linux-toradex.git/include/linux/init_task.h, branch v2.6.36-rc5

Merge branch 'for-35' of git://repo.or.cz/linux-kbuild

2010-06-01T15:55:52+00:00

* 'for-35' of git://repo.or.cz/linux-kbuild: (81 commits)
  kbuild: Revert part of e8d400a to resolve a conflict
  kbuild: Fix checking of scm-identifier variable
  gconfig: add support to show hidden options that have prompts
  menuconfig: add support to show hidden options which have prompts
  gconfig: remove show_debug option
  gconfig: remove dbg_print_ptype() and dbg_print_stype()
  kconfig: fix zconfdump()
  kconfig: some small fixes
  add random binaries to .gitignore
  kbuild: Include gen_initramfs_list.sh and the file list in the .d file
  kconfig: recalc symbol value before showing search results
  .gitignore: ignore *.lzo files
  headerdep: perlcritic warning
  scripts/Makefile.lib: Align the output of LZO
  kbuild: Generate modules.builtin in make modules_install
  Revert "kbuild: specify absolute paths for cscope"
  kbuild: Do not unnecessarily regenerate modules.builtin
  headers_install: use local file handles
  headers_check: fix perl warnings
  export_report: fix perl warnings
  ...

INIT_SIGHAND: use SIG_DFL instead of NULL

2010-05-27T16:12:52+00:00

Cosmetic, no changes in the compiled code. Just s/NULL/SIG_DFL/ to make
it more readable and grep-friendly.

Note: probably SIG_IGN makes more sense, we could kill ignore_signals().
But then kernel_init() should do flush_signal_handlers() before exec().

Signed-off-by: Oleg Nesterov 
Cc: Cedric Le Goater 
Cc: Dave Hansen 
Cc: Eric Biederman 
Cc: Herbert Poetzl 
Cc: Mathias Krause 
Acked-by: Roland McGrath 
Acked-by: Serge Hallyn 
Cc: Sukadev Bhattiprolu 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

pids: init_struct_pid.tasks should never see the swapper process

2010-05-27T16:12:52+00:00

"statically initialize struct pid for swapper" commit 820e45db says:

	Statically initialize a struct pid for the swapper process (pid_t == 0)
	and attach it to init_task.  This is needed so task_pid(), task_pgrp()
	and task_session() interfaces work on the swapper process also.

OK, but:

	- it doesn't make sense to add init_task.pids[].node into
	  init_struct_pid.tasks[], and in fact this just wrong.

	  idle threads are special, they shouldn't be visible on any
	  global list. In particular do_each_pid_task(init_struct_pid)
	  shouldn't see swapper.

	  This is the actual reason why kill(0, SIGKILL) from /sbin/init
	  (which starts with 0,0 special pids) crashes the kernel. The
	  signal sent to pgid/sid == 0 must never see idle threads, even
	  if the previous patch fixed the crash itself.

	- we have other idle threads running on the non-boot CPUs, see
	  the next patch.

Change INIT_STRUCT_PID/INIT_PID_LINK to create the empty/unhashed
hlist_head/hlist_node. Like any other idle thread swapper can never exit,
so detach_pid()->__hlist_del() is not possible, but we could change
INIT_PID_LINK() to set pprev = &next if needed.

All we need is the valid swapper->pids[].pid == &init_struct_pid.

Reported-by: Mathias Krause 
Signed-off-by: Oleg Nesterov 
Cc: Cedric Le Goater 
Cc: Dave Hansen 
Cc: Eric Biederman 
Cc: Herbert Poetzl 
Cc: Mathias Krause 
Acked-by: Roland McGrath 
Acked-by: Serge Hallyn 
Cc: Sukadev Bhattiprolu 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

INIT_TASK() should initialize ->thread_group list

2010-05-27T16:12:51+00:00

The trivial /sbin/init doing

	int main(void)
	{
		kill(0, SIGKILL)
	}

crashes the kernel.

This happens because __kill_pgrp_info(init_struct_pid) also sends SIGKILL
to the swapper process which runs with the uninitialized ->thread_group.

