linux/kernel, branch v3.3

prctl: use CAP_SYS_RESOURCE for PR_SET_MM option

2012-03-16T00:03:03Z

CAP_SYS_ADMIN is already overloaded left and right, so to have more fine-grained access control use CAP_SYS_RESOURCE here. The CAP_SYS_RESOUCE is chosen because this prctl option allows a current process to adjust some fields of memory map descriptor which rather represents what the process owns: pointers to code, data, stack segments, command line, auxiliary vector data and etc. Suggested-by: Michael Kerrisk Acked-by: Kees Cook Acked-by: Michael Kerrisk Cc: Pavel Emelyanov Cc: Tejun Heo Cc: Oleg Nesterov Cc: Paul Bolle Cc: KOSAKI Motohiro Signed-off-by: Cyrill Gorcunov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge branch 'for-linus' of git://git.kernel.dk/linux-block

2012-03-15T00:16:45Z

Pull block fixes from Jens Axboe: "Been sitting on this for a while, but lets get this out the door. This fixes various important bugs for 3.3 final, along with a few more trivial ones. Please pull!" * 'for-linus' of git://git.kernel.dk/linux-block: block: fix ioc leak in put_io_context block, sx8: fix pointer math issue getting fw version Block: use a freezable workqueue for disk-event polling drivers/block/DAC960: fix -Wuninitialized warning drivers/block/DAC960: fix DAC960_V2_IOCTL_Opcode_T -Wenum-compare warning block: fix __blkdev_get and add_disk race condition block: Fix setting bio flags in drivers (sd_dif/floppy) block: Fix NULL pointer dereference in sd_revalidate_disk block: exit_io_context() should call elevator_exit_icq_fn() block: simplify ioc_release_fn() block: replace icq->changed with icq->flags

Revert "CPU hotplug, cpusets, suspend: Don't touch cpusets during suspend/resume"

2012-03-07T16:21:19Z

This reverts commit 8f2f748b0656257153bcf0941df8d6060acc5ca6. It causes some odd regression that we have not figured out, and it's too late in the -rc series to try to figure it out now. As reported by Konstantin Khlebnikov, it causes consistent hangs on his laptop (Thinkpad x220: 2x cores + HT). They can be avoided by adding calls to "rebuild_sched_domains();" in cpuset_cpu_[in]active() for the CPU_{ONLINE/DOWN_FAILED/DOWN_PREPARE}_FROZEN cases, but it's not at all clear why, and it makes no sense. Konstantin's config doesn't even have CONFIG_CPUSETS enabled, just to make things even more interesting. So it's not the cpusets, it's just the scheduling domains. So until this is understood, revert. Bisected-reported-and-tested-by: Konstantin Khlebnikov Acked-by: Peter Zijlstra Acked-by: Ingo Molnar Acked-by: Srivatsa S. Bhat Signed-off-by: Linus Torvalds

genirq: Clear action->thread_mask if IRQ_ONESHOT is not set

2012-03-07T00:46:39Z

Xommit ac5637611(genirq: Unmask oneshot irqs when thread was not woken) fails to unmask when a !IRQ_ONESHOT threaded handler is handled by handle_level_irq. This happens because thread_mask is or'ed unconditionally in irq_wake_thread(), but for !IRQ_ONESHOT interrupts never cleared. So the check for !desc->thread_active fails and keeps the interrupt disabled. Keep the thread_mask zero for !IRQ_ONESHOT interrupts. Document the thread_mask magic while at it. Reported-and-tested-by: Sven Joachim Reported-and-tested-by: Stefan Lippers-Hollmann Cc: stable@vger.kernel.org Signed-off-by: Thomas Gleixner Signed-off-by: Linus Torvalds

hung_task: fix the broken rcu_lock_break() logic

2012-03-05T23:49:42Z

check_hung_uninterruptible_tasks()->rcu_lock_break() introduced by "softlockup: check all tasks in hung_task" commit ce9dbe24 looks absolutely wrong. - rcu_lock_break() does put_task_struct(). If the task has exited it is not safe to even read its ->state, nothing protects this task_struct. - The TASK_DEAD checks are wrong too. Contrary to the comment, we can't use it to check if the task was unhashed. It can be unhashed without TASK_DEAD, or it can be valid with TASK_DEAD. For example, an autoreaping task can do release_task(current) long before it sets TASK_DEAD in do_exit(). Or, a zombie task can have ->state == TASK_DEAD but release_task() was not called, and in this case we must not break the loop. Change this code to check pid_alive() instead, and do this before we drop the reference to the task_struct. Note: while_each_thread() under rcu_read_lock() is not really safe, it can livelock. This will be fixed later, but fortunately in this case the "max_count" logic saves us anyway. Signed-off-by: Oleg Nesterov Acked-by: Frederic Weisbecker Acked-by: Mandeep Singh Baines Acked-by: Paul E. McKenney Cc: Tetsuo Handa Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

vfork: kill PF_STARTING

2012-03-05T23:49:42Z

Previously it was (ab)used by utrace. Then it was wrongly used by the scheduler code. Currently it is not used, kill it before it finds the new erroneous user. Signed-off-by: Oleg Nesterov Acked-by: Tejun Heo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

coredump_wait: don't call complete_vfork_done()

2012-03-05T23:49:42Z

Now that CLONE_VFORK is killable, coredump_wait() no longer needs complete_vfork_done(). zap_threads() should find and kill all tasks with the same ->mm, this includes our parent if ->vfork_done is set. mm_release() becomes the only caller, unexport complete_vfork_done(). Signed-off-by: Oleg Nesterov Acked-by: Tejun Heo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

vfork: make it killable

2012-03-05T23:49:42Z

Make vfork() killable. Change do_fork(CLONE_VFORK) to do wait_for_completion_killable(). If it fails we do not return to the user-mode and never touch the memory shared with our child. However, in this case we should clear child->vfork_done before return, we use task_lock() in do_fork()->wait_for_vfork_done() and complete_vfork_done() to serialize with each other. Note: now that we use task_lock() we don't really need completion, we could turn task->vfork_done into "task_struct *wake_up_me" but this needs some complications. NOTE: this and the next patches do not affect in-kernel users of CLONE_VFORK, kernel threads run with all signals ignored including SIGKILL/SIGSTOP. However this is obviously the user-visible change. Not only a fatal signal can kill the vforking parent, a sub-thread can do execve or exit_group() and kill the thread sleeping in vfork(). Signed-off-by: Oleg Nesterov Acked-by: Tejun Heo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

vfork: introduce complete_vfork_done()

2012-03-05T23:49:42Z

No functional changes. Move the clear-and-complete-vfork_done code into the new trivial helper, complete_vfork_done(). Signed-off-by: Oleg Nesterov Acked-by: Tejun Heo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kprobes: return proper error code from register_kprobe()

2012-03-05T23:49:42Z

register_kprobe() aborts if the address of the new request falls in a prohibited area (such as ftrace pouch, __kprobes annotated functions, non-kernel text addresses, jump label text). We however don't return the right error on this abort, resulting in a silent failure - incorrect adding/reporting of kprobes ('perf probe do_fork+18' or 'perf probe mcount' for instance). In V2 we are incorporating Masami Hiramatsu's feedback. This patch fixes it by returning -EINVAL upon failure. While we are here, rename the label used for exit to be more appropriate. Signed-off-by: Ananth N Mavinakayanahalli Signed-off-by: Prashanth K Nageshappa Acked-by: Masami Hiramatsu Cc: Jason Baron Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds