* [PATCH bpf-next] selftests/bpf: workaround stdout issue in VM launched by vmtest.sh
@ 2022-02-23 0:05 Yucong Sun
2022-02-23 5:18 ` Song Liu
0 siblings, 1 reply; 3+ messages in thread
From: Yucong Sun @ 2022-02-23 0:05 UTC (permalink / raw)
To: bpf; +Cc: andrii, fallentree, sunyucong
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(+)
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
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH bpf-next] selftests/bpf: workaround stdout issue in VM launched by vmtest.sh
2022-02-23 0:05 [PATCH bpf-next] selftests/bpf: workaround stdout issue in VM launched by vmtest.sh Yucong Sun
@ 2022-02-23 5:18 ` Song Liu
2022-02-23 19:02 ` sunyucong
0 siblings, 1 reply; 3+ messages in thread
From: Song Liu @ 2022-02-23 5:18 UTC (permalink / raw)
To: Yucong Sun; +Cc: bpf, Andrii Nakryiko, sunyucong
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
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH bpf-next] selftests/bpf: workaround stdout issue in VM launched by vmtest.sh
2022-02-23 5:18 ` Song Liu
@ 2022-02-23 19:02 ` sunyucong
0 siblings, 0 replies; 3+ messages in thread
From: sunyucong @ 2022-02-23 19:02 UTC (permalink / raw)
To: Song Liu; +Cc: Yucong Sun, bpf, Andrii Nakryiko
> 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.
^ permalink raw reply [flat|nested] 3+ messages in thread
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2022-02-23 0:05 [PATCH bpf-next] selftests/bpf: workaround stdout issue in VM launched by vmtest.sh Yucong Sun
2022-02-23 5:18 ` Song Liu
2022-02-23 19:02 ` sunyucong
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