Commit Graph

24694 Commits

Author SHA1 Message Date
Jeff Garzik
8b316a3973 [libata] ahci: add ATI SB600 PCI IDs
From: Anatoli Antonovitch <antonovi@ati.com>

Signed-off-by: Felix Kuehling <fkuehlin@ati.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-03-30 17:07:32 -05:00
Jeff Garzik
55d8ca4f80 Merge branch 'mv-merge'
Conflicts:

	drivers/scsi/sata_mv.c
2006-03-29 19:43:31 -05:00
Mark Lord
63af2a5c59 [PATCH] sata_mv: three bug fixes
(1) A DMA transfer size of 0x10000 was not being written
as 0x0000 in the PRDs.  Fixed.

(1) The DEV_IRQ interrupt cause bit happens spuriously
during EDMA operation, and was not being ignored by the driver.
This led to various "drive busy" errors being reported,
with associated unpredictable behaviour.  Fixed.

(2) If a SATA or PCI interrupt was received with no outstanding
command, the interrupt handler still attempted to invoke
ata_qc_complete(), triggering assert()/BUG_ON() behaviour
elsewhere in libata.  Fixed.

The driver still has issues with confusion after error-recovery,
but should now  be reliable in the absence of drive errors.
I will be looking more into the error-handling bugs next.

Signed-Off-By: Mark Lord <mlord@pobox.com>

Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-03-29 19:40:24 -05:00
Albert Lee
00b6f5e9e0 [PATCH] libata: ata_dev_init_params() fixes
ata_dev_init_params() fixes:
- Get the "heads" and "sectors" parameters from caller instead of implicitly from dev->id[].
- Return AC_ERR_INVALID instead of 0 if an invalid parameter is found

Signed-off-by: Albert Lee <albertcc@tw.ibm.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-03-29 19:30:28 -05:00
Alan Cox
17efc5f723 [PATCH] libata: Fix interesting use of "extern" and also some bracketing
Signed-off-by: Alan Cox <alan@redhat.com>

Last of the set, just clean up some oddments. Assuming the whole set is
now ok then the remaining differences are the setup of PIO_0 at reset
and the ->data_xfer method.
Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-03-29 19:30:28 -05:00
Alan Cox
5444a6f405 [PATCH] libata: Simplex and other mode filtering logic
Add a field to the host_set called 'flags' (was host_set_flags changed
to suit Jeff)
Add a simplex_claimed field so we can remember who owns the DMA channel
Add a ->mode_filter() hook to allow drivers to filter modes
Add docs for mode_filter and set_mode
Filter according to simplex state
Filter cable in core

This provides the needed framework to support all the mode rules found
in the PATA world. The simplex filter deals with 'to spec' simplex DMA
systems found in older chips. The cable filter avoids duplicating the
same rules in each chip driver with PATA. Finally the mode filter is
neccessary because drive/chip combinations have errata that forbid
certain modes with some drives or types of ATA object.

Drive speed setup remains per channel for now and the filters now use
the framework Tejun put into place which cleans them up a lot from the
older libata-pata patches.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-03-29 19:30:28 -05:00
Alan Cox
692785e798 [PATCH] libata - ATA is both ATA and CFA
I think this is still needed with the new probe code (which btw seems to
be missing docs in upstream ?).

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-03-29 19:30:28 -05:00
Alan Cox
e35a9e01f2 [PATCH] libata: Add ->set_mode hook for odd drivers
Some hardware doesn't want the usual mode setup logic running. This
allows the hardware driver to replace it for special cases in the least
invasive way possible.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-03-29 19:30:27 -05:00
Alan Cox
4e5ec5dba2 [PATCH] libata: BMDMA handling updates
This is the minimal patch set to enable the current code to be used with
a controller following SFF (ie any PATA and early SATA controllers)
safely without crashes if there is no BMDMA area or if BMDMA is not
assigned by the BIOS for some reason.

Simplex status is recorded but not acted upon in this change, this isn't
a problem with the current drivers as none of them are for simplex
hardware. A following diff will deal with that.

