[PATCH 0/3] ASoC: snprintf() usage fixes

[PATCH 0/3] ASoC: snprintf() usage fixes

[Takashi Iwai]

Hi,

this is a series of patches I spotted during debugging other code.
Intel skl and ASoC PCM core invokes succeeding calls of snprintf()
with the incorrect expectation of the return value, which may lead to
a buffer overflow.

The first patch is yet another bug I found during working on this, and
it's rather a real bug that can be seen clearly.


Takashi

===

Takashi Iwai (3):
  ASoC: intel: skl: Fix pin debug prints
  ASoC: intel: skl: Fix possible buffer overflow in debug outputs
  ASoC: pcm: Fix possible buffer overflow in dpcm state sysfs output

 sound/soc/intel/skylake/skl-debug.c | 32 +++++++++++++++++---------------
 sound/soc/soc-pcm.c                 | 16 ++++++++--------
 2 files changed, 25 insertions(+), 23 deletions(-)

-- 
2.16.4

[PATCH 1/3] ASoC: intel: skl: Fix pin debug prints

[Takashi Iwai]

skl_print_pins() loops over all given pins but it overwrites the text
at the very same position while increasing the returned length.
Fix this to show the all pin contents properly.

Fixes: d14700a01f91 ("ASoC: Intel: Skylake: Debugfs facility to dump module config")
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
 sound/soc/intel/skylake/skl-debug.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/sound/soc/intel/skylake/skl-debug.c b/sound/soc/intel/skylake/skl-debug.c
index 3466675f2678..4c1703da1a6d 100644
--- a/sound/soc/intel/skylake/skl-debug.c
+++ b/sound/soc/intel/skylake/skl-debug.c
@@ -34,7 +34,7 @@ static ssize_t skl_print_pins(struct skl_module_pin *m_pin, char *buf,
 	int i;
 	ssize_t ret = 0;
 
-	for (i = 0; i < max_pin; i++)
+	for (i = 0; i < max_pin; i++) {
 		ret += snprintf(buf + size, MOD_BUF - size,
 				"%s %d\n\tModule %d\n\tInstance %d\n\t"
 				"In-used %s\n\tType %s\n"
@@ -45,6 +45,8 @@ static ssize_t skl_print_pins(struct skl_module_pin *m_pin, char *buf,
 				m_pin[i].in_use ? "Used" : "Unused",
 				m_pin[i].is_dynamic ? "Dynamic" : "Static",
 				m_pin[i].pin_state, i);
+		size += ret;
+	}
 	return ret;
 }
 
-- 
2.16.4

[PATCH 2/3] ASoC: intel: skl: Fix possible buffer overflow in debug outputs

[Takashi Iwai]

The debugfs output of intel skl driver writes strings with multiple
snprintf() calls with the fixed size.  This was supposed to avoid the
buffer overflow but actually it still would, because snprintf()
returns the expected size to be output, not the actual output size.

Fix it by replacing snprintf() calls with scnprintf().

Fixes: d14700a01f91 ("ASoC: Intel: Skylake: Debugfs facility to dump module config")
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
 sound/soc/intel/skylake/skl-debug.c | 28 ++++++++++++++--------------
 1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/sound/soc/intel/skylake/skl-debug.c b/sound/soc/intel/skylake/skl-debug.c
index 4c1703da1a6d..a15aa2ffa681 100644
--- a/sound/soc/intel/skylake/skl-debug.c
+++ b/sound/soc/intel/skylake/skl-debug.c
@@ -35,7 +35,7 @@ static ssize_t skl_print_pins(struct skl_module_pin *m_pin, char *buf,
 	ssize_t ret = 0;
 
 	for (i = 0; i < max_pin; i++) {
-		ret += snprintf(buf + size, MOD_BUF - size,
+		ret += scnprintf(buf + size, MOD_BUF - size,
 				"%s %d\n\tModule %d\n\tInstance %d\n\t"
 				"In-used %s\n\tType %s\n"
 				"\tState %d\n\tIndex %d\n",
@@ -53,7 +53,7 @@ static ssize_t skl_print_pins(struct skl_module_pin *m_pin, char *buf,
 static ssize_t skl_print_fmt(struct skl_module_fmt *fmt, char *buf,
 					ssize_t size, bool direction)
 {
-	return snprintf(buf + size, MOD_BUF - size,
+	return scnprintf(buf + size, MOD_BUF - size,
 			"%s\n\tCh %d\n\tFreq %d\n\tBit depth %d\n\t"
 			"Valid bit depth %d\n\tCh config %#x\n\tInterleaving %d\n\t"
 			"Sample Type %d\n\tCh Map %#x\n",
@@ -77,16 +77,16 @@ static ssize_t module_read(struct file *file, char __user *user_buf,
 	if (!buf)
 		return -ENOMEM;
 
