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Message-Id: <1206433881.3047.51.camel@acpi-hp-zz.sh.intel.com>
Date: Tue, 25 Mar 2008 16:31:21 +0800
From: "Zhang, Rui" <rui.zhang@...el.com>
To: Julia Lawall <julia@...u.dk>
Cc: "Brown, Len" <len.brown@...el.com>, linux-acpi@...r.kernel.org,
linux-kernel@...r.kernel.org, kernel-janitors@...r.kernel.org
Subject: Re: [PATCH 4/5] drivers/acpi: elide a non-zero test on a result
that is never 0
On Tue, 2008-03-25 at 02:10 +0800, Julia Lawall wrote:
> From: Julia Lawall <julia@...u.dk>
>
> The function thermal_cooling_device_register always returns either a
> valid
> pointer or a value made with ERR_PTR, so a test for non-zero on the
> result
> will always succeed.
>
>
> The problem was found using the following semantic match.
> (http://www.emn.fr/x-info/coccinelle/)
>
> //<smpl>
> @a@
> expression E, E1;
> statement S,S1;
> position p;
> @@
>
> E = thermal_cooling_device_register(...)
> ... when != E = E1
> if@p (E) S else S1
>
> @n@
> position a.p;
> expression E,E1;
> statement S,S1;
> @@
>
> E = NULL
> ... when != E = E1
> if@p (E) S else S1
>
> @depends on !n@
> expression E;
> statement S,S1;
> position a.p;
> @@
>
> * if@p (E)
> S else S1
> //</smpl>
>
> Signed-off-by: Julia Lawall <julia@...u.dk>
Signed-off-by: Zhang Rui <rui.zhang@...el.com>
> ---
> drivers/acpi/fan.c | 34
> ++++++++++++++++------------------
> drivers/acpi/processor_core.c | 30 ++++++++++++++----------------
> drivers/acpi/video.c | 28 +++++++++++++---------------
> 3 files changed, 43 insertions(+), 49 deletions(-)
>
> diff -u -p a/drivers/acpi/fan.c b/drivers/acpi/fan.c
> --- a/drivers/acpi/fan.c 2008-03-12 14:13:13.000000000 +0100
> +++ b/drivers/acpi/fan.c 2008-03-24 16:14:50.000000000 +0100
> @@ -260,24 +260,22 @@ static int acpi_fan_add(struct acpi_devi
> result = PTR_ERR(cdev);
> goto end;
> }
> - if (cdev) {
> - printk(KERN_INFO PREFIX
> - "%s is registered as cooling_device%d\n",
> - device->dev.bus_id, cdev->id);
> -
> - acpi_driver_data(device) = cdev;
> - result = sysfs_create_link(&device->dev.kobj,
> - &cdev->device.kobj,
> - "thermal_cooling");
> - if (result)
> - return result;
> -
> - result = sysfs_create_link(&cdev->device.kobj,
> - &device->dev.kobj,
> - "device");
> - if (result)
> - return result;
> - }
> + printk(KERN_INFO PREFIX
> + "%s is registered as cooling_device%d\n",
> + device->dev.bus_id, cdev->id);
> +
> + acpi_driver_data(device) = cdev;
> + result = sysfs_create_link(&device->dev.kobj,
> + &cdev->device.kobj,
> + "thermal_cooling");
> + if (result)
> + return result;
> +
> + result = sysfs_create_link(&cdev->device.kobj,
> + &device->dev.kobj,
> + "device");
> + if (result)
> + return result;
>
> result = acpi_fan_add_fs(device);
> if (result)
> diff -u -p a/drivers/acpi/processor_core.c
> b/drivers/acpi/processor_core.c
> --- a/drivers/acpi/processor_core.c 2008-03-12 14:13:13.000000000
> +0100
> +++ b/drivers/acpi/processor_core.c 2008-03-24 16:15:53.000000000
> +0100
> @@ -674,22 +674,20 @@ static int __cpuinit acpi_processor_star
> result = PTR_ERR(pr->cdev);
> goto end;
> }
> - if (pr->cdev) {
> - printk(KERN_INFO PREFIX
> - "%s is registered as cooling_device%d\n",
> - device->dev.bus_id, pr->cdev->id);
> -
> - result = sysfs_create_link(&device->dev.kobj,
> - &pr->cdev->device.kobj,
> - "thermal_cooling");
> - if (result)
> - return result;
> - result = sysfs_create_link(&pr->cdev->device.kobj,
> - &device->dev.kobj,
> - "device");
> - if (result)
> - return result;
> - }
> + printk(KERN_INFO PREFIX
> + "%s is registered as cooling_device%d\n",
> + device->dev.bus_id, pr->cdev->id);
> +
> + result = sysfs_create_link(&device->dev.kobj,
> + &pr->cdev->device.kobj,
> + "thermal_cooling");
> + if (result)
> + return result;
> + result = sysfs_create_link(&pr->cdev->device.kobj,
> + &device->dev.kobj,
> + "device");
> + if (result)
> + return result;
>
> if (pr->flags.throttling) {
> printk(KERN_INFO PREFIX "%s [%s] (supports",
> diff -u -p a/drivers/acpi/video.c b/drivers/acpi/video.c
> --- a/drivers/acpi/video.c 2008-03-12 14:13:13.000000000 +0100
> +++ b/drivers/acpi/video.c 2008-03-24 16:17:17.000000000 +0100
> @@ -734,21 +734,19 @@ static void acpi_video_device_find_cap(s
> if (IS_ERR(device->cdev))
> return;
>
> - if (device->cdev) {
> - printk(KERN_INFO PREFIX
> - "%s is registered as cooling_device%d
> \n",
> - device->dev->dev.bus_id,
> device->cdev->id);
> - result =
> sysfs_create_link(&device->dev->dev.kobj,
> - &device->cdev->device.kobj,
> - "thermal_cooling");
> - if (result)
> - printk(KERN_ERR PREFIX "Create sysfs
> link\n");
> - result =
> sysfs_create_link(&device->cdev->device.kobj,
> - &device->dev->dev.kobj,
> - "device");
> - if (result)
> - printk(KERN_ERR PREFIX "Create sysfs
> link\n");
> - }
> + printk(KERN_INFO PREFIX
> + "%s is registered as cooling_device%d\n",
> + device->dev->dev.bus_id, device->cdev->id);
> + result = sysfs_create_link(&device->dev->dev.kobj,
> + &device->cdev->device.kobj,
> + "thermal_cooling");
> + if (result)
> + printk(KERN_ERR PREFIX "Create sysfs link\n");
> + result = sysfs_create_link(&device->cdev->device.kobj,
> + &device->dev->dev.kobj,
> + "device");
> + if (result)
> + printk(KERN_ERR PREFIX "Create sysfs link\n");
> }
> if (device->cap._DCS && device->cap._DSS){
> static int count = 0;
> --
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