Commit graph

95201 commits

Author SHA1 Message Date
Jiri Slaby
bb9f910a11 Char: moxa, notify about board readiness
Drop a message to dmesg about card being ready.

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 08:29:43 -07:00
Jiri Slaby
08d01c7925 Char: moxa, introduce MOXA_IS_320 macro
It allows to simplify the code, especially MoxaPortSetBaud.

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 08:29:43 -07:00
Jiri Slaby
92d30a9372 Char: moxa, remove useless tty functions
- moxa_flush_chars -- no code; ldics handle this well
- moxa_put_char -- only wrapper to moxa_write (same code), tty does this
  the same way if tty->driver->put_char is NULL

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 08:29:43 -07:00
Jiri Slaby
eaa95a8da6 Char: moxa, little cleanup
Cleanup of
- whitespace
- macros
- useless casts
- return (sth); -> return sth;
- types
- superfluous parenthesis and braces
- init tmp directly in moxa_get_serial_info
- commented defunct code
- commented prototypes
- MOXA/moxa printk case

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 08:29:43 -07:00
Jiri Slaby
a8f5cda067 Char: moxa, rework open/close
- add locking to open/close/hangup and ioctl (tiocm)
- add pci hot-un-plug support (hangup on board remove, wait for openers)
- cleanup block_till_ready
- move close code common to close/hangup into separate function to be
  able to call it from open when hangup occurs while block_till_ready
- let ldisc flush on tty layer, it will do it after we return

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 08:29:43 -07:00
Jiri Slaby
2a5413416b Char: moxa, serialise timer
- del timer after we are sure it won't be fired again
- make timer scheduling atomic
- don't reschedule timer when all cards have gone

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 08:29:43 -07:00
Jiri Slaby
2108eba5c5 Char: moxa, cleanup rx/tx
- cleanup types
- use tty_prepare_flip_string and io memcpys

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 08:29:43 -07:00
Jiri Slaby
7bcf97d1dd Char: moxa, merge 2 poll functions
- merge 2 timers into one -- one can handle the emptywait as good as the other
- merge 2 separated poll functions into one, this allows handle the actions
  directly and simplifies the code

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 08:29:43 -07:00
Jiri Slaby
74d7d97b9e Char: moxa, ioctl cleanup
- allow stats only for sys_admin
- move TCSBRK* processing to .break_ctl tty op
- let TIOCGSOFTCAR and TIOCSSOFTCAR be processed by ldisc
- remove MOXA_GET_MAJOR, MOXA_GET_CUMAJOR
- fix jiffies subtraction by time_after
- move moxa ioctl numbers into the header; still not exported to userspace,
  needs _IOC and 32/64 compat cleanup anyways

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
0bcc4caadc Char: moxa, timer cleanup
- schedule timer even after some card is installed, not after insmod
- cleanup timer functions

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
810ab09b2f Char: moxa, centralize board readiness
The only relevant sign of port being ready is its board->ready since now.
Remove all other flags for this purpose which are set almost on the same
place.  Move ports inside the board to be sure that nobody will grab reference
to the port without being sure that it exists.

[jirislaby@gmail.com: fix unused var warning]
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Tested-by: Oyvind Aabling <Oyvind.Aabling@uni-c.dk>
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 08:29:42 -07:00
Jiri Slaby
97506056bd Char: moxa, remove unused port entries
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
b4173f4575 Char: moxa, remove port->port
We don't need to hold a reference to port index.  In most cases we need port
structure anyway and index is available in port->tty->index.

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
5292bcd38e Char: moxa, merge c2xx and c320 firmware loading
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
037182346f Char: moxa, add firmware loading
Substitute ioctl load firmware interface by kernel firmware api.

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
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