-	ret = snprintf(buf, MOD_BUF, "Module:\n\tUUID %pUL\n\tModule id %d\n"
+	ret = scnprintf(buf, MOD_BUF, "Module:\n\tUUID %pUL\n\tModule id %d\n"
 			"\tInstance id %d\n\tPvt_id %d\n", mconfig->guid,
 			mconfig->id.module_id, mconfig->id.instance_id,
 			mconfig->id.pvt_id);
 
-	ret += snprintf(buf + ret, MOD_BUF - ret,
+	ret += scnprintf(buf + ret, MOD_BUF - ret,
 			"Resources:\n\tCPC %#x\n\tIBS %#x\n\tOBS %#x\t\n",
 			res->cpc, res->ibs, res->obs);
 
-	ret += snprintf(buf + ret, MOD_BUF - ret,
+	ret += scnprintf(buf + ret, MOD_BUF - ret,
 			"Module data:\n\tCore %d\n\tIn queue %d\n\t"
 			"Out queue %d\n\tType %s\n",
 			mconfig->core_id, mconfig->max_in_queue,
@@ -96,38 +96,38 @@ static ssize_t module_read(struct file *file, char __user *user_buf,
 	ret += skl_print_fmt(mconfig->in_fmt, buf, ret, true);
 	ret += skl_print_fmt(mconfig->out_fmt, buf, ret, false);
 
-	ret += snprintf(buf + ret, MOD_BUF - ret,
+	ret += scnprintf(buf + ret, MOD_BUF - ret,
 			"Fixup:\n\tParams %#x\n\tConverter %#x\n",
 			mconfig->params_fixup, mconfig->converter);
 
-	ret += snprintf(buf + ret, MOD_BUF - ret,
+	ret += scnprintf(buf + ret, MOD_BUF - ret,
 			"Module Gateway:\n\tType %#x\n\tVbus %#x\n\tHW conn %#x\n\tSlot %#x\n",
 			mconfig->dev_type, mconfig->vbus_id,
 			mconfig->hw_conn_type, mconfig->time_slot);
 
-	ret += snprintf(buf + ret, MOD_BUF - ret,
+	ret += scnprintf(buf + ret, MOD_BUF - ret,
 			"Pipeline:\n\tID %d\n\tPriority %d\n\tConn Type %d\n\t"
 			"Pages %#x\n", mconfig->pipe->ppl_id,
 			mconfig->pipe->pipe_priority, mconfig->pipe->conn_type,
 			mconfig->pipe->memory_pages);
 
-	ret += snprintf(buf + ret, MOD_BUF - ret,
+	ret += scnprintf(buf + ret, MOD_BUF - ret,
 			"\tParams:\n\t\tHost DMA %d\n\t\tLink DMA %d\n",
 			mconfig->pipe->p_params->host_dma_id,
 			mconfig->pipe->p_params->link_dma_id);
 
-	ret += snprintf(buf + ret, MOD_BUF - ret,
+	ret += scnprintf(buf + ret, MOD_BUF - ret,
 			"\tPCM params:\n\t\tCh %d\n\t\tFreq %d\n\t\tFormat %d\n",
 			mconfig->pipe->p_params->ch,
 			mconfig->pipe->p_params->s_freq,
 			mconfig->pipe->p_params->s_fmt);
 
-	ret += snprintf(buf + ret, MOD_BUF - ret,
+	ret += scnprintf(buf + ret, MOD_BUF - ret,
 			"\tLink %#x\n\tStream %#x\n",
 			mconfig->pipe->p_params->linktype,
 			mconfig->pipe->p_params->stream);
 