The flags in the probe structure remain ->host_set_flags although Jeff
asked me to rename them, simply because the rename would break the usual
Linux rules that old code should break when there are changes. not
compile and run and then blow up/eat your computer/etc. Renaming this
later is a trivial exercise once a better name is chosen.

Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-03-29 19:30:27 -05:00
Tejun Heo
05c8e0ac5c [PATCH] libata: kill trailing whitespace
Kill trailing whitespace.

Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-03-29 17:19:13 -05:00
Jeff Garzik
e02a4cabfc Merge branch 'master' 2006-03-29 17:18:49 -05:00
Linus Torvalds
f3cab8a0b1 Merge master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
* master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6:
  [NETFILTER]: Rename init functions.
  [TCP]: Fix RFC2465 typo.
  [INET]: Introduce tunnel4/tunnel6
  [NET]: deinline 200+ byte inlines in sock.h
  [ECONET]: Convert away from SOCKOPS_WRAPPED
  [NET]: Fix ipx/econet/appletalk/irda ioctl crashes
  [NET]: Kill Documentation/networking/TODO
  [TG3]: Update version and reldate
  [TG3]: Skip timer code during full lock
  [TG3]: Speed up SRAM access
  [TG3]: Fix PHY loopback on 5700
  [TG3]: Fix bug in 40-bit DMA workaround code
  [TG3]: Fix probe failure due to invalid MAC address
2006-03-29 11:29:33 -08:00
Linus Torvalds
76babde121 Merge git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc
* git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc: (67 commits)
  [PATCH] powerpc: Remove oprofile spinlock backtrace code
  [PATCH] powerpc: Add oprofile calltrace support to all powerpc cpus
  [PATCH] powerpc: Add oprofile calltrace support
  [PATCH] for_each_possible_cpu: ppc
  [PATCH] for_each_possible_cpu: powerpc
  [PATCH] lock PTE before updating it in 440/BookE page fault handler
  [PATCH] powerpc: Kill _machine and hard-coded platform numbers
  ppc: Fix compile error in arch/ppc/lib/strcase.c
  [PATCH] git-powerpc: WARN was a dumb idea
  [PATCH] powerpc: a couple of trivial compile warning fixes
  powerpc: remove OCP references
  powerpc: Make uImage default build output for MPC8540 ADS
  powerpc: move math-emu over to arch/powerpc
  powerpc: use memparse() for mem= command line parsing
  ppc: fix strncasecmp prototype
  [PATCH] powerpc: make ISA floppies work again
  [PATCH] powerpc: Fix some initcall return values
  [PATCH] powerpc: Workaround for pSeries RTAS bug
  [PATCH] spufs: fix __init/__exit annotations
  [PATCH] powerpc: add hvc backend for rtas
  ...
2006-03-29 11:28:30 -08:00
Linus Torvalds
e71ac6032e Merge git://oss.sgi.com:8090/oss/git/xfs-2.6
* git://oss.sgi.com:8090/oss/git/xfs-2.6:
  [XFS] Cleanup in XFS after recent get_block_t interface tweaks.
  [XFS] Remove unused/obsoleted function: xfs_bmap_do_search_extents()
  [XFS] A change to inode chunk allocation to try allocating the new chunk
  Fixes a regression from the recent "remove ->get_blocks() support"
  [XFS] Fix compiler warning and small code inconsistencies in compat
  [XFS] We really suck at spulling.  Thanks to Chris Pascoe for fixing all
2006-03-29 08:55:36 -08:00
Linus Torvalds
224b148ef7 Merge branch 'for-linus' of master.kernel.org:/pub/scm/linux/kernel/git/scjody/ieee1394
* 'for-linus' of master.kernel.org:/pub/scm/linux/kernel/git/scjody/ieee1394:
  ohci1394: cleanup the "Unexpected PCI resource length" warning.
  sbp2: misc debug logging cleanups
  sbp2: proper treatment of DID_OK
  ieee1394: set read permission for parameter disable_irm
  sbp2: check for ARM failure
  ohci1394: clean up asynchronous and physical request filters programming
  ieee1394: remove amdtp remains from ieee1394_core.h
  ieee1394: remove devfs support
  Signed-off-by: Jody McIntyre <scjody@modernduck.com>
  sbp2: prevent unloading of 1394 low-level driver
2006-03-28 18:48:03 -08:00
Anton Blanchard
15e812ad84 [PATCH] powerpc: Remove oprofile spinlock backtrace code
Remove oprofile spinlock backtrace code now we have proper calltrace
support. Also make MMCRA sihv and sipr bits a variable since they may
change in future cpus. Finally, MMCRA should be a 64bit quantity.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-03-29 13:44:16 +11:00
Anton Blanchard
fa465f8c70 [PATCH] powerpc: Add oprofile calltrace support to all powerpc cpus
Add calltrace support for other powerpc cpus. Tested on 7450.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-03-29 13:44:16 +11:00
Brian Rogan
6c6bd754bf [PATCH] powerpc: Add oprofile calltrace support
Add oprofile calltrace support to powerpc. Disable spinlock backtracing
now we can use calltrace info.

