From patchwork Wed Sep 4 13:46:05 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?b?SsO8cmdlbiBHcm/Dnw==?= X-Patchwork-Id: 11130325 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id EEF041395 for ; Wed, 4 Sep 2019 13:47:33 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id D3A7A2339D for ; Wed, 4 Sep 2019 13:47:33 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D3A7A2339D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1i5Vc3-0003nR-Tc; Wed, 04 Sep 2019 13:46:19 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1i5Vc2-0003n7-Hn for xen-devel@lists.xenproject.org; Wed, 04 Sep 2019 13:46:18 +0000 X-Inumbo-ID: 5b2cbb38-cf1a-11e9-a337-bc764e2007e4 Received: from mx1.suse.de (unknown [195.135.220.15]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 5b2cbb38-cf1a-11e9-a337-bc764e2007e4; Wed, 04 Sep 2019 13:46:12 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 3A111AEEE; Wed, 4 Sep 2019 13:46:11 +0000 (UTC) From: Juergen Gross To: xen-devel@lists.xenproject.org Date: Wed, 4 Sep 2019 15:46:05 +0200 Message-Id: <20190904134608.18425-2-jgross@suse.com> X-Mailer: git-send-email 2.16.4 In-Reply-To: <20190904134608.18425-1-jgross@suse.com> References: <20190904134608.18425-1-jgross@suse.com> Subject: [Xen-devel] [PATCH v4 1/4] xen: fix debugtrace clearing X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Juergen Gross , Stefano Stabellini , Wei Liu , Konrad Rzeszutek Wilk , George Dunlap , Andrew Cooper , Ian Jackson , Tim Deegan , Julien Grall , Jan Beulich MIME-Version: 1.0 Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" After dumping the debugtrace buffer it is cleared. This results in some entries not being printed in case the buffer is dumped again before having wrapped. While at it remove the trailing zero byte in the buffer as it is no longer needed. Commit b5e6e1ee8da59f introduced passing the number of chars to be printed in the related interfaces, so the trailing 0 byte is no longer required. Signed-off-by: Juergen Gross --- xen/drivers/char/console.c | 17 ++++++++--------- 1 file changed, 8 insertions(+), 9 deletions(-) diff --git a/xen/drivers/char/console.c b/xen/drivers/char/console.c index f49c6f29a8..62477a9728 100644 --- a/xen/drivers/char/console.c +++ b/xen/drivers/char/console.c @@ -1171,6 +1171,7 @@ static volatile int debugtrace_send_to_console; static char *debugtrace_buf; /* Debug-trace buffer */ static unsigned int debugtrace_prd; /* Producer index */ +static unsigned int debugtrace_prd_last; static unsigned int debugtrace_kilobytes = 128, debugtrace_bytes; static unsigned int debugtrace_used; static DEFINE_SPINLOCK(debugtrace_lock); @@ -1184,16 +1185,17 @@ static void debugtrace_dump_worker(void) printk("debugtrace_dump() starting\n"); /* Print oldest portion of the ring. */ - ASSERT(debugtrace_buf[debugtrace_bytes - 1] == 0); if ( debugtrace_buf[debugtrace_prd] != '\0' ) console_serial_puts(&debugtrace_buf[debugtrace_prd], - debugtrace_bytes - debugtrace_prd - 1); + debugtrace_bytes - debugtrace_prd); /* Print youngest portion of the ring. */ debugtrace_buf[debugtrace_prd] = '\0'; console_serial_puts(&debugtrace_buf[0], debugtrace_prd); memset(debugtrace_buf, '\0', debugtrace_bytes); + debugtrace_prd = 0; + debugtrace_prd_last = 0; printk("debugtrace_dump() finished\n"); } @@ -1241,8 +1243,7 @@ static void debugtrace_add_to_buf(char *buf) for ( p = buf; *p != '\0'; p++ ) { debugtrace_buf[debugtrace_prd++] = *p; - /* Always leave a nul byte at the end of the buffer. */ - if ( debugtrace_prd == (debugtrace_bytes - 1) ) + if ( debugtrace_prd == debugtrace_bytes ) debugtrace_prd = 0; } } @@ -1250,7 +1251,7 @@ static void debugtrace_add_to_buf(char *buf) void debugtrace_printk(const char *fmt, ...) { static char buf[1024], last_buf[1024]; - static unsigned int count, last_count, last_prd; + static unsigned int count, last_count; char cntbuf[24]; va_list args; @@ -1264,8 +1265,6 @@ void debugtrace_printk(const char *fmt, ...) spin_lock_irqsave(&debugtrace_lock, flags); - ASSERT(debugtrace_buf[debugtrace_bytes - 1] == 0); - va_start(args, fmt); nr = vscnprintf(buf, sizeof(buf), fmt, args); va_end(args); @@ -1281,14 +1280,14 @@ void debugtrace_printk(const char *fmt, ...) { if ( strcmp(buf, last_buf) ) { - last_prd = debugtrace_prd; + debugtrace_prd_last = debugtrace_prd; last_count = ++count; safe_strcpy(last_buf, buf); snprintf(cntbuf, sizeof(cntbuf), "%u ", count); } else { - debugtrace_prd = last_prd; + debugtrace_prd = debugtrace_prd_last; snprintf(cntbuf, sizeof(cntbuf), "%u-%u ", last_count, ++count); } debugtrace_add_to_buf(cntbuf);