On Thu, 2010-04-22 at 17:59 +0800, Dan Carpenter wrote:
> Hi Zhu Yi,
>
> This is a Smatch bug that has me a little puzzled.
>
> drivers/net/wireless/iwmc3200wifi/debugfs.c +447 iwm_debugfs_init(26)
> warn: 'iwm->dbg.devdir' dereferencing possible ERR_PTR()
>
> 440 iwm->dbg.devdir = debugfs_create_dir(devdir, iwm->dbg.rootdir);
> 441 result = PTR_ERR(iwm->dbg.devdir);
> 442 if (IS_ERR(iwm->dbg.devdir) && (result != -ENODEV)) {
> 443 IWM_ERR(iwm, "Couldn't create devdir: %d\n", result);
> 444 goto error;
> 445 }
> 446
> 447 iwm->dbg.dbgdir = debugfs_create_dir("debug", iwm->dbg.devdir);
>
> It looks like "iwm->dbg.devdir" could be ERR_PTR(-ENODEV) on line 447 and
> that would cause a problem inside debugfs_create_dir(). But at the same
> time -ENODEV was deliberately singled out as OK from other possible errors
> that debugfs_create_dir() can return.
We take -ENODEV for debugfs_create_dir if CONFIG_DEBUG_FS is not
enabled. We returns 0 deliberately in this case for rootdir create. I
agree we don't need to check it for the subdirs like we did now. But I
found lots of code don't even check (or don't use IS_ERR to check) the
return value of debugfs_create_dir. Maybe that's more problematic?
Thanks,
-yi
--
To unsubscribe from this list: send the line "unsubscribe linux-wireless" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
