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From: David Brownell <david-b-yBeKhBN/0LDR7s880joybQ@public.gmane.org>
To: i2c-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org
Subject: [patch 2.6.26-rc1] i2c_use_client() defends against NULL
Date: Sun, 4 May 2008 13:06:20 -0700	[thread overview]
Message-ID: <200805041306.21074.david-b@pacbell.net> (raw)

Defend the i2c refcount calls against NULL pointers, as is important
(and conventional) for such calls ... we don't want to morph NULL
pointers into bogus non-null ones.  Note that none of the current
callers of i2c_use_client() use its return value.

Signed-off-by: David Brownell <dbrownell-Rn4VEauK+AKRv+LV9MX5uipxlwaOVQ5f@public.gmane.org>
---
 drivers/i2c/i2c-core.c |    8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

--- g26.orig/drivers/i2c/i2c-core.c	2008-05-04 12:50:33.000000000 -0700
+++ g26/drivers/i2c/i2c-core.c	2008-05-04 12:51:04.000000000 -0700
@@ -1013,8 +1013,9 @@ EXPORT_SYMBOL(i2c_detach_client);
  */
 struct i2c_client *i2c_use_client(struct i2c_client *client)
 {
-	get_device(&client->dev);
-	return client;
+	if (client && get_device(&client->dev))
+		return client;
+	return NULL;
 }
 EXPORT_SYMBOL(i2c_use_client);
 
@@ -1026,7 +1027,8 @@ EXPORT_SYMBOL(i2c_use_client);
  */
 void i2c_release_client(struct i2c_client *client)
 {
-	put_device(&client->dev);
+	if (client)
+		put_device(&client->dev);
 }
 EXPORT_SYMBOL(i2c_release_client);
 

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             reply	other threads:[~2008-05-04 20:06 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-05-04 20:06 David Brownell [this message]
     [not found] ` <200805041306.21074.david-b-yBeKhBN/0LDR7s880joybQ@public.gmane.org>
2008-05-17 12:40   ` [patch 2.6.26-rc1] i2c_use_client() defends against NULL Jean Delvare
     [not found]     ` <20080517144007.7611ab32-ig7AzVSIIG7kN2dkZ6Wm7A@public.gmane.org>
2008-05-17 13:57       ` David Brownell
     [not found]         ` <200805170657.56833.david-b-yBeKhBN/0LDR7s880joybQ@public.gmane.org>
2008-05-17 17:53           ` Trent Piepho
     [not found]             ` <Pine.LNX.4.58.0805171048070.4196-13q4cmjDBaTP3RPoUHIrnuTW4wlIGRCZ@public.gmane.org>
2008-05-17 18:53               ` David Brownell

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