From: "Jürgen Groß" <jgross@suse.com>
To: stable@vger.kernel.org
Cc: Stefan Bader <stefan.bader@canonical.com>,
Boris Ostrovsky <boris.ostrovsky@oracle.com>
Subject: Re: [PATCH] xen/events: don't use chip_data for legacy IRQs
Date: Wed, 14 Oct 2020 11:31:33 +0200 [thread overview]
Message-ID: <f0b0b56e-512a-84ed-f03f-86ef54c10e96@suse.com> (raw)
In-Reply-To: <20201005061957.13509-1-jgross@suse.com>
Any reason this has not made it into 5.4.y and older by now?
This patch is fixing a real problem...
Juergen
On 05.10.20 08:19, Juergen Gross wrote:
> Since commit c330fb1ddc0a ("XEN uses irqdesc::irq_data_common::handler_data to store a per interrupt XEN data pointer which contains XEN specific information.")
> Xen is using the chip_data pointer for storing IRQ specific data. When
> running as a HVM domain this can result in problems for legacy IRQs, as
> those might use chip_data for their own purposes.
>
> Use a local array for this purpose in case of legacy IRQs, avoiding the
> double use.
>
> Fixes: c330fb1ddc0a ("XEN uses irqdesc::irq_data_common::handler_data to store a per interrupt XEN data pointer which contains XEN specific information.")
> Signed-off-by: Juergen Gross <jgross@suse.com>
> Tested-by: Stefan Bader <stefan.bader@canonical.com>
> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
> Link: https://lore.kernel.org/r/20200930091614.13660-1-jgross@suse.com
> ---
> This is a backport for stable kernel 5.4.y and older
> ---
> drivers/xen/events/events_base.c | 29 +++++++++++++++++++++--------
> 1 file changed, 21 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c
> index 55f2b834cf13..e402620b8920 100644
> --- a/drivers/xen/events/events_base.c
> +++ b/drivers/xen/events/events_base.c
> @@ -91,6 +91,8 @@ static bool (*pirq_needs_eoi)(unsigned irq);
> /* Xen will never allocate port zero for any purpose. */
> #define VALID_EVTCHN(chn) ((chn) != 0)
>
> +static struct irq_info *legacy_info_ptrs[NR_IRQS_LEGACY];
> +
> static struct irq_chip xen_dynamic_chip;
> static struct irq_chip xen_percpu_chip;
> static struct irq_chip xen_pirq_chip;
> @@ -155,7 +157,18 @@ int get_evtchn_to_irq(unsigned evtchn)
> /* Get info for IRQ */
> struct irq_info *info_for_irq(unsigned irq)
> {
> - return irq_get_chip_data(irq);
> + if (irq < nr_legacy_irqs())
> + return legacy_info_ptrs[irq];
> + else
> + return irq_get_chip_data(irq);
> +}
> +
> +static void set_info_for_irq(unsigned int irq, struct irq_info *info)
> +{
> + if (irq < nr_legacy_irqs())
> + legacy_info_ptrs[irq] = info;
> + else
> + irq_set_chip_data(irq, info);
> }
>
> /* Constructors for packed IRQ information. */
> @@ -376,7 +389,7 @@ static void xen_irq_init(unsigned irq)
> info->type = IRQT_UNBOUND;
> info->refcnt = -1;
>
> - irq_set_chip_data(irq, info);
> + set_info_for_irq(irq, info);
>
> list_add_tail(&info->list, &xen_irq_list_head);
> }
> @@ -425,14 +438,14 @@ static int __must_check xen_allocate_irq_gsi(unsigned gsi)
>
> static void xen_free_irq(unsigned irq)
> {
> - struct irq_info *info = irq_get_chip_data(irq);
> + struct irq_info *info = info_for_irq(irq);
>
> if (WARN_ON(!info))
> return;
>
> list_del(&info->list);
>
> - irq_set_chip_data(irq, NULL);
> + set_info_for_irq(irq, NULL);
>
> WARN_ON(info->refcnt > 0);
>
> @@ -602,7 +615,7 @@ EXPORT_SYMBOL_GPL(xen_irq_from_gsi);
> static void __unbind_from_irq(unsigned int irq)
> {
> int evtchn = evtchn_from_irq(irq);
> - struct irq_info *info = irq_get_chip_data(irq);
> + struct irq_info *info = info_for_irq(irq);
>
> if (info->refcnt > 0) {
> info->refcnt--;
> @@ -1106,7 +1119,7 @@ int bind_ipi_to_irqhandler(enum ipi_vector ipi,
>
> void unbind_from_irqhandler(unsigned int irq, void *dev_id)
> {
> - struct irq_info *info = irq_get_chip_data(irq);
> + struct irq_info *info = info_for_irq(irq);
>
> if (WARN_ON(!info))
> return;
> @@ -1140,7 +1153,7 @@ int evtchn_make_refcounted(unsigned int evtchn)
> if (irq == -1)
> return -ENOENT;
>
> - info = irq_get_chip_data(irq);
> + info = info_for_irq(irq);
>
> if (!info)
> return -ENOENT;
> @@ -1168,7 +1181,7 @@ int evtchn_get(unsigned int evtchn)
> if (irq == -1)
> goto done;
>
> - info = irq_get_chip_data(irq);
> + info = info_for_irq(irq);
>
> if (!info)
> goto done;
>
next prev parent reply other threads:[~2020-10-14 9:31 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-05 6:19 [PATCH] xen/events: don't use chip_data for legacy IRQs Juergen Gross
2020-10-14 9:31 ` Jürgen Groß [this message]
2020-10-14 9:51 ` Greg KH
2020-10-14 10:44 ` Jürgen Groß
2020-10-16 8:06 ` Greg KH
-- strict thread matches above, loose matches on Subject: below --
2020-09-30 9:16 Juergen Gross
2020-09-30 12:06 ` Stefan Bader
2020-09-30 13:51 ` boris.ostrovsky
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