[PATCH -next 0/2] seq: Convert seq_puts and seq_putc to return void

[PATCH -next 0/2] seq: Convert seq_puts and seq_putc to return void

[Joe Perches]

These are error prone, so return void adn use seq_has_overflowed instead

Joe Perches (2):
  seq_puts: Convert to return void and convert uses too.
  seq_putc: Convert to return void and convert uses too.

 drivers/char/ipmi/ipmi_msghandler.c                |  4 +-
 drivers/parisc/ccio-dma.c                          |  7 +-
 drivers/regulator/dbx500-prcmu.c                   | 21 ++----
 drivers/usb/gadget/udc/goku_udc.c                  | 81 +++++++++++-----------
 drivers/watchdog/bcm_kona_wdt.c                    | 43 +++++++-----
 fs/seq_file.c                                      | 26 +++----
 include/linux/seq_file.h                           |  4 +-
 ipc/util.c                                         |  6 +-
 .../netfilter/nf_conntrack_l3proto_ipv4_compat.c   |  4 +-
 net/netfilter/nf_conntrack_expect.c                |  4 +-
 10 files changed, 105 insertions(+), 95 deletions(-)

-- 
2.1.2

[PATCH -next 1/2] seq_puts: Convert to return void and convert uses too.

[Joe Perches]

Using the return value of seq_puts is error-prone, so
make it return void instead.

Use seq_has_overflowed where appropriate instead of the
old return value.

Signed-off-by: Joe Perches <joe@perches.com>
---
 drivers/parisc/ccio-dma.c         |  7 ++--
 drivers/regulator/dbx500-prcmu.c  | 21 ++++------
 drivers/usb/gadget/udc/goku_udc.c | 81 ++++++++++++++++++++-------------------
 drivers/watchdog/bcm_kona_wdt.c   | 43 ++++++++++++---------
 fs/seq_file.c                     | 15 ++++----
 include/linux/seq_file.h          |  2 +-
 ipc/util.c                        |  6 ++-
 7 files changed, 89 insertions(+), 86 deletions(-)

diff --git a/drivers/parisc/ccio-dma.c b/drivers/parisc/ccio-dma.c
index 8b490d7..c40cc98 100644
--- a/drivers/parisc/ccio-dma.c
+++ b/drivers/parisc/ccio-dma.c
@@ -1101,7 +1101,6 @@ static const struct file_operations ccio_proc_info_fops = {
 
 static int ccio_proc_bitmap_info(struct seq_file *m, void *p)
 {
-	int len = 0;
 	struct ioc *ioc = ioc_list;
 
 	while (ioc != NULL) {
@@ -1110,11 +1109,11 @@ static int ccio_proc_bitmap_info(struct seq_file *m, void *p)
 
 		for (j = 0; j < (ioc->res_size / sizeof(u32)); j++) {
 			if ((j & 7) == 0)
-				len += seq_puts(m, "\n   ");
-			len += seq_printf(m, "%08x", *res_ptr);
+				seq_puts(m, "\n   ");
+			seq_printf(m, "%08x", *res_ptr);
 			res_ptr++;
 		}
-		len += seq_puts(m, "\n\n");
+		seq_puts(m, "\n\n");
 		ioc = ioc->next;
 		break; /* XXX - remove me */
 	}
diff --git a/drivers/regulator/dbx500-prcmu.c b/drivers/regulator/dbx500-prcmu.c
index 2d16b9f..b778ca9 100644
--- a/drivers/regulator/dbx500-prcmu.c
+++ b/drivers/regulator/dbx500-prcmu.c
@@ -129,14 +129,8 @@ static int ux500_regulator_status_print(struct seq_file *s, void *p)
 	int i;
 
