Commit Graph

38065 Commits

Author SHA1 Message Date
Eric W. Biederman
558cb32548 [PATCH] pid: add do_each_pid_task
To avoid pid rollover confusion the kernel needs to work with struct pid *
instead of pid_t.  Currently there is not an iterator that walks through all
of the tasks of a given pid type starting with a struct pid.  This prevents us
replacing some pid_t instances with struct pid.  So this patch adds
do_each_pid_task which walks through the set of task for a given pid type
starting with a struct pid.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-02 07:57:13 -07:00
Eric W. Biederman
22c935f47c [PATCH] pid: implement access helpers for a tacks various process groups
In the last round of cleaning up the pid hash table a more general struct pid
was introduced, that can be referenced counted.

With the more general struct pid most if not all places where we store a pid_t
we can now store a struct pid * and remove the need for a hash table lookup,
and avoid any possible problems with pid roll over.

Looking forward to the pid namespaces struct pid * gives us an absolute form a
pid so we can compare and use them without caring which pid namespace we are
in.

This patchset introduces the infrastructure needed to use struct pid instead
of pid_t, and then it goes on to convert two different kernel users that
currently store a pid_t value.

There are a lot more places to go but this is enough to get the basic idea.

Before we can merge a pid namespace patch all of the kernel pid_t users need
to be examined.  Those that deal with user space processes need to be
converted to using a struct pid *.  Those that deal with kernel processes need
to converted to using the kthread api.  A rare few that only use their current
processes pid values get to be left alone.

This patch:

task_session returns the struct pid of a tasks session.
task_pgrp    returns the struct pid of a tasks process group.
task_tgid    returns the struct pid of a tasks thread group.
task_pid     returns the struct pid of a tasks process id.

These can be used to avoid unnecessary hash table lookups, and to implement
safe pid comparisions in the face of a pid namespace.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-02 07:57:13 -07:00
Eric W. Biederman
f6c7a1f34e [PATCH] proc: give the root directory a task
Helper functions in base.c like proc_pident_readdir and proc_pident_lookup
assume the directories have an associated task, and cannot currently be used
on the /proc root directory because it does not have such a task.

This small changes allows for base.c to be simplified and later when multiple
pid spaces are introduced it makes getting the needed context information
trivial.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-02 07:57:13 -07:00
Eric W. Biederman
20cdc894c4 [PATCH] proc: modify proc_pident_lookup to be completely table driven
Currently proc_pident_lookup gets the names and types from a table and then
has a huge switch statement to get the inode and file operations it needs.
That is silly and is becoming increasingly hard to maintain so I just put all
of the information in the table.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-02 07:57:13 -07:00
Eric W. Biederman
28a6d67179 [PATCH] proc: reorder the functions in base.c
There were enough changes in my last round of cleaning up proc I had to break
up the patch series into smaller chunks, and my last chunk never got resent.

This patchset gives proc dynamic inode numbers (the static inode numbers were
a pain to maintain and prevent all kinds of things), and removes the horrible
switch statements that had to be kept in sync with everything else.  Being
fully table driver takes us 90% of the way of being able to register new
process specific attributes in proc.

This patch:

Group the functions by what they implement instead of by type of operation.
As it existed base.c was quickly approaching the point where it could not be
followed.

No functionality or code changes asside from adding/removing forward
declartions are implemented in this patch.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-02 07:57:13 -07:00
Eric W. Biederman
0804ef4b0d [PATCH] proc: readdir race fix (take 3)
The problem: An opendir, readdir, closedir sequence can fail to report
process ids that are continually in use throughout the sequence of system
calls.  For this race to trigger the process that proc_pid_readdir stops at
must exit before readdir is called again.

This can cause ps to fail to report processes, and it is in violation of
posix guarantees and normal application expectations with respect to
readdir.

Currently there is no way to work around this problem in user space short
of providing a gargantuan buffer to user space so the directory read all
happens in on system call.

