# # CCITT X.25 Packet Layer # config X25 tristate "CCITT X.25 Packet Layer" ---help--- X.25 is a set of standardized network protocols, similar in scope to frame relay; the one physical line from your box to the X.25 network entry point can carry several logical point-to-point connections (called "virtual circuits") to other computers connected to the X.25 network. Governments, banks, and other organizations tend to use it to connect to each other or to form Wide Area Networks (WANs). Many countries have public X.25 networks. X.25 consists of two protocols: the higher level Packet Layer Protocol (PLP) (say Y here if you want that) and the lower level data link layer protocol LAPB (say Y to "LAPB Data Link Driver" below if you want that). You can read more about X.25 at and . Information about X.25 for Linux is contained in the files and . One connects to an X.25 network either with a dedicated network card using the X.21 protocol (not yet supported by Linux) or one can do X.25 over a standard telephone line using an ordinary modem (say Y to "X.25 async driver" below) or over Ethernet using an ordinary Ethernet card and the LAPB over Ethernet (say Y to "LAPB Data Link Driver" and "LAPB over Ethernet driver" below). To compile this driver as a module, choose M here: the module will be called x25. If unsure, say N. net-next.git/'>summaryrefslogtreecommitdiff
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authorBjorn Helgaas <bhelgaas@google.com>2017-01-27 15:00:45 -0600
committerBjorn Helgaas <bhelgaas@google.com>2017-01-27 15:00:45 -0600
commit030305d69fc6963c16003f50d7e8d74b02d0a143 (patch)
tree363a4e34d199178769b7e7eeb26ea2620a55847b /net/sunrpc/rpc_pipe.c
parent4d191b1b63c209e37bf27938ef365244d3c41084 (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/sunrpc/rpc_pipe.c')