Commit Graph

95186 Commits

Author SHA1 Message Date
Jiri Slaby
9e9fc313ff Char: moxa, fix TIOC(G/S)SOFTCAR param
according to ioctl_list, both have int * as a param, not ulong *.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Tested-by: Oyvind Aabling <Oyvind.Aabling@uni-c.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:42 -07:00
Jiri Slaby
e46a5e3ff0 Char: moxa, pci io space fixup
- request region before remapping pci io space
- use ioremap, iounmap istead of iomap interface, because we use
  readX/writeX for accessing this space because of isa support

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Tested-by: Oyvind Aabling <Oyvind.Aabling@uni-c.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:42 -07:00
Jiri Slaby
d353eca4e0 Char: moxa, cleanup module-param passed isa init
Make the code more readable, remap the base address directly.  Describe module
parameters.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Tested-by: Oyvind Aabling <Oyvind.Aabling@uni-c.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:41 -07:00
Jiri Slaby
37794952a6 Char: moxa, remove static isa support
Static ISA field is empty and probably will never be filled in, remove it.
The driver still supports ISA cards passed through module parameter.  This
actually fixes one bug inside the initialization of module-param passed cards
initialization.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Tested-by: Oyvind Aabling <Oyvind.Aabling@uni-c.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:41 -07:00
Dimitri Sivanich
cbacdd9572 SGI Altix mmtimer: allow larger number of timers per node
The purpose of this patch to the SGI Altix specific mmtimer (posix timer)
driver is to allow a virtually infinite number of timers to be set per
node.

Timers will now be kept on a sorted per-node list and a single node-based
hardware comparator is used to trigger the next timer.

[akpm@linux-foundation.org: mark things static]
[akpm@linux-foundation.org: fix warning]
Signed-off-by: Dimitri Sivanich <sivanich@sgi.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:41 -07:00
Alan Cox
d17468c73e tty: drop the BKL for driver/ldisc ioctl methods
Now we have pushed the lock down we can stop wrapping the call with a lock in
the tty layer.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:41 -07:00
Alan Cox
1c2630ccf9 tty_ioctl: soft carrier handling
First cut at moving the soft carrier handling knowledge entirely into the core
code.  One or two drivers still needed to snoop these functions to track
CLOCAL internally.  Instead make TIOCSSOFTCAR generate the same driver calls
as other termios ioctls changing the clocal flag.  This allows us to remove
any driver knowledge and special casing.  Also while we are at it we can fix
the error handling.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:41 -07:00
Alan Cox
0ee9cbb3c7 tty_ioctl: locking for tty_wait_until_sent
This function still depends on the big kernel lock in some cases.  Push
locking into the function ready for removal of the BKL from ioctl call paths.

Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:41 -07:00
Alan Cox
5d0fdf1e01 tty_io: fix remaining pid struct locking
This fixes the last couple of pid struct locking failures I know about.

[oleg@tv-sign.ru: clean up do_task_stat()]
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:40 -07:00
Joe Peterson
575537b324 Resume TTY on SUSP and fix CRNL order in N_TTY line discipline
Refine these behaviors in the N_TTY line discipline:

1) Handle the signal characters consistently when received in a stopped TTY
   so that SUSP (typically ctrl-Z) behaves like INTR and QUIT in resuming a
   stopped TTY.

2) Adjust the order in which the IGNCR/ICRNL/INLCR processing is applied to
   be more logical and consistent with the behavior of other Unix systems.

Signed-off-by: Joe Peterson <joe@skyrush.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:40 -07:00
Alan Cox
47f86834bb redo locking of tty->pgrp
Historically tty->pgrp and friends were pid_t and the code "knew" they were
safe.  The change to pid structs opened up a few races and the removal of the
BKL in places made them quite hittable.  We put tty->pgrp under the ctrl_lock
for the tty.

Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:40 -07:00
Alan Cox
04f378b198 tty: BKL pushdown
- Push the BKL down into the line disciplines
- Switch the tty layer to unlocked_ioctl
- Introduce a new ctrl_lock spin lock for the control bits
- Eliminate much of the lock_kernel use in n_tty
- Prepare to (but don't yet) call the drivers with the lock dropped
  on the paths that historically held the lock

BKL now primarily protects open/close/ldisc change in the tty layer

[jirislaby@gmail.com: a couple of fixes]
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:40 -07:00
Alan Cox
e523844260 serial_core: Prepare for BKL push down
Instead of checking for the BKL in these methods, take it ourselves.  That
avoids propogating it into the serial drivers and we can then fix them later
on.

Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:40 -07:00
Alan Cox
c0754c99a6 68360serial: Note that there isn't any info->mcr locking
Noticed while auditing the code for the BKL elimination project

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:40 -07:00
Alan Cox
6e4d376c66 isdn_tty: Prepare for BKL push down
Three things here
- Remove softcar handler
- Correct termios change detection logic
- Wrap break/ioctl in lock_kernel ready to drop it in the caller

Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Karsten Keil <kkeil@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:40 -07:00
Alan Cox
9cc3c22bf0 vt_ioctl: Prepare for BKL push down
This one could do with some eyeballs on it.  In theory it simply wraps the
ioctl handler in lock/unlock_kernel ready for the lock/unlocks to be pushed
into specific switch values.  To do that means changing the code to return via
a common exit path not all over the place as it does now, hence the big diff

Signed-off-by: Alan Cox <alan@redhat.com>

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:40 -07:00
Alan Cox
dd9a451aad viocons: BKL locking
For some weird reason I can't ascertain (translation "I think its
broken") the viocons driver calls directly into the n_tty ldisc code even
if another ldisc is in use. It'll probably break if you do that but I'm
just fixing the locking and adding a comment that its horked.

Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:40 -07:00
Alan Cox
1f8cabb705 synclink series: Prepare for BKL pushdown
As these are quite complex I've simply pushed the BKL down into the ioctl
handler not tried to do anything neater.

Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Paul Fulghum <paulkf@microgate.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:39 -07:00
Alan Cox
341339e7af sx: prepare for BKL pushdown
Wrap the ioctl handler, and in this case the break handler also in the
BKL. Remove bogus softcar handlers.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:39 -07:00
Alan Cox
f433c65b8a stallion: Prepare for BKL push down
Remove broken softcar functions, wrap ioctl handler in BKL

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:39 -07:00
Alan Cox
b190e178f6 specialix: Prepare for BKL pushdown
Lock the ioctl handlers and remove bogus softcar handling.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:39 -07:00
Alan Cox
638157bc14 serial167: prepare to push BKL down into drivers
Kill the softcar handlers again, wrap the ioctl handler in the BKL

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:39 -07:00
Alan Cox
bdf183aa47 rocket: Prepare for BKL pushdown
Wrap the ioctl code in lock_kernel calls

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:39 -07:00
Alan Cox
eb17455296 riscom8: Prepare for BKL pushdown
Push the locking down into a couple of functions that need it and remove
bogus TIOCG/SSOFTCAR handling

Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:39 -07:00
Alan Cox
9d6d162d49 mxser: prepare for BKL pushdown
Push the BKL down into various internal routines in the driver ready to
remove it from the break, ioctl and other call points.

Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:39 -07:00
Alan Cox
3736113654 isicom: istallion prepare for lock_kernel pushdown
This is an ancient driver so just wrap it in lock_kernel internally and
be done.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:39 -07:00
Alan Cox
1eac494738 isicom: prepare for lock_kernel push down
Again lock the bits we can't trivially prove are safe without the BKL and
remove the broken TIOCS/GSOFTCAR handler.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:39 -07:00
Alan Cox
5a4bc8c1bd esp: lock_kernel push down
Push the BKL down into a few internal bits of code in this driver.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:39 -07:00
Alan Cox
37925e0503 epca: lock_kernel push down
Prepare epca for removing the lock from above. Most of epca is internally
locked so we can trivially push it down to a few bits of code. Drop the TIOCG/SSOFTCAR handling as that is done *properly* with locks by the mid layer.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:38 -07:00
Alan Cox
7b130c0efd cyclades: Prepare for relaxed locking in callers
Basically wrap it in lock_kernel where it is hard to prove the locking is
ok.

