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From: Rosen Penev <rosenp@gmail.com>
To: linux-kernel@vger.kernel.org
Cc: Ian Abbott <abbotti@mev.co.uk>,
	H Hartley Sweeten <hsweeten@visionengravers.com>,
	Kees Cook <kees@kernel.org>,
	"Gustavo A. R. Silva" <gustavoars@kernel.org>,
	linux-hardening@vger.kernel.org (open list:KERNEL HARDENING (not
	covered by other areas):Keyword:\b__counted_by(_le|_be)?\b)
Subject: [PATCH] comedi: isadma: use kzalloc_flex
Date: Wed, 11 Mar 2026 16:24:59 -0700	[thread overview]
Message-ID: <20260311232459.18407-1-rosenp@gmail.com> (raw)

Switched struct pointer member to a flexible array member to get rid of
kzalloc_objs as there's no need for them to be separately allocated.

AAdded __counted_by for extra runtime analysis.

Signed-off-by: Rosen Penev <rosenp@gmail.com>
---
 drivers/comedi/drivers/comedi_isadma.c | 21 +++++++--------------
 include/linux/comedi/comedi_isadma.h   |  2 +-
 2 files changed, 8 insertions(+), 15 deletions(-)

diff --git a/drivers/comedi/drivers/comedi_isadma.c b/drivers/comedi/drivers/comedi_isadma.c
index 04ce3eb9ae4f..c35811bde735 100644
--- a/drivers/comedi/drivers/comedi_isadma.c
+++ b/drivers/comedi/drivers/comedi_isadma.c
@@ -161,14 +161,10 @@ struct comedi_isadma *comedi_isadma_alloc(struct comedi_device *dev,
 	if (n_desc < 1 || n_desc > 2)
 		goto no_dma;
 
-	dma = kzalloc_obj(*dma);
+	dma = kzalloc_flex(*dma, desc, n_desc);
 	if (!dma)
 		goto no_dma;
 
-	desc = kzalloc_objs(*desc, n_desc);
-	if (!desc)
-		goto no_dma;
-	dma->desc = desc;
 	dma->n_desc = n_desc;
 	if (dev->hw_dev) {
 		dma->dev = dev->hw_dev;
@@ -231,15 +227,12 @@ void comedi_isadma_free(struct comedi_isadma *dma)
 	if (!dma)
 		return;
 
-	if (dma->desc) {
-		for (i = 0; i < dma->n_desc; i++) {
-			desc = &dma->desc[i];
-			if (desc->virt_addr)
-				dma_free_coherent(dma->dev, desc->maxsize,
-						  desc->virt_addr,
-						  desc->hw_addr);
-		}
-		kfree(dma->desc);
+	for (i = 0; i < dma->n_desc; i++) {
+		desc = &dma->desc[i];
+		if (desc->virt_addr)
+			dma_free_coherent(dma->dev, desc->maxsize,
+					  desc->virt_addr,
+					  desc->hw_addr);
 	}
 	if (dma->chan2 && dma->chan2 != dma->chan)
 		free_dma(dma->chan2);
diff --git a/include/linux/comedi/comedi_isadma.h b/include/linux/comedi/comedi_isadma.h
index 9d2b12db7e6e..7514ce222fa6 100644
--- a/include/linux/comedi/comedi_isadma.h
+++ b/include/linux/comedi/comedi_isadma.h
@@ -48,11 +48,11 @@ struct comedi_isadma_desc {
  */
 struct comedi_isadma {
 	struct device *dev;
-	struct comedi_isadma_desc *desc;
 	int n_desc;
 	int cur_dma;
 	unsigned int chan;
 	unsigned int chan2;
+	struct comedi_isadma_desc desc[] __counted_by(n_desc);
 };
 
 #if IS_ENABLED(CONFIG_ISA_DMA_API)
-- 
2.53.0


                 reply	other threads:[~2026-03-11 23:25 UTC|newest]

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