From nobody Fri Jun 19 06:13:34 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0D1FBC433F5 for ; Thu, 7 Apr 2022 07:34:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241856AbiDGHgF (ORCPT ); Thu, 7 Apr 2022 03:36:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45370 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241822AbiDGHf6 (ORCPT ); Thu, 7 Apr 2022 03:35:58 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C0B0018B300; Thu, 7 Apr 2022 00:33:59 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 5A00861D95; Thu, 7 Apr 2022 07:33:59 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 43CB7C385A4; Thu, 7 Apr 2022 07:33:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1649316838; bh=4wIhTQJZp3+FhQY+sjwWCoJ1fY2jda3dTtRoplMPuzA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qT2zXYE3CQHTLuX5QZZPQHikYbHh7VPe0bAHwwvmUvmMUnWQIyfU+k7F3AfDIvyRi DbQJ6qiQIryUX2TPGaCeCLRIsJKYDUtVi2eW9wk/oS4lUJw8TeMVaDawYhr+g7X8U3 BD/tIW0R3G5pA+cnnSBuTCL9yC6b2NqcdjvEtbeyIEFds6kbkFoaEJ60l1CqnYGp5C wuxNx22nM3sMr0zTrDhJ0Z36oEmgAqj8rk2NkpqWkUNRDlvhwyx3zToIQurA2FvotF fTUpZW/MoL2A1cwRv4njUeB8q1emqKBkULf3pSwP3zJi7/NivB+2LX/3X/WfQDDEH9 88qBx7bdrkZLg== From: guoren@kernel.org To: guoren@kernel.org, arnd@arndb.de, gregkh@linuxfoundation.org Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, linux-csky@vger.kernel.org, linux-xtensa@linux-xtensa.org, linux-riscv@lists.infradead.org, linux-arm-kernel@lists.infradead.org, Guo Ren , Catalin Marinas , Masami Hiramatsu , stable@vger.kernel.org Subject: [PATCH V4 1/4] arm64: patch_text: Fixup last cpu should be master Date: Thu, 7 Apr 2022 15:33:20 +0800 Message-Id: <20220407073323.743224-2-guoren@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220407073323.743224-1-guoren@kernel.org> References: <20220407073323.743224-1-guoren@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Guo Ren These patch_text implementations are using stop_machine_cpuslocked infrastructure with atomic cpu_count. The original idea: When the master CPU patch_text, the others should wait for it. But current implementation is using the first CPU as master, which couldn't guarantee the remaining CPUs are waiting. This patch changes the last CPU as the master to solve the potential risk. Fixes: ae16480785de ("arm64: introduce interfaces to hotpatch kernel and mo= dule code") Signed-off-by: Guo Ren Signed-off-by: Guo Ren Reviewed-by: Catalin Marinas Reviewed-by: Masami Hiramatsu Cc: --- arch/arm64/kernel/patching.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kernel/patching.c b/arch/arm64/kernel/patching.c index 771f543464e0..33e0fabc0b79 100644 --- a/arch/arm64/kernel/patching.c +++ b/arch/arm64/kernel/patching.c @@ -117,8 +117,8 @@ static int __kprobes aarch64_insn_patch_text_cb(void *a= rg) int i, ret =3D 0; struct aarch64_insn_patch *pp =3D arg; =20 - /* The first CPU becomes master */ - if (atomic_inc_return(&pp->cpu_count) =3D=3D 1) { + /* The last CPU becomes master */ + if (atomic_inc_return(&pp->cpu_count) =3D=3D num_online_cpus()) { for (i =3D 0; ret =3D=3D 0 && i < pp->insn_cnt; i++) ret =3D aarch64_insn_patch_text_nosync(pp->text_addrs[i], pp->new_insns[i]); --=20 2.25.1 From nobody Fri Jun 19 06:13:34 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0A0F1C433FE for ; Thu, 7 Apr 2022 07:34:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241882AbiDGHgO (ORCPT ); Thu, 7 Apr 2022 03:36:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46218 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241864AbiDGHgJ (ORCPT ); Thu, 7 Apr 2022 03:36:09 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7DD111903C8; Thu, 7 Apr 2022 00:34:08 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 3A298B826B6; Thu, 7 Apr 2022 07:34:07 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 393E2C385A9; Thu, 7 Apr 2022 07:33:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1649316845; bh=Lq9EhyRijx1cfe4dEDp+AdieXvyyIhRaAjpvB7W8v1s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hMVhkWDgaKW7xR+gIWxFoU2fJjcz2m9cvJ8rHJeSJCXIE8aZFvMrAW/BStymn+T2e 