On Mon, 2021-03-08 at 10:50 +0000, Daniel P. Berrangé wrote:
> On Fri, Mar 05, 2021 at 08:13:59PM +0100, Andrea Bolognani wrote:
> > + if (!(label = virProcessLimitResourceToLabel(resource))) {
> > + virReportError(VIR_ERR_INTERNAL_ERROR,
> > + _("Unknown resource %d requested for process %lld"),
> > + resource, (long long)pid);
> > + return -1;
>
> Setting errors on -1
This is only hit if virProcessGetLimitFromProc() has been asked to
obtain limits for a resource it doesn't know how to fetch, which
indicates a bug in libvirt and is thus reported as internal error.
> > + procfile = g_strdup_printf("/proc/%lld/limits", (long long)pid);
> > +
> > + if (!g_file_get_contents(procfile, &buf, &len, NULL))
> > + return -1;
>
> Not setting errors on -1
This is simply "file couldn't be read", which would be the case on
FreeBSD for example.
> > + /* For whatever reason, using prlimit() on another process - even
> > + * when it's just to obtain the current limit rather than changing
> > + * it - requires CAP_SYS_RESOURCE, which we might not have in a
> > + * containerized environment; on the other hand, no particular
> > + * permission is needed to poke around /proc, so try that if going
> > + * through the syscall didn't work */
> > + if (virProcessGetLimitFromProc(pid, resource, old_limit) == 0)
> > + return 0;
>
> This ought to be conditional for Linux only and error reporting needs
> to be made consistent.
The intent above was to have this fail quietly on non-Linux without
adding checks for it, but sure I can have an actual stub on other
platforms instead.
--
Andrea Bolognani / Red Hat / Virtualization
