From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 9BE75C982C7 for ; Fri, 16 Jan 2026 14:40:53 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id F1A476B0092; Fri, 16 Jan 2026 09:40:52 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id EA72D6B0093; Fri, 16 Jan 2026 09:40:52 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DBDAB6B0095; Fri, 16 Jan 2026 09:40:52 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id C89856B0092 for ; Fri, 16 Jan 2026 09:40:52 -0500 (EST) Received: from smtpin28.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 8CF3A1ACA0A for ; Fri, 16 Jan 2026 14:40:52 +0000 (UTC) X-FDA: 84338088744.28.6C2F260 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.223.130]) by imf03.hostedemail.com (Postfix) with ESMTP id 42E3820004 for ; Fri, 16 Jan 2026 14:40:50 +0000 (UTC) Authentication-Results: imf03.hostedemail.com; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b=VIx4ysKc; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b=lUDMhmHY; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b=VIx4ysKc; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b=lUDMhmHY; dmarc=none; spf=pass (imf03.hostedemail.com: domain of vbabka@suse.cz designates 195.135.223.130 as permitted sender) smtp.mailfrom=vbabka@suse.cz ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1768574450; a=rsa-sha256; cv=none; b=FxN4QAR2KuWd5pKNcBLMGPWyJC4yoxho6fC4Bbgdwnds64nqLgzGUGT5ALmcLqpmTOXiGX twhikuA4x4qQNX3LJYiAGmUHjRPlb5FDx5ZXbtPOUq50RUVY/W9WOX3b5QDl6HOxpOchZv xtcEFK8GQQa31oYJx/YgFLlOZDHnV3g= ARC-Authentication-Results: i=1; imf03.hostedemail.com; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b=VIx4ysKc; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b=lUDMhmHY; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b=VIx4ysKc; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b=lUDMhmHY; dmarc=none; spf=pass (imf03.hostedemail.com: domain of vbabka@suse.cz designates 195.135.223.130 as permitted sender) smtp.mailfrom=vbabka@suse.cz ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1768574450; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=N3DPRc87aFtnpwc8583i8li1YmCTDsn4GBRi/xoPavM=; b=Oq4FBDCYKIg8YtLIgtQi6HDdth8a+2C+ZAg/qmSnHtWgelCJJihZO2/0atyM4ky6rhPSsd WLbLspyuDh8EA/WJOrE/AEpcwx8U+emfkC4YkPpawI+uFKCk0pZJvvcge6xiXaElrYhDTM 5ptbN45TZN1rAfg9zccjw+bmNh/Y48E= Received: from imap1.dmz-prg2.suse.org (imap1.dmz-prg2.suse.org [IPv6:2a07:de40:b281:104:10:150:64:97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id AF381337C8; Fri, 16 Jan 2026 14:40:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1768574436; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=N3DPRc87aFtnpwc8583i8li1YmCTDsn4GBRi/xoPavM=; b=VIx4ysKcVd45gYQ05wOQxYUCWqZWv0RkE8KFAngIZWuPyVPw/A3nlnjsZJ3Pu9JOmeYdzO az79Ytn2bavsmsW42oA7p5lHvewH6Ys3FmoRoP4OlXN2mS3dnOQlq4HJLsewwYypRi9OsG P2FSirPQ7oaRxHt8wVMxtCvzOCoST2o= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1768574436; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=N3DPRc87aFtnpwc8583i8li1YmCTDsn4GBRi/xoPavM=; b=lUDMhmHYsrl4K7lNpMBUcqhJq2GaLk9ZOMCidLB2S6PYZPd5WWdyL0SImiMebL5HArMOph /D8S4kbBtC4qu2AA== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1768574436; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=N3DPRc87aFtnpwc8583i8li1YmCTDsn4GBRi/xoPavM=; b=VIx4ysKcVd45gYQ05wOQxYUCWqZWv0RkE8KFAngIZWuPyVPw/A3nlnjsZJ3Pu9JOmeYdzO az79Ytn2bavsmsW42oA7p5lHvewH6Ys3FmoRoP4OlXN2mS3dnOQlq4HJLsewwYypRi9OsG P2FSirPQ7oaRxHt8wVMxtCvzOCoST2o= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1768574436; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=N3DPRc87aFtnpwc8583i8li1YmCTDsn4GBRi/xoPavM=; b=lUDMhmHYsrl4K7lNpMBUcqhJq2GaLk9ZOMCidLB2S6PYZPd5WWdyL0SImiMebL5HArMOph /D8S4kbBtC4qu2AA== Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id 