Eliminate the throttling behaviour when the netif receive queue fills
because it behaves badly when using high speed networks under load.
The throttling cause multiple packet drops that cause TCP to go into
slow start mode. The same effective patch has been part of BIC TCP and
H-TCP as well as part of Web100.
The existing code drops 100's of packets when the queue fills;
this changes it to individual packet drop-tail.
Signed-off-by: Stephen Hemmminger <shemminger@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Remove the congestion sensing mechanism from netif_rx, and always
return either full or empty. Almost no driver checks the return value
from netif_rx, and those that do only use it for debug messages.
The original design of netif_rx was to do flow control based on the
receive queue, but NAPI has supplanted this and no driver uses the
feedback.
Signed-off-by: Stephen Hemminger <shemminger@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>
John Heffner [Thu, 23 Jun 2005 19:29:07 +0000 (12:29 -0700)]
[TCP]: Add Scalable TCP congestion control module.
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>
Baruch Even [Thu, 23 Jun 2005 19:28:11 +0000 (12:28 -0700)]
[TCP]: Add H-TCP congestion control module.
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>
Daniele Lacamera [Thu, 23 Jun 2005 19:26:34 +0000 (12:26 -0700)]
[TCP]: Add TCP Hybla congestion control module.
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>
John Heffner [Thu, 23 Jun 2005 19:24:58 +0000 (12:24 -0700)]
[TCP]: Add High Speed TCP congestion control module.
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>
[TCP]: Add TCP Westwood congestion control module.
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>
[TCP]: Update sysctl and congestion control documentation.
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>
[TCP]: Add pluggable congestion control algorithm infrastructure.
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>
Andrew Morton [Thu, 23 Jun 2005 07:10:31 +0000 (00:10 -0700)]
[PATCH] pwc-uncompress warning fix
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>
Eric Piel [Thu, 23 Jun 2005 07:10:29 +0000 (00:10 -0700)]
[PATCH] IDE CD reports current speed
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>
Benjamin LaHaise [Thu, 23 Jun 2005 07:10:27 +0000 (00:10 -0700)]
[PATCH] aio: make wait_queue ->task ->private
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>
Benjamin LaHaise [Thu, 23 Jun 2005 07:10:27 +0000 (00:10 -0700)]
[PATCH] aio: fix do_sync_(read|write) to properly handle aio retries
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>
[PATCH] Bug in error recovery in fs/buffer.c::__block_prepare_write()
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>
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>
Bjorn Helgaas [Thu, 23 Jun 2005 07:10:16 +0000 (00:10 -0700)]
[PATCH] PCDP: handle tables that don't supply baud rate
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.
Arnd Bergmann [Thu, 23 Jun 2005 07:10:15 +0000 (00:10 -0700)]
[PATCH] block: add unlocked_ioctl support for block devices
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().
Stephen Rothwell [Thu, 23 Jun 2005 07:10:14 +0000 (00:10 -0700)]
[PATCH] compat: introduce compat_time_t
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>
Daniel Ritz [Thu, 23 Jun 2005 07:10:12 +0000 (00:10 -0700)]
[PATCH] yenta TI: turn off interrupts during card power-on #2
- 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>
Manfred Spraul [Thu, 23 Jun 2005 07:10:06 +0000 (00:10 -0700)]
[PATCH] ipcsem: remove superflous decrease variable from sys_semtimedop
Patrick noticed that the initial scan of the semaphore operations logs
decrease and increase operations seperately, but then both cases are or'ed
together and decrease is never used. The attached patch removes the
decrease parameter - it shrinks sys_semtimedop() by 56 bytes.
Matthias Urlichs [Thu, 23 Jun 2005 07:10:05 +0000 (00:10 -0700)]
[PATCH] Turn off sibling call optimization w/ frame pointers
Frame pointers are supposed to enable debuggers to reliably tell where a
call comes from. That is defeated by GCC's sibling call optimization (aka
tail recursion elimination).
This patch turns this optimization off when compiling with frame pointers.