-	ret += snprintf(buf + ret, MOD_BUF - ret,
+	ret += scnprintf(buf + ret, MOD_BUF - ret,
 			"\tState %d\n\tPassthru %s\n",
 			mconfig->pipe->state,
 			mconfig->pipe->passthru ? "true" : "false");
@@ -137,7 +137,7 @@ static ssize_t module_read(struct file *file, char __user *user_buf,
 	ret += skl_print_pins(mconfig->m_out_pin, buf,
 			mconfig->max_out_queue, ret, false);
 
-	ret += snprintf(buf + ret, MOD_BUF - ret,
+	ret += scnprintf(buf + ret, MOD_BUF - ret,
 			"Other:\n\tDomain %d\n\tHomogeneous Input %s\n\t"
 			"Homogeneous Output %s\n\tIn Queue Mask %d\n\t"
 			"Out Queue Mask %d\n\tDMA ID %d\n\tMem Pages %d\n\t"
@@ -193,7 +193,7 @@ static ssize_t fw_softreg_read(struct file *file, char __user *user_buf,
 		__ioread32_copy(d->fw_read_buff, fw_reg_addr, w0_stat_sz >> 2);
 
 	for (offset = 0; offset < FW_REG_SIZE; offset += 16) {
-		ret += snprintf(tmp + ret, FW_REG_BUF - ret, "%#.4x: ", offset);
+		ret += scnprintf(tmp + ret, FW_REG_BUF - ret, "%#.4x: ", offset);
 		hex_dump_to_buffer(d->fw_read_buff + offset, 16, 16, 4,
 				   tmp + ret, FW_REG_BUF - ret, 0);
 		ret += strlen(tmp + ret);
-- 
2.16.4

[PATCH 3/3] ASoC: pcm: Fix possible buffer overflow in dpcm state sysfs output

[Takashi Iwai]

dpcm_show_state() invokes multiple snprintf() calls to concatenate
formatted strings on the fixed size buffer.  The usage of snprintf()
is supposed for avoiding the buffer overflow, but it doesn't work as
expected because snprintf() doesn't return the actual output size but
the size to be written.

Fix this bug by replacing all snprintf() calls with scnprintf()
calls.

Fixes: f86dcef87b77 ("ASoC: dpcm: Add debugFS support for DPCM")
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
 sound/soc/soc-pcm.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/sound/soc/soc-pcm.c b/sound/soc/soc-pcm.c
index ff1b7c7078e5..296ba8912e1a 100644
--- a/sound/soc/soc-pcm.c
+++ b/sound/soc/soc-pcm.c
@@ -3171,16 +3171,16 @@ static ssize_t dpcm_show_state(struct snd_soc_pcm_runtime *fe,
 	unsigned long flags;
 
 	/* FE state */
-	offset += snprintf(buf + offset, size - offset,
+	offset += scnprintf(buf + offset, size - offset,
 			"[%s - %s]\n", fe->dai_link->name,
 			stream ? "Capture" : "Playback");
 
-	offset += snprintf(buf + offset, size - offset, "State: %s\n",
+	offset += scnprintf(buf + offset, size - offset, "State: %s\n",
 	                dpcm_state_string(fe->dpcm[stream].state));
 
 	if ((fe->dpcm[stream].state >= SND_SOC_DPCM_STATE_HW_PARAMS) &&
 	    (fe->dpcm[stream].state <= SND_SOC_DPCM_STATE_STOP))
-		offset += snprintf(buf + offset, size - offset,
+		offset += scnprintf(buf + offset, size - offset,
 				"Hardware Params: "
 				"Format = %s, Channels = %d, Rate = %d\n",
 				snd_pcm_format_name(params_format(params)),
@@ -3188,10 +3188,10 @@ static ssize_t dpcm_show_state(struct snd_soc_pcm_runtime *fe,
 				params_rate(params));
 
 	/* BEs state */
-	offset += snprintf(buf + offset, size - offset, "Backends:\n");
+	offset += scnprintf(buf + offset, size - offset, "Backends:\n");
 
 	if (list_empty(&fe->dpcm[stream].be_clients)) {
-		offset += snprintf(buf + offset, size - offset,
+		offset += scnprintf(buf + offset, size - offset,
 				" No active DSP links\n");
 		goto out;
 	}
@@ -3201,16 +3201,16 @@ static ssize_t dpcm_show_state(struct snd_soc_pcm_runtime *fe,
 		struct snd_soc_pcm_runtime *be = dpcm->be;
 		params = &dpcm->hw_params;
 
