alistair23-linux/kernel
Andrey Vagin 66dd34ad31 signal: allow to send any siginfo to itself
The idea is simple.  We need to get the siginfo for each signal on
checkpointing dump, and then return it back on restore.

The first problem is that the kernel doesn't report complete siginfos to
userspace.  In a signal handler the kernel strips SI_CODE from siginfo.
When a siginfo is received from signalfd, it has a different format with
fixed sizes of fields.  The interface of signalfd was extended.  If a
signalfd is created with the flag SFD_RAW, it returns siginfo in a raw
format.

rt_sigqueueinfo looks suitable for restoring signals, but it can't send
siginfo with a positive si_code, because these codes are reserved for
the kernel.  In the real world each person has right to do anything with
himself, so I think a process should able to send any siginfo to itself.

This patch:

The kernel prevents sending of siginfo with positive si_code, because
these codes are reserved for kernel.  I think we can allow a task to
send such a siginfo to itself.  This operation should not be dangerous.

This functionality is required for restoring signals in
checkpoint/restart.

Signed-off-by: Andrey Vagin <avagin@openvz.org>
Cc: Serge Hallyn <serge.hallyn@canonical.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-27 19:10:11 -08:00
..
debug kgdb: remove #include <linux/serial_8250.h> from kgdb.h 2013-02-04 15:35:26 -08:00
events Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
gcov kernel/gcov: remove depends on CONFIG_EXPERIMENTAL 2013-01-11 11:39:33 -08:00
irq Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
power Driver core patches for 3.9-rc1 2013-02-21 12:05:51 -08:00
sched Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-02-26 19:42:08 -08:00
time Merge branch 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-02-22 19:25:09 -08:00
trace Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-02-26 19:40:37 -08:00
.gitignore
acct.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
async.c Merge branch 'for-3.9' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq 2013-02-19 22:01:33 -08:00
audit.c kernel/audit.c: avoid negative sleep durations 2013-01-11 14:54:56 -08:00
audit.h
audit_tree.c audit: catch possible NULL audit buffers 2013-01-11 14:54:55 -08:00
audit_watch.c audit: catch possible NULL audit buffers 2013-01-11 14:54:55 -08:00
auditfilter.c audit: fix auditfilter.c kernel-doc warnings 2013-01-10 14:35:23 -08:00
auditsc.c audit: catch possible NULL audit buffers 2013-01-11 14:54:55 -08:00
backtracetest.c
bounds.c
capability.c
cgroup.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
cgroup_freezer.c cgroup: rename ->create/post_create/pre_destroy/destroy() to ->css_alloc/online/offline/free() 2012-11-19 08:13:38 -08:00
compat.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal 2013-02-23 18:50:11 -08:00
configs.c
context_tracking.c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-02-19 18:19:48 -08:00
cpu.c Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-02-19 19:04:55 -08:00
cpu_pm.c
cpuset.c Merge branch 'for-3.9-cpuset' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2013-02-20 09:18:31 -08:00
crash_dump.c
cred.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2012-12-18 10:55:28 -08:00
delayacct.c cputime: Use accessors to read task cputime stats 2013-01-27 19:23:31 +01:00
dma.c
elfcore.c
exec_domain.c
exit.c cputime: Use accessors to read task cputime stats 2013-01-27 19:23:31 +01:00
extable.c
fork.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
freezer.c
futex.c Merge branch 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-02-22 19:25:09 -08:00
futex_compat.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal 2013-02-23 18:50:11 -08:00
groups.c
hrtimer.c Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-02-19 19:05:45 -08:00
hung_task.c
irq_work.c Merge branch 'nohz/printk-v8' into irq/core 2013-02-05 00:48:46 +01:00
itimer.c
jump_label.c
kallsyms.c
kcmp.c kcmp: include linux/ptrace.h 2012-12-20 17:40:19 -08:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kexec.c x86: Add Crash kernel low reservation 2013-01-29 19:32:58 -08:00
kfifo.c
kmod.c Merge branch 'master' into for-3.9-async 2013-01-23 09:31:01 -08:00
kprobes.c Merge branch 'for-3.9-cleanups' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq 2013-02-19 21:58:52 -08:00
ksysfs.c Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-12-11 18:10:49 -08:00
kthread.c kthread: use N_MEMORY instead N_HIGH_MEMORY 2012-12-12 17:38:33 -08:00
latencytop.c
lglock.c
lockdep.c lockdep: Print more info when MAX_LOCK_DEPTH is exceeded 2013-02-19 08:42:44 +01:00
lockdep_internals.h
lockdep_proc.c
lockdep_states.h
Makefile MODSIGN: Simplify Makefile with a Kconfig helper 2013-01-25 16:55:35 +10:30
modsign_certificate.S MODSIGN: Avoid using .incbin in C source 2012-12-14 13:06:44 +10:30
modsign_pubkey.c keys: use keyring_alloc() to create module signing keyring 2012-12-20 17:40:21 -08:00
