This is a note to let you know that I've just added the patch titled
kmsg - properly print over-long continuation lines
to my driver-core git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core.git
in the driver-core-next branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will also be merged in the next major kernel release
during the merge window.
If you have any questions about this process, please let me know.
>From 70498253186586e5dca7bc3ebd3415203b059fbc Mon Sep 17 00:00:00 2001
From: Kay Sievers <[email protected]>
Date: Mon, 16 Jul 2012 18:35:29 -0700
Subject: kmsg - properly print over-long continuation lines
Reserve PREFIX_MAX bytes in the LOG_LINE_MAX line when buffering a
continuation line, to be able to properly prefix the LOG_LINE_MAX
line with the syslog prefix and timestamp when printing it.
Reported-By: Dave Jones <[email protected]>
Signed-off-by: Kay Sievers <[email protected]>
Cc: stable <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
kernel/printk.c | 33 +++++++++++++++++++--------------
1 file changed, 19 insertions(+), 14 deletions(-)
diff --git a/kernel/printk.c b/kernel/printk.c
index 177fa49..d87ca5c 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -235,7 +235,8 @@ static u32 log_next_idx;
static u64 clear_seq;
static u32 clear_idx;
-#define LOG_LINE_MAX 1024
+#define PREFIX_MAX 32
+#define LOG_LINE_MAX 1024 - PREFIX_MAX
/* record buffer */
#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
@@ -876,7 +877,7 @@ static size_t msg_print_text(const struct log *msg, enum
log_flags prev,
if (buf) {
if (print_prefix(msg, syslog, NULL) +
- text_len + 1>= size - len)
+ text_len + 1 >= size - len)
break;
if (prefix)
@@ -907,7 +908,7 @@ static int syslog_print(char __user *buf, int size)
struct log *msg;
int len = 0;
- text = kmalloc(LOG_LINE_MAX, GFP_KERNEL);
+ text = kmalloc(LOG_LINE_MAX + PREFIX_MAX, GFP_KERNEL);
if (!text)
return -ENOMEM;
@@ -930,7 +931,8 @@ static int syslog_print(char __user *buf, int size)
skip = syslog_partial;
msg = log_from_idx(syslog_idx);
- n = msg_print_text(msg, syslog_prev, true, text, LOG_LINE_MAX);
+ n = msg_print_text(msg, syslog_prev, true, text,
+ LOG_LINE_MAX + PREFIX_MAX);
if (n - syslog_partial <= size) {
/* message fits into buffer, move forward */
syslog_idx = log_next(syslog_idx);
@@ -969,7 +971,7 @@ static int syslog_print_all(char __user *buf, int size,
bool clear)
char *text;
int len = 0;
- text = kmalloc(LOG_LINE_MAX, GFP_KERNEL);
+ text = kmalloc(LOG_LINE_MAX + PREFIX_MAX, GFP_KERNEL);
if (!text)
return -ENOMEM;
@@ -1022,7 +1024,8 @@ static int syslog_print_all(char __user *buf, int size,
bool clear)
struct log *msg = log_from_idx(idx);
int textlen;
- textlen = msg_print_text(msg, prev, true, text,
LOG_LINE_MAX);
+ textlen = msg_print_text(msg, prev, true, text,
+ LOG_LINE_MAX + PREFIX_MAX);
if (textlen < 0) {
len = textlen;
break;
@@ -1367,15 +1370,15 @@ static struct cont {
bool flushed:1; /* buffer sealed and committed */
} cont;
-static void cont_flush(void)
+static void cont_flush(enum log_flags flags)
{
if (cont.flushed)
return;
if (cont.len == 0)
return;
- log_store(cont.facility, cont.level, LOG_NOCONS, cont.ts_nsec,
- NULL, 0, cont.buf, cont.len);
+ log_store(cont.facility, cont.level, LOG_NOCONS | flags,
+ cont.ts_nsec, NULL, 0, cont.buf, cont.len);
cont.flushed = true;
}
@@ -1386,7 +1389,8 @@ static bool cont_add(int facility, int level, const char
*text, size_t len)
return false;
if (cont.len + len > sizeof(cont.buf)) {
- cont_flush();
+ /* the line gets too long, split it up in separate records */
+ cont_flush(LOG_CONT);
return false;
}
@@ -1522,7 +1526,7 @@ asmlinkage int vprintk_emit(int facility, int level,
* or another task also prints continuation lines.
*/
if (cont.len && (lflags & LOG_PREFIX || cont.owner != current))
- cont_flush();
+ cont_flush(0);
/* buffer line if possible, otherwise store it right away */
if (!cont_add(facility, level, text, text_len))
@@ -1540,7 +1544,7 @@ asmlinkage int vprintk_emit(int facility, int level,
if (cont.len && cont.owner == current) {
if (!(lflags & LOG_PREFIX))
stored = cont_add(facility, level, text,
text_len);
- cont_flush();
+ cont_flush(0);
}
if (!stored)
@@ -1633,7 +1637,8 @@ EXPORT_SYMBOL(printk);
#else
-#define LOG_LINE_MAX 0
+#define LOG_LINE_MAX 0
+#define PREFIX_MAX 0
static struct cont {
size_t len;
size_t cons;
@@ -1938,7 +1943,7 @@ static enum log_flags console_prev;
*/
void console_unlock(void)
{
- static char text[LOG_LINE_MAX];
+ static char text[LOG_LINE_MAX + PREFIX_MAX];
static u64 seen_seq;
unsigned long flags;
bool wake_klogd = false;
--
1.7.10.1.362.g242cab3
--
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