This patch implements the normal directory semantics for proc, that
guarantee that a directory entry that is neither created nor destroyed
while reading the directory entry will be returned.  For directory that are
either created or destroyed during the readdir you may or may not see them.
 Furthermore you may seek to a directory offset you have previously seen.

These are the guarantee that ext[23] provides and that posix requires, and
more importantly that user space expects.  Plus it is a simple semantic to
implement reliable service.  It is just a matter of calling readdir a
second time if you are wondering if something new has show up.

These better semantics are implemented by scanning through the pids in
numerical order and by making the file offset a pid plus a fixed offset.

The pid scan happens on the pid bitmap, which when you look at it is
remarkably efficient for a brute force algorithm.  Given that a typical
cache line is 64 bytes and thus covers space for 64*8 == 200 pids.  There
are only 40 cache lines for the entire 32K pid space.  A typical system
will have 100 pids or more so this is actually fewer cache lines we have to
look at to scan a linked list, and the worst case of having to scan the
entire pid bitmap is pretty reasonable.

If we need something more efficient we can go to a more efficient data
structure for indexing the pids, but for now what we have should be
sufficient.

In addition this takes no additional locks and is actually less code than
what we are doing now.

Also another very subtle bug in this area has been fixed.  It is possible
to catch a task in the middle of de_thread where a thread is assuming the
thread of it's thread group leader.  This patch carefully handles that case
so if we hit it we don't fail to return the pid, that is undergoing the
de_thread dance.

Thanks to KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> for
providing the first fix, pointing this out and working on it.

[oleg@tv-sign.ru: fix it]
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-02 07:57:12 -07:00
Randy Dunlap
2bc2d61a96 [PATCH] list module taint flags in Oops/panic
When listing loaded modules during an oops or panic, also list each
module's Tainted flags if non-zero (P: Proprietary or F: Forced load only).

If a module is did not taint the kernel, it is just listed like
	usbcore
but if it did taint the kernel, it is listed like
	wizmodem(PF)

Example:
[ 3260.121718] Unable to handle kernel NULL pointer dereference at 0000000000000000 RIP:
[ 3260.121729]  [<ffffffff8804c099>] :dump_test:proc_dump_test+0x99/0xc8
[ 3260.121742] PGD fe8d067 PUD 264a6067 PMD 0
[ 3260.121748] Oops: 0002 [1] SMP
[ 3260.121753] CPU 1
[ 3260.121756] Modules linked in: dump_test(P) snd_pcm_oss snd_mixer_oss snd_seq snd_seq_device ide_cd generic ohci1394 snd_hda_intel snd_hda_codec snd_pcm snd_timer snd ieee1394 snd_page_alloc piix ide_core arcmsr aic79xx scsi_transport_spi usblp
[ 3260.121785] Pid: 5556, comm: bash Tainted: P      2.6.18-git10 #1

[Alternatively, I can look into listing tainted flags with 'lsmod',
but that won't help in oopsen/panics so much.]

[akpm@osdl.org: cleanup]
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-02 07:57:12 -07:00
Dean Nelson
a58cbd7c24 [PATCH] make genpool allocator adhere to kernel-doc standards
The exported kernel interfaces of genpool allocator need to adhere to
the requirements of kernel-doc.

Signed-off-by: Dean Nelson <dcn@sgi.com>
Cc: Steve Wise <swise@opengridcomputing.com>
Acked-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-02 07:57:12 -07:00
Steve Wise
322acc96d4 [PATCH] LIB: add gen_pool_destroy()
Modules using the genpool allocator need to be able to destroy the data
structure when unloading.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Cc: Dean Nelson <dcn@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-02 07:57:12 -07:00
Dave Kleikamp
63f83c9fcf JFS: White space cleanup
Removed trailing spaces & tabs, and spaces preceding tabs.
Also a couple very minor comment cleanups.

Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com>
(cherry picked from f74156539964d7b3d5164fdf8848e6a682f75b97 commit)
2006-10-02 09:55:27 -05:00
Akinobu Mita
087387f90f [PATCH] JFS: return correct error when i-node allocation failed
I have seen confusing behavior on JFS when I injected many intentional
slab allocation errors. The cp command failed with no disk space error
with enough disk space.

This patch makes:

- change the return value in case slab allocation failures happen
  from -ENOSPC to -ENOMEM

- ialloc() return error code so that the caller can know the reason
  of failures

Signed-off-by: Akinobu Mita <mita@miraclelinux.com>
Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com>
(cherry picked from 2b46f77976f798f3fe800809a1d0ed38763c71c8 commit)
2006-10-02 09:51:01 -05:00
Tony Breeds
2a6968a978 JFS: Remove shadow variable from fs/jfs/jfs_txnmgr.c:xtLog()
Signed-off-by: Tony Breeds <tony@bakeyournoodle.com>
Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com>
(cherry picked from bdc3d9e5af7d9c105be734dd7b5c3f1d9425a15a commit)
2006-10-02 09:50:51 -05:00
Amol Lad
76a5027c37 [MTD] Cleanup of 'ioremap balanced with iounmap for drivers/mtd subsystem'
Updated version of patch, in response to comments from Francois Romieu
<romieu@fr.zoreil.com>

Remove gratuitous casts from iounmap and initialisation of variables.

Signed-off-by: Amol Lad <amol@verismonetworks.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-10-02 09:48:23 +01:00
Frederik Deweerdt
553a801208 [MTD] fix nftl_write warning
Building 2.6.18-mm2 issues the following warning if CONFIG_NFTL_RW is not set:

  CC [M]  drivers/mtd/nftlcore.o
drivers/mtd/nftlcore.c:183: warning: 'nftl_write' defined but not used
The following patch only compiles nftl_write if CONFIG_NFTL_RW is set.

Signed-off-by: Frederik Deweerdt <frederik.deweerdt@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-10-02 09:42:25 +01:00
Ashutosh Naik
bb0885900d Input: wistron - add support for Acer TravelMate 2424NWXCi
The key mappings are the same as the older Acer TravelMate 240.

Signed-off-by: Ashutosh Naik <ashutosh.naik@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
2006-10-01 22:07:14 -04:00
Reiner Herrmann
cde45f19ca Input: wistron - fix setting up special buttons
If either wifi or bluetooth button has been detected, the code
would break off the loop. But there are laptops that have both
types of buttons, so the loop has to continue checking.

Signed-off-by: Reiner Herrmann <reiner@reiner-h.de>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
2006-10-01 21:58:51 -04:00
Yoichi Yuasa
04b314b2c3 [MIPS] Remove unused galileo-boars header files
Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-10-01 23:17:00 +01:00
Yoichi Yuasa
b772da30b4 [MIPS] Rename SERIAL_PORT_DEFNS for EV64120
Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-10-01 23:16:59 +01:00
Yoichi Yuasa
998ec2901a [MIPS] Add UART IRQ number for EV64120
Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-10-01 23:16:59 +01:00
Yoichi Yuasa
b00f3774f2 [MIPS] Remove excite_flash.c
excite_flashtest.c is unused.

Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-10-01 23:16:59 +01:00
Yoichi Yuasa
aa400804e0 [MIPS] Update i8259 resources.
Updated i8259 resources to same as i386.

Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-10-01 23:16:59 +01:00
Atsushi Nemoto
1924600cdb [MIPS] Make unwind_stack() can dig into interrupted context
If the PC was ret_from_irq or ret_from_exception, there will be no
more normal stackframe.  Instead of stopping the unwinding, use PC and
RA saved by an exception handler to continue unwinding into the
interrupted context.  This also simplifies the CONFIG_STACKTRACE code.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-10-01 23:16:59 +01:00
Atsushi Nemoto
23126692e3 [MIPS] Stacktrace build-fix and improvement
Fix build error due to stacktrace API change.  Now save_stack_trace()
tries to save all kernel context, including interrupts and exception.
Also some asm code are changed a bit so that we can detect the end of
current context easily.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-10-01 23:16:58 +01:00
Aurelien Jarno
c8cc9618c5 [MIPS] QEMU: Add support for little endian mips
This very small patch adds support for little endian on the virtual QEMU
mips platform. The status of this platform is the same as the big endian
one, ie it is possible to boot a system with init=/bin/sh.

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-10-01 23:16:58 +01:00
Atsushi Nemoto
c59a0f15be [MIPS] Remove __flush_icache_page
__flash_icache_page is unused, so kill it.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-10-01 23:16:58 +01:00
Atsushi Nemoto
1a6183f2e6 [MIPS] lockdep: update defconfigs
Add those lines to all defconfigs.

CONFIG_LOCKDEP_SUPPORT=y
CONFIG_STACKTRACE_SUPPORT=y
CONFIG_TRACE_IRQFLAGS_SUPPORT=y

This is a patch againt linux-mips.org git tree.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-10-01 23:16:57 +01:00
Atsushi Nemoto
1df0f0ff7e [MIPS] lockdep: Add STACKTRACE_SUPPORT and enable LOCKDEP_SUPPORT
Implement stacktrace interface by using unwind_stack() and enable lockdep
support in Kconfig.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-10-01 23:16:57 +01:00
Atsushi Nemoto
eae6c0da9d [MIPS] lockdep: fix TRACE_IRQFLAGS_SUPPORT
In handle_sys and its variants, we must reload some registers which
might be clobbered by trace_hardirqs_on().
Also we must make sure trace_hardirqs_on() called in kernel level (not
exception level).

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-10-01 23:16:57 +01:00
Linus Torvalds
d834c16516 pccard_store_cis: fix wrong error handling
The test for the error from pcmcia_replace_cis() was incorrect, and
would always trigger (because if an error didn't happen, the "ret" value
would not be zero, it would be the passed-in count).

Reported and debugged by Fabrice Bellet <fabrice@bellet.info>

Rather than just fix the single broken test, make the code in question
use an understandable code-sequence instead, fixing the whole function
to be more readable.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01 13:17:44 -07:00
Andrew Morton
4e9011d50d [PATCH] rtc-sysfs fix
It's not clear how this thinko got through..

Cc: Olaf Hering <olaf@aepfle.de>
Cc: David Brownell <david-b@pacbell.net>
Cc: Alessandro Zummo <alessandro.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01 10:39:01 -07:00
Jeff Garzik
9a29230825 [MTD] fix printk warning
gcc spits out this warning:

drivers/mtd/mtd_blkdevs.c: In function ‘do_blktrans_request’:
drivers/mtd/mtd_blkdevs.c:72: warning: format ‘%ld’ expects type ‘long int’, but argument 2 has type ‘unsigned int’

This could be fixed any number of ways, including use of BUG().
rq_data_dir() only returns 0 or 1, so this entire case is superfluous.
I did the most simple fix.

Signed-off-by: Jeff Garzik <jeff@garzik.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-10-01 17:57:26 +01:00
David Woodhouse
8a84fc15ae Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
Manually resolve conflict in include/mtd/Kbuild

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-10-01 17:55:53 +01:00
Jeff Garzik
2c81fbc4cf [netdrvr] hp100: encapsulate all non-module code
The previous '#ifndef MODULE' block did not cover all the
static-build-only code.  Now it does.

Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-10-01 07:32:20 -04:00
Jeff Garzik
de897881e4 drivers/net/wireless/{airo,ipw2100}: fix error handling bugs
airo:
* fix oops, if !CONFIG_PROC_FS (create_proc_entry always returns NULL)

* handle pci_register_driver() failure.  if it fails, we really do
  want to exit, rather than (as a comment indicates) return success
  because-we-are-a-library.

