Messages in this thread |  | | Subject | Re: [PATCH] decompress_bunzip2: fix sizeof type in start_bunzip | From | Tom Rix <> | Date | Mon, 13 Jul 2020 12:27:02 -0700 |
| |
On 7/12/20 3:21 PM, hpa@zytor.com wrote: > 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.
Sorry, I am being pedantic, I mean anything that produces the correct assembly is correct. But there are different path to being correct. The path I was suggesting to follow the type of the element/final pointer when allocating an memory.
large_malloc(bd->dbufSize * sizeof(*bd->dbuf)) would also work
I will respin.
trix
|  |