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2010-08-04Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6Linus Torvalds3-1/+68
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6: (1443 commits) phy/marvell: add 88ec048 support igb: Program MDICNFG register prior to PHY init e1000e: correct MAC-PHY interconnect register offset for 82579 hso: Add new product ID can: Add driver for esd CAN-USB/2 device l2tp: fix export of header file for userspace can-raw: Fix skb_orphan_try handling Revert "net: remove zap_completion_queue" net: cleanup inclusion phy/marvell: add 88e1121 interface mode support u32: negative offset fix net: Fix a typo from "dev" to "ndev" igb: Use irq_synchronize per vector when using MSI-X ixgbevf: fix null pointer dereference due to filter being set for VLAN 0 e1000e: Fix irq_synchronize in MSI-X case e1000e: register pm_qos request on hardware activation ip_fragment: fix subtracting PPPOE_SES_HLEN from mtu twice net: Add getsockopt support for TCP thin-streams cxgb4: update driver version cxgb4: add new PCI IDs ... Manually fix up conflicts in: - drivers/net/e1000e/netdev.c: due to pm_qos registration infrastructure changes - drivers/net/phy/marvell.c: conflict between adding 88ec048 support and cleaning up the IDs - drivers/net/wireless/ipw2x00/ipw2100.c: trivial ipw2100_pm_qos_req conflict (registration change vs marking it static)
2010-08-04CRED: Fix RCU warning due to previous patch fixing __task_cred()'s checksDavid Howells1-3/+6
Commit 8f92054e7ca1 ("CRED: Fix __task_cred()'s lockdep check and banner comment") fixed the lockdep checks on __task_cred(). This has shown up a place in the signalling code where a lock should be held - namely that check_kill_permission() requires its callers to hold the RCU lock. Fix group_send_sig_info() to get the RCU read lock around its call to check_kill_permission(). Without this patch, the following warning can occur: =================================================== [ INFO: suspicious rcu_dereference_check() usage. ] --------------------------------------------------- kernel/signal.c:660 invoked rcu_dereference_check() without protection! ... Reported-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-04Merge branch 'for-linus' of ↵Linus Torvalds5-117/+194
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6: PM / Runtime: Add runtime PM statistics (v3) PM / Runtime: Make runtime_status attribute not debug-only (v. 2) PM: Do not use dynamically allocated objects in pm_wakeup_event() PM / Suspend: Fix ordering of calls in suspend error paths PM / Hibernate: Fix snapshot error code path PM / Hibernate: Fix hibernation_platform_enter() pm_qos: Get rid of the allocation in pm_qos_add_request() pm_qos: Reimplement using plists plist: Add plist_last PM: Make it possible to avoid races between wakeup and system sleep PNPACPI: Add support for remote wakeup PM: describe kernel policy regarding wakeup defaults (v. 2) PM / Hibernate: Fix typos in comments in kernel/power/swap.c
2010-08-03timer: add on-stack deferrable timer interfacesJesse Barnes1-0/+13
In some cases (for instance with kernel threads) it may be desireable to use on-stack deferrable timers to get their power saving benefits. Add interfaces to support this for the IPS driver. Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org> Signed-off-by: Matthew Garrett <mjg@redhat.com>
2010-07-30CRED: Fix get_task_cred() and task_state() to not resurrect dead credentialsDavid Howells1-0/+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>
2010-07-28cgroups: Add an API to attach a task to current task's cgroupSridhar Samudrala1-0/+23
Add a new kernel API to attach a task to current task's cgroup in all the active hierarchies. Signed-off-by: Sridhar Samudrala <sri@us.ibm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Paul Menage <menage@google.com> Acked-by: Li Zefan <lizf@cn.fujitsu.com>
2010-07-28dynamic debug: move ddebug_remove_module() down into free_module()Jason Baron1-1/+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>
2010-07-22sysrq,kdb: Use __handle_sysrq() for kdb's sysrq functionJason Wessel1-2/+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>
2010-07-22debug_core,kdb: fix kgdb_connected bit set in the wrong placeJason Wessel1-1/+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>
2010-07-22Fix merge regression from external kdb to upstream kdbJason Wessel1-0/+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>
2010-07-22repair gdbstub to match the gdbserial protocol specificationJason Wessel1-6/+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>
2010-07-22kdb: break out of kdb_ll() when command is terminatedMartin Hicks1-0/+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>
2010-07-21drop_monitor: convert some kfree_skb call sites to consume_skbNeil Horman1-1/+1
Convert a few calls from kfree_skb to consume_skb Noticed while I was working on dropwatch that I was detecting lots of internal skb drops in several places. While some are legitimate, several were not, freeing skbs that were at the end of their life, rather than being discarded due to an error. This patch converts those calls sites from using kfree_skb to consume_skb, which quiets the in-kernel drop_monitor code from detecting them as drops. Tested successfully by myself Signed-off-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-07-19kmemleak: Add support for NO_BOOTMEM configurationsCatalin Marinas1-0/+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
2010-07-19PM / Suspend: Fix ordering of calls in suspend error pathsRafael J. Wysocki1-5/+4