Change INIT_TASK() to initialize ->thread_group properly.

Note: the real problem is that the swapper process must not be visible to
signals, see the next patch. But this change is right anyway and fixes
the crash.

Reported-and-tested-by: Mathias Krause 
Signed-off-by: Oleg Nesterov 
Cc: Cedric Le Goater 
Cc: Dave Hansen 
Cc: Eric Biederman 
Cc: Herbert Poetzl 
Cc: Mathias Krause 
Acked-by: Roland McGrath 
Acked-by: Serge Hallyn 
Acked-by: Sukadev Bhattiprolu 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

proc: turn signal_struct->count into "int nr_threads"

2010-05-27T16:12:47+00:00

No functional changes, just s/atomic_t count/int nr_threads/.

With the recent changes this counter has a single user, get_nr_threads()
And, none of its callers need the really accurate number of threads, not
to mention each caller obviously races with fork/exit.  It is only used to
report this value to the user-space, except first_tid() uses it to avoid
the unnecessary while_each_thread() loop in the unlikely case.

It is a bit sad we need a word in struct signal_struct for this, perhaps
we can change get_nr_threads() to approximate the number of threads using
signal->live and kill ->nr_threads later.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Oleg Nesterov 
Cc: Alexey Dobriyan 
Cc: "Eric W. Biederman" 
Acked-by: Roland McGrath 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

rcu: remove all rcu head initializations, except on_stack initializations

2010-05-11T23:10:47+00:00

Remove all rcu head inits. We don't care about the RCU head state before passing
it to call_rcu() anyway. Only leave the "on_stack" variants so debugobjects can
keep track of objects on stack.

Signed-off-by: Mathieu Desnoyers 
Signed-off-by: Paul E. McKenney

nsproxy: remove INIT_NSPROXY()

2010-03-12T23:52:40+00:00

Remove INIT_NSPROXY(), use C99 initializer.
Remove INIT_IPC_NS(), INIT_NET_NS() while I'm at it.

Note: headers trim will be done later, now it's quite pointless because
results will be invalidated by merge window.

Signed-off-by: Alexey Dobriyan 
Acked-by: Serge Hallyn 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Rename .data.init_task to .data..init_task.

2010-03-03T10:25:58+00:00

Signed-off-by: Tim Abbott 
Cc: Sam Ravnborg 
Signed-off-by: Denys Vlasenko 
Signed-off-by: Michal Marek

Revert "task_struct: make journal_info conditional"

2009-12-17T21:23:24+00:00

This reverts commit e4c570c4cb7a95dbfafa3d016d2739bf3fdfe319, as
requested by Alexey:

 "I think I gave a good enough arguments to not merge it.
  To iterate:
   * patch makes impossible to start using ext3 on EXT3_FS=n kernels
     without reboot.
   * this is done only for one pointer on task_struct"

  None of config options which define task_struct are tristate directly
  or effectively."

Requested-by: Alexey Dobriyan 
Acked-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branch 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

2009-12-15T17:02:01+00:00

* 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (26 commits)
  clockevents: Convert to raw_spinlock
  clockevents: Make tick_device_lock static
  debugobjects: Convert to raw_spinlocks
  perf_event: Convert to raw_spinlock
  hrtimers: Convert to raw_spinlocks
  genirq: Convert irq_desc.lock to raw_spinlock
  smp: Convert smplocks to raw_spinlocks
  rtmutes: Convert rtmutex.lock to raw_spinlock
  sched: Convert pi_lock to raw_spinlock
  sched: Convert cpupri lock to raw_spinlock
  sched: Convert rt_runtime_lock to raw_spinlock
  sched: Convert rq->lock to raw_spinlock
  plist: Make plist debugging raw_spinlock aware
  bkl: Fixup core_lock fallout
  locking: Cleanup the name space completely
  locking: Further name space cleanups
  alpha: Fix fallout from locking changes
  locking: Implement new raw_spinlock
  locking: Convert raw_rwlock functions to arch_rwlock
  locking: Convert raw_rwlock to arch_rwlock
  ...