[PATCH 1/3] ASoC: Intel: catpt: remove check of list iterator against head past the loop body

[PATCH 1/3] ASoC: Intel: catpt: remove check of list iterator against head past the loop body

[Jakob Koschel]

When list_for_each_entry() completes the iteration over the whole list
without breaking the loop, the iterator value will be a bogus pointer
computed based on the head element.

While it is safe to use the pointer to determine if it was computed
based on the head element, either with list_entry_is_head() or
&pos->member == head, using the iterator variable after the loop should
be avoided.

In preparation to limiting the scope of a list iterator to the list
traversal loop, use a dedicated pointer to point to the found element [1].

Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ [1]
Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com>
---
 sound/soc/intel/catpt/pcm.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/sound/soc/intel/catpt/pcm.c b/sound/soc/intel/catpt/pcm.c
index a26000cd5ceb..b103b2d4026e 100644
--- a/sound/soc/intel/catpt/pcm.c
+++ b/sound/soc/intel/catpt/pcm.c
@@ -330,7 +330,8 @@ static int catpt_dai_apply_usettings(struct snd_soc_dai *dai,
 				     struct catpt_stream_runtime *stream)
 {
 	struct snd_soc_component *component = dai->component;
-	struct snd_kcontrol *pos;
+	struct snd_kcontrol *pos = NULL;
+	struct snd_kcontrol *iter;
 	struct catpt_dev *cdev = dev_get_drvdata(dai->dev);
 	const char *name;
 	int ret;
@@ -354,12 +355,14 @@ static int catpt_dai_apply_usettings(struct snd_soc_dai *dai,
 		return 0;
 	}
 
-	list_for_each_entry(pos, &component->card->snd_card->controls, list) {
-		if (pos->private_data == component &&
-		    !strncmp(name, pos->id.name, sizeof(pos->id.name)))
+	list_for_each_entry(iter, &component->card->snd_card->controls, list) {
+		if (iter->private_data == component &&
+		    !strncmp(name, iter->id.name, sizeof(iter->id.name))) {
+			pos = iter;
 			break;
+		}
 	}
-	if (list_entry_is_head(pos, &component->card->snd_card->controls, list))
+	if (!pos)
 		return -ENOENT;
 
 	if (stream->template->type != CATPT_STRM_TYPE_LOOPBACK)

base-commit: f82da161ea75dc4db21b2499e4b1facd36dab275
-- 
2.25.1

[PATCH 1/3] ASoC: Intel: catpt: remove check of list iterator against head past the loop body

[Jakob Koschel]

When list_for_each_entry() completes the iteration over the whole list
without breaking the loop, the iterator value will be a bogus pointer
computed based on the head element.

While it is safe to use the pointer to determine if it was computed
based on the head element, either with list_entry_is_head() or
&pos->member == head, using the iterator variable after the loop should
be avoided.

In preparation to limiting the scope of a list iterator to the list
traversal loop, use a dedicated pointer to point to the found element [1].

Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ [1]
Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com>
---
 sound/soc/intel/catpt/pcm.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/sound/soc/intel/catpt/pcm.c b/sound/soc/intel/catpt/pcm.c
index a26000cd5ceb..b103b2d4026e 100644
--- a/sound/soc/intel/catpt/pcm.c
+++ b/sound/soc/intel/catpt/pcm.c
@@ -330,7 +330,8 @@ static int catpt_dai_apply_usettings(struct snd_soc_dai *dai,
 				     struct catpt_stream_runtime *stream)
 {
 	struct snd_soc_component *component = dai->component;
-	struct snd_kcontrol *pos;
+	struct snd_kcontrol *pos = NULL;
+	struct snd_kcontrol *iter;
 	struct catpt_dev *cdev = dev_get_drvdata(dai->dev);
 	const char *name;
 	int ret;
@@ -354,12 +355,14 @@ static int catpt_dai_apply_usettings(struct snd_soc_dai *dai,
 		return 0;
 	}
 
-	list_for_each_entry(pos, &component->card->snd_card->controls, list) {
-		if (pos->private_data == component &&
-		    !strncmp(name, pos->id.name, sizeof(pos->id.name)))
+	list_for_each_entry(iter, &component->card->snd_card->controls, list) {
+		if (iter->private_data == component &&
+		    !strncmp(name, iter->id.name, sizeof(iter->id.name))) {
+			pos = iter;
 			break;
+		}
 	}
-	if (list_entry_is_head(pos, &component->card->snd_card->controls, list))
+	if (!pos)
 		return -ENOENT;
 
 	if (stream->template->type != CATPT_STRM_TYPE_LOOPBACK)

base-commit: f82da161ea75dc4db21b2499e4b1facd36dab275
-- 
2.25.1

[PATCH 1/3] ASoC: Intel: catpt: remove check of list iterator against head past the loop body

[Jakob Koschel]

When list_for_each_entry() completes the iteration over the whole list
without breaking the loop, the iterator value will be a bogus pointer
computed based on the head element.

