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* Merge branch 'x86-x32-for-linus' of ↵Linus Torvalds2012-03-291-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x32 support for x86-64 from Ingo Molnar: "This tree introduces the X32 binary format and execution mode for x86: 32-bit data space binaries using 64-bit instructions and 64-bit kernel syscalls. This allows applications whose working set fits into a 32 bits address space to make use of 64-bit instructions while using a 32-bit address space with shorter pointers, more compressed data structures, etc." Fix up trivial context conflicts in arch/x86/{Kconfig,vdso/vma.c} * 'x86-x32-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (71 commits) x32: Fix alignment fail in struct compat_siginfo x32: Fix stupid ia32/x32 inversion in the siginfo format x32: Add ptrace for x32 x32: Switch to a 64-bit clock_t x32: Provide separate is_ia32_task() and is_x32_task() predicates x86, mtrr: Use explicit sizing and padding for the 64-bit ioctls x86/x32: Fix the binutils auto-detect x32: Warn and disable rather than error if binutils too old x32: Only clear TIF_X32 flag once x32: Make sure TS_COMPAT is cleared for x32 tasks fs: Remove missed ->fds_bits from cessation use of fd_set structs internally fs: Fix close_on_exec pointer in alloc_fdtable x32: Drop non-__vdso weak symbols from the x32 VDSO x32: Fix coding style violations in the x32 VDSO code x32: Add x32 VDSO support x32: Allow x32 to be configured x32: If configured, add x32 system calls to system call tables x32: Handle process creation x32: Signal-related system calls x86: Add #ifdef CONFIG_COMPAT to <asm/sys_ia32.h> ...
| * Replace the fd_sets in struct fdtable with an array of unsigned longsDavid Howells2012-02-191-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Replace the fd_sets in struct fdtable with an array of unsigned longs and then use the standard non-atomic bit operations rather than the FD_* macros. This: (1) Removes the abuses of struct fd_set: (a) Since we don't want to allocate a full fd_set the vast majority of the time, we actually, in effect, just allocate a just-big-enough array of unsigned longs and cast it to an fd_set type - so why bother with the fd_set at all? (b) Some places outside of the core fdtable handling code (such as SELinux) want to look inside the array of unsigned longs hidden inside the fd_set struct for more efficient iteration over the entire set. (2) Eliminates the use of FD_*() macros in the kernel completely. (3) Permits the __FD_*() macros to be deleted entirely where not exposed to userspace. Signed-off-by: David Howells <dhowells@redhat.com> Link: http://lkml.kernel.org/r/20120216174954.23314.48147.stgit@warthog.procyon.org.uk Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Al Viro <viro@zeniv.linux.org.uk>
* | kernel/exit.c: if init dies, log a signal which killed it, if anyDenys Vlasenko2012-03-231-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I just received another user's pleas for help when their init mysteriously died. I again explained that they need to check whether it died because of bad instruction, a segv, or something else. Which was an annoying detour into writing a trivial C program to spawn his init and print its exit code: http://lists.busybox.net/pipermail/busybox/2012-January/077172.html I hear you saying "just test it under /bin/sh". Well, the crashing init _was_ /bin/sh. Which prompted me to make kernel do this first step automatically. We can print exit code, which makes it possible to see that death was from e.g. SIGILL without writing test programs. [akpm@linux-foundation.org: add 0x to hex number output] Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | prctl: add PR_{SET,GET}_CHILD_SUBREAPER to allow simple process supervisionLennart Poettering2012-03-231-5/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Userspace service managers/supervisors need to track their started services. Many services daemonize by double-forking and get implicitly re-parented to PID 1. The service manager will no longer be able to receive the SIGCHLD signals for them, and is no longer in charge of reaping the children with wait(). All information about the children is lost at the moment PID 1 cleans up the re-parented processes. With this prctl, a service manager process can mark itself as a sort of 'sub-init', able to stay as the parent for all orphaned processes created by the started services. All SIGCHLD signals will be delivered to the service manager. Receiving SIGCHLD and doing wait() is in cases of a service-manager much preferred over any possible asynchronous notification about specific PIDs, because the service manager has full access to the child process data in /proc and the PID can not be re-used until the wait(), the service-manager itself is in charge of, has happened. As a side effect, the relevant parent PID information does not get lost by a double-fork, which results in a more elaborate process tree and 'ps' output: before: # ps afx 253 ? Ss 0:00 /bin/dbus-daemon --system --nofork 294 ? Sl 0:00 /usr/libexec/polkit-1/polkitd 328 ? S 0:00 /usr/sbin/modem-manager 608 ? Sl 0:00 /usr/libexec/colord 658 ? Sl 0:00 /usr/libexec/upowerd 819 ? Sl 0:00 /usr/libexec/imsettings-daemon 916 ? Sl 0:00 /usr/libexec/udisks-daemon 917 ? S 0:00 \_ udisks-daemon: not polling any devices after: # ps afx 294 ? Ss 0:00 /bin/dbus-daemon --system --nofork 426 ? Sl 0:00 \_ /usr/libexec/polkit-1/polkitd 449 ? S 0:00 \_ /usr/sbin/modem-manager 635 ? Sl 0:00 \_ /usr/libexec/colord 705 ? Sl 0:00 \_ /usr/libexec/upowerd 959 ? Sl 0:00 \_ /usr/libexec/udisks-daemon 960 ? S 0:00 | \_ udisks-daemon: not polling any devices 977 ? Sl 0:00 \_ /usr/libexec/packagekitd This prctl is orthogonal to PID namespaces. PID namespaces are isolated from each other, while a service management process usually requires the services to live in the same namespace, to be able to talk to each other. Users of this will be the systemd per-user instance, which provides init-like functionality for the user's login session and D-Bus, which activates bus services on-demand. Both need init-like capabilities to be able to properly keep track of the services they start. Many thanks to Oleg for several rounds of review and insights. [akpm@linux-foundation.org: fix comment layout and spelling] [akpm@linux-foundation.org: add lengthy code comment from Oleg] Reviewed-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Lennart Poettering <lennart@poettering.net> Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Acked-by: Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Merge branch 'akpm' (Andrew's patch-bomb)Linus Torvalds2012-03-221-1/+1
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge first batch of patches from Andrew Morton: "A few misc things and all the MM queue" * emailed from Andrew Morton <akpm@linux-foundation.org>: (92 commits) memcg: avoid THP split in task migration thp: add HPAGE_PMD_* definitions for !CONFIG_TRANSPARENT_HUGEPAGE memcg: clean up existing move charge code mm/memcontrol.c: remove unnecessary 'break' in mem_cgroup_read() mm/memcontrol.c: remove redundant BUG_ON() in mem_cgroup_usage_unregister_event() mm/memcontrol.c: s/stealed/stolen/ memcg: fix performance of mem_cgroup_begin_update_page_stat() memcg: remove PCG_FILE_MAPPED memcg: use new logic for page stat accounting memcg: remove PCG_MOVE_LOCK flag from page_cgroup memcg: simplify move_account() check memcg: remove EXPORT_SYMBOL(mem_cgroup_update_page_stat) memcg: kill dead prev_priority stubs memcg: remove PCG_CACHE page_cgroup flag memcg: let css_get_next() rely upon rcu_read_lock() cgroup: revert ss_id_lock to spinlock idr: make idr_get_next() good for rcu_read_lock() memcg: remove unnecessary thp check in page stat accounting memcg: remove redundant returns memcg: enum lru_list lru ...
