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| author | Andrey Grodzovsky <andrey2805@gmail.com> | 2016-06-21 14:26:36 -0400 |
|---|---|---|
| committer | David Vrabel <david.vrabel@citrix.com> | 2016-06-23 11:36:15 +0100 |
| commit | 02ef871ecac290919ea0c783d05da7eedeffc10e (patch) | |
| tree | a66c1f3065cbcd2756b0bbb1e3a4c2cc504af004 /drivers/xen | |
| parent | 1cf38741308c64d08553602b3374fb39224eeb5a (diff) | |
| download | linux-02ef871ecac290919ea0c783d05da7eedeffc10e.tar.bz2 | |
xen/pciback: Fix conf_space read/write overlap check.
Current overlap check is evaluating to false a case where a filter
field is fully contained (proper subset) of a r/w request. This
change applies classical overlap check instead to include all the
scenarios.
More specifically, for (Hilscher GmbH CIFX 50E-DP(M/S)) device driver
the logic is such that the entire confspace is read and written in 4
byte chunks. In this case as an example, CACHE_LINE_SIZE,
LATENCY_TIMER and PCI_BIST are arriving together in one call to
xen_pcibk_config_write() with offset == 0xc and size == 4. With the
exsisting overlap check the LATENCY_TIMER field (offset == 0xd, length
== 1) is fully contained in the write request and hence is excluded
from write, which is incorrect.
Signed-off-by: Andrey Grodzovsky <andrey2805@gmail.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Jan Beulich <JBeulich@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Diffstat (limited to 'drivers/xen')
| -rw-r--r-- | drivers/xen/xen-pciback/conf_space.c | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/drivers/xen/xen-pciback/conf_space.c b/drivers/xen/xen-pciback/conf_space.c index 8e67336f8ddd..6a25533da237 100644 --- a/drivers/xen/xen-pciback/conf_space.c +++ b/drivers/xen/xen-pciback/conf_space.c @@ -183,8 +183,7 @@ int xen_pcibk_config_read(struct pci_dev *dev, int offset, int size, field_start = OFFSET(cfg_entry); field_end = OFFSET(cfg_entry) + field->size; - if ((req_start >= field_start && req_start < field_end) - || (req_end > field_start && req_end <= field_end)) { + if (req_end > field_start && field_end > req_start) { err = conf_space_read(dev, cfg_entry, field_start, &tmp_val); if (err) @@ -230,8 +229,7 @@ int xen_pcibk_config_write(struct pci_dev *dev, int offset, int size, u32 value) field_start = OFFSET(cfg_entry); field_end = OFFSET(cfg_entry) + field->size; - if ((req_start >= field_start && req_start < field_end) - || (req_end > field_start && req_end <= field_end)) { + if (req_end > field_start && field_end > req_start) { tmp_val = 0; err = xen_pcibk_config_read(dev, field_start, |