 	/* print dump header */
-	err = seq_puts(s, "ux500-regulator status:\n");
-	if (err < 0)
-		dev_err(dev, "seq_puts overflow\n");
-
-	err = seq_printf(s, "%31s : %8s : %8s\n", "current",
-		"before", "after");
-	if (err < 0)
-		dev_err(dev, "seq_printf overflow\n");
+	seq_puts(s, "ux500-regulator status:\n");
+	seq_printf(s, "%31s : %8s : %8s\n", "current", "before", "after");
 
 	for (i = 0; i < rdebug.num_regulators; i++) {
 		struct dbx500_regulator_info *info;
@@ -144,12 +138,11 @@ static int ux500_regulator_status_print(struct seq_file *s, void *p)
 		info = &rdebug.regulator_array[i];
 
 		/* print status */
-		err = seq_printf(s, "%20s : %8s : %8s : %8s\n", info->desc.name,
-			info->is_enabled ? "enabled" : "disabled",
-			rdebug.state_before_suspend[i] ? "enabled" : "disabled",
-			rdebug.state_after_suspend[i] ? "enabled" : "disabled");
-		if (err < 0)
-			dev_err(dev, "seq_printf overflow\n");
+		seq_printf(s, "%20s : %8s : %8s : %8s\n",
+			   info->desc.name,
+			   info->is_enabled ? "enabled" : "disabled",
+			   rdebug.state_before_suspend[i] ? "enabled" : "disabled",
+			   rdebug.state_after_suspend[i] ? "enabled" : "disabled");
 	}
 
 	return 0;
diff --git a/drivers/usb/gadget/udc/goku_udc.c b/drivers/usb/gadget/udc/goku_udc.c
index 5b9176e..c16b4d9 100644
--- a/drivers/usb/gadget/udc/goku_udc.c
+++ b/drivers/usb/gadget/udc/goku_udc.c
@@ -1135,44 +1135,47 @@ static int udc_proc_read(struct seq_file *m, void *v)
 			continue;
 
 		tmp = readl(ep->reg_status);
-		if (seq_printf(m,
-			"%s %s max %u %s, irqs %lu, "
-			"status %02x (%s) " FOURBITS "\n",
-			ep->ep.name,
-			ep->is_in ? "in" : "out",
-			ep->ep.maxpacket,
-			ep->dma ? "dma" : "pio",
-			ep->irqs,
-			tmp, ({ char *s;
-			switch (tmp & EPxSTATUS_EP_MASK) {
-			case EPxSTATUS_EP_READY:
-				s = "ready"; break;
-			case EPxSTATUS_EP_DATAIN:
-				s = "packet"; break;
-			case EPxSTATUS_EP_FULL:
-				s = "full"; break;
-			case EPxSTATUS_EP_TX_ERR:	// host will retry
-				s = "tx_err"; break;
-			case EPxSTATUS_EP_RX_ERR:
-				s = "rx_err"; break;
-			case EPxSTATUS_EP_BUSY:		/* ep0 only */
-				s = "busy"; break;
-			case EPxSTATUS_EP_STALL:
-				s = "stall"; break;
-			case EPxSTATUS_EP_INVALID:	// these "can't happen"
-				s = "invalid"; break;
-			default:
-				s = "?"; break;
-			} s; }),
-			(tmp & EPxSTATUS_TOGGLE) ? "data1" : "data0",
-			(tmp & EPxSTATUS_SUSPEND) ? " suspend" : "",
-			(tmp & EPxSTATUS_FIFO_DISABLE) ? " disable" : "",
-			(tmp & EPxSTATUS_STAGE_ERROR) ? " ep0stat" : ""
-			) < 0)
+		seq_printf(m, "%s %s max %u %s, irqs %lu, status %02x (%s) " FOURBITS "\n",
+			   ep->ep.name,
+			   ep->is_in ? "in" : "out",
+			   ep->ep.maxpacket,
+			   ep->dma ? "dma" : "pio",
+			   ep->irqs,
+			   tmp,
+			   ({
+				char *s;
+				switch (tmp & EPxSTATUS_EP_MASK) {
+				case EPxSTATUS_EP_READY:
+					s = "ready"; break;
+				case EPxSTATUS_EP_DATAIN:
+					s = "packet"; break;
+				case EPxSTATUS_EP_FULL:
+					s = "full"; break;
+				case EPxSTATUS_EP_TX_ERR:  /* host will retry */
+					s = "tx_err"; break;
+				case EPxSTATUS_EP_RX_ERR:
+					s = "rx_err"; break;
+				case EPxSTATUS_EP_BUSY:    /* ep0 only */
+					s = "busy"; break;
+				case EPxSTATUS_EP_STALL:
+					s = "stall"; break;
+				case EPxSTATUS_EP_INVALID: /* "can't happen" */
+					s = "invalid"; break;
+				default:
+					s = "?"; break;
+				}
+				s;
+			   }),
+			   (tmp & EPxSTATUS_TOGGLE) ? "data1" : "data0",
+			   (tmp & EPxSTATUS_SUSPEND) ? " suspend" : "",
+			   (tmp & EPxSTATUS_FIFO_DISABLE) ? " disable" : "",
+			   (tmp & EPxSTATUS_STAGE_ERROR) ? " ep0stat" : "");
+		if (seq_has_overflowed(m) < 0)
 			goto done;
 