(Updated to work on both 32bit and 64bit by me).

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-03-29 13:44:16 +11:00
KAMEZAWA Hiroyuki
b848e0a07d [PATCH] for_each_possible_cpu: ppc
for_each_cpu() actually iterates across all possible CPUs.  We've had mistakes
in the past where people were using for_each_cpu() where they should have been
iterating across only online or present CPUs.  This is inefficient and
possibly buggy.

We're renaming for_each_cpu() to for_each_possible_cpu() to avoid this in the
future.

This patch replaces for_each_cpu with for_each_possible_cpu.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-03-29 13:44:16 +11:00
KAMEZAWA Hiroyuki
0e5519548f [PATCH] for_each_possible_cpu: powerpc
for_each_cpu() actually iterates across all possible CPUs.  We've had mistakes
in the past where people were using for_each_cpu() where they should have been
iterating across only online or present CPUs.  This is inefficient and
possibly buggy.

We're renaming for_each_cpu() to for_each_possible_cpu() to avoid this in the
future.

This patch replaces for_each_cpu with for_each_possible_cpu.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-03-29 13:44:15 +11:00
Eugene Surovegin
bab70a4af7 [PATCH] lock PTE before updating it in 440/BookE page fault handler
Fix 44x and BookE page fault handler to correctly lock PTE before
trying to pte_update() it, otherwise this PTE might be swapped out
after pte_present() check but before pte_uptdate() call, resulting in
corrupted PTE. This can happen with enabled preemption and low memory
condition.

Signed-off-by: Eugene Surovegin <ebs@ebshome.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-03-29 13:44:15 +11:00
Oleg Nesterov
547679087b [PATCH] send_sigqueue: simplify and fix the race
send_sigqueue() checks PF_EXITING, then locks p->sighand->siglock.  This is
unsafe: 'p' can exit in between and set ->sighand = NULL.  The race is
theoretical, the window is tiny and irqs are disabled by the caller, so I
don't think we need the fix for -stable tree.

Convert send_sigqueue() to use lock_task_sighand() helper.

Also, delete 'p->flags & PF_EXITING' re-check, it is unneeded and the
comment is wrong.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-28 18:36:44 -08:00
Oleg Nesterov
a1d5e21e3e [PATCH] do_notify_parent_cldstop: remove 'to_self' param
The previous patch has changed callsites of do_notify_parent_cldstop() so that
to_self == (->ptrace & PT_PTRACED) always (as it should be).  We can remove
this parameter now.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-28 18:36:44 -08:00
Oleg Nesterov
883606a7c9 [PATCH] finish_stop: don't check stop_count < 0
Remove an obscure 'stop_count < 0' check in finish_stop().  The previous patch
made this case impossible.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-28 18:36:44 -08:00
Oleg Nesterov
dac27f4a09 [PATCH] simplify do_signal_stop()
do_signal_stop() considers 'thread_group_empty()' as a special case.
This was needed to avoid taking tasklist_lock. Since this lock is
unneeded any longer, we can remove this special case and simplify
the code even more.

