Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754275Ab2KENk0 (ORCPT ); Mon, 5 Nov 2012 08:40:26 -0500 Received: from mail-bk0-f46.google.com ([209.85.214.46]:41574 "EHLO mail-bk0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752607Ab2KENkZ (ORCPT ); Mon, 5 Nov 2012 08:40:25 -0500 From: Matthieu CASTET To: linux-kernel@vger.kernel.org Cc: cl@linux.com, akpm@linux-foundation.org, Matthieu CASTET Subject: [PATCH] dmapool : make DMAPOOL_DEBUG detect corruption of free marker Date: Mon, 5 Nov 2012 14:40:05 +0100 Message-Id: <1352122805-30099-1-git-send-email-matthieu.castet@parrot.com> X-Mailer: git-send-email 1.7.10.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1426 Lines: 49 This can help to catch case where hardware is writting after dma free. Signed-off-by: Matthieu Castet --- mm/dmapool.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/mm/dmapool.c b/mm/dmapool.c index c5ab33b..e10898a 100644 --- a/mm/dmapool.c +++ b/mm/dmapool.c @@ -346,6 +346,29 @@ void *dma_pool_alloc(struct dma_pool *pool, gfp_t mem_flags, retval = offset + page->vaddr; *handle = offset + page->dma; #ifdef DMAPOOL_DEBUG + { + int i; + u8 *data = retval; + /* page->offset is stored in first 4 bytes */ + for (i = sizeof(int); i < pool->size; i++) { + if (data[i] != POOL_POISON_FREED) { + if (pool->dev) + dev_err(pool->dev, + "dma_pool_alloc %s, %p (corruped)\n", + pool->name, retval); + else + printk(KERN_ERR + "dma_pool_alloc %s, %p (corruped)\n", + pool->name, retval); + + /* we dump the first 4 bytes even if there are not + POOL_POISON_FREED */ + print_hex_dump(KERN_ERR, "", DUMP_PREFIX_OFFSET, 16, 1, + data, pool->size, 1); + break; + } + } + } memset(retval, POOL_POISON_ALLOCATED, pool->size); #endif done: -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/