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* CRED: Fix get_task_cred() and task_state() to not resurrect dead credentialsDavid Howells2010-07-291-0/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It's possible for get_task_cred() as it currently stands to 'corrupt' a set of credentials by incrementing their usage count after their replacement by the task being accessed. What happens is that get_task_cred() can race with commit_creds(): TASK_1 TASK_2 RCU_CLEANER -->get_task_cred(TASK_2) rcu_read_lock() __cred = __task_cred(TASK_2) -->commit_creds() old_cred = TASK_2->real_cred TASK_2->real_cred = ... put_cred(old_cred) call_rcu(old_cred) [__cred->usage == 0] get_cred(__cred) [__cred->usage == 1] rcu_read_unlock() -->put_cred_rcu() [__cred->usage == 1] panic() However, since a tasks credentials are generally not changed very often, we can reasonably make use of a loop involving reading the creds pointer and using atomic_inc_not_zero() to attempt to increment it if it hasn't already hit zero. If successful, we can safely return the credentials in the knowledge that, even if the task we're accessing has released them, they haven't gone to the RCU cleanup code. We then change task_state() in procfs to use get_task_cred() rather than calling get_cred() on the result of __task_cred(), as that suffers from the same problem. Without this change, a BUG_ON in __put_cred() or in put_cred_rcu() can be tripped when it is noticed that the usage count is not zero as it ought to be, for example: kernel BUG at kernel/cred.c:168! invalid opcode: 0000 [#1] SMP last sysfs file: /sys/kernel/mm/ksm/run CPU 0 Pid: 2436, comm: master Not tainted 2.6.33.3-85.fc13.x86_64 #1 0HR330/OptiPlex 745 RIP: 0010:[<ffffffff81069881>] [<ffffffff81069881>] __put_cred+0xc/0x45 RSP: 0018:ffff88019e7e9eb8 EFLAGS: 00010202 RAX: 0000000000000001 RBX: ffff880161514480 RCX: 00000000ffffffff RDX: 00000000ffffffff RSI: ffff880140c690c0 RDI: ffff880140c690c0 RBP: ffff88019e7e9eb8 R08: 00000000000000d0 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000040 R12: ffff880140c690c0 R13: ffff88019e77aea0 R14: 00007fff336b0a5c R15: 0000000000000001 FS: 00007f12f50d97c0(0000) GS:ffff880007400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f8f461bc000 CR3: 00000001b26ce000 CR4: 00000000000006f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process master (pid: 2436, threadinfo ffff88019e7e8000, task ffff88019e77aea0) Stack: ffff88019e7e9ec8 ffffffff810698cd ffff88019e7e9ef8 ffffffff81069b45 <0> ffff880161514180 ffff880161514480 ffff880161514180 0000000000000000 <0> ffff88019e7e9f28 ffffffff8106aace 0000000000000001 0000000000000246 Call Trace: [<ffffffff810698cd>] put_cred+0x13/0x15 [<ffffffff81069b45>] commit_creds+0x16b/0x175 [<ffffffff8106aace>] set_current_groups+0x47/0x4e [<ffffffff8106ac89>] sys_setgroups+0xf6/0x105 [<ffffffff81009b02>] system_call_fastpath+0x16/0x1b Code: 48 8d 71 ff e8 7e 4e 15 00 85 c0 78 0b 8b 75 ec 48 89 df e8 ef 4a 15 00 48 83 c4 18 5b c9 c3 55 8b 07 8b 07 48 89 e5 85 c0 74 04 <0f> 0b eb fe 65 48 8b 04 25 00 cc 00 00 48 3b b8 58 04 00 00 75 RIP [<ffffffff81069881>] __put_cred+0xc/0x45 RSP <ffff88019e7e9eb8> ---[ end trace df391256a100ebdd ]--- Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* dynamic debug: move ddebug_remove_module() down into free_module()Jason Baron2010-07-271-1/+3
| | | | | | | | | | | | | | | | | | | The command echo "file ec.c +p" >/sys/kernel/debug/dynamic_debug/control causes an oops. Move the call to ddebug_remove_module() down into free_module(). In this way it should be called from all error paths. Currently, we are missing the remove if the module init routine fails. Signed-off-by: Jason Baron <jbaron@redhat.com> Reported-by: Thomas Renninger <trenn@suse.de> Tested-by: Thomas Renninger <trenn@suse.de> Cc: <stable@kernel.org> [2.6.32+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sysrq,kdb: Use __handle_sysrq() for kdb's sysrq functionJason Wessel2010-07-211-2/+1
| | | | | | | | The kdb code should not toggle the sysrq state in case an end user wants to try and resume the normal kernel execution. Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
* debug_core,kdb: fix kgdb_connected bit set in the wrong placeJason Wessel2010-07-211-1/+1
| | | | | | | | | | | | Immediately following an exit from the kdb shell the kgdb_connected variable should be set to zero, unless there are breakpoints planted. If the kgdb_connected variable is not zeroed out with kdb, it is impossible to turn off kdb. This patch is merely a work around for now, the real fix will check for the breakpoints. Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
