diff mbox series

[16/30] mfd: ab8500-debugfs: Remove the racy fiddling with irq_desc

Message ID 20201210194044.157283633@linutronix.de (mailing list archive)
State New, archived
Headers show
Series genirq: Treewide hunt for irq descriptor abuse and assorted fixes | expand

Commit Message

Thomas Gleixner Dec. 10, 2020, 7:25 p.m. UTC
First of all drivers have absolutely no business to dig into the internals
of an irq descriptor. That's core code and subject to change. All of this
information is readily available to /proc/interrupts in a safe and race
free way.

Remove the inspection code which is a blatant violation of subsystem
boundaries and racy against concurrent modifications of the interrupt
descriptor.

Print the irq line instead so the information can be looked up in a sane
way in /proc/interrupts.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: linux-arm-kernel@lists.infradead.org
---
 drivers/mfd/ab8500-debugfs.c |   16 +++-------------
 1 file changed, 3 insertions(+), 13 deletions(-)

Comments

Linus Walleij Dec. 11, 2020, 8:22 a.m. UTC | #1
On Thu, Dec 10, 2020 at 8:42 PM Thomas Gleixner <tglx@linutronix.de> wrote:

> First of all drivers have absolutely no business to dig into the internals
> of an irq descriptor. That's core code and subject to change. All of this
> information is readily available to /proc/interrupts in a safe and race
> free way.
>
> Remove the inspection code which is a blatant violation of subsystem
> boundaries and racy against concurrent modifications of the interrupt
> descriptor.
>
> Print the irq line instead so the information can be looked up in a sane
> way in /proc/interrupts.
>
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> Cc: Linus Walleij <linus.walleij@linaro.org>
> Cc: Lee Jones <lee.jones@linaro.org>
> Cc: linux-arm-kernel@lists.infradead.org

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

Yours,
Linus Walleij
Lee Jones Dec. 11, 2020, 10:04 a.m. UTC | #2
On Thu, 10 Dec 2020, Thomas Gleixner wrote:

> First of all drivers have absolutely no business to dig into the internals
> of an irq descriptor. That's core code and subject to change. All of this
> information is readily available to /proc/interrupts in a safe and race
> free way.
> 
> Remove the inspection code which is a blatant violation of subsystem
> boundaries and racy against concurrent modifications of the interrupt
> descriptor.
> 
> Print the irq line instead so the information can be looked up in a sane
> way in /proc/interrupts.
> 
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> Cc: Linus Walleij <linus.walleij@linaro.org>
> Cc: Lee Jones <lee.jones@linaro.org>
> Cc: linux-arm-kernel@lists.infradead.org
> ---
>  drivers/mfd/ab8500-debugfs.c |   16 +++-------------
>  1 file changed, 3 insertions(+), 13 deletions(-)

Acked-by: Lee Jones <lee.jones@linaro.org>
Andy Shevchenko Dec. 11, 2020, 6:12 p.m. UTC | #3
On Thu, Dec 10, 2020 at 9:57 PM Thomas Gleixner <tglx@linutronix.de> wrote:
>
> First of all drivers have absolutely no business to dig into the internals
> of an irq descriptor. That's core code and subject to change. All of this
> information is readily available to /proc/interrupts in a safe and race
> free way.
>
> Remove the inspection code which is a blatant violation of subsystem
> boundaries and racy against concurrent modifications of the interrupt
> descriptor.
>
> Print the irq line instead so the information can be looked up in a sane
> way in /proc/interrupts.

...

> -               seq_printf(s, "%3i:  %6i %4i",
> +               seq_printf(s, "%3i:  %6i %4i %4i\n",

Seems different specifiers, I think the intention was something like
               seq_printf(s, "%3i:  %4i %6i %4i\n",

>                            line,
> +                          line + irq_first,
>                            num_interrupts[line],
>                            num_wake_interrupts[line]);
diff mbox series

Patch

--- a/drivers/mfd/ab8500-debugfs.c
+++ b/drivers/mfd/ab8500-debugfs.c
@@ -1513,24 +1513,14 @@  static int ab8500_interrupts_show(struct
 {
 	int line;
 
-	seq_puts(s, "name: number:  number of: wake:\n");
+	seq_puts(s, "name: number: irq: number of: wake:\n");
 
 	for (line = 0; line < num_interrupt_lines; line++) {
-		struct irq_desc *desc = irq_to_desc(line + irq_first);
-
-		seq_printf(s, "%3i:  %6i %4i",
+		seq_printf(s, "%3i:  %6i %4i %4i\n",
 			   line,
+			   line + irq_first,
 			   num_interrupts[line],
 			   num_wake_interrupts[line]);
-
-		if (desc && desc->name)
-			seq_printf(s, "-%-8s", desc->name);
-		if (desc && desc->action) {
-			struct irqaction *action = desc->action;
-
-			seq_printf(s, "  %s", action->name);
-			while ((action = action->next) != NULL)
-				seq_printf(s, ", %s", action->name);
 		}
 		seq_putc(s, '\n');
 	}