From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=209.85.210.197 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793809743; b=nqW94TKZ4KnOCR/ZvSiv3IjS/Y6Hb7j7w6zQKR3d6wcd+wjl6DUtvQJkYuUWqXzSeoFd jQFir1bTCCGMyYTiBc+1zu37lVnGl9wfPkfxkoZP7S91xJHAzQIGKRxiZZjOHl7UmcB1i hPI463j/sg21xdoPCaYTaQ8sFimlMUOyiPWXp+aCPpTDlf8XtTo32pWfU6XrgvOrh90fi L6CceRdo/jeg/jvDSYWlmloMMd34aQE/fbhvth/U+m/wDDxsBAUHcJwF4ZHFzJaYP4ofP NLHV42CD+XE02KTh2i9Wq6T5bwHCz1JQaWPZBT+OT+YXSBwVcF/YY0aoZ9z1p8p0CFg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793809743; h=DMARC-Filter:Received:DKIM-Signature:X-Google-DKIM-Signature: X-Forwarded-Encrypted:X-Gm-Message-State:X-Received:Date:Mime-Version: X-Mailer:Message-ID:Subject:From:To:Cc:Content-Type; bh=aMXCCZD/Ct0GmViTFWPgT1+QbEU503C2HJaGHUQ7IDQ=; b=grsvDmMmdzNk77jcNbMeesIaHueGB+VJy7W/T4feUuRX+TeBArzxW2/NGgzJ+VYWqXzw nU4zhgaVSMZWMjXIhHplgxBmJh03S94g4MwAjDwFzmRgXlar4dNf8hBYuN7p4rlJtcnqJ V77DZz0wBJKEWhsbLUEPoJFQ86UNpjP6Qf+tm9yihk40b3RDxm+Fu1jf5sxfjWDQvyGAR P+dfTAwBX9F/49E994HG7xyGdtwTkpegt6EJYv1W/OlHQ95e19pelIdtsSeBwWcZbkOxj AyZhhDi05divmwmnv27+p26TeEZLaj2zpCNkstCCBFaq6xJQcQG4t3zRo1Ug+g6g3ww== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=google.com; spf=pass smtp.mailfrom=flex--kuniyu.bounces.google.com; dkim=pass header.d=google.com header.i=@google.com header.a=rsa-sha256 header.s=20260707 header.b=jQy3xh7A; arc=none smtp.remote-ip=209.85.210.197 Received: from mail-pf1-f197.google.com (mail-pf1-f197.google.com [209.85.210.197]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B05D2606A31B for ; Wed, 4 Nov 2026 16:29:02 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org B05D2606A31B Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--kuniyu.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=google.com header.i=@google.com header.a=rsa-sha256 header.s=20260707 header.b=jQy3xh7A Received: by mail-pf1-f197.google.com with SMTP id d2e1a72fcca58-8a0592d4539so1358115b3a.3 for ; Wed, 04 Nov 2026 08:29:02 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20260707; t=1793809741; x=1794414541; darn=vger.kernel.org; h=content-type:cc:to:from:subject:message-id:mime-version:date:from :to:cc:subject:date:message-id:reply-to:content-type; bh=aMXCCZD/Ct0GmViTFWPgT1+QbEU503C2HJaGHUQ7IDQ=; b=jQy3xh7AM/EpJ8ATzYgmP7dFHvpCNxiEcvtsoX+LA4ZgGtE1DLTwsP8YI0/NT1Bjr3 /ZBNo66ol0FL/xV9BqtXLoMGuZ9iQglymDGHkRXyojgzgVSiK8Ct9yB03L+hB4WXY8ij y2z7hNJ+tRaKDaCj9TltXJI3Zrim46uy/MNzBtQ0TiBlaNxejSHV7T03dNwRX1MNmlNh HF8WbCU1icygo4kLXZ3JjnwDFgDcq0M1/hJLDeZ9BTYpqOr5NMB0+pNjpa2nnJR8HGKr sqO1z/PDUQdD2q13Qn2WxRGr0w+VlPImMSY3L0sQpHOiQxj6AjS3dFJeHzacP1AD860F mnAQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1793809741; x=1794414541; h=content-type:cc:to:from:subject:message-id:mime-version:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=aMXCCZD/Ct0GmViTFWPgT1+QbEU503C2HJaGHUQ7IDQ=; b=tiGuH52OJ/9zvrK+rLyD749Alarfnb/9ohDuRJZOAmbhmz0wzrDqn69IBEjdGgLnKu