From c0ffff7e8807f528395c96659f98d3e3eec15e97 Mon Sep 17 00:00:00 2001
From: Dan Klishch <danilklishch@gmail.com>
Date: Mon, 13 Nov 2023 22:10:20 -0500
Subject: [PATCH] AK: Ban JsonValue from the kernel and remove ifdef guards

JsonValue can store JsonObject which uses DS for keys, so it is not safe
to use it in the kernel even with the double/String guards.
---
 AK/JsonValue.h                              | 55 ++++-----------------
 Kernel/FileSystem/ProcFS/ProcessExposed.cpp |  1 -
 2 files changed, 9 insertions(+), 47 deletions(-)

diff --git a/AK/JsonValue.h b/AK/JsonValue.h
index 0a02b42371..85b6b9f73d 100644
--- a/AK/JsonValue.h
+++ b/AK/JsonValue.h
@@ -6,14 +6,15 @@
 
 #pragma once
 
+#ifdef KERNEL
+#    error "JsonValue does not propagate allocation failures, so it is not safe to use in the kernel."
+#endif
+
+#include <AK/DeprecatedString.h>
 #include <AK/Forward.h>
 #include <AK/Optional.h>
 #include <AK/StringBuilder.h>
 
-#ifndef KERNEL
-#    include <AK/DeprecatedString.h>
-#endif
-
 namespace AK {
 
 class JsonValue {
@@ -24,9 +25,7 @@ public:
         UnsignedInt32,
         Int64,
         UnsignedInt64,
-#if !defined(KERNEL)
         Double,
-#endif
         Bool,
         String,
         Array,
@@ -51,13 +50,9 @@ public:
     JsonValue(long long);
     JsonValue(long long unsigned);
 
-#if !defined(KERNEL)
     JsonValue(double);
-#endif
     JsonValue(char const*);
-#ifndef KERNEL
     JsonValue(DeprecatedString const&);
-#endif
     JsonValue(StringView);
 
     template<typename T>
@@ -83,7 +78,6 @@ public:
     template<typename Builder>
     void serialize(Builder&) const;
 
-#ifndef KERNEL
     DeprecatedString as_string_or(DeprecatedString const& alternative) const
     {
         if (is_string())
@@ -97,25 +91,16 @@ public:
             return as_string();
         return serialized<StringBuilder>();
     }
-#endif
 
-    int to_int(int default_value = 0) const
-    {
-        return to_i32(default_value);
-    }
+    int to_int(int default_value = 0) const { return to_i32(default_value); }
     i32 to_i32(i32 default_value = 0) const { return to_number<i32>(default_value); }
     i64 to_i64(i64 default_value = 0) const { return to_number<i64>(default_value); }
 
     unsigned to_uint(unsigned default_value = 0) const { return to_u32(default_value); }
     u32 to_u32(u32 default_value = 0) const { return to_number<u32>(default_value); }
     u64 to_u64(u64 default_value = 0) const { return to_number<u64>(default_value); }
-#if !defined(KERNEL)
-    float to_float(float default_value = 0) const
-    {
-        return to_number<float>(default_value);
-    }
+    float to_float(float default_value = 0) const { return to_number<float>(default_value); }
     double to_double(double default_value = 0) const { return to_number<double>(default_value); }
-#endif
 
     FlatPtr to_addr(FlatPtr default_value = 0) const
     {
@@ -163,13 +148,11 @@ public:
         return m_value.as_bool;
     }
 
-#ifndef KERNEL
     DeprecatedString as_string() const
     {
         VERIFY(is_string());
         return *m_value.as_string;
     }
-#endif
 
     JsonObject& as_object()
     {
@@ -195,13 +178,11 @@ public:
         return *m_value.as_array;
     }
 
-#if !defined(KERNEL)
     double as_double() const
     {
         VERIFY(is_double());
         return m_value.as_double;
     }
-#endif
 
     Type type() const
     {
@@ -215,16 +196,8 @@ public:
     bool is_u32() const { return m_type == Type::UnsignedInt32; }
     bool is_i64() const { return m_type == Type::Int64; }
     bool is_u64() const { return m_type == Type::UnsignedInt64; }
-#if !defined(KERNEL)
-    bool is_double() const
-    {
-        return m_type == Type::Double;
-    }
-#endif
-    bool is_array() const
-    {
-        return m_type == Type::Array;
-    }
+    bool is_double() const { return m_type == Type::Double; }
+    bool is_array() const { return m_type == Type::Array; }
     bool is_object() const { return m_type == Type::Object; }
     bool is_number() const
     {
@@ -233,9 +206,7 @@ public:
         case Type::UnsignedInt32:
         case Type::Int64:
         case Type::UnsignedInt64:
-#if !defined(KERNEL)
         case Type::Double:
-#endif
             return true;
         default:
             return false;
@@ -245,10 +216,8 @@ public:
     template<typename T>
     T to_number(T default_value = 0) const
     {
-#if !defined(KERNEL)
         if (is_double())
             return (T)as_double();
-#endif
         if (type() == Type::Int32)
             return (T)as_i32();
         if (type() == Type::UnsignedInt32)
@@ -305,14 +274,10 @@ private:
     Type m_type { Type::Null };
 
     union {
-#ifndef KERNEL
         StringImpl* as_string { nullptr };
-#endif
         JsonArray* as_array;
         JsonObject* as_object;
-#if !defined(KERNEL)
         double as_double;
-#endif
         i32 as_i32;
         u32 as_u32;
         i64 as_i64;
@@ -321,7 +286,6 @@ private:
     } m_value;
 };
 
-#ifndef KERNEL
 template<>
 struct Formatter<JsonValue> : Formatter<StringView> {
     ErrorOr<void> format(FormatBuilder& builder, JsonValue const& value)
@@ -329,7 +293,6 @@ struct Formatter<JsonValue> : Formatter<StringView> {
         return Formatter<StringView>::format(builder, value.to_deprecated_string());
     }
 };
-#endif
 
 }
 
diff --git a/Kernel/FileSystem/ProcFS/ProcessExposed.cpp b/Kernel/FileSystem/ProcFS/ProcessExposed.cpp
index 389d6cc7e4..de929a7c14 100644
--- a/Kernel/FileSystem/ProcFS/ProcessExposed.cpp
+++ b/Kernel/FileSystem/ProcFS/ProcessExposed.cpp
@@ -6,7 +6,6 @@
 
 #include <AK/JsonArraySerializer.h>
 #include <AK/JsonObjectSerializer.h>
-#include <AK/JsonValue.h>
 #include <Kernel/Devices/TTY/TTY.h>
 #include <Kernel/FileSystem/Custody.h>
 #include <Kernel/FileSystem/ProcFS/Inode.h>