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From: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
To: Linux Media Mailing List <linux-media@vger.kernel.org>
Cc: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>,
	Mauro Carvalho Chehab <mchehab@infradead.org>,
	Eddie James <eajames@linux.ibm.com>,
	Joel Stanley <joel@jms.id.au>, Andrew Jeffery <andrew@aj.id.au>,
	openbmc@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org,
	linux-aspeed@lists.ozlabs.org
Subject: [PATCH 3/7] media: aspeed-video: address a protential usage of an unit var
Date: Thu, 22 Aug 2019 16:39:30 -0300	[thread overview]
Message-ID: <7c85f7dc159927a7316dc13f52697f157fb6e2bd.1566502743.git.mchehab+samsung@kernel.org> (raw)
In-Reply-To: <4a411ba155eb062b6575aba0824123c840806c0b.1566502743.git.mchehab+samsung@kernel.org>

While this might not occur in practice, if the device is doing
the right thing, it would be teoretically be possible to have
both hsync_counter and vsync_counter negatives.

If this ever happen, ctrl will be undefined, but the driver
will still call:

	aspeed_video_update(video, VE_CTRL, 0, ctrl);

Change the code to prevent this to happen.

This was warned by cppcheck:

	[drivers/media/platform/aspeed-video.c:653]: (error) Uninitialized variable: ctrl

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
---
 drivers/media/platform/aspeed-video.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/media/platform/aspeed-video.c b/drivers/media/platform/aspeed-video.c
index f899ac3b4a61..4ef37cfc8446 100644
--- a/drivers/media/platform/aspeed-video.c
+++ b/drivers/media/platform/aspeed-video.c
@@ -630,7 +630,7 @@ static void aspeed_video_check_and_set_polarity(struct aspeed_video *video)
 	}
 
 	if (hsync_counter < 0 || vsync_counter < 0) {
-		u32 ctrl;
+		u32 ctrl = 0;
 
 		if (hsync_counter < 0) {
 			ctrl = VE_CTRL_HSYNC_POL;
@@ -650,7 +650,8 @@ static void aspeed_video_check_and_set_polarity(struct aspeed_video *video)
 				V4L2_DV_VSYNC_POS_POL;
 		}
 
-		aspeed_video_update(video, VE_CTRL, 0, ctrl);
+		if (ctrl)
+			aspeed_video_update(video, VE_CTRL, 0, ctrl);
 	}
 }
 
-- 
2.21.0


WARNING: multiple messages have this Message-ID (diff)
From: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
To: Linux Media Mailing List <linux-media@vger.kernel.org>
Cc: linux-aspeed@lists.ozlabs.org, Andrew Jeffery <andrew@aj.id.au>,
	openbmc@lists.ozlabs.org, Eddie James <eajames@linux.ibm.com>,
	Mauro Carvalho Chehab <mchehab@infradead.org>,
	Joel Stanley <joel@jms.id.au>,
	Mauro Carvalho Chehab <mchehab+samsung@kernel.org>,
	linux-arm-kernel@lists.infradead.org
Subject: [PATCH 3/7] media: aspeed-video: address a protential usage of an unit var
Date: Thu, 22 Aug 2019 16:39:30 -0300	[thread overview]
Message-ID: <7c85f7dc159927a7316dc13f52697f157fb6e2bd.1566502743.git.mchehab+samsung@kernel.org> (raw)
In-Reply-To: <4a411ba155eb062b6575aba0824123c840806c0b.1566502743.git.mchehab+samsung@kernel.org>

While this might not occur in practice, if the device is doing
the right thing, it would be teoretically be possible to have
both hsync_counter and vsync_counter negatives.

If this ever happen, ctrl will be undefined, but the driver
will still call:

	aspeed_video_update(video, VE_CTRL, 0, ctrl);

Change the code to prevent this to happen.