| * | mm, counters: remove task argument to sync_mm_rss() and __sync_task_rss_stat()David Rientjes2012-03-211-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | sync_mm_rss() can only be used for current to avoid race conditions in iterating and clearing its per-task counters. Remove the task argument for it and its helper function, __sync_task_rss_stat(), to avoid thinking it can be used safely for anything other than current. Signed-off-by: David Rientjes <rientjes@google.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | Merge branch 'next' of ↵Linus Torvalds2012-03-211-0/+1
|\ \ \ | |/ / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull security subsystem updates for 3.4 from James Morris: "The main addition here is the new Yama security module from Kees Cook, which was discussed at the Linux Security Summit last year. Its purpose is to collect miscellaneous DAC security enhancements in one place. This also marks a departure in policy for LSM modules, which were previously limited to being standalone access control systems. Chromium OS is using Yama, and I believe there are plans for Ubuntu, at least. This patchset also includes maintenance updates for AppArmor, TOMOYO and others." Fix trivial conflict in <net/sock.h> due to the jumo_label->static_key rename. * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (38 commits) AppArmor: Fix location of const qualifier on generated string tables TOMOYO: Return error if fails to delete a domain AppArmor: add const qualifiers to string arrays AppArmor: Add ability to load extended policy TOMOYO: Return appropriate value to poll(). AppArmor: Move path failure information into aa_get_name and rename AppArmor: Update dfa matching routines. AppArmor: Minor cleanup of d_namespace_path to consolidate error handling AppArmor: Retrieve the dentry_path for error reporting when path lookup fails AppArmor: Add const qualifiers to generated string tables AppArmor: Fix oops in policy unpack auditing AppArmor: Fix error returned when a path lookup is disconnected KEYS: testing wrong bit for KEY_FLAG_REVOKED TOMOYO: Fix mount flags checking order. security: fix ima kconfig warning AppArmor: Fix the error case for chroot relative path name lookup AppArmor: fix mapping of META_READ to audit and quiet flags AppArmor: Fix underflow in xindex calculation AppArmor: Fix dropping of allowed operations that are force audited AppArmor: Add mising end of structure test to caps unpacking ...
| * | security: trim security.hAl Viro2012-02-141-0/+1
| |/ | | | | | | | | | | | | Trim security.h Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: James Morris <jmorris@namei.org>
* | Merge tag 'pm-for-3.4' of ↵Linus Torvalds2012-03-211-1/+1
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management updates for 3.4 from Rafael Wysocki: "Assorted extensions and fixes including: * Introduction of early/late suspend/hibernation device callbacks. * Generic PM domains extensions and fixes. * devfreq updates from Axel Lin and MyungJoo Ham. * Device PM QoS updates. * Fixes of concurrency problems with wakeup sources. * System suspend and hibernation fixes." * tag 'pm-for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (43 commits) PM / Domains: Check domain status during hibernation restore of devices PM / devfreq: add relation of recommended frequency. PM / shmobile: Make MTU2 driver use pm_genpd_dev_always_on() PM / shmobile: Make CMT driver use pm_genpd_dev_always_on() PM / shmobile: Make TMU driver use pm_genpd_dev_always_on() PM / Domains: Introduce "always on" device flag PM / Domains: Fix hibernation restore of devices, v2 PM / Domains: Fix handling of wakeup devices during system resume sh_mmcif / PM: Use PM QoS latency constraint tmio_mmc / PM: Use PM QoS latency constraint PM / QoS: Make it possible to expose PM QoS latency constraints PM / Sleep: JBD and JBD2 missing set_freezable() PM / Domains: Fix include for PM_GENERIC_DOMAINS=n case PM / Freezer: Remove references to TIF_FREEZE in comments PM / Sleep: Add more wakeup source initialization routines PM / Hibernate: Enable usermodehelpers in hibernate() error path PM / Sleep: Make __pm_stay_awake() delete wakeup source timers PM / Sleep: Fix race conditions related to wakeup source timer function PM / Sleep: Fix possible infinite loop during wakeup source destruction PM / Hibernate: print physical addresses consistently with other parts of kernel ...
