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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 AEE34C433DF for ; Thu, 21 May 2020 18:40:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 938BA206C3 for ; Thu, 21 May 2020 18:40:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729793AbgEUSkk (ORCPT ); Thu, 21 May 2020 14:40:40 -0400 Received: from smtprelay0218.hostedemail.com ([216.40.44.218]:37268 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728240AbgEUSkk (ORCPT ); Thu, 21 May 2020 14:40:40 -0400 Received: from filter.hostedemail.com (clb03-v110.bra.tucows.net [216.40.38.60]) by smtprelay08.hostedemail.com (Postfix) with ESMTP id 5D245182CED2A; Thu, 21 May 2020 18:40:39 +0000 (UTC) X-Session-Marker: 6A6F6540706572636865732E636F6D X-HE-Tag: class39_3a05a3526d20 X-Filterd-Recvd-Size: 5863 Received: from XPS-9350.home (unknown [47.151.136.130]) (Authenticated sender: joe@perches.com) by omf09.hostedemail.com (Postfix) with ESMTPA; Thu, 21 May 2020 18:40:38 +0000 (UTC) Message-ID: Subject: [PATCH] printk: Move and rename maximum printk output line length defines From: Joe Perches To: Andrew Morton , Chenggang Wang , Petr Mladek , Sergey Senozhatsky , Steven Rostedt Cc: linux-kernel@vger.kernel.org Date: Thu, 21 May 2020 11:40:35 -0700 In-Reply-To: References: Content-Type: text/plain; charset="ISO-8859-1" User-Agent: Evolution 3.36.1-2 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Make the printk output maximum line length globally available. This can be used to emit logging messages lines that exceed the single printk maximum length line. e.g.: the kernel boot command on ARM can be up to 2048 chars Miscellanea: o Prefix the defines with PRINTK_ Signed-off-by: Joe Perches Acked-by: Petr Mladek --- include/linux/printk.h | 18 ++++++++++++++++++ kernel/printk/printk.c | 28 ++++++++++------------------ 2 files changed, 28 insertions(+), 18 deletions(-) diff --git a/include/linux/printk.h b/include/linux/printk.h index 38beb97e7018..850dc4d4356f 100644 --- a/include/linux/printk.h +++ b/include/linux/printk.h @@ -43,6 +43,24 @@ static inline const char *printk_skip_headers(const char *buffer) #define CONSOLE_EXT_LOG_MAX 8192 +/* Maximum length of a single printk */ + +#ifdef CONFIG_PRINTK + +#ifdef CONFIG_PRINTK_CALLER +#define PRINTK_PREFIX_MAX 48 +#else +#define PRINTK_PREFIX_MAX 32 +#endif +#define PRINTK_LOG_LINE_MAX (1024 - PRINTK_PREFIX_MAX) + +#else + +#define PRINTK_PREFIX_MAX 0 +#define PRINTK_LOG_LINE_MAX 0 + +#endif + /* printk's without a loglevel use this.. */ #define MESSAGE_LOGLEVEL_DEFAULT CONFIG_MESSAGE_LOGLEVEL_DEFAULT diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 4f1cc4acef41..fc22a494ef0c 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -443,13 +443,6 @@ static u64 exclusive_console_stop_seq; static u64 clear_seq; static u32 clear_idx; -#ifdef CONFIG_PRINTK_CALLER -#define PREFIX_MAX 48 -#else -#define PREFIX_MAX 32 -#endif -#define LOG_LINE_MAX (1024 - PREFIX_MAX) - #define LOG_LEVEL(v) ((v) & 0x07) #define LOG_FACILITY(v) ((v) >> 3 & 0xff) @@ -825,7 +818,7 @@ static ssize_t devkmsg_write(struct kiocb *iocb, struct iov_iter *from) size_t len = iov_iter_count(from); ssize_t ret = len; - if (!user || len > LOG_LINE_MAX) + if (!user || len > PRINTK_LOG_LINE_MAX) return -EINVAL; /* Ignore when user logging is disabled. */ @@ -1341,7 +1334,7 @@ static size_t msg_print_text(const struct printk_log *msg, bool syslog, const char *text = log_text(msg); size_t text_size = msg->text_len; size_t len = 0; - char prefix[PREFIX_MAX]; + char prefix[PRINTK_PREFIX_MAX]; const size_t prefix_len = print_prefix(msg, syslog, time, prefix); do { @@ -1382,7 +1375,7 @@ static int syslog_print(char __user *buf, int size) struct printk_log *msg; int len = 0; - text = kmalloc(LOG_LINE_MAX + PREFIX_MAX, GFP_KERNEL); + text = kmalloc(PRINTK_LOG_LINE_MAX + PRINTK_PREFIX_MAX, GFP_KERNEL); if (!text) return -ENOMEM; @@ -1412,7 +1405,7 @@ static int syslog_print(char __user *buf, int size) skip = syslog_partial; msg = log_from_idx(syslog_idx); n = msg_print_text(msg, true, syslog_time, text, - LOG_LINE_MAX + PREFIX_MAX); + PRINTK_LOG_LINE_MAX + PRINTK_PREFIX_MAX); if (n - syslog_partial <= size) { /* message fits into buffer, move forward */ syslog_idx = log_next(syslog_idx); @@ -1454,7 +1447,7 @@ static int syslog_print_all(char __user *buf, int size, bool clear) u32 idx; bool time; - text = kmalloc(LOG_LINE_MAX + PREFIX_MAX, GFP_KERNEL); + text = kmalloc(PRINTK_LOG_LINE_MAX + PRINTK_PREFIX_MAX, GFP_KERNEL); if (!text) return -ENOMEM; @@ -1492,7 +1485,8 @@ static int syslog_print_all(char __user *buf, int size, bool clear) while (len >= 0 && seq < next_seq) { struct printk_log *msg = log_from_idx(idx); int textlen = msg_print_text(msg, true, time, text, - LOG_LINE_MAX + PREFIX_MAX); + PRINTK_LOG_LINE_MAX + + PRINTK_PREFIX_MAX); idx = log_next(idx); seq++; @@ -1845,7 +1839,7 @@ static inline u32 printk_caller_id(void) * reached the console in case of a kernel crash. */ static struct cont { - char buf[LOG_LINE_MAX]; + char buf[PRINTK_LOG_LINE_MAX]; size_t len; /* length == 0 means unused buffer */ u32 caller_id; /* printk_caller_id() of first print */ u64 ts_nsec; /* time of first print */ @@ -1931,7 +1925,7 @@ int vprintk_store(int facility, int level, const char *dict, size_t dictlen, const char *fmt, va_list args) { - static char textbuf[LOG_LINE_MAX]; + static char textbuf[PRINTK_LOG_LINE_MAX]; char *text = textbuf; size_t text_len; enum log_flags lflags = 0; @@ -2088,8 +2082,6 @@ EXPORT_SYMBOL(printk); #else /* CONFIG_PRINTK */ -#define LOG_LINE_MAX 0 -#define PREFIX_MAX 0 #define printk_time false static u64 syslog_seq; @@ -2396,7 +2388,7 @@ static inline int can_use_console(void) void console_unlock(void) { static char ext_text[CONSOLE_EXT_LOG_MAX]; - static char text[LOG_LINE_MAX + PREFIX_MAX]; + static char text[PRINTK_LOG_LINE_MAX + PRINTK_PREFIX_MAX]; unsigned long flags; bool do_cond_resched, retry;