From e380142853f2468a76a48a8c0036b1c46f977da9 Mon Sep 17 00:00:00 2001
From: Andreas Kling <awesomekling@gmail.com>
Date: Sat, 11 Jan 2020 10:36:54 +0100
Subject: [PATCH] Kernel: Pass a parameter struct to rename()

---
 Kernel/Process.cpp       | 17 +++++++++++------
 Kernel/Process.h         |  2 +-
 Kernel/Syscall.h         |  5 +++++
 Libraries/LibC/stdio.cpp |  7 ++++++-
 4 files changed, 23 insertions(+), 8 deletions(-)

diff --git a/Kernel/Process.cpp b/Kernel/Process.cpp
index 4b6c062ed4..9bdd497d6c 100644
--- a/Kernel/Process.cpp
+++ b/Kernel/Process.cpp
@@ -3476,14 +3476,19 @@ int Process::sys$donate(int tid)
     return 0;
 }
 
-int Process::sys$rename(const char* oldpath, const char* newpath)
+int Process::sys$rename(const Syscall::SC_rename_params* user_params)
 {
-    SmapDisabler disabler;
-    if (!validate_read_str(oldpath))
+    if (!validate_read_typed(user_params))
         return -EFAULT;
-    if (!validate_read_str(newpath))
-        return -EFAULT;
-    return VFS::the().rename(StringView(oldpath), StringView(newpath), current_directory());
+    Syscall::SC_rename_params params;
+    copy_from_user(&params, user_params);
+    auto old_path = get_syscall_path_argument(params.old_path.characters, params.old_path.length);
+    if (old_path.is_error())
+        return old_path.error();
+    auto new_path = get_syscall_path_argument(params.new_path.characters, params.new_path.length);
+    if (new_path.is_error())
+        return new_path.error();
+    return VFS::the().rename(old_path.value(), new_path.value(), current_directory());
 }
 
 int Process::sys$ftruncate(int fd, off_t length)
diff --git a/Kernel/Process.h b/Kernel/Process.h
index dc21932cb3..50f36ee6e4 100644
--- a/Kernel/Process.h
+++ b/Kernel/Process.h
@@ -204,7 +204,7 @@ public:
     int sys$detach_thread(int tid);
     int sys$set_thread_name(int tid, const char* buffer, int buffer_size);
     int sys$get_thread_name(int tid, char* buffer, int buffer_size);
-    int sys$rename(const char* oldpath, const char* newpath);
+    int sys$rename(const Syscall::SC_rename_params*);
     int sys$systrace(pid_t);
     int sys$mknod(const Syscall::SC_mknod_params*);
     int sys$create_shared_buffer(int, void** buffer);
diff --git a/Kernel/Syscall.h b/Kernel/Syscall.h
index b2e2c39d8f..57899c3883 100644
--- a/Kernel/Syscall.h
+++ b/Kernel/Syscall.h
@@ -350,6 +350,11 @@ struct SC_symlink_params {
     StringArgument linkpath;
 };
 
+struct SC_rename_params {
+    StringArgument old_path;
+    StringArgument new_path;
+};
+
 void initialize();
 int sync();
 
diff --git a/Libraries/LibC/stdio.cpp b/Libraries/LibC/stdio.cpp
index 5f93aba2bb..5a28d90325 100644
--- a/Libraries/LibC/stdio.cpp
+++ b/Libraries/LibC/stdio.cpp
@@ -510,7 +510,12 @@ int fclose(FILE* stream)
 
 int rename(const char* oldpath, const char* newpath)
 {
-    int rc = syscall(SC_rename, oldpath, newpath);
+    if (!oldpath || !newpath) {
+        errno = EFAULT;
+        return -1;
+    }
+    Syscall::SC_rename_params params { { oldpath, strlen(oldpath) }, { newpath, strlen(newpath) } };
+    int rc = syscall(SC_rename, &params);
     __RETURN_WITH_ERRNO(rc, rc, -1);
 }