* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
Remove two unneeded exports and make two symbols static in fs/mpage.c
Cleanup after commit 585d3bc06f
Trim includes of fdtable.h
Don't crap into descriptor table in binfmt_som
Trim includes in binfmt_elf
Don't mess with descriptor table in load_elf_binary()
Get rid of indirect include of fs_struct.h
New helper - current_umask()
check_unsafe_exec() doesn't care about signal handlers sharing
New locking/refcounting for fs_struct
Take fs_struct handling to new file (fs/fs_struct.c)
Get rid of bumping fs_struct refcount in pivot_root(2)
Kill unsharing fs_struct in __set_personality()
SGI has observed that on large systems, interrupts are not serviced for a
long period of time when waiting for a rwlock. The following patch series
re-enables irqs while waiting for the lock, resembling the code which is
already there for spinlocks.
I only made the ia64 version, because the patch adds some overhead to the
fast path. I assume there is currently no demand to have this for other
architectures, because the systems are not so large. Of course, the
possibility to implement raw_{read|write}_lock_flags for any architecture
is still there.
This patch:
The new macro LOCK_CONTENDED_FLAGS expands to the correct implementation
depending on the config options, so that IRQ's are re-enabled when
possible, but they remain disabled if CONFIG_LOCKDEP is set.
Signed-off-by: Petr Tesarik <ptesarik@suse.cz>
Signed-off-by: Robin Holt <holt@sgi.com>
Cc: <linux-arch@vger.kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
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>
Fix possible loss/corruption of produced subbufs in
relay_subbufs_consumed().
When buf->subbufs_produced wraps around after UINT_MAX and
buf->subbufs_consumed is still < UINT_MAX, the condition
if (buf->subbufs_consumed > buf->subbufs_produced)
will be true even for certain valid values of subbufs_consumed. This may
lead to loss or corruption of produced subbufs.
Signed-off-by: Aravind Srinivasan <raa.aars@gmail.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: Tom Zanussi <zanussi@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The vmcoreinfo_data[] array is not used outside of kernel/kexec.c, and
can therefore become static. This patch adds the relevant keyword to the
definition of the array.
Noticed by sparse.
Signed-off-by: Dmitri Vorobiev <dmitri.vorobiev@movial.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It would be nice to be able to extract the dmesg log from a vmcore file
without needing to keep the debug symbols for the running kernel handy all
the time. We have a facility to do this in /proc/vmcore. This patch adds
the log_buf and log_end symbols to the vmcoreinfo area so that tools (like
makedumpfile) can easily extract the dmesg logs from a vmcore image.
[akpm@linux-foundation.org: several fixes and cleanups]
[akpm@linux-foundation.org: fix unused log_buf_kexec_setup()]
[akpm@linux-foundation.org: build fix]
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Cc: Simon Horman <horms@verge.net.au>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Simon Horman <horms@verge.net.au>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We are wasting 2 words in signal_struct without any reason to implement
task_pgrp_nr() and task_session_nr().
task_session_nr() has no callers since
2e2ba22ea4, we can remove it.
task_pgrp_nr() is still (I believe wrongly) used in fs/autofsX and
fs/coda.
This patch reimplements task_pgrp_nr() via task_pgrp_nr_ns(), and kills
__pgrp/__session and the related helpers.
The change in drivers/char/tty_io.c is cosmetic, but hopefully makes sense
anyway.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Alan Cox <number6@the-village.bc.nu> [tty parts]
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Serge Hallyn <serue@us.ibm.com>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.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>
Inho, the safety rules for vnr/nr_ns helpers are horrible and buggy.
task_pid_nr_ns(task) needs rcu/tasklist depending on task == current.
As for "special" pids, vnr/nr_ns helpers always need rcu. However, if
task != current, they are unsafe even under rcu lock, we can't trust
task->group_leader without the special checks.
And almost every helper has a callsite which needs a fix.
Also, it is a bit annoying that the implementations of, say,
task_pgrp_vnr() and task_pgrp_nr_ns() are not "symmetrical".
This patch introduces the new helper, __task_pid_nr_ns(), which is always
safe to use, and turns all other helpers into the trivial wrappers.
After this I'll send another patch which converts task_tgid_xxx() as well,
they're are a bit special.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Louis Rilling <Louis.Rilling@kerlabs.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.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>
As pointed out by Cedric Le Goater (in response to Alexey's original
comment wrt mqns), ipc_sysctl.c and utsname_sysctl.c are using
CONFIG_PROC_FS, not CONFIG_PROC_SYSCTL, to determine whether to define
the proc_handlers. Change that.
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Acked-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1) lockdep will complain when run_workqueue() performs recursion.
2) The recursive implementation of run_workqueue() means that
flush_workqueue() and its documentation are inconsistent. This may
hide deadlocks and other bugs.
3) The recursion in run_workqueue() will poison cwq->current_work, but
flush_work() and __cancel_work_timer(), etcetera need a reliable
cwq->current_work.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Eric Dumazet <dada1@cosmosbay.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This bug is ancient too. ptrace_untrace() must not resume the task
if the group stop in progress, we should set TASK_STOPPED instead.
Unfortunately, we still have problems here:
- if the process/thread was traced, SIGNAL_STOP_STOPPED
does not necessary means this thread group is stopped.
- ptrace breaks the bookkeeping of ->group_stop_count.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Another ancient bug. Consider this trivial test-case,
int main(void)
{
int pid = fork();
if (pid) {
ptrace(PTRACE_ATTACH, pid, NULL, NULL);
wait(NULL);
ptrace(PTRACE_DETACH, pid, NULL, NULL);
} else {
pause();
printf("WE HAVE A KERNEL BUG!!!\n");
}
return 0;
}
the child must not "escape" for sys_pause(), but it can and this was seen
in practice.