While it is safe to use the pointer to determine if it was computed
based on the head element, either with list_entry_is_head() or
&pos->member == head, using the iterator variable after the loop should
be avoided.

In preparation to limiting the scope of a list iterator to the list
traversal loop, use a dedicated pointer to point to the found element [1].

Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ [1]
Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com>
---
 sound/soc/intel/catpt/pcm.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/sound/soc/intel/catpt/pcm.c b/sound/soc/intel/catpt/pcm.c
index a26000cd5ceb..b103b2d4026e 100644
--- a/sound/soc/intel/catpt/pcm.c
+++ b/sound/soc/intel/catpt/pcm.c
@@ -330,7 +330,8 @@ static int catpt_dai_apply_usettings(struct snd_soc_dai *dai,
 				     struct catpt_stream_runtime *stream)
 {
 	struct snd_soc_component *component = dai->component;
-	struct snd_kcontrol *pos;
+	struct snd_kcontrol *pos = NULL;
+	struct snd_kcontrol *iter;
 	struct catpt_dev *cdev = dev_get_drvdata(dai->dev);
 	const char *name;
 	int ret;
@@ -354,12 +355,14 @@ static int catpt_dai_apply_usettings(struct snd_soc_dai *dai,
 		return 0;
 	}
 
-	list_for_each_entry(pos, &component->card->snd_card->controls, list) {
-		if (pos->private_data == component &&
-		    !strncmp(name, pos->id.name, sizeof(pos->id.name)))
+	list_for_each_entry(iter, &component->card->snd_card->controls, list) {
+		if (iter->private_data == component &&
+		    !strncmp(name, iter->id.name, sizeof(iter->id.name))) {
+			pos = iter;
 			break;
+		}
 	}
-	if (list_entry_is_head(pos, &component->card->snd_card->controls, list))
+	if (!pos)
 		return -ENOENT;
 
 	if (stream->template->type != CATPT_STRM_TYPE_LOOPBACK)

base-commit: f82da161ea75dc4db21b2499e4b1facd36dab275
-- 
2.25.1


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

[PATCH 2/3] ASoC: sprd: remove check of list iterator against head past the loop body

[Jakob Koschel]

When list_for_each_entry() completes the iteration over the whole list
without breaking the loop, the iterator value will be a bogus pointer
computed based on the head element.

While it is safe to use the pointer to determine if it was computed
based on the head element, either with list_entry_is_head() or
&pos->member == head, using the iterator variable after the loop should
be avoided.

In preparation to limiting the scope of a list iterator to the list
traversal loop, use a dedicated pointer to point to the found element [1].

Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ [1]
Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com>
---
 sound/soc/sprd/sprd-mcdt.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/sound/soc/sprd/sprd-mcdt.c b/sound/soc/sprd/sprd-mcdt.c
index f6a55fa60c1b..6e27789a0df5 100644
--- a/sound/soc/sprd/sprd-mcdt.c
+++ b/sound/soc/sprd/sprd-mcdt.c
@@ -866,20 +866,19 @@ EXPORT_SYMBOL_GPL(sprd_mcdt_chan_dma_disable);
 struct sprd_mcdt_chan *sprd_mcdt_request_chan(u8 channel,
 					      enum sprd_mcdt_channel_type type)
 {
-	struct sprd_mcdt_chan *temp;
+	struct sprd_mcdt_chan *temp = NULL;
+	struct sprd_mcdt_chan *iter;
 
 	mutex_lock(&sprd_mcdt_list_mutex);
 
-	list_for_each_entry(temp, &sprd_mcdt_chan_list, list) {
-		if (temp->type == type && temp->id == channel) {
-			list_del_init(&temp->list);
+	list_for_each_entry(iter, &sprd_mcdt_chan_list, list) {
+		if (iter->type == type && iter->id == channel) {
+			list_del_init(&iter->list);
+			temp = iter;
 			break;
 		}
 	}
 
-	if (list_entry_is_head(temp, &sprd_mcdt_chan_list, list))
-		temp = NULL;
-
 	mutex_unlock(&sprd_mcdt_list_mutex);
 
 	return temp;
-- 
2.25.1

[PATCH 2/3] ASoC: sprd: remove check of list iterator against head past the loop body

[Jakob Koschel]

When list_for_each_entry() completes the iteration over the whole list
without breaking the loop, the iterator value will be a bogus pointer
computed based on the head element.

While it is safe to use the pointer to determine if it was computed
based on the head element, either with list_entry_is_head() or
&pos->member == head, using the iterator variable after the loop should
be avoided.

