From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793716155; b=tUjzn4eparwwPDtObQ+CDaXj8rTFkM8jkMeZHldlIPmw/eBEFtB+V+NMY5pE7g10wgdU MbDwY8RCBeDA2bV2bYyBRKR/Achy9E+bi71V/1RzY3KelGmSc7gR0/ZIQ00Q5Mhxrtubk PZkJJEHIBfxlOoqe5ATYKqijvCXkoR4ylG+PCV/4gOfVZpuqj04zZ27Q7kF4VCJofsde4 lYzbCiMXFOIR6F0w6IcYoyvMf/1Rw++Jj5wE9Jr9+FP1oG4ZXzSRRP3Fx1Me3AVyl6EM3 uRcM8thqwtWV5YVxhPQDzDkX3UkPVoWoj8ExkXZEI70/Cntqsne+c4Q79zCO1GCH8ZQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793716155; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: MIME-Version:Content-Transfer-Encoding; bh=oZHUWqTFzAYc6EeZQBOGUKwe0sk6p3GJrYnYURhZBY8=; b=Zd1rqeWxNRJ6GzD5GIcFolBlRQyBg7I7x1terC8BQ2yY4Nhs6NWdPo8iLn2TmBhwBSRJ ElN5uJQXn8WhiyNTiVrag70JXTqR+iD1t/cVROQigYlfaGz11Kue+zs5oevnjMIzesNaR c/MCukHvDGrhBSBN7Fvi6J8S3L9zQOcoJhyKLxdwynNa5TldPqF+HlvfkO+XwIrfoSSf9 RsG5HJVCC/UsjHpoad/S7w/AlnFTxa02U39RzuGddL1XWC/BENW07LwA4316dKdI1s5vF ssUNKNFePn4zTuBuK49FV8v6F0WT5KeFo3RIL5v9qgdNtLaoBDZvxgrRTBaMs63fiRg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=nMvoDbwN; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D7EE0606A328 for ; Tue, 3 Nov 2026 14:29:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=nMvoDbwN Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3D6BD1F000C1; Tue, 3 Nov 2026 14:29:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793716154; bh=oZHUWqTFzAYc6EeZQBOGUKwe0sk6p3GJrYnYURhZBY8=; h=From:To:Cc:Subject:Date; b=nMvoDbwNiEtRcji2f2h6NDn4nLBheUcVp6L02LSboe2BMJtZo3Q8IC3ADdSrsxyuI ehx9jGurS3vBpELPRduBvafVPyBkJ8H822JCFQ4KfbflluE2s8LMkTlMG12oal68js nmvx+SVTQHS0X/99lKSXAl2R7jeYhBiaSGGSWblIuRYbN0zVb//3yw18EtiLa6kIxJ 02A/Ex3v0KJa/IHwYQ62dEHMf6gP0iR58Kw2h9GUiTi168+irQVL5qh2ePeFVpe+lE 68UuUz6I5sD2TB7Khiuv9bO1AnH2kimWLWHcq5BnJXmx6hY4vOR1DHw1oEdXVqYeby HGo75BA/zdFQA== From: Puranjay Mohan To: bpf@vger.kernel.org Cc: Puranjay Mohan , "Alexei Starovoitov" , "Daniel Borkmann" , "Andrii Nakryiko" , "Martin KaFai Lau" , "Eduard Zingerman" , "Kumar Kartikeya Dwivedi" , "Song Liu" , "Yonghong Song" , Mykyta Yatsenko Subject: [PATCH bpf 0/2] bpf: Shorten pack_mutex critical sections Date: Tue, 3 Nov 2026 06:28:52 -0800 Message-ID: <20261103142856.463063-1-puranjay@kernel.org> X-Mailer: git-send-email 2.53.0 X-Mailing-List: bpf@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Patch 2 moves bpf_arch_text_invalidate() out of pack_mutex, as suggested on v1 [1]. That makes the frees fast enough to hit a deadlock that was already there: the pack_mutex owner frees an empty pack and waits in flush_work() for vmalloc purge work, which cannot run while bpf_prog_free_deferred() items waiting for pack_mutex fill the system_percpu_wq pool. Patch 1 allocates and frees pack memory without pack_mutex. Seen on arm64; x86 and powerpc take the same path. Changes since v1: - Invalidate before taking pack_mutex on all archs, instead of dropping and retaking it on arm64 - New patch 1 for the deadlock [1] https://lore.kernel.org/bpf/20261024031046.625578-1-alexei.starovoitov@gmail.com/ Puranjay Mohan (2): bpf: Don't allocate and free prog pack memory with pack_mutex held bpf: Invalidate freed prog pack memory without holding pack_mutex kernel/bpf/core.c | 58 +++++++++++++++++++++++++++++++---------------- 1 file changed, 39 insertions(+), 19 deletions(-) base-commit: 9abe2c42ecab6c86b54838d2d645ca2e10204606 -- 2.53.0-Meta