[11/13] irq debug: do not use print_symbol()

Message ID 20171211125025.2270-12-sergey.senozhatsky@gmail.com
State New
Headers show
Series
  • replace print_symbol() with printk()-s
Related show

Commit Message

Sergey Senozhatsky Dec. 11, 2017, 12:50 p.m.
print_symbol() uses extra stack space to sprintf() symbol
information and then to feed that buffer to printk()

  char buffer[KSYM_SYMBOL_LEN];

  sprint_symbol(buffer, address);
  printk(fmt, buffer);

Replace print_symbol() with a direct printk("%pS") call.

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
---
 kernel/irq/debug.h | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

Comments

David Laight Dec. 11, 2017, 12:55 p.m. | #1
From: Sergey Senozhatsky
> Sent: 11 December 2017 12:50
> print_symbol() uses extra stack space to sprintf() symbol
> information and then to feed that buffer to printk()
> 
>   char buffer[KSYM_SYMBOL_LEN];
> 
>   sprint_symbol(buffer, address);
>   printk(fmt, buffer);
> 
> Replace print_symbol() with a direct printk("%pS") call.
> 
> Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> ---
>  kernel/irq/debug.h | 8 +++-----
>  1 file changed, 3 insertions(+), 5 deletions(-)
> 
> diff --git a/kernel/irq/debug.h b/kernel/irq/debug.h
> index 17f05ef8f575..5766e15c1160 100644
> --- a/kernel/irq/debug.h
> +++ b/kernel/irq/debug.h
...
> @@ -15,13 +13,13 @@ static inline void print_irq_desc(unsigned int irq, struct irq_desc *desc)
>  	printk("irq %d, desc: %p, depth: %d, count: %d, unhandled: %d\n",
>  		irq, desc, desc->depth, desc->irq_count, desc->irqs_unhandled);
>  	printk("->handle_irq():  %p, ", desc->handle_irq);
> -	print_symbol("%s\n", (unsigned long)desc->handle_irq);
> +	pr_cont("%pS\n", desc->handle_irq);

Looks like you can (and should) use a single printk() instead of pr_cont.

	David
Sergey Senozhatsky Dec. 12, 2017, 2:50 a.m. | #2
On (12/11/17 12:55), David Laight wrote:
> >  kernel/irq/debug.h | 8 +++-----
> >  1 file changed, 3 insertions(+), 5 deletions(-)
> > 
> > diff --git a/kernel/irq/debug.h b/kernel/irq/debug.h
> > index 17f05ef8f575..5766e15c1160 100644
> > --- a/kernel/irq/debug.h
> > +++ b/kernel/irq/debug.h
> ...
> > @@ -15,13 +13,13 @@ static inline void print_irq_desc(unsigned int irq, struct irq_desc *desc)
> >  	printk("irq %d, desc: %p, depth: %d, count: %d, unhandled: %d\n",
> >  		irq, desc, desc->depth, desc->irq_count, desc->irqs_unhandled);
> >  	printk("->handle_irq():  %p, ", desc->handle_irq);
> > -	print_symbol("%s\n", (unsigned long)desc->handle_irq);
> > +	pr_cont("%pS\n", desc->handle_irq);
> 
> Looks like you can (and should) use a single printk() instead of pr_cont.

thanks, good point. those pr_cont()-s basically just replicate
the old behaviour; but it'll be better to get tid of them. will
follow up shortly.

	-ss

Patch

diff --git a/kernel/irq/debug.h b/kernel/irq/debug.h
index 17f05ef8f575..5766e15c1160 100644
--- a/kernel/irq/debug.h
+++ b/kernel/irq/debug.h
@@ -3,8 +3,6 @@ 
  * Debugging printout:
  */
 
-#include <linux/kallsyms.h>
-
 #define ___P(f) if (desc->status_use_accessors & f) printk("%14s set\n", #f)
 #define ___PS(f) if (desc->istate & f) printk("%14s set\n", #f)
 /* FIXME */
@@ -15,13 +13,13 @@  static inline void print_irq_desc(unsigned int irq, struct irq_desc *desc)
 	printk("irq %d, desc: %p, depth: %d, count: %d, unhandled: %d\n",
 		irq, desc, desc->depth, desc->irq_count, desc->irqs_unhandled);
 	printk("->handle_irq():  %p, ", desc->handle_irq);
-	print_symbol("%s\n", (unsigned long)desc->handle_irq);
+	pr_cont("%pS\n", desc->handle_irq);
 	printk("->irq_data.chip(): %p, ", desc->irq_data.chip);
-	print_symbol("%s\n", (unsigned long)desc->irq_data.chip);
+	pr_cont("%pS\n", desc->irq_data.chip);
 	printk("->action(): %p\n", desc->action);
 	if (desc->action) {
 		printk("->action->handler(): %p, ", desc->action->handler);
-		print_symbol("%s\n", (unsigned long)desc->action->handler);
+		pr_cont("%pS\n", desc->action->handler);
 	}
 
 	___P(IRQ_LEVEL);