Public bug reported: I encountered regression failures running the gpsbabel test suite. The computed results differ if I run gpsbabel directly versus running gpsbabel under valgrind. I have only observed this problem on arm64. Note that this is not a problem with the output of valgrind, it is a problem with the output of the program run by valgrind.
I expect the output of a program to be identical if I run it with or without valgrind. I backported valgrind_3.23.0-0ubuntu2 to noble. It did not resolve the issue. I then created a ppa with the latest upstream version of valgrind, 3.24.0. This resolved the issue. The ppa is at https://launchpad.net/~tsteven4/+archive/ubuntu/valgrind-backports, version 1:3.24.0-0ubuntu1~noble11. As noted in the changelog I deleted the patch 11_arm64-cache-flush.patch because it conflicted with the upstream fix for the issue that necessitated the patch. I did not review the remaining patches to see if they have been resolved upstream, although I note several of them originated with the vendor and may or may not have been fixed upstream. The original regression failures were on: Description: Ubuntu 24.04.1 LTS Release: 24.04 valgrind: Installed: 1:3.22.0-0ubuntu3 Candidate: 1:3.22.0-0ubuntu3 Version table: *** 1:3.22.0-0ubuntu3 500 500 http://ports.ubuntu.com/ubuntu-ports noble/main arm64 Packages 100 /var/lib/dpkg/status ** Affects: valgrind (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2095501 Title: valgrind can compute incorrectly rounded results on arm64 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/valgrind/+bug/2095501/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs