Re: setrlimit hangs the process

[Rich Felker <dalias@libc.org>]

On Tue, Oct 09, 2018 at 09:37:06PM +0200, Rabbitstack wrote:
>  Should we raise an issue in Go upstream repository since there is nothing
> actionable from musl side?

Yes, I think so.

Rich


> El vie., 5 oct. 2018 2:47, Rich Felker <dalias@libc.org> escribió:
> 
> > On Thu, Oct 04, 2018 at 11:53:02AM -0400, Rich Felker wrote:
> > > On Thu, Oct 04, 2018 at 05:41:52PM +0200, Rabbitstack wrote:
> > > > Please use the following link to download strace since  daemon is
> > refusing
> > > > to deliver the mail.
> > > >
> > > > https://www.dropbox.com/s/syhbzxvijf7s4v1/agent.strace?dl=0
> > >
> > > Here is the bug:
> > >
> > > 6208  rt_sigprocmask(SIG_SETMASK, ~[HUP INT QUIT ILL TRAP ABRT BUS FPE
> > SEGV TERM STKFLT CHLD PROF SYS RTMIN RT_1],  <unfinished ...>
> > >
> > > Apparently Go has its own version of sigfillset, rather than calling
> > > the libc one, and it's hard-coded the glibc values for which signals
> > > are reserved for the implementation (just RTMIN and RT_1) rather than
> > > honoring SIGRTMIN (which resolves at runtime via a function call),
> > > which would exempt RT_2 from being blocked too.
> > >
> > > It needs to be fixed on the Go side. I'll look at it later if nobody
> > > else more familiar with Go gets to it sooner.
> >
> > If these are the right source files:
> >
> > https://golang.org/src/runtime/os_linux_generic.go#L33
> > https://golang.org/src/runtime/sys_linux_amd64.s#L290
> >
> > Then they're not even making any attempt to avoid stomping on
> > implementation-internal signals, and there's nothing musl could do to
> > prevent this. This suggests to me that something in your codebase is
> > explicitly avoiding RTMIN and RT_1 (33 and 34). Making it also avoid
> > RT_2 (35) would be a short-term hack you could use to get past this
> > problem, but there's no guarantee assignments won't change in the
> > future (this is why SIGRTMIN and SIGRTMAX macros expand to functions
> > calls). Really if a Go program wants to use libc, it needs to avoid
> > bypassing libc in ways that change the process state (like signal mask
> > or disposition).
> >
> > Rich
> >