diff mbox series

[33/39] PCI/MSI: Sanitize MSI-X checks

Message ID 20221111122015.516946468@linutronix.de (mailing list archive)
State Handled Elsewhere
Headers show
Series genirq, PCI/MSI: Support for per device MSI and PCI/IMS - Part 1 cleanups | expand

Commit Message

Thomas Gleixner Nov. 11, 2022, 1:55 p.m. UTC 
There is no point in doing the same sanity checks over and over in a loop
during MSI-X enablement. Put them in front of the loop and return early
when they fail.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 drivers/pci/msi/msi.c |   67 +++++++++++++++++++++++++-------------------------
 1 file changed, 34 insertions(+), 33 deletions(-)

Comments

Bjorn Helgaas Nov. 16, 2022, 4:29 p.m. UTC | #1 
On Fri, Nov 11, 2022 at 02:55:07PM +0100, Thomas Gleixner wrote:
> There is no point in doing the same sanity checks over and over in a loop
> during MSI-X enablement. Put them in front of the loop and return early
> when they fail.
> 
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Acked-by: Bjorn Helgaas <bhelgaas@google.com>

> ---
>  drivers/pci/msi/msi.c |   67 +++++++++++++++++++++++++-------------------------
>  1 file changed, 34 insertions(+), 33 deletions(-)
> 
> --- a/drivers/pci/msi/msi.c
> +++ b/drivers/pci/msi/msi.c
> @@ -721,47 +721,31 @@ static int msix_capability_init(struct p
>  	return ret;
>  }
>  
> -static int __pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries,
> -			     int nvec, struct irq_affinity *affd, int flags)
> +static bool pci_msix_validate_entries(struct msix_entry *entries, int nvec, int hwsize)
>  {
> -	int nr_entries;
>  	int i, j;
>  
> -	if (!pci_msi_supported(dev, nvec) || dev->current_state != PCI_D0)
> -		return -EINVAL;
> +	if (!entries)
> +		return true;
>  
> -	nr_entries = pci_msix_vec_count(dev);
> -	if (nr_entries < 0)
> -		return nr_entries;
> -	if (nvec > nr_entries && !(flags & PCI_IRQ_VIRTUAL))
> -		return nr_entries;
> -
> -	if (entries) {
> -		/* Check for any invalid entries */
> -		for (i = 0; i < nvec; i++) {
> -			if (entries[i].entry >= nr_entries)
> -				return -EINVAL;		/* invalid entry */
> -			for (j = i + 1; j < nvec; j++) {
> -				if (entries[i].entry == entries[j].entry)
> -					return -EINVAL;	/* duplicate entry */
> -			}
> +	for (i = 0; i < nvec; i++) {
> +		/* Entry within hardware limit? */
> +		if (entries[i].entry >= hwsize)
> +			return false;
> +
> +		/* Check for duplicate entries */
> +		for (j = i + 1; j < nvec; j++) {
> +			if (entries[i].entry == entries[j].entry)
> +				return false;
>  		}
>  	}
> -
> -	/* Check whether driver already requested for MSI IRQ */
> -	if (dev->msi_enabled) {
> -		pci_info(dev, "can't enable MSI-X (MSI IRQ already assigned)\n");
> -		return -EINVAL;
> -	}
> -	return msix_capability_init(dev, entries, nvec, affd);
> +	return true;
>  }
>  
> -int __pci_enable_msix_range(struct pci_dev *dev,
> -			    struct msix_entry *entries, int minvec,
> -			    int maxvec, struct irq_affinity *affd,
> -			    int flags)
> +int __pci_enable_msix_range(struct pci_dev *dev, struct msix_entry *entries, int minvec,
> +			    int maxvec, struct irq_affinity *affd, int flags)
>  {
> -	int rc, nvec = maxvec;
> +	int hwsize, rc, nvec = maxvec;
>  
>  	if (maxvec < minvec)
>  		return -ERANGE;
> @@ -774,6 +758,23 @@ int __pci_enable_msix_range(struct pci_d
>  	if (WARN_ON_ONCE(dev->msix_enabled))
>  		return -EINVAL;
>  
> +	if (!pci_msi_supported(dev, nvec) || dev->current_state != PCI_D0)
> +		return -EINVAL;
> +
> +	hwsize = pci_msix_vec_count(dev);
> +	if (hwsize < 0)
> +		return hwsize;
> +
> +	if (!pci_msix_validate_entries(entries, nvec, hwsize))
> +		return -EINVAL;
> +
> +	/* PCI_IRQ_VIRTUAL is a horrible hack! */
> +	if (nvec > hwsize && !(flags & PCI_IRQ_VIRTUAL))
> +		nvec = hwsize;
> +
> +	if (nvec < minvec)
> +		return -ENOSPC;
> +
>  	rc = pci_setup_msi_context(dev);
>  	if (rc)
>  		return rc;
> @@ -785,7 +786,7 @@ int __pci_enable_msix_range(struct pci_d
>  				return -ENOSPC;
>  		}
>  
> -		rc = __pci_enable_msix(dev, entries, nvec, affd, flags);
> +		rc = msix_capability_init(dev, entries, nvec, affd);
>  		if (rc == 0)
>  			return nvec;
>  
>
Jason Gunthorpe Nov. 16, 2022, 5:57 p.m. UTC | #2 
On Fri, Nov 11, 2022 at 02:55:07PM +0100, Thomas Gleixner wrote:
> There is no point in doing the same sanity checks over and over in a loop
> during MSI-X enablement. Put them in front of the loop and return early
> when they fail.
> 
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> ---
>  drivers/pci/msi/msi.c |   67 +++++++++++++++++++++++++-------------------------
>  1 file changed, 34 insertions(+), 33 deletions(-)