-		offset += snprintf(buf + offset, size - offset,
+		offset += scnprintf(buf + offset, size - offset,
 				"- %s\n", be->dai_link->name);
 
-		offset += snprintf(buf + offset, size - offset,
+		offset += scnprintf(buf + offset, size - offset,
 				"   State: %s\n",
 				dpcm_state_string(be->dpcm[stream].state));
 
 		if ((be->dpcm[stream].state >= SND_SOC_DPCM_STATE_HW_PARAMS) &&
 		    (be->dpcm[stream].state <= SND_SOC_DPCM_STATE_STOP))
-			offset += snprintf(buf + offset, size - offset,
+			offset += scnprintf(buf + offset, size - offset,
 				"   Hardware Params: "
 				"Format = %s, Channels = %d, Rate = %d\n",
 				snd_pcm_format_name(params_format(params)),
-- 
2.16.4

Re: [PATCH 0/3] ASoC: snprintf() usage fixes

[Cezary Rojewski]

On 2020-02-18 12:17, Takashi Iwai wrote:
> Hi,
> 
> this is a series of patches I spotted during debugging other code.
> Intel skl and ASoC PCM core invokes succeeding calls of snprintf()
> with the incorrect expectation of the return value, which may lead to
> a buffer overflow.
> 
> The first patch is yet another bug I found during working on this, and
> it's rather a real bug that can be seen clearly.
> 
> 
> Takashi
> 
> ===
> 
> Takashi Iwai (3):
>    ASoC: intel: skl: Fix pin debug prints
>    ASoC: intel: skl: Fix possible buffer overflow in debug outputs
>    ASoC: pcm: Fix possible buffer overflow in dpcm state sysfs output

Thank you, Takashi for the fixes.

s/skl/skylake/g but I don't mind the shortcut usage at all.
For the /intel/skylake patches:

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

Applied "ASoC: pcm: Fix possible buffer overflow in dpcm state sysfs output" to the asoc tree

[Mark Brown]

The patch

   ASoC: pcm: Fix possible buffer overflow in dpcm state sysfs output

has been applied to the asoc tree at

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git 

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.  

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

From 6c89ffea60aa3b2a33ae7987de1e84bfb89e4c9e Mon Sep 17 00:00:00 2001
From: Takashi Iwai <tiwai@suse.de>
Date: Tue, 18 Feb 2020 12:17:37 +0100
Subject: [PATCH] ASoC: pcm: Fix possible buffer overflow in dpcm state sysfs
 output

dpcm_show_state() invokes multiple snprintf() calls to concatenate
formatted strings on the fixed size buffer.  The usage of snprintf()
is supposed for avoiding the buffer overflow, but it doesn't work as
expected because snprintf() doesn't return the actual output size but
the size to be written.

Fix this bug by replacing all snprintf() calls with scnprintf()
calls.

Fixes: f86dcef87b77 ("ASoC: dpcm: Add debugFS support for DPCM")
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Cezary Rojewski <cezary.rojewski@intel.com>
Link: https://lore.kernel.org/r/20200218111737.14193-4-tiwai@suse.de
Signed-off-by: Mark Brown <broonie@kernel.org>
---
 sound/soc/soc-pcm.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/sound/soc/soc-pcm.c b/sound/soc/soc-pcm.c
index e66ac9ce321b..42fb03a99cb1 100644
--- a/sound/soc/soc-pcm.c
+++ b/sound/soc/soc-pcm.c
@@ -3171,16 +3171,16 @@ static ssize_t dpcm_show_state(struct snd_soc_pcm_runtime *fe,
 	unsigned long flags;
 
 	/* FE state */
-	offset += snprintf(buf + offset, size - offset,
+	offset += scnprintf(buf + offset, size - offset,
 			"[%s - %s]\n", fe->dai_link->name,
 			stream ? "Capture" : "Playback");
 