 		if (list_empty(&ep->queue)) {
-			if (seq_puts(m, "\t(nothing queued)\n") < 0)
+			seq_puts(m, "\t(nothing queued)\n");
+			if (seq_has_overflowed(m))
 				goto done;
 			continue;
 		}
@@ -1187,10 +1190,10 @@ static int udc_proc_read(struct seq_file *m, void *v)
 			} else
 				tmp = req->req.actual;
 
-			if (seq_printf(m,
-				"\treq %p len %u/%u buf %p\n",
-				&req->req, tmp, req->req.length,
-				req->req.buf) < 0)
+			seq_printf(m, "\treq %p len %u/%u buf %p\n",
+				   &req->req, tmp, req->req.length,
+				   req->req.buf);
+			if (seq_has_overflowed(m))
 				goto done;
 		}
 	}
diff --git a/drivers/watchdog/bcm_kona_wdt.c b/drivers/watchdog/bcm_kona_wdt.c
index 4e37db3..0e5ec3c 100644
--- a/drivers/watchdog/bcm_kona_wdt.c
+++ b/drivers/watchdog/bcm_kona_wdt.c
@@ -102,34 +102,39 @@ static int bcm_kona_wdt_dbg_show(struct seq_file *s, void *data)
 	int ctl_val, cur_val, ret;
 	unsigned long flags;
 	struct bcm_kona_wdt *wdt = s->private;
+	int ctl, cur, ctl_sec, cur_sec, res;
 
-	if (!wdt)
-		return seq_puts(s, "No device pointer\n");
-
+	if (!wdt) {
+		seq_puts(s, "No device pointer\n");
+		return 0;
+	}
 	spin_lock_irqsave(&wdt->lock, flags);
 	ctl_val = secure_register_read(wdt, SECWDOG_CTRL_REG);
 	cur_val = secure_register_read(wdt, SECWDOG_COUNT_REG);
 	spin_unlock_irqrestore(&wdt->lock, flags);
 
 	if (ctl_val < 0 || cur_val < 0) {
-		ret = seq_puts(s, "Error accessing hardware\n");
-	} else {
-		int ctl, cur, ctl_sec, cur_sec, res;
-
-		ctl = ctl_val & SECWDOG_COUNT_MASK;
-		res = (ctl_val & SECWDOG_RES_MASK) >> SECWDOG_CLKS_SHIFT;
-		cur = cur_val & SECWDOG_COUNT_MASK;
-		ctl_sec = TICKS_TO_SECS(ctl, wdt);
-		cur_sec = TICKS_TO_SECS(cur, wdt);
-		ret = seq_printf(s, "Resolution: %d / %d\n"
-				"Control: %d s / %d (%#x) ticks\n"
-				"Current: %d s / %d (%#x) ticks\n"
-				"Busy count: %lu\n", res,
-				wdt->resolution, ctl_sec, ctl, ctl, cur_sec,
-				cur, cur, wdt->busy_count);
+		seq_puts(s, "Error accessing hardware\n");
+		return 0;
 	}
 
