[PATCH net-next 0/4] s390/net: updates 2023-06-10

[PATCH net-next 0/4] s390/net: updates 2023-06-10

[Alexandra Winter]

Please apply the following patch series for s390's ctcm and lcs drivers
to netdev's net-next tree.

Just maintenance patches, no functional changes.

Thanks,
Alexandra

Thorsten Winkler (4):
  s390/lcs: Convert sysfs sprintf to sysfs_emit
  s390/lcs: Convert sprintf to scnprintf
  s390/ctcm: Convert sysfs sprintf to sysfs_emit
  s390/ctcm: Convert sprintf/snprintf to scnprintf

 drivers/s390/net/ctcm_dbug.c  |  2 +-
 drivers/s390/net/ctcm_main.c  |  6 ++---
 drivers/s390/net/ctcm_main.h  |  1 +
 drivers/s390/net/ctcm_mpc.c   | 18 ++++++++------
 drivers/s390/net/ctcm_sysfs.c | 46 +++++++++++++++++------------------
 drivers/s390/net/lcs.c        | 13 +++++-----
 drivers/s390/net/lcs.h        |  2 +-
 7 files changed, 46 insertions(+), 42 deletions(-)

-- 
2.39.2

[PATCH net-next 1/4] s390/lcs: Convert sysfs sprintf to sysfs_emit

[Alexandra Winter]

From: Thorsten Winkler <twinkler@linux.ibm.com>

Following the advice of the Documentation/filesystems/sysfs.rst.
All sysfs related show()-functions should only use sysfs_emit() or
sysfs_emit_at() when formatting the value to be returned to user space.

While at it, follow Linux kernel coding style and unify indentation

Reported-by: Jules Irenge <jbi.octave@gmail.com>
Reported-by: Joe Perches <joe@perches.com>
Reviewed-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: Thorsten Winkler <twinkler@linux.ibm.com>
Signed-off-by: Alexandra Winter <wintera@linux.ibm.com>
---
 drivers/s390/net/lcs.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/s390/net/lcs.c b/drivers/s390/net/lcs.c
index 84c8981317b4..bd3d788e5f2d 100644
--- a/drivers/s390/net/lcs.c
+++ b/drivers/s390/net/lcs.c
@@ -1901,14 +1901,14 @@ lcs_open_device(struct net_device *dev)
 static ssize_t
 lcs_portno_show (struct device *dev, struct device_attribute *attr, char *buf)
 {
-        struct lcs_card *card;
+	struct lcs_card *card;
 
 	card = dev_get_drvdata(dev);
 
-        if (!card)
-                return 0;
+	if (!card)
+		return 0;
 
-        return sprintf(buf, "%d\n", card->portno);
+	return sysfs_emit(buf, "%d\n", card->portno);
 }
 
 /*
@@ -1958,7 +1958,8 @@ lcs_type_show(struct device *dev, struct device_attribute *attr, char *buf)
 	if (!cgdev)
 		return -ENODEV;
 
-	return sprintf(buf, "%s\n", lcs_type[cgdev->cdev[0]->id.driver_info]);
+	return sysfs_emit(buf, "%s\n",
+			  lcs_type[cgdev->cdev[0]->id.driver_info]);
 }
 
 static DEVICE_ATTR(type, 0444, lcs_type_show, NULL);
@@ -1970,7 +1971,7 @@ lcs_timeout_show(struct device *dev, struct device_attribute *attr, char *buf)
 
 	card = dev_get_drvdata(dev);
 
-	return card ? sprintf(buf, "%u\n", card->lancmd_timeout) : 0;
+	return card ? sysfs_emit(buf, "%u\n", card->lancmd_timeout) : 0;
 }
 
 static ssize_t
-- 
2.39.2

[PATCH net-next 2/4] s390/lcs: Convert sprintf to scnprintf

[Alexandra Winter]

From: Thorsten Winkler <twinkler@linux.ibm.com>

This LWN article explains the rationale for this change
https: //lwn.net/Articles/69419/
Ie. snprintf() returns what *would* be the resulting length,
while scnprintf() returns the actual length.