[PATCH] Optimize sys_times for a single thread process
Avoid taking the tasklist_lock in sys_times if the process is single
threaded. In a NUMA system taking the tasklist_lock may cause a bouncing
cacheline if multiple independent processes continually call sys_times to
measure their performance.
Signed-off-by: Christoph Lameter <christoph@lameter.com> Signed-off-by: Shai Fultheim <shai@scalex86.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Pekka Enberg [Thu, 23 Jun 2005 07:10:03 +0000 (00:10 -0700)]
[PATCH] Remove eventpoll macro obfuscation
This patch gets rid of some macro obfuscation from fs/eventpoll.c by
removing slab allocator wrappers and converting macros to static inline
functions.
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> Acked-by: Davide Libenzi <davidel@xmailserver.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch improves write performance for the CD/DVD packet writing driver.
The logic for switching between reading and writing has been changed so
that streaming writes are no longer interrupted by read requests.
Signed-off-by: Peter Osterlund <petero2@telia.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Jan Beulich [Thu, 23 Jun 2005 07:09:59 +0000 (00:09 -0700)]
[PATCH] adjust per_cpu definition in non-SMP case
Fix (in the architectures I'm actually building for) the UP definition of
per_cpu so that the cpu specified may be any expression, not just an
identifier or a suffix expression.
Signed-off-by: Jan Beulich <jbeulich@novell.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Jan Beulich [Thu, 23 Jun 2005 07:09:59 +0000 (00:09 -0700)]
[PATCH] ide-floppy adjustments
Fix a build problem when IDEFLOPPY_DEBUG_BUGS is turned off, and eliminate an
access to memory that is no longer allocated (causing systems to fail booting
when CONFIG_DEBUG_PAGEALLOC is turned on).
Signed-off-by: Jan Beulich <jbeulich@novell.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Yoav Zach [Thu, 23 Jun 2005 07:09:58 +0000 (00:09 -0700)]
[PATCH] Don't force O_LARGEFILE for 32 bit processes on ia64
In ia64 kernel, the O_LARGEFILE flag is forced when opening a file. This
is problematic for execution of 32 bit processes, which are not largefile
aware, either by SW emulation or by HW execution.
For such processes, the problem is two-fold:
1) When trying to open a file that is larger than 4G
the operation should fail, but it's not
2) Writing to offset larger than 4G should fail, but
it's not
The proposed patch takes advantage of the way 32 bit processes are
identified in ia64 systems. Such processes have PER_LINUX32 for their
personality. With the patch, the ia64 kernel will not enforce the
O_LARGEFILE flag if the current process has PER_LINUX32 set. The behavior
for all other architectures remains unchanged.
Signed-off-by: Yoav Zach <yoav.zach@intel.com> Acked-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Martin Schitter [Thu, 23 Jun 2005 07:09:55 +0000 (00:09 -0700)]
[PATCH] parport: NetMos nm9855 fix
kernel 2.6.12-rc2 adopted some code by Bjorn Helgaas supporting NetMos combo
controller cards. this implementation doesn't work for nm9855 based cards!
there are two reasons:
a) the module 'parport_pc' doesn't want to give the resonsibility for
the netmos_9855 to 'parport_serial' and can not handle the serial lines
-- trivial to fix...
http://lists.infradead.org/pipermail/linux-parport/2005-February/000250.html
http://lkml.org/lkml/2005/3/24/199 b) the support for the nm9855 in
'parport_serial' still doesn't work because of wrong assumptions about
the relevant BARs port address layout for this chip:
0000:00:09.0 Communication controller:
NetMos Technology PCI 9855
Multi-I/O Controller (rev 01)
(= 9710:9855)
Subsystem: LSI Logic / Symbios Logic 1P4S (= 1000:0014)
Flags: medium devsel, IRQ 177
I/O ports at a800 [size=8] (= parport)
I/O ports at a400 [size=8]
I/O ports at a000 [size=8] (= serial)
I/O ports at 9800 [size=8] (= serial)
I/O ports at 9400 [size=8] (= serial)
I/O ports at 9000 [size=16] (= serial)
Kirill Korotaev [Thu, 23 Jun 2005 07:09:54 +0000 (00:09 -0700)]
[PATCH] O(1) sb list traversing on syncs
This patch removes O(n^2) super block loops in sync_inodes(),
sync_filesystems() etc. in favour of using __put_super_and_need_restart()
which I introduced earlier. We faced a noticably long freezes on sb
syncing when there are thousands of super blocks in the system.