0rQr1eouZWS72DT7IKe+1k5LDSIb14lGiB+icEK/brzv4tOvm8icRFHRL95VcKxtUL WKlxZBpH7tUCydPdcBBWDN6RxszZJ113iYYEws+rF9PPybUOBUyLvUzANlkMGkcX6J V+sqIB/OYIjO02NwbgMFGYlRo3P75PgRvJOHwQGjrpv/mhYTLklZFHQlBWW93nWPqX 2nkdfKPS73HXnFtJXT6u/bToYSDyfA66rkbKPTRPvu2a9yU44xYRjRQmhcb0/elX+b bV5un3MkOIEFw== From: guoren@kernel.org To: guoren@kernel.org, arnd@arndb.de, gregkh@linuxfoundation.org Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, linux-csky@vger.kernel.org, linux-xtensa@linux-xtensa.org, linux-riscv@lists.infradead.org, linux-arm-kernel@lists.infradead.org, Guo Ren , Masami Hiramatsu , stable@vger.kernel.org Subject: [PATCH V4 2/4] riscv: patch_text: Fixup last cpu should be master Date: Thu, 7 Apr 2022 15:33:21 +0800 Message-Id: <20220407073323.743224-3-guoren@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220407073323.743224-1-guoren@kernel.org> References: <20220407073323.743224-1-guoren@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Guo Ren These patch_text implementations are using stop_machine_cpuslocked infrastructure with atomic cpu_count. The original idea: When the master CPU patch_text, the others should wait for it. But current implementation is using the first CPU as master, which couldn't guarantee the remaining CPUs are waiting. This patch changes the last CPU as the master to solve the potential risk. Fixes: 043cb41a85de ("riscv: introduce interfaces to patch kernel code") Signed-off-by: Guo Ren Signed-off-by: Guo Ren Reviewed-by: Masami Hiramatsu Cc: --- arch/riscv/kernel/patch.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/riscv/kernel/patch.c b/arch/riscv/kernel/patch.c index 0b552873a577..765004b60513 100644 --- a/arch/riscv/kernel/patch.c +++ b/arch/riscv/kernel/patch.c @@ -104,7 +104,7 @@ static int patch_text_cb(void *data) struct patch_insn *patch =3D data; int ret =3D 0; =20 - if (atomic_inc_return(&patch->cpu_count) =3D=3D 1) { + if (atomic_inc_return(&patch->cpu_count) =3D=3D num_online_cpus()) { ret =3D patch_text_nosync(patch->addr, &patch->insn, GET_INSN_LENGTH(patch->insn)); --=20 2.25.1 From nobody Fri Jun 19 06:13:34 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 17766C433FE for ; Thu, 7 Apr 2022 07:34:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241874AbiDGHg2 (ORCPT ); Thu, 7 Apr 2022 03:36:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46560 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241863AbiDGHgQ (ORCPT ); Thu, 7 Apr 2022 03:36:16 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DB968194FF3; Thu, 7 Apr 2022 00:34:17 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 8BD9CB826C7; Thu, 7 Apr 2022 07:34:16 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7A285C385A4; Thu, 7 Apr 2022 07:34:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1649316855; bh=R2FPA9lWSXRgAzEvdehN22kFHU9pjAW3rQXXGDs7cDQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OJlKMZ2aKAzw5+LeIolJB5pwRD23zC0v1DrROL+aQ2kRGcMIIsMaieRXUWJ7LPfML nyQDGC2U5D8LolVa+curnmQgS1G1eTqJU6hy8o/PK6TXWuqokCFmrNHffffMrLMcA6 eoih0F/3+r8HL51n2Y7mCAaPGw3hQ8FZazxhD6WzjaSFyku4Tu+I6JekSksdCexMLf 9i77RxagVWEuZ+JIeMVfyempj2xEj4HBmmTL0UVXgD1ZAMhk1YTlOJcfiQVibNXquT I877fj9qjzdWkWW46gJ59BkzmgKvL4eg2L9Nj5v0EgdHTWjw9L4HN2Dni12GE86edn Y8htB1f4ONb3Q== From: guoren@kernel.org To: guoren@kernel.org, arnd@arndb.de, gregkh@linuxfoundation.org Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, linux-csky@vger.kernel.org, linux-xtensa@linux-xtensa.org, linux-riscv@lists.infradead.org, linux-arm-kernel@lists.infradead.org, Guo Ren , Max Filippov , Masami Hiramatsu , stable@vger.kernel.org Subject: [PATCH V4 3/4] xtensa: patch_text: Fixup last cpu should be master Date: Thu, 7 Apr 2022 15:33:22 +0800 Message-Id: <20220407073323.743224-4-guoren@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220407073323.743224-1-guoren@kernel.org> References: <20220407073323.743224-1-guoren@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Guo Ren These patch_text implementations are using stop_machine_cpuslocked infrastructure with atomic cpu_count. The original idea: When the master CPU patch_text, the others should wait for it. But current implementation is using the first CPU as master, which couldn't guarantee the remaining CPUs are waiting. This patch changes the last CPU as the master to solve the potential risk. Fixes: 64711f9a47d4 ("xtensa: implement jump_label support") Signed-off-by: Guo Ren Signed-off-by: Guo Ren Reviewed-by: Max Filippov Reviewed-by: Masami Hiramatsu Cc: --- arch/xtensa/kernel/jump_label.