-	return ret;
+	ctl = ctl_val & SECWDOG_COUNT_MASK;
+	res = (ctl_val & SECWDOG_RES_MASK) >> SECWDOG_CLKS_SHIFT;
+	cur = cur_val & SECWDOG_COUNT_MASK;
+	ctl_sec = TICKS_TO_SECS(ctl, wdt);
+	cur_sec = TICKS_TO_SECS(cur, wdt);
+	seq_printf(s,
+		   "Resolution: %d / %d\n"
+		   "Control: %d s / %d (%#x) ticks\n"
+		   "Current: %d s / %d (%#x) ticks\n"
+		   "Busy count: %lu\n",
+		   res, wdt->resolution,
+		   ctl_sec, ctl, ctl,
+		   cur_sec, cur, cur,
+		   wdt->busy_count);
+	}
+
+	return 0;
 }
 
 static int bcm_kona_dbg_open(struct inode *inode, struct file *file)
diff --git a/fs/seq_file.c b/fs/seq_file.c
index 353948b..e6be05a 100644
--- a/fs/seq_file.c
+++ b/fs/seq_file.c
@@ -683,16 +683,17 @@ int seq_putc(struct seq_file *m, char c)
 }
 EXPORT_SYMBOL(seq_putc);
 
-int seq_puts(struct seq_file *m, const char *s)
+void seq_puts(struct seq_file *m, const char *s)
 {
 	int len = strlen(s);
-	if (m->count + len < m->size) {
-		memcpy(m->buf + m->count, s, len);
-		m->count += len;
-		return 0;
+
+	if (m->count + len >= m->size) {
+		seq_set_overflow(m);
+		return;
 	}
-	seq_set_overflow(m);
-	return -1;
+
+	memcpy(m->buf + m->count, s, len);
+	m->count += len;
 }
 EXPORT_SYMBOL(seq_puts);
 
diff --git a/include/linux/seq_file.h b/include/linux/seq_file.h
index cf6a9da..9b02cb6 100644
--- a/include/linux/seq_file.h
+++ b/include/linux/seq_file.h
@@ -116,7 +116,7 @@ loff_t seq_lseek(struct file *, loff_t, int);
 int seq_release(struct inode *, struct file *);
 int seq_escape(struct seq_file *, const char *, const char *);
 int seq_putc(struct seq_file *m, char c);
-int seq_puts(struct seq_file *m, const char *s);
+void seq_puts(struct seq_file *m, const char *s);
 int seq_write(struct seq_file *seq, const void *data, size_t len);
 
 __printf(2, 3) int seq_printf(struct seq_file *, const char *, ...);
diff --git a/ipc/util.c b/ipc/util.c
index 106bed0..4f726b7 100644
--- a/ipc/util.c
+++ b/ipc/util.c
@@ -837,8 +837,10 @@ static int sysvipc_proc_show(struct seq_file *s, void *it)
 	struct ipc_proc_iter *iter = s->private;
 	struct ipc_proc_iface *iface = iter->iface;
 
-	if (it == SEQ_START_TOKEN)
-		return seq_puts(s, iface->header);
+	if (it == SEQ_START_TOKEN) {
+		seq_puts(s, iface->header);
+		return seq_has_overflowed(s);
+	}
 
 	return iface->show(s, it);
 }
-- 
2.1.2

[PATCH -next 2/2] seq_putc: Convert to return void and convert uses too.

[Joe Perches]

Using the return value of seq_putc is error-prone, so
make it return void instead.

Reverse the logic in seq_putc to make it like seq_puts.

