From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=209.85.218.53 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793976207; b=Zp6IOwLPwECkZxASi+kG0+qHN5ZtJDwXt79WiWUyAMPmBtlEqEI0ZjjcuFLNV2KKljM7 XIc1swzID6poEWO+mjVR9eEYv+5Mk1BEGdaQ30jgvWc7P9BwDx7CTg0Fadnp8kupSyzPk W6ZBSK6sepfKn96RVc8ukM0noiKSb7tB8ZXzRIsUTY/w0tiqOLFBX9AcCd5Z5ii8xm3T3 hNKHEz+DJKKx6FnYSgwjKC+8AnyI7bL2vV8W6Nh4a2dKNx1If9TDT8O7IWl0dYWlN2rym JzRxDqjlPkbg8Y45nOuNwVKoZ9Fovq9vNi4FH5AoVmHk+u62GKsMQ7n1zsEv3I8G3EA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793976207; h=DMARC-Filter:Received:DKIM-Signature:X-Google-DKIM-Signature: X-Forwarded-Encrypted:X-Gm-Message-State:X-Gm-Gg:X-Received:Received: From:X-Google-Original-From:Date:To:Cc:Subject:Message-ID:References: MIME-Version:Content-Type:Content-Disposition:In-Reply-To; bh=1coO61O9o20KGfWhe+U/6TV0ZY/FeV096v+PDZIBmoM=; b=iMWr1BEIaL8p1zQDyGxPTi5x19KUleN8SCG/JIfUu7+P7fg8FC0Y/D3NPt4yD4GY7pLp Pvc6x0NjT/k3HXngwWqNRq0AJpqh2TtKsOlolx6Iiq+Ekz1h8yOom8XQAP7PkTH4KWtCk G9TnN9G25BujMfuPYXm3kWv7KmXyXKsUZK00soKhp5CwN7NPy7SksXjlxFBriG0HYNzLx QlBFQHyE8fJvSHSM2hpUttDyaqR6Wif+zYJC1v3GJgXtRgmFanEMsyliAbWQf+xhTTeAV Eyry73GcjCE0D63xl9RemZcwSt3JUifcnR8488798pIDn3EnibuShK3d/hdC5pKDlcA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20260707 header.b=dQ8Kjz3P; arc=none smtp.remote-ip=209.85.218.53 Received: from mail-ej1-f53.google.com (mail-ej1-f53.google.com [209.85.218.53]) (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 86D7D6082BC2 for ; Fri, 6 Nov 2026 14:43:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 86D7D6082BC2 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20260707 header.b=dQ8Kjz3P Received: by mail-ej1-f53.google.com with SMTP id a640c23a62f3a-c434376dbebso146349666b.1 for ; Fri, 06 Nov 2026 06:43:27 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20260707; t=1793976206; x=1794581006; darn=vger.kernel.org; h=in-reply-to:content-disposition:content-type:mime-version :references:message-id:subject:cc:to:date:from:from:to:cc:subject :date:message-id:reply-to:content-type; bh=1coO61O9o20KGfWhe+U/6TV0ZY/FeV096v+PDZIBmoM=; b=dQ8Kjz3Pm/40Y6QK+wnykiNHDgz7dKP607sj6/+hqieIq1ZmyilklclOYXjWaBJyZQ wigV9r8VouxbEKE9QgPdw1VpSrB3xLnotHYSSNbzuz878AnRPuvoVHRTNcqgEq7hLDnq EBy4H5xYRegGJoTvMOlxOYRVq93ULaPKtOQBRtm4a5TxD5b5qxrLBPFkjRnIHAg/fRo8 SPdaU35rkr0LfaG3/AS4/PMkK2BSbubxBavooY3Ygux0TcvwzrklGLkuYTCBblRoq/9Q wGBWvVpbu/YmDkyrFWrcQ9+Xr/vMo02AxG7ipmZa006A9g2kUtdIwncG4kcQ9DAOguTO Q3Kw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1793976206; x=1794581006; h=in-reply-to:content-disposition:content-type:mime-version :references:message-id:subject:cc:to:date:from:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=1coO61O9o20KGfWhe+U/6TV0ZY/FeV096v+PDZIBmoM=; b=VdWt3ksxDg/GJX6ARQ4InP6RJapxCBfZitohhLVnTVWqMUMk6yruS6lK6ZErmS3ygi dJ1HfbcK9HP9WpusvRbbsdkdTJ9aRkFwJ1WdazLnj3LHFnNS1RFUFPegZcio7x4MGNmg XllL96nTtd2imYl5qXvtRneMpl41KB0+tea8X2xNUwFjanzo5arCwd9wW61KdZqv8bAO