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 X-Spam-Level: X-Spam-Status: No, score=-13.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 097BEC433DF for ; Sat, 17 Oct 2020 07:07:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C9660207BC for ; Sat, 17 Oct 2020 07:07:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602918463; bh=srSubu9UNVpIv85z4Sxt3cqVPcjn15nIxX15NjwY84E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=esSqO138Vqi/vc/F2hHotsCC3bTaYIJYfGRoB7ZsDEh/MaKH2tinRx/wVkKnVpPg3 +T6/w3+p0YRqyHbPOF/F2tTBozaSCxMUJPOd1ftC50zY/hrJDNkNX3d3ASIGkAoVE+ 1mzQkbBxcxP/C42yV6xs2nyYKqf49vfeiKWL6bJo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2437413AbgJQHHn (ORCPT ); Sat, 17 Oct 2020 03:07:43 -0400 Received: from mail.kernel.org ([198.145.29.99]:48568 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2437381AbgJQHHm (ORCPT ); Sat, 17 Oct 2020 03:07:42 -0400 Received: from localhost.localdomain (89.208.247.74.16clouds.com [89.208.247.74]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 68EA720874; Sat, 17 Oct 2020 07:07:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602918462; bh=srSubu9UNVpIv85z4Sxt3cqVPcjn15nIxX15NjwY84E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=dpzFjkTtPL811x+lpJwIUsz4HBERa5sNFmuY6mD2thtXxMi3r8T3moO1ibeuu+MVi U6jaXZnOVX0H/PB3uxz6F/ox3SyXJj59T8oLtGejlZUhLgTBZIDcSzNpOlvY/zMMo/ TqhJRCBZDvgrw+KNV19U4BzBABU96VedjFKxvadk= From: guoren@kernel.org To: palmerdabbelt@google.com, paul.walmsley@sifive.com, mhiramat@kernel.org, alankao@andestech.com, rostedt@goodmis.org Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, anup@brainfault.org, linux-csky@vger.kernel.org, greentime.hu@sifive.com, zong.li@sifive.com, guoren@kernel.org, me@packi.ch, Guo Ren Subject: [PATCH v4 9/9] riscv: Fixup lockdep_assert_held(&text_mutex) in patch_insn_write Date: Sat, 17 Oct 2020 07:06:17 +0000 Message-Id: <1602918377-23573-10-git-send-email-guoren@kernel.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1602918377-23573-1-git-send-email-guoren@kernel.org> References: <1602918377-23573-1-git-send-email-guoren@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-csky@vger.kernel.org From: Guo Ren It will cause warning messages: echo function_graph > /sys/kernel/debug/tracing/current_tracer [ 47.691397] ------------[ cut here ]------------ [ 47.692899] WARNING: CPU: 0 PID: 11 at arch/riscv/kernel/patch.c:63 patch_insn_write+0x182/0x19a [ 47.694483] Modules linked in: [ 47.695754] CPU: 0 PID: 11 Comm: migration/0 Not tainted 5.9.0-11367-g1054335 #132 [ 47.698228] epc: ffffffe000204530 ra : ffffffe00020452c sp : ffffffe0023ffc20 gp : ffffffe0013e1fe0 tp : ffffffe0023e4e00 t0 : 0000000000000000 [ 47.701872] t1 : 000000000000000e t2 : 000000000000001b s0 : ffffffe0023ffc70 s1 : ffffffe000206850 a0 : 0000000000000000 a1 : ffffffffffffffff [ 47.705550] a2 : 0000000000000000 a3 : ffffffe03af7c5e8 a4 : 0000000000000000 a5 : 0000000000000000 a6 : 0000000000000000 a7 : 00000000150b02d8 [ 47.709159] s2 : 0000000000000008 s3 : 0000000000000858 s4 : ffffffe0023ffc98 s5 : 0000000000000850 s6 : 0000000000000003 s7 : 0000000000000002 [ 47.714135] s8 : 0000000000000004 s9 : 0000000000000001 s10: 0000000000000001 s11: 0000000000000003 t3 : ffffffffffffe000 t4 : 0000000000d86254 [ 47.716574] t5 : 0000000000000005 t6 : 0000000000040000status: 0000000000000100 badaddr: 0000000000000000 cause: 0000000000000003 [ 47.720019] CPU: 0 PID: 11 Comm: migration/0 Not tainted 5.9.0-11367-g1054335 #132 [ 47.722074] Call Trace: [ 47.722561] [] walk_stackframe+0x0/0xc2 [ 47.724608] [] show_stack+0x46/0x52 [ 47.726246] [] dump_stack+0x90/0xb6 [ 47.727672] [] __warn+0x98/0xfa [ 47.729131] [] report_bug+0xaa/0x11e [ 47.730624] [] do_trap_break+0x96/0xfe [ 47.732448] [] ret_from_exception+0x0/0x14 [ 47.734341] [] patch_insn_write+0x17e/0x19a [ 47.737235] irq event stamp: 39 [ 47.738521] hardirqs last enabled at (39): [] _save_context+0xa2/0xe6 [ 47.741055] hardirqs last disabled at (38): [] multi_cpu_stop+0x130/0x166 [ 47.743551] softirqs last enabled at (0): [] copy_process+0x430/0x1316 [ 47.746031] softirqs last disabled at (0): [<0000000000000000>] 0x0 [ 47.748617] ---[ end trace 88a1054faa6524ef ]--- Because the path of stop_machine(__ftrace_modify_code)-> ftrace_modify_all_code->...->patch_insn_write has no pair of lock&unlock text_mutex, so we shouldn't put assert here. Signed-off-by: Guo Ren --- arch/riscv/kernel/patch.c | 7 ------- 1 file changed, 7 deletions(-) diff --git a/arch/riscv/kernel/patch.c b/arch/riscv/kernel/patch.c index 0b55287..2ee5063 100644 --- a/arch/riscv/kernel/patch.c +++ b/arch/riscv/kernel/patch.c @@ -55,13 +55,6 @@ static int patch_insn_write(void *addr, const void *insn, size_t len) bool across_pages = (((uintptr_t) addr & ~PAGE_MASK) + len) > PAGE_SIZE; int ret; - /* - * Before reaching here, it was expected to lock the text_mutex - * already, so we don't need to give another lock here and could - * ensure that it was safe between each cores. - */ - lockdep_assert_held(&text_mutex); - if (across_pages) patch_map(addr + len, FIX_TEXT_POKE1); -- 2.7.4