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=1794061157; b=cS0ae3xrzNH3d4Epw+oxhqC55HGSNkK3KR+MlBZUWToVpFyNEMPm8aG7K1H0PfPnTQYO n+3O/ZxVmQ15XU32HdP/WYybolC1oRhlsDlVwNUk70IcdT0N9ArS2gppW0xGTHzCT1Fx3 IZnMzhYtKvUFi9odnH5+/LcLcKPncHG1RHpbRAf5bqb0rFGALkK3Rpeyh9ujnBDIutsbB aPaKQ395EvdCp4BkFfH61IL1JAtXyP6Vkblbrr7ei3doHFGOU/MW+yI71q+c0/ikklNPG oU2gS/3Z/iAiuBROEeiImbo1bcxOQqfsLKijZnH0e+1nX2Q43T0x4EF8S6oTGOr6SKw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794061157; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=Or8Zak/BmurYQXHbPG79GmyTXHsmKMTHQrpDls/nJe4=; b=ESb1Mt8DkgvKf9Q53LK2+YrcaR9zJSL7l5FfpMRipsayvPKXAnEhLWZZryUf/wxJFlfm n92w7zIz5nCuDxPJnnJnrewVvCPU9d8kkFZjev05g50sozoCi5QfswdneAwxuzvozoHYU gLUd1fgRtu41gg9bCVA5FO8kkq3wtyIwwK5MIkpvyhPqeMA8V/BD0D51rlknsnQjXwfXE 0cfu+2m9/zZyXiTrtgMrmuY+a5Qa+T6o1AVU/nh75uewwMDYdm7xyLAM0jW/3jP+V+97S WsjAbfZhx8H+qUzV4kPKgZblGXXL56eZMitt9hIldEYExPc3MaMFJf+nAnCwO5Cce/A== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b="XWOhwEC/"; 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 38637606D805; Sat, 7 Nov 2026 14:19:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=XWOhwEC/ Received: by smtp.kernel.org (Postfix) with ESMTPSA id D13A11F0089F; Sat, 7 Nov 2026 14:19:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794061157; bh=Or8Zak/BmurYQXHbPG79GmyTXHsmKMTHQrpDls/nJe4=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=XWOhwEC/c33bLW62r5UhF2p91mCHjhfADDhQtLXeYWGVHGJ1Lwuh0Y4APmXHQ5RkP i9CiDHHRzTeVKKbZ6K2AqpxBK59vpxQayb/2nN6kW3rb9EdtEZI7dmhHFy1OeYa+tZ 7Y4whOFd5/H+5UPhXrTGHx5lKcQ9IGM2dtbPyeO0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Sebastian Andrzej Siewior , "Peter Zijlstra (Intel)" , Petr Pavlu , Sasha Levin Subject: [PATCH 6.12 0464/1536] module: Use RCU in find_kallsyms_symbol(). Date: Sat, 7 Nov 2026 08:41:20 -0500 Message-ID: <20261107135010.549697570@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261107134957.653319350@linuxfoundation.org> References: <20261107134957.653319350@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: stable@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 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sebastian Andrzej Siewior [ Upstream commit f01369239293e4900af7be673e0fd26fe54f85e1 ] The modules list and module::kallsyms can be accessed under RCU assumption. Use rcu_dereference() to reference the kallsyms pointer in find_kallsyms_symbol(). Use a RCU section instead of preempt_disable in callers of find_kallsyms_symbol(). Keep the preempt-disable in module_address_lookup() due to __module_address(). Signed-off-by: Sebastian Andrzej Siewior Acked-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20250108090457.512198-5-bigeasy@linutronix.de Signed-off-by: Petr Pavlu Stable-dep-of: 0e9f090a4e9b ("module/kallsyms: fix nextval for data symbol lookup") Signed-off-by: Sasha Levin --- kernel/module/kallsyms.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/kernel/module/kallsyms.c b/kernel/module/kallsyms.c index 30d0798f114f1..18931db1369da 100644 --- a/kernel/module/kallsyms.c +++ b/kernel/module/kallsyms.c @@ -260,7 +260,7 @@ static const char *find_kallsyms_symbol(struct module *mod, { unsigned int i, best = 0; unsigned long nextval, bestval; - struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms); + struct mod_kallsyms *kallsyms = rcu_dereference(mod->kallsyms); struct module_memory *mod_mem; /* At worse, next value is at end of module */ @@ -332,6 +332,7 @@ int module_address_lookup(unsigned long addr, int ret = 0; struct module *mod; + guard(rcu)(); preempt_disable(); mod = __module_address(addr); if (mod) { @@ -354,7 +355,7 @@ int lookup_module_symbol_name(unsigned long addr, char *symname) { struct module *mod; - preempt_disable(); + guard(rcu)(); list_for_each_entry_rcu(mod, &modules, list) { if (mod->state == MODULE_STATE_UNFORMED) continue; @@ -366,12 +367,10 @@ int lookup_module_symbol_name(unsigned long addr, char *symname) goto out; strscpy(symname, sym, KSYM_NAME_LEN); - preempt_enable(); return 0; } } out: - preempt_enable(); return -ERANGE; } -- 2.53.0