| * \ Merge branch 'pm-sleep'Rafael J. Wysocki2012-03-041-1/+1
| |\ \ | | |/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * pm-sleep: PM / Freezer: Remove references to TIF_FREEZE in comments PM / Sleep: Add more wakeup source initialization routines PM / Hibernate: Enable usermodehelpers in hibernate() error path PM / Sleep: Make __pm_stay_awake() delete wakeup source timers PM / Sleep: Fix race conditions related to wakeup source timer function PM / Sleep: Fix possible infinite loop during wakeup source destruction PM / Hibernate: print physical addresses consistently with other parts of kernel PM: Add comment describing relationships between PM callbacks to pm.h PM / Sleep: Drop suspend_stats_update() PM / Sleep: Make enter_state() in kernel/power/suspend.c static PM / Sleep: Unify kerneldoc comments in kernel/power/suspend.c PM / Sleep: Remove unnecessary label from suspend_freeze_processes() PM / Sleep: Do not check wakeup too often in try_to_freeze_tasks() PM / Sleep: Initialize wakeup source locks in wakeup_source_add() PM / Hibernate: Refactor and simplify freezer_test_done PM / Hibernate: Thaw kernel threads in hibernation_snapshot() in error/test path PM / Freezer / Docs: Document the beauty of freeze/thaw semantics PM / Suspend: Avoid code duplication in suspend statistics update PM / Sleep: Introduce generic callbacks for new device PM phases PM / Sleep: Introduce "late suspend" and "early resume" of devices
| | * PM / Freezer: Remove references to TIF_FREEZE in commentsMarcos Paulo de Souza2012-03-041-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch removes all the references in the code about the TIF_FREEZE flag removed by commit a3201227f803ad7fd43180c5195dbe5a2bf998aa freezer: make freezing() test freeze conditions in effect instead of TIF_FREEZE There still are some references to TIF_FREEZE in Documentation/power/freezing-of-tasks.txt, but it looks like that documentation needs more thorough work to reflect how the new freezer works, and hence merely removing the references to TIF_FREEZE won't really help. So I have not touched that part in this patch. Suggested-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Marcos Paulo de Souza <marcos.mage@gmail.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
* | | exit_signal: fix the "parent has changed security domain" logicOleg Nesterov2012-03-201-14/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | exit_notify() changes ->exit_signal if the parent already did exec. This doesn't really work, we are not going to send the signal now if there is another live thread or the exiting task is traced. The parent can exec before the last dies or the tracer detaches. Move this check into do_notify_parent() which actually sends the signal. The user-visible change is that we do not change ->exit_signal, and thus the exiting task is still "clone children" for do_wait()->eligible_child(__WCLONE). Hopefully this is fine, the current logic is racy anyway. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | exit_signal: simplify the "we have changed execution domain" logicOleg Nesterov2012-03-201-6/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | exit_notify() checks "tsk->self_exec_id != tsk->parent_exec_id" to handle the "we have changed execution domain" case. We can change do_thread() to always set ->exit_signal = SIGCHLD and remove this check to simplify the code. We could change setup_new_exec() instead, this looks more logical because it increments ->self_exec_id. But note that de_thread() already resets ->exit_signal if it changes the leader, let's keep both changes close to each other. Note that we change ->exit_signal lockless, this changes the rules. Thereafter ->exit_signal is not stable under tasklist but this is fine, the only possible change is OLDSIG -> SIGCHLD. This can race with eligible_child() but the race is harmless. We can race with reparent_leader() which changes our ->exit_signal in parallel, but it does the same change to SIGCHLD. The noticeable user-visible change is that the execing task is not "visible" to do_wait()->eligible_child(__WCLONE) right after exec. To me this looks more logical, and this is consistent with mt case. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | genirq: Get rid of unnecessary IRQTF_DIED flagAlexander Gordeev2012-03-091-2/+2
|/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently IRQTF_DIED flag is set when a IRQ thread handler calls do_exit() But also PF_EXITING per process flag gets set when a thread exits. This fix eliminates the duplicate by using PF_EXITING flag. Also, there is a race condition in exit_irq_thread(). In case a thread's bit is cleared in desc->threads_oneshot (and the IRQ line gets unmasked), but before IRQTF_DIED flag is set, a new interrupt might come in and set just cleared bit again, this time forever. This fix throws IRQTF_DIED flag away, eliminating the race as a result. [ tglx: Test THREAD_EXITING first as suggested by Oleg ] Reported-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Alexander Gordeev <agordeev@redhat.com> Link: http://lkml.kernel.org/r/20120309135958.GD2114@dhcp-26-207.brq.redhat.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* / sched: Fix ancient race in do_exit()Yasunori Goto2012-01-271-0/+16
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | try_to_wake_up() has a problem which may change status from TASK_DEAD to TASK_RUNNING in race condition with SMI or guest environment of virtual machine. As a result, exited task is scheduled() again and panic occurs. Here is the sequence how it occurs: ----------------------------------+----------------------------- | CPU A | CPU B ----------------------------------+----------------------------- TASK A calls exit().... do_exit() exit_mm() down_read(mm->mmap_sem); rwsem_down_failed_common() set TASK_UNINTERRUPTIBLE set waiter.task <= task A list_add to sem->wait_list : raw_spin_unlock_irq() (I/O interruption occured) __rwsem_do_wake(mmap_sem) list_del(&waiter->list); waiter->task = NULL wake_up_process(task A) try_to_wake_up() (task is still TASK_UNINTERRUPTIBLE) p->on_rq is still 1.) ttwu_do_wakeup() (*A) : (I/O interruption handler finished) if (!waiter.task) schedule() is not called due to waiter.task is NULL. tsk->state = TASK_RUNNING : check_preempt_curr(); : task->state = TASK_DEAD (*B) <--- set TASK_RUNNING (*C) schedule() (exit task is running again) BUG_ON() is called! -------------------------------------------------------- The execution time between (*A) and (*B) is usually very short, because the interruption is disabled, and setting TASK_RUNNING at (*C) must be executed before setting TASK_DEAD. HOWEVER, if SMI is interrupted between (*A) and (*B), (*C) is able to execute AFTER setting TASK_DEAD! Then, exited task is scheduled again, and BUG_ON() is called.... If the system works on guest system of virtual machine, the time between (*A) and (*B) may be also long due to scheduling of hypervisor, and same phenomenon can occur. By this patch, do_exit() waits for releasing task->pi_lock which is used in try_to_wake_up(). It guarantees the task becomes TASK_DEAD after waking up. Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20120117174031.3118.E1E9C6FF@jp.fujitsu.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
* Merge branch 'for-linus' of ↵Linus Torvalds2012-01-171-2/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit: (29 commits) audit: no leading space in audit_log_d_path prefix audit: treat s_id as an untrusted string audit: fix signedness bug in audit_log_execve_info() audit: comparison on interprocess fields audit: implement all object interfield comparisons audit: allow interfield comparison between gid and ogid audit: complex interfield comparison helper audit: allow interfield comparison in audit rules Kernel: Audit Support For The ARM Platform audit: do not call audit_getname on error audit: only allow tasks to set their loginuid if it is -1 audit: remove task argument to audit_set_loginuid audit: allow audit matching on inode gid audit: allow matching on obj_uid audit: remove audit_finish_fork as it can't be called audit: reject entry,always rules audit: inline audit_free to simplify the look of generic code audit: drop audit_set_macxattr as it doesn't do anything audit: inline checks for not needing to collect aux records audit: drop some potentially inadvisable likely notations ... Use evil merge to fix up grammar mistakes in Kconfig file. Bad speling and horrible grammar (and copious swearing) is to be expected, but let's keep it to commit messages and comments, rather than expose it to users in config help texts or printouts.
