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* Audit: Final renamings and cleanupAhmed S. Darwish2008-04-18
| | | | | | | | | Rename the se_str and se_rule audit fields elements to lsm_str and lsm_rule to avoid confusion. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com> Acked-by: James Morris <jmorris@namei.org>
* SELinux: use new audit hooks, remove redundant exportsAhmed S. Darwish2008-04-18
| | | | | | | | | | | | | Setup the new Audit LSM hooks for SELinux. Remove the now redundant exported SELinux Audit interface. Audit: Export 'audit_krule' and 'audit_field' to the public since their internals are needed by the implementation of the new LSM hook 'audit_rule_known'. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com> Acked-by: James Morris <jmorris@namei.org>
* Audit: internally use the new LSM audit hooksAhmed S. Darwish2008-04-18
| | | | | | | | | | | | | | | | | | | | | Convert Audit to use the new LSM Audit hooks instead of the exported SELinux interface. Basically, use: security_audit_rule_init secuirty_audit_rule_free security_audit_rule_known security_audit_rule_match instad of (respectively) : selinux_audit_rule_init selinux_audit_rule_free audit_rule_has_selinux selinux_audit_rule_match Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com> Acked-by: James Morris <jmorris@namei.org>
* Audit: use new LSM hooks instead of SELinux exportsAhmed S. Darwish2008-04-18
| | | | | | | | | | | | | | | | | | | | | | | | Stop using the following exported SELinux interfaces: selinux_get_inode_sid(inode, sid) selinux_get_ipc_sid(ipcp, sid) selinux_get_task_sid(tsk, sid) selinux_sid_to_string(sid, ctx, len) kfree(ctx) and use following generic LSM equivalents respectively: security_inode_getsecid(inode, secid) security_ipc_getsecid*(ipcp, secid) security_task_getsecid(tsk, secid) security_sid_to_secctx(sid, ctx, len) security_release_secctx(ctx, len) Call security_release_secctx only if security_secid_to_secctx succeeded. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com> Acked-by: James Morris <jmorris@namei.org> Reviewed-by: Paul Moore <paul.moore@hp.com>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/tglx/linux-2.6-hrtLinus Torvalds2008-04-18
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | * git://git.kernel.org/pub/scm/linux/kernel/git/tglx/linux-2.6-hrt: clocksource: make clocksource watchdog cycle through online CPUs Documentation: move timer related documentation to a single place clockevents: optimise tick_nohz_stop_sched_tick() a bit locking: remove unused double_spin_lock() hrtimers: simplify lockdep handling timers: simplify lockdep handling posix-timers: fix shadowed variables timer_list: add annotations to workqueue.c hrtimer: use nanosleep specific restart_block fields hrtimer: add nanosleep specific restart_block member
| * clocksource: make clocksource watchdog cycle through online CPUsAndi Kleen2008-04-17
| | | | | | | | | | | | | | | | | | | | This way it checks if the clocks are synchronized between CPUs too. This might be able to detect slowly drifting TSCs which only go wrong over longer time. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * clockevents: optimise tick_nohz_stop_sched_tick() a bitKarsten Wiese2008-04-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Call ts = &per_cpu(tick_cpu_sched, cpu); and cpu = smp_processor_id(); once instead of twice. No functional change done, as changed code runs with local irq off. Reduces source lines and text size (20bytes on x86_64). [ akpm@linux-foundation.org: Build fix ] Signed-off-by: Karsten Wiese <fzu@wemgehoertderstaat.de> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * hrtimers: simplify lockdep handlingOleg Nesterov2008-04-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In order to avoid the false positive from lockdep, each per-cpu base->lock has the separate lock class and migrate_hrtimers() uses double_spin_lock(). This is overcomplicated: except for migrate_hrtimers() we never take 2 locks at once, and migrate_hrtimers() can use spin_lock_nested(). Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * timers: simplify lockdep handlingOleg Nesterov2008-04-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In order to avoid the false positive from lockdep, each per-cpu base->lock has the separate lock class and migrate_timers() uses double_spin_lock(). This all is overcomplicated: except for migrate_timers() we never take 2 locks at once, and migrate_timers() can use spin_lock_nested(). Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * posix-timers: fix shadowed variablesWANG Cong2008-04-17
| | | | | | | | | | | | | | | | | | | | Fix sparse warnings like this: kernel/posix-cpu-timers.c:1090:25: warning: symbol 't' shadows an earlier one kernel/posix-cpu-timers.c:1058:21: originally declared here Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * timer_list: add annotations to workqueue.cPavel Machek2008-04-17
