The attached patch uses RCU to manage the session keyring pointer in struct
signal_struct. This means that searching need not disable interrupts and get
a the sighand spinlock to access this pointer. Furthermore, by judicious use
of rcu_read_(un)lock(), this patch also avoids the need to take and put
refcounts on the session keyring itself, thus saving on even more atomic ops.
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The attached patch makes it possible to pass a session keyring through to the
process spawned by call_usermodehelper(). This allows patch 3/3 to pass an
authorisation key through to /sbin/request-key, thus permitting better access
controls when doing just-in-time key creation.
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The attached patch changes the key implementation in a number of ways:
(1) It removes the spinlock from the key structure.
(2) The key flags are now accessed using atomic bitops instead of
write-locking the key spinlock and using C bitwise operators.
The three instantiation flags are dealt with with the construction
semaphore held during the request_key/instantiate/negate sequence, thus
rendering the spinlock superfluous.
The key flags are also now bit numbers not bit masks.
(3) The key payload is now accessed using RCU. This permits the recursive
keyring search algorithm to be simplified greatly since no locks need be
taken other than the usual RCU preemption disablement. Searching now does
not require any locks or semaphores to be held; merely that the starting
keyring be pinned.
(4) The keyring payload now includes an RCU head so that it can be disposed
of by call_rcu(). This requires that the payload be copied on unlink to
prevent introducing races in copy-down vs search-up.
(5) The user key payload is now a structure with the data following it. It
includes an RCU head like the keyring payload and for the same reason. It
also contains a data length because the data length in the key may be
changed on another CPU whilst an RCU protected read is in progress on the
payload. This would then see the supposed RCU payload and the on-key data
length getting out of sync.
I'm tempted to drop the key's datalen entirely, except that it's used in
conjunction with quota management and so is a little tricky to get rid
of.
(6) Update the keys documentation.
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The seccomp check has to happen when entering the syscall and not when
exiting it or regs->gpr[0] contains garabge during signal handling in
ppc64_rt_sigreturn (this actually might be a bug too, but an orthogonal
one, since we really have to run the check before invoking the syscall and
not after it).
Signed-off-by: Andrea Arcangeli <andrea@cpushare.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Patch from Ben Dooks
Add support for the DM9000 and bring default configuration
up-to-date with the latest 2.6.12 kernel release
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Ben Dooks
Add platform_device information for DM9000 chip(s) on the
Simtec BAST and the VR1000 board.
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Ben Dooks
Remove warning of casting `const char *` to a `char *` type.
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch implements Tom Kelly's Scalable TCP congestion control algorithm
for the modular framework.
The algorithm has some nice scaling properties, and has been used a fair bit
in research, though is known to have significant fairness issues, so it's not
really suitable for general purpose use.
Signed-off-by: John Heffner <jheffner@psc.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
H-TCP is a congestion control algorithm developed at the Hamilton Institute, by
Douglas Leith and Robert Shorten. It is extending the standard Reno algorithm
with mode switching is thus a relatively simple modification.
H-TCP is defined in a layered manner as it is still a research platform. The
basic form includes the modification of beta according to the ratio of maxRTT
to min RTT and the alpha=2*factor*(1-beta) relation, where factor is dependant
on the time since last congestion.
The other layers improve convergence by adding appropriate factors to alpha.
The following patch implements the H-TCP algorithm in it's basic form.
Signed-Off-By: Baruch Even <baruch@ev-en.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
TCP Vegas code modified for the new TCP infrastructure.
Vegas now uses microsecond resolution timestamps for
better estimation of performance over higher speed links.
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
TCP Hybla congestion avoidance.
- "In heterogeneous networks, TCP connections that incorporate a
terrestrial or satellite radio link are greatly disadvantaged with
respect to entirely wired connections, because of their longer round
trip times (RTTs). To cope with this problem, a new TCP proposal, the
TCP Hybla, is presented and discussed in the paper[1]. It stems from an
analytical evaluation of the congestion window dynamics in the TCP
standard versions (Tahoe, Reno, NewReno), which suggests the necessary
modifications to remove the performance dependence on RTT.[...]"[1]
[1]: Carlo Caini, Rosario Firrincieli, "TCP Hybla: a TCP enhancement for
heterogeneous networks",
International Journal of Satellite Communications and Networking
Volume 22, Issue 5 , Pages 547 - 566. September 2004.
Signed-off-by: Daniele Lacamera (root at danielinux.net)net
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Sally Floyd's high speed TCP congestion control.
This is useful for comparison and research.
Signed-off-by: John Heffner <jheffner@psc.edu>
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is the existing 2.6.12 Westwood code moved from tcp_input
to the new congestion framework. A lot of the inline functions
have been eliminated to try and make it clearer.
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
TCP BIC congestion control reworked to use the new congestion control
infrastructure. This version is more up to date than the BIC
code in 2.6.12; it incorporates enhancements from BICTCP 1.1,
to handle low latency links.
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Update the documentation to remove the old sysctl values and
include the new congestion control infrastructure. Includes
changes to tcp.txt by Ian McDonald.
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Enhancement to the tcp_diag interface used by the iproute2 ss command
to report the tcp congestion control being used by a socket.
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Allow TCP to have multiple pluggable congestion control algorithms.
Algorithms are defined by a set of operations and can be built in
or modules. The legacy "new RENO" algorithm is used as a starting
point and fallback.
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
It's a bit strange to see tty_register_ldisc call in modules' exit
functions.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
drivers/usb/media/pwc/pwc-uncompress.c: In function `pwc_decompress':
drivers/usb/media/pwc/pwc-uncompress.c:140: warning: unreachable code at beginning of switch statement
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The current ide-cd driver reports the CDROM speed (as found in
/proc/sys/dev/cdrom/info) as the current speed when loading the driver.
