From mboxrd@z Thu Jan 1 00:00:00 1970 Delivery-date: Fri, 17 Oct 2025 13:05:17 +0200 Received: from metis.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::104]) by lore.white.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1v9iGr-008nYQ-2s for lore@lore.pengutronix.de; Fri, 17 Oct 2025 13:05:17 +0200 Received: from bombadil.infradead.org ([2607:7c80:54:3::133]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1v9iGr-0003Eh-86 for lore@pengutronix.de; Fri, 17 Oct 2025 13:05:17 +0200 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Cc:To:Message-Id: Content-Transfer-Encoding:Content-Type:MIME-Version:Subject:Date:From: Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender :Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References:List-Owner; bh=4UtRIyYaVPMdmWl7i6NbmR6AfSZ+in6yptkzIBPgZyQ=; b=VUONkEZFrImY2fvfID5fnUh4aT bYws6lW3kFbNc+c3R+MMg5juG1qmxl7m5frlMd9V6bwbilzuDNV5502KEBflRg+g47aKIZ8QwQksF MAz3t+BIuZSoDCUea7sieuHEswL5SZepPB3sQrH1dmBuKAJbXx/Tkiog5rDFyQzMi3sZUnd2WaJPh 1byBV4wc1MZ6+TgEcZA8ZHSPomClrebYCjixHGNzt55OYJ+wt4smzWa2cZRy47r61L5tHJLGpowmT nFyl507K+inMbPxZ+bb5EdnR4q734wXoaCcYLBWT8xsPMje8iNV4ZB6McIoXTtOoVTsXeHMES5jKC c7akXLkQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1v9iGN-00000007cU0-1U9g; Fri, 17 Oct 2025 11:04:47 +0000 Received: from metis.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::104]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1v9iGK-00000007cTZ-48F3 for barebox@lists.infradead.org; Fri, 17 Oct 2025 11:04:46 +0000 Received: from dude04.red.stw.pengutronix.de ([2a0a:edc0:0:1101:1d::ac]) by metis.whiteo.stw.pengutronix.de with esmtp (Exim 4.92) (envelope-from ) id 1v9iGI-00037p-Lt; Fri, 17 Oct 2025 13:04:42 +0200 From: Jonas Rebmann Date: Fri, 17 Oct 2025 13:04:36 +0200 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20251017-dmesg-v1-1-ac9c2fb021f6@pengutronix.de> X-B4-Tracking: v=1; b=H4sIAMMi8mgC/6tWKk4tykwtVrJSqFYqSi3LLM7MzwNyDHUUlJIzE vPSU3UzU4B8JSMDI1NDA0Nz3ZTc1OJ0XQPTJMtUEzOjVItEQyWg2oKi1LTMCrA50bG1tQC2PNv yVwAAAA== X-Change-ID: 20251017-dmesg-05b9e462e8a1 To: Sascha Hauer , BAREBOX Cc: Jonas Rebmann X-Mailer: b4 0.15-dev-7abec X-Developer-Signature: v=1; a=openpgp-sha256; l=3831; i=jre@pengutronix.de; h=from:subject:message-id; bh=lcMbuzOR5Xroi//bxQGiydaeSpMS78EvzXZ+0FAdFXI=; b=owGbwMvMwCV2ZcYT3onnbjcwnlZLYsj4pHRk4qqKjcnPJlRnZ5ydsUR3/t8Gljfya7/zMlw9d cHppoXTzY5SFgYxLgZZMUWWWDU5BSFj/+tmlXaxMHNYmUCGMHBxCsBElr9m+J/O31zvGvrlRvmF 9qffkpqXX9a9rXNeIrjQ9+lVVm15p4MM//MM3WbdzvVT9ymbL1pzNetI0aEdRU6yxsvlTWY9O8W cxAEA X-Developer-Key: i=jre@pengutronix.de; a=openpgp; fpr=0B7B750D5D3CD21B3B130DE8B61515E135CD49B5 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20251017_040445_026823_47C7A693 X-CRM114-Status: GOOD ( 18.72 ) X-BeenThere: barebox@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "barebox" X-SA-Exim-Connect-IP: 2607:7c80:54:3::133 X-SA-Exim-Mail-From: barebox-bounces+lore=pengutronix.de@lists.infradead.org X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on metis.whiteo.stw.pengutronix.de X-Spam-Level: X-Spam-Status: No, score=-3.5 required=4.0 tests=AWL,BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_NONE autolearn=unavailable autolearn_force=no version=3.4.2 Subject: [PATCH] commands: dmesg: clear logbuffer fully if not requested otherwise X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on metis.whiteo.stw.pengutronix.de) Previously, `dmesg -c` would clear the logbuffer except for the