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-rw-r--r--kernel/printk/printk.c31
1 files changed, 12 insertions, 19 deletions
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index bfbf284e4218..60cdf6386763 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -55,6 +55,7 @@
#include "console_cmdline.h"
#include "braille.h"
+#include "internal.h"
int console_printk[4] = {
CONSOLE_LOGLEVEL_DEFAULT, /* console_loglevel */
@@ -244,7 +245,7 @@ __packed __aligned(4)
* within the scheduler's rq lock. It must be released before calling
* console_unlock() or anything else that might wake up a process.
*/
-static DEFINE_RAW_SPINLOCK(logbuf_lock);
+DEFINE_RAW_SPINLOCK(logbuf_lock);
#ifdef CONFIG_PRINTK
DECLARE_WAIT_QUEUE_HEAD(log_wait);
@@ -1616,6 +1617,7 @@ asmlinkage int vprintk_emit(int facility, int level,
unsigned long flags;
int this_cpu;
int printed_len = 0;
+ int nmi_message_lost;
bool in_sched = false;
/* cpu currently holding logbuf_lock in this function */
static unsigned int logbuf_cpu = UINT_MAX;
@@ -1666,6 +1668,15 @@ asmlinkage int vprintk_emit(int facility, int level,
strlen(recursion_msg));
}
+ nmi_message_lost = get_nmi_message_lost();
+ if (unlikely(nmi_message_lost)) {
+ text_len = scnprintf(textbuf, sizeof(textbuf),
+ "BAD LUCK: lost %d message(s) from NMI context!",
+ nmi_message_lost);
+ printed_len += log_store(0, 2, LOG_PREFIX|LOG_NEWLINE, 0,
+ NULL, 0, textbuf, text_len);
+ }
+
/*
* The printf needs to come first; we need the syslog
* prefix which might be passed-in as a parameter.
@@ -1807,14 +1818,6 @@ int vprintk_default(const char *fmt, va_list args)
}
EXPORT_SYMBOL_GPL(vprintk_default);
-/*
- * This allows printk to be diverted to another function per cpu.
- * This is useful for calling printk functions from within NMI
- * without worrying about race conditions that can lock up the
- * box.
- */
-DEFINE_PER_CPU(printk_func_t, printk_func) = vprintk_default;
-
/**
* printk - print a kernel message
* @fmt: format string
@@ -1838,21 +1841,11 @@ DEFINE_PER_CPU(printk_func_t, printk_func) = vprintk_default;
*/
asmlinkage __visible int printk(const char *fmt, ...)
{
- printk_func_t vprintk_func;
va_list args;
int r;
va_start(args, fmt);
-
- /*
- * If a caller overrides the per_cpu printk_func, then it needs
- * to disable preemption when calling printk(). Otherwise
- * the printk_func should be set to the default. No need to
- * disable preemption here.
- */
- vprintk_func = this_cpu_read(printk_func);
r = vprintk_func(fmt, args);
-
va_end(args);
return r;