* Fix merge regression from external kdb to upstream kdbJason Wessel2010-07-211-0/+1
| | | | | | | | | | | In the process of merging kdb to the mainline, the kdb lsmod command stopped printing the base load address of kernel modules. This is needed for using kdb in conjunction with external tools such as gdb. Simply restore the functionality by adding a kdb_printf for the base load address of the kernel modules. Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
* repair gdbstub to match the gdbserial protocol specificationJason Wessel2010-07-211-6/+3
| | | | | | | | | | | | | | | The gdbserial protocol handler should return an empty packet instead of an error string when ever it responds to a command it does not implement. The problem cases come from a debugger client sending qTBuffer, qTStatus, qSearch, qSupported. The incorrect response from the gdbstub leads the debugger clients to not function correctly. Recent versions of gdb will not detach correctly as a result of this behavior. Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Signed-off-by: Dongdong Deng <dongdong.deng@windriver.com>
* kdb: break out of kdb_ll() when command is terminatedMartin Hicks2010-07-211-0/+3
| | | | | | | | Without this patch the "ll" linked-list traversal command won't terminate when you hit q/Q. Signed-off-by: Martin Hicks <mort@sgi.com> Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
* kmemleak: Add support for NO_BOOTMEM configurationsCatalin Marinas2010-07-191-0/+6
| | | | | | | | | | | | | With commits 08677214 and 59be5a8e, alloc_bootmem()/free_bootmem() and friends use the early_res functions for memory management when NO_BOOTMEM is enabled. This patch adds the kmemleak calls in the corresponding code paths for bootmem allocations. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Acked-by: Yinghai Lu <yinghai@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: stable@kernel.org
* module: initialize module dynamic debug laterYehuda Sadeh2010-07-041-8/+15
| | | | | | | | | | | | | We should initialize the module dynamic debug datastructures only after determining that the module is not loaded yet. This fixes a bug that introduced in 2.6.35-rc2, where when a trying to load a module twice, we also load it's dynamic printing data twice which causes all sorts of nasty issues. Also handle the dynamic debug cleanup later on failure. Signed-off-by: Yehuda Sadeh <yehuda@hq.newdream.net> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (removed a #ifdef) Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'sched-fixes-for-linus' of ↵Linus Torvalds2010-07-022-10/+10
|\ | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: sched: Cure nr_iowait_cpu() users init: Fix comment init, sched: Fix race between init and kthreadd
| * sched: Cure nr_iowait_cpu() usersPeter Zijlstra2010-07-012-10/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 0224cf4c5e (sched: Intoduce get_cpu_iowait_time_us()) broke things by not making sure preemption was indeed disabled by the callers of nr_iowait_cpu() which took the iowait value of the current cpu. This resulted in a heap of preempt warnings. Cure this by making nr_iowait_cpu() take a cpu number and fix up the callers to pass in the right number. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Arjan van de Ven <arjan@infradead.org> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Maxim Levitsky <maximlevitsky@gmail.com> Cc: Len Brown <len.brown@intel.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Jiri Slaby <jslaby@suse.cz> Cc: linux-pm@lists.linux-foundation.org LKML-Reference: <1277968037.1868.120.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | futex: futex_find_get_task remove credentails checkMichal Hocko2010-06-301-13/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | futex_find_get_task is currently used (through lookup_pi_state) from two contexts, futex_requeue and futex_lock_pi_atomic. None of the paths looks it needs the credentials check, though. Different (e)uids shouldn't matter at all because the only thing that is important for shared futex is the accessibility of the shared memory. The credentail check results in glibc assert failure or process hang (if glibc is compiled without assert support) for shared robust pthread mutex with priority inheritance if a process tries to lock already held lock owned by a process with a different euid: pthread_mutex_lock.c:312: __pthread_mutex_lock_full: Assertion `(-(e)) != 3 || !robust' failed. The problem is that futex_lock_pi_atomic which is called when we try to lock already held lock checks the current holder (tid is stored in the futex value) to get the PI state. It uses lookup_pi_state which in turn gets task struct from futex_find_get_task. ESRCH is returned either when the task is not found or if credentials check fails. futex_lock_pi_atomic simply returns if it gets ESRCH. glibc code, however, doesn't expect that robust lock returns with ESRCH because it should get either success or owner died. Signed-off-by: Michal Hocko <mhocko@suse.cz> Acked-by: Darren Hart <dvhltc@us.