From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj2-f43.google.com (mail-pj2-f43.google.com [74.125.227.171]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 02ECB4BA1F9 for ; Mon, 5 Oct 2026 19:26:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.227.171 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791228387; cv=none; b=moK08Q8ySd5cGifusxPnE+yzplj+EnIidblZP+gRYZcJ7PBIcQlhIoc9f3nuFC7/c1bPr/VOndzzZaukL2KdcYGBAuBzEnHcSWXIjGG7PJq18UUicprpHl8Fhiy441uoUF86MT9t4xxN6ltBKQvGTlQuylsL5vq+YxNmKkVYrqw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791228387; c=relaxed/simple; bh=qLo0sLQGLGk/Qb1aLrPVxsDkLEujWQRRC1IGWA5JPvw=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=Iy+odixXU1p0Xhg+CkF128FDtEnbEuULllqYZwgEs+R9koaXGOUyK/W3SO9CyXpBsPldsSC3Y9wUZ7u78RFYyn5nYS3GdVCKPfe0aHrndwHSYEBC7nBvPVqCDZQpijtUk1KcBjvPfBvVajH/pCHjlQRggaFFIPZcvYSx4lnMbP8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=LfJfX7sD; arc=none smtp.client-ip=74.125.227.171 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="LfJfX7sD" Received: by mail-pj2-f43.google.com with SMTP id 98e67ed59e1d1-3a49573b8bdso1460492a91.2 for ; Mon, 05 Oct 2026 12:26:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1791228385; x=1791833185; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to:content-type; bh=Vw763NV5BjSaZVhghdUwJpS8A2L5IAuXgkLi18vef04=; b=LfJfX7sDLcrlC2YFzXRa8lQDTQ1idEntfujB+Ef0r9KDtDq2aUc7VPGHL7tyegu8c/ RJDEeUqCdG2Nf3vvV9iexCWuxX/RSzsnYQ9NUVXP+tpAuZOrDfA6s+vmt1miL5Yblf0s M+SJSHuKhwxJr0EOvcM15SF+MF732Xi8syZsUiEde6HZ1ve6BijFMxjcv6C1Oa/BJnp2 rqAN4OAWduogL9dW6WfgSCeO2hDiLSc2Xdb5K6Ca3b0L72zlsgsMRHi0U8UFwA4zfnSx OzQCDaf3Q3OdcqaCf5wgyvt+sXNsJzsIcXWS8qrK4VzQM2e+LKPKzty1iz4uCZyg+Je7 bO1Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1791228385; x=1791833185; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=Vw763NV5BjSaZVhghdUwJpS8A2L5IAuXgkLi18vef04=; b=M5/8tmhi9SkQrI1/DEqXJ2Bp+WUKJTTfq/QKM44xgEbFYuY0MZtuuHGQH2j/kkmjDH gushijI2GYwalRpyi1OtmvW2EPQeXYCLsEWyQ7RybJp72ndQBxUNgrdwdM4EBi1ZHd0O TgxRgc7s5V2J+UOuXfxJ1O6Hb2aDxGDJ2kQ2m5dsIcMGdmi4dk+RimGXz+dDFzu8dcIv +U7AhY6ToTSbZex/NItplv4NJJYXoZr5MsxQO9byvS7GTVbkkbucU9JVl45FTT6YJg1c mA375fZEePFxoon/DEQuSGnubh1Nkls+stPo0bBkls1H8HnW+lz/2GYtHyUAuMlpXsfZ ai7Q== X-Forwarded-Encrypted: i=1; AKwUvBw5m9yCbOj4m4f7nIexJiS/JyO6UIK4mj36V5K6OgrE8iC9F82S2MvZJCOxGCwkewcQwnI6GsRM9xTYvqA=@vger.kernel.org X-Gm-Message-State: AFq9FYI9/oaX50P+c4zQnS8aJZpXb6faiI90Skc6f9NVnhlamyKqMpdF JosqkyobK9mqQ5qermsR/rizM6el5wEVKK4sICBcnT4/NMzl2XXMdC2M X-Gm-Gg: AYBFou3tRWmaj36GvIlkmfPLLOFPJEHbB4Zjs/iyDBI0UZ57ZmEmJTc0XtTL63TiK7l nFN83mE89VZqqDAYQnwNkNPxAYD0iApv2COsjflUiLlusTpGJYmpvCnWr/MDmj7Xu+p3Lccl3ak mvKJfQKfi+1v1H0DSscadwa7KtSsRbTFEIYMopCHZ0SXCuE+mRaW5ZgZzK5wBM/GOr02SNJKmze jdxFkGVMr+CeH2nVv2IfTl4NPy2mmyTFdmHvjB6KOtDZ9TXrWSLsbdU4rFUzfVvYekKfM6AEa/B qyhFQ2uykyZg599mlbIdOi960Hk0ff12TW6QtdgSai4/iot0ZUfXBhtY3HpDajh7uWjkUyXyfGL pw19mMhcDAhAYwshJhP+gHz5LzH4xgSzTGb5+3EVnn1uL3Y777DSztBxToDJTRiTe0+DpULveAl x3SJIrOgk5gbVzHqmWRGziaDAwzx0gi8RCh9w5bLtPMOnXPNKfM2S+4O67cHkh1/BN9zo3YRYh1 RqE8xOZwr8oHAIxI8qlyvlfQGjPijBTYfBd+4xO+i5cwGfcjm1DvtWPMZYH5/hOUIP9OIxBZ8pE 4yN+jy93IOp2PWlmWxJwwk+qcI8ueJ+ENiDjibYErF8chXUdrcuxTgY9nAs= X-Received: by 2002:a17:90b:498e:b0:3a7:9ad9:68e1 with SMTP id 98e67ed59e1d1-3a79ad96bd7mr6814909a91.13.1791228385236; Mon, 05 Oct 2026 12:26:25 -0700 (PDT) Received: from ryzen.lan ([2601:644:8000:7a86::e35]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-3a853b92679sm850955a91.6.2026.10.05.12.26.