In preparation to limiting the scope of a list iterator to the list
traversal loop, use a dedicated pointer to point to the found element [1].

Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ [1]
Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com>
---
 sound/soc/sprd/sprd-mcdt.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/sound/soc/sprd/sprd-mcdt.c b/sound/soc/sprd/sprd-mcdt.c
index f6a55fa60c1b..6e27789a0df5 100644
--- a/sound/soc/sprd/sprd-mcdt.c
+++ b/sound/soc/sprd/sprd-mcdt.c
@@ -866,20 +866,19 @@ EXPORT_SYMBOL_GPL(sprd_mcdt_chan_dma_disable);
 struct sprd_mcdt_chan *sprd_mcdt_request_chan(u8 channel,
 					      enum sprd_mcdt_channel_type type)
 {
-	struct sprd_mcdt_chan *temp;
+	struct sprd_mcdt_chan *temp = NULL;
+	struct sprd_mcdt_chan *iter;
 
 	mutex_lock(&sprd_mcdt_list_mutex);
 
-	list_for_each_entry(temp, &sprd_mcdt_chan_list, list) {
-		if (temp->type == type && temp->id == channel) {
-			list_del_init(&temp->list);
+	list_for_each_entry(iter, &sprd_mcdt_chan_list, list) {
+		if (iter->type == type && iter->id == channel) {
+			list_del_init(&iter->list);
+			temp = iter;
 			break;
 		}
 	}
 
-	if (list_entry_is_head(temp, &sprd_mcdt_chan_list, list))
-		temp = NULL;
-
 	mutex_unlock(&sprd_mcdt_list_mutex);
 
 	return temp;
-- 
2.25.1

[PATCH 2/3] ASoC: sprd: remove check of list iterator against head past the loop body

[Jakob Koschel]

When list_for_each_entry() completes the iteration over the whole list
without breaking the loop, the iterator value will be a bogus pointer
computed based on the head element.

While it is safe to use the pointer to determine if it was computed
based on the head element, either with list_entry_is_head() or
&pos->member == head, using the iterator variable after the loop should
be avoided.

In preparation to limiting the scope of a list iterator to the list
traversal loop, use a dedicated pointer to point to the found element [1].

Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ [1]
Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com>
---
 sound/soc/sprd/sprd-mcdt.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/sound/soc/sprd/sprd-mcdt.c b/sound/soc/sprd/sprd-mcdt.c
index f6a55fa60c1b..6e27789a0df5 100644
--- a/sound/soc/sprd/sprd-mcdt.c
+++ b/sound/soc/sprd/sprd-mcdt.c
@@ -866,20 +866,19 @@ EXPORT_SYMBOL_GPL(sprd_mcdt_chan_dma_disable);
 struct sprd_mcdt_chan *sprd_mcdt_request_chan(u8 channel,
 					      enum sprd_mcdt_channel_type type)
 {
-	struct sprd_mcdt_chan *temp;
+	struct sprd_mcdt_chan *temp = NULL;
+	struct sprd_mcdt_chan *iter;
 
 	mutex_lock(&sprd_mcdt_list_mutex);
 
-	list_for_each_entry(temp, &sprd_mcdt_chan_list, list) {
-		if (temp->type == type && temp->id == channel) {
-			list_del_init(&temp->list);
+	list_for_each_entry(iter, &sprd_mcdt_chan_list, list) {
+		if (iter->type == type && iter->id == channel) {
+			list_del_init(&iter->list);
+			temp = iter;
 			break;
 		}
 	}
 
-	if (list_entry_is_head(temp, &sprd_mcdt_chan_list, list))
-		temp = NULL;
-
 	mutex_unlock(&sprd_mcdt_list_mutex);
 
 	return temp;
-- 
2.25.1


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

[PATCH 3/3] ASoC: atmel-ssc: replace usage of found with dedicated list iterator variable

[Jakob Koschel]

To move the list iterator variable into the list_for_each_entry_*()
macro in the future it should be avoided to use the list iterator
variable after the loop body.

To *never* use the list iterator variable after the loop it was
concluded to use a separate iterator variable instead of a
found boolean [1].

This removes the need to use a found variable and simply checking if
the variable was set, can determine if the break/goto was hit.

Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ [1]
Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com>
---
 drivers/misc/atmel-ssc.c | 19 +++++++++----------
 1 file changed, 9 insertions(+), 10 deletions(-)

diff --git a/drivers/misc/atmel-ssc.c b/drivers/misc/atmel-ssc.c
index d6cd5537126c..343e25555fbb 100644
--- a/drivers/misc/atmel-ssc.c
+++ b/drivers/misc/atmel-ssc.c
@@ -25,25 +25,24 @@ static LIST_HEAD(ssc_list);
 
 struct ssc_device *ssc_request(unsigned int ssc_num)
 {
-	int ssc_valid = 0;
-	struct ssc_device *ssc;
+	struct ssc_device *ssc = NULL, *iter;
 
 	mutex_lock(&user_lock);
-	list_for_each_entry(ssc, &ssc_list, list) {
-		if (ssc->pdev->dev.of_node) {
-			if (of_alias_get_id(ssc->pdev->dev.of_node, "ssc")
+	list_for_each_entry(iter, &ssc_list, list) {
+		if (iter->pdev->dev.of_node) {
+			if (of_alias_get_id(iter->pdev->dev.of_node, "ssc")
 				== ssc_num) {
-				ssc->pdev->id = ssc_num;
-				ssc_valid = 1;
+				iter->pdev->id = ssc_num;
+				ssc = iter;
 				break;
 			}
-		} else if (ssc->pdev->id == ssc_num) {
-			ssc_valid = 1;
+		} else if (iter->pdev->id == ssc_num) {
+			ssc = iter;
 			break;
 		}
 	}
 
-	if (!ssc_valid) {
+	if (!ssc) {
 		mutex_unlock(&user_lock);
 		pr_err("ssc: ssc%d platform device is missing\n", ssc_num);
 		return ERR_PTR(-ENODEV);
-- 
2.25.1

[PATCH 3/3] ASoC: atmel-ssc: replace usage of found with dedicated list iterator variable

[Jakob Koschel]

To move the list iterator variable into the list_for_each_entry_*()
macro in the future it should be avoided to use the list iterator
variable after the loop body.

To *never* use the list iterator variable after the loop it was
concluded to use a separate iterator variable instead of a
found boolean [1].

This removes the need to use a found variable and simply checking if
the variable was set, can determine if the break/goto was hit.

Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ [1]
Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com>
---
 drivers/misc/atmel-ssc.c | 19 +++++++++----------
 1 file changed, 9 insertions(+), 10 deletions(-)

diff --git a/drivers/misc/atmel-ssc.c b/drivers/misc/atmel-ssc.c
index d6cd5537126c..343e25555fbb 100644
--- a/drivers/misc/atmel-ssc.c
+++ b/drivers/misc/atmel-ssc.c
@@ -25,25 +25,24 @@ static LIST_HEAD(ssc_list);
 
 struct ssc_device *ssc_request(unsigned int ssc_num)
 {
-	int ssc_valid = 0;
-	struct ssc_device *ssc;
+	struct ssc_device *ssc = NULL, *iter;
 
 	mutex_lock(&user_lock);
-	list_for_each_entry(ssc, &ssc_list, list) {
-		if (ssc->pdev->dev.of_node) {
-			if (of_alias_get_id(ssc->pdev->dev.of_node, "ssc")
+	list_for_each_entry(iter, &ssc_list, list) {
+		if (iter->pdev->dev.of_node) {
+			if (of_alias_get_id(iter->pdev->dev.of_node, "ssc")
 				== ssc_num) {
-				ssc->pdev->id = ssc_num;
-				ssc_valid = 1;
+				iter->pdev->id = ssc_num;
+				ssc = iter;
 				break;
 			}
-		} else if (ssc->pdev->id == ssc_num) {
-			ssc_valid = 1;
+		} else if (iter->pdev->id == ssc_num) {
+			ssc = iter;
 			break;
 		}
 	}
 
-	if (!ssc_valid) {
+	if (!ssc) {
 		mutex_unlock(&user_lock);
 		pr_err("ssc: ssc%d platform device is missing\n", ssc_num);
 		return ERR_PTR(-ENODEV);
-- 
2.25.1

[PATCH 3/3] ASoC: atmel-ssc: replace usage of found with dedicated list iterator variable

[Jakob Koschel]

To move the list iterator variable into the list_for_each_entry_*()
macro in the future it should be avoided to use the list iterator
variable after the loop body.

To *never* use the list iterator variable after the loop it was
concluded to use a separate iterator variable instead of a
found boolean [1].

This removes the need to use a found variable and simply checking if
the variable was set, can determine if the break/goto was hit.

Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ [1]
Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com>
---
 drivers/misc/atmel-ssc.c | 19 +++++++++----------
 1 file changed, 9 insertions(+), 10 deletions(-)

diff --git a/drivers/misc/atmel-ssc.c b/drivers/misc/atmel-ssc.c
index d6cd5537126c..343e25555fbb 100644
--- a/drivers/misc/atmel-ssc.c
+++ b/drivers/misc/atmel-ssc.c
@@ -25,25 +25,24 @@ static LIST_HEAD(ssc_list);
 
 struct ssc_device *ssc_request(unsigned int ssc_num)
 {
-	int ssc_valid = 0;
-	struct ssc_device *ssc;
+	struct ssc_device *ssc = NULL, *iter;
 
 	mutex_lock(&user_lock);
-	list_for_each_entry(ssc, &ssc_list, list) {
-		if (ssc->pdev->dev.of_node) {
-			if (of_alias_get_id(ssc->pdev->dev.of_node, "ssc")
+	list_for_each_entry(iter, &ssc_list, list) {
+		if (iter->pdev->dev.of_node) {
+			if (of_alias_get_id(iter->pdev->dev.of_node, "ssc")
 				== ssc_num) {
-				ssc->pdev->id = ssc_num;
-				ssc_valid = 1;
+				iter->pdev->id = ssc_num;
+				ssc = iter;
 				break;
 			}
-		} else if (ssc->pdev->id == ssc_num) {
-			ssc_valid = 1;
+		} else if (iter->pdev->id == ssc_num) {
+			ssc = iter;
 			break;
 		}
 	}
 
-	if (!ssc_valid) {
+	if (!ssc) {
 		mutex_unlock(&user_lock);
 		pr_err("ssc: ssc%d platform device is missing\n", ssc_num);
 		return ERR_PTR(-ENODEV);
-- 
2.25.1


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

Re: [PATCH 2/3] ASoC: sprd: remove check of list iterator against head past the loop body

[Baolin Wang]

On Fri, Apr 1, 2022 at 5:52 AM Jakob Koschel <jakobkoschel@gmail.com> wrote:
>
> When list_for_each_entry() completes the iteration over the whole list
> without breaking the loop, the iterator value will be a bogus pointer
> computed based on the head element.
>
> While it is safe to use the pointer to determine if it was computed
> based on the head element, either with list_entry_is_head() or
> &pos->member == head, using the iterator variable after the loop should
> be avoided.
>
> In preparation to limiting the scope of a list iterator to the list
> traversal loop, use a dedicated pointer to point to the found element [1].
>
> Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ [1]
> Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com>

LGTM. Thanks.
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>

>  sound/soc/sprd/sprd-mcdt.c | 13 ++++++-------
>  1 file changed, 6 insertions(+), 7 deletions(-)
>
> diff --git a/sound/soc/sprd/sprd-mcdt.c b/sound/soc/sprd/sprd-mcdt.c
> index f6a55fa60c1b..6e27789a0df5 100644
> --- a/sound/soc/sprd/sprd-mcdt.c
> +++ b/sound/soc/sprd/sprd-mcdt.c
> @@ -866,20 +866,19 @@ EXPORT_SYMBOL_GPL(sprd_mcdt_chan_dma_disable);
>  struct sprd_mcdt_chan *sprd_mcdt_request_chan(u8 channel,
>                                               enum sprd_mcdt_channel_type type)
>  {
> -       struct sprd_mcdt_chan *temp;
> +       struct sprd_mcdt_chan *temp = NULL;
> +       struct sprd_mcdt_chan *iter;
>
>         mutex_lock(&sprd_mcdt_list_mutex);
>
> -       list_for_each_entry(temp, &sprd_mcdt_chan_list, list) {
> -               if (temp->type == type && temp->id == channel) {
> -                       list_del_init(&temp->list);
> +       list_for_each_entry(iter, &sprd_mcdt_chan_list, list) {
> +               if (iter->type == type && iter->id == channel) {
> +                       list_del_init(&iter->list);
> +                       temp = iter;
>                         break;
>                 }
>         }
>
> -       if (list_entry_is_head(temp, &sprd_mcdt_chan_list, list))
> -               temp = NULL;
> -
>         mutex_unlock(&sprd_mcdt_list_mutex);
>
>         return temp;
> --
> 2.25.1
>


-- 
Baolin Wang

Re: [PATCH 2/3] ASoC: sprd: remove check of list iterator against head past the loop body

[Baolin Wang]

On Fri, Apr 1, 2022 at 5:52 AM Jakob Koschel <jakobkoschel@gmail.com> wrote:
>
> When list_for_each_entry() completes the iteration over the whole list
> without breaking the loop, the iterator value will be a bogus pointer
> computed based on the head element.
>
> While it is safe to use the pointer to determine if it was computed
> based on the head element, either with list_entry_is_head() or
> &pos->member == head, using the iterator variable after the loop should
> be avoided.
>
> In preparation to limiting the scope of a list iterator to the list
> traversal loop, use a dedicated pointer to point to the found element [1].
>
> Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ [1]
> Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com>

