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Message-Id: <1432557993-20458-7-git-send-email-pmladek@suse.cz>
Date: Mon, 25 May 2015 14:46:29 +0200
From: Petr Mladek <pmladek@...e.cz>
To: Andrew Morton <akpm@...ux-foundation.org>
Cc: Frederic Weisbecker <fweisbec@...il.com>,
Steven Rostedt <rostedt@...dmis.org>,
Dave Anderson <anderson@...hat.com>,
"Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>,
Kay Sievers <kay@...y.org>, Jiri Kosina <jkosina@...e.cz>,
Michal Hocko <mhocko@...e.cz>, Jan Kara <jack@...e.cz>,
linux-kernel@...r.kernel.org, Wang Long <long.wanglong@...wei.com>,
peifeiyue@...wei.com, dzickus@...hat.com, morgan.wang@...wei.com,
sasha.levin@...cle.com, Petr Mladek <pmladek@...e.cz>
Subject: [PATCH 06/10] printk: Split delayed printing of warnings from vprintk_emit()
printk_emit() is too long. Let's split the delayed printing of warnings
into a separate function.
This patch just shuffles the code. There is no change in the functionality.
Signed-off-by: Petr Mladek <pmladek@...e.cz>
---
kernel/printk/printk.c | 64 +++++++++++++++++++++++++++++++-------------------
1 file changed, 40 insertions(+), 24 deletions(-)
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 8fb0aaaa6258..91b8043044ac 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -233,6 +233,9 @@ static DEFINE_RAW_SPINLOCK(logbuf_lock);
DECLARE_WAIT_QUEUE_HEAD(log_wait);
/* cpu currently holding logbuf_lock */
static unsigned int logbuf_cpu = UINT_MAX;
+/* flags used for delayed printing of warnings */
+static int recursion_bug;
+static atomic_t nmi_message_lost;
/* the next printk record to read by syslog(READ) or /proc/kmsg */
static u64 syslog_seq;
static u32 syslog_idx;
@@ -269,6 +272,8 @@ static u32 clear_idx;
static char __log_buf[__LOG_BUF_LEN] __aligned(LOG_ALIGN);
static char *log_buf = __log_buf;
static u32 log_buf_len = __LOG_BUF_LEN;
+/* helper buffer to print formatted text */
+static char textbuf[LOG_LINE_MAX];
/* Return log buffer address */
char *log_buf_addr_get(void)
@@ -1701,13 +1706,44 @@ static int try_logbuf_lock_in_nmi(void)
return 0;
}
+/*
+ * This function modifies the global textbuf and therefore it must be called
+ * under lockbuf_lock!
+ */
+static int vprintk_delayed_warnings(void)
+{
+ int printed_len = 0;
+ int text_len;
+
+ if (unlikely(recursion_bug)) {
+ static const char recursion_msg[] =
+ "BUG: recent printk recursion!";
+
+ recursion_bug = 0;
+ /* emit KERN_CRIT message */
+ printed_len += log_store(0, 2, LOG_PREFIX|LOG_NEWLINE, 0,
+ NULL, 0, recursion_msg,
+ strlen(recursion_msg));
+ }
+
+ if (unlikely(atomic_read(&nmi_message_lost))) {
+ int lost = atomic_xchg(&nmi_message_lost, 0);
+
+ text_len = scnprintf(textbuf, sizeof(textbuf),
+ "BAD LUCK: lost %d message(s) from NMI context!",
+ lost);
+ /* emit KERN_CRIT message */
+ printed_len += log_store(0, 2, LOG_PREFIX|LOG_NEWLINE, 0,
+ NULL, 0, textbuf, text_len);
+ }
+
+ return printed_len;
+}
+
asmlinkage int vprintk_emit(int facility, int level,
const char *dict, size_t dictlen,
const char *fmt, va_list args)
{
- static int recursion_bug;
- static atomic_t nmi_message_lost;
- static char textbuf[LOG_LINE_MAX];
char *text = textbuf;
size_t text_len = 0;
enum log_flags lflags = 0;
@@ -1770,27 +1806,7 @@ asmlinkage int vprintk_emit(int facility, int level,
logbuf_cpu = this_cpu;
- if (unlikely(recursion_bug)) {
- static const char recursion_msg[] =
- "BUG: recent printk recursion!";
-
- recursion_bug = 0;
- /* emit KERN_CRIT message */
- printed_len += log_store(0, 2, LOG_PREFIX|LOG_NEWLINE, 0,
- NULL, 0, recursion_msg,
- strlen(recursion_msg));
- }
-
- if (unlikely(atomic_read(&nmi_message_lost))) {
- int lost = atomic_xchg(&nmi_message_lost, 0);
-
- text_len = scnprintf(text, sizeof(textbuf),
- "BAD LUCK: lost %d message(s) from NMI context!",
- lost);
- /* emit KERN_CRIT message */
- printed_len += log_store(0, 2, LOG_PREFIX|LOG_NEWLINE, 0,
- NULL, 0, text, text_len);
- }
+ printed_len += vprintk_delayed_warnings();
/*
* The printf needs to come first; we need the syslog
--
1.8.5.6
--
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