[RFC 1/8] printk: move code regarding log message storing format

Marcin Niesluchowski
2015-07-03T10:50:27Z

Preparation commit for future changes purpose.

Moves some code responsible for storing log messages in proper format.

Signed-off-by: Marcin Niesluchowski <m.niesluchow@samsung.com>
---
kernel/printk/printk.c | 254 ++++++++++++++++++++++++-------------------------
1 file changed, 127 insertions(+), 127 deletions(-)

diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index cf8c242..98f5af5 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -475,6 +475,133 @@ static int log_store(int facility, int level,
return msg->text_len;
}

+static bool printk_time = IS_ENABLED(CONFIG_PRINTK_TIME);
+module_param_named(time, printk_time, bool, S_IRUGO | S_IWUSR);
+
+static size_t print_time(u64 ts, char *buf)
+{
+ unsigned long rem_nsec;
+
+ if (!printk_time)
+ return 0;
+
+ rem_nsec = do_div(ts, 1000000000);
+
+ if (!buf)
+ return snprintf(NULL, 0, "[%5lu.000000] ", (unsigned long)ts);
+
+ return sprintf(buf, "[%5lu.%06lu] ",
+ (unsigned long)ts, rem_nsec / 1000);
+}
+
+/*
+ * Continuation lines are buffered, and not committed to the record buffer
+ * until the line is complete, or a race forces it. The line fragments
+ * though, are printed immediately to the consoles to ensure everything has
+ * reached the console in case of a kernel crash.
+ */
+static struct cont {
+ char buf[LOG_LINE_MAX];
+ size_t len; /* length == 0 means unused buffer */
+ size_t cons; /* bytes written to console */
+ struct task_struct *owner; /* task of first print*/
+ u64 ts_nsec; /* time of first print */
+ u8 level; /* log level of first message */
+ u8 facility; /* log facility of first message */
+ enum log_flags flags; /* prefix, newline flags */
+ bool flushed:1; /* buffer sealed and committed */
+} cont;
+
+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, 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, flags, 0,
+ NULL, 0, cont.buf, cont.len);
+ cont.len = 0;
+ }
+}
+
+static bool cont_add(int facility, int level, const char *text, size_t len)
+{
+ if (cont.len && cont.flushed)
+ return false;
+
+ /*
+ * If ext consoles are present, flush and skip in-kernel
+ * continuation. See nr_ext_console_drivers definition. Also, if
+ * the line gets too long, split it up in separate records.
+ */
+ if (nr_ext_console_drivers || cont.len + len > sizeof(cont.buf)) {
+ cont_flush(LOG_CONT);
+ return false;
+ }
+
+ if (!cont.len) {
+ cont.facility = facility;
+ cont.level = level;
+ cont.owner = current;
+ cont.ts_nsec = local_clock();
+ cont.flags = 0;
+ cont.cons = 0;
+ cont.flushed = false;
+ }
+
+ memcpy(cont.buf + cont.len, text, len);
+ cont.len += len;
+
+ if (cont.len > (sizeof(cont.buf) * 80) / 100)
+ cont_flush(LOG_CONT);
+
+ return true;
+}
+
+static size_t cont_print_text(char *text, size_t size)
+{
+ size_t textlen = 0;
+ size_t len;
+
+ if (cont.cons == 0 && (console_prev & LOG_NEWLINE)) {
+ textlen += print_time(cont.ts_nsec, text);
+ size -= textlen;
+ }
+
+ len = cont.len - cont.cons;
+ if (len > 0) {
+ if (len+1 > size)
+ len = size-1;
+ memcpy(text + textlen, cont.buf + cont.cons, len);
+ textlen += len;
+ cont.cons = cont.len;
+ }
+
+ if (cont.flushed) {
+ if (cont.flags & LOG_NEWLINE)
+ text[textlen++] = '\n';
+ /* got everything, release buffer */
+ cont.len = 0;
+ }
+ return textlen;
+}
+
int dmesg_restrict = IS_ENABLED(CONFIG_SECURITY_DMESG_RESTRICT);

static int syslog_action_restricted(int type)
@@ -1030,25 +1157,6 @@ static inline void boot_delay_msec(int level)
}
#endif

-static bool printk_time = IS_ENABLED(CONFIG_PRINTK_TIME);
-module_param_named(time, printk_time, bool, S_IRUGO | S_IWUSR);
-
-static size_t print_time(u64 ts, char *buf)
-{
- unsigned long rem_nsec;
-
- if (!printk_time)
- return 0;
-
- rem_nsec = do_div(ts, 1000000000);
-
- if (!buf)
- return snprintf(NULL, 0, "[%5lu.000000] ", (unsigned long)ts);
-
- return sprintf(buf, "[%5lu.%06lu] ",
- (unsigned long)ts, rem_nsec / 1000);
-}
-
static size_t print_prefix(const struct printk_log *msg, bool syslog, char *buf)
{
size_t len = 0;
@@ -1544,114 +1652,6 @@ static inline void printk_delay(void)
}
}

-/*
- * Continuation lines are buffered, and not committed to the record buffer
- * until the line is complete, or a race forces it. The line fragments
- * though, are printed immediately to the consoles to ensure everything has
- * reached the console in case of a kernel crash.
- */
-static struct cont {
- char buf[LOG_LINE_MAX];
- size_t len; /* length == 0 means unused buffer */
- size_t cons; /* bytes written to console */
- struct task_struct *owner; /* task of first print*/
- u64 ts_nsec; /* time of first print */
- u8 level; /* log level of first message */
- u8 facility; /* log facility of first message */
- enum log_flags flags; /* prefix, newline flags */
- bool flushed:1; /* buffer sealed and committed */
-} cont;
-
-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, 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, flags, 0,
- NULL, 0, cont.buf, cont.len);
- cont.len = 0;
- }
-}
-
-static bool cont_add(int facility, int level, const char *text, size_t len)
-{
- if (cont.len && cont.flushed)
- return false;
-
- /*
- * If ext consoles are present, flush and skip in-kernel
- * continuation. See nr_ext_console_drivers definition. Also, if
- * the line gets too long, split it up in separate records.
- */
- if (nr_ext_console_drivers || cont.len + len > sizeof(cont.buf)) {
- cont_flush(LOG_CONT);
- return false;
- }
-
- if (!cont.len) {
- cont.facility = facility;
- cont.level = level;
- cont.owner = current;
- cont.ts_nsec = local_clock();
- cont.flags = 0;
- cont.cons = 0;
- cont.flushed = false;
- }
-
- memcpy(cont.buf + cont.len, text, len);
- cont.len += len;
-
- if (cont.len > (sizeof(cont.buf) * 80) / 100)
- cont_flush(LOG_CONT);
-
- return true;
-}
-
-static size_t cont_print_text(char *text, size_t size)
-{
- size_t textlen = 0;
- size_t len;
-
- if (cont.cons == 0 && (console_prev & LOG_NEWLINE)) {
- textlen += print_time(cont.ts_nsec, text);
- size -= textlen;
- }
-
- len = cont.len - cont.cons;
- if (len > 0) {
- if (len+1 > size)
- len = size-1;
- memcpy(text + textlen, cont.buf + cont.cons, len);
- textlen += len;
- cont.cons = cont.len;
- }
-
- if (cont.flushed) {
- if (cont.flags & LOG_NEWLINE)
- text[textlen++] = '\n';
- /* got everything, release buffer */
- cont.len = 0;
- }
- return textlen;
-}
-
asmlinkage int vprintk_emit(int facility, int level,
const char *dict, size_t dictlen,
const char *fmt, va_list args)
--
1.9.1