-	offset += snprintf(buf + offset, size - offset, "State: %s\n",
+	offset += scnprintf(buf + offset, size - offset, "State: %s\n",
 	                dpcm_state_string(fe->dpcm[stream].state));
 
 	if ((fe->dpcm[stream].state >= SND_SOC_DPCM_STATE_HW_PARAMS) &&
 	    (fe->dpcm[stream].state <= SND_SOC_DPCM_STATE_STOP))
-		offset += snprintf(buf + offset, size - offset,
+		offset += scnprintf(buf + offset, size - offset,
 				"Hardware Params: "
 				"Format = %s, Channels = %d, Rate = %d\n",
 				snd_pcm_format_name(params_format(params)),
@@ -3188,10 +3188,10 @@ static ssize_t dpcm_show_state(struct snd_soc_pcm_runtime *fe,
 				params_rate(params));
 
 	/* BEs state */
-	offset += snprintf(buf + offset, size - offset, "Backends:\n");
+	offset += scnprintf(buf + offset, size - offset, "Backends:\n");
 
 	if (list_empty(&fe->dpcm[stream].be_clients)) {
-		offset += snprintf(buf + offset, size - offset,
+		offset += scnprintf(buf + offset, size - offset,
 				" No active DSP links\n");
 		goto out;
 	}
@@ -3201,16 +3201,16 @@ static ssize_t dpcm_show_state(struct snd_soc_pcm_runtime *fe,
 		struct snd_soc_pcm_runtime *be = dpcm->be;
 		params = &dpcm->hw_params;
 
-		offset += snprintf(buf + offset, size - offset,
+		offset += scnprintf(buf + offset, size - offset,
 				"- %s\n", be->dai_link->name);
 
-		offset += snprintf(buf + offset, size - offset,
+		offset += scnprintf(buf + offset, size - offset,
 				"   State: %s\n",
 				dpcm_state_string(be->dpcm[stream].state));
 
 		if ((be->dpcm[stream].state >= SND_SOC_DPCM_STATE_HW_PARAMS) &&
 		    (be->dpcm[stream].state <= SND_SOC_DPCM_STATE_STOP))
-			offset += snprintf(buf + offset, size - offset,
+			offset += scnprintf(buf + offset, size - offset,
 				"   Hardware Params: "
 				"Format = %s, Channels = %d, Rate = %d\n",
 				snd_pcm_format_name(params_format(params)),
-- 
2.20.1

Applied "ASoC: intel: skl: Fix possible buffer overflow in debug outputs" to the asoc tree

[Mark Brown]

The patch

   ASoC: intel: skl: Fix possible buffer overflow in debug outputs

has been applied to the asoc tree at

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git 

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.  

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

From 549cd0ba04dcfe340c349cd983bd440480fae8ee Mon Sep 17 00:00:00 2001
From: Takashi Iwai <tiwai@suse.de>
Date: Tue, 18 Feb 2020 12:17:36 +0100
Subject: [PATCH] ASoC: intel: skl: Fix possible buffer overflow in debug
 outputs

The debugfs output of intel skl driver writes strings with multiple
snprintf() calls with the fixed size.  This was supposed to avoid the
buffer overflow but actually it still would, because snprintf()
returns the expected size to be output, not the actual output size.

Fix it by replacing snprintf() calls with scnprintf().

Fixes: d14700a01f91 ("ASoC: Intel: Skylake: Debugfs facility to dump module config")
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Cezary Rojewski <cezary.rojewski@intel.com>
Link: https://lore.kernel.org/r/20200218111737.14193-3-tiwai@suse.de
Signed-off-by: Mark Brown <broonie@kernel.org>
---
 sound/soc/intel/skylake/skl-debug.c | 28 ++++++++++++++--------------
 1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/sound/soc/intel/skylake/skl-debug.c b/sound/soc/intel/skylake/skl-debug.c
index 4c1703da1a6d..a15aa2ffa681 100644
--- a/sound/soc/intel/skylake/skl-debug.c
+++ b/sound/soc/intel/skylake/skl-debug.c
@@ -35,7 +35,7 @@ static ssize_t skl_print_pins(struct skl_module_pin *m_pin, char *buf,
 	ssize_t ret = 0;
 