last 10 lines. This comes with a fair amount of surprise given linux `dmesg -c` clears the whole logbuffer. Clear the complete logbuffer given `dmesg -c` but with an optional argument `dmesg -c []` to keep lines. While at it, move the deleteion of log lines to the log_print function to prevent a corner case of lost log message if they arrive between the log_print() and log_clean() in dmesg. If loglevels are selected using -l or -p in addition to cleaning being selected using -c, only clean those messages shown by the loglevel selection. Signed-off-by: Jonas Rebmann --- commands/dmesg.c | 17 ++++++++++------- common/console_common.c | 20 +++++++++++++++++--- include/linux/printk.h | 2 +- 3 files changed, 28 insertions(+), 11 deletions(-) diff --git a/commands/dmesg.c b/commands/dmesg.c index a93ad5b359..6853f3afc9 100644 --- a/commands/dmesg.c +++ b/commands/dmesg.c @@ -77,14 +77,20 @@ static unsigned dmesg_get_levels(const char *__args) static int do_dmesg(int argc, char *argv[]) { int opt, ret, i; - int delete_buf = 0, emit = 0; + int delete_buf = -1, emit = 0; unsigned flags = 0, levels = 0; char *set = NULL; - while ((opt = getopt(argc, argv, "ctderl:p:n:")) > 0) { + while ((opt = getopt(argc, argv, "c::tderl:p:n:")) > 0) { switch (opt) { case 'c': - delete_buf = 1; + if (optarg) { + ret = kstrtoint(optarg, 10, &delete_buf); + if (ret || delete_buf < 0) + return COMMAND_ERROR_USAGE; + } else { + delete_buf = 0; + } break; case 't': flags |= BAREBOX_LOG_PRINT_TIME; @@ -155,13 +161,10 @@ static int do_dmesg(int argc, char *argv[]) return 0; } - ret = log_print(flags, levels); + ret = log_print(flags, levels, delete_buf); if (ret) return 1; - if (delete_buf) - log_clean(10); - return 0; } diff --git a/common/console_common.c b/common/console_common.c index 5b7a64c99c..23646d8f81 100644 --- a/common/console_common.c +++ b/common/console_common.c @@ -210,12 +210,23 @@ int log_writefile(const char *filepath) return ret < 0 ? ret : nbytes; } -int log_print(unsigned flags, unsigned levels) +/** + * log_print - print and optionally clear the log buffer + * + * @flags: Flags selecting output formatting + * @levels: bitmask of loglevels to print, 0 for all + * @delete_buf: Number of printed lines to keep in the buffer, + * -1 to keep all. + * + * This function deletes all messages in the logbuf exceeding + * the limit. + */ +int log_print(unsigned flags, unsigned levels, int delete_buf) { - struct log_entry *log; + struct log_entry *log, *tmp; unsigned long last = 0; - list_for_each_entry(log, &barebox_logbuf, list) { + list_for_each_entry_safe(log, tmp, &barebox_logbuf, list) { uint64_t time_ns = log->timestamp; unsigned long time; @@ -250,6 +261,9 @@ int log_print(unsigned flags, unsigned levels) printf("] "); printf("%s", log->msg); + + if (delete_buf >= 0 && barebox_logbuf_num_messages > delete_buf) + log_del(log); } return 0; diff --git a/include/linux/printk.h b/include/linux/printk.h index 0d7180f0eb..78ab3e6d16 100644 --- a/include/linux/printk.h +++ b/include/linux/printk.h @@ -192,7 +192,7 @@ extern void log_clean(unsigned int limit); #define BAREBOX_LOG_PRINT_TIME BIT(0) int log_writefile(const char *filepath); -int log_print(unsigned flags, unsigned levels); +int log_print(unsigned flags, unsigned levels, int delete_buf); struct va_format { const char *fmt; --- base-commit: 8defba1d0ab1aef9dd5d57710e18d0d02e2c48e2 change-id: 20251017-dmesg-05b9e462e8a1 Best regards, -- Jonas Rebmann