> +	/* PCI_IRQ_VIRTUAL is a horrible hack! */

New comment too :)

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>

Jason
Tian, Kevin Nov. 18, 2022, 7:38 a.m. UTC | #3 
> From: Thomas Gleixner <tglx@linutronix.de>
> Sent: Friday, November 11, 2022 9:55 PM
> 
> @@ -785,7 +786,7 @@ int __pci_enable_msix_range(struct pci_d
>  				return -ENOSPC;
>  		}
> 
> -		rc = __pci_enable_msix(dev, entries, nvec, affd, flags);
> +		rc = msix_capability_init(dev, entries, nvec, affd);
>  		if (rc == 0)
>  			return nvec;
> 

The check in following lines doesn't make sense now:

		if (rc < minvec)
			return -ENOSPC;
diff mbox series

Patch

--- a/drivers/pci/msi/msi.c
+++ b/drivers/pci/msi/msi.c
@@ -721,47 +721,31 @@  static int msix_capability_init(struct p
 	return ret;
 }
 
-static int __pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries,
-			     int nvec, struct irq_affinity *affd, int flags)
+static bool pci_msix_validate_entries(struct msix_entry *entries, int nvec, int hwsize)
 {
-	int nr_entries;
 	int i, j;
 
-	if (!pci_msi_supported(dev, nvec) || dev->current_state != PCI_D0)
-		return -EINVAL;
+	if (!entries)
+		return true;
 
-	nr_entries = pci_msix_vec_count(dev);
-	if (nr_entries < 0)
-		return nr_entries;
-	if (nvec > nr_entries && !(flags & PCI_IRQ_VIRTUAL))
-		return nr_entries;
-
-	if (entries) {
-		/* Check for any invalid entries */
-		for (i = 0; i < nvec; i++) {
-			if (entries[i].entry >= nr_entries)
-				return -EINVAL;		/* invalid entry */
-			for (j = i + 1; j < nvec; j++) {
-				if (entries[i].entry == entries[j].entry)
-					return -EINVAL;	/* duplicate entry */
-			}
+	for (i = 0; i < nvec; i++) {
+		/* Entry within hardware limit? */
+		if (entries[i].entry >= hwsize)
+			return false;
+
+		/* Check for duplicate entries */
+		for (j = i + 1; j < nvec; j++) {
+			if (entries[i].entry == entries[j].entry)
+				return false;
 		}
 	}
-
-	/* Check whether driver already requested for MSI IRQ */
-	if (dev->msi_enabled) {
-		pci_info(dev, "can't enable MSI-X (MSI IRQ already assigned)\n");
-		return -EINVAL;
-	}
-	return msix_capability_init(dev, entries, nvec, affd);
+	return true;
 }
 
-int __pci_enable_msix_range(struct pci_dev *dev,
-			    struct msix_entry *entries, int minvec,
-			    int maxvec, struct irq_affinity *affd,
-			    int flags)
+int __pci_enable_msix_range(struct pci_dev *dev, struct msix_entry *entries, int minvec,
+			    int maxvec, struct irq_affinity *affd, int flags)
 {
-	int rc, nvec = maxvec;
+	int hwsize, rc, nvec = maxvec;
 
 	if (maxvec < minvec)
 		return -ERANGE;
@@ -774,6 +758,23 @@  int __pci_enable_msix_range(struct pci_d
 	if (WARN_ON_ONCE(dev->msix_enabled))
 		return -EINVAL;
 
+	if (!pci_msi_supported(dev, nvec) || dev->current_state != PCI_D0)
+		return -EINVAL;
+
+	hwsize = pci_msix_vec_count(dev);
+	if (hwsize < 0)
+		return hwsize;
+
+	if (!pci_msix_validate_entries(entries, nvec, hwsize))
+		return -EINVAL;
+
+	/* PCI_IRQ_VIRTUAL is a horrible hack! */
+	if (nvec > hwsize && !(flags & PCI_IRQ_VIRTUAL))
+		nvec = hwsize;
+
+	if (nvec < minvec)
+		return -ENOSPC;
+
 	rc = pci_setup_msi_context(dev);
 	if (rc)
 		return rc;
@@ -785,7 +786,7 @@  int __pci_enable_msix_range(struct pci_d
 				return -ENOSPC;
 		}
 
-		rc = __pci_enable_msix(dev, entries, nvec, affd, flags);
+		rc = msix_capability_init(dev, entries, nvec, affd);
 		if (rc == 0)
 			return nvec;