On Sun, Aug 04, 2019 at 05:45:23AM +0000, Yonghong Song wrote:
>
>
> On 8/2/19 4:33 PM, Alexei Starovoitov wrote:
> > Add a test with multiple exit conditions.
> > It's not an infinite loop only when the verifier can properly track
> > all math on variable 'i' through all possible ways of executing this loop.
>
> Agreed with motivation of this test.
>
> >
> > barrier()s are needed to disable llvm optimization that combines multiple
> > branches into fewer branches.
> >
> > Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx>
> > ---
> > .../bpf/prog_tests/bpf_verif_scale.c | 1 +
> > tools/testing/selftests/bpf/progs/loop5.c | 37 +++++++++++++++++++
> > 2 files changed, 38 insertions(+)
> > create mode 100644 tools/testing/selftests/bpf/progs/loop5.c
> >
> > diff --git a/tools/testing/selftests/bpf/prog_tests/bpf_verif_scale.c b/tools/testing/selftests/bpf/prog_tests/bpf_verif_scale.c
> > index 757e39540eda..29615a4a9362 100644
> > --- a/tools/testing/selftests/bpf/prog_tests/bpf_verif_scale.c
> > +++ b/tools/testing/selftests/bpf/prog_tests/bpf_verif_scale.c
> > @@ -72,6 +72,7 @@ void test_bpf_verif_scale(void)
> > { "loop1.o", BPF_PROG_TYPE_RAW_TRACEPOINT },
> > { "loop2.o", BPF_PROG_TYPE_RAW_TRACEPOINT },
> > { "loop4.o", BPF_PROG_TYPE_RAW_TRACEPOINT }, > + { "loop5.o", BPF_PROG_TYPE_RAW_TRACEPOINT },
>
> More like a BPF_PROG_TYPE_SCHED_CLS type although probably it does not
> matter as we did not attach it to anywhere?
right. will fix.
> >
> > /* partial unroll. 19k insn in a loop.
> > * Total program size 20.8k insn.
> > diff --git a/tools/testing/selftests/bpf/progs/loop5.c b/tools/testing/selftests/bpf/progs/loop5.c
> > new file mode 100644
> > index 000000000000..9d9817efe208
> > --- /dev/null
> > +++ b/tools/testing/selftests/bpf/progs/loop5.c
> > @@ -0,0 +1,37 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +// Copyright (c) 2019 Facebook
> > +#include <linux/sched.h>
> > +#include <linux/ptrace.h>
>
> The above headers probably not needed.
will fix