 	for (i = 0; i < max_pin; i++) {
-		ret += snprintf(buf + size, MOD_BUF - size,
+		ret += scnprintf(buf + size, MOD_BUF - size,
 				"%s %d\n\tModule %d\n\tInstance %d\n\t"
 				"In-used %s\n\tType %s\n"
 				"\tState %d\n\tIndex %d\n",
@@ -53,7 +53,7 @@ static ssize_t skl_print_pins(struct skl_module_pin *m_pin, char *buf,
 static ssize_t skl_print_fmt(struct skl_module_fmt *fmt, char *buf,
 					ssize_t size, bool direction)
 {
-	return snprintf(buf + size, MOD_BUF - size,
+	return scnprintf(buf + size, MOD_BUF - size,
 			"%s\n\tCh %d\n\tFreq %d\n\tBit depth %d\n\t"
 			"Valid bit depth %d\n\tCh config %#x\n\tInterleaving %d\n\t"
 			"Sample Type %d\n\tCh Map %#x\n",
@@ -77,16 +77,16 @@ static ssize_t module_read(struct file *file, char __user *user_buf,
 	if (!buf)
 		return -ENOMEM;
 
-	ret = snprintf(buf, MOD_BUF, "Module:\n\tUUID %pUL\n\tModule id %d\n"
+	ret = scnprintf(buf, MOD_BUF, "Module:\n\tUUID %pUL\n\tModule id %d\n"
 			"\tInstance id %d\n\tPvt_id %d\n", mconfig->guid,
 			mconfig->id.module_id, mconfig->id.instance_id,
 			mconfig->id.pvt_id);
 
-	ret += snprintf(buf + ret, MOD_BUF - ret,
+	ret += scnprintf(buf + ret, MOD_BUF - ret,
 			"Resources:\n\tCPC %#x\n\tIBS %#x\n\tOBS %#x\t\n",
 			res->cpc, res->ibs, res->obs);
 
-	ret += snprintf(buf + ret, MOD_BUF - ret,
+	ret += scnprintf(buf + ret, MOD_BUF - ret,
 			"Module data:\n\tCore %d\n\tIn queue %d\n\t"
 			"Out queue %d\n\tType %s\n",
 			mconfig->core_id, mconfig->max_in_queue,
@@ -96,38 +96,38 @@ static ssize_t module_read(struct file *file, char __user *user_buf,
 	ret += skl_print_fmt(mconfig->in_fmt, buf, ret, true);
 	ret += skl_print_fmt(mconfig->out_fmt, buf, ret, false);
 
-	ret += snprintf(buf + ret, MOD_BUF - ret,
+	ret += scnprintf(buf + ret, MOD_BUF - ret,
 			"Fixup:\n\tParams %#x\n\tConverter %#x\n",
 			mconfig->params_fixup, mconfig->converter);
 
-	ret += snprintf(buf + ret, MOD_BUF - ret,
+	ret += scnprintf(buf + ret, MOD_BUF - ret,
 			"Module Gateway:\n\tType %#x\n\tVbus %#x\n\tHW conn %#x\n\tSlot %#x\n",
 			mconfig->dev_type, mconfig->vbus_id,
 			mconfig->hw_conn_type, mconfig->time_slot);
 
-	ret += snprintf(buf + ret, MOD_BUF - ret,
+	ret += scnprintf(buf + ret, MOD_BUF - ret,
 			"Pipeline:\n\tID %d\n\tPriority %d\n\tConn Type %d\n\t"
 			"Pages %#x\n", mconfig->pipe->ppl_id,
 			mconfig->pipe->pipe_priority, mconfig->pipe->conn_type,
 			mconfig->pipe->memory_pages);
 
-	ret += snprintf(buf + ret, MOD_BUF - ret,
+	ret += scnprintf(buf + ret, MOD_BUF - ret,
 			"\tParams:\n\t\tHost DMA %d\n\t\tLink DMA %d\n",
 			mconfig->pipe->p_params->host_dma_id,
 			mconfig->pipe->p_params->link_dma_id);
 
-	ret += snprintf(buf + ret, MOD_BUF - ret,
+	ret += scnprintf(buf + ret, MOD_BUF - ret,
 			"\tPCM params:\n\t\tCh %d\n\t\tFreq %d\n\t\tFormat %d\n",
 			mconfig->pipe->p_params->ch,
 			mconfig->pipe->p_params->s_freq,
 			mconfig->pipe->p_params->s_fmt);
 
