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Subject[PATCH 5/5] drivers/misc: elide a non-zero test on a result that is never 0
From: Julia Lawall <julia@diku.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@diku.dk>
---
drivers/misc/intel_menlow.c | 24 +++++++++++-------------
1 file changed, 11 insertions(+), 13 deletions(-)

diff -u -p a/drivers/misc/intel_menlow.c b/drivers/misc/intel_menlow.c
--- a/drivers/misc/intel_menlow.c 2008-03-12 14:13:13.000000000 +0100
+++ b/drivers/misc/intel_menlow.c 2008-03-24 16:18:06.000000000 +0100
@@ -175,19 +175,17 @@ static int intel_menlow_memory_add(struc
goto end;
}

- if (cdev) {
- acpi_driver_data(device) = cdev;
- result = sysfs_create_link(&device->dev.kobj,
- &cdev->device.kobj, "thermal_cooling");
- if (result)
- goto unregister;
-
- result = sysfs_create_link(&cdev->device.kobj,
- &device->dev.kobj, "device");
- if (result) {
- sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
- goto unregister;
- }
+ acpi_driver_data(device) = cdev;
+ result = sysfs_create_link(&device->dev.kobj,
+ &cdev->device.kobj, "thermal_cooling");
+ if (result)
+ goto unregister;
+
+ result = sysfs_create_link(&cdev->device.kobj,
+ &device->dev.kobj, "device");
+ if (result) {
+ sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
+ goto unregister;
}

end:

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