Quwc2SlpBtao5JPhAn03rCzzFJl8/Y54tBEoP+Oq93fTeqsXHvq1DxMrTWfJHW+emKKJ OPhf9ZxYUAmomYzTgjW/sYuHgJZn15Tp9KH01VYOlgAjfjs5bhLxMLGH8hv+lOYCDLZ3 y+T1jMPO3UJSRbzDnw8UJlGgjtMADykmhZiWMtJ+AC1cOr5x4KqCx7Nv/yGFvUOyfsGA Pf+T/AGvcnMr/qucJ1G7FZvbv6zk9Zhrbphxx9Hof3hY57l1NsqZcQoNfcSsWO+G5jLM VLFA== X-Forwarded-Encrypted: i=1; AKwUvBxR7oW7aIPedNtp0m+xZTdX6vOx7i16V/8n0rbjcURKIOnKWxaraoGcob4Yv6h1wwe50aH6PyE=@vger.kernel.org X-Gm-Message-State: APuU4Z+D6vkCSHUde6/uMi6jV02l+XO39/DQn5LmIyZdLm+SHoNt7SZa pvdKgNL1wGKLKGuY12PC9pSsjaOHL8BPj+Wz3R0yQf5WMg0OWkB+XxWxpx3XnOtyikWK08iGUVY FLOwDlA== X-Received: from pgdo19-n2.prod.google.com ([2002:a05:6a02:6213:20b0:cd6:db2:b293]) (user=kuniyu job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a20:6a0b:b0:3e0:e242:5ff with SMTP id adf61e73a8af0-3e928a29f0bmr15815926637.56.1793809741292; Wed, 04 Nov 2026 08:29:01 -0800 (PST) Date: Wed, 4 Nov 2026 16:27:56 +0000 X-Mailing-List: netdev@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list Mime-Version: 1.0 X-Mailer: git-send-email 2.56.0.385.gac671c819a-goog Message-ID: <20261104162858.991930-1-kuniyu@google.com> Subject: [PATCH v1 net] af_unix: Remove gc_in_progress check in unix_peek_fpl(). From: Kuniyuki Iwashima To: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni Cc: Simon Horman , Kuniyuki Iwashima , Kuniyuki Iwashima , netdev@vger.kernel.org, Qihang Tang Content-Type: text/plain; charset="UTF-8" unix_vertex_dead() and unix_peek_fpl() are synchronised with unix_peek_seq to prevent GC from purging a live socket's recvq. unix_peek_fpl() skips the synchronisation if gc_in_progress is false. However, on weakly ordered arch, GC might have already started working while the write to gc_in_progress is buffered. This does not occur on x86. This is an unlikely path that happens only when AF_UNIX fd is peeked so not worth complicating. Instead of adding memory barriers in unix_gc() and unix_peek_fpl(), let's simply remove the broken short-circuit. Fixes: e5b31d988a41 ("af_unix: Give up GC if MSG_PEEK intervened.") Reported-by: Qihang Tang Signed-off-by: Kuniyuki Iwashima --- The reporter reproduced it on arm64 QEMU. --- net/unix/garbage.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/net/unix/garbage.c b/net/unix/garbage.c index a0b515354e8b..fbeabfb0db34 100644 --- a/net/unix/garbage.c +++ b/net/unix/garbage.c @@ -329,9 +329,6 @@ void unix_peek_fpl(struct scm_fp_list *fpl) if (!fpl || !fpl->count_unix) return; - if (!READ_ONCE(gc_in_progress)) - return; - /* Invalidate the final refcnt check in unix_vertex_dead(). */ spin_lock(&unix_peek_lock); raw_write_seqcount_barrier(&unix_peek_seq); -- 2.56.0.385.gac671c819a-goog