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Nick Piggin <npiggin@suse.de> Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | kexec: fix Oops in crash_shrink_memory()Pavan Naregundi2010-06-291-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When crashkernel is not enabled, "echo 0 > /sys/kernel/kexec_crash_size" OOPSes the kernel in crash_shrink_memory. This happens when crash_shrink_memory tries to release the 'crashk_res' resource which are not reserved. Also value of "/sys/kernel/kexec_crash_size" shows as 1, which should be 0. This patch fixes the OOPS in crash_shrink_memory and shows "/sys/kernel/kexec_crash_size" as 0 when crash kernel memory is not reserved. Signed-off-by: Pavan Naregundi <pavan@linux.vnet.ibm.com> Reviewed-by: WANG Cong <xiyou.wangcong@gmail.com> Cc: Simon Horman <horms@verge.net.au> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Merge branch 'perf-fixes-for-linus' of ↵Linus Torvalds2010-06-281-1/+3
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: tracing: Fix undeclared ENOSYS in include/linux/tracepoint.h perf record: prevent kill(0, SIGTERM); perf session: Remove threads from tree on PERF_RECORD_EXIT perf/tracing: Fix regression of perf losing kprobe events perf_events: Fix Intel Westmere event constraints perf record: Don't call newt functions when not initialized
| * | perf/tracing: Fix regression of perf losing kprobe eventsSteven Rostedt2010-06-101-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With the addition of the code to shrink the kernel tracepoint infrastructure, we lost kprobes being traced by perf. The reason is that I tested if the "tp_event->class->perf_probe" existed before enabling it. This prevents "ftrace only" events (like the function trace events) from being enabled by perf. Unfortunately, kprobe events do not use perf_probe. This causes kprobes to be missed by perf. To fix this, we add the test to see if "tp_event->class->reg" exists as well as perf_probe. Normal trace events have only "perf_probe" but no "reg" function, and kprobes and syscalls have the "reg" but no "perf_probe". The ftrace unique events do not have either, so this is a valid test. If a kprobe or syscall is not to be probed by perf, the "reg" function is called anyway, and will return a failure and prevent perf from probing it. Reported-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Tested-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | | Merge branch 'irq-fixes-for-linus' of ↵Linus Torvalds2010-06-281-0/+3
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'irq-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: genirq: Deal with desc->set_type() changing desc->chip
| * | | genirq: Deal with desc->set_type() changing desc->chipThomas Gleixner2010-06-091-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The set_type() function can change the chip implementation when the trigger mode changes. That might result in using an non-initialized irq chip when called from __setup_irq() or when called via set_irq_type() on an already enabled irq. The set_irq_type() function should not be called on an enabled irq, but because we forgot to put a check into it, we have a bunch of users which grew the habit of doing that and it never blew up as the function is serialized via desc->lock against all users of desc->chip and they never hit the non-initialized irq chip issue. The easy fix for the __setup_irq() issue would be to move the irq_chip_set_defaults(desc->chip) call after the trigger setting to make sure that a chip change is covered. But as we have already users, which do the type setting after request_irq(), the safe fix for now is to call irq_chip_set_defaults() from __irq_set_trigger() when desc->set_type() changed the irq chip. It needs a deeper analysis whether we should refuse to change the chip on an already enabled irq, but that'd be a large scale change to fix all the existing users. So that's neither stable nor 2.6.35 material. Reported-by: Esben Haabendal <eha@doredevelopment.dk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: linuxppc-dev <linuxppc-dev@ozlabs.org> Cc: stable@kernel.org
* | | | Merge branch 'sched-fixes-for-linus' of ↵Linus Torvalds2010-06-281-59/+65
