From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 34F673B1016 for ; Sat, 11 Jul 2026 10:54:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783767244; cv=none; b=cgISocrCsWFZQ15ffjtpMgU6HbGVyU2uYaxNrnsAcePXXZwGVkxaYyQE7IrBb/P2soMecWEowfnV+4sz3L0vmx8bayWoRfxi1WfjwEpy6adaUumvRRnd/m/hzSJuCk2qEADXOlzO/3zuNP/QXd4/BU9CSNMvNuUaBLPP1XHJR7w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783767244; c=relaxed/simple; bh=EMygczQZ0IM/8++q6I6ih+jWeCYGOvtfOTomUlFgKz0=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=pZsoZ82FmG//nNjcmWtktL9nUZHKt4S4jBd6tdq6YklY/LgQPsRouJFub94JknxFKFlUzsUE40e7flmH+OZuV7PQDEa1N4EdCuyVMllAwwWi1tyUrg0WB8RooscrT27LLs6SWx5a9M0Ir/T2n1CJXfPBFHb8VC+h2Y4u+nzGyhM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=RoPmXzFE; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="RoPmXzFE" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 84DF81F000E9; Sat, 11 Jul 2026 10:54:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1783767241; bh=9itvaQYr+UFCMUuw4yttyefsu1AzzHFvXzCPx5XRXL8=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=RoPmXzFEUOVCQkKQohbqRXcIa5rn3IzKXKmKnew8pyaaNAQtJblC1s8DhLg5YuyA9 Wv4PdxPW6JymDQ/iBDGwfs+oUUPxC3w7ofG2aRH+Wmr7HLbiomOQ2vl8/INatrSrqK GJJdY0rtvb+hCQiU/JBluLsGVq2hi8NctnOqXJ9dcEqhekAkv3eT/fiqt78T6bkjiy +ut0ZGz84EhI6stOfqzCbBtphubB1g/SSzorc679iDipkESLpccKQdcxRCN+YNAV61 u7FNnAOAoy2AxtEWe24rbfMlVjlhvY4Mf3HFOapQfkebNGfvRqmQDRt26JHHwpE9gG AWs8x0ozW1Fgg== From: sashiko-bot@kernel.org Subject: Re: [PATCH bpf-next 2/2] selftests/bpf: Add testcases for callback with tailcall Reply-To: sashiko-reviews@lists.linux.dev To: "Pu Lehui" Cc: bpf@vger.kernel.org In-Reply-To: <20260711104727.4023420-3-pulehui@huaweicloud.com> References: <20260711104727.4023420-1-pulehui@huaweicloud.com> <20260711104727.4023420-3-pulehui@huaweicloud.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Sat, 11 Jul 2026 10:54:01 +0000 Message-Id: <20260711105401.84DF81F000E9@smtp.kernel.org> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Thank you for your contribution! Sashiko AI review found 1 potential issue(= s) to consider: - [High] The test `tailcall_direct_callback` intentionally expects a verifi= er bug message (`"callback unexpected regs 1"`), which triggers a kernel `W= ARN_ONCE`. -- --- Patch [2]: [PATCH bpf-next 2/2] selftests/bpf: Add testcases for callba= ck with tailcall --- commit 037342732803eb60c98636ac87d004705531bc5d Author: Pu Lehui selftests/bpf: Add testcases for callback with tailcall This patch adds three testcases for BPF callbacks interacting with tail cal= ls. It tests scenarios where a callback directly invokes a tail call, or where subprograms invoked by the callback issue the tail call. > diff --git a/tools/testing/selftests/bpf/progs/tailcall_callback.c b/tool= s/testing/selftests/bpf/progs/tailcall_callback.c > new file mode 100644 > index 0000000000000..504d8e7a69969 > --- /dev/null > +++ b/tools/testing/selftests/bpf/progs/tailcall_callback.c [ ... ] > +/* callback involving tail call directly is rejected */ > +SEC("tc") > +__failure __msg("callback unexpected regs 1") > +int tailcall_direct_callback(struct __sk_buff *skb) > +{ [Severity: High] Does expecting this specific failure message codify a kernel warning as a passing testcase? The message "callback unexpected regs 1" is emitted by verifier_bug() in kernel/bpf/backtrack.c during precision backtracking, which intentionally triggers a kernel WARN_ONCE. On systems configured with panic_on_warn=3D1, such as syzbot or standard CI environments, wouldn't loading this test cause a kernel panic? If the verifier hits an internal state corruption (tracking r0 back into a faked exit) and triggers verifier_bug() before it can gracefully reject the program, does this indicate that the underlying issue with callbacks and ta= il calls isn't fully fixed by the series? > + clobber_regs_stack(); > + > + bpf_loop(1, callback_loop_1, &skb, 0); > + return 0; > +} --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20260711104727.4023= 420-1-pulehui@huaweicloud.com?part=3D2