Kirill Korotaev [Thu, 23 Jun 2005 07:09:51 +0000 (00:09 -0700)]
[PATCH] Software suspend and recalc sigpending bug fix
This patch fixes recalc_sigpending() to work correctly with tasks which are
being freezed.
The problem is that freeze_processes() sets PF_FREEZE and TIF_SIGPENDING
flags on tasks, but recalc_sigpending() called from e.g.
sys_rt_sigtimedwait or any other kernel place will clear TIF_SIGPENDING due
to no pending signals queued and the tasks won't be freezed until it
recieves a real signal or freezed_processes() fail due to timeout.
In a duplicate of lookup_create in the af_unix code Al commented what's
going on nicely, so let's bring that over to lookup_create before the copy
is going away (I'll send a patch soon)
Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Andreas Dilger [Thu, 23 Jun 2005 07:09:45 +0000 (00:09 -0700)]
[PATCH] Support for dx directories in ext3_get_parent (NFSD)
Henrik Grubbstrom noted:
The 2.6.10 ext3_get_parent attempts to use ext3_find_entry to look up the
entry "..", which fails for dx directories since ".." is not present in the
directory hash table. The patch below solves this by looking up the dotdot
entry in the dx_root block.
Typical symptoms of the above bug are intermittent claims by nfsd that
files or directories are missing on exported ext3 filesystems.
cf https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=3D150759 and
https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=3D144556
ext3_get_parent() is IMHO the wrong place to fix this bug as it introduces
a lot of internals from htree into that function. Instead, I think this
should be fixed in ext3_find_entry() as in the below patch. This has the
added advantage that it works for any callers of ext3_find_entry() and not
just ext3_lookup_parent().
Signed-off-by: Andreas Dilger <adilger@clusterfs.com> Signed-off-by: Henrik Grubbstrom <grubba@grubba.org> Cc: <ext2-devel@lists.sourceforge.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Alan Cox [Thu, 23 Jun 2005 07:09:43 +0000 (00:09 -0700)]
[PATCH] setuid core dump
Add a new `suid_dumpable' sysctl:
This value can be used to query and set the core dump mode for setuid
or otherwise protected/tainted binaries. The modes are
0 - (default) - traditional behaviour. Any process which has changed
privilege levels or is execute only will not be dumped
1 - (debug) - all processes dump core when possible. The core dump is
owned by the current user and no security is applied. This is intended
for system debugging situations only. Ptrace is unchecked.
2 - (suidsafe) - any binary which normally would not be dumped is dumped
readable by root only. This allows the end user to remove such a dump but
not access it directly. For security reasons core dumps in this mode will
not overwrite one another or other files. This mode is appropriate when
adminstrators are attempting to debug problems in a normal environment.
> > if (current->euid == current->uid && current->egid == current->gid)
> > current->mm->dumpable = 1;
>
> Should this be SUID_DUMP_USER?
Actually the feedback I had from last time was that the SUID_ defines
should go because its clearer to follow the numbers. They can go
everywhere (and there are lots of places where dumpable is tested/used
as a bool in untouched code)
> Maybe this should be renamed to `dump_policy' or something. Doing that
> would help us catch any code which isn't using the #defines, too.
Fair comment. The patch was designed to be easy to maintain for Red Hat
rather than for merging. Changing that field would create a gigantic
diff because it is used all over the place.
)
Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
[PATCH] jprobes: allow a jprobe to coexist with muliple kprobes
Presently either multiple kprobes or only one jprobe could be inserted.
This patch removes the above limitation and allows one jprobe and multiple
kprobes to coexist at the same address. However multiple jprobes cannot
coexist with multiple kprobes. Currently I am working on the prototype to
allow multiple jprobes coexist with multiple kprobes.