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 05 Oct 2026 12:26:24 -0700 (PDT) From: Rosen Penev To: dmaengine@vger.kernel.org Cc: Lizhi Hou , Brian Xu , Raj Kumar Rampelli , Vinod Koul , Frank Li , Michal Simek , Kees Cook , "Gustavo A. R. Silva" , linux-arm-kernel@lists.infradead.org (moderated list:ARM/ZYNQ ARCHITECTURE), linux-kernel@vger.kernel.org (open list), linux-hardening@vger.kernel.org (open list:KERNEL HARDENING (not covered by other areas):Keyword:\b__counted_by(_le|_be|_ptr)?\b) Subject: [PATCH v2] dmaengine: xilinx: xdma: use kzalloc_flex() Date: Mon, 5 Oct 2026 12:26:21 -0700 Message-ID: <20261005192621.99880-1-rosenp@gmail.com> X-Mailer: git-send-email 2.56.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Change desc_blocks to a flexible array member so the descriptor and its block array are allocated together, removing one allocation and its error handling. Add __counted_by for extra runtime analysis, and set dblk_num right after allocation which is already done by kzalloc_flex() for GCC >= 15. Assisted-by: LLM Signed-off-by: Rosen Penev --- drivers/dma/xilinx/xdma.c | 15 +++++---------- 1 file changed, 5 insertions(+), 10 deletions(-) diff --git a/drivers/dma/xilinx/xdma.c b/drivers/dma/xilinx/xdma.c index 8d4a5d14e8db..16d202722245 100644 --- a/drivers/dma/xilinx/xdma.c +++ b/drivers/dma/xilinx/xdma.c @@ -81,7 +81,6 @@ struct xdma_chan { * @vdesc: Virtual DMA descriptor * @chan: DMA channel pointer * @dir: Transferring direction of the request - * @desc_blocks: Hardware descriptor blocks * @dblk_num: Number of hardware descriptor blocks * @desc_num: Number of hardware descriptors * @completed_desc_num: Completed hardware descriptors @@ -91,12 +90,12 @@ struct xdma_chan { * @period_size: Size of a period in bytes in cyclic transfers * @frames_left: Number of frames left in interleaved DMA transfer * @error: tx error flag + * @desc_blocks: Hardware descriptor blocks */ struct xdma_desc { struct virt_dma_desc vdesc; struct xdma_chan *chan; enum dma_transfer_direction dir; - struct xdma_desc_block *desc_blocks; u32 dblk_num; u32 desc_num; u32 completed_desc_num; @@ -106,6 +105,7 @@ struct xdma_desc { u32 period_size; u32 frames_left; bool error; + struct xdma_desc_block desc_blocks[] __counted_by(dblk_num); }; #define XDMA_DEV_STATUS_REG_DMA BIT(0) @@ -255,7 +255,6 @@ static void xdma_free_desc(struct virt_dma_desc *vdesc) sw_desc->desc_blocks[i].virt_addr, sw_desc->desc_blocks[i].dma_addr); } - kfree(sw_desc->desc_blocks); kfree(sw_desc); } @@ -276,26 +275,22 @@ xdma_alloc_desc(struct xdma_chan *chan, u32 desc_num, bool cyclic) void *addr; int i, j; - sw_desc = kzalloc_obj(*sw_desc, GFP_NOWAIT); + dblk_num = DIV_ROUND_UP(desc_num, XDMA_DESC_ADJACENT); + sw_desc = kzalloc_flex(*sw_desc, desc_blocks, dblk_num, GFP_NOWAIT); if (!sw_desc) return NULL; + sw_desc->dblk_num = dblk_num; sw_desc->chan = chan; sw_desc->desc_num = desc_num; sw_desc->cyclic = cyclic; sw_desc->error = false; - dblk_num = DIV_ROUND_UP(desc_num, XDMA_DESC_ADJACENT); - sw_desc->desc_blocks = kzalloc_objs(*sw_desc->desc_blocks, dblk_num, - GFP_NOWAIT); - if (!sw_desc->desc_blocks) - goto failed; if (cyclic) control = XDMA_DESC_CONTROL_CYCLIC; else control = XDMA_DESC_CONTROL(1, 0); - sw_desc->dblk_num = dblk_num; for (i = 0; i < sw_desc->dblk_num; i++) { addr = dma_pool_alloc(chan->desc_pool, GFP_NOWAIT, &dma_addr); if (!addr) -- 2.56.0