| | | | | | | | | | | | | | | | Add timer list annotations to workqueue.c so we can see the call site in the timer stats. Signed-off-by: Pavel Machek <Pavel@suse.cz> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * hrtimer: use nanosleep specific restart_block fieldsThomas Gleixner2008-04-17
| | | | | | | | | | | | | | Convert all the nanosleep related users of restart_block to the new nanosleep specific restart_block fields. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | Merge git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-kgdbLinus Torvalds2008-04-18
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-kgdb: kgdb: always use icache flush for sw breakpoints kgdb: fix SMP NMI kgdb_handle_exception exit race kgdb: documentation fixes kgdb: allow static kgdbts boot configuration kgdb: add documentation kgdb: Kconfig fix kgdb: add kgdb internal test suite kgdb: fix several kgdb regressions kgdb: kgdboc pl011 I/O module kgdb: fix optional arch functions and probe_kernel_* kgdb: add x86 HW breakpoints kgdb: print breakpoint removed on exception kgdb: clocksource watchdog kgdb: fix NMI hangs kgdb: fix kgdboc dynamic module configuration kgdb: document parameters x86: kgdb support consoles: polling support, kgdboc kgdb: core uaccess: add probe_kernel_write()
| * | kgdb: always use icache flush for sw breakpointsJason Wessel2008-04-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | On the ppc 4xx architecture the instruction cache must be flushed as well as the data cache. This patch just makes it generic for all architectures where CACHE_FLUSH_IS_SAFE is set to 1. Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | kgdb: fix SMP NMI kgdb_handle_exception exit raceJason Wessel2008-04-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix the problem of protecting the kgdb handle_exception exit which had an NMI race condition, while trying to restore normal system operation. There was a small window after the master processor sets cpu_in_debug to zero but before it has set kgdb_active to zero where a non-master processor in an SMP system could receive an NMI and re-enter the kgdb_wait() loop. As long as the master processor sets the cpu_in_debug before sending the cpu roundup the cpu_in_debug variable can also be used to guard against the race condition. The kgdb_wait() function no longer needs to check kgdb_active because it is done in the arch specific code and handled along with the nmi traps at the low level. This also allows kgdb_wait() to exit correctly if it was entered for some unknown reason due to a spurious NMI that could not be handled by the arch specific code. Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | kgdb: fix several kgdb regressionsJason Wessel2008-04-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kgdb core fixes: - Check to see that mm->mmap_cache is not null before calling flush_cache_range(), else on arch=ARM it will cause a fatal fault. - Breakpoints should only be restored if they are in the BP_ACTIVE state. - Fix a typo in comments to "kgdb_register_io_module" x86 kgdb fixes: - Fix the x86 arch handler such that on a kill or detach that the appropriate cleanup on the single stepping flags gets run. - Add in the DIE_NMIWATCHDOG call for x86_64 - Touch the nmi watchdog before returning the system to normal operation after performing any kind of kgdb operation, else the possibility exists to trigger the watchdog. Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | kgdb: fix optional arch functions and probe_kernel_*Jason Wessel2008-04-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix two regressions dealing with the kgdb core. 1) kgdb_skipexception and kgdb_post_primary_code are optional functions that are only required on archs that need special exception fixups. 2) The kernel address space scope must be set on any probe_kernel_* function or archs such as ARCH=arm will not allow access to the kernel memory space. As an example, it is required to allow the full kernel address space is when you the kernel debugger to inspect a system call. Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | kgdb: add x86 HW breakpointsJason Wessel2008-04-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add HW breakpoints into the arch specific portion of x86 kgdb. In the current x86 kernel.org kernels HW breakpoints are changed out in lazy fashion because there is no infrastructure around changing them when changing to a kernel task or entering the kernel mode via a system call. This lazy approach means that if a user process uses HW breakpoints the kgdb will loose out. This is an acceptable trade off because the developer debugging the kernel is assumed to know what is going on system wide and would be aware of this trade off. There is a minor bug fix to the kgdb core so as to correctly call the hw breakpoint functions with a valid value from the enum. There is also a minor change to the x86_64 startup code when using early HW breakpoints. When the debugger is connected, the cpu startup code must not zero out the HW breakpoint registers or you cannot hit the breakpoints you are interested in, in the first place. Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | kgdb: print breakpoint removed on exceptionJason Wessel2008-04-17