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/xtensa/kernel/jump_label.c b/arch/xtensa/kernel/jump_labe= l.c index 0dde21e0d3de..ad1841cecdfb 100644 --- a/arch/xtensa/kernel/jump_label.c +++ b/arch/xtensa/kernel/jump_label.c @@ -40,7 +40,7 @@ static int patch_text_stop_machine(void *data) { struct patch *patch =3D data; =20 - if (atomic_inc_return(&patch->cpu_count) =3D=3D 1) { + if (atomic_inc_return(&patch->cpu_count) =3D=3D num_online_cpus()) { local_patch_text(patch->addr, patch->data, patch->sz); atomic_inc(&patch->cpu_count); } else { --=20 2.25.1 From nobody Fri Jun 19 06:13:34 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C777CC433F5 for ; Thu, 7 Apr 2022 07:35:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241866AbiDGHhB (ORCPT ); Thu, 7 Apr 2022 03:37:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47142 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240343AbiDGHgo (ORCPT ); Thu, 7 Apr 2022 03:36:44 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2DEF119E396; Thu, 7 Apr 2022 00:34:36 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 89E4CB826C8; Thu, 7 Apr 2022 07:34:34 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1673CC385A4; Thu, 7 Apr 2022 07:34:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1649316873; bh=1ucMhnW8irziJNfuECEH3MHXjDK0nSaVyUwaETtw+gM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KelGW/uTUVx5N9Sv2N8w8R9JRf21b8/HoKoyaUYPNOJgWfIKzQiF7OA1rp6QJv+BJ ytq/FiqmKFGSs0Sfa/N6mEuTZZcNJZCxF2cXvcwjhXcqSOTZQOSw+U0ZP4WPx9hrTG Igt3l6DJxAD6TkFv//g0cb7uzlxGM9LBCU/dDhX1u+m2/qq5O7bjJE8Kir697/BF/C gPykEqhRL5iAJtMqzxMZC1C51u9klzBs0AiIiqvKs+dxQdsK35GL29VVfT3QNbarg4 8fcYqEARmNuNjvOoZkd1vpBFpU1v2Bx7dFPjVeYLo38goAcOYyknOr6/WuWAhMceSM MC/wBEJ5daT5A== From: guoren@kernel.org To: guoren@kernel.org, arnd@arndb.de, gregkh@linuxfoundation.org Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, linux-csky@vger.kernel.org, linux-xtensa@linux-xtensa.org, linux-riscv@lists.infradead.org, linux-arm-kernel@lists.infradead.org, Guo Ren , Masami Hiramatsu , stable@vger.kernel.org Subject: [PATCH V4 4/4] csky: patch_text: Fixup last cpu should be master Date: Thu, 7 Apr 2022 15:33:23 +0800 Message-Id: <20220407073323.743224-5-guoren@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220407073323.743224-1-guoren@kernel.org> References: <20220407073323.743224-1-guoren@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Guo Ren These patch_text implementations are using stop_machine_cpuslocked infrastructure with atomic cpu_count. The original idea: When the master CPU patch_text, the others should wait for it. But current implementation is using the first CPU as master, which couldn't guarantee the remaining CPUs are waiting. This patch changes the last CPU as the master to solve the potential risk. Fixes: 33e53ae1ce41 ("csky: Add kprobes supported") Signed-off-by: Guo Ren Signed-off-by: Guo Ren Reviewed-by: Masami Hiramatsu Cc: --- arch/csky/kernel/probes/kprobes.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/csky/kernel/probes/kprobes.c b/arch/csky/kernel/probes/kp= robes.c index 42920f25e73c..34ba684d5962 100644 --- a/arch/csky/kernel/probes/kprobes.c +++ b/arch/csky/kernel/probes/kprobes.c @@ -30,7 +30,7 @@ static int __kprobes patch_text_cb(void *priv) struct csky_insn_patch *param =3D priv; unsigned int addr =3D (unsigned int)param->addr; =20 - if (atomic_inc_return(¶m->cpu_count) =3D=3D 1) { + if (atomic_inc_return(¶m->cpu_count) =3D=3D num_online_cpus()) { *(u16 *) addr =3D cpu_to_le16(param->opcode); dcache_wb_range(addr, addr + 2); atomic_inc(¶m->cpu_count); --=20 2.25.1