Make the printk output maximum line length globally available.
This can be used to emit logging messages lines that exceed
the single printk maximum length line.
e.g.: the kernel boot command on ARM can be up to 2048 chars
Miscellanea:
o Prefix the defines with PRINTK_
Signed-off-by: Joe Perches <j...@perches.com>
Acked-by: Petr Mladek <pmla...@suse.com>
---
include/linux/printk.h | 18 ++++++++++++++++++
kernel/printk/printk.c | 28 ++++++++++------------------
2 files changed, 28 insertions(+), 18 deletions(-)
diff --git a/include/linux/printk.h b/include/linux/printk.h
index 38beb97e7018..850dc4d4356f 100644
--- a/include/linux/printk.h
+++ b/include/linux/printk.h
@@ -43,6 +43,24 @@ static inline const char *printk_skip_headers(const char
*buffer)
#define CONSOLE_EXT_LOG_MAX 8192
+/* Maximum length of a single printk */
+
+#ifdef CONFIG_PRINTK
+
+#ifdef CONFIG_PRINTK_CALLER
+#define PRINTK_PREFIX_MAX 48
+#else
+#define PRINTK_PREFIX_MAX 32
+#endif
+#define PRINTK_LOG_LINE_MAX (1024 - PRINTK_PREFIX_MAX)
+
+#else
+
+#define PRINTK_PREFIX_MAX 0
+#define PRINTK_LOG_LINE_MAX 0
+
+#endif
+
/* printk's without a loglevel use this.. */
#define MESSAGE_LOGLEVEL_DEFAULT CONFIG_MESSAGE_LOGLEVEL_DEFAULT
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 4f1cc4acef41..fc22a494ef0c 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -443,13 +443,6 @@ static u64 exclusive_console_stop_seq;
static u64 clear_seq;
static u32 clear_idx;
-#ifdef CONFIG_PRINTK_CALLER
-#define PREFIX_MAX 48
-#else
-#define PREFIX_MAX 32
-#endif
-#define LOG_LINE_MAX (1024 - PREFIX_MAX)
-
#define LOG_LEVEL(v) ((v) & 0x07)
#define LOG_FACILITY(v) ((v) >> 3 & 0xff)
@@ -825,7 +818,7 @@ static ssize_t devkmsg_write(struct kiocb *iocb, struct
iov_iter *from)
size_t len = iov_iter_count(from);
ssize_t ret = len;
- if (!user || len > LOG_LINE_MAX)
+ if (!user || len > PRINTK_LOG_LINE_MAX)
return -EINVAL;
/* Ignore when user logging is disabled. */
@@ -1341,7 +1334,7 @@ static size_t msg_print_text(const struct printk_log
*msg, bool syslog,
const char *text = log_text(msg);
size_t text_size = msg->text_len;
size_t len = 0;
- char prefix[PREFIX_MAX];
+ char prefix[PRINTK_PREFIX_MAX];
const size_t prefix_len = print_prefix(msg, syslog, time, prefix);
do {
@@ -1382,7 +1375,7 @@ static int syslog_print(char __user *buf, int size)
struct printk_log *msg;
int len = 0;
- text = kmalloc(LOG_LINE_MAX + PREFIX_MAX, GFP_KERNEL);
+ text = kmalloc(PRINTK_LOG_LINE_MAX + PRINTK_PREFIX_MAX, GFP_KERNEL);
if (!text)
return -ENOMEM;
@@ -1412,7 +1405,7 @@ static int syslog_print(char __user *buf, int size)
skip = syslog_partial;
msg = log_from_idx(syslog_idx);
n = msg_print_text(msg, true, syslog_time, text,
- LOG_LINE_MAX + PREFIX_MAX);
+ PRINTK_LOG_LINE_MAX + PRINTK_PREFIX_MAX);
if (n - syslog_partial <= size) {
/* message fits into buffer, move forward */
syslog_idx = log_next(syslog_idx);
@@ -1454,7 +1447,7 @@ static int syslog_print_all(char __user *buf, int size,
bool clear)
u32 idx;
bool time;
- text = kmalloc(LOG_LINE_MAX + PREFIX_MAX, GFP_KERNEL);
+ text = kmalloc(PRINTK_LOG_LINE_MAX + PRINTK_PREFIX_MAX, GFP_KERNEL);
if (!text)
return -ENOMEM;
@@ -1492,7 +1485,8 @@ static int syslog_print_all(char __user *buf, int size,
bool clear)
while (len >= 0 && seq < next_seq) {
struct printk_log *msg = log_from_idx(idx);
int textlen = msg_print_text(msg, true, time, text,
- LOG_LINE_MAX + PREFIX_MAX);
+ PRINTK_LOG_LINE_MAX +
+ PRINTK_PREFIX_MAX);
idx = log_next(idx);
seq++;
@@ -1845,7 +1839,7 @@ static inline u32 printk_caller_id(void)
* reached the console in case of a kernel crash.
*/
static struct cont {
- char buf[LOG_LINE_MAX];
+ char buf[PRINTK_LOG_LINE_MAX];
size_t len; /* length == 0 means unused buffer */
u32 caller_id; /* printk_caller_id() of first print */
u64 ts_nsec; /* time of first print */
@@ -1931,7 +1925,7 @@ int vprintk_store(int facility, int level,
const char *dict, size_t dictlen,
const char *fmt, va_list args)
{
- static char textbuf[LOG_LINE_MAX];
+ static char textbuf[PRINTK_LOG_LINE_MAX];
char *text = textbuf;
size_t text_len;
enum log_flags lflags = 0;
@@ -2088,8 +2082,6 @@ EXPORT_SYMBOL(printk);
#else /* CONFIG_PRINTK */
-#define LOG_LINE_MAX 0
-#define PREFIX_MAX 0
#define printk_time false
static u64 syslog_seq;
@@ -2396,7 +2388,7 @@ static inline int can_use_console(void)
void console_unlock(void)
{
static char ext_text[CONSOLE_EXT_LOG_MAX];
- static char text[LOG_LINE_MAX + PREFIX_MAX];
+ static char text[PRINTK_LOG_LINE_MAX + PRINTK_PREFIX_MAX];
unsigned long flags;
bool do_cond_resched, retry;
