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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 2E60BC4332D for ; Thu, 18 Feb 2021 09:40:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DED2664E5F for ; Thu, 18 Feb 2021 09:40:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232033AbhBRJcS (ORCPT ); Thu, 18 Feb 2021 04:32:18 -0500 Received: from Galois.linutronix.de ([193.142.43.55]:50588 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230514AbhBRITt (ORCPT ); Thu, 18 Feb 2021 03:19:49 -0500 From: John Ogness DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1613636302; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=jpms4UHG5lYw1f4g258FYWdkRPP5f7Th8WlLi8oO1GA=; b=4wbv4R5wX3Lkni0lOZdkvpmFuc8DPWXld5NPpOdNOHzmuvJev+5D9PilFl45Yu77csRdBv EbjhFMAAAKKhRwtoqW7eF02cPiC0yJEkDMFSIm1ZZFs/OZ2Uz8IawVQlOgo4c59lJqEbP/ DmVDQElO7Q4k2qQtK83pX+hAqHNbJNXNMBvdeVhFN3Pp4RAOC4DUPkRNfTtA0V9RIkHSQX 6/KaojokvdYPXRO6NxWKsnN0g02igN5dbU97aO8LXkYuCFqZlH9QUhPSq1n+xu/zLPwzzS oKLifIph/dEC3UMX+LPxf0/yT6nE0N4dfI9zxyhfeZG3wnIB40ggIvDSajeVDg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1613636302; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=jpms4UHG5lYw1f4g258FYWdkRPP5f7Th8WlLi8oO1GA=; b=Asy70bWcarUVvmv9IEn61mFi68gvQ4og7Z/7GHFHTS62fDk/8MPLazx0k2j8SV+cQr0meH c9Xsz9Ezf089ErBA== To: Petr Mladek Cc: Sergey Senozhatsky , Sergey Senozhatsky , Steven Rostedt , Thomas Gleixner , linux-kernel@vger.kernel.org Subject: [PATCH printk-rework 12/14] printk: kmsg_dump: remove _nolock() variants Date: Thu, 18 Feb 2021 09:18:15 +0100 Message-Id: <20210218081817.28849-13-john.ogness@linutronix.de> In-Reply-To: <20210218081817.28849-1-john.ogness@linutronix.de> References: <20210218081817.28849-1-john.ogness@linutronix.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org kmsg_dump_rewind() and kmsg_dump_get_line() are lockless, so there is no need for _nolock() variants. Remove these functions and switch all callers of the _nolock() variants. The functions without _nolock() were chosen because they are already exported to kernel modules. Signed-off-by: John Ogness --- arch/powerpc/xmon/xmon.c | 4 +-- include/linux/kmsg_dump.h | 18 +---------- kernel/debug/kdb/kdb_main.c | 8 ++--- kernel/printk/printk.c | 60 +++++-------------------------------- 4 files changed, 15 insertions(+), 75 deletions(-) diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c index 43162b885259..4cac114ba32d 100644 --- a/arch/powerpc/xmon/xmon.c +++ b/arch/powerpc/xmon/xmon.c @@ -3015,9 +3015,9 @@ dump_log_buf(void) catch_memory_errors = 1; sync(); - kmsg_dump_rewind_nolock(&iter); + kmsg_dump_rewind(&iter); xmon_start_pagination(); - while (kmsg_dump_get_line_nolock(&iter, false, buf, sizeof(buf), &len)) { + while (kmsg_dump_get_line(&iter, false, buf, sizeof(buf), &len)) { buf[len] = '\0'; printf("%s", buf); } diff --git a/include/linux/kmsg_dump.h b/include/linux/kmsg_dump.h index 2fdb10ab1799..86673930c8ea 100644 --- a/include/linux/kmsg_dump.h +++ b/include/linux/kmsg_dump.h @@ -60,18 +60,13 @@ struct kmsg_dumper { #ifdef CONFIG_PRINTK void kmsg_dump(enum kmsg_dump_reason reason); -bool kmsg_dump_get_line_nolock(struct kmsg_dumper_iter *iter, bool syslog, - char *line, size_t size, size_t *len); - bool kmsg_dump_get_line(struct kmsg_dumper_iter *iter, bool syslog, char *line, size_t size, size_t *len); bool kmsg_dump_get_buffer(struct kmsg_dumper_iter *iter, bool syslog, char *buf, size_t size, size_t *len_out); -void kmsg_dump_rewind_nolock(struct kmsg_dumper_iter *iter); - -void kmsg_dump_rewind(struct kmsg_dumper_iter *dumper_iter); +void kmsg_dump_rewind(struct kmsg_dumper_iter *iter); int kmsg_dump_register(struct kmsg_dumper *dumper); @@ -83,13 +78,6 @@ static inline void kmsg_dump(enum kmsg_dump_reason reason) { } -static inline bool kmsg_dump_get_line_nolock(struct kmsg_dumper_iter *iter, - bool syslog, const char *line, - size_t size, size_t *len) -{ - return false; -} - static inline bool kmsg_dump_get_line(struct kmsg_dumper_iter *iter, bool syslog, const char *line, size_t size, size_t *len) { @@ -102,10 +90,6 @@ static inline bool kmsg_dump_get_buffer(struct kmsg_dumper_iter *iter, bool sysl return false; } -static inline void kmsg_dump_rewind_nolock(struct kmsg_dumper_iter *iter) -{ -} - static inline void kmsg_dump_rewind(struct kmsg_dumper_iter *iter) { } diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c index 7ae9da245e4b..dbf1d126ac5e 100644 --- a/kernel/debug/kdb/kdb_main.c +++ b/kernel/debug/kdb/kdb_main.c @@ -2126,8 +2126,8 @@ static int kdb_dmesg(int argc, const char **argv) kdb_set(2, setargs); } - kmsg_dump_rewind_nolock(&iter); - while (kmsg_dump_get_line_nolock(&iter, 1, NULL, 0, NULL)) + kmsg_dump_rewind(&iter); + while (kmsg_dump_get_line(&iter, 1, NULL, 0, NULL)) n++; if (lines < 0) { @@ -2159,8 +2159,8 @@ static int kdb_dmesg(int argc, const char **argv) if (skip >= n || skip < 0) return 0; - kmsg_dump_rewind_nolock(&iter); - while (kmsg_dump_get_line_nolock(&iter, 1, buf, sizeof(buf), &len)) { + kmsg_dump_rewind(&iter); + while (kmsg_dump_get_line(&iter, 1, buf, sizeof(buf), &len)) { if (skip) { skip--; continue; diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index c5ea46ed88c7..744b806d5457 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -3378,7 +3378,7 @@ void kmsg_dump(enum kmsg_dump_reason reason) } /** - * kmsg_dump_get_line_nolock - retrieve one kmsg log line (unlocked version) + * kmsg_dump_get_line - retrieve one kmsg log line * @iter: kmsg dumper iterator * @syslog: include the "<4>" prefixes * @line: buffer to copy the line to @@ -3393,18 +3393,18 @@ void kmsg_dump(enum kmsg_dump_reason reason) * * A return value of FALSE indicates that there are no more records to * read. - * - * The function is similar to kmsg_dump_get_line(), but grabs no locks. */ -bool kmsg_dump_get_line_nolock(struct kmsg_dumper_iter *iter, bool syslog, - char *line, size_t size, size_t *len) +bool kmsg_dump_get_line(struct kmsg_dumper_iter *iter, bool syslog, + char *line, size_t size, size_t *len) { struct printk_info info; unsigned int line_count; struct printk_record r; + unsigned long flags; size_t l = 0; bool ret = false; + printk_safe_enter_irqsave(flags); prb_rec_init_rd(&r, &info, line, size); if (!iter->active) @@ -3428,40 +3428,11 @@ bool kmsg_dump_get_line_nolock(struct kmsg_dumper_iter *iter, bool syslog, iter->cur_seq = r.info->seq + 1; ret = true; out: + printk_safe_exit_irqrestore(flags); if (len) *len = l; return ret; } - -/** - * kmsg_dump_get_line - retrieve one kmsg log line - * @iter: kmsg dumper iterator - * @syslog: include the "<4>" prefixes - * @line: buffer to copy the line to - * @size: maximum size of the buffer - * @len: length of line placed into buffer - * - * Start at the beginning of the kmsg buffer, with the oldest kmsg - * record, and copy one record into the provided buffer. - * - * Consecutive calls will return the next available record moving - * towards the end of the buffer with the youngest messages. - * - * A return value of FALSE indicates that there are no more records to - * read. - */ -bool kmsg_dump_get_line(struct kmsg_dumper_iter *iter, bool syslog, - char *line, size_t size, size_t *len) -{ - unsigned long flags; - bool ret; - - printk_safe_enter_irqsave(flags); - ret = kmsg_dump_get_line_nolock(iter, syslog, line, size, len); - printk_safe_exit_irqrestore(flags); - - return ret; -} EXPORT_SYMBOL_GPL(kmsg_dump_get_line); /** @@ -3550,22 +3521,6 @@ bool kmsg_dump_get_buffer(struct kmsg_dumper_iter *iter, bool syslog, } EXPORT_SYMBOL_GPL(kmsg_dump_get_buffer); -/** - * kmsg_dump_rewind_nolock - reset the iterator (unlocked version) - * @iter: kmsg dumper iterator - * - * Reset the dumper's iterator so that kmsg_dump_get_line() and - * kmsg_dump_get_buffer() can be called again and used multiple - * times within the same dumper.dump() callback. - * - * The function is similar to kmsg_dump_rewind(), but grabs no locks. - */ -void kmsg_dump_rewind_nolock(struct kmsg_dumper_iter *iter) -{ - iter->cur_seq = latched_seq_read_nolock(&clear_seq); - iter->next_seq = prb_next_seq(prb); -} - /** * kmsg_dump_rewind - reset the iterator * @iter: kmsg dumper iterator @@ -3579,7 +3534,8 @@ void kmsg_dump_rewind(struct kmsg_dumper_iter *iter) unsigned long flags; printk_safe_enter_irqsave(flags); - kmsg_dump_rewind_nolock(iter); + iter->cur_seq = latched_seq_read_nolock(&clear_seq); + iter->next_seq = prb_next_seq(prb); printk_safe_exit_irqrestore(flags); } EXPORT_SYMBOL_GPL(kmsg_dump_rewind); -- 2.20.1