Signed-off-by: Joe Perches <joe@perches.com>
---
 drivers/char/ipmi/ipmi_msghandler.c                   |  4 +++-
 fs/seq_file.c                                         | 11 ++++++-----
 include/linux/seq_file.h                              |  2 +-
 net/ipv4/netfilter/nf_conntrack_l3proto_ipv4_compat.c |  4 +++-
 net/netfilter/nf_conntrack_expect.c                   |  4 +++-
 5 files changed, 16 insertions(+), 9 deletions(-)

diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c
index f816211..c12fb30 100644
--- a/drivers/char/ipmi/ipmi_msghandler.c
+++ b/drivers/char/ipmi/ipmi_msghandler.c
@@ -1953,7 +1953,9 @@ static int smi_ipmb_proc_show(struct seq_file *m, void *v)
 	seq_printf(m, "%x", intf->channels[0].address);
 	for (i = 1; i < IPMI_MAX_CHANNELS; i++)
 		seq_printf(m, " %x", intf->channels[i].address);
-	return seq_putc(m, '\n');
+	seq_putc(m, '\n');
+
+	return 0;
 }
 
 static int smi_ipmb_proc_open(struct inode *inode, struct file *file)
diff --git a/fs/seq_file.c b/fs/seq_file.c
index e6be05a..5ca5af9 100644
--- a/fs/seq_file.c
+++ b/fs/seq_file.c
@@ -673,13 +673,14 @@ int seq_open_private(struct file *filp, const struct seq_operations *ops,
 }
 EXPORT_SYMBOL(seq_open_private);
 
-int seq_putc(struct seq_file *m, char c)
+void seq_putc(struct seq_file *m, char c)
 {
-	if (m->count < m->size) {
-		m->buf[m->count++] = c;
-		return 0;
+	if (m->count >= m->size) {
+		seq_set_overflow(m);
+		return;
 	}
-	return -1;
+
+	m->buf[m->count++] = c;
 }
 EXPORT_SYMBOL(seq_putc);
 
diff --git a/include/linux/seq_file.h b/include/linux/seq_file.h
index 9b02cb6..c1e47ff 100644
--- a/include/linux/seq_file.h
+++ b/include/linux/seq_file.h
@@ -115,7 +115,7 @@ ssize_t seq_read(struct file *, char __user *, size_t, loff_t *);
 loff_t seq_lseek(struct file *, loff_t, int);
 int seq_release(struct inode *, struct file *);
 int seq_escape(struct seq_file *, const char *, const char *);
-int seq_putc(struct seq_file *m, char c);
+void seq_putc(struct seq_file *m, char c);
 void seq_puts(struct seq_file *m, const char *s);
 int seq_write(struct seq_file *seq, const void *data, size_t len);
 
diff --git a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4_compat.c b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4_compat.c
index a460a87..f0dfe92 100644
--- a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4_compat.c
+++ b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4_compat.c
@@ -300,7 +300,9 @@ static int exp_seq_show(struct seq_file *s, void *v)
 		    __nf_ct_l3proto_find(exp->tuple.src.l3num),
 		    __nf_ct_l4proto_find(exp->tuple.src.l3num,
 					 exp->tuple.dst.protonum));
-	return seq_putc(s, '\n');
+	seq_putc(s, '\n');
+
+	return 0;
 }
 
 static const struct seq_operations exp_seq_ops = {
diff --git a/net/netfilter/nf_conntrack_expect.c b/net/netfilter/nf_conntrack_expect.c
index 91a1837..7a17070 100644
--- a/net/netfilter/nf_conntrack_expect.c
+++ b/net/netfilter/nf_conntrack_expect.c
@@ -561,7 +561,9 @@ static int exp_seq_show(struct seq_file *s, void *v)
 				   helper->expect_policy[expect->class].name);
 	}
 
-	return seq_putc(s, '\n');
+	seq_putc(s, '\n');
+
+	return 0;
 }
 
 static const struct seq_operations exp_seq_ops = {
-- 
2.1.2

Re: [PATCH -next 1/2] seq_puts: Convert to return void and convert uses too.

