From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752660Ab0CRXs5 (ORCPT ); Thu, 18 Mar 2010 19:48:57 -0400 Received: from mgw2.diku.dk ([130.225.96.92]:60740 "EHLO mgw2.diku.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752451Ab0CRXsy (ORCPT ); Thu, 18 Mar 2010 19:48:54 -0400 Date: Fri, 19 Mar 2010 00:48:51 +0100 (CET) From: Julia Lawall To: Andrew Morton Cc: Zhang Rui , Len Brown , linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: Re: [PATCH 4/6] drivers/acpi: Use kasprintf In-Reply-To: <20100318162529.762251ef.akpm@linux-foundation.org> Message-ID: References: <20100318162529.762251ef.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 18 Mar 2010, Andrew Morton wrote: > On Wed, 10 Mar 2010 22:16:51 +0100 (CET) > Julia Lawall wrote: > > > From: Julia Lawall > > > > kasprintf combines kmalloc and sprintf, and takes care of the size > > calculation itself. > > > > The semantic patch that makes this change is as follows: > > (http://coccinelle.lip6.fr/) > > > > // > > @@ > > expression a,flag; > > expression list args; > > statement S; > > @@ > > > > a = > > - \(kmalloc\|kzalloc\)(...,flag) > > + kasprintf(flag,args) > > <... when != a > > if (a == NULL || ...) S > > ...> > > - sprintf(a,args); > > // > > > > Signed-off-by: Julia Lawall > > > > --- > > drivers/acpi/video.c | 6 ++---- > > 1 file changed, 2 insertions(+), 4 deletions(-) > > > > diff -u -p a/drivers/acpi/video.c b/drivers/acpi/video.c > > --- a/drivers/acpi/video.c > > +++ b/drivers/acpi/video.c > > @@ -1005,11 +1005,10 @@ static void acpi_video_device_find_cap(s > > result = acpi_video_init_brightness(device); > > if (result) > > return; > > - name = kzalloc(MAX_NAME_LEN, GFP_KERNEL); > > + name = kasprintf(GFP_KERNEL, "acpi_video%d", count++); > > if (!name) > > return; > > > > - sprintf(name, "acpi_video%d", count++); > > device->backlight = backlight_device_register(name, > > NULL, device, &acpi_backlight_ops); > > kfree(name); > > @@ -1056,10 +1055,9 @@ static void acpi_video_device_find_cap(s > > if (device->cap._DCS && device->cap._DSS) { > > static int count; > > char *name; > > - name = kzalloc(MAX_NAME_LEN, GFP_KERNEL); > > + name = kasprintf(GFP_KERNEL, "acpi_video%d", count++); > > if (!name) > > return; > > - sprintf(name, "acpi_video%d", count++); > > device->output_dev = video_output_register(name, > > NULL, device, &acpi_output_properties); > > kfree(name); > > It's not an equivalent change - if the memory allocation fails, this > patch will now cause `count' to be incremented anyway, presumably > leaving a gap in the enumeration. Indeed. What is below looks better. julia > I don't know if that matters. If so, this: > > --- a/drivers/acpi/video.c~drivers-acpi-use-kasprintf-fix > +++ a/drivers/acpi/video.c > @@ -1006,9 +1006,10 @@ static void acpi_video_device_find_cap(s > result = acpi_video_init_brightness(device); > if (result) > return; > - name = kasprintf(GFP_KERNEL, "acpi_video%d", count++); > + name = kasprintf(GFP_KERNEL, "acpi_video%d", count); > if (!name) > return; > + count++; > > memset(&props, 0, sizeof(struct backlight_properties)); > props.max_brightness = device->brightness->count - 3; > @@ -1058,9 +1059,10 @@ static void acpi_video_device_find_cap(s > if (device->cap._DCS && device->cap._DSS) { > static int count; > char *name; > - name = kasprintf(GFP_KERNEL, "acpi_video%d", count++); > + name = kasprintf(GFP_KERNEL, "acpi_video%d", count); > if (!name) > return; > + count++; > device->output_dev = video_output_register(name, > NULL, device, &acpi_output_properties); > kfree(name); > _ > > -- > To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >