[DTrace-devel] [PATCH] uprobe: do not call populate_args() for pid probes

[Kris Van Hees]

On Thu, Aug 14, 2025 at 12:47:25PM -0400, Eugene Loh wrote:
> Reviewed-by: Eugene Loh <eugene.loh at oracle.com>
> 
> FWIW, with every patch I wonder:  "Are there any test issues?" (Like, should
> we test something here?  Were we?  Etc.)  I assume in this particular case,
> problems were revealed by patch "Fix various memory leaks related to stapsdt
> and usdt probes" on tests
>     test/unittest/usdt/tst.pidargmap.sh
>     test/unittest/usdt/tst.pidargs.sh
>     test/unittest/usdt/tst.pidprobes.sh
> The present patch is simply to remediate those revealed problems. To me,
> that sort of information is useful in a commit message.

I can add that in the future, though personally I don't find that as valuable
because anyone would have run a test prior to this patch and after the patch,
would notice that anyway.

But if it makes it easier to assess a patch, etc then I can add that in the
future.

> On 8/13/25 23:58, Kris Van Hees via DTrace-devel wrote:
> > Only USDT (regular and is-enabled) probes need populate_args().
> > 
> > Signed-off-by: Kris Van Hees <kris.van.hees at oracle.com>
> > ---
> >   libdtrace/dt_prov_uprobe.c | 6 ++++--
> >   1 file changed, 4 insertions(+), 2 deletions(-)
> > 
> > diff --git a/libdtrace/dt_prov_uprobe.c b/libdtrace/dt_prov_uprobe.c
> > index c63d58383..605ae8397 100644
> > --- a/libdtrace/dt_prov_uprobe.c
> > +++ b/libdtrace/dt_prov_uprobe.c
> > @@ -994,8 +994,10 @@ static dt_probe_t *create_underlying(dtrace_hdl_t *dtp,
> >   		 */
> >   	}
> > -	if (populate_args(dtp, psp, upp) < 0)
> > -		goto fail;
> > +	if (upp->flags & (PP_IS_ENABLED | PP_IS_USDT)) {
> > +		if (populate_args(dtp, psp, upp) < 0)
> > +			goto fail;
> > +	}
> >   	return uprp;