* #if 0 have_isa_dev variable, which is assigned a value but never used

ipw2100:
* handle sysfs_create_group() failure

* handle driver_create_file() failure

Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-10-01 07:31:09 -04:00
Jeff Garzik
b7a00ecd55 [netdrvr] phy: Fix bugs in error handling
The recent __must_check stuff flagged some error handling bugs.

phy/fixed.c:
* handle device_bind_driver() failure

phy/phy_device.c:
* handle device_bind_driver() failure
* release rwsem upon failure

Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-10-01 07:27:46 -04:00
Linus Torvalds
82965addad Merge master.kernel.org:/pub/scm/linux/kernel/git/davej/agpgart
* master.kernel.org:/pub/scm/linux/kernel/git/davej/agpgart:
  [AGPGART] printk fixups.
  [AGPGART] Use pci_get_slot not pci_find_slot
2006-10-01 00:40:55 -07:00
Linus Torvalds
f0b364a13d Merge master.kernel.org:/pub/scm/linux/kernel/git/davej/cpufreq
* master.kernel.org:/pub/scm/linux/kernel/git/davej/cpufreq:
  [CPUFREQ] Make acpi-cpufreq unsticky again.
  [CPUFREQ] longhaul: remove duplicated code.
  [CPUFREQ] Longhaul - Disable arbiter CLE266
  [CPUFREQ] Fix section mismatch warning
  [CPUFREQ] Fix cut-n-paste bug in suspend printk
2006-10-01 00:40:35 -07:00
Zachary Amsden
5a73fdc5ea [PATCH] Some config.h removals
During tracking down a PAE compile failure, I found that config.h was being
included in a bunch of places in i386 code.  It is no longer necessary, so
drop it.

Signed-off-by: Zachary Amsden <zach@vmware.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01 00:39:34 -07:00
Zachary Amsden
789e6ac0a7 [PATCH] paravirt: update pte hook
Add a pte_update_hook which notifies about pte changes that have been made
without using the set_pte / clear_pte interfaces.  This allows shadow mode
hypervisors which do not trap on page table access to maintain synchronized
shadows.

It also turns out, there was one pte update in PAE mode that wasn't using any
accessor interface at all for setting NX protection.  Considering it is PAE
specific, and the accessor is i386 specific, I didn't want to add a generic
encapsulation of this behavior yet.

Signed-off-by: Zachary Amsden <zach@vmware.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01 00:39:34 -07:00
Zachary Amsden
a93cb055a2 [PATCH] paravirt: remove set pte atomic
Now that ptep_establish has a definition in PAE i386 3-level paging code, the
only paging model which is insane enough to have multi-word hardware PTEs
which are not efficient to set atomically, we can remove the ghost of
set_pte_atomic from other architectures which falesly duplicated it, and
remove all knowledge of it from the generic pgtable code.

set_pte_atomic is now a private pte operator which is specific to i386

Signed-off-by: Zachary Amsden <zach@vmware.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01 00:39:34 -07:00
Zachary Amsden
d6d861e3c9 [PATCH] paravirt: optimize ptep establish for pae
The ptep_establish macro is only used on user-level PTEs, for P->P mapping
changes.  Since these always happen under protection of the pagetable lock,
the strong synchronization of a 64-bit cmpxchg is not needed, in fact, not
even a lock prefix needs to be used.  We can simply instead clear the P-bit,
followed by a normal set.  The write ordering is still important to avoid the
possibility of the TLB snooping a partially written PTE and getting a bad
mapping installed.

