rs
@@ -84,9 +84,16 @@ pub fn attach(pid: Pid) -> Result<()> {
 
 /// Detaches the current running process, as with `ptrace(PT_DETACH, ...)`
 ///
-/// Detaches from the process specified in pid allowing it to run freely
-pub fn detach(pid: Pid) -> Result<()> {
-    unsafe { ptrace_other(Request::PT_DETACH, pid, ptr::null_mut(), 0).map(drop) }
+/// Detaches from the process specified in 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, ...)`
diff --git a/src/sys/ptrace/linux.rs b/src/sys/ptrace/linux.rs
index df15e66527..20b203cd60 100644
--- a/src/sys/ptrace/linux.rs
+++ b/src/sys/ptrace/linux.rs
@@ -290,14 +290,19 @@ pub fn traceme() -> Result<()> {
 
 /// Ask for next syscall, as with `ptrace(PTRACE_SYSCALL, ...)`
 ///
-/// Arranges for the tracee to be stopped at the next entry to or exit from a system call.
-pub fn syscall(pid: Pid) -> Result<()> {
+/// Arranges for the tracee to be stopped at the next entry to or exit from a system call,
+/// optionally delivering a signal specified by `sig`.
+pub fn syscall<T: Into<Option<Signal>>>(pid: Pid, sig: T) -> Result<()> {
+    let data = match sig.into() {
+        Some(s) => s as i32 as *mut c_void,
+        None => ptr::null_mut(),
+    };
     unsafe {
         ptrace_other(
             Request::PTRACE_SYSCALL,
             pid,
             ptr::null_mut(),
-            ptr::null_mut(),
+            data,
         ).map(drop) // ignore the useless return value
     }
 }
@@ -318,14 +323,19 @@ pub fn attach(pid: Pid) -> Result<()> {
 
 /// Detaches the current running process, as with `ptrace(PTRACE_DETACH, ...)`
 ///
-/// Detaches from the process specified in pid allowing it to run freely
-pub fn detach(pid: Pid) -> Result<()> {
+/// Detaches from the process specified in 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 i32 as *mut c_void,
+        None => ptr::null_mut(),
+    };
     unsafe {
         ptrace_other(
             Request::PTRACE_DETACH,
             pid,
             ptr::null_mut(),
-            ptr::null_mut()
+            data
         ).map(drop)
     }
 }
diff --git a/test/sys/test_wait.rs b/test/sys/test_wait.rs
index d07d82f0d9..c17598f2c0 100644
--- a/test/sys/test_wait.rs
+++ b/test/sys/test_wait.rs
@@ -82,7 +82,7 @@ mod ptrace {
         assert!(ptrace::setoptions(child, Options::PTRACE_O_TRACESYSGOOD | Options::PTRACE_O_TRACEEXIT).is_ok());
 
         // First, stop on the next system call, which will be exit()
-        assert!(ptrace::syscall(child).is_ok());
+        assert!(ptrace::syscall(child, None).is_ok());
         assert_eq!(waitpid(child, None), Ok(WaitStatus::PtraceSyscall(child)));
         // Then get the ptrace event for the process exiting
         assert!(ptrace::cont(child, None).is_ok());