On Tue, 2020-09-08 at 14:09 +0200, Mario Emmenlauer wrote: > 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. zlib is not used by the valgrind tools. In fact, valgrind tools do not use any library (even not libc).
The above newSuperblock trace shows that a *huge* block is requested. As this bug only happens when you use -ggdb3, this is likely a problem in the debuginfo reader of valgrind: some debug info generated by -ggdb3 is very probably not handled properly. I have recompiled libz with -ggdb3, but no problem when running this lib under valgrind. We might have a more clear idea of what happens on your side by adding some trace. The best is to file a bug on bugzilla, and attach the output of running valgrind with -d -d -d -v -v -v. That might give some information about what is wrong and possibly some more detailed trace can then be activated. Thanks Philippe _______________________________________________ Valgrind-users mailing list Valgrind-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/valgrind-users