| | | | | | | | | | | | | | | | | | | | | | | | If kgdb does remove a breakpoint that had a problem on the recursion check, it should also print the address of the breakpoint. Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | kgdb: clocksource watchdogJason Wessel2008-04-17
| | | | | | | | | | | | | | | | | | | | | | | | In order to not trip the clocksource watchdog, kgdb must touch the clocksource watchdog on the return to normal system run state. Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | kgdb: coreJason Wessel2008-04-17
| |/ | | | | | | | | | | | | | | | | | | | | | | kgdb core code. Handles the protocol and the arch details. [ mingo@elte.hu: heavily modified, simplified and cleaned up. ] [ xemul@openvz.org: use find_task_by_pid_ns ] Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Jan Kiszka <jan.kiszka@web.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
* | Merge branch 'semaphore' of ↵Linus Torvalds2008-04-18
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/willy/misc * 'semaphore' of git://git.kernel.org/pub/scm/linux/kernel/git/willy/misc: Remove DEBUG_SEMAPHORE from Kconfig Improve semaphore documentation Simplify semaphore implementation Add down_timeout and change ACPI to use it Introduce down_killable() Generic semaphore implementation Add semaphore.h to kernel_lock.c Fix quota.h includes
| * | Improve semaphore documentationMatthew Wilcox2008-04-17
| | | | | | | | | | | | | | | | | | | | | | | | Move documentation from semaphore.h to semaphore.c as requested by Andrew Morton. Also reformat to kernel-doc style and add some more notes about the implementation. Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
| * | Simplify semaphore implementationMatthew Wilcox2008-04-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | By removing the negative values of 'count' and relying on the wait_list to indicate whether we have any waiters, we can simplify the implementation by removing the protection against an unlikely race condition. Thanks to David Howells for his suggestions. Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
| * | Add down_timeout and change ACPI to use itMatthew Wilcox2008-04-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | ACPI currently emulates a timeout for semaphores with calls to down_trylock and sleep. This produces horrible behaviour in terms of fairness and excessive wakeups. Now that we have a unified semaphore implementation, adding a real down_trylock is almost trivial. Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
| * | Introduce down_killable()Matthew Wilcox2008-04-17
| | | | | | | | | | | | | | | | | | down_killable() is the functional counterpart of mutex_lock_killable. Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
| * | Generic semaphore implementationMatthew Wilcox2008-04-17
| |/ | | | | | | | | | | | | | | | | | | | | Semaphores are no longer performance-critical, so a generic C implementation is better for maintainability, debuggability and extensibility. Thanks to Peter Zijlstra for fixing the lockdep warning. Thanks to Harvey Harrison for pointing out that the unlikely() was unnecessary. Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Acked-by: Ingo Molnar <mingo@elte.hu>
* | Merge branch 'for-linus' of git://git390.osdl.marist.edu/pub/scm/linux-2.6Linus Torvalds2008-04-18
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'for-linus' of git://git390.osdl.marist.edu/pub/scm/linux-2.6: (36 commits) [S390] Remove code duplication from monreader / dcssblk. [S390] kernel: show last breaking-event-address on oops [S390] lowcore: Change type of lowcores softirq_pending to __u32. [S390] zcrypt: Comments and kernel-doc cleanup [S390] uaccess: Always access the correct address space. [S390] Fix a lot of sparse warnings. [S390] Convert s390 to GENERIC_CLOCKEVENTS. [S390] genirq/clockevents: move irq affinity prototypes/inlines to interrupt.h [S390] Convert monitor calls to function calls. [S390] qdio (new feature): enhancing info-retrieval from QDIO-adapters [S390] replace remaining __FUNCTION__ occurrences [S390] remove redundant display of free swap space in show_mem() [S390] qdio: remove outdated developerworks link. [S390] Add debug_register_mode() function to debug feature API [S390] crypto: use more descriptive function names for init/exit routines. [S390] switch sched_clock to store-clock-extended. [S390] zcrypt: add support for large random numbers [S390] hw_random: allow rng_dev_read() to return hardware errors. [S390] Vertical cpu management. [S390] cpu topology support for s390. ...
