From 75df45d709445c8a74ea8b7be5c60ef3fe852a90 Mon Sep 17 00:00:00 2001
From: Sergey Bugaev <bugaevc@gmail.com>
Date: Wed, 12 Jun 2019 16:25:28 +0300
Subject: [PATCH] Kernel: Fix comparing StringViews with strcmp().

StringView character buffer is not guaranteed to be null-terminated;
in particular it will not be null-terminated when making a substring.
This means that the buffer can not be used with C functions that expect
a null-terminated string. Instead, StringView provides a convinient
operator == for comparing it with Strings and C stirngs, so use that.

This fixes /proc/self/... resolution failures in ProcFS, since the name
("self") passed to ProcFSInode::lookup() would not be null-terminated.
---
 Kernel/FileSystem/Ext2FileSystem.cpp | 4 ++--
 Kernel/FileSystem/ProcFS.cpp         | 6 +++---
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/Kernel/FileSystem/Ext2FileSystem.cpp b/Kernel/FileSystem/Ext2FileSystem.cpp
index 0f85b40892..3ad2c9b306 100644
--- a/Kernel/FileSystem/Ext2FileSystem.cpp
+++ b/Kernel/FileSystem/Ext2FileSystem.cpp
@@ -767,7 +767,7 @@ KResult Ext2FSInode::add_child(InodeIdentifier child_id, const StringView& name,
     Vector<FS::DirectoryEntry> entries;
     bool name_already_exists = false;
     traverse_as_directory([&](auto& entry) {
-        if (!strcmp(entry.name, name.characters())) {
+        if (name == entry.name) {
             name_already_exists = true;
             return false;
         }
@@ -812,7 +812,7 @@ KResult Ext2FSInode::remove_child(const StringView& name)
 
     Vector<FS::DirectoryEntry> entries;
     traverse_as_directory([&](auto& entry) {
-        if (strcmp(entry.name, name.characters()) != 0)
+        if (name != entry.name)
             entries.append(entry);
         return true;
     });
diff --git a/Kernel/FileSystem/ProcFS.cpp b/Kernel/FileSystem/ProcFS.cpp
index aef44fcbe5..e197fd1c92 100644
--- a/Kernel/FileSystem/ProcFS.cpp
+++ b/Kernel/FileSystem/ProcFS.cpp
@@ -966,7 +966,7 @@ InodeIdentifier ProcFSInode::lookup(StringView name)
             if (entry.name == nullptr)
                 continue;
             if (entry.proc_file_type > __FI_Root_Start && entry.proc_file_type < __FI_Root_End) {
-                if (!strcmp(entry.name, name.characters())) {
+                if (name == entry.name) {
                     return to_identifier(fsid(), PDI_Root, 0, (ProcFileType)entry.proc_file_type);
                 }
             }
@@ -988,7 +988,7 @@ InodeIdentifier ProcFSInode::lookup(StringView name)
     if (proc_file_type == FI_Root_sys) {
         for (int i = 0; i < fs().m_sys_entries.size(); ++i) {
             auto& entry = fs().m_sys_entries[i];
-            if (!strcmp(entry.name, name.characters()))
+            if (name == entry.name)
                 return sys_var_to_identifier(fsid(), i);
         }
         return {};
@@ -1005,7 +1005,7 @@ InodeIdentifier ProcFSInode::lookup(StringView name)
                     continue;
                 if (entry.name == nullptr)
                     continue;
-                if (!strcmp(entry.name, name.characters())) {
+                if (name == entry.name) {
                     return to_identifier(fsid(), PDI_PID, to_pid(identifier()), (ProcFileType)entry.proc_file_type);
                 }
             }