LGTM. Thanks.
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>

>  sound/soc/sprd/sprd-mcdt.c | 13 ++++++-------
>  1 file changed, 6 insertions(+), 7 deletions(-)
>
> diff --git a/sound/soc/sprd/sprd-mcdt.c b/sound/soc/sprd/sprd-mcdt.c
> index f6a55fa60c1b..6e27789a0df5 100644
> --- a/sound/soc/sprd/sprd-mcdt.c
> +++ b/sound/soc/sprd/sprd-mcdt.c
> @@ -866,20 +866,19 @@ EXPORT_SYMBOL_GPL(sprd_mcdt_chan_dma_disable);
>  struct sprd_mcdt_chan *sprd_mcdt_request_chan(u8 channel,
>                                               enum sprd_mcdt_channel_type type)
>  {
> -       struct sprd_mcdt_chan *temp;
> +       struct sprd_mcdt_chan *temp = NULL;
> +       struct sprd_mcdt_chan *iter;
>
>         mutex_lock(&sprd_mcdt_list_mutex);
>
> -       list_for_each_entry(temp, &sprd_mcdt_chan_list, list) {
> -               if (temp->type == type && temp->id == channel) {
> -                       list_del_init(&temp->list);
> +       list_for_each_entry(iter, &sprd_mcdt_chan_list, list) {
> +               if (iter->type == type && iter->id == channel) {
> +                       list_del_init(&iter->list);
> +                       temp = iter;
>                         break;
>                 }
>         }
>
> -       if (list_entry_is_head(temp, &sprd_mcdt_chan_list, list))
> -               temp = NULL;
> -
>         mutex_unlock(&sprd_mcdt_list_mutex);
>
>         return temp;
> --
> 2.25.1
>


-- 
Baolin Wang

Re: [PATCH 2/3] ASoC: sprd: remove check of list iterator against head past the loop body

[Baolin Wang]

On Fri, Apr 1, 2022 at 5:52 AM Jakob Koschel <jakobkoschel@gmail.com> wrote:
>
> When list_for_each_entry() completes the iteration over the whole list
> without breaking the loop, the iterator value will be a bogus pointer
> computed based on the head element.
>
> While it is safe to use the pointer to determine if it was computed
> based on the head element, either with list_entry_is_head() or
> &pos->member == head, using the iterator variable after the loop should
> be avoided.
>
> In preparation to limiting the scope of a list iterator to the list
> traversal loop, use a dedicated pointer to point to the found element [1].
>
> Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ [1]
> Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com>

LGTM. Thanks.
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>

>  sound/soc/sprd/sprd-mcdt.c | 13 ++++++-------
>  1 file changed, 6 insertions(+), 7 deletions(-)
>
> diff --git a/sound/soc/sprd/sprd-mcdt.c b/sound/soc/sprd/sprd-mcdt.c
> index f6a55fa60c1b..6e27789a0df5 100644
> --- a/sound/soc/sprd/sprd-mcdt.c
> +++ b/sound/soc/sprd/sprd-mcdt.c
> @@ -866,20 +866,19 @@ EXPORT_SYMBOL_GPL(sprd_mcdt_chan_dma_disable);
>  struct sprd_mcdt_chan *sprd_mcdt_request_chan(u8 channel,
>                                               enum sprd_mcdt_channel_type type)
>  {
> -       struct sprd_mcdt_chan *temp;
> +       struct sprd_mcdt_chan *temp = NULL;
> +       struct sprd_mcdt_chan *iter;
>
>         mutex_lock(&sprd_mcdt_list_mutex);
>
> -       list_for_each_entry(temp, &sprd_mcdt_chan_list, list) {
> -               if (temp->type == type && temp->id == channel) {
> -                       list_del_init(&temp->list);
> +       list_for_each_entry(iter, &sprd_mcdt_chan_list, list) {
> +               if (iter->type == type && iter->id == channel) {
> +                       list_del_init(&iter->list);
> +                       temp = iter;
>                         break;
>                 }
>         }
>
> -       if (list_entry_is_head(temp, &sprd_mcdt_chan_list, list))
> -               temp = NULL;
> -
>         mutex_unlock(&sprd_mcdt_list_mutex);
>
>         return temp;
> --
> 2.25.1
>


-- 
Baolin Wang

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

Re: [PATCH 1/3] ASoC: Intel: catpt: remove check of list iterator against head past the loop body

[Cezary Rojewski]

On 2022-03-31 11:50 PM, Jakob Koschel wrote:
> When list_for_each_entry() completes the iteration over the whole list
> without breaking the loop, the iterator value will be a bogus pointer
> computed based on the head element.
> 
> While it is safe to use the pointer to determine if it was computed
> based on the head element, either with list_entry_is_head() or
> &pos->member == head, using the iterator variable after the loop should
> be avoided.
> 
> In preparation to limiting the scope of a list iterator to the list
> traversal loop, use a dedicated pointer to point to the found element [1].
> 
> Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ [1]
> Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com>

Thank you for taking time and updating catpt-driver along the way.

