On a Monday in 2026, Peter Krempa via Devel wrote:
G_REGEX_OPTIMIZE invokes PCRE's JIT optimizer for regexes which requires writable executable memory. This clashes with the 'execmem' SELinux permission which we don't really want to grant to any of the virt daemons.
Since all uses of G_REGEX_OPTIMIZE are on code paths unlikely to hit the ~3x performance penalty of using interpeted evaluation of the regex rather than the JIT'd one we can simply remove the optimization from the rest of the calls. (Only 3 of 10 used it).
Patch 2 is optional; selinux can simply ban 'execmem' and mark it as 'dontaudit'. glib will fall back to the interpreter.
The patches are based on a discussion which I've summarized in: https://redhat.atlassian.net/browse/RHEL-44901
Peter Krempa (2): syntax-check: Add warning about implications of G_REGEX_OPTIMIZE Avoid use of glib's G_REGEX_OPTIMIZE flag
Reviewed-by: Ján Tomko <jtomko@redhat.com> Jano