linux/arch
Peter Zijlstra 24ec839c43 [PATCH] tty: ->signal->tty locking
Fix the locking of signal->tty.

Use ->sighand->siglock to protect ->signal->tty; this lock is already used
by most other members of ->signal/->sighand.  And unless we are 'current'
or the tasklist_lock is held we need ->siglock to access ->signal anyway.

(NOTE: sys_unshare() is broken wrt ->sighand locking rules)

Note that tty_mutex is held over tty destruction, so while holding
tty_mutex any tty pointer remains valid.  Otherwise the lifetime of ttys
are governed by their open file handles.  This leaves some holes for tty
access from signal->tty (or any other non file related tty access).

It solves the tty SLAB scribbles we were seeing.

(NOTE: the change from group_send_sig_info to __group_send_sig_info needs to
       be examined by someone familiar with the security framework, I think
       it is safe given the SEND_SIG_PRIV from other __group_send_sig_info
       invocations)

[schwidefsky@de.ibm.com: 3270 fix]
[akpm@osdl.org: various post-viro fixes]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Alan Cox <alan@redhat.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Roland McGrath <roland@redhat.com>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: James Morris <jmorris@namei.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Jan Kara <jack@ucw.cz>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08 08:28:38 -08:00
..
alpha [PATCH] alpha: switch to pci_get API 2006-12-07 08:39:26 -08:00
arm Merge branch 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm 2006-12-07 15:40:39 -08:00
arm26 [PATCH] arm26: replace kmalloc+memset with kzalloc 2006-12-07 08:39:45 -08:00
avr32 [PATCH] Pass struct dev pointer to dma_cache_sync() 2006-12-07 08:39:41 -08:00
cris [PATCH] mm: arch do_page_fault() vs in_atomic() 2006-12-07 08:39:21 -08:00
frv [PATCH] initrd: remove unused false condition for initrd_start 2006-12-07 08:39:38 -08:00
h8300 Merge branch 'for-linus' of git://one.firstfloor.org/home/andi/git/linux-2.6 2006-12-07 08:59:11 -08:00
i386 Merge branch 'for-linus' of git://one.firstfloor.org/home/andi/git/linux-2.6 2006-12-07 08:59:11 -08:00
ia64 Merge branch 'release' of master.kernel.org:/pub/scm/linux/kernel/git/aegl/linux-2.6 2006-12-07 15:39:22 -08:00
m32r [PATCH] m32r: bootloader support for OPSPUT platform 2006-12-08 08:28:37 -08:00
m68k [PATCH] m68k: replace kmalloc+memset with kzalloc 2006-12-07 08:39:29 -08:00
m68knommu Merge branch 'for-linus' of git://one.firstfloor.org/home/andi/git/linux-2.6 2006-12-07 08:59:11 -08:00
mips [PATCH] Pass struct dev pointer to dma_cache_sync() 2006-12-07 08:39:41 -08:00
parisc [PATCH] elf: Always define elf_addr_t in linux/elf.h 2006-12-07 08:39:38 -08:00
powerpc Merge branch 'for-linus' of git://one.firstfloor.org/home/andi/git/linux-2.6 2006-12-07 08:59:11 -08:00
ppc Merge branch 'for-linus' of git://one.firstfloor.org/home/andi/git/linux-2.6 2006-12-07 08:59:11 -08:00
s390 [PATCH] hotplug CPU: clean up hotcpu_notifier() use 2006-12-07 08:39:39 -08:00
sh [PATCH] initrd: remove unused false condition for initrd_start 2006-12-07 08:39:38 -08:00
sh64 [PATCH] initrd: remove unused false condition for initrd_start 2006-12-07 08:39:38 -08:00
sparc Merge branch 'for-linus' of git://one.firstfloor.org/home/andi/git/linux-2.6 2006-12-07 08:59:11 -08:00
sparc64 [PATCH] tty: ->signal->tty locking 2006-12-08 08:28:38 -08:00
um [PATCH] tty: ->signal->tty locking 2006-12-08 08:28:38 -08:00
v850 [PATCH] relocatable kernel: Kallsyms generate relocatable symbols 2006-12-07 02:14:04 +01:00
x86_64 Merge branch 'for-linus' of git://one.firstfloor.org/home/andi/git/linux-2.6 2006-12-07 08:59:11 -08:00
xtensa [PATCH] vmlinux.lds: consolidate initcall sections 2006-10-27 15:34:51 -07:00