* Russell King - ARM Linux <linux@xxxxxxxxxxxxxxxx> [130509 02:14]:
> So, I eliminated all but a very few of these from arch/arm, and I notice
> today that there's a new couple of instances introduced by:
Sorry I should have noticed that fnord, I had it in my muttrc but had
a an unnecessary \ in the expression so it did not work.
Here's a patch to fix the issue.
Hmm maybe we could redefine IS_ERR_OR_NULL as error in some ARM header
as long as drivers don't include it?
Regards,
Tony
From: Tony Lindgren <tony@xxxxxxxxxxx>
Date: Thu, 9 May 2013 08:27:25 -0700
Subject: [PATCH] ARM: OMAP2+: Remove bogus IS_ERR_OR_NULL checking from id.c
Commit 6770b211 (ARM: OMAP2+: Export SoC information to userspace)
had some broken return value handling as noted by Russell King:
+ soc_dev = soc_device_register(soc_dev_attr);
+ if (IS_ERR_OR_NULL(soc_dev)) {
+ kfree(soc_dev_attr);
+ return;
+ }
+
+ parent = soc_device_to_device(soc_dev);
+ if (!IS_ERR_OR_NULL(parent))
+ device_create_file(parent, &omap_soc_attr);
This is nonsense. For the first, IS_ERR() is sufficient. For the second,
tell me what error checking is required in the return value of this
function:
struct device *soc_device_to_device(struct soc_device *soc_dev)
{
return &soc_dev->dev;
}
when you've already determined that the passed soc_dev is a valid pointer.
If you read the comments against the prototype:
/**
* soc_device_to_device - helper function to fetch struct device
* @soc: Previously registered SoC device container
*/
struct device *soc_device_to_device(struct soc_device *soc);
if "soc" is valid, it means the "previously registered SoC device container"
must have succeeded and that can only happen if the struct device has been
registered. Ergo, there will always be a valid struct device pointer for
any registered SoC device container. Therefore, if soc_device_register()
succeeds, then the return value from soc_device_to_device() will always be
valid and no error checking of it is required.
Simples. The rule as ever applies here: get to know the APIs your using
and don't fumble around in the dark hoping that you'll get this stuff
right.
Fix it as noted by Russell.
Reported-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxxx>
Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx>
diff --git a/arch/arm/mach-omap2/id.c b/arch/arm/mach-omap2/id.c
index 9bc5a18..1272c41 100644
--- a/arch/arm/mach-omap2/id.c
+++ b/arch/arm/mach-omap2/id.c
@@ -648,13 +648,12 @@ void __init omap_soc_device_init(void)
soc_dev_attr->revision = soc_rev;
soc_dev = soc_device_register(soc_dev_attr);
- if (IS_ERR_OR_NULL(soc_dev)) {
+ if (IS_ERR(soc_dev)) {
kfree(soc_dev_attr);
return;
}
parent = soc_device_to_device(soc_dev);
- if (!IS_ERR_OR_NULL(parent))
- device_create_file(parent, &omap_soc_attr);
+ device_create_file(parent, &omap_soc_attr);
}
#endif /* CONFIG_SOC_BUS */
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