RHS3x1n3fvsPPbFz7+9+J9q9RQVxiSeQYEMUro++ga05sbZNhiWZhqLfGDKIo4qPxU1i UryCyQ+aGYXw9GvRRgSLfjSgze20zaoIhk2wnsMzsurjxadlpbi4GgBQdQCMY3oy0rFz PT8Q== X-Forwarded-Encrypted: i=1; AKwUvBzM3NQoYfG+IoMEllx26F7bmio9WLZFZzSemLxggdcIn7Lg2sTFTf+j3+g6h0wSc6BJYhJkJIo2R15H2mU=@vger.kernel.org X-Gm-Message-State: APuU4Z8muo0L0v4XZwa7p8DUfWSWL47PjiDWzJ880EEfFWTIASjoN+Be uBXoaFfFlg7nt3dOynNmhutiloItz5ac/WPyysjObZ5KPPK7eLKD76pO X-Gm-Gg: AYBFou0u2K2p0fUB6Vad4xRpw3KWq1gYsDwGvYVU3jqvEDBQyU9NViEn5yZWPQiu+Zl GxCjYtL9rOVpDdFuRIfVwvdpVwSc+gxZj4WTGLk7bq2qh1LDYHdayBhk4LEdsa+DsajLYLNWy5K 0CDocQ/+yVUZGe6mlGQjIM3OSO/0sFl77tFHX0tIMWzPq3Wu3dKFQOS9s99rE0w1xXIxy3JozMY E5yd4E6uuYFtyd6Ow9iYRmKWUOig98pPlZJU6GrioqUyQ8P2toMYufuiUJFNsCn5N2msAEPNrTJ GGT0oM7051x5IudVlwmEA8x5+3zujMd3QqKQ1zuHsLK4PizVSpj5e3hNk0cGJ0V9swsUHVQOqEp FQppY9GInD5L1ubta7Wo0CtmyIla896JhljiQeJf4pURMb5jtpWXZ0in6qfS3/EVy0WwHTMmx5i Z50d9xdXdNUB/jl7ucGAnWxRjFLSHN2Vg5xGyu/ipG4zZ8ZMakn0Btis9Tw1Is5qjO+q985Wc2U c4xyw3PApWUXTP+Z2+19DcjEXPbmvvaEnCjDMSZxBpL+PcljtC63W7kjq5rINFJHRoH X-Received: by 2002:a17:907:fdcb:b0:c2e:616b:6763 with SMTP id a640c23a62f3a-c4d3525a3f4mr249438666b.3.1793976205728; Fri, 06 Nov 2026 06:43:25 -0800 (PST) Received: from milan ([2001:9b1:d5a0:a500::24b]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-c4d35631eb2sm86304166b.27.2026.11.06.06.43.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 06 Nov 2026 06:43:24 -0800 (PST) From: Uladzislau Rezki X-Google-Original-From: Uladzislau Rezki Date: Fri, 6 Nov 2026 15:43:21 +0100 To: Linus Torvalds Cc: Uladzislau Rezki , Herbert Xu , "Liam R. Howlett (Google)" , Davidlohr Bueso , Michal Hocko , Baoquan He , Alexander Potapenko , Andrey Ryabinin , Marco Elver , Michal Hocko , Linux Crypto Mailing List , Andrew Morton , Thomas Graf , linux-mm@kvack.org, linux-kernel@vger.kernel.org, maple-tree@lists.infradead.org, Lorenzo Stoakes , Chris Mason , Alice Ryhl , Andrew Ballance , stable@vger.kernel.org, "David Hildenbrand (Arm)" Subject: Re: [PATCH 4/4] rhashtable: fix vmalloc() deadlock in atomic rehash Message-ID: References: X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Thu, Nov 05, 2026 at 01:02:35PM -0800, Linus Torvalds wrote: > On Thu, 5 Nov 2026 at 10:44, Uladzislau Rezki wrote: > > > > @@ -1025,7 +1025,13 @@ void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source, > > } > > } > > } else { > > - spin_lock(&br->hash_lock); > > + if (in_serving_softirq()) { > > + if (!spin_trylock(&br->hash_lock)) > > I don't think that in_serving_softirq() makes any sense. > > If I read this code correctly - and it's possible I didn't - this is > always called under local_bh_disable(). > > And local_bh_disable() will have increased the preempt-count exactly > so that it looks like it's in_serving_softirq(). > Sorry, probably i am missing something here. My understanding is that local_bh_disable() adds SOFTIRQ_DISABLE_OFFSET and in_serving_softirq() checks another SOFTIRQ_OFFSET bit. -- Uladzislau Rezki