Re: [Valgrind-users] 0 bytes inside a block of size 30,121

[Tom H. <to...@co...>]

On 26/03/16 19:15, Burlen Loring wrote:

> I like to understand better the following reports. I have a buffer that
> I allocated and that gets filled by MPI recv. However, for every access
> to the buffer valgrind produce a report similar to the following first
> report shown here:
>
>     Invalid read of size 4
>     Address 0x1788a6d0 is 0 bytes inside a block of size 30,121 alloc'd
>
> in subsequent reports "0 bytes inside" the 0 is replaced with the offset
> of the access in the buffer. Full output of the first few reports are
> shown below.

That does look odd. The only obvious way I can think of to get a report 
like that is if you had explicitly told valgrind to consider that memory 
as inaccessible with the VALGRIND_MAKE_MEM_NOACCESS call.

Tom

-- 
Tom Hughes (to...@co...)
http://compton.nu/