Reported-by: Jules Irenge <jbi.octave@gmail.com>
Reviewed-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: Thorsten Winkler <twinkler@linux.ibm.com>
Signed-off-by: Alexandra Winter <wintera@linux.ibm.com>
---
 drivers/s390/net/lcs.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/s390/net/lcs.h b/drivers/s390/net/lcs.h
index bd52caa3b11b..a2699b70b050 100644
--- a/drivers/s390/net/lcs.h
+++ b/drivers/s390/net/lcs.h
@@ -21,7 +21,7 @@ do { \
 #define LCS_DBF_TEXT_(level,name,text...) \
 	do { \
 		if (debug_level_enabled(lcs_dbf_##name, level)) { \
-			sprintf(debug_buffer, text); \
+			scnprintf(debug_buffer, sizeof(debug_buffer), text); \
 			debug_text_event(lcs_dbf_##name, level, debug_buffer); \
 		} \
 	} while (0)
-- 
2.39.2

[PATCH net-next 3/4] s390/ctcm: Convert sysfs sprintf to sysfs_emit

[Alexandra Winter]

From: Thorsten Winkler <twinkler@linux.ibm.com>

Following the advice of the Documentation/filesystems/sysfs.rst.
All sysfs related show()-functions should only use sysfs_emit() or
sysfs_emit_at() when formatting the value to be returned to user space.

Reviewed-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: Thorsten Winkler <twinkler@linux.ibm.com>
Signed-off-by: Alexandra Winter <wintera@linux.ibm.com>
---
 drivers/s390/net/ctcm_sysfs.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/s390/net/ctcm_sysfs.c b/drivers/s390/net/ctcm_sysfs.c
index e3813a7aa5e6..98680c2cc4e4 100644
--- a/drivers/s390/net/ctcm_sysfs.c
+++ b/drivers/s390/net/ctcm_sysfs.c
@@ -28,7 +28,7 @@ static ssize_t ctcm_buffer_show(struct device *dev,
 
 	if (!priv)
 		return -ENODEV;
-	return sprintf(buf, "%d\n", priv->buffer_size);
+	return sysfs_emit(buf, "%d\n", priv->buffer_size);
 }
 
 static ssize_t ctcm_buffer_write(struct device *dev,
@@ -120,7 +120,7 @@ static ssize_t stats_show(struct device *dev,
 	if (!priv || gdev->state != CCWGROUP_ONLINE)
 		return -ENODEV;
 	ctcm_print_statistics(priv);
-	return sprintf(buf, "0\n");
+	return sysfs_emit(buf, "0\n");
 }
 
 static ssize_t stats_write(struct device *dev, struct device_attribute *attr,
@@ -142,7 +142,7 @@ static ssize_t ctcm_proto_show(struct device *dev,
 	if (!priv)
 		return -ENODEV;
 
-	return sprintf(buf, "%d\n", priv->protocol);
+	return sysfs_emit(buf, "%d\n", priv->protocol);
 }
 
 static ssize_t ctcm_proto_store(struct device *dev,
@@ -184,8 +184,8 @@ static ssize_t ctcm_type_show(struct device *dev,
 	if (!cgdev)
 		return -ENODEV;
 
-	return sprintf(buf, "%s\n",
-			ctcm_type[cgdev->cdev[0]->id.driver_info]);
+	return sysfs_emit(buf, "%s\n",
+			  ctcm_type[cgdev->cdev[0]->id.driver_info]);
 }
 
 static DEVICE_ATTR(buffer, 0644, ctcm_buffer_show, ctcm_buffer_write);
-- 
2.39.2

[PATCH net-next 4/4] s390/ctcm: Convert sprintf/snprintf to scnprintf

[Alexandra Winter]

From: Thorsten Winkler <twinkler@linux.ibm.com>

This LWN article explains the rationale for this change
https: //lwn.net/Articles/69419/
Ie. snprintf() returns what *would* be the resulting length,
while scnprintf() returns the actual length.

