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=-9.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,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 5BBE2C0044D for ; Mon, 16 Mar 2020 14:42:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 276B02051A for ; Mon, 16 Mar 2020 14:42:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=arista.com header.i=@arista.com header.b="h2FlJSNh" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731916AbgCPOmn (ORCPT ); Mon, 16 Mar 2020 10:42:43 -0400 Received: from mail-pj1-f67.google.com ([209.85.216.67]:37258 "EHLO mail-pj1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731589AbgCPOml (ORCPT ); Mon, 16 Mar 2020 10:42:41 -0400 Received: by mail-pj1-f67.google.com with SMTP id ca13so8824511pjb.2 for ; Mon, 16 Mar 2020 07:42:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=arista.com; s=googlenew; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=R3WlkMq8F0DL+8HOyrBobJIXLwasaELBzuoWoB4z8LM=; b=h2FlJSNhqQea8YRgUjseza/AiVqSrTPb0VA9vJos6CxzbeAl+SPE5yxKqylPiaTRFx Fe973kXwvy2nN/DBx745rnln1fjp6eoXO7JGUx0s+O15Tmp56NvYzcLo9KrrNT76EoGP zpiCPRyZDH7NAtcXtIbprCX3gnXQ54KARECzrMN3EhvSSV7fSDS11P8RUco2dtoNzJsE +iI39aIzYUfTR2nmhwJc2M8sLmuSyW+NJve7uRJjkWrAvy1zAe3Pp/CgJuzeLCLt8HjQ 7Teh+Ev/7JwjVWvEeLEX8IQjKl0PrG9Pm15vurctOPIuxiiC6s4oawscQ5j+DsoLGDKs CP8g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=R3WlkMq8F0DL+8HOyrBobJIXLwasaELBzuoWoB4z8LM=; b=k+jf9/95/FokoVsps4qdsmGJks5WPTKS2jH/4VSvnUT95/KB27RcvdAP1/sKOkuWVe PcNFCT+/yw0uaousFkAH89EyCwItQl/nQulrrhtcuQ+hTVNrhq39zA346kWVrwvpsLRU IhRlX5F8K1NNSty/48owQsIZFIdmpSSuakd57Asww2xMKGi7QgRIXeEyQHvH0BuqLsZR oPzIJupAT+oXJ5FPslVrVE+N46MtBWEllfXX89QC9PSutmy6pGsPOniOI5e6eTw1EcVf Q07lxGYal7qlY195V1ZKPxPsq+sNWOHPiB8j3s+wLnKtPTrqOChD5N62aXIZQGAAy2rO lkVQ== X-Gm-Message-State: ANhLgQ2Rf5VJTkiK0HfZcs3Q00zudLqYoKZdyn+udhdsqJmxQLfe55bH /n/RV/T1Ond7R5Yxrs8CpxVcqmVRJQT8BA== X-Google-Smtp-Source: ADFU+vvKPXCoJUUr3rHWxh4j6KZyTXYB5MQOyJngIPdBM0959euYJG8rAEGWfQPQz3Sg5wroZ/3Ycw== X-Received: by 2002:a17:90a:350d:: with SMTP id q13mr25248329pjb.171.1584369759940; Mon, 16 Mar 2020 07:42:39 -0700 (PDT) Received: from Mindolluin.aristanetworks.com ([2a02:8084:e84:2480:228:f8ff:fe6f:83a8]) by smtp.gmail.com with ESMTPSA id i2sm81524pjs.21.2020.03.16.07.42.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 16 Mar 2020 07:42:39 -0700 (PDT) From: Dmitry Safonov To: linux-kernel@vger.kernel.org Cc: Dmitry Safonov <0x7f454c46@gmail.com>, Dmitry Safonov , Andrew Morton , Greg Kroah-Hartman , Ingo Molnar , Jiri Slaby , Petr Mladek , Sergey Senozhatsky , Steven Rostedt , Tetsuo Handa , Borislav Petkov , "H. Peter Anvin" , Ingo Molnar , Thomas Gleixner , x86@kernel.org Subject: [PATCHv2 40/50] x86: Add missing const qualifiers for log_lvl Date: Mon, 16 Mar 2020 14:39:06 +0000 Message-Id: <20200316143916.195608-41-dima@arista.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200316143916.195608-1-dima@arista.com> References: <20200316143916.195608-1-dima@arista.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. Keep log_lvl const show_trace_log_lvl() and printk_stack_address() as the new generic show_stack_loglvl() wants to have a proper const qualifier. And gcc rightfully produces warnings in case it's not keept: arch/x86/kernel/dumpstack.c: In function ‘show_stack’: arch/x86/kernel/dumpstack.c:294:37: warning: passing argument 4 of ‘show_trace_log_lv ’ discards ‘const’ qualifier from pointer target type [-Wdiscarded-qualifiers] 294 | show_trace_log_lvl(task, NULL, sp, loglvl); | ^~~~~~ arch/x86/kernel/dumpstack.c:163:32: note: expected ‘char *’ but argument is of type ‘const char *’ 163 | unsigned long *stack, char *log_lvl) | ~~~~~~^~~~~~~ Cc: Borislav Petkov Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Thomas Gleixner Cc: x86@kernel.org [1]: https://lore.kernel.org/lkml/20190528002412.1625-1-dima@arista.com/T/#u Signed-off-by: Dmitry Safonov --- arch/x86/include/asm/stacktrace.h | 2 +- arch/x86/kernel/dumpstack.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/x86/include/asm/stacktrace.h b/arch/x86/include/asm/stacktrace.h index 14db05086bbf..5ae5a68e469d 100644 --- a/arch/x86/include/asm/stacktrace.h +++ b/arch/x86/include/asm/stacktrace.h @@ -87,7 +87,7 @@ get_stack_pointer(struct task_struct *task, struct pt_regs *regs) } void show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs, - unsigned long *stack, char *log_lvl); + unsigned long *stack, const char *log_lvl); /* The form of the top of the frame on the stack */ struct stack_frame { diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c index ae64ec7f752f..b94bc31a1757 100644 --- a/arch/x86/kernel/dumpstack.c +++ b/arch/x86/kernel/dumpstack.c @@ -65,7 +65,7 @@ bool in_entry_stack(unsigned long *stack, struct stack_info *info) } static void printk_stack_address(unsigned long address, int reliable, - char *log_lvl) + const char *log_lvl) { touch_nmi_watchdog(); printk("%s %s%pB\n", log_lvl, reliable ? "" : "? ", (void *)address); @@ -160,7 +160,7 @@ static void show_regs_if_on_stack(struct stack_info *info, struct pt_regs *regs, } void show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs, - unsigned long *stack, char *log_lvl) + unsigned long *stack, const char *log_lvl) { struct unwind_state state; struct stack_info stack_info = {0}; -- 2.25.1