On Tuesday, September 24th, 2024 at 4:07 AM, Jiri Olsa <jolsa@xxxxxxxxxx> wrote: > > > With newly merged code the uprobe behaviour is slightly different > and affects uprobe consumer test. > > We no longer need to check if the uprobe object is still preserved > after removing last uretprobe, because it stays as long as there's > pending/installed uretprobe instance. > > This allows to run uretprobe consumers registered 'after' uprobe was > hit even if previous uretprobe got unregistered before being hit. > > The uprobe object will be now removed after the last uprobe ref is > released and in such case it's held by ri->uprobe (return instance) > > which is released after the uretprobe is hit. > > Reported-by: Ihor Solodrai ihor.solodrai@xxxxx > > Closes: https://lore.kernel.org/bpf/w6U8Z9fdhjnkSp2UaFaV1fGqJXvfLEtDKEUyGDkwmoruDJ_AgF_c0FFhrkeKW18OqiP-05s9yDKiT6X-Ns-avN_ABf0dcUkXqbSJN1TQSXo=@pm.me/ > Signed-off-by: Jiri Olsa jolsa@xxxxxxxxxx > > --- > .../testing/selftests/bpf/prog_tests/uprobe_multi_test.c | 9 +-------- > 1 file changed, 1 insertion(+), 8 deletions(-) > > diff --git a/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c b/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c > index 844f6fc8487b..c1ac813ff9ba 100644 > --- a/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c > +++ b/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c > @@ -869,21 +869,14 @@ static void consumer_test(struct uprobe_multi_consumers skel, > fmt = "prog 0/1: uprobe"; > } else { > / > - * uprobe return is tricky ;-) > - * > * to trigger uretprobe consumer, the uretprobe needs to be installed, > * which means one of the 'return' uprobes was alive when probe was hit: > * > * idxs: 2/3 uprobe return in 'installed' mask > - * > - * in addition if 'after' state removes everything that was installed in > - * 'before' state, then uprobe kernel object goes away and return uprobe > - * is not installed and we won't hit it even if it's in 'after' state. > / > unsigned long had_uretprobes = before & 0b1100; / is uretprobe installed / > - unsigned long probe_preserved = before & after; / did uprobe go away */ > > - if (had_uretprobes && probe_preserved && test_bit(idx, after)) > + if (had_uretprobes && test_bit(idx, after)) > val++; > fmt = "idx 2/3: uretprobe"; > } > -- > 2.46.0 Hi Jiri, I tested this change on top of bpf-next/master, and selftests/bpf/vmtest.sh passes. Thank you for the fix! Tested-by: Ihor Solodrai <ihor.solodrai@xxxxx>
