linux-kernel - [PATCHv3 09/12] dmapool: simplify freeing

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20230103191551.3254778-10-kbusch@meta.com>
Date:   Tue, 3 Jan 2023 11:15:48 -0800
From:   Keith Busch <kbusch@...a.com>
To:     <linux-mm@...ck.org>, <linux-kernel@...r.kernel.org>,
        Matthew Wilcox <willy@...radead.org>,
        Christoph Hellwig <hch@....de>
CC:     Tony Battersby <tonyb@...ernetics.com>,
        Kernel Team <kernel-team@...a.com>,
        Keith Busch <kbusch@...nel.org>
Subject: [PATCHv3 09/12] dmapool: simplify freeing

From: Keith Busch <kbusch@...nel.org>

The actions for busy and not busy are mostly the same, so combine these
and remove the unnecessary function. Also, the pool is about to be freed
so there's no need to poison the page data since we only check for
poison on alloc, which can't be done on a freed pool.

Signed-off-by: Keith Busch <kbusch@...nel.org>
---
 mm/dmapool.c | 26 +++++++-------------------
 1 file changed, 7 insertions(+), 19 deletions(-)

diff --git a/mm/dmapool.c b/mm/dmapool.c
index 6862b4e763891..4dab48e7e0d75 100644
--- a/mm/dmapool.c
+++ b/mm/dmapool.c
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /*
- * DMA Pool allocator
+* DMA Pool allocator
  *
  * Copyright 2001 David Brownell
  * Copyright 2007 Intel Corporation
@@ -241,18 +241,6 @@ static inline bool is_page_busy(struct dma_page *page)
 	return page->in_use != 0;
 }
 
-static void pool_free_page(struct dma_pool *pool, struct dma_page *page)
-{
-	dma_addr_t dma = page->dma;
-
-#ifdef	DMAPOOL_DEBUG
-	memset(page->vaddr, POOL_POISON_FREED, pool->allocation);
-#endif
-	dma_free_coherent(pool->dev, pool->allocation, page->vaddr, dma);
-	list_del(&page->page_list);
-	kfree(page);
-}
-
 /**
  * dma_pool_destroy - destroys a pool of dma memory blocks.
  * @pool: dma pool that will be destroyed
@@ -280,14 +268,14 @@ void dma_pool_destroy(struct dma_pool *pool)
 	mutex_unlock(&pools_reg_lock);
 
 	list_for_each_entry_safe(page, tmp, &pool->page_list, page_list) {
-		if (is_page_busy(page)) {
+		if (!is_page_busy(page))
+			dma_free_coherent(pool->dev, pool->allocation,
+					  page->vaddr, page->dma);
+		else
 			dev_err(pool->dev, "%s %s, %p busy\n", __func__,
 				pool->name, page->vaddr);
-			/* leak the still-in-use consistent memory */
-			list_del(&page->page_list);
-			kfree(page);
-		} else
-			pool_free_page(pool, page);
+		list_del(&page->page_list);
+		kfree(page);
 	}
 
 	kfree(pool);
-- 
2.30.2