8A1043EA65; Fri, 16 Jan 2026 14:40:36 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id uMFpIeRNamnydgAAD6G6ig (envelope-from ); Fri, 16 Jan 2026 14:40:36 +0000 From: Vlastimil Babka Date: Fri, 16 Jan 2026 15:40:21 +0100 Subject: [PATCH v3 01/21] mm/slab: add rcu_barrier() to kvfree_rcu_barrier_on_cache() MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260116-sheaves-for-all-v3-1-5595cb000772@suse.cz> References: <20260116-sheaves-for-all-v3-0-5595cb000772@suse.cz> In-Reply-To: <20260116-sheaves-for-all-v3-0-5595cb000772@suse.cz> To: Harry Yoo , Petr Tesarik , Christoph Lameter , David Rientjes , Roman Gushchin Cc: Hao Li , Andrew Morton , Uladzislau Rezki , "Liam R. Howlett" , Suren Baghdasaryan , Sebastian Andrzej Siewior , Alexei Starovoitov , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-rt-devel@lists.linux.dev, bpf@vger.kernel.org, kasan-dev@googlegroups.com, Vlastimil Babka , kernel test robot , stable@vger.kernel.org X-Mailer: b4 0.14.3 X-Rspamd-Action: no action X-Rspamd-Queue-Id: 42E3820004 X-Rspamd-Server: rspam06 X-Stat-Signature: e6z8yhkanuznzrcw5kdcbx743qji7o6p X-Rspam-User: X-HE-Tag: 1768574450-770789 X-HE-Meta: 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 ytf0UwZq zyG2VQDSz/h0ufg1N4BWhfQaEGxn6bg+BZbiyMCf30/BGvG0MNVCLKSz2tTbMVqb0TZUKXeJ6yaGbFOhfzhx0T3P3qUgvCvVpsW936uT0Fg0C3iFW98wePWJgKnLw7tHhl2q77XkYFtAsjiP6GbiuaZHwYfsYQBUA/2iJuLq2JsnHRan5UiqEpHQ0ugd+yb3RnfjuBdkxa9JvY/eyKwC3yjQT4K0bYUikgFoL0GMFJF5GvdCSOnc0c5ZYhk5kHdD/mkD2Ji4+tFmJ89N//f4VlwWEsyHUsDWourjR4Ly4pygno/DAvbzLbsGHN7W1iEjfRlGag8GaUaHczKukeHiyOTh7L8+IICteyY/qgONzKsMksb96teWpz6K1sulXug2mz1yG2UNimmgukgA= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: After we submit the rcu_free sheaves to call_rcu() we need to make sure the rcu callbacks complete. kvfree_rcu_barrier() does that via flush_all_rcu_sheaves() but kvfree_rcu_barrier_on_cache() doesn't. Fix that. This currently causes no issues because the caches with sheaves we have are never destroyed. The problem flagged by kernel test robot was reported for a patch that enables sheaves for (almost) all caches, and occurred only with CONFIG_KASAN. Harry Yoo found the root cause [1]: It turns out the object freed by sheaf_flush_unused() was in KASAN percpu quarantine list (confirmed by dumping the list) by the time __kmem_cache_shutdown() returns an error. Quarantined objects are supposed to be flushed by kasan_cache_shutdown(), but things go wrong if the rcu callback (rcu_free_sheaf_nobarn()) is processed after kasan_cache_shutdown() finishes. That's why rcu_barrier() in __kmem_cache_shutdown() didn't help, because it's called after kasan_cache_shutdown(). Calling rcu_barrier() in kvfree_rcu_barrier_on_cache() guarantees that it'll be added to the quarantine list before kasan_cache_shutdown() is called. So it's a valid fix! [1] https://lore.kernel.org/all/aWd6f3jERlrB5yeF@hyeyoo/ Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-lkp/202601121442.c530bed3-lkp@intel.com Fixes: 0f35040de593 ("mm/slab: introduce kvfree_rcu_barrier_on_cache() for cache destruction") Cc: stable@vger.kernel.org Reviewed-by: Harry Yoo Tested-by: Harry Yoo Reviewed-by: Suren Baghdasaryan Signed-off-by: Vlastimil Babka --- mm/slab_common.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/mm/slab_common.c b/mm/slab_common.c index eed7ea556cb1..ee994ec7f251 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -2133,8 +2133,11 @@ EXPORT_SYMBOL_GPL(kvfree_rcu_barrier); */ void kvfree_rcu_barrier_on_cache(struct kmem_cache *s) { - if (s->cpu_sheaves) + if (s->cpu_sheaves) { flush_rcu_sheaves_on_cache(s); + rcu_barrier(); + } + /* * TODO: Introduce a version of __kvfree_rcu_barrier() that works * on a specific slab cache. -- 2.52.0