From patchwork Sun Sep 29 13:27:53 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Leon Hwang X-Patchwork-Id: 13815089 Received: from out-178.mta1.migadu.com (out-178.mta1.migadu.com [95.215.58.178]) (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 7BFDDAD24 for ; Sun, 29 Sep 2024 13:28:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.178 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727616500; cv=none; b=KaxNzD+K/D853HNPk1FYFL9zFAIXh616UvVHqJnMKlmfX1dfsIvPVU0t2k6elNJilL1kZcs0lax1RC23KPGnMTuWn3TAqswnSWcqlNo0a5hfcslGydAiLkFOeW9qwmEHLiXTAZWEflhTCSNHIRLe4u8kW16941ZgmLOG02ZNoNY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727616500; c=relaxed/simple; bh=wRuryGddViZoj0M5mHxd0KIwl3Pi1ftLyms2NYZhmZw=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=MwtfrvAcxBj/Ozl4NlxQOBwuzpiGiMk1BIDugp/9pap8tkcugvjJJbOjrl2PlCY0JWv/SvHezqBzhoYtx/I73IlCVpva5DIarc03l4KUxI5DDbytx3zS9fwijUqwXn1B0UVXZyl3ZFdxvP6uVOP9QLfrSfsN+fkxA18gHg1AZ5s= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=WFPwOeC2; arc=none smtp.client-ip=95.215.58.178 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="WFPwOeC2" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1727616496; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=MP7egvaOL+u+UnlpYIG2XyDmYiYlz0H6oPBEyjothb4=; b=WFPwOeC2oVrKf7SR8JotJ68XBm5RVrA8Z4hw/ptfiNWqEXOd5tDXqsPNPbs3gw2Nb85ACp RufRMxgsVftO7kWsk2Ha2GNMihBIKhoRgUO/KYU6Mfr4CZPp+y3WwTOlZBeVFa/fYq+vNH bP9RO7t5k4yoqScSiYQV0IdfIK7jGWY= From: Leon Hwang To: bpf@vger.kernel.org Cc: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, toke@redhat.com, martin.lau@kernel.org, yonghong.song@linux.dev, puranjay@kernel.org, xukuohai@huaweicloud.com, eddyz87@gmail.com, iii@linux.ibm.com, leon.hwang@linux.dev, kernel-patches-bot@fb.com Subject: [PATCH bpf-next v4 0/4] bpf: Fix tailcall infinite loop caused by freplace Date: Sun, 29 Sep 2024 21:27:53 +0800 Message-ID: <20240929132757.79826-1-leon.hwang@linux.dev> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT X-Patchwork-Delegate: bpf@iogearbox.net Previously, I fixed a tailcall infinite loop issue caused by trampoline[0]. At this time, I fix a tailcall infinite loop issue caused by tailcall and freplace combination by preventing updating extended prog to prog_array map and preventing extending tail callee prog with freplace: 1. If a prog or its subprog has been extended by freplace prog, the prog can not be updated to prog_array map. 2. If a prog has been updated to prog_array map, it or its subprog can not be extended by freplace prog. v3 -> v4: * Address comments from Eduard: * Rename 'tail_callee_cnt' to 'prog_array_member_cnt'. * Add comment to 'prog_array_member_cnt'. * Use a mutex to protect 'is_extended' and 'prog_array_member_cnt'. v2 -> v3: * Address comments from Alexei: * Stop hacking JIT. * Prevent the specific use case at attach/update time. v1 -> v2: * Address comment from Eduard: * Explain why nop5 and xor/nop3 are swapped at prologue. * Address comment from Alexei: * Disallow attaching tail_call_reachable freplace prog to not-tail_call_reachable target in verifier. * Update "bpf, arm64: Fix tailcall infinite loop caused by freplace" with latest arm64 JIT code. Links: [0] https://lore.kernel.org/bpf/20230912150442.2009-1-hffilwlqm@gmail.com/ Leon Hwang (4): bpf: Prevent updating extended prog to prog_array map bpf: Prevent extending tail callee prog with freplace prog selftests/bpf: Add a test case to confirm a tailcall infinite loop issue has been prevented selftests/bpf: Add cases to test tailcall in freplace include/linux/bpf.h | 3 + kernel/bpf/arraymap.c | 30 ++- kernel/bpf/core.c | 1 + kernel/bpf/syscall.c | 53 ++++- .../selftests/bpf/prog_tests/tailcalls.c | 196 +++++++++++++++++- .../tailcall_bpf2bpf_hierarchy_freplace.c | 30 +++ .../testing/selftests/bpf/progs/tc_bpf2bpf.c | 37 +++- 7 files changed, 335 insertions(+), 15 deletions(-) create mode 100644 tools/testing/selftests/bpf/progs/tailcall_bpf2bpf_hierarchy_freplace.c