Acked-by: Cezary Rojewski <cezary.rojewski@intel.com>

> ---
>   sound/soc/intel/catpt/pcm.c | 13 ++++++++-----
>   1 file changed, 8 insertions(+), 5 deletions(-)
> 
> diff --git a/sound/soc/intel/catpt/pcm.c b/sound/soc/intel/catpt/pcm.c
> index a26000cd5ceb..b103b2d4026e 100644
> --- a/sound/soc/intel/catpt/pcm.c
> +++ b/sound/soc/intel/catpt/pcm.c
> @@ -330,7 +330,8 @@ static int catpt_dai_apply_usettings(struct snd_soc_dai *dai,
>   				     struct catpt_stream_runtime *stream)
>   {
>   	struct snd_soc_component *component = dai->component;
> -	struct snd_kcontrol *pos;
> +	struct snd_kcontrol *pos = NULL;
> +	struct snd_kcontrol *iter;
>   	struct catpt_dev *cdev = dev_get_drvdata(dai->dev);
>   	const char *name;
>   	int ret;
> @@ -354,12 +355,14 @@ static int catpt_dai_apply_usettings(struct snd_soc_dai *dai,
>   		return 0;
>   	}
>   
> -	list_for_each_entry(pos, &component->card->snd_card->controls, list) {
> -		if (pos->private_data == component &&
> -		    !strncmp(name, pos->id.name, sizeof(pos->id.name)))
> +	list_for_each_entry(iter, &component->card->snd_card->controls, list) {
> +		if (iter->private_data == component &&
> +		    !strncmp(name, iter->id.name, sizeof(iter->id.name))) {
> +			pos = iter;
>   			break;
> +		}
>   	}
> -	if (list_entry_is_head(pos, &component->card->snd_card->controls, list))
> +	if (!pos)
>   		return -ENOENT;
>   
>   	if (stream->template->type != CATPT_STRM_TYPE_LOOPBACK)
> 
> base-commit: f82da161ea75dc4db21b2499e4b1facd36dab275

Re: [PATCH 1/3] ASoC: Intel: catpt: remove check of list iterator against head past the loop body

[Cezary Rojewski]

On 2022-03-31 11:50 PM, Jakob Koschel wrote:
> When list_for_each_entry() completes the iteration over the whole list
> without breaking the loop, the iterator value will be a bogus pointer
> computed based on the head element.
> 
> While it is safe to use the pointer to determine if it was computed
> based on the head element, either with list_entry_is_head() or
> &pos->member == head, using the iterator variable after the loop should
> be avoided.
> 
> In preparation to limiting the scope of a list iterator to the list
> traversal loop, use a dedicated pointer to point to the found element [1].
> 
> Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ [1]
> Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com>

Thank you for taking time and updating catpt-driver along the way.

Acked-by: Cezary Rojewski <cezary.rojewski@intel.com>

> ---
>   sound/soc/intel/catpt/pcm.c | 13 ++++++++-----
>   1 file changed, 8 insertions(+), 5 deletions(-)
> 
> diff --git a/sound/soc/intel/catpt/pcm.c b/sound/soc/intel/catpt/pcm.c
> index a26000cd5ceb..b103b2d4026e 100644
> --- a/sound/soc/intel/catpt/pcm.c
> +++ b/sound/soc/intel/catpt/pcm.c
> @@ -330,7 +330,8 @@ static int catpt_dai_apply_usettings(struct snd_soc_dai *dai,
>   				     struct catpt_stream_runtime *stream)
>   {
>   	struct snd_soc_component *component = dai->component;
> -	struct snd_kcontrol *pos;
> +	struct snd_kcontrol *pos = NULL;
> +	struct snd_kcontrol *iter;
>   	struct catpt_dev *cdev = dev_get_drvdata(dai->dev);
>   	const char *name;
>   	int ret;
> @@ -354,12 +355,14 @@ static int catpt_dai_apply_usettings(struct snd_soc_dai *dai,
>   		return 0;
>   	}
>   
> -	list_for_each_entry(pos, &component->card->snd_card->controls, list) {
> -		if (pos->private_data == component &&
> -		    !strncmp(name, pos->id.name, sizeof(pos->id.name)))
> +	list_for_each_entry(iter, &component->card->snd_card->controls, list) {
> +		if (iter->private_data == component &&
> +		    !strncmp(name, iter->id.name, sizeof(iter->id.name))) {
> +			pos = iter;
>   			break;
> +		}
>   	}
> -	if (list_entry_is_head(pos, &component->card->snd_card->controls, list))
> +	if (!pos)
>   		return -ENOENT;
>   
>   	if (stream->template->type != CATPT_STRM_TYPE_LOOPBACK)
> 
> base-commit: f82da161ea75dc4db21b2499e4b1facd36dab275

