From f4090d46de6e7b10d817aa67add21c37e26f4c9a Mon Sep 17 00:00:00 2001
From: Andreas Kling <kling@serenityos.org>
Date: Sun, 27 Jun 2021 10:46:47 +0200
Subject: [PATCH] Kernel: Don't kmalloc() for small (<=1024) dbgputstr()
 syscalls

---
 Kernel/Syscalls/debug.cpp | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/Kernel/Syscalls/debug.cpp b/Kernel/Syscalls/debug.cpp
index 9f17265148..38bf5591f9 100644
--- a/Kernel/Syscalls/debug.cpp
+++ b/Kernel/Syscalls/debug.cpp
@@ -28,10 +28,18 @@ KResultOr<size_t> Process::sys$dbgputstr(Userspace<const u8*> characters, size_t
     if (size == 0)
         return 0;
 
+    if (size <= 1024) {
+        char buffer[1024];
+        if (!copy_from_user(buffer, characters, size))
+            return EFAULT;
+        dbgputstr(buffer, size);
+        return size;
+    }
+
     auto result = try_copy_kstring_from_user(reinterpret_cast<char const*>(characters.unsafe_userspace_ptr()), size);
     if (result.is_error())
         return result.error();
-    dbgputstr(reinterpret_cast<const char*>(result.value()->characters()), size);
+    dbgputstr(result.value()->characters(), size);
     return size;
 }