By using a pointer to struct dos_partition, we implicitly tell the
compiler that the pointer is 4-bytes aligned, even though we know
that's not the case. The fact that we only dereference the pointer
to access a byte-wide field (field dp_ptyp) is not a guarantee that
the compiler will in fact use a byte-wide load. On some platforms
it's more efficient to use long word or quad word loads and use
bit-shifting and bit-masking to get the intended byte. On those
platforms an misaligned load will be the result.
The fix is to use byte-wide pointer arithmetic based on sizeof() and
offsetof() to avoid invalid casts which avoids that the compiler
makes invalid assumptions.
Backtrace provided by: wilko@
MFC after: 1 week
axe_cmd() calls. Without this the device can get confused if multiple
threads attempt these operations concurrently. The problem was
easily reproducible by running "ifconfig axe0" in a loop because
eventually it would conflict with axe_tick_task().
A similar approach is probably required in all USB ethernet drivers.
- Add defines with block length for each HMAC algorithm.
- Add AES_BLOCK_LEN define which is an alias for RIJNDAEL128_BLOCK_LEN.
- Add NULL_BLOCK_LEN define.
Move the code for printing timer statistics into a test function instead of
an ifdef (accessible via the debug.acpi.hpet_test tunable). Also use defines
for register offsets instead of magic values.
Courtesy of: slow flight to HK
bread() the UFS superblock. Should eliminate crashes when trying
to do: mount -t ufs on an audio CD.
PR: kern/85893
Reported by: Russell Francis <rfrancis at ev dot net>
MFC after: 1 week
non-intuitive for the ~ to be built into the mask. All the users now
explicitly ~ the mask. In addition, add MTX_UNOWNED to the mask even
though it technically isn't a flag. This should unbreak mtx_owner().
Quickly spotted by: kris
it. We just moved it to be pci specific, so this was causing compile
problems (linking problems, so I didn't notice since I unwisely just
built the module).
vendor-specific device ids across vendors.
- Include the revision in the dc_devs[] array instead of special casing
the revid handling in dc_devtype().
- Use PCI bus accessors to read registers instead of pci_read_config()
where possible.
- Use an 8-bit write to update the latency timer.
- Use PCIR_xxx constants and remove unused DC_xxx related to standard
PCI config registers.
MFC after: 1 week
dropped. This prevents a bug introduced during the socket/pcb refcounting
work from occuring, in which occasionally the retransmit timer may fire
after a connection has been reset, resulting in the resulting R|A TCP
packet having a source port of 0, as the port reservation has been
released.
While here, fixing up some RUNLOCK->WUNLOCK bugs.
MFC after: 1 month
resulting in some build failures. Instead, to fix the problem of bpf not
being present, check the pointer before dereferencing it.
This is a temporary bandaid until we can decide on how we want to handle
the bpf code not being present. This will be fixed shortly.
forget to unbusy file system before its destruction.
This fixes the following warning on mount failure:
Mount point <X> had 1 dangling refs
Tested by: wkoszek
(1) bpf peer attaches to interface netif0
(2) Packet is received by netif0
(3) ifp->if_bpf pointer is checked and handed off to bpf
(4) bpf peer detaches from netif0 resulting in ifp->if_bpf being
initialized to NULL.
(5) ifp->if_bpf is dereferenced by bpf machinery
(6) Kaboom
This race condition likely explains the various different kernel panics
reported around sending SIGINT to tcpdump or dhclient processes. But really
this race can result in kernel panics anywhere you have frequent bpf attach
and detach operations with high packet per second load.
Summary of changes:
- Remove the bpf interface's "driverp" member
- When we attach bpf interfaces, we now set the ifp->if_bpf member to the
bpf interface structure. Once this is done, ifp->if_bpf should never be
NULL. [1]
- Introduce bpf_peers_present function, an inline operation which will do
a lockless read bpf peer list associated with the interface. It should
be noted that the bpf code will pickup the bpf_interface lock before adding
or removing bpf peers. This should serialize the access to the bpf descriptor
list, removing the race.
- Expose the bpf_if structure in bpf.h so that the bpf_peers_present function
can use it. This also removes the struct bpf_if; hack that was there.
- Adjust all consumers of the raw if_bpf structure to use bpf_peers_present
Now what happens is:
(1) Packet is received by netif0
(2) Check to see if bpf descriptor list is empty
(3) Pickup the bpf interface lock
(4) Hand packet off to process
From the attach/detach side:
(1) Pickup the bpf interface lock
(2) Add/remove from bpf descriptor list
Now that we are storing the bpf interface structure with the ifnet, there is
is no need to walk the bpf interface list to locate the correct bpf interface.
We now simply look up the interface, and initialize the pointer. This has a
nice side effect of changing a bpf interface attach operation from O(N) (where
N is the number of bpf interfaces), to O(1).
[1] From now on, we can no longer check ifp->if_bpf to tell us whether or
not we have any bpf peers that might be interested in receiving packets.
In collaboration with: sam@
MFC after: 1 month
