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Date: Fri, 18 Jul 2014 16:28:04 -0500 From: Alex Elder <elder@...aro.org> To: akpm@...ux-foundation.org Cc: kay@...y.org, pmladek@...e.cz, bp@...e.de, john.stultz@...aro.org, jack@...e.cz, linux-kernel@...r.kernel.org Subject: [PATCH v4 6/7] printk: insert newline for truncated records 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 <pmladek@...e.cz> Signed-off-by: Alex Elder <elder@...aro.org> --- 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@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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