| Message ID | 20210715111827.569756-1-ming.lei@redhat.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
| Series | genirq/affinity: add helper of irq_affinity_calc_sets | expand |
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 >
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
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.
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? */
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(-)