Re: [libvirt] [PATCH 3/3] virCommand: use procfs to learn opened FDs

On 7/15/19 9:26 AM, Florian Weimer wrote: > * Eric Blake: > >> On 7/14/19 12:23 AM, Florian Weimer wrote: >>> * Eric Blake: >>> >>>> Does anyone know if glibc guarantees that opendir/readdir in between >>>> multi-threaded fork() and exec() is safe, even though POSIX does not >>>> guarantee that safety in general? >>> >>> glibc supports malloc after multi-threaded fork as an extension (or as >>> a bug, because it makes malloc not async-signal-safe). >> >> It's not a bug for glibc to provide guarantees above what POSIX >> requires, but IS a bug for applications to depend on those guarantees >> without realizing they are non-portable. > > It's a bug because it makes malloc not async-signal-safe (as required by > POSIX) in our current implementation of malloc. Huh? malloc() is NOT required by POSIX to be async-signal-safe (it is NOT in the list at