Signed-off-by: Ananth N Mavinakayanhalli <amavin@redhat.com> Signed-off-by: Prasanna S Panchamukhi <prasanna@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
[PATCH] kprobes: Temporary disarming of reentrant probe
In situations where a kprobes handler calls a routine which has a probe on it,
then kprobes_handler() disarms the new probe forever. This patch removes the
above limitation by temporarily disarming the new probe. When the another
probe hits while handling the old probe, the kprobes_handler() saves previous
kprobes state and handles the new probe without calling the new kprobes
registered handlers. kprobe_post_handler() restores back the previous kprobes
state and the normal execution continues.
However on x86_64 architecture, re-rentrancy is provided only through
pre_handler(). If a routine having probe is referenced through
post_handler(), then the probes on that routine are disarmed forever, since
the exception stack is gets changed after the processor single steps the
instruction of the new probe.
This patch includes generic changes to support temporary disarming on
reentrancy of probes.
Signed-of-by: Prasanna S Panchamukhi <prasanna@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
[PATCH] Kprobes/IA64: check jprobe break before handling
Once the jprobe instrumented function returns, it executes a jprobe_break
which is a break instruction with __IA64_JPROBE_BREAK value. The current
patch checks for this break value, before assuming that jprobe instrumented
function just completed.
The previous code was not checking for this value and that was a bug.
Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The current Kprobes when patching the original instruction with the break
instruction tries to retain the original qualifying predicate(qp), however
for cmp.crel.ctype where ctype == unc, which is a special instruction
always needs to be executed irrespective of qp. Hence, if the instruction
we are patching is of this type, then we should not copy the original qp to
the break instruction, this is because we always want the break fault to
happen so that we can emulate the instruction.
This patch is based on the feedback given by David Mosberger
Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
arch_prepare_kprobes() was doing lots of functionality
in just one single function. This patch
attempts to clean up arch_prepare_kprobes() by moving
specific sub task to the following (new)functions
1)valid_kprobe_addr() -->> validate the given kprobe address
2)get_kprobe_inst(slot..)->> Retrives the instruction for a given slot from the bundle
3)prepare_break_inst() -->> Prepares break instruction within the bundle
3a)update_kprobe_inst_flag()-->>Updates the internal flags, required
for proper emulation of the instruction at later
point in time.
Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Rusty Lynch [Thu, 23 Jun 2005 07:09:30 +0000 (00:09 -0700)]
[PATCH] Kprobes ia64 cleanup
A cleanup of the ia64 kprobes implementation such that all of the bundle
manipulation logic is concentrated in arch_prepare_kprobe().
With the current design for kprobes, the arch specific code only has a
chance to return failure inside the arch_prepare_kprobe() function.
This patch moves all of the work that was happening in arch_copy_kprobe()
and most of the work that was happening in arch_arm_kprobe() into
arch_prepare_kprobe(). By doing this we can add further robustness checks
in arch_arm_kprobe() and refuse to insert kprobes that will cause problems.
Signed-off-by: Rusty Lynch <Rusty.lynch@intel.com> Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
[PATCH] Kprobes/IA64: kdebug die notification mechanism
As many of you know that kprobes exist in the main line kernel for various
architecture including i386, x86_64, ppc64 and sparc64. Attached patches
following this mail are a port of Kprobes and Jprobes for IA64.
I have tesed this patches for kprobes and Jprobes and this seems to work fine.
I have tested this patch by inserting kprobes on various slots and various
templates including various types of branch instructions.
I have also tested this patch using the tool
http://marc.theaimsgroup.com/?l=linux-kernel&m=111657358022586&w=2 and the
kprobes for IA64 works great.
Here is list of TODO things and pathes for the same will appear soon.
1) Support kprobes on "mov r1=ip" type of instruction
2) Support Kprobes and Jprobes to exist on the same address
3) Support Return probes
3) Architecture independent cleanup of kprobes
This patch adds the kdebug die notification mechanism needed by Kprobes.
For break instruction on Branch type slot, imm21 is ignored and value
zero is placed in IIM register, hence we need to handle kprobes
for switch case zero.
At the point in traps.c where we recieve a break with a zero value, we can
not say if the break was a result of a kprobe or some other debug facility.
