Xiaoliang (David) Wei wrote:
> Hi gurus,
>
> I am reading the code of tcp_highspeed.c in the kernel and have a
> question on the hstcp_cong_avoid function, specifically the following
> AI part (line 136~143 in net/ipv4/tcp_highspeed.c ):
>
> /* Do additive increase */
> if (tp->snd_cwnd < tp->snd_cwnd_clamp) {
> tp->snd_cwnd_cnt += ca->ai;
> if (tp->snd_cwnd_cnt >= tp->snd_cwnd) {
> tp->snd_cwnd++;
> tp->snd_cwnd_cnt -= tp->snd_cwnd;
> }
> }
>
> In this part, when (tp->snd_cwnd_cnt == tp->snd_cwnd),
> snd_cwnd_cnt will be -1... snd_cwnd_cnt is defined as u16, will this
> small chance of getting -1 becomes a problem?
> Shall we change it by reversing the order of the cwnd++ and cwnd_cnt -=
> cwnd?
Absolutely correct. Thanks.
Signed-off-by: John Heffner <jheffner@psc.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
There are out of date and don't tell the user anything useful.
The similar messages which IPV4 and the core networking used
to output were killed a long time ago.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Calling sock_orphan inside bh_lock_sock in dccp_close can lead to dead
locks. For example, the inet_diag code holds sk_callback_lock without
disabling BH. If an inbound packet arrives during that admittedly tiny
window, it will cause a dead lock on bh_lock_sock. Another possible
path would be through sock_wfree if the network device driver frees the
tx skb in process context with BH enabled.
We can fix this by moving sock_orphan out of bh_lock_sock.
The tricky bit is to work out when we need to destroy the socket
ourselves and when it has already been destroyed by someone else.
By moving sock_orphan before the release_sock we can solve this
problem. This is because as long as we own the socket lock its
state cannot change.
So we simply record the socket state before the release_sock
and then check the state again after we regain the socket lock.
If the socket state has transitioned to DCCP_CLOSED in the time being,
we know that the socket has been destroyed. Otherwise the socket is
still ours to keep.
This problem was discoverd by Ingo Molnar using his lock validator.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
It makes sense to add this simple statistic to keep track of received
multicast packets.
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Discard an unexpected chunk in CLOSED state rather can calling BUG().
Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use pskb_pull() to handle incoming COOKIE_ECHO and HEARTBEAT chunks that
are received as skb's with fragment list.
Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
There is a rare situation that causes lksctp to go into infinite recursion
and crash the system. The trigger is a packet that contains at least the
first two DATA fragments of a message bundled together. The recursion is
triggered when the user data buffer is smaller that the full data message.
The problem is that we clone the skb for every fragment in the message.
When reassembling the full message, we try to link skbs from the "first
fragment" clone using the frag_list. However, since the frag_list is shared
between two clones in this rare situation, we end up setting the frag_list
pointer of the second fragment to point to itself. This causes
sctp_skb_pull() to potentially recurse indefinitely.
Proposed solution is to make a copy of the skb when attempting to link
things using frag_list.
Signed-off-by: Vladislav Yasevich <vladsilav.yasevich@hp.com>
Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch fixes a deadlock situation in the receive path by allowing
temporary spillover of the receive buffer.
- If the chunk we receive has a tsn that immediately follows the ctsn,
accept it even if we run out of receive buffer space and renege data with
higher TSNs.
- Once we accept one chunk in a packet, accept all the remaining chunks
even if we run out of receive buffer space.
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Mark Butler <butlerm@middle.net>
Acked-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
It seems like there is a potential race in the function jffs2_do_setattr()
in the case when attributes of a symlink are updated. The symlink metadata
is read without having f->sem locked.
The following patch should fix the race.
Signed-off-by: Dmitry Bazhenov <atrey@emcraft.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Patch from Nicolas Pitre
... but only for user space.
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Nicolas Pitre
Intel PXA27x developers manual section 5.4.1.1 lists a priority
distribution for the DMA channels differently than what the code
currently assumes. This patch fixes that.
