LadybirdBrowser/ladybird
1
1
Fork 0
mirror of https://github.com/LadybirdBrowser/ladybird.git synced 2024-09-20 01:37:39 +03:00
Code Issues Packages Projects Releases Wiki Activity

Kernel: Quickly reject userspace addresses in kernel_region_from_vaddr()

Browse Source 
This avoids taking and releasing the MM lock just to reject an address
that we can tell from just looking at it that it won't ever be in the
kernel regions tree.
This commit is contained in:
Andreas Kling 2022-01-28 15:02:45 +01:00
parent 145eeb57ab
commit 5092813a45
Notes: sideshowbarker 2024-07-17 20:04:07 +09:00 
Author: https://github.com/awesomekling
Commit: https://github.com/SerenityOS/serenity/commit/5092813a45d
1 changed files with 3 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
Kernel/Memory/MemoryManager.cpp
View File

@ -645,6 +645,9 @@ UNMAP_AFTER_INIT void MemoryManager::initialize(u32 cpu)
Region* MemoryManager::kernel_region_from_vaddr(VirtualAddress vaddr)
{
if (is_user_address(vaddr))
return nullptr;
SpinlockLocker lock(s_mm_lock);
auto* region = MM.m_kernel_regions.find_largest_not_above(vaddr.get());
if (!region || !region->contains(vaddr))