This simple patch changes the informational string to a more correct "break
0" value, and applies to the 2.6.12-rc2-mm2 tree with all the kprobes
patches that were just recently included for the next mm cut. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Rusty Lynch [Thu, 23 Jun 2005 07:09:25 +0000 (00:09 -0700)]
[PATCH] Move kprobe [dis]arming into arch specific code
The architecture independent code of the current kprobes implementation is
arming and disarming kprobes at registration time. The problem is that the
code is assuming that arming and disarming is a just done by a simple write
of some magic value to an address. This is problematic for ia64 where our
instructions look more like structures, and we can not insert break points
by just doing something like:
*p->addr = BREAKPOINT_INSTRUCTION;
The following patch to 2.6.12-rc4-mm2 adds two new architecture dependent
functions:
and then adds the new functions for each of the architectures that already
implement kprobes (spar64/ppc64/i386/x86_64).
I thought arch_[dis]arm_kprobe was the most descriptive of what was really
happening, but each of the architectures already had a disarm_kprobe()
function that was really a "disarm and do some other clean-up items as
needed when you stumble across a recursive kprobe." So... I took the
liberty of changing the code that was calling disarm_kprobe() to call
arch_disarm_kprobe(), and then do the cleanup in the block of code dealing
with the recursive kprobe case.
So far this patch as been tested on i386, x86_64, and ppc64, but still
needs to be tested in sparc64.
Signed-off-by: Rusty Lynch <rusty.lynch@intel.com> Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Rusty Lynch [Thu, 23 Jun 2005 07:09:23 +0000 (00:09 -0700)]
[PATCH] x86_64 specific function return probes
The following patch adds the x86_64 architecture specific implementation
for function return probes.
Function return probes is a mechanism built on top of kprobes that allows
a caller to register a handler to be called when a given function exits.
For example, to instrument the return path of sys_mkdir:
* At system initialization time, kernel/kprobes.c installs a kprobe
on a function called kretprobe_trampoline() that is implemented in
the arch/x86_64/kernel/kprobes.c (More on this later)
* When a return probe is registered using register_kretprobe(),
kernel/kprobes.c will install a kprobe on the first instruction of the
targeted function with the pre handler set to arch_prepare_kretprobe()
which is implemented in arch/x86_64/kernel/kprobes.c.
* arch_prepare_kretprobe() will prepare a kretprobe instance that stores:
- nodes for hanging this instance in an empty or free list
- a pointer to the return probe
- the original return address
- a pointer to the stack address
With all this stowed away, arch_prepare_kretprobe() then sets the return
address for the targeted function to a special trampoline function called
kretprobe_trampoline() implemented in arch/x86_64/kernel/kprobes.c
* The kprobe completes as normal, with control passing back to the target
function that executes as normal, and eventually returns to our trampoline
function.
* Since a kprobe was installed on kretprobe_trampoline() during system
initialization, control passes back to kprobes via the architecture
specific function trampoline_probe_handler() which will lookup the
instance in an hlist maintained by kernel/kprobes.c, and then call
the handler function.
* When trampoline_probe_handler() is done, the kprobes infrastructure
single steps the original instruction (in this case just a top), and
then calls trampoline_post_handler(). trampoline_post_handler() then
looks up the instance again, puts the instance back on the free list,
and then makes a long jump back to the original return instruction.
So to recap, to instrument the exit path of a function this implementation
will cause four interruptions:
- A breakpoint at the very beginning of the function allowing us to
switch out the return address
- A single step interruption to execute the original instruction that
we replaced with the break instruction (normal kprobe flow)
- A breakpoint in the trampoline function where our instrumented function
returned to
- A single step interruption to execute the original instruction that
we replaced with the break instruction (normal kprobe flow)
Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Hien Nguyen [Thu, 23 Jun 2005 07:09:19 +0000 (00:09 -0700)]
[PATCH] kprobes: function-return probes
This patch adds function-return probes to kprobes for the i386
architecture. This enables you to establish a handler to be run when a
function returns.
