Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1308307 > unrolled thread

[PATCHv2 0/4] PCI VPD access fixes

Back to article view | Back to linux.kernel

Contents

  [PATCHv2 0/4] PCI VPD access fixes Hannes Reinecke <hare@suse.de> - 2016-01-13 12:30 +0100
    [PATCHv2 2/4] pci: allow access to VPD attributes with size '0' Hannes Reinecke <hare@suse.de> - 2016-01-13 12:30 +0100
    [PATCHv2 1/4] pci: Update VPD definitions Hannes Reinecke <hare@suse.de> - 2016-01-13 12:30 +0100
    RE: [PATCHv2 0/4] PCI VPD access fixes "Seymour, Shane M" <shane.seymour@hpe.com> - 2016-01-15 02:10 +0100

#1308307 — [PATCHv2 0/4] PCI VPD access fixes

Hi all,

the current PCI VPD page access assumes that the entire possible VPD
data is readable. However, the spec only guarantees a VPD data up to
the 'end' marker, with everything beyond that being undefined.
This causes a system lockup on certain devices.

With this patch we always set the VPD sysfs attribute size to '0', and
calculate the available VPD size on the first access.
If no valid data can be read an I/O error is returned.

I've also included the patch from Babu to blacklists devices which
are known to lockup when accessing the VPD data.

Babu Moger (1):
  pci: Blacklist vpd access for buggy devices

Hannes Reinecke (3):
  pci: Update VPD definitions
  pci: allow access to VPD attributes with size '0'
  pci: Determine actual VPD size on first access

 drivers/pci/access.c    | 79 ++++++++++++++++++++++++++++++++++++++++++++++++-
 drivers/pci/pci-sysfs.c | 22 ++++++++------
 drivers/pci/quirks.c    | 41 +++++++++++++++++++++++++
 include/linux/pci.h     | 27 +++++++++++++++--
 4 files changed, 157 insertions(+), 12 deletions(-)

-- 
1.8.5.6

[toc] | [next] | [standalone]

#1308308 — [PATCHv2 2/4] pci: allow access to VPD attributes with size '0'

It is not always possible to determine the actual size of the VPD
data, so allow access to them if the size is set to '0'.

Signed-off-by: Hannes Reinecke <hare@suse.de>
---
 drivers/pci/pci-sysfs.c | 20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index eead54c..de327c3 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -772,10 +772,12 @@ static ssize_t read_vpd_attr(struct file *filp, struct kobject *kobj,
 	struct pci_dev *dev =
 		to_pci_dev(container_of(kobj, struct device, kobj));
 
-	if (off > bin_attr->size)
-		count = 0;
-	else if (count > bin_attr->size - off)
-		count = bin_attr->size - off;
+	if (bin_attr->size > 0) {
+		if (off > bin_attr->size)
+			count = 0;
+		else if (count > bin_attr->size - off)
+			count = bin_attr->size - off;
+	}
 
 	return pci_read_vpd(dev, off, count, buf);
 }
@@ -787,10 +789,12 @@ static ssize_t write_vpd_attr(struct file *filp, struct kobject *kobj,
 	struct pci_dev *dev =
 		to_pci_dev(container_of(kobj, struct device, kobj));
 
-	if (off > bin_attr->size)
-		count = 0;
-	else if (count > bin_attr->size - off)
-		count = bin_attr->size - off;
+	if (bin_attr->size > 0) {
+		if (off > bin_attr->size)
+			count = 0;
+		else if (count > bin_attr->size - off)
+			count = bin_attr->size - off;
+	}
 
 	return pci_write_vpd(dev, off, count, buf);
 }
-- 
1.8.5.6

[toc] | [prev] | [next] | [standalone]

#1308311 — [PATCHv2 1/4] pci: Update VPD definitions

The 'end' tag is actually 0x0f, it's the representation as a
small resource data type tag that's 0x78 (ie shifted by 3).
This patch also adds helper functions to extract the resource
data type tags for both large and small resource data types.

Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Hannes Reinecke <hare@suse.com>
---
 include/linux/pci.h | 27 +++++++++++++++++++++++++--
 1 file changed, 25 insertions(+), 2 deletions(-)

diff --git a/include/linux/pci.h b/include/linux/pci.h
index d86378c..5d61c36 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1836,12 +1836,13 @@ bool pci_acs_path_enabled(struct pci_dev *start,
 #define PCI_VPD_LRDT_RW_DATA		PCI_VPD_LRDT_ID(PCI_VPD_LTIN_RW_DATA)
 
 /* Small Resource Data Type Tag Item Names */
-#define PCI_VPD_STIN_END		0x78	/* End */
+#define PCI_VPD_STIN_END		0x0f	/* End */
 
-#define PCI_VPD_SRDT_END		PCI_VPD_STIN_END
+#define PCI_VPD_SRDT_END		(PCI_VPD_STIN_END << 3)
 
 #define PCI_VPD_SRDT_TIN_MASK		0x78
 #define PCI_VPD_SRDT_LEN_MASK		0x07
+#define PCI_VPD_LRDT_TIN_MASK		0x7f
 
 #define PCI_VPD_LRDT_TAG_SIZE		3
 #define PCI_VPD_SRDT_TAG_SIZE		1
@@ -1865,6 +1866,17 @@ static inline u16 pci_vpd_lrdt_size(const u8 *lrdt)
 }
 
 /**
+ * pci_vpd_lrdt_tag - Extracts the Large Resource Data Type Tag Item
+ * @lrdt: Pointer to the beginning of the Large Resource Data Type tag
+ *
+ * Returns the extracted Large Resource Data Type Tag item.
+ */
+static inline u16 pci_vpd_lrdt_tag(const u8 *lrdt)
+{
+    return (u16)(lrdt[0] & PCI_VPD_LRDT_TIN_MASK);
+}
+
+/**
  * pci_vpd_srdt_size - Extracts the Small Resource Data Type length
  * @lrdt: Pointer to the beginning of the Small Resource Data Type tag
  *
@@ -1876,6 +1888,17 @@ static inline u8 pci_vpd_srdt_size(const u8 *srdt)
 }
 
 /**
+ * pci_vpd_srdt_tag - Extracts the Small Resource Data Type Tag Item
+ * @lrdt: Pointer to the beginning of the Small Resource Data Type tag
+ *
+ * Returns the extracted Small Resource Data Type Tag Item.
+ */
+static inline u8 pci_vpd_srdt_tag(const u8 *srdt)
+{
+	return ((*srdt) & PCI_VPD_SRDT_TIN_MASK) >> 3;
+}
+
+/**
  * pci_vpd_info_field_size - Extracts the information field length
  * @lrdt: Pointer to the beginning of an information field header
  *
-- 
1.8.5.6

[toc] | [prev] | [next] | [standalone]

#1309794

For the series. Tested with AE311 PCI-Express 4Gb Fibre Channel HBA.
Truncation of the vpd data returned works (154 bytes) and lspci -vvv
prints out the VPD tags the same way with and without the changes.
This card did not require any quirks it was capable of returning 32k
of data (although it repeated every 4k).
---
Tested-by: Shane Seymour <shane.seymour@hpe.com>

[toc] | [prev] | [standalone]

Back to top | Article view | linux.kernel

csiph-web