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=-3.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 AFB00C433E1 for ; Tue, 9 Jun 2020 04:30:13 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 71B2E20810 for ; Tue, 9 Jun 2020 04:30:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="afItEduu" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 71B2E20810 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 2648D6B000A; Tue, 9 Jun 2020 00:30:13 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 215B66B000C; Tue, 9 Jun 2020 00:30:13 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 12BD76B000D; Tue, 9 Jun 2020 00:30:13 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0216.hostedemail.com [216.40.44.216]) by kanga.kvack.org (Postfix) with ESMTP id EC45D6B000A for ; Tue, 9 Jun 2020 00:30:12 -0400 (EDT) Received: from smtpin10.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id AC067804D143 for ; Tue, 9 Jun 2020 04:30:12 +0000 (UTC) X-FDA: 76908396264.10.gun34_2414c0c26dbf Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin10.hostedemail.com (Postfix) with ESMTP id 77BB816A4C2 for ; Tue, 9 Jun 2020 04:30:12 +0000 (UTC) X-HE-Tag: gun34_2414c0c26dbf X-Filterd-Recvd-Size: 5024 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf11.hostedemail.com (Postfix) with ESMTP for ; Tue, 9 Jun 2020 04:30:12 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 15B33207F9; Tue, 9 Jun 2020 04:30:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591677011; bh=nGuceUJd46jy46xIHXcS+LvMOWH+78c+K1NCVoq040Q=; h=Date:From:To:Subject:In-Reply-To:From; b=afItEduuAgLq8I6mn2b0cba6SmIw4xZ7rq7TmzFNEc+KCnS+k26Z2qlmcHV/aP/wj 4wBn/z3ghzMh35uaDkIn7ibI+eDiRXdNThz4kpq2/qcQ9aYmpBFDO5WGx84hVEWJkN 30ooK0DvRDT5ECSmmClkZypFZdKL6SxB01NLVm3w= Date: Mon, 08 Jun 2020 21:30:10 -0700 From: Andrew Morton To: akpm@linux-foundation.org, dima@arista.com, linux-mm@kvack.org, linux@armlinux.org.uk, mm-commits@vger.kernel.org, torvalds@linux-foundation.org, will@kernel.org Subject: [patch 05/93] arm: add loglvl to unwind_backtrace() Message-ID: <20200609043010.ZyJC0il_f%akpm@linux-foundation.org> In-Reply-To: <20200608212922.5b7fa74ca3f4e2444441b7f9@linux-foundation.org> User-Agent: s-nail v14.8.16 X-Rspamd-Queue-Id: 77BB816A4C2 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam02 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: From: Dmitry Safonov Subject: arm: add loglvl to unwind_backtrace() Currently, the log-level of show_stack() depends on a platform realization. It creates situations where the headers are printed with lower log level or higher than the stacktrace (depending on a platform or user). Furthermore, it forces the logic decision from user to an architecture side. In result, some users as sysrq/kdb/etc are doing tricks with temporary rising console_loglevel while printing their messages. And in result it not only may print unwanted messages from other CPUs, but also omit printing at all in the unlucky case where the printk() was deferred. Introducing log-level parameter and KERN_UNSUPPRESSED [1] seems an easier approach than introducing more printk buffers. Also, it will consolidate printings with headers. Add log level argument to unwind_backtrace() as a preparation for introducing show_stack_loglvl(). As a good side-effect arm_syscall() is now printing errors with the same log level as the backtrace. [1]: https://lore.kernel.org/lkml/20190528002412.1625-1-dima@arista.com/T/#u Link: http://lkml.kernel.org/r/20200418201944.482088-6-dima@arista.com Signed-off-by: Dmitry Safonov Cc: Russell King Cc: Will Deacon Signed-off-by: Andrew Morton --- arch/arm/include/asm/unwind.h | 3 ++- arch/arm/kernel/traps.c | 6 +++--- arch/arm/kernel/unwind.c | 5 +++-- 3 files changed, 8 insertions(+), 6 deletions(-) --- a/arch/arm/include/asm/unwind.h~arm-add-loglvl-to-unwind_backtrace +++ a/arch/arm/include/asm/unwind.h @@ -36,7 +36,8 @@ extern struct unwind_table *unwind_table unsigned long text_addr, unsigned long text_size); extern void unwind_table_del(struct unwind_table *tab); -extern void unwind_backtrace(struct pt_regs *regs, struct task_struct *tsk); +extern void unwind_backtrace(struct pt_regs *regs, struct task_struct *tsk, + const char *loglvl); #endif /* !__ASSEMBLY__ */ --- a/arch/arm/kernel/traps.c~arm-add-loglvl-to-unwind_backtrace +++ a/arch/arm/kernel/traps.c @@ -204,7 +204,7 @@ static void dump_instr(const char *lvl, #ifdef CONFIG_ARM_UNWIND static inline void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) { - unwind_backtrace(regs, tsk); + unwind_backtrace(regs, tsk, KERN_DEFAULT); } #else static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) @@ -664,10 +664,10 @@ asmlinkage int arm_syscall(int no, struc if (user_debug & UDBG_SYSCALL) { pr_err("[%d] %s: arm syscall %d\n", task_pid_nr(current), current->comm, no); - dump_instr("", regs); + dump_instr(KERN_ERR, regs); if (user_mode(regs)) { __show_regs(regs); - c_backtrace(frame_pointer(regs), processor_mode(regs), NULL); + c_backtrace(frame_pointer(regs), processor_mode(regs), KERN_ERR); } } #endif --- a/arch/arm/kernel/unwind.c~arm-add-loglvl-to-unwind_backtrace +++ a/arch/arm/kernel/unwind.c @@ -455,7 +455,8 @@ int unwind_frame(struct stackframe *fram return URC_OK; } -void unwind_backtrace(struct pt_regs *regs, struct task_struct *tsk) +void unwind_backtrace(struct pt_regs *regs, struct task_struct *tsk, + const char *loglvl) { struct stackframe frame; @@ -493,7 +494,7 @@ void unwind_backtrace(struct pt_regs *re urc = unwind_frame(&frame); if (urc < 0) break; - dump_backtrace_entry(where, frame.pc, frame.sp - 4, NULL); + dump_backtrace_entry(where, frame.pc, frame.sp - 4, loglvl); } } _