Re: [Xenomai] [Xenomai-git] Jan Kiszka : lib/cobalt: Rework minimum stack size enforcement

[Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>]

On Tue, Apr 21, 2015 at 06:04:42PM +0200, Jan Kiszka wrote:
> On 2015-04-21 17:27, Gilles Chanteperdrix wrote:
> > On Tue, Apr 21, 2015 at 05:22:34PM +0200, git repository hosting wrote:
> >> +COBALT_IMPL(int, pthread_attr_setstack, (pthread_attr_t *attr, void *stackaddr,
> >> +					 size_t stacksize))
> >> +{
> >> +	if (stacksize < COBALT_STACKSIZE_MIN)
> >> +		return -EINVAL;
> >> +	return __STD(pthread_attr_setstack)(attr, stackaddr, stacksize);
> >> +}
> > 
> > As I said, there is no reason for Xenomai to enforce a task size
> > larger than PTHREAD_STACK_MIN. This breaks POSIX compliance, and is
> > useless.
> 
> Then we should not use printf & Co. from any trampoline function, e.g.
> vxworks/taskLib.c:task_trampoline. I only tried with a local skin, but I
> bet the issue is reproducible with that one.
> 
> For that reason, I went down the conservative path.

The path you took breaks compatibility with POSIX. On a compliant
system, pthread_attr_setstacksize(attr, PTHREAD_STACK_MIN) is not
supposed to return an error.

-- 
					    Gilles.