Note that ctcm_print_statistics() writes the data into the kernel log
and is therefore not suitable for sysfs_emit(). Observable behavior is
not changed, as there may be dependencies.

Reviewed-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: Thorsten Winkler <twinkler@linux.ibm.com>
Signed-off-by: Alexandra Winter <wintera@linux.ibm.com>
---
 drivers/s390/net/ctcm_dbug.c  |  2 +-
 drivers/s390/net/ctcm_main.c  |  6 +++---
 drivers/s390/net/ctcm_main.h  |  1 +
 drivers/s390/net/ctcm_mpc.c   | 18 ++++++++++--------
 drivers/s390/net/ctcm_sysfs.c | 36 +++++++++++++++++------------------
 5 files changed, 33 insertions(+), 30 deletions(-)

diff --git a/drivers/s390/net/ctcm_dbug.c b/drivers/s390/net/ctcm_dbug.c
index f7ec51db3cd6..b6f0e2f114b4 100644
--- a/drivers/s390/net/ctcm_dbug.c
+++ b/drivers/s390/net/ctcm_dbug.c
@@ -70,7 +70,7 @@ void ctcm_dbf_longtext(enum ctcm_dbf_names dbf_nix, int level, char *fmt, ...)
 	if (!debug_level_enabled(ctcm_dbf[dbf_nix].id, level))
 		return;
 	va_start(args, fmt);
-	vsnprintf(dbf_txt_buf, sizeof(dbf_txt_buf), fmt, args);
+	vscnprintf(dbf_txt_buf, sizeof(dbf_txt_buf), fmt, args);
 	va_end(args);
 
 	debug_text_event(ctcm_dbf[dbf_nix].id, level, dbf_txt_buf);
diff --git a/drivers/s390/net/ctcm_main.c b/drivers/s390/net/ctcm_main.c
index e0fdd54bfeb7..79fac5314e67 100644
--- a/drivers/s390/net/ctcm_main.c
+++ b/drivers/s390/net/ctcm_main.c
@@ -1340,7 +1340,7 @@ static int add_channel(struct ccw_device *cdev, enum ctcm_channel_types type,
 					goto nomem_return;
 
 	ch->cdev = cdev;
-	snprintf(ch->id, CTCM_ID_SIZE, "ch-%s", dev_name(&cdev->dev));
+	scnprintf(ch->id, CTCM_ID_SIZE, "ch-%s", dev_name(&cdev->dev));
 	ch->type = type;
 
 	/*
@@ -1505,8 +1505,8 @@ static int ctcm_new_device(struct ccwgroup_device *cgdev)
 
 	type = get_channel_type(&cdev0->id);
 
-	snprintf(read_id, CTCM_ID_SIZE, "ch-%s", dev_name(&cdev0->dev));
-	snprintf(write_id, CTCM_ID_SIZE, "ch-%s", dev_name(&cdev1->dev));
+	scnprintf(read_id, CTCM_ID_SIZE, "ch-%s", dev_name(&cdev0->dev));
+	scnprintf(write_id, CTCM_ID_SIZE, "ch-%s", dev_name(&cdev1->dev));
 
 	ret = add_channel(cdev0, type, priv);
 	if (ret) {
diff --git a/drivers/s390/net/ctcm_main.h b/drivers/s390/net/ctcm_main.h
index 90bd7b3f80c3..25164e8bf13d 100644
--- a/drivers/s390/net/ctcm_main.h
+++ b/drivers/s390/net/ctcm_main.h
@@ -100,6 +100,7 @@ enum ctcm_channel_types {
 #define CTCM_PROTO_MPC		4
 #define CTCM_PROTO_MAX		4
 
