https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113082
--- Comment #5 from joseph at codesourcery dot com <joseph at codesourcery dot com> --- I think it would be reasonable for glibc to require that audit modules don't change errno, at least when acting for libc function calls where glibc guarantees not changing errno. I think user-provided IFUNC resolvers are only relevant for user-provided functions and so shouldn't be relevant to this issue (if a user declares their own function with a noerrno attribute, and also has an IFUNC resolver for that function, they need to make sure the IFUNC resolver behaves consistently with the attribute). It would also seem reasonable for glibc to guarantee that most string and memory functions (maybe excluding a few that involve the locale or other external state, such as strcoll or strerror, and definitely excluding those such as strdup that involve memory allocation) don't change errno. We may need to be careful about what "obviously" shouldn't affect errno (consider e.g. the ongoing discussions around qsort - where avoiding memory allocation should as a side effect also avoid affecting errno, but it's unclear how we might simultaneously avoid memory allocation, keep a stable sort, achieve O(n log(n)) worst case performance, and keep good performance for typical inputs).
