lkml.org 
[lkml]   [2012]   [Sep]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] IRQ: Add a check for uninitialized irqs.
On 12-09-09 03:25 PM, raghu.prabhu13@gmail.com wrote:
> From: Raghavendra D Prabhu <rprabhu@wnohang.net>
>
> Errors like "do_IRQ: 0.84 No Irq handler for vector (irq -1)" have been reported
> earlier filling up the console/logs. So this adds a condition to check for

Reported by who, and where, and on what hardware, and under what
circumstances?

You are adding another if statement to the hot path of do_IRQ just
to mask some random unknown symptom. instead of trying to understand
(and then solve) what the real breakage is. Which is not the right
approach.

Paul.
--

> uninitialized irqs so that it exits early and doesn't proceed further. Also, irq
> is made a signed integer, since if it is not mapped to a vector, it will be
> assigned -1 which will be UINT_MAX otherwise.
>
> Signed-off-by: Raghavendra D Prabhu <rprabhu@wnohang.net>
> ---
> arch/x86/kernel/irq.c | 13 ++++++++-----
> 1 file changed, 8 insertions(+), 5 deletions(-)
>
> diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
> index d44f782..ddba63a 100644
> --- a/arch/x86/kernel/irq.c
> +++ b/arch/x86/kernel/irq.c
> @@ -184,21 +184,24 @@ unsigned int __irq_entry do_IRQ(struct pt_regs *regs)
>
> /* high bit used in ret_from_ code */
> unsigned vector = ~regs->orig_ax;
> - unsigned irq;
> + int irq;
>
> irq_enter();
> exit_idle();
>
> - irq = __this_cpu_read(vector_irq[vector]);
> + if (unlikely((irq = __this_cpu_read(vector_irq[vector])) == -1)) {
> + pr_emerg_ratelimited("IRQ handler not setup for vector %u", vector);
> + goto err_exit;
> + }
>
> if (!handle_irq(irq, regs)) {
> ack_APIC_irq();
>
> - if (printk_ratelimit())
> - pr_emerg("%s: %d.%d No irq handler for vector (irq %d)\n",
> - __func__, smp_processor_id(), vector, irq);
> + pr_emerg_ratelimited("%s: %d.%d No irq handler for vector (irq %u)\n",
> + __func__, smp_processor_id(), vector, irq);
> }
>
> +err_exit:
> irq_exit();
>
> set_irq_regs(old_regs);
>


\
 
 \ /
  Last update: 2012-09-10 16:21    [W:0.042 / U:0.700 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site