Noticed by Simon Vogl <vogl@soft.uni-linz.ac.at>
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from George G. Davis
The ARM VFP FPSCR register is corrupted when a condition flags modifying
VFP instruction is followed by a non-condition flags modifying VFP
instruction and both instructions raise exceptions. The fix is to
read the current FPSCR in between emulation of these two instructions
and use the current FPSCR value when handling the second exception.
Signed-off-by: George G. Davis <gdavis@mvista.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Fix the conditions under which we poke at the APHY registers in
bcm43xx_phy_initg() to avoid a machine check on chips where they don't
exist.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The problem here is that the bcm34xx driver and the ieee80211
stack do not agree on what channels are possible for 802.11a.
The ieee80211 stack only wants channels between 34 and 165, while
the bcm43xx driver accepts anything from 0 to 200. I made the
bcm43xx driver comply with the ieee80211 stack expectations, by
using the proper constants.
Signed-off-by: Jean Delvare <jdelvare@suse.de>
[mb]: Reduce stack usage by kzalloc-ing ieee80211_geo
Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Check for valid MAC address in SPROM fields instead of relying on
PHY type while setting the MAC address in the networking subsystem,
as some devices have multiple PHYs.
Signed-off-by: Stefano Brivio <stefano.brivio@polimi.it>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The channel count for 802.11a is still not right. We better
compute it from the min and max channel numbers, rather than
hardcoding it.
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This fixes a crash when
iwconfig ethX mode foo
is done before
ifconfig ethX up
or after
ifconfig ethX down
Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
zd1211 with softmac and wpa_supplicant revealed an issue with softmac
and the use of workqueues. Some of the work functions actually
reschedule themselves, so this meant that there could still be
pending work after flush_scheduled_work() had been called during
ieee80211softmac_stop().
This patch introduces a "running" flag which is used to ensure that
rescheduling does not happen in this situation.
I also used this flag to ensure that softmac's hooks into ieee80211 are
non-operational once the stop operation has been started. This simply
makes softmac a little more robust, because I could crash it easily
by receiving frames in the short timeframe after shutting down softmac
and before turning off the ZD1211 radio. (ZD1211 is now fixed as well!)
Signed-off-by: Daniel Drake <dsd@gentoo.org>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
When wpa_supplicant exits, it uses SIOCSIWMLME to request
deauthentication. softmac then tries to reassociate without any user
intervention, which isn't the desired behaviour of this signal.
This change makes softmac only attempt reassociation if the remote
network itself deauthenticated us.
Signed-off-by: Daniel Drake <dsd@gentoo.org>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
asm-ia64/bitops.h includes itself. The #ifndef _ASM_IA64_BITOPS_H
prevents this from being an issue, but it should still be removed.
Signed-off-by: Jon Mason <jdmason@us.ibm.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Bob Picco noted that 6edfba1b33
dropped the -ffreestanding compiler flag from the top level
Makefile, which allows the compiler to substitute memcpy() in
places where strcpy() is used with a known size source string.
But the ia64 memcpy() returns 0 for success, and "bytes copied"
for failure.
Fix to return the address of the destination string (like
stdlibc version, and other architectures). There are no
places where ia64 specific code makes use of the non-standard
return value.
Signed-off-by: Ken Chen <kenneth.w.chen@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
The block layer keeps a reference (driverfs_dev) to the struct
device associated with the block device, and uses it internally
for generating uevents in block_uevent.
Block device uevents include umounting the partition, which can
occur after the backing device has been removed.
Unfortunately, this reference is not counted. This means that
if the struct device is removed from the device tree, the block
layers reference will become stale.
Guard against this by holding a reference to the struct device
in add_disk(), and only drop the reference when we're releasing
the gendisk kobject - in other words when we can be sure that no
further uevents will be generated for this block device.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Jens Axboe <axboe@suse.de>
Patch from Uwe Zeisberger
added the following constants:
- MACHINFO_TYPE
- MACHINFO_NAME
- MACHINFO_PHYSIO
- MACHINFO_PGOFFIO
- PROCINFO_INITFUNC
- PROCINFO_MMUFLAGS
and removed their definition from head.S and head-nommu.S
Signed-off-by: Uwe Zeisberger <Uwe_Zeisberger@digi.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Nicolas Pitre
... for the definition of NULL.