Signed-off-by: Alan Cox <alan@redhat.com>
Cc: "John Stoffel" <john@stoffel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:38 -07:00
Alan Cox
e18ce49b5b amiserial: prepare for locking relaxation in caller
Just wrap this one in a lock_kernel. As I understand it there is no M68K
SMP anyway.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:38 -07:00
Oleg Nesterov
00cd5c37af ptrace: permit ptracing of /sbin/init
Afaics, currently there are no kernel problems with ptracing init, it can't
lose SIGNAL_UNKILLABLE flag and be killed/stopped by accident.

The ability to strace/debug init can be very useful if you try to figure out
why it does not work as expected.

However, admin should know what he does, "gdb /sbin/init 1" stops init, it
can't reap orphaned zombies or take care of /etc/inittab until continued.  It
is even possible to crash init (and thus the whole system) if you wish,
ptracer has full control.

See also the long discussion: http://marc.info/?t=120628018600001

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: Roland McGrath <roland@redhat.com>
Acked-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:38 -07:00
Oleg Nesterov
33e9fc7d01 ptrace: ptrace_attach: use send_sig_info() instead force_sig_specific()
Nobody can block/ignore SIGSTOP, no need to use force_sig_specific() in
ptrace_attach.  Use the "regular" send_sig_info().

With this patch stracing of /sbin/init doesn't clear its SIGNAL_UNKILLABLE,
but not that this makes ptracing of init safe.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:38 -07:00
Oleg Nesterov
68cb947866 ptrace: __ptrace_unlink: use the ptrace_reparented() helper
Currently __ptrace_unlink() checks list_empty(->ptrace_list) to figure out
whether the child was reparented.  Change the code to use ptrace_reparented()
to make this check more explicit and consistent.

No functional changes.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:38 -07:00
Oleg Nesterov
53b6f9fbd3 ptrace: introduce ptrace_reparented() helper
Add another trivial helper for the sake of grep.  It also auto-documents the
fact that ->parent != real_parent implies ->ptrace.

No functional changes.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:38 -07:00
Oleg Nesterov
2800d8d19e document de_thread() with exit_notify() connection
Add a couple of small comments, it is not easy to see what this code does.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:38 -07:00
Oleg Nesterov
376e1d2531 reparent_thread: use same_thread_group()
Trivial, use same_thread_group() in reparent_thread().

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:38 -07:00
Oleg Nesterov
d839fd4d2e ptrace: introduce task_detached() helper
exit.c has numerous "->exit_signal == -1" comparisons, this check is subtle
and deserves a helper.  Imho makes the code more parseable for humans.  At
least it's surely more greppable.

Also, a couple of whitespace cleanups. No functional changes.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:38 -07:00
Roland McGrath
5a8da0ea82 signals: x86 TS_RESTORE_SIGMASK
Replace TIF_RESTORE_SIGMASK with TS_RESTORE_SIGMASK and define our own
set_restore_sigmask() function.  This saves the costly SMP-safe set_bit
operation, which we do not need for the sigmask flag since TIF_SIGPENDING
always has to be set too.

Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:37 -07:00
Roland McGrath
f3de272b82 signals: use HAVE_SET_RESTORE_SIGMASK
Change all the #ifdef TIF_RESTORE_SIGMASK conditionals in non-arch code to
#ifdef HAVE_SET_RESTORE_SIGMASK.  If arch code defines it first, the generic
set_restore_sigmask() using TIF_RESTORE_SIGMASK is not defined.

Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:37 -07:00
akpm@linux-foundation.org
49eaeb4bc4 signals: ia64 renumber TIF_RESTORE_SIGMASK
TIF_RESTORE_SIGMASK no longer needs to be in the _TIF_WORK_* masks.
Those low bits are scarce.  Renumber TIF_RESTORE_SIGMASK to free one up.

Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:37 -07:00
Roland McGrath
02a029b325 signals: s390: renumber TIF_RESTORE_SIGMASK
TIF_RESTORE_SIGMASK no longer needs to be in the _TIF_WORK_* masks.  Those low
bits are scarce, and are all used up now.  Renumber TIF_RESTORE_SIGMASK to
free one up.

Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:37 -07:00
Roland McGrath
7648d961fc signals: set_restore_sigmask TIF_SIGPENDING
Set TIF_SIGPENDING in set_restore_sigmask.  This lets arch code take
TIF_RESTORE_SIGMASK out of the set of bits that will be noticed on return to
user mode.  On some machines those bits are scarce, and we can free this
unneeded one up for other uses.

It is probably the case that TIF_SIGPENDING is always set anyway everywhere
set_restore_sigmask() is used.  But this is some cheap paranoia in case there
is an arcane case where it might not be.

Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:37 -07:00
Roland McGrath
4e4c22c711 signals: add set_restore_sigmask
This adds the set_restore_sigmask() inline in <linux/thread_info.h> and
replaces every set_thread_flag(TIF_RESTORE_SIGMASK) with a call to it.  No
change, but abstracts the details of the flag protocol from all the calls.

Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:37 -07:00
Oleg Nesterov
80fe728d59 signals: allow the kernel to actually kill /sbin/init
Currently the buggy /sbin/init hangs if SIGSEGV/etc happens.  The kernel sends
the signal, init dequeues it and ignores, returns from the exception, repeats
the faulting instruction, and so on forever.

Imho, such a behaviour is not good.  I think that the explicit loud death of
the buggy /sbin/init is better than the silent hang.

Change force_sig_info() to clear SIGNAL_UNKILLABLE when the task should be
really killed.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:37 -07:00
Oleg Nesterov
7a5e873f09 signals: de_thread: simplify the ->child_reaper switching
Now that we rely on SIGNAL_UNKILLABLE flag, de_thread() doesn't need the nasty
hack to kill the old ->child_reaper during the mt-exec.

This also means we can avoid taking tasklist_lock around zap_other_threads().

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:37 -07:00
Oleg Nesterov
fae5fa44f1 signals: fix /sbin/init protection from unwanted signals
The global init has a lot of long standing problems with the unhandled fatal
signals.

	- The "is_global_init(current)" check in get_signal_to_deliver()
	  protects only the main thread. Sub-thread can dequee the fatal
	  signal and shutdown the whole thread group except the main thread.
	  If it dequeues SIGSTOP /sbin/init will be stopped, this is not
	  right too. Note that we can't use is_global_init(->group_leader),
	  this breaks exec and this can't solve other problems we have.

	- Even if afterwards ignored, the fatal signals sets SIGNAL_GROUP_EXIT
	  on delivery. This breaks exec, has other bad implications, and this
	  is just wrong.

Introduce the new SIGNAL_UNKILLABLE flag to fix these problems.  It also helps
to solve some other problems addressed by the subsequent patches.

Currently we use this flag for the global init only, but it could also be used
by kthreads and (perhaps) by the sub-namespace inits.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:37 -07:00
Oleg Nesterov
193191035a signals: check_kill_permission: remove tasklist_lock
Now that task_session() can't return a false NULL, check_kill_permission()
doesn't need tasklist_lock.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:37 -07:00
Oleg Nesterov
2e2ba22ea4 signals: check_kill_permission: check session under tasklist_lock
This wasn't documented, but as Atsushi Tsuji pointed out
check_kill_permission() needs tasklist_lock for task_session_nr().  I missed
this fact when removed tasklist from the callers.

Change check_kill_permission() to take tasklist_lock for the SIGCONT case.
Re-order security checks so that we take tasklist_lock only if/when it is
actually needed.  This is a minimal fix for now, tasklist will be removed
later.

Also change the code to use task_session() instead of task_session_nr().

Also, remove the SIGCONT check from cap_task_kill(), it is bogus (and the
whole function is bogus.  Serge, Eric, why it is still alive?).

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: Atsushi Tsuji <a-tsuji@bk.jp.nec.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:37 -07:00
Oleg Nesterov
53c30337f2 signals: send_signal: be paranoid about signalfd_notify()
send_signal() shouldn't call signalfd_notify() if it then fails with -EAGAIN.
Harmless, just a paranoid cleanup.

Also remove the comment.  It is obsolete, signalfd_notify() was simplified and
does a simple wakeup.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: Davide Libenzi <davidel@xmailserver.org>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:36 -07:00