|\ \ \ \ | | |_|/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: sched: Prevent compiler from optimising the sched_avg_update() loop sched: Fix over-scheduling bug sched: Fix PROVE_RCU vs cpu_cgroup
| * | | sched: Prevent compiler from optimising the sched_avg_update() loopWill Deacon2010-06-251-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | GCC 4.4.1 on ARM has been observed to replace the while loop in sched_avg_update with a call to uldivmod, resulting in the following build failure at link-time: kernel/built-in.o: In function `sched_avg_update': kernel/sched.c:1261: undefined reference to `__aeabi_uldivmod' kernel/sched.c:1261: undefined reference to `__aeabi_uldivmod' make: *** [.tmp_vmlinux1] Error 1 This patch introduces a fake data hazard to the loop body to prevent the compiler optimising the loop away. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: <stable@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | sched: Fix over-scheduling bugAlex,Shi2010-06-181-3/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit e70971591 ("sched: Optimize unused cgroup configuration") introduced an imbalanced scheduling bug. If we do not use CGROUP, function update_h_load won't update h_load. When the system has a large number of tasks far more than logical CPU number, the incorrect cfs_rq[cpu]->h_load value will cause load_balance() to pull too many tasks to the local CPU from the busiest CPU. So the busiest CPU keeps going in a round robin. That will hurt performance. The issue was found originally by a scientific calculation workload that developed by Yanmin. With that commit, the workload performance drops about 40%. CPU before after 00 : 2 : 7 01 : 1 : 7 02 : 11 : 6 03 : 12 : 7 04 : 6 : 6 05 : 11 : 7 06 : 10 : 6 07 : 12 : 7 08 : 11 : 6 09 : 12 : 6 10 : 1 : 6 11 : 1 : 6 12 : 6 : 6 13 : 2 : 6 14 : 2 : 6 15 : 1 : 6 Reviewed-by: Yanmin zhang <yanmin.zhang@intel.com> Signed-off-by: Alex Shi <alex.shi@intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1276754893.9452.5442.camel@debian> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | sched: Fix PROVE_RCU vs cpu_cgroupPeter Zijlstra2010-06-081-56/+59
| |/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | PROVE_RCU has a few issues with the cpu_cgroup because the scheduler typically holds rq->lock around the css rcu derefs but the generic cgroup code doesn't (and can't) know about that lock. Provide means to add extra checks to the css dereference and use that in the scheduler to annotate its users. The addition of rq->lock to these checks is correct because the cgroup_subsys::attach() method takes the rq->lock for each task it moves, therefore by holding that lock, we ensure the task is pinned to the current cgroup and the RCU derefence is valid. That leaves one genuine race in __sched_setscheduler() where we used task_group() without holding any of the required locks and thus raced with the cgroup code. Solve this by moving the check under the appropriate lock. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | Merge branch 'timers-fixes-for-linus' of ↵Linus Torvalds2010-06-281-4/+1
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: nohz: Fix nohz ratelimit
| * | | nohz: Fix nohz ratelimitPeter Zijlstra2010-06-171-4/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Chris Wedgwood reports that 39c0cbe (sched: Rate-limit nohz) causes a serial console regression, unresponsiveness, and indeed it does. The reason is that the nohz code is skipped even when the tick was already stopped before the nohz_ratelimit(cpu) condition changed. Move the nohz_ratelimit() check to the other conditions which prevent long idle sleeps. Reported-by: Chris Wedgwood <cw@f00f.org> Tested-by: Brian Bloniarz <bmb@athenacr.com> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Greg KH <gregkh@suse.de> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Cc: Jef Driesen <jefdriesen@telenet.be> LKML-Reference: <1276790557.27822.516.camel@twins> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | | | Merge branch 'core-fixes-for-linus' of ↵Linus Torvalds2010-06-282-0/+11
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: sched: silence PROVE_RCU in sched_fork() idr: fix RCU lockdep splat in idr_get_next() rcu: apply RCU protection to wake_affine()
| * | | | sched: silence PROVE_RCU in sched_fork()Peter Zijlstra2010-06-231-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Because cgroup_fork() is ran before sched_fork() [ from copy_process() ] and the child's pid is not yet visible the child is pinned to its cgroup. Therefore we can silence this warning. A nicer solution would be moving cgroup_fork() to right after dup_task_struct() and exclude PF_STARTING from task_subsys_state(). Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Reviewed-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| * | | | rcu: apply RCU protection to wake_affine()Daniel J Blueman2010-06-231-0/+2