Also, before this patch, finish_stop() was called with stop_count == -1
for 'thread_group_empty()' case. This is not strictly wrong, but confusing
and unneeded.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-28 18:36:44 -08:00
Oleg Nesterov
a7e5328a06 [PATCH] cleanup __exit_signal->cleanup_sighand path
Move 'tsk->sighand = NULL' from cleanup_sighand() to __exit_signal().  This
makes the exit path more understandable and allows us to do
cleanup_sighand() outside of ->siglock protected section.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-28 18:36:44 -08:00
Oleg Nesterov
4a2c7a7837 [PATCH] make fork() atomic wrt pgrp/session signals
Eric W. Biederman wrote:
>
> Ok. SUSV3/Posix is clear, fork is atomic with respect
> to signals.  Either a signal comes before or after a
> fork but not during. (See the rationale section).
> http://www.opengroup.org/onlinepubs/000095399/functions/fork.html
>
> The tasklist_lock does not stop forks from adding to a process
> group. The forks stall while the tasklist_lock is held, but a fork
> that began before we grabbed the tasklist_lock simply completes
> afterwards, and the child does not receive the signal.

This also means that SIGSTOP or sig_kernel_coredump() signal can't
be delivered to pgrp/session reliably.

With this patch copy_process() returns -ERESTARTNOINTR when it
detects a pending signal, fork() will be restarted transparently
after handling the signals.

This patch also deletes now unneeded "group_stop_count > 0" check,
copy_process() can no longer succeed while group stop in progress.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-By: Eric Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-28 18:36:44 -08:00
Oleg Nesterov
47e65328a7 [PATCH] pids: kill PIDTYPE_TGID
This patch kills PIDTYPE_TGID pid_type thus saving one hash table in
kernel/pid.c and speeding up subthreads create/destroy a bit.  It is also a
preparation for the further tref/pids rework.

This patch adds 'struct list_head thread_group' to 'struct task_struct'
instead.

We don't detach group leader from PIDTYPE_PID namespace until another
thread inherits it's ->pid == ->tgid, so we are safe wrt premature
free_pidmap(->tgid) call.

Currently there are no users of find_task_by_pid_type(PIDTYPE_TGID).
Should the need arise, we can use find_task_by_pid()->group_leader.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-By: Eric Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-28 18:36:44 -08:00
Oleg Nesterov
88531f725b [PATCH] do_sigaction: don't take tasklist_lock
do_sigaction() does not need tasklist_lock anymore, we can simplify the code.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-28 18:36:44 -08:00
Oleg Nesterov
aacc90944d [PATCH] do_group_exit: don't take tasklist_lock
do_group_exit() takes tasklist_lock for zap_other_threads(), this is unneeded
now.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-28 18:36:43 -08:00
Oleg Nesterov
a122b341b7 [PATCH] do_signal_stop: don't take tasklist_lock
do_signal_stop() does not need tasklist_lock anymore.  So it does not need to
do misc re-checks, and we can simplify the code.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-28 18:36:43 -08:00
Oleg Nesterov
6108ccd3e2 [PATCH] relax sig_needs_tasklist()
handle_stop_signal() does not need tasklist_lock for SIG_KERNEL_STOP_MASK
signals anymore.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-28 18:36:43 -08:00
Oleg Nesterov
7d7185c818 [PATCH] sys_times: don't take tasklist_lock
sys_times: don't take tasklist_lock

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-28 18:36:43 -08:00
Oleg Nesterov
5876700cd3 [PATCH] do __unhash_process() under ->siglock
This patch moves __unhash_process() call from realease_task() to
__exit_signal(), so __detach_pid() is called with ->siglock held.

This means we don't need tasklist_lock to iterate over thread group anymore:

	copy_process() was already changed to do attach_pid()
	under ->siglock.

	Eric's "pidhash-kill-switch_exec_pids.patch" from -mm
	changed de_thread() so it doesn't touch PIDTYPE_TGID.

