From 29f8da76d725d38998854d2fb7c8e0cc9498407d Mon Sep 17 00:00:00 2001
From: Trung Nguyen <trungnt282910@gmail.com>
Date: Fri, 9 Jun 2023 20:21:35 +1000
Subject: [PATCH] strace: Add mutex type

Added a dedicated mutex type handler that can print mutex status
flags while still showing the mutex address.

Change-Id: Ie028e5c0a336063a4c03a4f9adf955ffa6911837
Reviewed-on: https://review.haiku-os.org/c/haiku/+/6557
Reviewed-by: waddlesplash <waddlesplash@gmail.com>
---
 src/bin/debug/strace/Jamfile       |  1 +
 src/bin/debug/strace/TypeHandler.h |  3 +-
 src/bin/debug/strace/mutex.cpp     | 83 ++++++++++++++++++++++++++++++
 src/bin/debug/strace/strace.cpp    |  2 +
 4 files changed, 88 insertions(+), 1 deletion(-)
 create mode 100644 src/bin/debug/strace/mutex.cpp

diff --git a/src/bin/debug/strace/Jamfile b/src/bin/debug/strace/Jamfile
index 382f60853d..cf557990a5 100644
--- a/src/bin/debug/strace/Jamfile
+++ b/src/bin/debug/strace/Jamfile
@@ -24,6 +24,7 @@ local straceSources =
 	exec.cpp
 	fcntl.cpp
 	ioctl.cpp
+	mutex.cpp
 	network.cpp
 	signals.cpp
 ;
diff --git a/src/bin/debug/strace/TypeHandler.h b/src/bin/debug/strace/TypeHandler.h
index 6e803e8db0..4943d5df94 100644
--- a/src/bin/debug/strace/TypeHandler.h
+++ b/src/bin/debug/strace/TypeHandler.h
@@ -63,9 +63,10 @@ public:
 	string GetParameterValue(Context &c, Parameter *, const void *);
 	string GetReturnValue(Context &, uint64 value);
 
-private:
+protected:
 	string RenderValue(Context &, unsigned int value) const;
 
+private:
 	const FlagsList &fList;
 };
 
diff --git a/src/bin/debug/strace/mutex.cpp b/src/bin/debug/strace/mutex.cpp
new file mode 100644
index 0000000000..519e80fec9
--- /dev/null
+++ b/src/bin/debug/strace/mutex.cpp
@@ -0,0 +1,83 @@
+/*
+ * Copyright 2023, Trung Nguyen, trungnt282910@gmail.com.
+ * Distributed under the terms of the MIT License.
+ */
+
+
+#include <string.h>
+
+#include <user_mutex_defs.h>
+
+#include "strace.h"
+#include "Context.h"
+#include "MemoryReader.h"
+#include "TypeHandler.h"
+
+
+#define FLAG_INFO_ENTRY(name) \
+	{ name, #name }
+
+static const FlagsTypeHandler::FlagInfo kMutexFlagsInfo[] = {
+    FLAG_INFO_ENTRY(B_USER_MUTEX_LOCKED),
+    FLAG_INFO_ENTRY(B_USER_MUTEX_WAITING),
+    FLAG_INFO_ENTRY(B_USER_MUTEX_DISABLED),
+
+	{ 0, NULL }
+};
+
+static FlagsTypeHandler::FlagsList kMutexFlags;
+
+
+class MutexTypeHandler : public FlagsTypeHandler {
+public:
+    MutexTypeHandler()
+        :
+        FlagsTypeHandler(kMutexFlags)
+    {
+    }
+
+	string GetParameterValue(Context &context, Parameter *param,
+		const void *address)
+	{
+        void *data = *(void **)address;
+
+		if (context.GetContents(Context::POINTER_VALUES)) {
+            int32 value, bytesRead;
+            status_t err = context.Reader().Read(data, &value, sizeof(value), bytesRead);
+            if (err != B_OK)
+                return context.FormatPointer(data);
+
+            string r = context.FormatPointer(data);
+            r += " [";
+            r += RenderValue(context, (unsigned int)value);
+            r += "]";
+            return r;
+        }
+
+		return context.FormatPointer(data);
+	}
+
+	string GetReturnValue(Context &context, uint64 value)
+	{
+		return context.FormatPointer((void *)value);
+	}
+};
+
+
+void
+patch_mutex()
+{
+    for (int i = 0; kMutexFlagsInfo[i].name != NULL; i++) {
+        kMutexFlags.push_back(kMutexFlagsInfo[i]);
+    }
+
+    Syscall *mutex_lock = get_syscall("_kern_mutex_lock");
+    mutex_lock->GetParameter("mutex")->SetHandler(new MutexTypeHandler());
+
+    Syscall *mutex_unlock = get_syscall("_kern_mutex_unblock");
+    mutex_unlock->GetParameter("mutex")->SetHandler(new MutexTypeHandler());
+
+    Syscall *mutex_switch_lock = get_syscall("_kern_mutex_switch_lock");
+    mutex_switch_lock->GetParameter("fromMutex")->SetHandler(new MutexTypeHandler());
+    mutex_switch_lock->GetParameter("toMutex")->SetHandler(new MutexTypeHandler());
+}
diff --git a/src/bin/debug/strace/strace.cpp b/src/bin/debug/strace/strace.cpp
index dd9b4de90a..876ca6ec5b 100644
--- a/src/bin/debug/strace/strace.cpp
+++ b/src/bin/debug/strace/strace.cpp
@@ -233,6 +233,7 @@ patch_syscalls()
 	extern void patch_exec();
 	extern void patch_fcntl();
 	extern void patch_ioctl();
+	extern void patch_mutex();
 	extern void patch_network();
 
 	for (size_t i = 0; i < sSyscallVector.size(); i++) {
@@ -250,6 +251,7 @@ patch_syscalls()
 	patch_exec();
 	patch_fcntl();
 	patch_ioctl();
+	patch_mutex();
 	patch_network();
 }