| * audit: inline audit_free to simplify the look of generic codeEric Paris2012-01-171-2/+1
| | | | | | | | | | | | make the conditional a static inline instead of doing it in generic code. Signed-off-by: Eric Paris <eparis@redhat.com>
* | treewide: remove useless NORET_TYPE macro and usesJoe Perches2012-01-121-3/+3
|/ | | | | | | | | | | | | | | | | | | | | | | It's a very old and now unused prototype marking so just delete it. Neaten panic pointer argument style to keep checkpatch quiet. Signed-off-by: Joe Perches <joe@perches.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Haavard Skinnemoen <hskinnemoen@gmail.com> Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'writeback-for-linus' of ↵Linus Torvalds2012-01-101-0/+3
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux * 'writeback-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux: writeback: move MIN_WRITEBACK_PAGES to fs-writeback.c writeback: balanced_rate cannot exceed write bandwidth writeback: do strict bdi dirty_exceeded writeback: avoid tiny dirty poll intervals writeback: max, min and target dirty pause time writeback: dirty ratelimit - think time compensation btrfs: fix dirtied pages accounting on sub-page writes writeback: fix dirtied pages accounting on redirty writeback: fix dirtied pages accounting on sub-page writes writeback: charge leaked page dirties to active tasks writeback: Include all dirty inodes in background writeback
| * writeback: charge leaked page dirties to active tasksWu Fengguang2011-12-181-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It's a years long problem that a large number of short-lived dirtiers (eg. gcc instances in a fast kernel build) may starve long-run dirtiers (eg. dd) as well as pushing the dirty pages to the global hard limit. The solution is to charge the pages dirtied by the exited gcc to the other random dirtying tasks. It sounds not perfect, however should behave good enough in practice, seeing as that throttled tasks aren't actually running so those that are running are more likely to pick it up and get throttled, therefore promoting an equal spread. Randy: fix compile error: 'dirty_throttle_leaks' undeclared in exit.c Acked-by: Jan Kara <jack@suse.cz> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
* | Merge branch 'pm-for-linus' of ↵Linus Torvalds2012-01-081-2/+1
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm * 'pm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (76 commits) PM / Hibernate: Implement compat_ioctl for /dev/snapshot PM / Freezer: fix return value of freezable_schedule_timeout_killable() PM / shmobile: Allow the A4R domain to be turned off at run time PM / input / touchscreen: Make st1232 use device PM QoS constraints PM / QoS: Introduce dev_pm_qos_add_ancestor_request() PM / shmobile: Remove the stay_on flag from SH7372's PM domains PM / shmobile: Don't include SH7372's INTCS in syscore suspend/resume PM / shmobile: Add support for the sh7372 A4S power domain / sleep mode PM: Drop generic_subsys_pm_ops PM / Sleep: Remove forward-only callbacks from AMBA bus type PM / Sleep: Remove forward-only callbacks from platform bus type PM: Run the driver callback directly if the subsystem one is not there PM / Sleep: Make pm_op() and pm_noirq_op() return callback pointers PM/Devfreq: Add Exynos4-bus device DVFS driver for Exynos4210/4212/4412. PM / Sleep: Merge internal functions in generic_ops.c PM / Sleep: Simplify generic system suspend callbacks PM / Hibernate: Remove deprecated hibernation snapshot ioctls PM / Sleep: Fix freezer failures due to racy usermodehelper_is_disabled() ARM: S3C64XX: Implement basic power domain support PM / shmobile: Use common always on power domain governor ... Fix up trivial conflict in fs/xfs/xfs_buf.c due to removal of unused XBT_FORCE_SLEEP bit
| * | freezer: remove racy clear_freeze_flag() and set PF_NOFREEZE on dead tasksTejun Heo2011-11-211-2/+1
| |/ | | | | | | | | | | | | | | | | | | | | | | | | clear_freeze_flag() in exit_mm() is racy. Freezing can start afterwards. Remove it. Skipping freezer for exiting task will be properly implemented later. Also, freezable() was testing exit_state directly to make system freezer ignore dead tasks. Let the exiting task set PF_NOFREEZE after entering TASK_DEAD instead. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com>
* | Merge branch 'sched-core-for-linus' of ↵Linus Torvalds2012-01-061-16/+6
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits) sched/tracing: Add a new tracepoint for sleeptime sched: Disable scheduler warnings during oopses sched: Fix cgroup movement of waking process sched: Fix cgroup movement of newly created process sched: Fix cgroup movement of forking process sched: Remove cfs bandwidth period check in tg_set_cfs_period() sched: Fix load-balance lock-breaking sched: Replace all_pinned with a generic flags field sched: Only queue remote wakeups when crossing cache boundaries sched: Add missing rcu_dereference() around ->real_parent usage [S390] fix cputime overflow in uptime_proc_show [S390] cputime: add sparse checking and cleanup sched: Mark parent and real_parent as __rcu sched, nohz: Fix missing RCU read lock sched, nohz: Set the NOHZ_BALANCE_KICK flag for idle load balancer sched, nohz: Fix the idle cpu check in nohz_idle_balance sched: Use jump_labels for sched_feat sched/accounting: Fix parameter passing in task_group_account_field sched/accounting: Fix user/system tick double accounting sched/accounting: Re-use scheduler statistics for the root cgroup ... Fix up conflicts in - arch/ia64/include/asm/cputime.h, include/asm-generic/cputime.h usecs_to_cputime64() vs the sparse cleanups - kernel/sched/fair.c, kernel/time/tick-sched.c scheduler changes in multiple branches
| * | [S390] cputime: add sparse checking and cleanupMartin Schwidefsky2011-12-151-16/+6
| |/ | | | | | | | | | | | | | | Make cputime_t and cputime64_t nocast to enable sparse checking to detect incorrect use of cputime. Drop the cputime macros for simple scalar operations. The conversion macros are still needed. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* / ptrace: partially fix the do_wait(WEXITED) vs EXIT_DEAD->EXIT_ZOMBIE raceOleg Nesterov2012-01-041-1/+8
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Test-case: int main(void) { int pid, status; pid = fork(); if (!pid) { for (;;) { if (!fork()) return 0; if (waitpid(-1, &status, 0) < 0) { printf("ERR!! wait: %m\n"); return 0; } } } assert(ptrace(PTRACE_ATTACH, pid, 0,0) == 0); assert(waitpid(-1, NULL, 0) == pid); assert(ptrace(PTRACE_SETOPTIONS, pid, 0, PTRACE_O_TRACEFORK) == 0); do { ptrace(PTRACE_CONT, pid, 0, 0); pid = waitpid(-1, NULL, 0); } while (pid > 0); return 1; } It fails because ->real_parent sees its child in EXIT_DEAD state while the tracer is going to change the state back to EXIT_ZOMBIE in wait_task_zombie(). The offending commit is 823b018e which moved the EXIT_DEAD check, but in fact we should not blame it. The original code was not correct as well because it didn't take ptrace_reparented() into account and because we can't really trust ->ptrace. This patch adds the additional check to close this particular race but it doesn't solve the whole problem. We simply can't rely on ->ptrace in this case, it can be cleared if the tracer is multithreaded by the exiting ->parent. I think we should kill EXIT_DEAD altogether, we should always remove the soon-to-be-reaped child from ->children or at least we should never do the DEAD->ZOMBIE transition. But this is too complex for 3.2. Reported-and-tested-by: Denys Vlasenko <vda.linux@googlemail.com> Tested-by: Lukasz Michalik <lmi@ift.uni.wroc.pl> Acked-by: Tejun Heo <tj@kernel.org> Cc: <stable@kernel.org> [3.0+] Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* oom: remove oom_disable_countDavid Rientjes2011-10-311-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | This removes mm->oom_disable_count entirely since it's unnecessary and currently buggy. The counter was intended to be per-process but it's currently decremented in the exit path for each thread that exits, causing it to underflow. The count was originally intended to prevent oom killing threads that share memory with threads that cannot be killed since it doesn't lead to future memory freeing. The counter could be fixed to represent all threads sharing the same mm, but it's better to remove the count since: - it is possible that the OOM_DISABLE thread sharing memory with the victim is waiting on that thread to exit and will actually cause future memory freeing, and - there is no guarantee that a thread is disabled from oom killing just because another thread sharing its mm is oom disabled. Signed-off-by: David Rientjes <rientjes@google.com> Reported-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Cc: Ying Han <yinghan@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc: introduce shm_rmid_forced sysctlVasiliy Kulikov2011-07-261-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add support for the shm_rmid_forced sysctl. If set to 1, all shared memory objects in current ipc namespace will be automatically forced to use IPC_RMID. The POSIX way of handling shmem allows one to create shm objects and call shmdt(), leaving shm object associated with no process, thus consuming memory not counted via rlimits. With shm_rmid_forced=1 the shared memory object is counted at least for one process, so OOM killer may effectively kill the fat process holding the shared memory. It obviously breaks POSIX - some programs relying on the feature would stop working. So set shm_rmid_forced=1 only if you're sure nobody uses "orphaned" memory. Use shm_rmid_forced=0 by default for compatability reasons. The feature was previously impemented in -ow as a configure option. [akpm@linux-foundation.org: fix documentation, per Randy] [akpm@linux-foundation.org: fix warning] [akpm@linux-foundation.org: readability/conventionality tweaks] [akpm@linux-foundation.org: fix shm_rmid_forced/shm_forced_rmid confusion, use standard comment layout] Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Cc: Randy Dunlap <rdunlap@xenotime.net> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: "Serge E. Hallyn" <serge.hallyn@canonical.com> Cc: Daniel Lezcano <daniel.lezcano@free.fr> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Tejun Heo <tj@kernel.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Solar Designer <solar@openwall.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'for-linus' of ↵Linus Torvalds2011-07-251-1/+0
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (43 commits) fs: Merge split strings treewide: fix potentially dangerous trailing ';' in #defined values/expressions uwb: Fix misspelling of neighbourhood in comment net, netfilter: Remove redundant goto in ebt_ulog_packet trivial: don't touch files that are removed in the staging tree lib/vsprintf: replace link to Draft by final RFC number doc: Kconfig: `to be' -> `be' doc: Kconfig: Typo: square -> squared doc: Konfig: Documentation/power/{pm => apm-acpi}.txt drivers/net: static should be at beginning of declaration drivers/media: static should be at beginning of declaration drivers/i2c: static should be at beginning of declaration XTENSA: static should be at beginning of declaration SH: static should be at beginning of declaration MIPS: static should be at beginning of declaration ARM: static should be at beginning of declaration rcu: treewide: Do not use rcu_read_lock_held when calling rcu_dereference_check Update my e-mail address PCIe ASPM: forcedly -> forcibly gma500: push through device driver tree ... Fix up trivial conflicts: - arch/arm/mach-ep93xx/dma-m2p.c (deleted) - drivers/gpio/gpio-ep93xx.c (renamed and context nearby) - drivers/net/r8169.c (just context changes)
| * Merge branch 'master' into for-nextJiri Kosina2011-07-111-16/+15
| |\ | | | | | | | | | | | | Sync with Linus' tree to be able to apply pending patches that are based on newer code already present upstream.
| * | rcu: treewide: Do not use rcu_read_lock_held when calling rcu_dereference_checkMichal Hocko2011-07-081-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since ca5ecddf (rcu: define __rcu address space modifier for sparse) rcu_dereference_check use rcu_read_lock_held as a part of condition automatically so callers do not have to do that as well. Signed-off-by: Michal Hocko <mhocko@suse.cz> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* | | Merge branch 'for-3.1/core' of git://git.kernel.dk/linux-blockLinus Torvalds2011-07-251-1/+0
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'for-3.1/core' of git://git.kernel.dk/linux-block: (24 commits) block: strict rq_affinity backing-dev: use synchronize_rcu_expedited instead of synchronize_rcu block: fix patch import error in max_discard_sectors check block: reorder request_queue to remove 64 bit alignment padding CFQ: add think time check for group CFQ: add think time check for service tree CFQ: move think time check variables to a separate struct fixlet: Remove fs_excl from struct task. cfq: Remove special treatment for metadata rqs. block: document blk_plug list access block: avoid building too big plug list compat_ioctl: fix make headers_check regression block: eliminate potential for infinite loop in blkdev_issue_discard compat_ioctl: fix warning caused by qemu block: flush MEDIA_CHANGE from drivers on close(2) blk-throttle: Make total_nr_queued unsigned block: Add __attribute__((format(printf...) and fix fallout fs/partitions/check.c: make local symbols static block:remove some spare spaces in genhd.c block:fix the comment error in blkdev.h ...
| * | | fixlet: Remove fs_excl from struct task.Justin TerAvest2011-07-121-1/+0
| | |/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | fs_excl is a poor man's priority inheritance for filesystems to hint to the block layer that an operation is important. It was never clearly specified, not widely adopted, and will not prevent starvation in many cases (like across cgroups). fs_excl was introduced with the time sliced CFQ IO scheduler, to indicate when a process held FS exclusive resources and thus needed a boost. It doesn't cover all file systems, and it was never fully complete. Lets kill it. Signed-off-by: Justin TerAvest <teravest@google.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
* | | Merge branch 'ptrace' of git://git.kernel.org/pub/scm/linux/kernel/git/oleg/miscLinus Torvalds2011-07-221-51/+40
|\ \ \ | |/ / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'ptrace' of git://git.kernel.org/pub/scm/linux/kernel/git/oleg/misc: (39 commits) ptrace: do_wait(traced_leader_killed_by_mt_exec) can block forever ptrace: fix ptrace_signal() && STOP_DEQUEUED interaction connector: add an event for monitoring process tracers ptrace: dont send SIGSTOP on auto-attach if PT_SEIZED ptrace: mv send-SIGSTOP from do_fork() to ptrace_init_task() ptrace_init_task: initialize child->jobctl explicitly has_stopped_jobs: s/task_is_stopped/SIGNAL_STOP_STOPPED/ ptrace: make former thread ID available via PTRACE_GETEVENTMSG after PTRACE_EVENT_EXEC stop ptrace: wait_consider_task: s/same_thread_group/ptrace_reparented/ ptrace: kill real_parent_is_ptracer() in in favor of ptrace_reparented() ptrace: ptrace_reparented() should check same_thread_group() redefine thread_group_leader() as exit_signal >= 0 do not change dead_task->exit_signal kill task_detached() reparent_leader: check EXIT_DEAD instead of task_detached() make do_notify_parent() __must_check, update the callers __ptrace_detach: avoid task_detached(), check do_notify_parent() kill tracehook_notify_death() make do_notify_parent() return bool ptrace: s/tracehook_tracer_task()/ptrace_parent()/ ...
