2020-11-29 14:00:57

by Marc Zyngier

Subject: [PATCH] irqchip/alpine-msi: Fix freeing of interrupts on allocation error path

The alpine-msi driver has an interesting allocation error handling,
where it frees the same interrupts repeatedly. Hilarity follows.

This code is probably never executed, but let's fix it nonetheless.

Fixes: e6b78f2c3e14 ("irqchip: Add the Alpine MSIX interrupt controller")
Cc: Tsahee Zidenberg <[email protected]>
Cc: Antoine Tenart <[email protected]>
Signed-off-by: Marc Zyngier <[email protected]>
---
drivers/irqchip/irq-alpine-msi.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/irqchip/irq-alpine-msi.c b/drivers/irqchip/irq-alpine-msi.c
index 23a3b877f7f1..ede02dc2bcd0 100644
--- a/drivers/irqchip/irq-alpine-msi.c
+++ b/drivers/irqchip/irq-alpine-msi.c
@@ -165,8 +165,7 @@ static int alpine_msix_middle_domain_alloc(struct irq_domain *domain,
return 0;

err_sgi:
- while (--i >= 0)
- irq_domain_free_irqs_parent(domain, virq, i);
+ irq_domain_free_irqs_parent(domain, virq, i - 1);
alpine_msix_free_sgi(priv, sgi, nr_irqs);
return err;
}
--
2.29.2

2020-11-30 09:01:46

by Antoine Tenart

Subject: Re: [PATCH] irqchip/alpine-msi: Fix freeing of interrupts on allocation error path

Hello Marc,

Quoting Marc Zyngier (2020-11-29 14:55:25)
> The alpine-msi driver has an interesting allocation error handling,
> where it frees the same interrupts repeatedly. Hilarity follows.

That's interesting indeed...

> This code is probably never executed, but let's fix it nonetheless.
>
> Fixes: e6b78f2c3e14 ("irqchip: Add the Alpine MSIX interrupt controller")
> Cc: Tsahee Zidenberg <[email protected]>
> Cc: Antoine Tenart <[email protected]>
> Signed-off-by: Marc Zyngier <[email protected]>

Reviewed-by: Antoine Tenart <[email protected]>

Thanks,
Antoine

> ---
> drivers/irqchip/irq-alpine-msi.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/irqchip/irq-alpine-msi.c b/drivers/irqchip/irq-alpine-msi.c
> index 23a3b877f7f1..ede02dc2bcd0 100644
> --- a/drivers/irqchip/irq-alpine-msi.c
> +++ b/drivers/irqchip/irq-alpine-msi.c
> @@ -165,8 +165,7 @@ static int alpine_msix_middle_domain_alloc(struct irq_domain *domain,
> return 0;
>
> err_sgi:
> - while (--i >= 0)
> - irq_domain_free_irqs_parent(domain, virq, i);
> + irq_domain_free_irqs_parent(domain, virq, i - 1);
> alpine_msix_free_sgi(priv, sgi, nr_irqs);
> return err;
> }
> --
> 2.29.2
>

2020-12-11 17:42:23

by tip-bot2 for Dhananjay Ugwekar

Subject: [irqchip: irq/irqchip-next] irqchip/alpine-msi: Fix freeing of interrupts on allocation error path

The following commit has been merged into the irq/irqchip-next branch of irqchip:

Commit-ID: 3841245e8498a789c65dedd7ffa8fb2fee2c0684
Gitweb: https://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms/3841245e8498a789c65dedd7ffa8fb2fee2c0684
Author: Marc Zyngier <[email protected]>
AuthorDate: Sun, 29 Nov 2020 13:55:25
Committer: Marc Zyngier <[email protected]>
CommitterDate: Fri, 11 Dec 2020 14:45:22

irqchip/alpine-msi: Fix freeing of interrupts on allocation error path

The alpine-msi driver has an interesting allocation error handling,
where it frees the same interrupts repeatedly. Hilarity follows.

This code is probably never executed, but let's fix it nonetheless.

Fixes: e6b78f2c3e14 ("irqchip: Add the Alpine MSIX interrupt controller")
Signed-off-by: Marc Zyngier <[email protected]>
Reviewed-by: Antoine Tenart <[email protected]>
Cc: Tsahee Zidenberg <[email protected]>
Cc: Antoine Tenart <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
---
drivers/irqchip/irq-alpine-msi.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/irqchip/irq-alpine-msi.c b/drivers/irqchip/irq-alpine-msi.c
index 23a3b87..ede02dc 100644
--- a/drivers/irqchip/irq-alpine-msi.c
+++ b/drivers/irqchip/irq-alpine-msi.c
@@ -165,8 +165,7 @@ static int alpine_msix_middle_domain_alloc(struct irq_domain *domain,
return 0;

err_sgi:
- while (--i >= 0)
- irq_domain_free_irqs_parent(domain, virq, i);
+ irq_domain_free_irqs_parent(domain, virq, i - 1);
alpine_msix_free_sgi(priv, sgi, nr_irqs);
return err;
}

2020-12-12 13:36:33

by Marc Zyngier

Subject: Re: [PATCH] irqchip/alpine-msi: Fix freeing of interrupts on allocation error path

On Sun, 29 Nov 2020 13:55:25 +0000, Marc Zyngier wrote:
> The alpine-msi driver has an interesting allocation error handling,
> where it frees the same interrupts repeatedly. Hilarity follows.
>
> This code is probably never executed, but let's fix it nonetheless.

Applied to irq/irqchip-next, thanks!

[1/1] irqchip/alpine-msi: Fix freeing of interrupts on allocation error path
commit: 3841245e8498a789c65dedd7ffa8fb2fee2c0684

Cheers,

M.
--
Without deviation from the norm, progress is not possible.