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 <pmla...@suse.cz>
Signed-off-by: Alex Elder <el...@linaro.org>
Reviewed-by: Petr Mládek <pmla...@suse.cz>
---
kernel/printk/printk.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index ffc9928..9f11eab 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;
@@ -625,7 +626,10 @@ static ssize_t devkmsg_read(struct file *file, char __user
*buf,
((user->prev & LOG_CONT) && !(msg->flags & LOG_PREFIX)))
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;
@@ -1013,6 +1017,12 @@ static size_t msg_print_text(const struct printk_log
*msg, enum log_flags prev,
newline = false;
}
+ if ((prev & LOG_CONT) && (msg->flags & LOG_PREFIX) && len < size) {
+ if (buf)
+ buf[len++] = '\n';
+ else
+ len++;
+ }
do {
const char *next = memchr(text, '\n', text_size);
size_t text_len;
--
1.9.1
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