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc:
[PATCH] powerpc: Use the ibm,pa-features property if available
powerpc: Fix incorrect might_sleep in __get_user/__put_user on kernel addresses
[PATCH] ppc32 CPM_UART: fixes and improvements
[PATCH] ppc32 CPM_UART: Fixed break send on SCC
[PATCH] powerpc/kprobes: fix singlestep out-of-line
[PATCH] powerpc/pseries: avoid crash in PCI code if mem system not up
* master.kernel.org:/home/rmk/linux-2.6-arm:
[ARM] 3490/1: i.MX: move uart resources to board files
[ARM] 3488/1: make icedcc_putc do the right thing
[ARM] 3487/1: IXP4xx: Support non-PCI systems
[ARM] 3486/1: Mark memory as clobbered by the ARM _syscallX() macros
Rather than having every driver duplicate the set_ios debugging,
provide a single version in mmc.c which can be expanded as we
add additional functionality.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Sascha Hauer
This patch moves the i.MX uart resources and the gpio pin setup to the
board files. This allows the boards to decide how many internal uarts
are connected to the outside world and whether they use rts/cts or
not.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
mmc_request_done should be called at the end of handling a request, not
between the data and initial command parts of the request.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
nr_segs may not be > UIO_MAXIOV, however it may be equal to. This makes
the behaviour identical to the real sys_vmsplice(). The other foov
syscalls also agree that this is the way to go.
Signed-off-by: Jens Axboe <axboe@suse.de>
This patch fixes hello messages sent when a node is a level 1
router. Slightly contrary to the spec (maybe) VMS ignores hello
messages that do not name level2 routers that it also knows about.
So, here we simply name all the routers that the node knows about
rather just other level1 routers. (I hope the patch is clearer than
the description. sorry).
Signed-off-by: Patrick Caulfield <patrick@tykepenguin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Calling sock_orphan inside bh_lock_sock in tcp_close can lead to dead
locks. For example, the inet_diag code holds sk_callback_lock without
disabling BH. If an inbound packet arrives during that admittedly tiny
window, it will cause a dead lock on bh_lock_sock. Another possible
path would be through sock_wfree if the network device driver frees the
tx skb in process context with BH enabled.
We can fix this by moving sock_orphan out of bh_lock_sock.
The tricky bit is to work out when we need to destroy the socket
ourselves and when it has already been destroyed by someone else.
By moving sock_orphan before the release_sock we can solve this
problem. This is because as long as we own the socket lock its
state cannot change.
So we simply record the socket state before the release_sock
and then check the state again after we regain the socket lock.
If the socket state has transitioned to TCP_CLOSE in the time being,
we know that the socket has been destroyed. Otherwise the socket is
still ours to keep.
Note that I've also moved the increment on the orphan count forward.
This may look like a problem as we're increasing it even if the socket
is just about to be destroyed where it'll be decreased again. However,
this simply enlarges a window that already exists. This also changes
the orphan count test by one.
Considering what the orphan count is meant to do this is no big deal.
This problem was discoverd by Ingo Molnar using his lock validator.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Convert all ROSE sysctl time values from jiffies to ms as units.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Convert all NET/ROM sysctl time values from jiffies to ms as units.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Convert all AX.25 sysctl time values from jiffies to ms as units.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The locking rule for rose_remove_neigh() are that the caller needs to
hold rose_neigh_list_lock, so we better don't take it yet again in
rose_neigh_list_lock.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Move AX.25 symbol exports to next to their definitions where they're
supposed to be these days.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jing Min Zhao <zhaojingmin@users.sourceforge.net>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/ipv4/netfilter/ip_nat_standalone.c: In function 'ip_nat_out':
net/ipv4/netfilter/ip_nat_standalone.c:223: warning: unused variable 'ctinfo'
net/ipv4/netfilter/ip_nat_standalone.c:222: warning: unused variable 'ct'
Surprisingly no complaints so far ..
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
