Re: valgrind always fails with out of memory

On 08.09.20 12:25, Mario Emmenlauer wrote:
> 
> On 08.09.20 12:04, Mario Emmenlauer wrote:
>> The error I get most frequently is (full output attached in log.txt)
>> ==32==     Valgrind's memory management: out of memory:
>> ==32==        newSuperblock's request for 6864695621860790272 bytes failed.
>> ==32==          114,106,368 bytes have already been mmap-ed ANONYMOUS.
> 
> Argh! After sending the email, I went through the stack trace for
> the hundredth time, and spotted the use of "zlib". And indeed, when
> replacing my own zlib 1.2.11 with the system zlib 1.2.11, valgrind
> works as expected!
> 
> Does that make sense? Is zlib used by valgrind itself? And why could
> my debug build differ (so much) from the system zlib that it breaks
> valgrind? I double-checked and its the identical source code from
> Ubuntu, just missing two or three patches.

So it seems I can (partially) answer my own question: when valgrind
is used on an executable that links zlib built with -ggdb3, then it
does not work (due to aforementioned error). Keeping all other debug-
settings except -ggdb3 works still fine.

I have no clue as to _why_ this may happen, but I hope it can be
helpful to other people running into the same issue.

All the best,

    Mario Emmenlauer