On Thu, Nov 17, 2022 at 3:58 PM Kumar Kartikeya Dwivedi
<memxor@xxxxxxxxx> wrote:
>
> On Fri, Nov 18, 2022 at 04:57:50AM IST, Dave Marchevsky wrote:
> > On 11/17/22 6:05 PM, Alexei Starovoitov wrote:
> > > On Thu, Nov 17, 2022 at 2:56 PM Kumar Kartikeya Dwivedi
> > > <memxor@xxxxxxxxx> wrote:
> > >>
> > >> Include various tests covering the success and failure cases. Also, run
> > >> the success cases at runtime to verify correctness of linked list
> > >> manipulation routines, in addition to ensuring successful verification.
> > >>
> > >> Signed-off-by: Kumar Kartikeya Dwivedi <memxor@xxxxxxxxx>
> > >> ---
> >
> > [...]
> >
> > >> diff --git a/tools/testing/selftests/bpf/progs/linked_list.h b/tools/testing/selftests/bpf/progs/linked_list.h
> > >> new file mode 100644
> > >> index 000000000000..8db80ed64db1
> > >> --- /dev/null
> > >> +++ b/tools/testing/selftests/bpf/progs/linked_list.h
> > >> @@ -0,0 +1,56 @@
> > >> +// SPDX-License-Identifier: GPL-2.0
> > >> +#ifndef LINKED_LIST_H
> > >> +#define LINKED_LIST_H
> > >> +
> > >> +#include <vmlinux.h>
> > >> +#include <bpf/bpf_helpers.h>
> > >> +#include "bpf_experimental.h"
> > >> +
> > >> +struct bar {
> > >> + struct bpf_list_node node;
> > >> + int data;
> > >> +};
> > >> +
> > >> +struct foo {
> > >> + struct bpf_list_node node;
> > >> + struct bpf_list_head head __contains(bar, node);
> > >> + struct bpf_spin_lock lock;
> > >> + int data;
> > >> + struct bpf_list_node node2;
> > >> +};
> > >> +
> > >> +struct map_value {
> > >> + struct bpf_spin_lock lock;
> > >> + int data;
> > >> + struct bpf_list_head head __contains(foo, node);
> > >> +};
> > >> +
> > >> +struct array_map {
> > >> + __uint(type, BPF_MAP_TYPE_ARRAY);
> > >> + __type(key, int);
> > >> + __type(value, struct map_value);
> > >> + __uint(max_entries, 1);
> > >> +};
> > >> +
> > >> +struct array_map array_map SEC(".maps");
> > >> +struct array_map inner_map SEC(".maps");
> > >> +
> > >> +struct {
> > >> + __uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS);
> > >> + __uint(max_entries, 1);
> > >> + __type(key, int);
> > >> + __type(value, int);
> > >> + __array(values, struct array_map);
> > >> +} map_of_maps SEC(".maps") = {
> > >> + .values = {
> > >> + [0] = &inner_map,
> > >> + },
> > >> +};
> > >> +
> > >> +#define private(name) SEC(".data." #name) __hidden __attribute__((aligned(8)))
> > >> +
> > >> +private(A) struct bpf_spin_lock glock;
> > >> +private(A) struct bpf_list_head ghead __contains(foo, node);
> > >> +private(B) struct bpf_spin_lock glock2;
> > >
> > > The latest llvm crashes with a bug here:
> > >
> > > fatal error: error in backend: unable to write nop sequence of 4 bytes
> > >
> > > Please see BPF CI.
> > >
> > > So far I wasn't able to find a manual workaround :(
> > > Please give it a shot too.
> > >
> > > Or disable the test for this case for now?
> >
> > I noticed this in an earlier version of the series.
> > Will be submitting a fix to LLVM upstream today.
> >
> > Until that's settled, reverting commit 463da422f019 ("MC: make section classification a bit more thorough")
> > in LLVM will fix the issue.
>
> I can confirm the revert fixes the crash.
>
> Let me know what to do (whether to disable the test temporarily and respin, or
> whether the revert can be applied to CI)? And whether I should respin the set
> adding it to DENYLIST.aarch64.
Please respin with some kind of workaround (if possible)
or temp disable just that test.