This is because ptrace_detach does:
if (!child->exit_state)
wake_up_process(child);
this wakeup can happen after this child has already restarted sys_pause(),
because it gets another wakeup from ptrace_untrace().
With or without this patch, perhaps sys_pause() needs a fix. But this
wakeup also breaks the SIGNAL_STOP_STOPPED logic in ptrace_untrace().
Remove this wakeup. The caller saw this task in TASK_TRACED state, and
unless it was SIGKILL'ed in between __ptrace_unlink()->ptrace_untrace()
should handle this case correctly. If it was SIGKILL'ed, we don't need to
wakup the dying tracee too.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Jerome Marchand <jmarchan@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
By discussion with Roland.
- Use ->sibling instead of ->ptrace_entry to chain the need to be
release_task'd childs. Nobody else can use ->sibling, this task
is EXIT_DEAD and nobody can find it on its own list.
- rename ptrace_dead to dead_childs.
- Now that we don't have the "parallel" untrace code, change back
reparent_thread() to return void, pass dead_childs as an argument.
Actually, I don't understand why do we notify /sbin/init when we
reparent a zombie, probably it is better to reap it unconditionally.
[akpm@linux-foundation.org: s/childs/children/]
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "Metzger, Markus T" <markus.t.metzger@intel.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>
By discussion with Roland.
- Rename ptrace_exit() to exit_ptrace(), and change it to do all the
necessary work with ->ptraced list by its own.
- Move this code from exit.c to ptrace.c
- Update the comment in ptrace_detach() to explain the rechecking of
the child->ptrace.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "Metzger, Markus T" <markus.t.metzger@intel.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>
If /sbin/init ignores SIGCHLD and we re-parent a zombie, it is leaked.
reparent_thread() does do_notify_parent() which sets ->exit_signal = -1 in
this case. This means that nobody except us can reap it, the detached
task is not visible to do_wait().
Change reparent_thread() to return a boolean (like __pthread_detach) to
indicate that the thread is dead and must be released. Also change
forget_original_parent() to add the child to ptrace_dead list in this
case.
The naming becomes insane, the next patch does the cleanup.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
reparent_thread() uses ptrace_reparented() to check whether this thread is
ptraced, in that case we should not notify the new parent.
But ptrace_reparented() is not exactly correct when the reparented thread
is traced by /sbin/init, because forget_original_parent() has already
changed ->real_parent.
Currently, the only problem is the false notification. But with the next
patch the kernel crash in this (yes, pathological) case.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If task_detached(p) == T, then either
a) p is not the main thread, we will find the group leader on the
->children list.
or
b) p is the group leader but its ->exit_state = EXIT_DEAD. This
can only happen when the last sub-thread has died, but in that case
that thread has already called kill_orphaned_pgrp() from
exit_notify().
In both cases kill_orphaned_pgrp() looks bogus.
Move the task_detached() check up and simplify the code, this is also
right from the "common sense" pov: we should do nothing with the detached
childs, except move them to the new parent's ->children list.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When ptrace_detach() takes tasklist, the tracee can be SIGKILL'ed. If it
has already passed exit_notify() we can leak a zombie, because a) ptracing
disables the auto-reaping logic, and b) ->real_parent was not notified
about the child's death.
ptrace_detach() should follow the ptrace_exit's logic, change the code
accordingly.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Tested-by: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ignoring_children() takes parent->sighand->siglock and checks
k_sigaction[SIGCHLD] atomically. But this buys nothing, we can't get the
"really" wrong result even if we race with sigaction(SIGCHLD). If we read
the "stale" sa_handler/sa_flags we can pretend it was changed right after
the check.
Remove spin_lock(->siglock), and kill "int ign" which caches the result of
ignoring_children() which becomes rather trivial.
Perhaps it makes sense to export this helper, do_notify_parent() can use
it too.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Move the code from __ptrace_detach() to its single caller and kill this
helper.
Also, fix the ->exit_state check, we shouldn't wake up EXIT_DEAD tasks.
Actually, I think task_is_stopped_or_traced() makes more sense, but this
needs another patch.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When sending a signal to a descendant namespace, set ->si_pid to 0 since
the sender does not have a pid in the receiver's namespace.
Note:
- If rt_sigqueueinfo() sets si_code to SI_USER when sending a
signal across a pid namespace boundary, the value in ->si_pid
will be cleared to 0.
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Daniel Lezcano <daniel.lezcano@free.fr>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Normally SIG_DFL signals to global and container-init are dropped early.
But if a signal is blocked when it is posted, we cannot drop the signal
since the receiver may install a handler before unblocking the signal.
Once this signal is queued however, the receiver container-init has no way
of knowing if the signal was sent from an ancestor or descendant
namespace. This patch ensures that contianer-init drops all SIG_DFL
signals in get_signal_to_deliver() except SIGKILL/SIGSTOP.
If SIGSTOP/SIGKILL originate from a descendant of container-init they are
never queued (i.e dropped in sig_ignored() in an earler patch).
If SIGSTOP/SIGKILL originate from parent namespace, the signal is queued
and container-init processes the signal.
IOW, if get_signal_to_deliver() sees a sig_kernel_only() signal for global
or container-init, the signal must have been generated internally or must
have come from an ancestor ns and we process the signal.
Further, the signal_group_exit() check was needed to cover the case of a
multi-threaded init sending SIGKILL to other threads when doing an exit()
or exec(). But since the new sig_kernel_only() check covers the SIGKILL,
the signal_group_exit() check is no longer needed and can be removed.
Finally, now that we have all pieces in place, set SIGNAL_UNKILLABLE for
container-inits.
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Daniel Lezcano <daniel.lezcano@free.fr>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