| * | has_stopped_jobs: s/task_is_stopped/SIGNAL_STOP_STOPPED/Oleg Nesterov2011-07-171-7/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | has_stopped_jobs() naively checks task_is_stopped(group_leader). This was always wrong even without ptrace, group_leader can be dead. And given that ptrace can change the state to TRACED this is wrong even in the single-threaded case. Change the code to check SIGNAL_STOP_STOPPED and simplify the code, retval + break/continue doesn't make this trivial code more readable. We could probably add the usual "|| signal->group_stop_count" check but I don't think this makes sense, the task can start the group-stop right after the check anyway. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Tejun Heo <tj@kernel.org>
| * | ptrace: wait_consider_task: s/same_thread_group/ptrace_reparented/Oleg Nesterov2011-06-271-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | wait_consider_task() checks same_thread_group(parent, real_parent), this is the open-coded ptrace_reparented(). __ptrace_detach() remains the only function which has to check this by hand, although we could reorganize the code to delay __ptrace_unlink. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Tejun Heo <tj@kernel.org>
| * | kill task_detached()Oleg Nesterov2011-06-271-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | Upadate the last user of task_detached(), wait_task_zombie(), to use thread_group_leader() and kill task_detached(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Tejun Heo <tj@kernel.org>
| * | reparent_leader: check EXIT_DEAD instead of task_detached()Oleg Nesterov2011-06-271-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change reparent_leader() to check ->exit_state instead of ->exit_signal, this matches the similar EXIT_DEAD check in wait_consider_task() and allows us to cleanup the do_notify_parent/task_detached logic. task_detached() was really needed during reparenting before 9cd80bbb "do_wait() optimization: do not place sub-threads on ->children list" to filter out the sub-threads. After this change task_detached(p) can only be true if p is the dead group_leader and its parent ignores SIGCHLD, in this case the caller of do_notify_parent() is going to reap this task and it should set EXIT_DEAD. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Tejun Heo <tj@kernel.org>
| * | make do_notify_parent() __must_check, update the callersOleg Nesterov2011-06-271-21/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change other callers of do_notify_parent() to check the value it returns, this makes the subsequent task_detached() unnecessary. Mark do_notify_parent() as __must_check. Use thread_group_leader() instead of !task_detached() to check if we need to notify the real parent in wait_task_zombie(). Remove the stale comment in release_task(). "just for sanity" is no longer true, we have to set EXIT_DEAD to avoid the races with do_wait(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Tejun Heo <tj@kernel.org>
| * | kill tracehook_notify_death()Oleg Nesterov2011-06-271-8/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Kill tracehook_notify_death(), reimplement the logic in its caller, exit_notify(). Also, change the exec_id's check to use thread_group_leader() instead of task_detached(), this is more clear. This logic only applies to the exiting leader, a sub-thread must never change its exit_signal. Note: when the traced group leader exits the exit_signal-or-SIGCHLD logic looks really strange: - we notify the tracer even if !thread_group_empty() but do_wait(WEXITED) can't work until all threads exit - if the tracer is real_parent, it is not clear why can't we use ->exit_signal event if !thread_group_empty() -v2: do not try to fix the 2nd oddity to avoid the subtle behavior change mixed with reorganization, suggested by Tejun. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Tejun Heo <tj@kernel.org>
| * | make do_notify_parent() return boolOleg Nesterov2011-06-271-3/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - change do_notify_parent() to return a boolean, true if the task should be reaped because its parent ignores SIGCHLD. - update the only caller which checks the returned value, exit_notify(). This temporary uglifies exit_notify() even more, will be cleanuped by the next change. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Tejun Heo <tj@kernel.org>
| * | ptrace: kill trivial tracehooksTejun Heo2011-06-221-5/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | At this point, tracehooks aren't useful to mainline kernel and mostly just add an extra layer of obfuscation. Although they have comments, without actual in-kernel users, it is difficult to tell what are their assumptions and they're actually trying to achieve. To mainline kernel, they just aren't worth keeping around. This patch kills the following trivial tracehooks. * Ones testing whether task is ptraced. Replace with ->ptrace test. tracehook_expect_breakpoints() tracehook_consider_ignored_signal() tracehook_consider_fatal_signal() * ptrace_event() wrappers. Call directly. tracehook_report_exec() tracehook_report_exit() tracehook_report_vfork_done() * ptrace_release_task() wrapper. Call directly. tracehook_finish_release_task() * noop tracehook_prepare_release_task() tracehook_report_death() This doesn't introduce any behavior change. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com>
| * | ptrace: kill task_ptrace()Tejun Heo2011-06-221-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | task_ptrace(task) simply dereferences task->ptrace and isn't even used consistently only adding confusion. Kill it and directly access ->ptrace instead. This doesn't introduce any behavior change. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Oleg Nesterov <oleg@redhat.com>
| * | ptrace: implement PTRACE_LISTENTejun Heo2011-06-161-1/+2