Changing the speed of the cdrom drive (by "eject -x" for instance) doesn't
update the speed reported by the kernel. Updating the info could be
valuable for the user as it's the only way to know if the drive accepted
the request or discarded it. It could even be used to list all the
available speeds of the drive.
The attached patch modifies the ide-cd driver so that after every speed
change request the new speed is updated. Please note that the actual
modification is very little but I had to touch quite a few lines in order
to avoid to pre-declare the sub-functions.
Signed-off-by: Eric Piel <eric.piel@tremplin-utc.net>
Acked-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add note about the soon-to-come removal of verify_area() to
Documentation/feature-removal-schedule.txt.
Signed-off-by: Jesper Juhl <juhl-lkml@dif.dk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
In the upcoming aio_down patch, it is useful to store a private data
pointer in the kiocb's wait_queue. Since we provide our own wake up
function and do not require the task_struct pointer, it makes sense to
convert the task pointer into a generic private pointer.
Signed-off-by: Benjamin LaHaise <benjamin.c.lahaise@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
When do_sync_(read|write) encounters an aio method that makes use of the
retry mechanism, they fail to correctly retry the operation. This fixes
that by adding the appropriate sleep and retry mechanism.
Signed-off-by: Benjamin LaHaise <benjamin.c.lahaise@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The driver plays with waitqueue internals and fails to compile after Ben's
"aio: make wait_queue ->task ->private" patch.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
fs/buffer.c::__block_prepare_write() has broken error recovery. It calls
the get_block() callback with "create = 1" and if that succeeds it
immediately clears buffer_new on the just allocated buffer (which has
buffer_new set).
The bug is that if an error occurs and get_block() returns != 0, we break
from this loop and go into recovery code. This code has this comment:
/* Error case: */
/*
* Zero out any newly allocated blocks to avoid exposing stale
* data. If BH_New is set, we know that the block was newly
* allocated in the above loop.
*/
So the intent is obviously good in that it wants to clear just allocated
and hence not zeroed buffers. However the code recognises allocated
buffers by checking for buffer_new being set.
Unfortunately __block_prepare_write() as discussed above already cleared
buffer_new on all allocated buffers thus no buffers will be cleared during
error recovery and old data will be leaked.
The simplest way I can see to fix this is to make the current recovery code
work by _not_ clearing buffer_new after calling get_block() in
__block_prepare_write().
We cannot safely allow buffer_new buffers to "leak out" of
__block_prepare_write(), thus we simply do a quick loop over the buffers
clearing buffer_new on each of them if it is set just before returning
"success" from __block_prepare_write().
Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This file duplicates <linux/posix_acl_xattr.h>, using slightly different
names.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Kconfig is spitting out massive numbers of errors and so on. This patch
switches arch/sparc/Kconfig to use drivers/Kconfig so those stop.
Signed-off-by: William Irwin <wli@holomorphy.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The following patch removes the f_error field and all checks of f_error.
Trond said:
f_error was introduced for NFS, and made sense when we were guaranteed
always to have a file pointer around when write errors occurred. Since
then, we have (for various reasons) had to introduce the nfs_open_context in
order to track the file read/write state, and it made sense to move our
f_error tracking there too.
Signed-off-by: Christoph Lameter <christoph@lameter.com>
Acked-by: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The HCDP specs (i.e., PCDP revision < 3) allow zero as a default value for
baud rate and data bits. So if firmware doesn't supply them, let
early_serial_console_init() probe for them rather than telling it the baud
rate is zero.
Also, update the URL for the PCDP spec.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch allows block device drivers to convert their ioctl functions to
unlocked_ioctl() like character devices and other subsystems. All
functions that were called with the BKL held before are still used that
way, but I would not be surprised if it could be removed from the ioctl
functions in drivers/block/ioctl.c themselves.
As a side note, I found that compat_blkdev_ioctl() acquires the BKL as
well, which looks like a bug. I have checked that every user of
disk->fops->compat_ioctl() in the current git tree gets the BKL itself, so
it could easily be removed from compat_blkdev_ioctl().
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch is based on work by Carlos O'Donell and Matthew Wilcox. It
introduces/updates the compat_time_t type and uses it for compat siginfo
structures. I have built this on ppc64 and x86_64.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
- make boot-up card recognition more reliable (ie. redo interrogation
always if there is no valid 'card inserted' state) (and yes, i saw it
happening on an o2micro controller that both CB_CBARD and CB_16BITCARD
bits were set at the same time)
- also redo interrogation before probing the ISA interrupts. it's safer
to do the probing with the socket in a clean state.
- make card insert detect more reliable. yenta_get_status() now returns
SS_PENDING as long as the card is not completley inserted and one of the
voltage bits is set. also !CB_CBARD doesn't mean CB_16BITCARD. there is
CB_NOTACARD as well, so make an explicit check for CB_16BITCARD.
- for TI bridges: disable IRQs during power-on. in all-serial and tied
interrupt mode the interrupts are always disabled for single-slot
controllers. for two-slot contollers the disabling is only done when the
other slot is empty. to force disabling there is a new module parameter
now: pwr_irqs_off=Y (which is a regression for working setups. that's
why it's an option, only use when required)
- modparm to disable ISA interrupt probing (isa_probe, defaults to on)
- remove unneeded code/cleanups (ie. merge yenta_events() into
yenta_interrupts())
Signed-off-by: Daniel Ritz <daniel.ritz@gmx.ch>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
include/asm/offset.h is a generated file on x86_64 and mips. Let's add it
to Documentation/dontdiff.
Signed-off-by: Michal Schmidt <xschmi00@stud.feec.vutbr.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
gconfig: only show scrollbars if needed (which is more user friendly):
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
