| Message ID | 20220223000544.3524440-1-fallentree@fb.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | BPF |
| Headers | show |
| Series | [bpf-next] selftests/bpf: workaround stdout issue in VM launched by vmtest.sh | expand |
On Tue, Feb 22, 2022 at 4:06 PM Yucong Sun <fallentree@fb.com> wrote: > > This apply a workaround to fix stdout issue in `./vmtest.sh` invocations, > but doesn't work on `./vmtest.sh -s` > > Signed-off-by: Yucong Sun <fallentree@fb.com> Could you please provide more information about the issue? > --- > tools/testing/selftests/bpf/vmtest.sh | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/tools/testing/selftests/bpf/vmtest.sh b/tools/testing/selftests/bpf/vmtest.sh > index e0bb04a97e10..a9f943a84ed5 100755 > --- a/tools/testing/selftests/bpf/vmtest.sh > +++ b/tools/testing/selftests/bpf/vmtest.sh > @@ -184,6 +184,10 @@ EOF > fi > > sudo bash -c "echo '#!/bin/bash' > ${init_script}" > + sudo bash -c "cat >>${init_script}" <<EOF > +# Force rebinding stdout/stderr to /dev/ttyS0, to workaround a mysterious issue > +exec 1>/dev/ttyS0 2>/dev/ttyS0 > +EOF > > if [[ "${command}" != "" ]]; then > sudo bash -c "cat >>${init_script}" <<EOF > -- > 2.30.2 >
> Could you please provide more information about the issue?
Still trying to get to the root cause of this issue, I've found that
after https://github.com/kernel-patches/bpf/commit/cb80ddc67152e72f28ff6ea8517acdf875d7381d
, the init process would lose stdout on startup .
ls -lah /proc/1/fd/0 /proc/1/fd/1 /proc/1/fd/2 /proc/1/fd/6 /proc/1/fd/7
lrwx------1 root root 64 Feb 23 17:20 /proc/1/fd/0 -> /dev/null
lrwx------ 1 root root 64 Feb 23 17:20 /proc/1/fd/1 -> /dev/null
lrwx------ 1 root root 64 Feb 23 17:20 /proc/1/fd/2 -> /dev/console
lrwx------ 1 root root 64 Feb 23 17:20 /proc/1/fd/6 -> /dev/console
lrwx------ 1 root root 64 Feb 23 17:20 /proc/1/fd/7 -> /dev/console
and same command on the good commit
ls -lah /proc/1/fd/0 /proc/1/fd/1 /proc/1/fd/2
lrwx------ 1 root root 64 Feb 23 17:23 /proc/1/fd/0 -> /dev/console
lrwx------ 1 root root 64 Feb 23 17:23 /proc/1/fd/1 -> /dev/console
lrwx------ 1 root root 64 Feb 23 17:23 /proc/1/fd/2 -> /dev/console
This patch is merely a workaround until we find and fix the real issue.
Cheers.
diff --git a/tools/testing/selftests/bpf/vmtest.sh b/tools/testing/selftests/bpf/vmtest.sh index e0bb04a97e10..a9f943a84ed5 100755 --- a/tools/testing/selftests/bpf/vmtest.sh +++ b/tools/testing/selftests/bpf/vmtest.sh @@ -184,6 +184,10 @@ EOF fi sudo bash -c "echo '#!/bin/bash' > ${init_script}" + sudo bash -c "cat >>${init_script}" <<EOF +# Force rebinding stdout/stderr to /dev/ttyS0, to workaround a mysterious issue +exec 1>/dev/ttyS0 2>/dev/ttyS0 +EOF if [[ "${command}" != "" ]]; then sudo bash -c "cat >>${init_script}" <<EOF
This apply a workaround to fix stdout issue in `./vmtest.sh` invocations, but doesn't work on `./vmtest.sh -s` Signed-off-by: Yucong Sun <fallentree@fb.com> --- tools/testing/selftests/bpf/vmtest.sh | 4 ++++ 1 file changed, 4 insertions(+)