-	ret += snprintf(buf + ret, MOD_BUF - ret,
+	ret += scnprintf(buf + ret, MOD_BUF - ret,
 			"\tLink %#x\n\tStream %#x\n",
 			mconfig->pipe->p_params->linktype,
 			mconfig->pipe->p_params->stream);
 
-	ret += snprintf(buf + ret, MOD_BUF - ret,
+	ret += scnprintf(buf + ret, MOD_BUF - ret,
 			"\tState %d\n\tPassthru %s\n",
 			mconfig->pipe->state,
 			mconfig->pipe->passthru ? "true" : "false");
@@ -137,7 +137,7 @@ static ssize_t module_read(struct file *file, char __user *user_buf,
 	ret += skl_print_pins(mconfig->m_out_pin, buf,
 			mconfig->max_out_queue, ret, false);
 
-	ret += snprintf(buf + ret, MOD_BUF - ret,
+	ret += scnprintf(buf + ret, MOD_BUF - ret,
 			"Other:\n\tDomain %d\n\tHomogeneous Input %s\n\t"
 			"Homogeneous Output %s\n\tIn Queue Mask %d\n\t"
 			"Out Queue Mask %d\n\tDMA ID %d\n\tMem Pages %d\n\t"
@@ -193,7 +193,7 @@ static ssize_t fw_softreg_read(struct file *file, char __user *user_buf,
 		__ioread32_copy(d->fw_read_buff, fw_reg_addr, w0_stat_sz >> 2);
 
 	for (offset = 0; offset < FW_REG_SIZE; offset += 16) {
-		ret += snprintf(tmp + ret, FW_REG_BUF - ret, "%#.4x: ", offset);
+		ret += scnprintf(tmp + ret, FW_REG_BUF - ret, "%#.4x: ", offset);
 		hex_dump_to_buffer(d->fw_read_buff + offset, 16, 16, 4,
 				   tmp + ret, FW_REG_BUF - ret, 0);
 		ret += strlen(tmp + ret);
-- 
2.20.1

Applied "ASoC: intel: skl: Fix pin debug prints" to the asoc tree

[Mark Brown]

The patch

   ASoC: intel: skl: Fix pin debug prints

has been applied to the asoc tree at

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git 

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.  

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

From 64bbacc5f08c01954890981c63de744df1f29a30 Mon Sep 17 00:00:00 2001
From: Takashi Iwai <tiwai@suse.de>
Date: Tue, 18 Feb 2020 12:17:35 +0100
Subject: [PATCH] ASoC: intel: skl: Fix pin debug prints

skl_print_pins() loops over all given pins but it overwrites the text
at the very same position while increasing the returned length.
Fix this to show the all pin contents properly.

Fixes: d14700a01f91 ("ASoC: Intel: Skylake: Debugfs facility to dump module config")
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Cezary Rojewski <cezary.rojewski@intel.com>
Link: https://lore.kernel.org/r/20200218111737.14193-2-tiwai@suse.de
Signed-off-by: Mark Brown <broonie@kernel.org>
---
 sound/soc/intel/skylake/skl-debug.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/sound/soc/intel/skylake/skl-debug.c b/sound/soc/intel/skylake/skl-debug.c
index 3466675f2678..4c1703da1a6d 100644
--- a/sound/soc/intel/skylake/skl-debug.c
+++ b/sound/soc/intel/skylake/skl-debug.c
@@ -34,7 +34,7 @@ static ssize_t skl_print_pins(struct skl_module_pin *m_pin, char *buf,
 	int i;
 	ssize_t ret = 0;
 
-	for (i = 0; i < max_pin; i++)
+	for (i = 0; i < max_pin; i++) {
 		ret += snprintf(buf + size, MOD_BUF - size,
 				"%s %d\n\tModule %d\n\tInstance %d\n\t"
 				"In-used %s\n\tType %s\n"
@@ -45,6 +45,8 @@ static ssize_t skl_print_pins(struct skl_module_pin *m_pin, char *buf,
 				m_pin[i].in_use ? "Used" : "Unused",
 				m_pin[i].is_dynamic ? "Dynamic" : "Static",
 				m_pin[i].pin_state, i);
+		size += ret;
+	}
 	return ret;
 }
 
-- 
2.20.1