Re: LPT versus nptl

On Mon, Apr 07, 2003 at 01:52:06PM -0500, Steven Munroe wrote:
> More problems with running LTP against nptl (PCC64). When we try to run 
> LPT most kernel tests fail with the message:
> 
> WARN : signal() failed for signal 32. error: 22 Invalid argument.
~> WARN : signal() failed for signal 33. error: 22 Invalid argument.
> 
> The root cause is that ltp/lib/tst_sig.c(tst_sig) sets up a signal 
> handler for each signal, except for specific signals where that is not 
> allowed. The problem is that which signals are "reserved" and how this 
> is enforced at runtime differs for linuxthreads and nptl.
> 
> For linuxthreads LTP tries to use the following:
> 
>         /*
>          * pthread-private signals SIGPTINTR and SIGPTRESCHED.
>          * Setting a handler for these signals is disallowed when
>          * the binary is linked against libpthread.
>          */
> #ifdef SIGPTINTR
>                 case SIGPTINTR:
> #endif /* SIGPTINTR */
> #ifdef SIGPTRESCHED
>                 case SIGPTRESCHED:
> #endif /* SIGPTRESCHED */
> 
> 	            break;
> 
> The first problem being that niether SIGPTINTR or SIGPTRESCHED is 
> defined, anywhere. However LPT does not fail for linuxthreads since it 
> does not enforce any restriction on int __pthread_sig_restart, 
> __pthread_sig_cancel, and __pthread_sig_debug unless the application is 
> actually threaded? (pthread__sigaction is envoked dynamically via 
> libc_maybe_call2, I think?)

I generally dodge this problem by skipping __SIGRTMIN <= sig <
SIGRTMIN.  Currently NPTL will use signals at the bottom of the range.

-- 
Daniel Jacobowitz
MontaVista Software                         Debian GNU/Linux Developer