NOTE: de_thread() still needs some attention.  It still changes task->pid
lockless.  Taking ->sighand.siglock here allows to do more tasklist_lock
removals.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-28 18:36:43 -08:00
Oleg Nesterov
35f5cad8c4 [PATCH] revert "Optimize sys_times for a single thread process"
This patch reverts 'CONFIG_SMP && thread_group_empty()' optimization in
sys_times().  The reason is that the next patch breaks memory ordering which
is needed for that optimization.

tasklist_lock in sys_times() will be eliminated completely by further patch.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-28 18:36:43 -08:00
Oleg Nesterov
6a14c5c9da [PATCH] move __exit_signal() to kernel/exit.c
__exit_signal() is private to release_task() now.  I think it is better to
make it static in kernel/exit.c and export flush_sigqueue() instead - this
function is much more simple and straightforward.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-28 18:36:43 -08:00
Oleg Nesterov
c81addc9d3 [PATCH] rename __exit_sighand to cleanup_sighand
Cosmetic, rename __exit_sighand to cleanup_sighand and move it close to
copy_sighand().

This matches copy_signal/cleanup_signal naming, and I think it is easier to
follow.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-28 18:36:43 -08:00
Oleg Nesterov
29ff471234 [PATCH] cleanup __exit_signal()
This patch factors out duplicated code under 'if' branches.  Also, BUG_ON()
conversions and whitespace cleanups.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-28 18:36:43 -08:00
Oleg Nesterov
6b3934ef52 [PATCH] copy_process: cleanup bad_fork_cleanup_signal
__exit_signal() does important cleanups atomically under ->siglock.  It is
also called from copy_process's error path.  This is not good, for example we
can't move __unhash_process() under ->siglock for that reason.

We should not mix these 2 paths, just look at ugly 'if (p->sighand)' under
'bad_fork_cleanup_sighand:' label.  For copy_process() case it is sufficient
to just backout copy_signal(), nothing more.

Again, nobody can see this task yet.  For CLONE_THREAD case we just decrement
signal->count, otherwise nobody can see this ->signal and we can free it
lockless.

This patch assumes it is safe to do exit_thread_group_keys() without
tasklist_lock.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-28 18:36:42 -08:00
Oleg Nesterov
7001510d0c [PATCH] copy_process: cleanup bad_fork_cleanup_sighand
The only caller of exit_sighand(tsk) is copy_process's error path.  We can
call __exit_sighand() directly and kill exit_sighand().

This 'tsk' was not yet registered in pid_hash[] or init_task.tasks, it has no
external references, nobody can see it, and

	IF (clone_flags & CLONE_SIGHAND)
		At least 'current' has a reference to ->sighand, this
		means atomic_dec_and_test(sighand->count) can't be true.

	ELSE
		Nobody can see this ->sighand, this means we can free it
		without any locking.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-28 18:36:42 -08:00
Oleg Nesterov
a9e88e84b5 [PATCH] introduce sig_needs_tasklist() helper
In my opinion this patch cleans up the code.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-28 18:36:42 -08:00
Oleg Nesterov
f63ee72e0f [PATCH] introduce lock_task_sighand() helper
Add lock_task_sighand() helper and converts group_send_sig_info() to use
it.  Hopefully we will have more users soon.

This patch also removes '!sighand->count' and '!p->usage' checks, I think
they both are bogus, racy and unneeded (but probably it makes sense to
restore them as BUG_ON()s).

->sighand is cleared and it's ->count is decremented in release_task() with
sighand->siglock held, so it is a bug to have '!p->usage || !->count' after
we already locked and verified it is the same.  On the other hand, an
already dead task without ->sighand can have a non-zero ->usage due to
ptrace, for example.

If we read the stale value of ->sighand we must see the change after
spin_lock(), because that change was done while holding that same old
->sighand.siglock.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-28 18:36:42 -08:00
Oleg Nesterov
aa1757f90b [PATCH] convert sighand_cache to use SLAB_DESTROY_BY_RCU
This patch borrows a clever Hugh's 'struct anon_vma' trick.

Without tasklist_lock held we can't trust task->sighand until we locked it
and re-checked that it is still the same.

But this means we don't need to defer 'kmem_cache_free(sighand)'.  We can
return the memory to slab immediately, all we need is to be sure that
sighand->siglock can't dissapear inside rcu protected section.