| * | [S390] genirq/clockevents: move irq affinity prototypes/inlines to interrupt.hRussell King2008-04-17
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | > Generic code is not supposed to include irq.h. Replace this include > by linux/hardirq.h instead and add/replace an include of linux/irq.h > in asm header files where necessary. > This change should only matter for architectures that make use of > GENERIC_CLOCKEVENTS. > Architectures in question are mips, x86, arm, sh, powerpc, uml and sparc64. > > I did some cross compile tests for mips, x86_64, arm, powerpc and sparc64. > This patch fixes also build breakages caused by the include replacement in > tick-common.h. I generally dislike adding optional linux/* includes in asm/* includes - I'm nervous about this causing include loops. However, there's a separate point to be discussed here. That is, what interfaces are expected of every architecture in the kernel. If generic code wants to be able to set the affinity of interrupts, then that needs to become part of the interfaces listed in linux/interrupt.h rather than linux/irq.h. So what I suggest is this approach instead (against Linus' tree of a couple of days ago) - we move irq_set_affinity() and irq_can_set_affinity() to linux/interrupt.h, change the linux/irq.h includes to linux/interrupt.h and include asm/irq_regs.h where needed (asm/irq_regs.h is supposed to be rarely used include since not much touches the stacked parent context registers.) Build tested on ARM PXA family kernels and ARM's Realview platform kernels which both use genirq. [ tglx@linutronix.de: add GENERIC_HARDIRQ dependencies ] Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
* | ptrace_signal subroutineRoland McGrath2008-04-18
| | | | | | | | | | | | | | | | | | | | | | | | | | This breaks out the ptrace handling from get_signal_to_deliver into a new subroutine. The actual code there doesn't change, and it gets inlined into nearly identical compiled code. This makes the function substantially shorter and thus easier to read, and it nicely isolates the ptrace magic. Signed-off-by: Roland McGrath <roland@redhat.com> Acked-by: Kyle McMartin <kyle@mcmartin.ca> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | cgroup: fix a race condition in manipulating tsk->cg_listLi Zefan2008-04-18
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When I ran a test program to fork mass processes and at the same time 'cat /cgroup/tasks', I got the following oops: ------------[ cut here ]------------ kernel BUG at lib/list_debug.c:72! invalid opcode: 0000 [#1] SMP Pid: 4178, comm: a.out Not tainted (2.6.25-rc9 #72) ... Call Trace: [<c044a5f9>] ? cgroup_exit+0x55/0x94 [<c0427acf>] ? do_exit+0x217/0x5ba [<c0427ed7>] ? do_group_exit+0.65/0x7c [<c0427efd>] ? sys_exit_group+0xf/0x11 [<c0404842>] ? syscall_call+0x7/0xb [<c05e0000>] ? init_cyrix+0x2fa/0x479 ... EIP: [<c04df671>] list_del+0x35/0x53 SS:ESP 0068:ebc7df4 ---[ end trace caffb7332252612b ]--- Fixing recursive fault but reboot is needed! After digging into the code and debugging, I finlly found out a race situation: do_exit() ->cgroup_exit() ->if (!list_empty(&tsk->cg_list)) list_del(&tsk->cg_list); cgroup_iter_start() ->cgroup_enable_task_cg_list() ->list_add(&tsk->cg_list, ..); In this case the list won't be deleted though the process has exited. We got two bug reports in the past, which seem to be the same bug as this one: http://lkml.org/lkml/2008/3/5/332 http://lkml.org/lkml/2007/10/17/224 Actually sometimes I got oops on list_del, sometimes oops on list_add. And I can change my test program a bit to trigger other oops. The patch has been tested both on x86_32 and x86_64. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Paul Menage <menage@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Fix locking bug in "acquire_console_semaphore_for_printk()"Linus Torvalds2008-04-15
| | | | | | | | | | | | | | | | | | | When I cleaned up printk() and split up the printk locking logic in commit 266c2e0abeca649fa6667a1a427ad1da507c6375 ("Make printk() console semaphore accesses sensible") I had incorrectly moved the call to have_callable_console() outside of the console semaphore. That was buggy. The console semaphore protects the console_drivers list that is used by have_callable_console(). Thanks go to Bongani Hlope who saw this as a hang on shutdown and reboot and bisected the bug to the right commit, and tested this patch. See http://lkml.org/lkml/2008/4/11/315 Bisected-and-tested-by: Bongani Hlope <bonganilinux@mweb.co.za> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* revert "sched: fix fair sleepers"Ingo Molnar2008-04-14
| | | | | | | | | | | | | revert "sched: fix fair sleepers" (e22ecef1d2658ba54ed7d3fdb5d60829fb434c23), because it is causing audio skipping, see: http://bugzilla.kernel.org/show_bug.cgi?id=10428 the patch is correct and the real cause of the skipping is not understood (tracing makes it go away), but time has run out so we'll revert it and re-try in 2.6.26. Signed-off-by: Ingo Molnar <mingo@elte.hu>
