From b4c560d4b8a3d0baf2cc941e5ff85e9b1ea6beef Mon Sep 17 00:00:00 2001
From: Bastian Buck <59334447+bstnbuck@users.noreply.github.com>
Date: Sat, 25 May 2024 23:46:43 +0200
Subject: [PATCH] os: fix debugger_present() for non Windows OSes (#21573)

---
 vlib/os/debugger_darwin.c.v  | 32 ++++++++++++++++++++++++++++----
 vlib/os/debugger_freebsd.c.v | 32 ++++++++++++++++++++++++++++----
 vlib/os/debugger_linux.c.v   | 32 ++++++++++++++++++++++++++++----
 3 files changed, 84 insertions(+), 12 deletions(-)

diff --git a/vlib/os/debugger_darwin.c.v b/vlib/os/debugger_darwin.c.v
index 0a0f8f7ee5..44dd22c481 100644
--- a/vlib/os/debugger_darwin.c.v
+++ b/vlib/os/debugger_darwin.c.v
@@ -6,12 +6,36 @@ module os
 fn C.ptrace(int, u32, voidptr, int) int
 
 // debugger_present returns a bool indicating if the process is being debugged
-@[inline]
 pub fn debugger_present() bool {
-	// check if the parent could trace its process,
-	// if not a debugger must be present
 	$if macos {
-		return C.ptrace(C.PT_TRACE_ME, 0, voidptr(1), 0) == -1
+		// check if a child process could trace its parent process,
+		// if not a debugger must be present
+		pid := fork()
+		if pid == 0 {
+			ppid := getppid()
+			if C.ptrace(C.PT_TRACE_ME, ppid, unsafe { nil }, 0) == 0 {
+				C.waitpid(ppid, 0, 0)
+
+				// detach ptrace, otherwise further checks would indicate a debugger is present (ptrace is the Debugger then)
+				C.ptrace(C.PT_DETACH, ppid, 0, 0)
+
+				// no external debugger
+				exit(0)
+			} else {
+				// an error occured, a external debugger must be present
+				exit(1)
+			}
+		} else {
+			mut status := 0
+			// wait until the child process dies
+			C.waitpid(pid, &status, 0)
+			// check the exit code of the child process check
+			if C.WEXITSTATUS(status) == 0 {
+				return false
+			} else {
+				return true
+			}
+		}
 	}
 	return false
 }
diff --git a/vlib/os/debugger_freebsd.c.v b/vlib/os/debugger_freebsd.c.v
index 2e61d25b5f..60232c9207 100644
--- a/vlib/os/debugger_freebsd.c.v
+++ b/vlib/os/debugger_freebsd.c.v
@@ -5,12 +5,36 @@ module os
 fn C.ptrace(int, u32, voidptr, int) int
 
 // debugger_present returns a bool indicating if the process is being debugged
-@[inline]
 pub fn debugger_present() bool {
-	// check if the parent could trace its process,
-	// if not a debugger must be present
 	$if freebsd {
-		return C.ptrace(C.PT_TRACE_ME, 0, voidptr(1), 0) == -1
+		// check if a child process could trace its parent process,
+		// if not a debugger must be present
+		pid := fork()
+		if pid == 0 {
+			ppid := getppid()
+			if C.ptrace(C.PT_TRACE_ME, ppid, unsafe { nil }, 0) == 0 {
+				C.waitpid(ppid, 0, 0)
+
+				// detach ptrace, otherwise further checks would indicate a debugger is present (ptrace is the Debugger then)
+				C.ptrace(C.PT_DETACH, ppid, 0, 0)
+
+				// no external debugger
+				exit(0)
+			} else {
+				// an error occured, a external debugger must be present
+				exit(1)
+			}
+		} else {
+			mut status := 0
+			// wait until the child process dies
+			C.waitpid(pid, &status, 0)
+			// check the exit code of the child process check
+			if C.WEXITSTATUS(status) == 0 {
+				return false
+			} else {
+				return true
+			}
+		}
 	}
 	return false
 }
diff --git a/vlib/os/debugger_linux.c.v b/vlib/os/debugger_linux.c.v
index 90ea3fdc19..63f75e369a 100644
--- a/vlib/os/debugger_linux.c.v
+++ b/vlib/os/debugger_linux.c.v
@@ -5,16 +5,40 @@ module os
 fn C.ptrace(u32, u32, voidptr, voidptr) u64
 
 // debugger_present returns a bool indicating if the process is being debugged
-@[inline]
 pub fn debugger_present() bool {
 	$if cross ? {
 		return false
 	}
 	$if !cross ? {
-		// check if the parent could trace its process,
-		// if not a debugger must be present
 		$if linux {
-			return C.ptrace(C.PTRACE_TRACEME, 0, 1, 0) == -1
+			// check if a child process could trace its parent process,
+			// if not a debugger must be present
+			pid := fork()
+			if pid == 0 {
+				ppid := getppid()
+				if C.ptrace(C.PTRACE_ATTACH, ppid, 0, 0) == 0 {
+					C.waitpid(ppid, 0, 0)
+
+					// detach ptrace, otherwise further checks would indicate a debugger is present (ptrace is the Debugger then)
+					C.ptrace(C.PTRACE_DETACH, ppid, 0, 0)
+
+					// no external debugger
+					exit(0)
+				} else {
+					// an error occured, a external debugger must be present
+					exit(1)
+				}
+			} else {
+				mut status := 0
+				// wait until the child process dies
+				C.waitpid(pid, &status, 0)
+				// check the exit code of the child process check
+				if C.WEXITSTATUS(status) == 0 {
+					return false
+				} else {
+					return true
+				}
+			}
 		}
 	}
 	return false