| |/ / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The task_group() function returns a pointer that must be protected by either RCU, the ->alloc_lock, or the cgroup lock (see the rcu_dereference_check() in task_subsys_state(), which is invoked by task_group()). The wake_affine() function currently does none of these, which means that a concurrent update would be within its rights to free the structure returned by task_group(). Because wake_affine() uses this structure only to compute load-balancing heuristics, there is no reason to acquire either of the two locks. Therefore, this commit introduces an RCU read-side critical section that starts before the first call to task_group() and ends after the last use of the "tg" pointer returned from task_group(). Thanks to Li Zefan for pointing out the need to extend the RCU read-side critical section from that proposed by the original patch. Signed-off-by: Daniel J Blueman <daniel.blueman@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
* | | | Merge branch 'bugzilla-13931-sleep-nvs' into releaseLen Brown2010-06-124-17/+24
|\ \ \ \ | |/ / / |/| | | | | | | | | | | | | | | | | | | Conflicts: drivers/acpi/sleep.c Signed-off-by: Len Brown <len.brown@intel.com>
| * | | suspend: Move NVS save/restore code to generic suspend functionalityMatthew Garrett2010-06-104-17/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Saving platform non-volatile state may be required for suspend to RAM as well as hibernation. Move it to more generic code. Signed-off-by: Matthew Garrett <mjg@redhat.com> Acked-by: Rafael J. Wysocki <rjw@sisk.pl> Tested-by: Maxim Levitsky <maximlevitsky@gmail.com> Signed-off-by: Len Brown <len.brown@intel.com>
* | | | Merge branch 'perf-fixes-for-linus' of ↵Linus Torvalds2010-06-101-1/+4
|\ \ \ \ | |_|/ / |/| | / | | |/ | |/| | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: tracing: Fix null pointer deref with SEND_SIG_FORCED perf: Fix signed comparison in perf_adjust_period() powerpc/oprofile: fix potential buffer overrun in op_model_cell.c perf symbols: Set the DSO long name when using symbol_conf.vmlinux_name
| * | perf: Fix signed comparison in perf_adjust_period()Peter Zijlstra2010-06-081-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Frederic reported that frequency driven swevents didn't work properly and even caused a division-by-zero error. It turns out there are two bugs, the division-by-zero comes from a failure to deal with that in perf_calculate_period(). The other was more interesting and turned out to be a wrong comparison in perf_adjust_period(). The comparison was between an s64 and u64 and got implicitly converted to an unsigned comparison. The problem is that period_left is typically < 0, so it ended up being always true. Cure this by making the local period variables s64. Reported-by: Frederic Weisbecker <fweisbec@gmail.com> Tested-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: <stable@kernel.org> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linusLinus Torvalds2010-06-042-121/+211
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus: module: fix bne2 "gave up waiting for init of module libcrc32c" module: verify_export_symbols under the lock module: move find_module check to end module: make locking more fine-grained. module: Make module sysfs functions private. module: move sysfs exposure to end of load_module module: fix kdb's illicit use of struct module_use. module: Make the 'usage' lists be two-way
| * | | module: fix bne2 "gave up waiting for init of module libcrc32c"Rusty Russell2010-06-051-32/+59
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Problem: it's hard to avoid an init routine stumbling over a request_module these days. And it's not clear it's always a bad idea: for example, a module like kvm with dynamic dependencies on kvm-intel or kvm-amd would be neater if it could simply request_module the right one. In this particular case, it's libcrc32c: libcrc32c_mod_init crypto_alloc_shash crypto_alloc_tfm crypto_find_alg crypto_alg_mod_lookup crypto_larval_lookup request_module If another module is waiting inside resolve_symbol() for libcrc32c to finish initializing (ie. bne2 depends on libcrc32c) then it does so holding the module lock, and our request_module() can't make progress until that is released. Waiting inside resolve_symbol() without the lock isn't all that hard: we just need to pass the -EBUSY up the call chain so we can sleep where we don't hold the lock. Error reporting is a bit trickier: we need to copy the name of the unfinished module before releasing the lock. Other notes: 1) This also fixes a theoretical issue where a weak dependency would allow symbol version mismatches to be ignored. 2) We rename use_module to ref_module to make life easier for the only external user (the out-of-tree ksplice patches). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Tim Abbot <tabbott@ksplice.com> Tested-by: Brandon Philips <bphilips@suse.de>