module-internal.h
module.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
module_signing.c MODSIGN: Don't use enum-type bitfields in module signature info block 2012-12-05 11:27:24 +10:30
mutex-debug.c
mutex-debug.h
mutex.c sched/rt: Move rt specific bits into new header file 2013-02-07 20:51:08 +01:00
mutex.h
notifier.c
nsproxy.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
padata.c padata: use __this_cpu_read per-cpu helper 2012-12-06 17:16:23 +08:00
panic.c taint: add explicit flag to show whether lock dep is still OK. 2013-01-21 17:17:57 +10:30
params.c
pid.c kernel/pid.c: reenable interrupts when alloc_pid() fails because init has exited 2013-02-12 14:34:00 -08:00
pid_namespace.c pidns: Stop pid allocation when init dies 2012-12-25 16:10:05 -08:00
posix-cpu-timers.c Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-02-19 19:05:45 -08:00
posix-timers.c posix-timer: Don't call idr_find() with out-of-range ID 2013-02-21 17:28:29 +01:00
printk.c Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux 2013-02-25 16:46:44 -08:00
profile.c profiling: Remove unused timer hook 2013-01-24 15:37:26 +01:00
ptrace.c uprobes: Add exports for module use 2013-02-08 17:47:13 +01:00
range.c
rcu.h rcu: Provide RCU CPU stall warnings for tiny RCU 2013-01-28 22:06:21 -08:00
rcupdate.c Merge branches 'doctorture.2013.01.29a', 'fixes.2013.01.26a', 'tagcb.2013.01.24a' and 'tiny.2013.01.29b' into HEAD 2013-01-28 22:25:21 -08:00
rcutiny.c Merge branches 'doctorture.2013.01.29a', 'fixes.2013.01.26a', 'tagcb.2013.01.24a' and 'tiny.2013.01.29b' into HEAD 2013-01-28 22:25:21 -08:00
rcutiny_plugin.h rcu: Provide RCU CPU stall warnings for tiny RCU 2013-01-28 22:06:21 -08:00
rcutorture.c rcu: Allow rcutorture to be built at low optimization levels 2013-02-04 12:18:20 -08:00
rcutree.c Merge branches 'doctorture.2013.01.29a', 'fixes.2013.01.26a', 'tagcb.2013.01.24a' and 'tiny.2013.01.29b' into HEAD 2013-01-28 22:25:21 -08:00
rcutree.h Merge branches 'doctorture.2013.01.29a', 'fixes.2013.01.26a', 'tagcb.2013.01.24a' and 'tiny.2013.01.29b' into HEAD 2013-01-28 22:25:21 -08:00
rcutree_plugin.h rcu: Make rcu_nocb_poll an early_param instead of module_param 2013-01-08 14:12:19 -08:00
rcutree_trace.c rcu: Separate accounting of callbacks from callback-free CPUs 2012-11-16 10:05:57 -08:00
relay.c new helper: file_inode(file) 2013-02-22 23:31:31 -05:00
res_counter.c res_counter: return amount of charges after res_counter_uncharge() 2012-12-18 15:02:12 -08:00
resource.c
rtmutex-debug.c sched/rt: Move rt specific bits into new header file 2013-02-07 20:51:08 +01:00
rtmutex-debug.h
rtmutex-tester.c sched/rt: Move rt specific bits into new header file 2013-02-07 20:51:08 +01:00
rtmutex.c sched/rt: Move rt specific bits into new header file 2013-02-07 20:51:08 +01:00
rtmutex.h
rtmutex_common.h
rwsem.c lockdep, rwsem: provide down_write_nest_lock() 2013-01-11 14:54:55 -08:00
seccomp.c
semaphore.c
signal.c signal: allow to send any siginfo to itself 2013-02-27 19:10:11 -08:00
smp.c smp: make smp_call_function_many() use logic similar to smp_call_function_single() 2013-02-21 17:22:20 -08:00
smpboot.c smpboot: Allow selfparking per cpu threads 2013-02-14 15:29:37 +01:00
smpboot.h
softirq.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2013-02-20 18:58:50 -08:00
spinlock.c
srcu.c srcu: use ACCESS_ONCE() to access sp->completed in srcu_read_lock() 2013-02-07 15:19:36 -08:00
stacktrace.c
stop_machine.c stop_machine: Use smpboot threads 2013-02-14 15:29:38 +01:00
sys.c usermodehelper: cleanup/fix __orderly_poweroff() && argv_free() 2013-02-27 19:10:09 -08:00
sys_ni.c module: add syscall to load module from fd 2012-12-14 13:05:22 +10:30
sysctl.c The sweeping change is to make add_taint() explicitly indicate whether to disable 2013-02-25 15:41:43 -08:00
sysctl_binary.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
task_work.c
taskstats.c
test_kprobes.c
time.c time: don't inline EXPORT_SYMBOL functions 2013-02-21 17:22:19 -08:00
timeconst.pl timeconst.pl: Eliminate Perl warning 2013-02-07 17:14:08 -08:00
timer.c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-02-19 18:19:48 -08:00
tracepoint.c
tsacct.c cputime: Use accessors to read task cputime stats 2013-01-27 19:23:31 +01:00
uid16.c
up.c
user-return-notifier.c
user.c userns: Avoid recursion in put_user_ns 2013-01-26 22:11:41 -08:00
user_namespace.c userns: Allow any uid or gid mappings that don't overlap. 2013-01-26 22:12:04 -08:00
utsname.c userns: Require CAP_SYS_ADMIN for most uses of setns. 2012-12-14 16:12:03 -08:00
utsname_sysctl.c
wait.c propagate name change to comments in kernel source 2012-12-06 10:39:54 +01:00
watchdog.c Merge branch 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-02-22 19:25:09 -08:00
workqueue.c workqueue: un-GPL function delayed_work_timer_fn() 2013-02-19 10:09:13 -08:00
workqueue_internal.h workqueue: rename cpu_workqueue to pool_workqueue 2013-02-13 19:29:12 -08:00