From patchwork Thu Nov 25 11:39:32 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tiezhu Yang X-Patchwork-Id: 12638967 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 58DB0C433F5 for ; Thu, 25 Nov 2021 11:41:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233289AbhKYLos (ORCPT ); Thu, 25 Nov 2021 06:44:48 -0500 Received: from mail.loongson.cn ([114.242.206.163]:45486 "EHLO loongson.cn" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S235144AbhKYLms (ORCPT ); Thu, 25 Nov 2021 06:42:48 -0500 Received: from linux.localdomain (unknown [113.200.148.30]) by mail.loongson.cn (Coremail) with SMTP id AQAAf9AxZ+j1dZ9hTVoBAA--.6082S2; Thu, 25 Nov 2021 19:39:34 +0800 (CST) From: Tiezhu Yang To: Thomas Bogendoerfer Cc: Xuefeng Li , linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2] MIPS: Fix using smp_processor_id() in preemptible in show_cpuinfo() Date: Thu, 25 Nov 2021 19:39:32 +0800 Message-Id: <1637840372-27773-1-git-send-email-yangtiezhu@loongson.cn> X-Mailer: git-send-email 2.1.0 X-CM-TRANSID: AQAAf9AxZ+j1dZ9hTVoBAA--.6082S2 X-Coremail-Antispam: 1UD129KBjvJXoW7WF47JF1Dur17Zr47ZryftFb_yoW8Zr4rpa y7Ar1Utr4UWw4UJas5JrZ3uryrXFs8Za42kayxJ3y3Z3W5Wr1DXrnagF47uFyqgr1rta1I gF9Fqr4Yqry8ZaUanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUkl14x267AKxVWUJVW8JwAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK02 1l84ACjcxK6xIIjxv20xvE14v26ryj6F1UM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26r4U JVWxJr1l84ACjcxK6I8E87Iv67AKxVW0oVCq3wA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_Gc CE3s1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4CE5I8CrVC2j2WlYx0E 2Ix0cI8IcVAFwI0_JrI_JrylYx0Ex4A2jsIE14v26r4j6F4UMcvjeVCFs4IE7xkEbVWUJV W8JwACjcxG0xvY0x0EwIxGrwACjI8F5VA0II8E6IAqYI8I648v4I1lc2xSY4AK67AK6r4k MxAIw28IcxkI7VAKI48JMxC20s026xCaFVCjc4AY6r1j6r4UMI8I3I0E5I8CrVAFwI0_Jr 0_Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE17CEb7AF67AKxVWUAVWUtwCIc40Y0x0E wIxGrwCI42IY6xIIjxv20xvE14v26r1j6r1xMIIF0xvE2Ix0cI8IcVCY1x0267AKxVWUJV W8JwCI42IY6xAIw20EY4v20xvaj40_Wr1j6rW3Jr1lIxAIcVC2z280aVAFwI0_Jr0_Gr1l IxAIcVC2z280aVCY1x0267AKxVW8JVW8JrUvcSsGvfC2KfnxnUUI43ZEXa7VUjTa0PUUUU U== X-CM-SenderInfo: p1dqw3xlh2x3gn0dqz5rrqw2lrqou0/ Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org There exists the following issue under DEBUG_PREEMPT: BUG: using smp_processor_id() in preemptible [00000000] code: systemd/1 caller is show_cpuinfo+0x460/0xea0 ... Call Trace: [] show_stack+0x94/0x128 [] dump_stack_lvl+0x94/0xd8 [] check_preemption_disabled+0x104/0x110 [] show_cpuinfo+0x460/0xea0 [] seq_read_iter+0xfc/0x4f8 [] new_sync_read+0x110/0x1b8 [] vfs_read+0x1b4/0x1d0 [] ksys_read+0xd0/0x110 [] syscall_common+0x34/0x58 We can see the following call trace: show_cpuinfo() cpu_has_fpu current_cpu_data smp_processor_id() $ addr2line -f -e vmlinux 0xffffffff802209c8 show_cpuinfo arch/mips/kernel/proc.c:188 $ head -188 arch/mips/kernel/proc.c | tail -1 if (cpu_has_fpu) arch/mips/include/asm/cpu-features.h # define cpu_has_fpu (current_cpu_data.options & MIPS_CPU_FPU) arch/mips/include/asm/cpu-info.h #define current_cpu_data cpu_data[smp_processor_id()] Based on the above analysis, fix the issue by using raw_cpu_has_fpu which calls raw_smp_processor_id() in show_cpuinfo(). Fixes: 626bfa037299 ("MIPS: kernel: proc: add CPU option reporting") Signed-off-by: Tiezhu Yang --- arch/mips/kernel/proc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/mips/kernel/proc.c b/arch/mips/kernel/proc.c index 376a6e2..9f47a88 100644 --- a/arch/mips/kernel/proc.c +++ b/arch/mips/kernel/proc.c @@ -185,7 +185,7 @@ static int show_cpuinfo(struct seq_file *m, void *v) seq_puts(m, " tx39_cache"); if (cpu_has_octeon_cache) seq_puts(m, " octeon_cache"); - if (cpu_has_fpu) + if (raw_cpu_has_fpu) seq_puts(m, " fpu"); if (cpu_has_32fpr) seq_puts(m, " 32fpr");