[PATCH 1/2] printk: export pr_flush()

From: Martin Hundebøll
Date: Mon Oct 30 2023 - 05:24:55 EST


Printk users might want to assure whatever printed has reached its
destination before continuing. E.g. during the shutdown-procedure, where
printk-buffers aren't necessarily emptied before the system goes down.

Signed-off-by: Martin Hundebøll <martin@xxxxxxxxxx>
---
include/linux/printk.h | 5 +++++
kernel/printk/printk.c | 4 +---
2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/include/linux/printk.h b/include/linux/printk.h
index 8ef499ab3c1e..a2a33494c222 100644
--- a/include/linux/printk.h
+++ b/include/linux/printk.h
@@ -192,6 +192,7 @@ void show_regs_print_info(const char *log_lvl);
extern asmlinkage void dump_stack_lvl(const char *log_lvl) __cold;
extern asmlinkage void dump_stack(void) __cold;
void printk_trigger_flush(void);
+bool pr_flush(int timeout_ms, bool reset_on_progress);
#else
static inline __printf(1, 0)
int vprintk(const char *s, va_list args)
@@ -271,6 +272,10 @@ static inline void dump_stack(void)
static inline void printk_trigger_flush(void)
{
}
+static inline bool pr_flush(int timeout_ms, bool reset_on_progress)
+{
+ return true;
+}
#endif

#ifdef CONFIG_SMP
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 0b3af1529778..dc1d2c880eb0 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -2336,7 +2336,6 @@ asmlinkage __visible int _printk(const char *fmt, ...)
}
EXPORT_SYMBOL(_printk);

-static bool pr_flush(int timeout_ms, bool reset_on_progress);
static bool __pr_flush(struct console *con, int timeout_ms, bool reset_on_progress);

#else /* CONFIG_PRINTK */
@@ -2365,7 +2364,6 @@ static ssize_t msg_print_ext_body(char *buf, size_t size,
static void console_lock_spinning_enable(void) { }
static int console_lock_spinning_disable_and_check(int cookie) { return 0; }
static bool suppress_message_printing(int level) { return false; }
-static bool pr_flush(int timeout_ms, bool reset_on_progress) { return true; }
static bool __pr_flush(struct console *con, int timeout_ms, bool reset_on_progress) { return true; }

#endif /* CONFIG_PRINTK */
@@ -3813,7 +3811,7 @@ static bool __pr_flush(struct console *con, int timeout_ms, bool reset_on_progre
* Context: Process context. May sleep while acquiring console lock.
* Return: true if all usable printers are caught up.
*/
-static bool pr_flush(int timeout_ms, bool reset_on_progress)
+bool pr_flush(int timeout_ms, bool reset_on_progress)
{
return __pr_flush(NULL, timeout_ms, reset_on_progress);
}
--
2.42.0