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| author | Bjorn Helgaas <bhelgaas@google.com> | 2017-01-27 15:00:45 -0600 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2017-01-27 15:00:45 -0600 |
| commit | 030305d69fc6963c16003f50d7e8d74b02d0a143 (patch) | |
| tree | 363a4e34d199178769b7e7eeb26ea2620a55847b /net/decnet/README | |
| parent | 4d191b1b63c209e37bf27938ef365244d3c41084 (diff) | |
PCI/ASPM: Handle PCI-to-PCIe bridges as roots of PCIe hierarchies
In a struct pcie_link_state, link->root points to the pcie_link_state of
the root of the PCIe hierarchy. For the topmost link, this points to
itself (link->root = link). For others, we copy the pointer from the
parent (link->root = link->parent->root).
Previously we recognized that Root Ports originated PCIe hierarchies, but
we treated PCI/PCI-X to PCIe Bridges as being in the middle of the
hierarchy, and when we tried to copy the pointer from link->parent->root,
there was no parent, and we dereferenced a NULL pointer:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000090
IP: [<ffffffff9e424350>] pcie_aspm_init_link_state+0x170/0x820
Recognize that PCI/PCI-X to PCIe Bridges originate PCIe hierarchies just
like Root Ports do, so link->root for these devices should also point to
itself.
Fixes: 51ebfc92b72b ("PCI: Enumerate switches below PCI-to-PCIe bridges")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=193411
Link: https://bugzilla.opensuse.org/show_bug.cgi?id=1022181
Tested-by: lists@ssl-mail.com
Tested-by: Jayachandran C. <jnair@caviumnetworks.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: stable@vger.kernel.org # v4.2+
Diffstat (limited to 'net/decnet/README')