1. API
Two new functions are added to kprobes:
int register_kretprobe(struct kretprobe *rp);
void unregister_kretprobe(struct kretprobe *rp);
2. Registration and unregistration
2.1 Register
To register a function-return probe, the user populates the following
fields in a kretprobe object and calls register_kretprobe() with the
kretprobe address as an argument:
kp.addr - the function's address
handler - this function is run after the ret instruction executes, but
before control returns to the return address in the caller.
maxactive - The maximum number of instances of the probed function that
can be active concurrently. For example, if the function is non-
recursive and is called with a spinlock or mutex held, maxactive = 1
should be enough. If the function is non-recursive and can never
relinquish the CPU (e.g., via a semaphore or preemption), NR_CPUS should
be enough. maxactive is used to determine how many kretprobe_instance
objects to allocate for this particular probed function. If maxactive <=
0, it is set to a default value (if CONFIG_PREEMPT maxactive=max(10, 2 *
NR_CPUS) else maxactive=NR_CPUS)
For example:
struct kretprobe rp;
rp.kp.addr = /* entrypoint address */
rp.handler = /*return probe handler */
rp.maxactive = /* e.g., 1 or NR_CPUS or 0, see the above explanation */
register_kretprobe(&rp);
The following field may also be of interest:
nmissed - Initialized to zero when the function-return probe is
registered, and incremented every time the probed function is entered but
there is no kretprobe_instance object available for establishing the
function-return probe (i.e., because maxactive was set too low).
2.2 Unregister
To unregiter a function-return probe, the user calls
unregister_kretprobe() with the same kretprobe object as registered
previously. If a probed function is running when the return probe is
unregistered, the function will return as expected, but the handler won't
be run.
3. Limitations
3.1 This patch supports only the i386 architecture, but patches for
x86_64 and ppc64 are anticipated soon.
3.2 Return probes operates by replacing the return address in the stack
(or in a known register, such as the lr register for ppc). This may
cause __builtin_return_address(0), when invoked from the return-probed
function, to return the address of the return-probes trampoline.
3.3 This implementation uses the "Multiprobes at an address" feature in
2.6.12-rc3-mm3.
3.4 Due to a limitation in multi-probes, you cannot currently establish
a return probe and a jprobe on the same function. A patch to remove
this limitation is being tested.
This feature is required by SystemTap (http://sourceware.org/systemtap),
and reflects ideas contributed by several SystemTap developers, including
Will Cohen and Ananth Mavinakayanahalli.
Signed-off-by: Hien Nguyen <hien@us.ibm.com> Signed-off-by: Prasanna S Panchamukhi <prasanna@in.ibm.com> Signed-off-by: Frederik Deweerdt <frederik.deweerdt@laposte.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
[PATCH] quota: sanitize dentry handling in vfs_quota_on_mount
Use lookup_one_len instead of opencoding a simplified lookup using
lookup_hash with a fake hash.
Also there's no need anymore for the d_invalidate as we have a completely
valid dentry now.
Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Move some code duplicated in both callers into vfs_quota_on_mount
Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Jan Kara <jack@ucw.cz> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Alexander Nyberg [Thu, 23 Jun 2005 07:09:13 +0000 (00:09 -0700)]
[PATCH] avoid resursive oopses
Prevent recursive faults in do_exit() by leaving the task alone and wait
for reboot. This may allow a more graceful shutdown and possibly save the
original oops.
Signed-off-by: Alexander Nyberg <alexn@telia.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
[PATCH] remove duplicate get_dentry functions in various places
Various filesystem drivers have grown a get_dentry() function that's a
duplicate of lookup_one_len, except that it doesn't take a maximum length
argument and doesn't check for \0 or / in the passed in filename.
Switch all these places to use lookup_one_len.
Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Greg KH <greg@kroah.com> Cc: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Neil Horman [Thu, 23 Jun 2005 07:09:11 +0000 (00:09 -0700)]
[PATCH] add check to /proc/devices read routines
Patch to add check to get_chrdev_list and get_blkdev_list to prevent reads
of /proc/devices from spilling over the provided page if more than 4096
bytes of string data are generated from all the registered character and
block devices in a system
Signed-off-by: Neil Horman <nhorman@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: <viro@parcelfarce.linux.theplanet.co.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Jesper Juhl [Thu, 23 Jun 2005 07:09:09 +0000 (00:09 -0700)]
[PATCH] preempt_count is int - remove cast and don't assign to unsigned type
In kernel/sched.c the return value from preempt_count() is cast to an int.
