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.