+#define CTCM_STATSIZE_LIMIT	64
 #define CTCM_BUFSIZE_LIMIT	65535
 #define CTCM_BUFSIZE_DEFAULT	32768
 #define MPC_BUFSIZE_DEFAULT	CTCM_BUFSIZE_LIMIT
diff --git a/drivers/s390/net/ctcm_mpc.c b/drivers/s390/net/ctcm_mpc.c
index 8ac213a55141..64996c86defc 100644
--- a/drivers/s390/net/ctcm_mpc.c
+++ b/drivers/s390/net/ctcm_mpc.c
@@ -144,9 +144,9 @@ void ctcmpc_dumpit(char *buf, int len)
 
 	for (ct = 0; ct < len; ct++, ptr++, rptr++) {
 		if (sw == 0) {
-			sprintf(addr, "%16.16llx", (__u64)rptr);
+			scnprintf(addr, sizeof(addr), "%16.16llx", (__u64)rptr);
 
-			sprintf(boff, "%4.4X", (__u32)ct);
+			scnprintf(boff, sizeof(boff), "%4.4X", (__u32)ct);
 			bhex[0] = '\0';
 			basc[0] = '\0';
 		}
@@ -155,7 +155,7 @@ void ctcmpc_dumpit(char *buf, int len)
 		if (sw == 8)
 			strcat(bhex, "	");
 
-		sprintf(tbuf, "%2.2llX", (__u64)*ptr);
+		scnprintf(tbuf, sizeof(tbuf), "%2.2llX", (__u64)*ptr);
 
 		tbuf[2] = '\0';
 		strcat(bhex, tbuf);
@@ -171,8 +171,8 @@ void ctcmpc_dumpit(char *buf, int len)
 			continue;
 		if ((strcmp(duphex, bhex)) != 0) {
 			if (dup != 0) {
-				sprintf(tdup,
-					"Duplicate as above to %s", addr);
+				scnprintf(tdup, sizeof(tdup),
+					  "Duplicate as above to %s", addr);
 				ctcm_pr_debug("		       --- %s ---\n",
 						tdup);
 			}
@@ -197,14 +197,16 @@ void ctcmpc_dumpit(char *buf, int len)
 			strcat(basc, " ");
 		}
 		if (dup != 0) {
-			sprintf(tdup, "Duplicate as above to %s", addr);
+			scnprintf(tdup, sizeof(tdup),
+				  "Duplicate as above to %s", addr);
 			ctcm_pr_debug("		       --- %s ---\n", tdup);
 		}
 		ctcm_pr_debug("   %s (+%s) : %s  [%s]\n",
 					addr, boff, bhex, basc);
 	} else {
 		if (dup >= 1) {
-			sprintf(tdup, "Duplicate as above to %s", addr);
+			scnprintf(tdup, sizeof(tdup),
+				  "Duplicate as above to %s", addr);
 			ctcm_pr_debug("		       --- %s ---\n", tdup);
 		}
 		if (dup != 0) {
@@ -291,7 +293,7 @@ static struct net_device *ctcmpc_get_dev(int port_num)
 	struct net_device *dev;
 	struct ctcm_priv *priv;
 
-	sprintf(device, "%s%i", MPC_DEVICE_NAME, port_num);
+	scnprintf(device, sizeof(device), "%s%i", MPC_DEVICE_NAME, port_num);
 
 	dev = __dev_get_by_name(&init_net, device);
 
diff --git a/drivers/s390/net/ctcm_sysfs.c b/drivers/s390/net/ctcm_sysfs.c
index 98680c2cc4e4..0c5d8a3eaa2e 100644
--- a/drivers/s390/net/ctcm_sysfs.c
+++ b/drivers/s390/net/ctcm_sysfs.c
@@ -86,24 +86,24 @@ static void ctcm_print_statistics(struct ctcm_priv *priv)
 		return;
 	p = sbuf;
 