Signed-off-by: Zachary Amsden <zach@vmware.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01 00:39:34 -07:00
Zachary Amsden
23002d88be [PATCH] paravirt: kpte flush
Create a new PTE function which combines clearing a kernel PTE with the
subsequent flush.  This allows the two to be easily combined into a single
hypercall or paravirt-op.  More subtly, reverse the order of the flush for
kmap_atomic.  Instead of flushing on establishing a mapping, flush on clearing
a mapping.  This eliminates the possibility of leaving stale kmap entries
which may still have valid TLB mappings.  This is required for direct mode
hypervisors, which need to reprotect all mappings of a given page when
changing the page type from a normal page to a protected page (such as a page
table or descriptor table page).  But it also provides some nicer semantics
for real hardware, by providing extra debug-proofing against using stale
mappings, as well as ensuring that no stale mappings exist when changing the
cacheability attributes of a page, which could lead to cache conflicts when
two different types of mappings exist for the same page.

Signed-off-by: Zachary Amsden <zach@vmware.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01 00:39:34 -07:00
Zachary Amsden
25e4df5bae [PATCH] paravirt: combine flush accessed dirty.patch
Remove ptep_test_and_clear_{dirty|young} from i386, and instead use the
dominating functions, ptep_clear_flush_{dirty|young}.  This allows the TLB
page flush to be contained in the same macro, and allows for an eager
optimization - if reading the PTE initially returned dirty/accessed, we can
assume the fact that no subsequent update to the PTE which cleared accessed /
dirty has occurred, as the only way A/D bits can change without holding the
page table lock is if a remote processor clears them.  This eliminates an
extra branch which came from the generic version of the code, as we know that
no other CPU could have cleared the A/D bit, so the flush will always be
needed.

We still export these two defines, even though we do not actually define
the macros in the i386 code:

 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_DIRTY

The reason for this is that the only use of these functions is within the
generic clear_flush functions, and we want a strong guarantee that there
are no other users of these functions, so we want to prevent the generic
code from defining them for us.

Signed-off-by: Zachary Amsden <zach@vmware.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01 00:39:34 -07:00
Zachary Amsden
6606c3e0da [PATCH] paravirt: lazy mmu mode hooks.patch
Implement lazy MMU update hooks which are SMP safe for both direct and shadow
page tables.  The idea is that PTE updates and page invalidations while in
lazy mode can be batched into a single hypercall.  We use this in VMI for
shadow page table synchronization, and it is a win.  It also can be used by
PPC and for direct page tables on Xen.

For SMP, the enter / leave must happen under protection of the page table
locks for page tables which are being modified.  This is because otherwise,
you end up with stale state in the batched hypercall, which other CPUs can
race ahead of.  Doing this under the protection of the locks guarantees the
synchronization is correct, and also means that spurious faults which are
generated during this window by remote CPUs are properly handled, as the page
fault handler must re-check the PTE under protection of the same lock.

Signed-off-by: Zachary Amsden <zach@vmware.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01 00:39:33 -07:00
Zachary Amsden
9888a1cae3 [PATCH] paravirt: pte clear not present
Change pte_clear_full to a more appropriately named pte_clear_not_present,
allowing optimizations when not-present mapping changes need not be reflected
in the hardware TLB for protected page table modes.  There is also another
case that can use it in the fremap code.

Signed-off-by: Zachary Amsden <zach@vmware.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01 00:39:33 -07:00
Zachary Amsden
3dc9079514 [PATCH] paravirt: remove read hazard from cow
We don't want to read PTEs directly like this after they have been modified,
as a lazy MMU implementation of direct page tables may not have written the
updated PTE back to memory yet.

Signed-off-by: Zachary Amsden <zach@vmware.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01 00:39:33 -07:00
Andrew Morton
bd4c8ce41a [PATCH] invalidate_inode_pages2(): ignore page refcounts
The recent fix to invalidate_inode_pages() (git commit 016eb4a) managed to
unfix invalidate_inode_pages2().

The problem is that various bits of code in the kernel can take transient refs
on pages: the page scanner will do this when inspecting a batch of pages, and
the lru_cache_add() batching pagevecs also hold a ref.

