* [PATCH] genirq/affinity: add helper of irq_affinity_calc_sets
@ 2021-07-15 11:18 Ming Lei
2021-07-15 14:27 ` Bjorn Helgaas
2021-07-19 9:41 ` Christoph Hellwig
0 siblings, 2 replies; 4+ messages in thread
From: Ming Lei @ 2021-07-15 11:18 UTC (permalink / raw)
To: Thomas Gleixner
Cc: linux-kernel, Ming Lei, Bjorn Helgaas, linux-pci, Christoph Hellwig
When driver requests to allocate irq affinity managed vectors,
pci_alloc_irq_vectors_affinity() may fallback to single vector
allocation. In this situation, we don't need to call
irq_create_affinity_masks for calling into ->calc_sets() for
avoiding potential memory leak, so add the helper for this purpose.
Fixes: c66d4bd110a1 ("genirq/affinity: Add new callback for (re)calculating interrupt sets")
Reported-by: Bjorn Helgaas <helgaas@kernel.org>
Cc: linux-pci@vger.kernel.org
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
drivers/pci/msi.c | 3 ++-
include/linux/interrupt.h | 7 +++++++
kernel/irq/affinity.c | 29 ++++++++++++++++++-----------
3 files changed, 27 insertions(+), 12 deletions(-)
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 9232255c8515..3d6db20d1b2b 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -1224,7 +1224,8 @@ int pci_alloc_irq_vectors_affinity(struct pci_dev *dev, unsigned int min_vecs,
* for the single interrupt case.
*/
if (affd)
- irq_create_affinity_masks(1, affd);
+ WARN_ON_ONCE(irq_affinity_calc_sets(1, affd));
+
pci_intx(dev, 1);
return 1;
}
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index 2ed65b01c961..c7ff84d60465 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -340,6 +340,7 @@ irq_create_affinity_masks(unsigned int nvec, struct irq_affinity *affd);
unsigned int irq_calc_affinity_vectors(unsigned int minvec, unsigned int maxvec,
const struct irq_affinity *affd);
+int irq_affinity_calc_sets(unsigned int affvecs, struct irq_affinity *affd);
#else /* CONFIG_SMP */
@@ -391,6 +392,12 @@ irq_calc_affinity_vectors(unsigned int minvec, unsigned int maxvec,
return maxvec;
}
+static inline int irq_affinity_calc_sets(unsigned int affvecs,
+ struct irq_affinity *affd)
+{
+ return 0;
+}
+
#endif /* CONFIG_SMP */
/*
diff --git a/kernel/irq/affinity.c b/kernel/irq/affinity.c
index 4d89ad4fae3b..735f697d7d15 100644
--- a/kernel/irq/affinity.c
+++ b/kernel/irq/affinity.c
@@ -405,6 +405,23 @@ static void default_calc_sets(struct irq_affinity *affd, unsigned int affvecs)
affd->set_size[0] = affvecs;
}
+int irq_affinity_calc_sets(unsigned int affvecs, struct irq_affinity *affd)
+{
+ /*
+ * Simple invocations do not provide a calc_sets() callback. Install
+ * the generic one.
+ */
+ if (!affd->calc_sets)
+ affd->calc_sets = default_calc_sets;
+
+ /* Recalculate the sets */
+ affd->calc_sets(affd, affvecs);
+
+ if (affd->nr_sets > IRQ_AFFINITY_MAX_SETS)
+ return -ERANGE;
+ return 0;
+}
+
/**
* irq_create_affinity_masks - Create affinity masks for multiqueue spreading
* @nvecs: The total number of vectors
@@ -429,17 +446,7 @@ irq_create_affinity_masks(unsigned int nvecs, struct irq_affinity *affd)
else
affvecs = 0;
- /*
- * Simple invocations do not provide a calc_sets() callback. Install
- * the generic one.
- */
- if (!affd->calc_sets)
- affd->calc_sets = default_calc_sets;
-
- /* Recalculate the sets */
- affd->calc_sets(affd, affvecs);
-
- if (WARN_ON_ONCE(affd->nr_sets > IRQ_AFFINITY_MAX_SETS))
+ if (WARN_ON_ONCE(irq_affinity_calc_sets(affvecs, affd)))
return NULL;
/* Nothing to assign? */
--
2.31.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] genirq/affinity: add helper of irq_affinity_calc_sets
2021-07-15 11:18 [PATCH] genirq/affinity: add helper of irq_affinity_calc_sets Ming Lei
@ 2021-07-15 14:27 ` Bjorn Helgaas
2021-07-16 2:10 ` Ming Lei
2021-07-19 9:41 ` Christoph Hellwig
1 sibling, 1 reply; 4+ messages in thread
From: Bjorn Helgaas @ 2021-07-15 14:27 UTC (permalink / raw)
To: Ming Lei; +Cc: Thomas Gleixner, linux-kernel, linux-pci, Christoph Hellwig
On Thu, Jul 15, 2021 at 07:18:27PM +0800, Ming Lei wrote:
> When driver requests to allocate irq affinity managed vectors,
> pci_alloc_irq_vectors_affinity() may fallback to single vector
> allocation. In this situation, we don't need to call
> irq_create_affinity_masks for calling into ->calc_sets() for
> avoiding potential memory leak, so add the helper for this purpose.