-	p += sprintf(p, "  Device FSM state: %s\n",
-		     fsm_getstate_str(priv->fsm));
-	p += sprintf(p, "  RX channel FSM state: %s\n",
-		     fsm_getstate_str(priv->channel[CTCM_READ]->fsm));
-	p += sprintf(p, "  TX channel FSM state: %s\n",
-		     fsm_getstate_str(priv->channel[CTCM_WRITE]->fsm));
-	p += sprintf(p, "  Max. TX buffer used: %ld\n",
-		     priv->channel[WRITE]->prof.maxmulti);
-	p += sprintf(p, "  Max. chained SKBs: %ld\n",
-		     priv->channel[WRITE]->prof.maxcqueue);
-	p += sprintf(p, "  TX single write ops: %ld\n",
-		     priv->channel[WRITE]->prof.doios_single);
-	p += sprintf(p, "  TX multi write ops: %ld\n",
-		     priv->channel[WRITE]->prof.doios_multi);
-	p += sprintf(p, "  Netto bytes written: %ld\n",
-		     priv->channel[WRITE]->prof.txlen);
-	p += sprintf(p, "  Max. TX IO-time: %u\n",
-		     jiffies_to_usecs(priv->channel[WRITE]->prof.tx_time));
+	p += scnprintf(p, CTCM_STATSIZE_LIMIT, "  Device FSM state: %s\n",
+		       fsm_getstate_str(priv->fsm));
+	p += scnprintf(p, CTCM_STATSIZE_LIMIT, "  RX channel FSM state: %s\n",
+		       fsm_getstate_str(priv->channel[CTCM_READ]->fsm));
+	p += scnprintf(p, CTCM_STATSIZE_LIMIT, "  TX channel FSM state: %s\n",
+		       fsm_getstate_str(priv->channel[CTCM_WRITE]->fsm));
+	p += scnprintf(p, CTCM_STATSIZE_LIMIT, "  Max. TX buffer used: %ld\n",
+		       priv->channel[WRITE]->prof.maxmulti);
+	p += scnprintf(p, CTCM_STATSIZE_LIMIT, "  Max. chained SKBs: %ld\n",
+		       priv->channel[WRITE]->prof.maxcqueue);
+	p += scnprintf(p, CTCM_STATSIZE_LIMIT, "  TX single write ops: %ld\n",
+		       priv->channel[WRITE]->prof.doios_single);
+	p += scnprintf(p, CTCM_STATSIZE_LIMIT, "  TX multi write ops: %ld\n",
+		       priv->channel[WRITE]->prof.doios_multi);
+	p += scnprintf(p, CTCM_STATSIZE_LIMIT, "  Netto bytes written: %ld\n",
+		       priv->channel[WRITE]->prof.txlen);
+	p += scnprintf(p, CTCM_STATSIZE_LIMIT, "  Max. TX IO-time: %u\n",
+		       jiffies_to_usecs(priv->channel[WRITE]->prof.tx_time));
 
 	printk(KERN_INFO "Statistics for %s:\n%s",
 				priv->channel[CTCM_WRITE]->netdev->name, sbuf);
-- 
2.39.2

Re: [PATCH net-next 2/4] s390/lcs: Convert sprintf to scnprintf

[Simon Horman]

On Tue, Jun 20, 2023 at 10:34:09AM +0200, Alexandra Winter wrote:
> From: Thorsten Winkler <twinkler@linux.ibm.com>
> 
> This LWN article explains the rationale for this change
> https: //lwn.net/Articles/69419/
> Ie. snprintf() returns what *would* be the resulting length,
> while scnprintf() returns the actual length.

Hi Alexandra,

Although I agree that it's nice to use scnprintf() the justification given
seems a bit odd: it talks of the return value but it is ignored both before
and after this patch.

Likewise for some of the changes in patch 4/4.

Also is it intentional that there is a space in the URL immediately
after 'http:' ? Maybe mangled by something. Not that it really maters
AFAIC.

