From 0786d50332a868ba2e794efdd7cc7f052a356872 Mon Sep 17 00:00:00 2001
From: Augustin Cavalier <waddlesplash@gmail.com>
Date: Sat, 20 Jun 2020 14:54:49 -0400
Subject: [PATCH] DMAResource: Validate that alignment <= block_size.

The code here cannot handle the case where alignment > block_size,
so anything calling Init() with these parameters is invalid.

Fixes #15902 (nvme_disk was long since adjusted, so this is a defense
against code being written in the future.)
---
 src/system/kernel/device_manager/dma_resources.cpp | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/system/kernel/device_manager/dma_resources.cpp b/src/system/kernel/device_manager/dma_resources.cpp
index dfbaf80479..99d0d3a858 100644
--- a/src/system/kernel/device_manager/dma_resources.cpp
+++ b/src/system/kernel/device_manager/dma_resources.cpp
@@ -158,6 +158,8 @@ status_t
 DMAResource::Init(const dma_restrictions& restrictions,
 	generic_size_t blockSize, uint32 bufferCount, uint32 bounceBufferCount)
 {
+	ASSERT(restrictions.alignment <= blockSize);
+
 	fRestrictions = restrictions;
 	fBlockSize = blockSize == 0 ? 1 : blockSize;
 	fBufferCount = bufferCount;