[PATCH] console_print: change the function api to make it have printk style interface

From: Anirban Sinha
Date: Tue Aug 25 2009 - 19:47:56 EST

Hi Folks:

I bumped into this function in printk.c a while back. As I started using
it, I wondered if we could enhance it with printk style interface that
could make it somewhat more useful.

One straightforward thing to do here would perhaps be to define this as
a macro. Something like this:

#define console_print(fmt,msg...) printk(KERN_EMERG fmt,##msg)

However, there might be some important reason why this was not done. I
do not know.
Anyway, keeping the existing code of using a proper C function and
exporting the symbol, here's a patch that enhances the function to use
prink style interface. To the best of my knowledge, I do not think it
will break existing code that uses this function. I did a grep through
the kernel code and didn't look like this call was used in lot of other
places. I have also built the kernel locally with this change and looks
like at least for mips, it does not break our build.

CCing Linus for his opinion.



Signed-off-by: Anirban Sinha <asinha@xxxxxxxxxxxxxxxxx>
drivers/char/serial167.c | 2 +-
include/linux/tty.h | 2 +-
kernel/printk.c | 14 ++++++++++++--
3 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/drivers/char/serial167.c b/drivers/char/serial167.c
index 51e7a46..029aa0d 100644
--- a/drivers/char/serial167.c
+++ b/drivers/char/serial167.c
@@ -171,7 +171,7 @@ static int startup(struct cyclades_port *);
static void cy_throttle(struct tty_struct *);
static void cy_unthrottle(struct tty_struct *);
static void config_setup(struct cyclades_port *);
-extern void console_print(const char *);
+extern int console_print(const char *, ...);
static void show_status(int);
diff --git a/include/linux/tty.h b/include/linux/tty.h
index e8c6c91..eb3e4fe 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -519,7 +519,7 @@ extern int pcxe_open(struct tty_struct *tty, struct
file *filp);

/* printk.c */

-extern void console_print(const char *);
+extern int console_print(const char *, ...);

/* vt.c */

diff --git a/kernel/printk.c b/kernel/printk.c
index b4d97b5..729b0ff 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -1060,9 +1060,19 @@ void __sched console_conditional_schedule(void)

-void console_print(const char *s)
+int console_print(const char *fmt, ...)
- printk(KERN_EMERG "%s", s);
+ va_list args;
+ int r;
+ char _fmt[1024] = KERN_EMERG;
+ strncat(_fmt, fmt,sizeof(_fmt)- sizeof(KERN_EMERG));
+ va_start(args, fmt);
+ r = vprintk(_fmt, args);
+ va_end(args);
+ return r;


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