This was warned by cppcheck:

	[drivers/media/platform/aspeed-video.c:653]: (error) Uninitialized variable: ctrl

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
---
 drivers/media/platform/aspeed-video.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/media/platform/aspeed-video.c b/drivers/media/platform/aspeed-video.c
index f899ac3b4a61..4ef37cfc8446 100644
--- a/drivers/media/platform/aspeed-video.c
+++ b/drivers/media/platform/aspeed-video.c
@@ -630,7 +630,7 @@ static void aspeed_video_check_and_set_polarity(struct aspeed_video *video)
 	}
 
 	if (hsync_counter < 0 || vsync_counter < 0) {
-		u32 ctrl;
+		u32 ctrl = 0;
 
 		if (hsync_counter < 0) {
 			ctrl = VE_CTRL_HSYNC_POL;
@@ -650,7 +650,8 @@ static void aspeed_video_check_and_set_polarity(struct aspeed_video *video)
 				V4L2_DV_VSYNC_POS_POL;
 		}
 
-		aspeed_video_update(video, VE_CTRL, 0, ctrl);
+		if (ctrl)
+			aspeed_video_update(video, VE_CTRL, 0, ctrl);
 	}
 }
 
-- 
2.21.0


_______________________________________________
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http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

  parent reply	other threads:[~2019-08-22 19:39 UTC|newest]

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-22 19:39 [PATCH 1/7] media: remove include stdarg.h from some drivers Mauro Carvalho Chehab
2019-08-22 19:39 ` [PATCH 2/7] media: vicodec: make life easier for static analyzers Mauro Carvalho Chehab
2019-08-22 19:39 ` Mauro Carvalho Chehab [this message]
2019-08-22 19:39   ` [PATCH 3/7] media: aspeed-video: address a protential usage of an unit var Mauro Carvalho Chehab
2019-08-26 15:12   ` Eddie James
2019-08-26 15:12     ` Eddie James
2019-08-22 19:39 ` [PATCH 4/7] media: ov9650: add a sanity check Mauro Carvalho Chehab
2019-08-23 10:33   ` Sylwester Nawrocki
2019-08-22 19:39 ` [PATCH 5/7] media: use the BIT() macro Mauro Carvalho Chehab
2019-08-22 19:39   ` Mauro Carvalho Chehab
2019-08-23  0:08   ` Laurent Pinchart
2019-08-23  0:08     ` Laurent Pinchart
2019-08-23  0:08     ` Laurent Pinchart
2019-08-23  9:47     ` [PATCH v2 " Mauro Carvalho Chehab
2019-08-23  9:47       ` Mauro Carvalho Chehab
2019-08-23 10:22       ` Sylwester Nawrocki
2019-08-23 10:22         ` Sylwester Nawrocki
2019-08-23 10:22         ` Sylwester Nawrocki
2019-08-23 12:12       ` Benoit Parrot
2019-08-23 12:12         ` Benoit Parrot
2019-08-23 12:12         ` Benoit Parrot
2019-08-23 20:45       ` Laurent Pinchart
2019-08-23 20:45         ` Laurent Pinchart
2019-08-23 20:45         ` Laurent Pinchart
2019-08-22 19:39 ` [PATCH 6/7] media: don't do an unsigned int with a 31 bit shift Mauro Carvalho Chehab
2019-08-22 19:39   ` Mauro Carvalho Chehab
2019-08-22 19:39   ` Mauro Carvalho Chehab
2019-08-23  9:08   ` Marc Gonzalez
2019-08-23 10:20     ` Mauro Carvalho Chehab
2019-08-23 11:09       ` Marc Gonzalez
2019-08-29 17:03   ` Kees Cook
2019-08-29 17:03     ` Kees Cook
2019-08-29 17:03     ` Kees Cook
2019-08-22 19:39 ` [PATCH 7/7] media: ngene: don't try to memcpy from NULL Mauro Carvalho Chehab
2019-08-22 19:43   ` Mauro Carvalho Chehab

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