* cgroups: include hierarchy ids in /proc/<pid>/cgroupPaul Menage2008-04-11
| | | | | | | | | | | | | | | | | | Extend the /proc/<pid>/cgroup file to include the appropriate hierarchy ID on each line. Currently this ID isn't really needed since a hierarchy can be completely identified by the set of subsystems bound to it, but this is likely to change in the near future in order to support stateless subsystems and merging/rebinding of subsystems. Getting this change into 2.6.25 reduces the need for an API change later. Signed-off-by: Paul Menage <menage@google.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: 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>
* asmlinkage_protect replaces prevent_tail_callRoland McGrath2008-04-10
| | | | | | | | | | | | | | | | | | | | | | The prevent_tail_call() macro works around the problem of the compiler clobbering argument words on the stack, which for asmlinkage functions is the caller's (user's) struct pt_regs. The tail/sibling-call optimization is not the only way that the compiler can decide to use stack argument words as scratch space, which we have to prevent. Other optimizations can do it too. Until we have new compiler support to make "asmlinkage" binding on the compiler's own use of the stack argument frame, we have work around all the manifestations of this issue that crop up. More cases seem to be prevented by also keeping the incoming argument variables live at the end of the function. This makes their original stack slots attractive places to leave those variables, so the compiler tends not clobber them for something else. It's still no guarantee, but it handles some observed cases that prevent_tail_call() did not. Signed-off-by: Roland McGrath <roland@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* cgroups: add cgroup support for enabling controllers at boot timePaul Menage2008-04-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The effects of cgroup_disable=foo are: - foo isn't auto-mounted if you mount all cgroups in a single hierarchy - foo isn't visible as an individually mountable subsystem As a result there will only ever be one call to foo->create(), at init time; all processes will stay in this group, and the group will never be mounted on a visible hierarchy. Any additional effects (e.g. not allocating metadata) are up to the foo subsystem. This doesn't handle early_init subsystems (their "disabled" bit isn't set be, but it could easily be extended to do so if any of the early_init systems wanted it - I think it would just involve some nastier parameter processing since it would occur before the command-line argument parser had been run. Hugh said: Ballpark figures, I'm trying to get this question out rather than processing the exact numbers: CONFIG_CGROUP_MEM_RES_CTLR adds 15% overhead to the affected paths, booting with cgroup_disable=memory cuts that back to 1% overhead (due to slightly bigger struct page). I'm no expert on distros, they may have no interest whatever in CONFIG_CGROUP_MEM_RES_CTLR=y; and the rest of us can easily build with or without it, or apply the cgroup_disable=memory patches. Unix bench's execl test result on x86_64 was == just after boot without mounting any cgroup fs.== mem_cgorup=off : Execl Throughput 43.0 3150.1 732.6 mem_cgroup=on : Execl Throughput 43.0 2932.6 682.0 == [lizf@cn.fujitsu.com: fix boot option parsing] Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hugh@veritas.com> Cc: Sudhir Kumar <skumar@linux.vnet.ibm.com> Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* markers: use synchronize_sched()Mathieu Desnoyers2008-04-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Markers do not mix well with CONFIG_PREEMPT_RCU because it uses preempt_disable/enable() and not rcu_read_lock/unlock for minimal intrusiveness. We would need call_sched and sched_barrier primitives. Currently, the modification (connection and disconnection) of probes from markers requires changes to the data structure done in RCU-style : a new data structure is created, the pointer is changed atomically, a quiescent state is reached and then the old data structure is freed. The quiescent state is reached once all the currently running preempt_disable regions are done running. We use the call_rcu mechanism to execute kfree() after such quiescent state has been reached. However, the new CONFIG_PREEMPT_RCU version of call_rcu and rcu_barrier does not guarantee that all preempt_disable code regions have finished, hence the race. The "proper" way to do this is to use rcu_read_lock/unlock, but we don't want to use it to minimize intrusiveness on the traced system. (we do not want the marker code to call into much of the OS code, because it would quickly restrict what can and cannot be instrumented, such as the scheduler). The temporary fix, until we get call_rcu_sched and rcu_barrier_sched in mainline, is to use synchronize_sched before each call_rcu calls, so we wait for the quiescent state in the system call code path. It will slow down batch marker enable/disable, but will make sure the race is gone. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* futex_compat __user annotationAl Viro2008-03-30
| | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* NULL noise: fs/*, mm/*, kernel/*Al Viro2008-03-30
| | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* audit: silence two kerneldoc warnings in kernel/audit.cDave Jones2008-03-28
| | | | | | | | | | | | | | | Silence two kerneldoc warnings. Warning(kernel/audit.c:1276): No description found for parameter 'string' Warning(kernel/audit.c:1276): No description found for parameter 'len' [also fix a typo for bonus points] Signed-off-by: Dave Jones <davej@codemonkey.org.uk> Acked-by: Randy Dunlap <randy.dunlap@oracle.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memcgroup: fix spurious EBUSY on memory cgroup removalYAMAMOTO Takashi2008-03-28
| | | | | | | | | | | | Call mm_free_cgroup earlier. Otherwise a reference due to lazy mm switching can prevent cgroup removal. Signed-off-by: YAMAMOTO Takashi <yamamoto@valinux.co.jp> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Give futex init a proper nameBenjamin Herrenschmidt2008-03-27
| | | | | | | | | | The futex init function is called init(). This is a pain in the neck when debugging when you code dies in ... init :-) This renames it to futex_init(). Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'master' of ↵Linus Torvalds2008-03-26
|\ | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tglx/linux-2.6-hrt * 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/tglx/linux-2.6-hrt: NOHZ: reevaluate idle sleep length after add_timer_on() clocksource: revert: use init_timer_deferrable for clocksource_watchdog
| * NOHZ: reevaluate idle sleep length after add_timer_on()Thomas Gleixner2008-03-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | add_timer_on() can add a timer on a CPU which is currently in a long idle sleep, but the timer wheel is not reevaluated by the nohz code on that CPU. So a timer can be delayed for quite a long time. This triggered a false positive in the clocksource watchdog code. To avoid this we need to wake up the idle CPU and enforce the reevaluation of the timer wheel for the next timer event. Add a function, which checks a given CPU for idle state, marks the idle task with NEED_RESCHED and sends a reschedule IPI to notify the other CPU of the change in the timer wheel. Call this function from add_timer_on(). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: stable@kernel.org -- include/linux/sched.h | 6 ++++++ kernel/sched.c | 43 +++++++++++++++++++++++++++++++++++++++++++ kernel/timer.c | 10 +++++++++- 3 files changed, 58 insertions(+), 1 deletion(-)
| * clocksource: revert: use init_timer_deferrable for clocksource_watchdogThomas Gleixner2008-03-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Revert commit 1077f5a917b7c630231037826b344b2f7f5b903f Author: Parag Warudkar <parag.warudkar@gmail.com> Date: Wed Jan 30 13:30:01 2008 +0100 clocksource.c: use init_timer_deferrable for clocksource_watchdog clocksource_watchdog can use a deferrable timer - reduces wakeups from idle per second. The watchdog timer needs to run with the specified interval. Otherwise it will miss the possible wrap of the watchdog clocksource. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@kernel.org
* | relay: set an spd_release() hook for spliceJens Axboe2008-03-26
| | | | | | | | | | | | | | relay doesn't reference the pages it adds, however we need a non-NULL hook or splice_to_pipe() can oops. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* | set relay file can not be read by pread(2)Lai Jiangshan2008-03-26
|/ | | | | | | | I found that relay files can be read by pread(2). I fix it, for relay files are not capable of seeking. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* Make printk() console semaphore accesses sensibleLinus Torvalds2008-03-24
| | | | | | | | The printk() logic on when/how to get the console semaphore was unreadable, this splits the code up into a few helper functions and makes it easier to follow what is going on. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* bsd_acct: using task_struct->tgid is not right in pid-namespacesPavel Emelyanov2008-03-24
| | | | | | | | | | | | | | | | In case we're accounting from a sub-namespace, the tgids reported will not refer to the right namespace. Save the pid_namespace we're accounting in on the acct_glbs and use it in do_acct_process. Two less :) places using the task_struct.tgid member. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* bsd_acct: plain current->real_parent access is not always safePavel Emelyanov2008-03-24
| | | | | | | | | | | | | | | This is minor, but dereferencing even current real_parent is not safe on debug kernels, since the memory, this points to, can be unmapped - RCU protection is required. Besides, the tgid field is deprecated and is to be replaced with task_tgid_xxx call (the 2nd patch), so RCU will be required anyway. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>