Commit 1471d85f authored by Thorsten Winkler's avatar Thorsten Winkler Committed by Paolo Abeni
Browse files

s390/ctcm: Convert sprintf/snprintf to scnprintf 

This LWN article explains the why scnprintf is preferred over snprintf
in general
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: default avatarAlexandra Winter <wintera@linux.ibm.com>
Signed-off-by: default avatarThorsten Winkler <twinkler@linux.ibm.com>
Signed-off-by: default avatarAlexandra Winter <wintera@linux.ibm.com>
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parent d585e4b7

drivers/s390/net/ctcm_dbug.c

+1 −1
Original line number Diff line number Diff line
@@ -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);

drivers/s390/net/ctcm_main.c

+3 −3
Original line number Diff line number Diff line
@@ -1333,7 +1333,7 @@ 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;



	/*
@@ -1498,8 +1498,8 @@ 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) {

drivers/s390/net/ctcm_main.h

+1 −0
Original line number Diff line number Diff line
@@ -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

drivers/s390/net/ctcm_mpc.c

+10 −8
Original line number Diff line number Diff line
@@ -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);
@@ -171,7 +171,7 @@ void ctcmpc_dumpit(char *buf, int len) 
			continue;

		if ((strcmp(duphex, bhex)) != 0) {

			if (dup != 0) {

				sprintf(tdup,

				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);

drivers/s390/net/ctcm_sysfs.c

+18 −18
Original line number Diff line number Diff line
@@ -86,23 +86,23 @@ static void ctcm_print_statistics(struct ctcm_priv *priv) 
		return;

	p = sbuf;



	p += sprintf(p, "  Device FSM state: %s\n",

	p += scnprintf(p, CTCM_STATSIZE_LIMIT, "  Device FSM state: %s\n",

		       fsm_getstate_str(priv->fsm));

	p += sprintf(p, "  RX channel FSM state: %s\n",

	p += scnprintf(p, CTCM_STATSIZE_LIMIT, "  RX channel FSM state: %s\n",

		       fsm_getstate_str(priv->channel[CTCM_READ]->fsm));

	p += sprintf(p, "  TX channel FSM state: %s\n",

	p += scnprintf(p, CTCM_STATSIZE_LIMIT, "  TX channel FSM state: %s\n",

		       fsm_getstate_str(priv->channel[CTCM_WRITE]->fsm));

	p += sprintf(p, "  Max. TX buffer used: %ld\n",

	p += scnprintf(p, CTCM_STATSIZE_LIMIT, "  Max. TX buffer used: %ld\n",

		       priv->channel[WRITE]->prof.maxmulti);

	p += sprintf(p, "  Max. chained SKBs: %ld\n",

	p += scnprintf(p, CTCM_STATSIZE_LIMIT, "  Max. chained SKBs: %ld\n",

		       priv->channel[WRITE]->prof.maxcqueue);

	p += sprintf(p, "  TX single write ops: %ld\n",

	p += scnprintf(p, CTCM_STATSIZE_LIMIT, "  TX single write ops: %ld\n",

		       priv->channel[WRITE]->prof.doios_single);

	p += sprintf(p, "  TX multi write ops: %ld\n",

	p += scnprintf(p, CTCM_STATSIZE_LIMIT, "  TX multi write ops: %ld\n",

		       priv->channel[WRITE]->prof.doios_multi);

	p += sprintf(p, "  Netto bytes written: %ld\n",

	p += scnprintf(p, CTCM_STATSIZE_LIMIT, "  Netto bytes written: %ld\n",

		       priv->channel[WRITE]->prof.txlen);

	p += sprintf(p, "  Max. TX IO-time: %u\n",

	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",