>
> Fixes: c66d4bd110a1 ("genirq/affinity: Add new callback for (re)calculating interrupt sets")
> Reported-by: Bjorn Helgaas <helgaas@kernel.org>
> Cc: linux-pci@vger.kernel.org
> Cc: Christoph Hellwig <hch@lst.de>
> Signed-off-by: Ming Lei <ming.lei@redhat.com>
> ---
> drivers/pci/msi.c | 3 ++-
> include/linux/interrupt.h | 7 +++++++
> kernel/irq/affinity.c | 29 ++++++++++++++++++-----------
> 3 files changed, 27 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
> index 9232255c8515..3d6db20d1b2b 100644
> --- a/drivers/pci/msi.c
> +++ b/drivers/pci/msi.c
> @@ -1224,7 +1224,8 @@ int pci_alloc_irq_vectors_affinity(struct pci_dev *dev, unsigned int min_vecs,
> * for the single interrupt case.
> */
> if (affd)
> - irq_create_affinity_masks(1, affd);
> + WARN_ON_ONCE(irq_affinity_calc_sets(1, affd));
Hmmm. Not sure I like this yet:
- I prefer required code to be on its own, not hidden inside a
WARN() (personal preference, I know).
- WARN() doesn't seem like the right thing here. I think this
generates a backtrace but the driver that called this has no
indication. Isn't the problem that a .calc_sets() method set
"affd->nr_sets > IRQ_AFFINITY_MAX_SETS"?
It looks like those methods are supplied by drivers
(nvme_calc_irq_sets(), csio_calc_sets()) and it seems like they
should find out about this somehow.
> pci_intx(dev, 1);
> return 1;
> }
> diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
> index 2ed65b01c961..c7ff84d60465 100644
> --- a/include/linux/interrupt.h
> +++ b/include/linux/interrupt.h
> @@ -340,6 +340,7 @@ irq_create_affinity_masks(unsigned int nvec, struct irq_affinity *affd);
>
> unsigned int irq_calc_affinity_vectors(unsigned int minvec, unsigned int maxvec,
> const struct irq_affinity *affd);
> +int irq_affinity_calc_sets(unsigned int affvecs, struct irq_affinity *affd);
>
> #else /* CONFIG_SMP */
>
> @@ -391,6 +392,12 @@ irq_calc_affinity_vectors(unsigned int minvec, unsigned int maxvec,
> return maxvec;
> }
>
> +static inline int irq_affinity_calc_sets(unsigned int affvecs,
> + struct irq_affinity *affd)
> +{
> + return 0;
> +}
> +
> #endif /* CONFIG_SMP */
>
> /*
> diff --git a/kernel/irq/affinity.c b/kernel/irq/affinity.c
> index 4d89ad4fae3b..735f697d7d15 100644
> --- a/kernel/irq/affinity.c
> +++ b/kernel/irq/affinity.c
> @@ -405,6 +405,23 @@ static void default_calc_sets(struct irq_affinity *affd, unsigned int affvecs)
> affd->set_size[0] = affvecs;
> }
>
> +int irq_affinity_calc_sets(unsigned int affvecs, struct irq_affinity *affd)
> +{
> + /*
> + * Simple invocations do not provide a calc_sets() callback. Install
> + * the generic one.
> + */
> + if (!affd->calc_sets)
> + affd->calc_sets = default_calc_sets;
> +
> + /* Recalculate the sets */
> + affd->calc_sets(affd, affvecs);
> +
> + if (affd->nr_sets > IRQ_AFFINITY_MAX_SETS)
> + return -ERANGE;
> + return 0;
> +}
> +
> /**
> * irq_create_affinity_masks - Create affinity masks for multiqueue spreading
> * @nvecs: The total number of vectors
> @@ -429,17 +446,7 @@ irq_create_affinity_masks(unsigned int nvecs, struct irq_affinity *affd)
> else
> affvecs = 0;
>
> - /*
> - * Simple invocations do not provide a calc_sets() callback. Install
> - * the generic one.
