Re: Possible coding issue in udf??

From: Andreas Dilger
Date: Sun May 15 2011 - 12:56:37 EST


On 2011-05-15, at 9:14 AM, Andi Kleen <andi@xxxxxxxxxxxxxx> wrote:
> Alex Davis <alex14641@xxxxxxxxx> writes:
>> In fs/udf/inode.c, line 1455, linux 2.6.35, there is the following code:
>>
>> udfperms = ((inode->i_mode & S_IRWXO)) |
>> ((inode->i_mode & S_IRWXG) << 2) |
>> ((inode->i_mode & S_IRWXU) << 4);
>>
>> Shouldn't we be shifting by 3 bits? i.e:
>> udfperms = ((inode->i_mode & S_IRWXO)) |
>> ((inode->i_mode & S_IRWXG) << 3) |
>> ((inode->i_mode & S_IRWXU) << 6);
>>
>> The S_I.. constants are all defined in include/linux/stat.h as 3-bit values.
>>
>> I will send a patch if needed.
>
> I would suggest you test it first. Put in a UDF disk that triggers
> this case (verify with a printk). Check in ls -l if the
> permissions are correct or wrong.

Typically I would agree. In this case ir looks like the existing code doesn't make sense, because it will be overlapping the R and X bits from the adjacent U, G, and O masks.

Cheers, Andreas--
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