| * | | module: verify_export_symbols under the lockRusty Russell2010-06-051-16/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It disabled preempt so it was "safe", but nothing stops another module slipping in before this module is added to the global list now we don't hold the lock the whole time. So we check this just after we check for duplicate modules, and just before we put the module in the global list. (find_symbol finds symbols in coming and going modules, too). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
| * | | module: move find_module check to endLinus Torvalds2010-06-051-5/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I think Rusty may have made the lock a bit _too_ finegrained there, and didn't add it to some places that needed it. It looks, for example, like PATCH 1/2 actually drops the lock in places where it's needed ("find_module()" is documented to need it, but now load_module() didn't hold it at all when it did the find_module()). Rather than adding a new "module_loading" list, I think we should be able to just use the existing "modules" list, and just fix up the locking a bit. In fact, maybe we could just move the "look up existing module" a bit later - optimistically assuming that the module doesn't exist, and then just undoing the work if it turns out that we were wrong, just before adding ourselves to the list. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
| * | | module: make locking more fine-grained.Rusty Russell2010-06-051-23/+42
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Kay Sievers <kay.sievers@vrfy.org> reports that we still have some contention over module loading which is slowing boot. Linus also disliked a previous "drop lock and regrab" patch to fix the bne2 "gave up waiting for init of module libcrc32c" message. This is more ambitious: we only grab the lock where we need it. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Brandon Philips <brandon@ifup.org> Cc: Kay Sievers <kay.sievers@vrfy.org> Cc: Linus Torvalds <torvalds@linux-foundation.org>
| * | | module: Make module sysfs functions private.Rusty Russell2010-06-051-4/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | These were placed in the header in ef665c1a06 to get the various SYSFS/MODULE config combintations to compile. That may have been necessary then, but it's not now. These functions are all local to module.c. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Randy Dunlap <randy.dunlap@oracle.com>
| * | | module: move sysfs exposure to end of load_moduleRusty Russell2010-06-051-11/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This means a little extra work, but is more logical: we don't put anything in sysfs until we're about to put the module into the global list an parse its parameters. This also gives us a logical place to put duplicate module detection in the next patch. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
| * | | module: fix kdb's illicit use of struct module_use.Rusty Russell2010-06-052-19/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Linus changed the structure, and luckily this didn't compile any more. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Martin Hicks <mort@sgi.com>
| * | | module: Make the 'usage' lists be two-wayLinus Torvalds2010-06-051-31/+48
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When adding a module that depends on another one, we used to create a one-way list of "modules_which_use_me", so that module unloading could see who needs a module. It's actually quite simple to make that list go both ways: so that we not only can see "who uses me", but also see a list of modules that are "used by me". In fact, we always wanted that list in "module_unload_free()": when we unload a module, we want to also release all the other modules that are used by that module. But because we didn't have that list, we used to first iterate over all modules, and then iterate over each "used by me" list of that module. By making the list two-way, we simplify module_unload_free(), and it allows for some trivial fixes later too. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (cleaned & rebased)
* | | | Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds2010-06-041-4/+4
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'for-linus' of git://git.kernel.dk/linux-2.6-block: (27 commits) block: make blk_init_free_list and elevator_init idempotent block: avoid unconditionally freeing previously allocated request_queue pipe: change /proc/sys/fs/pipe-max-pages to byte sized interface pipe: change the privilege required for growing a pipe beyond system max pipe: adjust minimum pipe size to 1 page block: disable preemption before using sched_clock() cciss: call BUG() earlier Preparing 8.3.8rc2 drbd: Reduce verbosity drbd: use drbd specific ratelimit instead of global printk_ratelimit drbd: fix hang on local read errors while disconnected drbd: Removed the now empty w_io_error() function drbd: removed duplicated #includes drbd: improve usage of MSG_MORE drbd: need to set socket bufsize early to take effect drbd: improve network latency, TCP_QUICKACK drbd: Revert "drbd: Create new current UUID as late as possible" brd: support discard Revert "writeback: fix WB_SYNC_NONE writeback from umount" Revert "writeback: ensure that WB_SYNC_NONE writeback with sb pinned is sync" ...
| * | | | pipe: change /proc/sys/fs/pipe-max-pages to byte sized interfaceJens Axboe2010-06-031-4/+4
| | |_|/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This changes the interface to be based on bytes instead. The API matches that of F_SETPIPE_SZ in that it rounds up the passed in size so that the resulting page array is a power-of-2 in size. The proc file is renamed to /proc/sys/fs/pipe-max-size to reflect this change. Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
* | | | kernel/: fix BUG_ON checks for cpu notifier callbacks direct callAkinobu Mita2010-06-042-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The commit 80b5184cc537718122e036afe7e62d202b70d077 ("kernel/: convert cpu notifier to return encapsulate errno value") changed the return value of cpu notifier callbacks. Those callbacks don't return NOTIFY_BAD on failures anymore. But there are a few callbacks which are called directly at init time and checking the return value. I forgot to change BUG_ON checking by the direct callers in the commit. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | cgroups: alloc_css_id() increments hierarchy depthGreg Thelen2010-06-041-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Child groups should have a greater depth than their parents. Prior to this change, the parent would incorrectly report zero memory usage for child cgroups when use_hierarchy is enabled. test script: mount -t cgroup none /cgroups -o memory cd /cgroups mkdir cg1 echo 1 > cg1/memory.use_hierarchy mkdir cg1/cg11 echo $$ > cg1/cg11/tasks dd if=/dev/zero of=/tmp/foo bs=1M count=1 echo echo CHILD grep cache cg1/cg11/memory.stat echo echo PARENT grep cache cg1/memory.stat echo $$ > tasks rmdir cg1/cg11 cg1 cd / umount /cgroups Using fae9c79, a recent patch that changed alloc_css_id() depth computation, the parent incorrectly reports zero usage: root@ubuntu:~# ./test 1+0 records in 1+0 records out 1048576 bytes (1.0 MB) copied, 0.0151844 s, 69.1 MB/s CHILD cache 1048576 total_cache 1048576 PARENT cache 0 total_cache 0 With this patch, the parent correctly includes child usage: root@ubuntu:~# ./test 1+0 records in 1+0 records out 1048576 bytes (1.0 MB) copied, 0.0136827 s, 76.6 MB/s CHILD cache 1052672 total_cache 1052672 PARENT cache 0 total_cache 1052672 Signed-off-by: Greg Thelen <gthelen@google.com> Acked-by: Paul Menage <menage@google.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Li Zefan <lizf@cn.fujitsu.com> Cc: <stable@kernel.org> [2.6.34.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | sys_personality: change sys_personality() to accept "unsigned int" instead ↵Oleg Nesterov2010-06-041-9/+9
| |/ / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | of u_long task_struct->pesonality is "unsigned int", but sys_personality() paths use "unsigned long pesonality". This means that every assignment or comparison is not right. In particular, if this argument does not fit into "unsigned int" __set_personality() changes the caller's personality and then sys_personality() returns -EINVAL. Turn this argument into "unsigned int" and avoid overflows. Obviously, this is the user-visible change, we just ignore the upper bits. But this can't break the sane application. There is another thing which can confuse the poorly written applications. User-space thinks that this syscall returns int, not long. This means that the returned value can be negative and look like the error code. But note that libc won't be confused and thus errno won't be set, and with this patch the user-space can never get -1 unless sys_personality() really fails. And, most importantly, the negative RET != -1 is only possible if that app previously called personality(RET). Pointed-out-by: Wenming Zhang <wezhang@redhat.com> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | Merge branch 'sched-fixes-for-linus' of ↵Linus Torvalds2010-06-033-25/+23