To do so we need to initialize ->siglock inside ctor function,
SLAB_DESTROY_BY_RCU does the rest.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-28 18:36:42 -08:00
Oleg Nesterov
1f09f9749c [PATCH] release_task: replace open-coded ptrace_unlink()
Use ptrace_unlink() instead of open-coding.  No changes in kernel/exit.o

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-28 18:36:41 -08:00
Oleg Nesterov
8292d633ad [PATCH] wait_for_helper: trivial style cleanup
Use NULL instead of (... *)0

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-28 18:36:41 -08:00
Oleg Nesterov
6ac781b11a [PATCH] reparent_thread: use remove_parent/add_parent
Use remove_parent/add_parent instead of open coding.

No changes in kernel/exit.o

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-28 18:36:41 -08:00
Oleg Nesterov
c7c6464117 [PATCH] pidhash: don't use zero pids
daemonize() calls set_special_pids(1,1), while init and kernel threads spawned
from init/main.c:init() run with 0,0 special pids.  This patch changes
INIT_SIGNALS() so that that they run with ->pgrp == ->session == 1 also.  This
patch relies on fact that swapper's pid == 1.

Now we have no hashed zero pids in pid_hash[].

User-space visibible change is that now /sbin/init runs with (1,1) special
pids and becomes a session leader.

Quoting Eric W. Biederman:
>
> daemonize consuming pids (1,1) then consumes pgrp 1.  So that when
> /sbin/init calls setsid() it thinks /sbin/init is a process group
> leader and setsid() fails.  So /sbin/init wants pgrp 1 session 1
> but doesn't get it.  I am pretty certain daemonize did not exist so
> /sbin/init got pgrp 1 session 1 in 2.4.
>
> That is the bug that is being fixed.
>
> This patch takes things one step farther and essentially calls
> setsid() for pid == 1 before init is execed.  That is new behavior
> but it cleans up the kernel as we now do not need to support the
> case of a process without a process group or a session.
>
> The only process that could have possibly cared was /sbin/init
> and it already calls setsid() because it doesn't want that.
>
> If this was going to break anything noticeable the change in behavior
> from 2.4 to 2.6 would have already done that.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-28 18:36:41 -08:00
Oleg Nesterov
73b9ebfe12 [PATCH] pidhash: don't count idle threads
fork_idle() does unhash_process() just after copy_process().  Contrary,
boot_cpu's idle thread explicitely registers itself for each pid_type with nr
= 0.

copy_process() already checks p->pid != 0 before process_counts++, I think we
can just skip attach_pid() calls and job control inits for idle threads and
kill unhash_process().  We don't need to cleanup ->proc_dentry in fork_idle()
because with this patch idle threads are never hashed in
kernel/pid.c:pid_hash[].

We don't need to hash pid == 0 in pidmap_init().  free_pidmap() is never
called with pid == 0 arg, so it will never be reused.  So it is still possible
to use pid == 0 in any PIDTYPE_xxx namespace from kernel/pid.c's POV.

However with this patch we don't hash pid == 0 for PIDTYPE_PID case.  We still
have have PIDTYPE_PGID/PIDTYPE_SID entries with pid == 0: /sbin/init and
kernel threads which don't call daemonize().

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-28 18:36:41 -08:00
Oleg Nesterov
c97d98931a [PATCH] kill SET_LINKS/REMOVE_LINKS
Both SET_LINKS() and SET_LINKS/REMOVE_LINKS() have exactly one caller, and
these callers already check thread_group_leader().

This patch kills theese macros, they mix two different things: setting
process's parent and registering it in init_task.tasks list.  Callers are
updated to do these actions by hand.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-28 18:36:41 -08:00
Oleg Nesterov
9b678ece42 [PATCH] don't use REMOVE_LINKS/SET_LINKS for reparenting
There are places where kernel uses REMOVE_LINKS/SET_LINKS while changing
process's ->parent.  Use add_parent/remove_parent instead, they don't abuse
of global process list.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-28 18:36:41 -08:00