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The previous patch implemented async notification for ptrace but it only worked while trace is running. This patch introduces PTRACE_LISTEN which is suggested by Oleg Nestrov. It's allowed iff tracee is in STOP trap and puts tracee into quasi-running state - tracee never really runs but wait(2) and ptrace(2) consider it to be running. While ptracer is listening, tracee is allowed to re-enter STOP to notify an async event. Listening state is cleared on the first notification. Ptracer can also clear it by issuing INTERRUPT - tracee will re-trap into STOP with listening state cleared. This allows ptracer to monitor group stop state without running tracee - use INTERRUPT to put tracee into STOP trap, issue LISTEN and then wait(2) to wait for the next group stop event. When it happens, PTRACE_GETSIGINFO provides information to determine the current state. Test program follows. #define PTRACE_SEIZE 0x4206 #define PTRACE_INTERRUPT 0x4207 #define PTRACE_LISTEN 0x4208 #define PTRACE_SEIZE_DEVEL 0x80000000 static const struct timespec ts1s = { .tv_sec = 1 }; int main(int argc, char **argv) { pid_t tracee, tracer; int i; tracee = fork(); if (!tracee) while (1) pause(); tracer = fork(); if (!tracer) { siginfo_t si; ptrace(PTRACE_SEIZE, tracee, NULL, (void *)(unsigned long)PTRACE_SEIZE_DEVEL); ptrace(PTRACE_INTERRUPT, tracee, NULL, NULL); repeat: waitid(P_PID, tracee, NULL, WSTOPPED); ptrace(PTRACE_GETSIGINFO, tracee, NULL, &si); if (!si.si_code) { printf("tracer: SIG %d\n", si.si_signo); ptrace(PTRACE_CONT, tracee, NULL, (void *)(unsigned long)si.si_signo); goto repeat; } printf("tracer: stopped=%d signo=%d\n", si.si_signo != SIGTRAP, si.si_signo); if (si.si_signo != SIGTRAP) ptrace(PTRACE_LISTEN, tracee, NULL, NULL); else ptrace(PTRACE_CONT, tracee, NULL, NULL); goto repeat; } for (i = 0; i < 3; i++) { nanosleep(&ts1s, NULL); printf("mother: SIGSTOP\n"); kill(tracee, SIGSTOP); nanosleep(&ts1s, NULL); printf("mother: SIGCONT\n"); kill(tracee, SIGCONT); } nanosleep(&ts1s, NULL); kill(tracer, SIGKILL); kill(tracee, SIGKILL); return 0; } This is identical to the program to test TRAP_NOTIFY except that tracee is PTRACE_LISTEN'd instead of PTRACE_CONT'd when group stopped. This allows ptracer to monitor when group stop ends without running tracee. # ./test-listen tracer: stopped=0 signo=5 mother: SIGSTOP tracer: SIG 19 tracer: stopped=1 signo=19 mother: SIGCONT tracer: stopped=0 signo=5 tracer: SIG 18 mother: SIGSTOP tracer: SIG 19 tracer: stopped=1 signo=19 mother: SIGCONT tracer: stopped=0 signo=5 tracer: SIG 18 mother: SIGSTOP tracer: SIG 19 tracer: stopped=1 signo=19 mother: SIGCONT tracer: stopped=0 signo=5 tracer: SIG 18 -v2: Moved JOBCTL_LISTENING check in wait_task_stopped() into task_stopped_code() as suggested by Oleg. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com>
* / memcg: clear mm->owner when last possible owner leavesKAMEZAWA Hiroyuki2011-06-151-16/+15
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The following crash was reported: > Call Trace: > [<ffffffff81139792>] mem_cgroup_from_task+0x15/0x17 > [<ffffffff8113a75a>] __mem_cgroup_try_charge+0x148/0x4b4 > [<ffffffff810493f3>] ? need_resched+0x23/0x2d > [<ffffffff814cbf43>] ? preempt_schedule+0x46/0x4f > [<ffffffff8113afe8>] mem_cgroup_charge_common+0x9a/0xce > [<ffffffff8113b6d1>] mem_cgroup_newpage_charge+0x5d/0x5f > [<ffffffff81134024>] khugepaged+0x5da/0xfaf > [<ffffffff81078ea0>] ? __init_waitqueue_head+0x4b/0x4b > [<ffffffff81133a4a>] ? add_mm_counter.constprop.5+0x13/0x13 > [<ffffffff81078625>] kthread+0xa8/0xb0 > [<ffffffff814d13e8>] ? sub_preempt_count+0xa1/0xb4 > [<ffffffff814d5664>] kernel_thread_helper+0x4/0x10 > [<ffffffff814ce858>] ? retint_restore_args+0x13/0x13 > [<ffffffff8107857d>] ? __init_kthread_worker+0x5a/0x5a What happens is that khugepaged tries to charge a huge page against an mm whose last possible owner has already exited, and the memory controller crashes when the stale mm->owner is used to look up the cgroup to charge. mm->owner has never been set to NULL with the last owner going away, but nobody cared until khugepaged came along. Even then it wasn't a problem because the final mmput() on an mm was forced to acquire and release mmap_sem in write-mode, preventing an exiting owner to go away while the mmap_sem was held, and until "692e0b3 mm: thp: optimize memcg charge in khugepaged", the memory cgroup charge was protected by mmap_sem in read-mode. Instead of going back to relying on the mmap_sem to enforce lifetime of a task, this patch ensures that mm->owner is properly set to NULL when the last possible owner is exiting, which the memory controller can handle just fine. [akpm@linux-foundation.org: tweak comments] Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reported-by: Hugh Dickins <hughd@google.com> Reported-by: Dave Jones <davej@redhat.com> Reviewed-by: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'ptrace' of git://git.kernel.org/pub/scm/linux/kernel/git/oleg/miscLinus Torvalds2011-05-201-22/+88
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'ptrace' of git://git.kernel.org/pub/scm/linux/kernel/git/oleg/misc: (41 commits) signal: trivial, fix the "timespec declared inside parameter list" warning job control: reorganize wait_task_stopped() ptrace: fix signal->wait_chldexit usage in task_clear_group_stop_trapping() signal: sys_sigprocmask() needs retarget_shared_pending() signal: cleanup sys_sigprocmask() signal: rename signandsets() to sigandnsets() signal: do_sigtimedwait() needs retarget_shared_pending() signal: introduce do_sigtimedwait() to factor out compat/native code signal: sys_rt_sigtimedwait: simplify the timeout logic signal: cleanup sys_rt_sigprocmask() x86: signal: sys_rt_sigreturn() should use set_current_blocked() x86: signal: handle_signal() should use set_current_blocked() signal: sigprocmask() should do retarget_shared_pending() signal: sigprocmask: narrow the scope of ->siglock signal: retarget_shared_pending: optimize while_each_thread() loop signal: retarget_shared_pending: consider shared/unblocked signals only signal: introduce retarget_shared_pending() ptrace: ptrace_check_attach() should not do s/STOPPED/TRACED/ signal: Turn SIGNAL_STOP_DEQUEUED into GROUP_STOP_DEQUEUED signal: do_signal_stop: Remove the unneeded task_clear_group_stop_pending() ...
