linuxppc-dev.lists.ozlabs.org archive mirror
 help / color / mirror / Atom feed
From: roel kluin <roel.kluin@gmail.com>
To: benh@kernel.crashing.org, linuxppc-dev@ozlabs.org,
	linux-kernel@vger.kernel.org
Subject: powerpc: hv{cs, si}_close() both unsigned hp->count and hvcsd->open_count cannot be negative
Date: Sat, 29 Nov 2008 05:57:33 -0500	[thread overview]
Message-ID: <4931201D.7060701@gmail.com> (raw)

unsigned hp->count and hvcsd->open_count cannot be negative

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
---
Both members of respectively struct hvcs_struct, see
vi drivers/char/hvcs.c +262

and struct hvcs_struct, see
vi drivers/char/hvsi.c +70

diff --git a/drivers/char/hvcs.c b/drivers/char/hvcs.c
index 473d9b1..b228b84 100644
--- a/drivers/char/hvcs.c
+++ b/drivers/char/hvcs.c
@@ -1222,7 +1222,8 @@ static void hvcs_close(struct tty_struct *tty, struct file *filp)
 	hvcsd = tty->driver_data;
 
 	spin_lock_irqsave(&hvcsd->lock, flags);
-	if (--hvcsd->open_count == 0) {
+	if (hvcsd->open_count == 1) {
+		hvcsd->open_count--;
 
 		vio_disable_interrupts(hvcsd->vdev);
 
@@ -1248,7 +1249,9 @@ static void hvcs_close(struct tty_struct *tty, struct file *filp)
 		free_irq(irq, hvcsd);
 		kref_put(&hvcsd->kref, destroy_hvcs_struct);
 		return;
-	} else if (hvcsd->open_count < 0) {
+	} else if (hvcsd->open_count > 1) {
+		hvcsd->open_count--;
+	} else {
 		printk(KERN_ERR "HVCS: vty-server@%X open_count: %d"
 				" is missmanaged.\n",
 		hvcsd->vdev->unit_address, hvcsd->open_count);
diff --git a/drivers/char/hvsi.c b/drivers/char/hvsi.c
index 59c6f9a..d46bccd 100644
--- a/drivers/char/hvsi.c
+++ b/drivers/char/hvsi.c
@@ -875,7 +875,8 @@ static void hvsi_close(struct tty_struct *tty, struct file *filp)
 
 	spin_lock_irqsave(&hp->lock, flags);
 
-	if (--hp->count == 0) {
+	if (hp->count == 1) {
+		hp->count--;
 		hp->tty = NULL;
 		hp->inbuf_end = hp->inbuf; /* discard remaining partial packets */
 
@@ -908,7 +909,9 @@ static void hvsi_close(struct tty_struct *tty, struct file *filp)
 
 			spin_lock_irqsave(&hp->lock, flags);
 		}
-	} else if (hp->count < 0)
+	} else if (hp->count > 1)
+		hp->count--;
+	else
 		printk(KERN_ERR "hvsi_close %lu: oops, count is %d\n",
 		       hp - hvsi_ports, hp->count);
 

             reply	other threads:[~2008-11-29 10:57 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-11-29 10:57 roel kluin [this message]
2008-11-29 12:54 ` powerpc: hv{cs, si}_close() both unsigned hp->count and hvcsd->open_count cannot be negative Andreas Schwab
2008-11-29 13:27   ` roel kluin
2008-11-29 15:01     ` Andreas Schwab
2008-11-29 23:20 ` Paul Mackerras
2008-11-30 11:16   ` Alan Cox
2008-11-30 21:23     ` Paul Mackerras

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=4931201D.7060701@gmail.com \
    --to=roel.kluin@gmail.com \
    --cc=benh@kernel.crashing.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linuxppc-dev@ozlabs.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).