[Mark Brown]

[-- Attachment #1: Type: text/plain, Size: 191 bytes --]

On Mon, Nov 10, 2014 at 10:58:56AM -0800, Joe Perches wrote:
> Using the return value of seq_puts is error-prone, so
> make it return void instead.

Acked-by: Mark Brown <broonie@kernel.org>

[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 473 bytes --]

Re: [PATCH -next 1/2] seq_puts: Convert to return void and convert uses too.

[Petr Mladek]

On Mon 2014-11-10 10:58:56, Joe Perches wrote:
> diff --git a/ipc/util.c b/ipc/util.c
> index 106bed0..4f726b7 100644
> --- a/ipc/util.c
> +++ b/ipc/util.c
> @@ -837,8 +837,10 @@ static int sysvipc_proc_show(struct seq_file *s, void *it)
>  	struct ipc_proc_iter *iter = s->private;
>  	struct ipc_proc_iface *iface = iter->iface;
>  
> -	if (it == SEQ_START_TOKEN)
> -		return seq_puts(s, iface->header);
> +	if (it == SEQ_START_TOKEN) {
> +		seq_puts(s, iface->header);
> +		return seq_has_overflowed(s);

It should return 0. The overflow is detected by traverse() that is
called from seq_read(). If the overflow happens, the size of the
buffer is increased and show() is called again.

> +	}
>  
>  	return iface->show(s, it);

This should stay as is. It seems that the show() function might also
return negative value in case of some other failure. See the error
handling of "error = m->op->show(m, p);" in traverse() in fs/seq_file.c


The rest of the patch looks fine.

Best Regards,
Petr

Re: [PATCH -next 2/2] seq_putc: Convert to return void and convert uses too.

[Petr Mladek]

On Mon 2014-11-10 10:58:57, Joe Perches wrote:
> Using the return value of seq_putc is error-prone, so
> make it return void instead.
> 
> Reverse the logic in seq_putc to make it like seq_puts.
> 
> Signed-off-by: Joe Perches <joe@perches.com>

Reviewed-by: Petr Mladek <pmladek@suse.cz>

The changes are correct. The show() functions should return 0
even when there is an overflow. They are called by traverse()
from seq_read() that might increase the buffer size and try again.


Best Regards,
Petr

Re: [PATCH -next 2/2] seq_putc: Convert to return void and convert uses too.

[Pablo Neira Ayuso]

On Tue, Nov 11, 2014 at 02:47:40PM +0100, Petr Mladek wrote:
> On Mon 2014-11-10 10:58:57, Joe Perches wrote:
> > Using the return value of seq_putc is error-prone, so
> > make it return void instead.
> > 
> > Reverse the logic in seq_putc to make it like seq_puts.
> > 
> > Signed-off-by: Joe Perches <joe@perches.com>
> 
> Reviewed-by: Petr Mladek <pmladek@suse.cz>
> 
> The changes are correct. The show() functions should return 0
> even when there is an overflow. They are called by traverse()
> from seq_read() that might increase the buffer size and try again.

Just in case you need this for the netfilter chunks:

Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>

Thanks.

Re: [PATCH -next 2/2] seq_putc: Convert to return void and convert uses too.

[Corey Minyard]

Ok by me for the IPMI part.

