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dkim=pass header.d=linutronix.de header.i=@linutronix.de header.a=ed25519-sha256 header.s=2020e header.b=kJjC2HdF; dkim-atps=neutral X-Greylist: delayed 606 seconds by postgrey-1.36 at boromir; Fri, 26 Feb 2021 07:34:57 AEDT Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4Dml012T3Zz3cY8 for ; Fri, 26 Feb 2021 07:34:57 +1100 (AEDT) From: John Ogness DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1614284687; 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=2Gfs86MRR/HIf8qjS9ZT5ZBnpaj1z3IcrEotyUzGR2E=; b=lulIOwnuyU3hd/34KyMUx7ZFGNNdseWIGnmk9oyARB+psVa+gwZ1G9Xq6W1/sETRB0Y0cT 76f/S43QXtg23OwOevaSwfLS9mKZy/VjTO3zsAMrM02VxLZDByEP7jPv5x57ePIKaGQ5kE fqygiDs8QaBDHz9ZmEiTZBBpkDrqZWLviyZDsxNAOBtzCD4TGTUjVLBU4hTAhBzHBJlUqS M2ZMEF50ojDbTEN2iN+JqWDOmeR7DFEL3JpvuXmmObWw7lLWDyiHWO1PB5UWstma0kJBJ7 9cU7tZNaVjcSLJpfZmkFAMES+5hOTrDBAFzM4HvE1PDACj0QVUvnZT7w724Faw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1614284687; 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=2Gfs86MRR/HIf8qjS9ZT5ZBnpaj1z3IcrEotyUzGR2E=; b=kJjC2HdFMTtlJGouQmxH7HQD/YDJ7f3i2SUg/u42twc7gzOZhHLeKKxgP3jL+zaTHIv7Cw daPYXYV4xAlealBw== To: Petr Mladek Subject: [PATCH next v3 14/15] printk: kmsg_dump: remove _nolock() variants Date: Thu, 25 Feb 2021 21:24:37 +0100 Message-Id: <20210225202438.28985-15-john.ogness@linutronix.de> In-Reply-To: <20210225202438.28985-1-john.ogness@linutronix.de> References: <20210225202438.28985-1-john.ogness@linutronix.de> MIME-Version: 1.0 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Sergey Senozhatsky , Douglas Anderson , Paul Mackerras , Kees Cook , Daniel Thompson , Madhavan Srinivasan , Jordan Niethe , Wei Li , Ravi Bangoria , Pavel Tatashin , Alistair Popple , Steven Rostedt , Davidlohr Bueso , Nicholas Piggin , Thomas Gleixner , Sumit Garg , linux-kernel@vger.kernel.org, Sergey Senozhatsky , Jason Wessel , kgdb-bugreport@lists.sourceforge.net, linuxppc-dev@lists.ozlabs.org, Mike Rapoport Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" 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 Reviewed-by: Petr Mladek --- arch/powerpc/xmon/xmon.c | 4 +-- include/linux/kmsg_dump.h | 16 ---------- kernel/debug/kdb/kdb_main.c | 8 ++--- kernel/printk/printk.c | 60 +++++-------------------------------- 4 files changed, 14 insertions(+), 74 deletions(-) diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c index 5978b90a885f..bf7d69625a2e 100644 --- a/arch/powerpc/xmon/xmon.c +++ b/arch/powerpc/xmon/xmon.c @@ -3013,9 +3013,9 @@ 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 5d3bf20f9f0a..532673b6570a 100644 --- a/include/linux/kmsg_dump.h +++ b/include/linux/kmsg_dump.h @@ -57,17 +57,12 @@ struct kmsg_dumper { #ifdef CONFIG_PRINTK void kmsg_dump(enum kmsg_dump_reason reason); -bool kmsg_dump_get_line_nolock(struct kmsg_dump_iter *iter, bool syslog, - char *line, size_t size, size_t *len); - bool kmsg_dump_get_line(struct kmsg_dump_iter *iter, bool syslog, char *line, size_t size, size_t *len); bool kmsg_dump_get_buffer(struct kmsg_dump_iter *iter, bool syslog, char *buf, size_t size, size_t *len_out); -void kmsg_dump_rewind_nolock(struct kmsg_dump_iter *iter); - void kmsg_dump_rewind(struct kmsg_dump_iter *iter); int kmsg_dump_register(struct kmsg_dumper *dumper); @@ -80,13 +75,6 @@ static inline void kmsg_dump(enum kmsg_dump_reason reason) { } -static inline bool kmsg_dump_get_line_nolock(struct kmsg_dump_iter *iter, - bool syslog, const char *line, - size_t size, size_t *len) -{ - return false; -} - static inline bool kmsg_dump_get_line(struct kmsg_dump_iter *iter, bool syslog, const char *line, size_t size, size_t *len) { @@ -99,10 +87,6 @@ static inline bool kmsg_dump_get_buffer(struct kmsg_dump_iter *iter, bool syslog return false; } -static inline void kmsg_dump_rewind_nolock(struct kmsg_dump_iter *iter) -{ -} - static inline void kmsg_dump_rewind(struct kmsg_dump_iter *iter) { } diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c index 8544d7a55a57..67d9f2403b52 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 01385ea92e7c..15a9bc409e0a 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -3373,7 +3373,7 @@ 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 dump iterator * @syslog: include the "<4>" prefixes * @line: buffer to copy the line to @@ -3388,18 +3388,18 @@ 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_dump_iter *iter, bool syslog, - char *line, size_t size, size_t *len) +bool kmsg_dump_get_line(struct kmsg_dump_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); /* Read text or count text lines? */ @@ -3420,40 +3420,11 @@ bool kmsg_dump_get_line_nolock(struct kmsg_dump_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 dump 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_dump_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); /** @@ -3542,22 +3513,6 @@ bool kmsg_dump_get_buffer(struct kmsg_dump_iter *iter, bool syslog, } EXPORT_SYMBOL_GPL(kmsg_dump_get_buffer); -/** - * kmsg_dump_rewind_nolock - reset the iterator (unlocked version) - * @iter: kmsg dump 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_dump_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 dump iterator @@ -3571,7 +3526,8 @@ void kmsg_dump_rewind(struct kmsg_dump_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);