Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935324AbaGRV2o (ORCPT ); Fri, 18 Jul 2014 17:28:44 -0400 Received: from mail-ie0-f180.google.com ([209.85.223.180]:58310 "EHLO mail-ie0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1946107AbaGRV2P (ORCPT ); Fri, 18 Jul 2014 17:28:15 -0400 From: Alex Elder To: akpm@linux-foundation.org Cc: kay@vrfy.org, pmladek@suse.cz, bp@suse.de, john.stultz@linaro.org, jack@suse.cz, linux-kernel@vger.kernel.org Subject: [PATCH v4 6/7] printk: insert newline for truncated records Date: Fri, 18 Jul 2014 16:28:04 -0500 Message-Id: <1405718885-11227-7-git-send-email-elder@linaro.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1405718885-11227-1-git-send-email-elder@linaro.org> References: <1405718885-11227-1-git-send-email-elder@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org If a log record has LOG_PREFIX set, its predecessor record should be terminated if it was marked LOG_CONT. In devkmsg_read(), this condition was being ignored, which would lead to such records showing up combined when reading /dev/kmsg. Fix this oversight. We should similarly insert a newline in msg_print_text() in this case, to avoid formatted records getting merged. Suggested-by: Petr Mládek Signed-off-by: Alex Elder --- kernel/printk/printk.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index e9f0632..a5ad81c 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -575,6 +575,7 @@ static ssize_t devkmsg_read(struct file *file, char __user *buf, char cont; size_t len; ssize_t ret; + bool insert_newline; if (!user) return -EBADF; @@ -626,7 +627,10 @@ static ssize_t devkmsg_read(struct file *file, char __user *buf, else cont = '-'; - len = sprintf(user->buf, "%u,%llu,%llu,%c;", + /* Insert a newline if the previous line was not terminated properly */ + insert_newline = (user->prev & LOG_CONT) && (msg->flags & LOG_PREFIX); + len = sprintf(user->buf, "%s%u,%llu,%llu,%c;", + insert_newline ? "\n" : "", (msg->facility << 3) | msg->level, user->seq, ts_usec, cont); user->prev = msg->flags; @@ -999,10 +1003,12 @@ static size_t msg_print_text(const struct printk_log *msg, enum log_flags prev, { const char *text = log_text(msg); size_t text_size = msg->text_len; + size_t len = 0; + bool insert_newline; bool prefix = true; bool newline = true; - size_t len = 0; + insert_newline = (prev & LOG_CONT) && (msg->flags & LOG_PREFIX); if ((prev & LOG_CONT) && !(msg->flags & LOG_PREFIX)) prefix = false; @@ -1023,9 +1029,13 @@ static size_t msg_print_text(const struct printk_log *msg, enum log_flags prev, if (buf) { if (print_prefix(msg, syslog, NULL) + - text_len + 1 >= size - len) + text_len + 2 >= size - len) break; + if (insert_newline) { + insert_newline = false; + buf[len++] = '\n'; + } if (prefix) len += print_prefix(msg, syslog, buf + len); memcpy(buf + len, text, text_len); @@ -1034,6 +1044,8 @@ static size_t msg_print_text(const struct printk_log *msg, enum log_flags prev, buf[len++] = '\n'; } else { /* SYSLOG_ACTION_* buffer size only calculation */ + if (insert_newline) + len++; if (prefix) len += print_prefix(msg, syslog, NULL); len += text_len; -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/