That made sense when preempt_count was defined as different types on is not
needed and should go away. The patch removes the cast.
In kernel/timer.c the return value from preempt_count() is assigned to a
variable of type u32 and then that unsigned value is later compared to
preempt_count(). Since preempt_count() returns an int, an int is what
should be used to store its return value. Storing the result in an
unsigned 32bit integer made a tiny bit of sense back when preempt_count was
different types on different archs, but no more - let's not play signed vs
unsigned comparison games when we don't have to. The patch modifies the
code to use an int to hold the value. While I was around that bit of code
I also made two changes to a nearby (related) printk() - I modified it to
specify the loglevel explicitly and also broke the line into a few pieces
to avoid it being longer than 80 chars and clarified the text a bit.
Jesper Juhl [Thu, 23 Jun 2005 07:09:07 +0000 (00:09 -0700)]
[PATCH] streamline preempt_count type across archs
The preempt_count member of struct thread_info is currently either defined
as int, unsigned int or __s32 depending on arch. This patch makes the type
of preempt_count an int on all archs.
Having preempt_count be an unsigned type prevents the catching of
preempt_count < 0 bugs, and using int on some archs and __s32 on others is
not exactely "neat" - much nicer when it's just int all over.
A previous version of this patch was already ACK'ed by Robert Love, and the
only change in this version of the patch compared to the one he ACK'ed is
that this one also makes sure the preempt_count member is consistently
commented.
Nick Piggin [Thu, 23 Jun 2005 07:09:06 +0000 (00:09 -0700)]
[PATCH] optimise loop driver a bit
Looks like locking can be optimised quite a lot. Increase lock widths
slightly so lo_lock is taken fewer times per request. Also it was quite
trivial to cover lo_pending with that lock, and remove the atomic
requirement. This also makes memory ordering explicitly correct, which is
nice (not that I particularly saw any mem ordering bugs).
Test was reading 4 250MB files in parallel on ext2-on-tmpfs filesystem (1K
block size, 4K page size). System is 2 socket Xeon with HT (4 thread).
intel:/home/npiggin# umount /dev/loop0 ; mount /dev/loop0 /mnt/loop ; /usr/bin/time ./mtloop.sh
Greg Edwards [Thu, 23 Jun 2005 07:09:05 +0000 (00:09 -0700)]
[PATCH] CON_CONSDEV bit not set correctly on last console
According to include/linux/console.h, CON_CONSDEV flag should be set on
the last console specified on the boot command line:
86 #define CON_PRINTBUFFER (1)
87 #define CON_CONSDEV (2) /* Last on the command line */
88 #define CON_ENABLED (4)
89 #define CON_BOOT (8)
This does not currently happen if there is more than one console specified
on the boot commandline. Instead, it gets set on the first console on the
command line. This can cause problems for things like kdb that look for
the CON_CONSDEV flag to see if the console is valid.
Additionaly, it doesn't look like CON_CONSDEV is reassigned to the next
preferred console at unregister time if the console being unregistered
currently has that bit set.
in this case, the flags on ttySG console struct will be 0x4 (should be
0x6).
Attached patch against bk fixes both issues for the cases I looked at. It
uses selected_console (which gets incremented for each console specified on
the command line) as the indicator of which console to set CON_CONSDEV on.
When adding the console to the list, if the previous one had CON_CONSDEV
set, it masks it out. Tested on ia64 and x86.
The problem with the current behavior is it breaks overriding the default from
the boot line. In the ia64 case, there may be a global append line defining
console=a in elilo.conf. Then you want to boot your kernel, and want to
override the default by passing console=b on the boot line. elilo constructs
the kernel cmdline by starting with the value of the global append line, then
tacks on whatever else you specify, which puts console=b last.
Code Review / linux-2.6.git / log