Reviewed-by: Corey Minyard <cminyard@mvista.com>

On 11/10/2014 12:58 PM, Joe Perches wrote:
> Using the return value of seq_putc is error-prone, so
> make it return void instead.
>
> Reverse the logic in seq_putc to make it like seq_puts.
>
> Signed-off-by: Joe Perches <joe@perches.com>
> ---
>  drivers/char/ipmi/ipmi_msghandler.c                   |  4 +++-
>  fs/seq_file.c                                         | 11 ++++++-----
>  include/linux/seq_file.h                              |  2 +-
>  net/ipv4/netfilter/nf_conntrack_l3proto_ipv4_compat.c |  4 +++-
>  net/netfilter/nf_conntrack_expect.c                   |  4 +++-
>  5 files changed, 16 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c
> index f816211..c12fb30 100644
> --- a/drivers/char/ipmi/ipmi_msghandler.c
> +++ b/drivers/char/ipmi/ipmi_msghandler.c
> @@ -1953,7 +1953,9 @@ static int smi_ipmb_proc_show(struct seq_file *m, void *v)
>  	seq_printf(m, "%x", intf->channels[0].address);
>  	for (i = 1; i < IPMI_MAX_CHANNELS; i++)
>  		seq_printf(m, " %x", intf->channels[i].address);
> -	return seq_putc(m, '\n');
> +	seq_putc(m, '\n');
> +
> +	return 0;
>  }
>  
>  static int smi_ipmb_proc_open(struct inode *inode, struct file *file)
> diff --git a/fs/seq_file.c b/fs/seq_file.c
> index e6be05a..5ca5af9 100644
> --- a/fs/seq_file.c
> +++ b/fs/seq_file.c
> @@ -673,13 +673,14 @@ int seq_open_private(struct file *filp, const struct seq_operations *ops,
>  }
>  EXPORT_SYMBOL(seq_open_private);
>  
> -int seq_putc(struct seq_file *m, char c)
> +void seq_putc(struct seq_file *m, char c)
>  {
> -	if (m->count < m->size) {
> -		m->buf[m->count++] = c;
> -		return 0;
> +	if (m->count >= m->size) {
> +		seq_set_overflow(m);
> +		return;
>  	}
> -	return -1;
> +
> +	m->buf[m->count++] = c;
>  }
>  EXPORT_SYMBOL(seq_putc);
>  
> diff --git a/include/linux/seq_file.h b/include/linux/seq_file.h
> index 9b02cb6..c1e47ff 100644
> --- a/include/linux/seq_file.h
> +++ b/include/linux/seq_file.h
> @@ -115,7 +115,7 @@ ssize_t seq_read(struct file *, char __user *, size_t, loff_t *);
>  loff_t seq_lseek(struct file *, loff_t, int);
>  int seq_release(struct inode *, struct file *);
>  int seq_escape(struct seq_file *, const char *, const char *);
> -int seq_putc(struct seq_file *m, char c);
> +void seq_putc(struct seq_file *m, char c);
>  void seq_puts(struct seq_file *m, const char *s);
>  int seq_write(struct seq_file *seq, const void *data, size_t len);
>  
> diff --git a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4_compat.c b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4_compat.c
> index a460a87..f0dfe92 100644
> --- a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4_compat.c
> +++ b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4_compat.c
> @@ -300,7 +300,9 @@ static int exp_seq_show(struct seq_file *s, void *v)
>  		    __nf_ct_l3proto_find(exp->tuple.src.l3num),
>  		    __nf_ct_l4proto_find(exp->tuple.src.l3num,
>  					 exp->tuple.dst.protonum));
> -	return seq_putc(s, '\n');
> +	seq_putc(s, '\n');
> +
> +	return 0;
>  }
>  
>  static const struct seq_operations exp_seq_ops = {
> diff --git a/net/netfilter/nf_conntrack_expect.c b/net/netfilter/nf_conntrack_expect.c
> index 91a1837..7a17070 100644
> --- a/net/netfilter/nf_conntrack_expect.c
> +++ b/net/netfilter/nf_conntrack_expect.c
> @@ -561,7 +561,9 @@ static int exp_seq_show(struct seq_file *s, void *v)
>  				   helper->expect_policy[expect->class].name);
>  	}
>  
> -	return seq_putc(s, '\n');
> +	seq_putc(s, '\n');
> +
> +	return 0;
>  }
>  
>  static const struct seq_operations exp_seq_ops = {