From patchwork Fri Jan 20 10:06:23 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: shravan kumar X-Patchwork-Id: 13109590 X-Patchwork-Delegate: palmer@dabbelt.com Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D39F1C25B4E for ; Fri, 20 Jan 2023 10:11:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-ID:Date:Subject:CC :To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=m7K6pTXjHJkrNkQXeQIsqMNA6YQukhomZQ0seCrVWWQ=; b=2avfVfDsY3O2Zh ZKwmYV+xXbGZ8UhjUXvIri4XM8r5ufB/6zZemJ4CYDqjNYEjYIaKyO52+uWaZ6UxhMsnHrO0/S7Zo G1Fp8RvDrsP4r/bXNg3srcECIarpdn4EGcxcJErDvwir8UaW3X0IhwGuLFo6dd6peVbW/lf1KgfQk Hbxic9B796pAqL7v0AlHXNURwGoNXJisSsbp3QwBO3kAXGA588zrJyS9zNYrMDMlYRXzuCnuIP2t+ ZPrVSLN/iNvCyMWfU0zQSbTD4uE9enUcrUyu1vcUqZU7kqr4deEoZqQt9PAMr48ohC/9ltwhGsaYm kgUVZV193WYUj36CnWIA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1pIoNA-009hdF-2T; Fri, 20 Jan 2023 10:11:48 +0000 Received: from esa.microchip.iphmx.com ([68.232.154.123]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1pIoIL-009fXF-4H for linux-riscv@lists.infradead.org; Fri, 20 Jan 2023 10:06:50 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=microchip.com; i=@microchip.com; q=dns/txt; s=mchp; t=1674209209; x=1705745209; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=s8RVOfsWfXmS7vuK9YlhjZHo4/cTdmhqpji15rJG740=; b=LChK2G1xnufqLSZVdogPVNJp1GO+tokLctdRu3f2DZlf1Xd+JjZLY+Nl li2F7dKzFQQqWcrShSvxiDq6OwZpMfPARuEPGPu/pMhAaIyQahhRZhXYd lQ/4AzcZg8O5mR8dbqMr6MIQckx1N7NntFinFhJqATnID9GoaVyqpqQJy 9b/F3xkRpZSJrxPmcVrBx96BXX1KqnGJv+1rg98KaIyD8Gs/j/9uXo4p4 dGttlLKbpFR+HruwC0wf/Hejpag4vBCoeI5ZPlBdXj6Hvt2mDxT0quhdQ wBTw1QGpMXbzGdQqrzlBPwP6eJa2j6CgmMBEWzDhQTcwfPejlB6Whi206 Q==; X-IronPort-AV: E=Sophos;i="5.97,231,1669100400"; d="scan'208";a="196675868" Received: from unknown (HELO email.microchip.com) ([170.129.1.10]) by esa2.microchip.iphmx.com with ESMTP/TLS/AES256-SHA256; 20 Jan 2023 03:06:47 -0700 Received: from chn-vm-ex03.mchp-main.com (10.10.85.151) by chn-vm-ex02.mchp-main.com (10.10.85.144) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.16; Fri, 20 Jan 2023 03:06:47 -0700 Received: from microchip1-OptiPlex-9020.microchip.com (10.10.115.15) by chn-vm-ex03.mchp-main.com (10.10.85.151) with Microsoft SMTP Server id 15.1.2507.16 via Frontend Transport; Fri, 20 Jan 2023 03:06:44 -0700 From: shravan kumar To: , , , CC: , , , Subject: [PATCH v1] dmaengine: sf-pdma: pdma_desc memory leak fix Date: Fri, 20 Jan 2023 15:36:23 +0530 Message-ID: <20230120100623.3530634-1-shravan.chippa@microchip.com> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230120_020649_297804_106ED686 X-CRM114-Status: GOOD ( 11.62 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org From: Shravan Chippa Commit b2cc5c465c2c ("dmaengine: sf-pdma: Add multithread support for a DMA channel") changed sf_pdma_prep_dma_memcpy() to unconditionally allocate a new sf_pdma_desc each time it is called. The driver previously recycled descs, by checking the in_use flag, only allocating additional descs if the existing one was in use. This logic was removed in commit b2cc5c465c2c ("dmaengine: sf-pdma: Add multithread support for a DMA channel"), but sf_pdma_free_desc() was not changed to handle the new behaviour. As a result, each time sf_pdma_prep_dma_memcpy() is called, the previous descriptor is leaked, over time leading to memory starvation: unreferenced object 0xffffffe008447300 (size 192): comm "irq/39-mchp_dsc", pid 343, jiffies 4294906910 (age 981.200s) hex dump (first 32 bytes): 00 00 00 ff 00 00 00 00 b8 c1 00 00 00 00 00 00 ................ 00 00 70 08 10 00 00 00 00 00 00 c0 00 00 00 00 ..p............. backtrace: [<00000000064a04f4>] kmemleak_alloc+0x1e/0x28 [<00000000018927a7>] kmem_cache_alloc+0x11e/0x178 [<000000002aea8d16>] sf_pdma_prep_dma_memcpy+0x40/0x112 Add the missing kfree() to sf_pdma_free_desc(), and remove the redundant in_use flag. Fixes: b2cc5c465c2c ("dmaengine: sf-pdma: Add multithread support for a DMA channel") Signed-off-by: Shravan Chippa Reviewed-by: Conor Dooley --- drivers/dma/sf-pdma/sf-pdma.c | 3 +-- drivers/dma/sf-pdma/sf-pdma.h | 1 - 2 files changed, 1 insertion(+), 3 deletions(-) diff --git a/drivers/dma/sf-pdma/sf-pdma.c b/drivers/dma/sf-pdma/sf-pdma.c index 6b524eb6bcf3..e578ad556949 100644 --- a/drivers/dma/sf-pdma/sf-pdma.c +++ b/drivers/dma/sf-pdma/sf-pdma.c @@ -96,7 +96,6 @@ sf_pdma_prep_dma_memcpy(struct dma_chan *dchan, dma_addr_t dest, dma_addr_t src, if (!desc) return NULL; - desc->in_use = true; desc->dirn = DMA_MEM_TO_MEM; desc->async_tx = vchan_tx_prep(&chan->vchan, &desc->vdesc, flags); @@ -290,7 +289,7 @@ static void sf_pdma_free_desc(struct virt_dma_desc *vdesc) struct sf_pdma_desc *desc; desc = to_sf_pdma_desc(vdesc); - desc->in_use = false; + kfree(desc); } static void sf_pdma_donebh_tasklet(struct tasklet_struct *t) diff --git a/drivers/dma/sf-pdma/sf-pdma.h b/drivers/dma/sf-pdma/sf-pdma.h index dcb3687bd5da..5c398a83b491 100644 --- a/drivers/dma/sf-pdma/sf-pdma.h +++ b/drivers/dma/sf-pdma/sf-pdma.h @@ -78,7 +78,6 @@ struct sf_pdma_desc { u64 src_addr; struct virt_dma_desc vdesc; struct sf_pdma_chan *chan; - bool in_use; enum dma_transfer_direction dirn; struct dma_async_tx_descriptor *async_tx; };