> Reported-by: Jules Irenge <jbi.octave@gmail.com>
> Reviewed-by: Alexandra Winter <wintera@linux.ibm.com>
> Signed-off-by: Thorsten Winkler <twinkler@linux.ibm.com>
> Signed-off-by: Alexandra Winter <wintera@linux.ibm.com>
> ---
>  drivers/s390/net/lcs.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/s390/net/lcs.h b/drivers/s390/net/lcs.h
> index bd52caa3b11b..a2699b70b050 100644
> --- a/drivers/s390/net/lcs.h
> +++ b/drivers/s390/net/lcs.h
> @@ -21,7 +21,7 @@ do { \
>  #define LCS_DBF_TEXT_(level,name,text...) \
>  	do { \
>  		if (debug_level_enabled(lcs_dbf_##name, level)) { \
> -			sprintf(debug_buffer, text); \
> +			scnprintf(debug_buffer, sizeof(debug_buffer), text); \
>  			debug_text_event(lcs_dbf_##name, level, debug_buffer); \
>  		} \
>  	} while (0)
> -- 
> 2.39.2
> 
> 

Re: [PATCH net-next 3/4] s390/ctcm: Convert sysfs sprintf to sysfs_emit

[Simon Horman]

On Tue, Jun 20, 2023 at 10:34:10AM +0200, Alexandra Winter wrote:
> From: Thorsten Winkler <twinkler@linux.ibm.com>
> 
> Following the advice of the Documentation/filesystems/sysfs.rst.
> All sysfs related show()-functions should only use sysfs_emit() or
> sysfs_emit_at() when formatting the value to be returned to user space.
> 
> Reviewed-by: Alexandra Winter <wintera@linux.ibm.com>
> Signed-off-by: Thorsten Winkler <twinkler@linux.ibm.com>
> Signed-off-by: Alexandra Winter <wintera@linux.ibm.com>

Reviewed-by: Simon Horman <simon.horman@corigine.com>

Re: [PATCH net-next 1/4] s390/lcs: Convert sysfs sprintf to sysfs_emit

[Simon Horman]

On Tue, Jun 20, 2023 at 10:34:08AM +0200, Alexandra Winter wrote:
> From: Thorsten Winkler <twinkler@linux.ibm.com>
> 
> Following the advice of the Documentation/filesystems/sysfs.rst.
> All sysfs related show()-functions should only use sysfs_emit() or
> sysfs_emit_at() when formatting the value to be returned to user space.
> 
> While at it, follow Linux kernel coding style and unify indentation
> 
> Reported-by: Jules Irenge <jbi.octave@gmail.com>
> Reported-by: Joe Perches <joe@perches.com>
> Reviewed-by: Alexandra Winter <wintera@linux.ibm.com>
> Signed-off-by: Thorsten Winkler <twinkler@linux.ibm.com>
> Signed-off-by: Alexandra Winter <wintera@linux.ibm.com>

Reviewed-by: Simon Horman <simon.horman@corigine.com>

Re: [PATCH net-next 2/4] s390/lcs: Convert sprintf to scnprintf

[Alexandra Winter]

On 20.06.23 21:16, Simon Horman wrote:
> On Tue, Jun 20, 2023 at 10:34:09AM +0200, Alexandra Winter wrote:
>> From: Thorsten Winkler <twinkler@linux.ibm.com>
>>
>> This LWN article explains the rationale for this change
>> https: //lwn.net/Articles/69419/
>> Ie. snprintf() returns what *would* be the resulting length,
>> while scnprintf() returns the actual length.
> Hi Alexandra,
> 
> Although I agree that it's nice to use scnprintf() the justification given
> seems a bit odd: it talks of the return value but it is ignored both before
> and after this patch.
> 
> Likewise for some of the changes in patch 4/4.


You are correct. The main improvement of these patches is to get rid of sprintf.
And we decided to use scnprintf everywhere. I'll send a v2 with a slightly
updated description.


> 
> Also is it intentional that there is a space in the URL immediately
> after 'http:' ? Maybe mangled by something. Not that it really maters
> AFAIC.


Thanks for spotting this, Simon. Corrected in v2.