| * job control: reorganize wait_task_stopped()Tejun Heo2011-05-131-7/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | wait_task_stopped() tested task_stopped_code() without acquiring siglock and, if stop condition existed, called wait_task_stopped() and directly returned the result. This patch moves the initial task_stopped_code() testing into wait_task_stopped() and make wait_consider_task() fall through to wait_task_continue() on 0 return. This is for the following two reasons. * Because the initial task_stopped_code() test is done without acquiring siglock, it may race against SIGCONT generation. The stopped condition might have been replaced by continued state by the time wait_task_stopped() acquired siglock. This may lead to unexpected failure of WNOHANG waits. This reorganization addresses this single race case but there are other cases - TASK_RUNNING -> TASK_STOPPED transition and EXIT_* transitions. * Scheduled ptrace updates require changes to the initial test which would fit better inside wait_task_stopped(). Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com>
| * Merge branch 'ptrace' of ↵Oleg Nesterov2011-04-071-17/+67
| |\ | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc into ptrace
| | * job control: Allow access to job control events through ptraceesTejun Heo2011-03-231-8/+33
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently a real parent can't access job control stopped/continued events through a ptraced child. This utterly breaks job control when the children are ptraced. For example, if a program is run from an interactive shell and then strace(1) attaches to it, pressing ^Z would send SIGTSTP and strace(1) would notice it but the shell has no way to tell whether the child entered job control stop and thus can't tell when to take over the terminal - leading to awkward lone ^Z on the terminal. Because the job control and ptrace stopped states are independent, there is no reason to prevent real parents from accessing the stopped state regardless of ptrace. The continued state isn't separate but ptracers don't have any use for them as ptracees can never resume without explicit command from their ptracers, so as long as ptracers don't consume it, it should be fine. Although this is a behavior change, because the previous behavior is utterly broken when viewed from real parents and the change is only visible to real parents, I don't think it's necessary to make this behavior optional. One situation to be careful about is when a task from the real parent's group is ptracing. The parent group is the recipient of both ptrace and job control stop events and one stop can be reported as both job control and ptrace stops. As this can break the current ptrace users, suppress job control stopped events for these cases. If a real parent ptracer wants to know about both job control and ptrace stops, it can create a separate process to serve the role of real parent. Note that this only updates wait(2) side of things. The real parent can access the states via wait(2) but still is not properly notified (woken up and delivered signal). Test case polls wait(2) with WNOHANG to work around. Notification will be updated by future patches. Test case follows. #include <stdio.h> #include <unistd.h> #include <time.h> #include <errno.h> #include <sys/types.h> #include <sys/ptrace.h> #include <sys/wait.h> int main(void) { const struct timespec ts100ms = { .tv_nsec = 100000000 }; pid_t tracee, tracer; siginfo_t si; int i; tracee = fork(); if (tracee == 0) { while (1) { printf("tracee: SIGSTOP\n"); raise(SIGSTOP); nanosleep(&ts100ms, NULL); printf("tracee: SIGCONT\n"); raise(SIGCONT); nanosleep(&ts100ms, NULL); } } waitid(P_PID, tracee, &si, WSTOPPED | WNOHANG | WNOWAIT); tracer = fork(); if (tracer == 0) { nanosleep(&ts100ms, NULL); ptrace(PTRACE_ATTACH, tracee, NULL, NULL); for (i = 0; i < 11; i++) { si.si_pid = 0; waitid(P_PID, tracee, &si, WSTOPPED); if (si.si_pid && si.si_code == CLD_TRAPPED) ptrace(PTRACE_CONT, tracee, NULL, (void *)(long)si.si_status); } printf("tracer: EXITING\n"); return 0; } while (1) { si.si_pid = 0; waitid(P_PID, tracee, &si, WSTOPPED | WCONTINUED | WEXITED | WNOHANG); if (si.si_pid) printf("mommy : WAIT status=%02d code=%02d\n", si.si_status, si.si_code); nanosleep(&ts100ms, NULL); } return 0; } Before the patch, while ptraced, the parent can't see any job control events. tracee: SIGSTOP mommy : WAIT status=19 code=05 tracee: SIGCONT tracee: SIGSTOP tracee: SIGCONT tracee: SIGSTOP tracee: SIGCONT tracee: SIGSTOP tracer: EXITING mommy : WAIT status=19 code=05 ^C After the patch, tracee: SIGSTOP mommy : WAIT status=19 code=05 tracee: SIGCONT mommy : WAIT status=18 code=06 tracee: SIGSTOP mommy : WAIT status=19 code=05 tracee: SIGCONT mommy : WAIT status=18 code=06 tracee: SIGSTOP mommy : WAIT status=19 code=05 tracee: SIGCONT mommy : WAIT status=18 code=06 tracee: SIGSTOP tracer: EXITING mommy : WAIT status=19 code=05 ^C -v2: Oleg pointed out that wait(2) should be suppressed for the real parent's group instead of only the real parent task itself. Updated accordingly. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Oleg Nesterov <oleg@redhat.com>
| | * job control: Fix ptracer wait(2) hang and explain notask_error clearingTejun Heo2011-03-231-10/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | wait(2) and friends allow access to stopped/continued states through zombies, which is required as the states are process-wide and should be accessible whether the leader task is alive or undead. wait_consider_task() implements this by always clearing notask_error and going through wait_task_stopped/continued() for unreaped zombies. However, while ptraced, the stopped state is per-task and as such if the ptracee became a zombie, there's no further stopped event to listen to and wait(2) and friends should return -ECHILD on the tracee. Fix it by clearing notask_error only if WCONTINUED | WEXITED is set for ptraced zombies. While at it, document why clearing notask_error is safe for each case. Test case follows. #include <stdio.h> #include <unistd.h> #include <pthread.h> #include <time.h> #include <sys/types.h> #include <sys/ptrace.h> #include <sys/wait.h> static void *nooper(void *arg) { pause(); return NULL; } int main(void) { const struct timespec ts1s = { .tv_sec = 1 }; pid_t tracee, tracer; siginfo_t si; tracee = fork(); if (tracee == 0) { pthread_t thr; pthread_create(&thr, NULL, nooper, NULL); nanosleep(&ts1s, NULL); printf("tracee exiting\n"); pthread_exit(NULL); /* let subthread run */ } tracer = fork(); if (tracer == 0) { ptrace(PTRACE_ATTACH, tracee, NULL, NULL); while (1) { if (waitid(P_PID, tracee, &si, WSTOPPED) < 0) { perror("waitid"); break; } ptrace(PTRACE_CONT, tracee, NULL, (void *)(long)si.si_status); } return 0; } waitid(P_PID, tracer, &si, WEXITED); kill(tracee, SIGKILL); return 0; } Before the patch, after the tracee becomes a zombie, the tracer's waitid(WSTOPPED) never returns and the program doesn't terminate. tracee exiting ^C After the patch, tracee exiting triggers waitid() to fail. tracee exiting waitid: No child processes -v2: Oleg pointed out that exited in addition to continued can happen for ptraced dead group leader. Clear notask_error for ptraced child on WEXITED too. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Oleg Nesterov <oleg@redhat.com>
| | * job control: Small reorganization of wait_consider_task()Tejun Heo2011-03-231-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | Move EXIT_DEAD test in wait_consider_task() above ptrace check. As ptraced tasks can't be EXIT_DEAD, this change doesn't cause any behavior change. This is to prepare for further changes. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Oleg Nesterov <oleg@redhat.com>