Net result is transient failures in invalidate_inode_pages2().  This affects
NFS directory invalidation (observed) and presumably also block-backed
direct-io (not yet reported).

Fix it by reverting invalidate_inode_pages2() back to the old version which
ignores the page refcounts.

We may come up with something more clever later, but for now we need a 2.6.18
fix for NFS.

Cc: Chuck Lever <cel@citi.umich.edu>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01 00:39:33 -07:00
Andi Kleen
d025c9db7f [PATCH] Support piping into commands in /proc/sys/kernel/core_pattern
Using the infrastructure created in previous patches implement support to
pipe core dumps into programs.

This is done by overloading the existing core_pattern sysctl
with a new syntax:

|program

When the first character of the pattern is a '|' the kernel will instead
threat the rest of the pattern as a command to run.  The core dump will be
written to the standard input of that program instead of to a file.

This is useful for having automatic core dump analysis without filling up
disks.  The program can do some simple analysis and save only a summary of
the core dump.

The core dump proces will run with the privileges and in the name space of
the process that caused the core dump.

I also increased the core pattern size to 128 bytes so that longer command
lines fit.

Most of the changes comes from allowing core dumps without seeks.  They are
fairly straight forward though.

One small incompatibility is that if someone had a core pattern previously
that started with '|' they will get suddenly new behaviour.  I think that's
unlikely to be a real problem though.

Additional background:

> Very nice, do you happen to have a program that can accept this kind of
> input for crash dumps?  I'm guessing that the embedded people will
> really want this functionality.

I had a cheesy demo/prototype.  Basically it wrote the dump to a file again,
ran gdb on it to get a backtrace and wrote the summary to a shared directory.
Then there was a simple CGI script to generate a "top 10" crashes HTML
listing.

Unfortunately this still had the disadvantage to needing full disk space for a
dump except for deleting it afterwards (in fact it was worse because over the
pipe holes didn't work so if you have a holey address map it would require
more space).

Fortunately gdb seems to be happy to handle /proc/pid/fd/xxx input pipes as
cores (at least it worked with zsh's =(cat core) syntax), so it would be
likely possible to do it without temporary space with a simple wrapper that
calls it in the right way.  I ran out of time before doing that though.

The demo prototype scripts weren't very good.  If there is really interest I
can dig them out (they are currently on a laptop disk on the desk with the
laptop itself being in service), but I would recommend to rewrite them for any
serious application of this and fix the disk space problem.

Also to be really useful it should probably find a way to automatically fetch
the debuginfos (I cheated and just installed them in advance).  If nobody else
does it I can probably do the rewrite myself again at some point.

My hope at some point was that desktops would support it in their builtin
crash reporters, but at least the KDE people I talked too seemed to be happy
with their user space only solution.

Alan sayeth:

  I don't believe that piping as such as neccessarily the right model, but
  the ability to intercept and processes core dumps from user space is asked
  for by many enterprise users as well.  They want to know about, capture,
  analyse and process core dumps, often centrally and in automated form.

[akpm@osdl.org: loff_t != unsigned long]
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01 00:39:33 -07:00
Andi Kleen
e239ca5405 [PATCH] Create call_usermodehelper_pipe()
A new member in the ever growing family of call_usermode* functions is
born.  The new call_usermodehelper_pipe() function allows to pipe data to
the stdin of the called user mode progam and behaves otherwise like the
normal call_usermodehelp() (except that it always waits for the child to
finish)

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01 00:39:33 -07:00
Andi Kleen
d6cbd281d1 [PATCH] Some cleanup in the pipe code
Split the big and hard to read do_pipe function into smaller pieces.

This creates new create_write_pipe/free_write_pipe/create_read_pipe
functions.  These functions are made global so that they can be used by
other parts of the kernel.

The resulting code is more generic and easier to read and has cleaner error
handling and less gotos.

[akpm@osdl.org: cleanup]
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01 00:39:33 -07:00