> - */
> - if (!affd->calc_sets)
> - affd->calc_sets = default_calc_sets;
> -
> - /* Recalculate the sets */
> - affd->calc_sets(affd, affvecs);
> -
> - if (WARN_ON_ONCE(affd->nr_sets > IRQ_AFFINITY_MAX_SETS))
> + if (WARN_ON_ONCE(irq_affinity_calc_sets(affvecs, affd)))
> return NULL;
>
> /* Nothing to assign? */
> --
> 2.31.1
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] genirq/affinity: add helper of irq_affinity_calc_sets
2021-07-15 14:27 ` Bjorn Helgaas
@ 2021-07-16 2:10 ` Ming Lei
0 siblings, 0 replies; 4+ messages in thread
From: Ming Lei @ 2021-07-16 2:10 UTC (permalink / raw)
To: Bjorn Helgaas; +Cc: Thomas Gleixner, linux-kernel, linux-pci, Christoph Hellwig
On Thu, Jul 15, 2021 at 09:27:14AM -0500, Bjorn Helgaas wrote:
> On Thu, Jul 15, 2021 at 07:18:27PM +0800, Ming Lei wrote:
> > When driver requests to allocate irq affinity managed vectors,
> > pci_alloc_irq_vectors_affinity() may fallback to single vector
> > allocation. In this situation, we don't need to call
> > irq_create_affinity_masks for calling into ->calc_sets() for
> > avoiding potential memory leak, so add the helper for this purpose.
> >
> > Fixes: c66d4bd110a1 ("genirq/affinity: Add new callback for (re)calculating interrupt sets")
> > Reported-by: Bjorn Helgaas <helgaas@kernel.org>
> > Cc: linux-pci@vger.kernel.org
> > Cc: Christoph Hellwig <hch@lst.de>
> > Signed-off-by: Ming Lei <ming.lei@redhat.com>
> > ---
> > drivers/pci/msi.c | 3 ++-
> > include/linux/interrupt.h | 7 +++++++
> > kernel/irq/affinity.c | 29 ++++++++++++++++++-----------
> > 3 files changed, 27 insertions(+), 12 deletions(-)
> >
> > diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
> > index 9232255c8515..3d6db20d1b2b 100644
> > --- a/drivers/pci/msi.c
> > +++ b/drivers/pci/msi.c
> > @@ -1224,7 +1224,8 @@ int pci_alloc_irq_vectors_affinity(struct pci_dev *dev, unsigned int min_vecs,
> > * for the single interrupt case.
> > */
> > if (affd)
> > - irq_create_affinity_masks(1, affd);
> > + WARN_ON_ONCE(irq_affinity_calc_sets(1, affd));
>
> Hmmm. Not sure I like this yet:
>
> - I prefer required code to be on its own, not hidden inside a
> WARN() (personal preference, I know).
>
> - WARN() doesn't seem like the right thing here. I think this
> generates a backtrace but the driver that called this has no
> indication. Isn't the problem that a .calc_sets() method set
> "affd->nr_sets > IRQ_AFFINITY_MAX_SETS"?
Yes. When the warning is triggered, memory corruption may have been caused,
not sure if the indication is needed.
>
> It looks like those methods are supplied by drivers
> (nvme_calc_irq_sets(), csio_calc_sets()) and it seems like they
> should find out about this somehow.
Yeah. The WARN() here is just to report the bug earlier.
Thanks,
Ming
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] genirq/affinity: add helper of irq_affinity_calc_sets
2021-07-15 11:18 [PATCH] genirq/affinity: add helper of irq_affinity_calc_sets Ming Lei
2021-07-15 14:27 ` Bjorn Helgaas
@ 2021-07-19 9:41 ` Christoph Hellwig
1 sibling, 0 replies; 4+ messages in thread
From: Christoph Hellwig @ 2021-07-19 9:41 UTC (permalink / raw)
To: Ming Lei
Cc: Thomas Gleixner, linux-kernel, Bjorn Helgaas, linux-pci,
Christoph Hellwig
On Thu, Jul 15, 2021 at 07:18:27PM +0800, Ming Lei wrote:
> + WARN_ON_ONCE(irq_affinity_calc_sets(1, affd));
Hiding actual functionality inside a WARN_ON is nasty.
> +int irq_affinity_calc_sets(unsigned int affvecs, struct irq_affinity *affd)
> +{
> + /*
> + * Simple invocations do not provide a calc_sets() callback. Install
> + * the generic one.
> + */
> + if (!affd->calc_sets)
> + affd->calc_sets = default_calc_sets;
> +
> + /* Recalculate the sets */
> + affd->calc_sets(affd, affvecs);
I'm not sure a function like this should have side effects. Either
we move the assign to an init function with a single caller, or do an
if / else here.
^ permalink raw reply [flat|nested] 4+ messages in thread
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2021-07-15 11:18 [PATCH] genirq/affinity: add helper of irq_affinity_calc_sets Ming Lei
2021-07-15 14:27 ` Bjorn Helgaas
2021-07-16 2:10 ` Ming Lei
2021-07-19 9:41 ` Christoph Hellwig
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