diff -drupN a/kernel/printk/printk.c b/kernel/printk/printk.c
--- a/kernel/printk/printk.c 2018-08-06 17:23:04.000000000 +0300
+++ b/kernel/printk/printk.c 2022-06-12 05:28:14.000000000 +0300
@@ -253,6 +253,17 @@ static int preferred_console = -1;
int console_set_on_cmdline;
EXPORT_SYMBOL(console_set_on_cmdline);
+#ifdef CONFIG_OF
+static bool of_specified_console;
+
+void console_set_by_of(void)
+{
+ of_specified_console = true;
+}
+#else
+# define of_specified_console false
+#endif
+
/* Flag: console code may call schedule() */
static int console_may_schedule;
@@ -655,8 +666,11 @@ static ssize_t msg_print_ext_header(char
* better readable output. 'c' in the record flags mark the first
* fragment of a line, '+' the following.
*/
- if (msg->flags & LOG_CONT)
- cont = (prev_flags & LOG_CONT) ? '+' : 'c';
+ if (msg->flags & LOG_CONT && !(prev_flags & LOG_CONT))
+ cont = 'c';
+ else if ((msg->flags & LOG_CONT) ||
+ ((prev_flags & LOG_CONT) && !(msg->flags & LOG_PREFIX)))
+ cont = '+';
return scnprintf(buf, size, "%u,%llu,%llu,%c;",
(msg->facility << 3) | msg->level, seq, ts_usec, cont);
@@ -1564,7 +1578,7 @@ static void call_console_drivers(int lev
{
struct console *con;
- trace_console_rcuidle(text, len);
+ trace_console(text, len);
if (!console_drivers)
return;
@@ -1640,33 +1654,35 @@ 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;
+
if (cont.cons) {
/*
* If a fragment of this line was directly flushed to the
* console; wait for the console to pick up the rest of the
* line. LOG_NOCONS suppresses a duplicated output.
*/
- log_store(cont.facility, cont.level, cont.flags | LOG_NOCONS,
+ log_store(cont.facility, cont.level, flags | LOG_NOCONS,
cont.ts_nsec, NULL, 0, cont.buf, cont.len);
+ cont.flags = flags;
cont.flushed = true;
} else {
/*
* If no fragment of this line ever reached the console,
* just submit it to the store and free the buffer.
*/
- log_store(cont.facility, cont.level, cont.flags, 0,
+ log_store(cont.facility, cont.level, flags, 0,
NULL, 0, cont.buf, cont.len);
cont.len = 0;
}
}
-static bool cont_add(int facility, int level, enum log_flags flags, const char *text, size_t len)
+static bool cont_add(int facility, int level, const char *text, size_t len)
{
if (cont.len && cont.flushed)
return false;
@@ -1677,7 +1693,7 @@ static bool cont_add(int facility, int l
* the line gets too long, split it up in separate records.
*/
if (nr_ext_console_drivers || cont.len + len > sizeof(cont.buf)) {
- cont_flush();
+ cont_flush(LOG_CONT);
return false;
}
@@ -1686,7 +1702,7 @@ static bool cont_add(int facility, int l
cont.level = level;
cont.owner = current;
cont.ts_nsec = local_clock();
- cont.flags = flags;
+ cont.flags = 0;
cont.cons = 0;
cont.flushed = false;
}
@@ -1694,15 +1710,8 @@ static bool cont_add(int facility, int l
memcpy(cont.buf + cont.len, text, len);
cont.len += len;
- // The original flags come from the first line,
- // but later continuations can add a newline.
- if (flags & LOG_NEWLINE) {
- cont.flags |= LOG_NEWLINE;
- cont_flush();
- }
-
if (cont.len > (sizeof(cont.buf) * 80) / 100)
- cont_flush();
+ cont_flush(LOG_CONT);
return true;
}
@@ -1735,35 +1744,6 @@ static size_t cont_print_text(char *text
return textlen;
}
-static size_t log_output(int facility, int level, enum log_flags lflags, const char *dict, size_t dictlen, char *text, size_t text_len)
-{
- /*
- * If an earlier line was buffered, and we're a continuation
- * write from the same process, try to add it to the buffer.