Re: [PATCH 1/3] ASoC: Intel: catpt: remove check of list iterator against head past the loop body

[Cezary Rojewski]

On 2022-03-31 11:50 PM, Jakob Koschel wrote:
> When list_for_each_entry() completes the iteration over the whole list
> without breaking the loop, the iterator value will be a bogus pointer
> computed based on the head element.
> 
> While it is safe to use the pointer to determine if it was computed
> based on the head element, either with list_entry_is_head() or
> &pos->member == head, using the iterator variable after the loop should
> be avoided.
> 
> In preparation to limiting the scope of a list iterator to the list
> traversal loop, use a dedicated pointer to point to the found element [1].
> 
> Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ [1]
> Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com>

Thank you for taking time and updating catpt-driver along the way.

Acked-by: Cezary Rojewski <cezary.rojewski@intel.com>

> ---
>   sound/soc/intel/catpt/pcm.c | 13 ++++++++-----
>   1 file changed, 8 insertions(+), 5 deletions(-)
> 
> diff --git a/sound/soc/intel/catpt/pcm.c b/sound/soc/intel/catpt/pcm.c
> index a26000cd5ceb..b103b2d4026e 100644
> --- a/sound/soc/intel/catpt/pcm.c
> +++ b/sound/soc/intel/catpt/pcm.c
> @@ -330,7 +330,8 @@ static int catpt_dai_apply_usettings(struct snd_soc_dai *dai,
>   				     struct catpt_stream_runtime *stream)
>   {
>   	struct snd_soc_component *component = dai->component;
> -	struct snd_kcontrol *pos;
> +	struct snd_kcontrol *pos = NULL;
> +	struct snd_kcontrol *iter;
>   	struct catpt_dev *cdev = dev_get_drvdata(dai->dev);
>   	const char *name;
>   	int ret;
> @@ -354,12 +355,14 @@ static int catpt_dai_apply_usettings(struct snd_soc_dai *dai,
>   		return 0;
>   	}
>   
> -	list_for_each_entry(pos, &component->card->snd_card->controls, list) {
> -		if (pos->private_data == component &&
> -		    !strncmp(name, pos->id.name, sizeof(pos->id.name)))
> +	list_for_each_entry(iter, &component->card->snd_card->controls, list) {
> +		if (iter->private_data == component &&
> +		    !strncmp(name, iter->id.name, sizeof(iter->id.name))) {
> +			pos = iter;
>   			break;
> +		}
>   	}
> -	if (list_entry_is_head(pos, &component->card->snd_card->controls, list))
> +	if (!pos)
>   		return -ENOENT;
>   
>   	if (stream->template->type != CATPT_STRM_TYPE_LOOPBACK)
> 
> base-commit: f82da161ea75dc4db21b2499e4b1facd36dab275

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

Re: [PATCH 3/3] ASoC: atmel-ssc: replace usage of found with dedicated list iterator variable

[Codrin.Ciubotariu]

On 01.04.2022 00:50, Jakob Koschel wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
> 
> To move the list iterator variable into the list_for_each_entry_*()
> macro in the future it should be avoided to use the list iterator
> variable after the loop body.
> 
> To *never* use the list iterator variable after the loop it was
> concluded to use a separate iterator variable instead of a
> found boolean [1].
> 
> This removes the need to use a found variable and simply checking if
> the variable was set, can determine if the break/goto was hit.
> 
> Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ [1]
> Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com>

Reviewed-by: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>

Thanks!

Re: [PATCH 3/3] ASoC: atmel-ssc: replace usage of found with dedicated list iterator variable

[Codrin.Ciubotariu]

On 01.04.2022 00:50, Jakob Koschel wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
> 
> To move the list iterator variable into the list_for_each_entry_*()
> macro in the future it should be avoided to use the list iterator
> variable after the loop body.
> 
> To *never* use the list iterator variable after the loop it was
> concluded to use a separate iterator variable instead of a
> found boolean [1].
> 
> This removes the need to use a found variable and simply checking if
> the variable was set, can determine if the break/goto was hit.
> 
> Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ [1]
> Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com>

Reviewed-by: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>

Thanks!

Re: [PATCH 3/3] ASoC: atmel-ssc: replace usage of found with dedicated list iterator variable

[Codrin.Ciubotariu]

On 01.04.2022 00:50, Jakob Koschel wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
> 
> To move the list iterator variable into the list_for_each_entry_*()
> macro in the future it should be avoided to use the list iterator
> variable after the loop body.
> 
> To *never* use the list iterator variable after the loop it was
> concluded to use a separate iterator variable instead of a
> found boolean [1].
> 
> This removes the need to use a found variable and simply checking if
> the variable was set, can determine if the break/goto was hit.
> 
> Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ [1]
> Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com>

Reviewed-by: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>

Thanks!
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel