[PATCH v6 1/3] Introduce seccomp-assisted syscall filtering

[Paul Chaignon]

On Mon, Sep 23, 2019 at 12:22:09AM +0300, Dmitry V. Levin wrote:
> On Mon, Sep 23, 2019 at 12:00:54AM +0300, Dmitry V. Levin wrote:
> > On Sun, Sep 22, 2019 at 10:13:29PM +0200, Paul Chaignon wrote:
> [...]
> > > +	if (seccomp_filtering) {
> > > +		if ((opt_p && !argc) || debug_flag)
> > 
> > I think we can avoid introducing opt_p and check nprocs instead.
> > 
> > > +			error_msg("-n is ineffective on processes attached with -p");
> > 
> > It's not just ineffective, it's not enabled for these processes.
> 
> Looks like it makes sense to print diagnostics regardless of argc and
> debug_flag.

Since strace -fn -p $(pidof ...) cmd is a legitimate use of strace and the
new feature, I thought we might not want to print a warning every single
time someone uses that command.  That's why I switched to a debug message
when both -p and cmd are used.

Paul