Re: [PATCH] decompress_bunzip2: fix sizeof type in start_bunzip

[hpa@zytor.com]

On July 12, 2020 8:12:43 AM PDT, Tom Rix <trix@redhat.com> wrote:
>
>On 7/12/20 6:09 AM, H. Peter Anvin wrote:
>> On 2020-07-12 05:59, trix@redhat.com wrote:
>>> From: Tom Rix <trix@redhat.com>
>>>
>>> clang static analysis flags this error
>>>
>>> lib/decompress_bunzip2.c:671:13: warning: Result of 'malloc' is
>converted
>>>   to a pointer of type 'unsigned int', which is incompatible with
>sizeof
>>>   operand type 'int' [unix.MallocSizeof]
>>>         bd->dbuf = large_malloc(bd->dbufSize * sizeof(int));
>>>                    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>>
>>> Reviewing the bunzip_data structure, the element dbuf is type
>>>
>>> 	/* Intermediate buffer and its size (in bytes) */
>>> 	unsigned int *dbuf, dbufSize;
>>>
>>> So change the type in sizeof to 'unsigned int'
>>>
>> You must be kidding.
>>
>> If you want to change it, change it to sizeof(bd->dbuf) instead, but
>this flag
>> is at least in my opinion a total joke. For sizeof(int) !=
>sizeof(unsigned
>> int) is beyond bizarre, no matter how stupid the platform.
>
>Using the actual type is more correct that using a type of the same
>size.
>
>trix
>
>> 	-hpa
>>

"More correct?" All it is is more verbose.

Using the sizeof of the actual object at least adds some actual safety.
-- 
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