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: sched, trace: Fix sched_switch() prev_state argument sched: Fix wake_affine() vs RT tasks sched: Make sure timers have migrated before killing the migration_thread
| * | | sched: Fix wake_affine() vs RT tasksPeter Zijlstra2010-06-012-24/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Mike reports that since e9e9250b (sched: Scale down cpu_power due to RT tasks), wake_affine() goes funny on RT tasks due to them still having a !0 weight and wake_affine() still subtracts that from the rq weight. Since nobody should be using se->weight for RT tasks, set the value to zero. Also, since we now use ->cpu_power to normalize rq weights to account for RT cpu usage, add that factor into the imbalance computation. Reported-by: Mike Galbraith <efault@gmx.de> Tested-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1275316109.27810.22969.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | sched: Make sure timers have migrated before killing the migration_threadAmit K. Arora2010-05-311-1/+1
| |/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Problem: In a stress test where some heavy tests were running along with regular CPU offlining and onlining, a hang was observed. The system seems to be hung at a point where migration_call() tries to kill the migration_thread of the dying CPU, which just got moved to the current CPU. This migration thread does not get a chance to run (and die) since rt_throttled is set to 1 on current, and it doesn't get cleared as the hrtimer which is supposed to reset the rt bandwidth (sched_rt_period_timer) is tied to the CPU which we just marked dead! Solution: This patch pushes the killing of migration thread to "CPU_POST_DEAD" event. By then all the timers (including sched_rt_period_timer) should have got migrated (along with other callbacks). Signed-off-by: Amit Arora <aarora@in.ibm.com> Signed-off-by: Gautham R Shenoy <ego@in.ibm.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <20100525132346.GA14986@amitarora.in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | Merge branch 'perf-fixes-for-linus-2' of ↵Linus Torvalds2010-06-035-142/+234
|\ \ \ | | |/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perf-fixes-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: perf: Fix crash in swevents perf buildid-list: Fix --with-hits event processing perf scripts python: Give field dict to unhandled callback perf hist: fix objdump output parsing perf-record: Check correct pid when forking perf: Do the comm inheritance per thread in event__process_task perf: Use event__process_task from perf sched perf: Process comm events by tid blktrace: Fix new kernel-doc warnings perf_events: Fix unincremented buffer base on partial copy perf_events: Fix event scheduling issues introduced by transactional API perf_events, trace: Fix perf_trace_destroy(), mutex went missing perf_events, trace: Fix probe unregister race perf_events: Fix races in group composition perf_events: Fix races and clean up perf_event and perf_mmap_data interaction
| * | perf: Fix crash in sweventsPeter Zijlstra2010-06-031-9/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Frederic reported that because swevents handling doesn't disable IRQs anymore, we can get a recursion of perf_adjust_period(), once from overflow handling and once from the tick. If both call ->disable, we get a double hlist_del_rcu() and trigger a LIST_POISON2 dereference. Since we don't actually need to stop/start a swevent to re-programm the hardware (lack of hardware to program), simply nop out these callbacks for the swevent pmu. Reported-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1275557609.27810.35218.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | blktrace: Fix new kernel-doc warningsRandy Dunlap2010-05-311-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix blktrace.c kernel-doc warnings: Warning(kernel/trace/blktrace.c:858): No description found for parameter 'ignore' Warning(kernel/trace/blktrace.c:890): No description found for parameter 'ignore' Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <20100529114507.c466fc1e.randy.dunlap@oracle.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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