- */
- if (cont.len) {
- if (cont.owner == current && (lflags & LOG_CONT)) {
- if (cont_add(facility, level, lflags, text, text_len))
- return text_len;
- }
- /* Otherwise, make sure it's flushed */
- cont_flush();
- }
-
- /* Skip empty continuation lines that couldn't be added - they just flush */
- if (!text_len && (lflags & LOG_CONT))
- return 0;
-
- /* If it doesn't end in a newline, try to buffer the current line */
- if (!(lflags & LOG_NEWLINE)) {
- if (cont_add(facility, level, lflags, text, text_len))
- return text_len;
- }
-
- /* Store it in the record log */
- return log_store(facility, level, lflags, 0, dict, dictlen, text, text_len);
-}
-
asmlinkage int vprintk_emit(int facility, int level,
const char *dict, size_t dictlen,
const char *fmt, va_list args)
@@ -1850,9 +1830,10 @@ asmlinkage int vprintk_emit(int facility
/* strip kernel syslog prefix and extract log level or control flags */
if (facility == 0) {
- int kern_level;
+ int kern_level = printk_get_level(text);
- while ((kern_level = printk_get_level(text)) != 0) {
+ if (kern_level) {
+ const char *end_of_header = printk_skip_level(text);
switch (kern_level) {
case '0' ... '7':
if (level == LOGLEVEL_DEFAULT)
@@ -1860,13 +1841,14 @@ asmlinkage int vprintk_emit(int facility
/* fallthrough */
case 'd': /* KERN_DEFAULT */
lflags |= LOG_PREFIX;
- break;
- case 'c': /* KERN_CONT */
- lflags |= LOG_CONT;
}
-
- text_len -= 2;
- text += 2;
+ /*
+ * No need to check length here because vscnprintf
+ * put '\0' at the end of the string. Only valid and
+ * newly printed level is detected.
+ */
+ text_len -= end_of_header - text;
+ text = (char *)end_of_header;
}
}
@@ -1876,7 +1858,45 @@ asmlinkage int vprintk_emit(int facility
if (dict)
lflags |= LOG_PREFIX|LOG_NEWLINE;
- printed_len += log_output(facility, level, lflags, dict, dictlen, text, text_len);
+ if (!(lflags & LOG_NEWLINE)) {
+ /*
+ * Flush the conflicting buffer. An earlier newline was missing,
+ * or another task also prints continuation lines.
+ */
+ if (cont.len && (lflags & LOG_PREFIX || cont.owner != current))
+ cont_flush(LOG_NEWLINE);
+
+ /* buffer line if possible, otherwise store it right away */
+ if (cont_add(facility, level, text, text_len))
+ printed_len += text_len;
+ else
+ printed_len += log_store(facility, level,
+ lflags | LOG_CONT, 0,
+ dict, dictlen, text, text_len);
+ } else {
+ bool stored = false;
+
+ /*
+ * If an earlier newline was missing and it was the same task,
+ * either merge it with the current buffer and flush, or if
+ * there was a race with interrupts (prefix == true) then just
+ * flush it out and store this line separately.
+ * If the preceding printk was from a different task and missed
+ * a newline, flush and append the newline.
+ */
+ if (cont.len) {
+ if (cont.owner == current && !(lflags & LOG_PREFIX))
+ stored = cont_add(facility, level, text,
+ text_len);
+ cont_flush(LOG_NEWLINE);
+ }
+
+ if (stored)
+ printed_len += text_len;
+ else
+ printed_len += log_store(facility, level, lflags, 0,
+ dict, dictlen, text, text_len);
+ }
logbuf_cpu = UINT_MAX;
raw_spin_unlock(&logbuf_lock);
@@ -2642,7 +2662,7 @@ void register_console(struct console *ne
* didn't select a console we take the first one
* that registers here.
*/
- if (preferred_console < 0) {
+ if (preferred_console < 0 && !of_specified_console) {
if (newcon->index < 0)
newcon->index = 0;
if (newcon->setup == NULL ||