The ACPI suspend code calls suspend_nvs_free() at a wrong place, which may lead to a memory leak if there's an error executing acpi_pm_prepare(), because acpi_pm_finish() will not be called in that case. However, the root cause of this problem is the apparently confusing ordering of calls in suspend error paths that needs to be fixed. In addition to that, fix a typo in a label name in suspend.c. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Len Brown <len.brown@intel.com>
2010-07-19PM / Hibernate: Fix snapshot error code pathRafael J. Wysocki1-1/+1
There is an inconsistency between hibernation_platform_enter() and hibernation_snapshot(), because the latter calls hibernation_ops->end() after failing hibernation_ops->begin(), while the former doesn't do that. Make hibernation_snapshot() behave in the same way as hibernation_platform_enter() in that respect. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Len Brown <len.brown@intel.com>
2010-07-19PM / Hibernate: Fix hibernation_platform_enter()Rafael J. Wysocki1-1/+1
The hibernation_platform_enter() function calls dpm_suspend_noirq() instead of dpm_resume_noirq() by mistake. Fix this. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Len Brown <len.brown@intel.com>
2010-07-19pm_qos: Get rid of the allocation in pm_qos_add_request()James Bottomley1-27/+40
All current users of pm_qos_add_request() have the ability to supply the memory required by the pm_qos routines, so make them do this and eliminate the kmalloc() with pm_qos_add_request(). This has the double benefit of making the call never fail and allowing it to be called from atomic context. Signed-off-by: James Bottomley <James.Bottomley@suse.de> Signed-off-by: mark gross <markgross@thegnar.org> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-07-19pm_qos: Reimplement using plistsJames Bottomley1-86/+86
A lot of the pm_qos extremal value handling is really duplicating what a priority ordered list does, just in a less efficient fashion. Simply redoing the implementation in terms of a plist gets rid of a lot of this junk (although there are several other strange things that could do with tidying up, like pm_qos_request_list has to carry the pm_qos_class with every node, simply because it doesn't get passed in to pm_qos_update_request even though every caller knows full well what parameter it's updating). I think this redo is a win independent of android, so we should do something like this now. Signed-off-by: James Bottomley <James.Bottomley@suse.de> Signed-off-by: mark gross <markgross@thegnar.org> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-07-19PM: Make it possible to avoid races between wakeup and system sleepRafael J. Wysocki3-7/+72
One of the arguments during the suspend blockers discussion was that the mainline kernel didn't contain any mechanisms making it possible to avoid races between wakeup and system suspend. Generally, there are two problems in that area. First, if a wakeup event occurs exactly when /sys/power/state is being written to, it may be delivered to user space right before the freezer kicks in, so the user space consumer of the event may not be able to process it before the system is suspended. Second, if a wakeup event occurs after user space has been frozen, it is not generally guaranteed that the ongoing transition of the system into a sleep state will be aborted. To address these issues introduce a new global sysfs attribute, /sys/power/wakeup_count, associated with a running counter of wakeup events and three helper functions, pm_stay_awake(), pm_relax(), and pm_wakeup_event(), that may be used by kernel subsystems to control the behavior of this attribute and to request the PM core to abort system transitions into a sleep state already in progress. The /sys/power/wakeup_count file may be read from or written to by user space. Reads will always succeed (unless interrupted by a signal) and return the current value of the wakeup events counter. Writes, however, will only succeed if the written number is equal to the current value of the wakeup events counter. If a write is successful, it will cause the kernel to save the current value of the wakeup events counter and to abort the subsequent system transition into a sleep state if any wakeup events are reported after the write has returned. [The assumption is that before writing to /sys/power/state user space will first read from /sys/power/wakeup_count. Next, user space consumers of wakeup events will have a chance to acknowledge or veto the upcoming system transition to a sleep state. Finally, if the transition is allowed to proceed, /sys/power/wakeup_count will be written to and if that succeeds, /sys/power/state will be written to as well. Still, if any wakeup events are reported to the PM core by kernel subsystems after that point, the transition will be aborted.] Additionally, put a wakeup events counter into struct dev_pm_info and make these per-device wakeup event counters available via sysfs, so that it's possible to check the activity of various wakeup event sources within the kernel. To illustrate how subsystems can use pm_wakeup_event(), make the low-level PCI runtime PM wakeup-handling code use it. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Acked-by: markgross <markgross@thegnar.org> Reviewed-by: Alan Stern <stern@rowland.harvard.edu>
2010-07-19PM / Hibernate: Fix typos in comments in kernel/power/swap.cCesar Eduardo Barros1-2/+2
There are a few typos in kernel/power/swap.c. Fix them. Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.net> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-07-05module: initialize module dynamic debug laterYehuda Sadeh1-8/+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>
2010-07-02Merge branch 'sched-fixes-for-linus' of ↵Linus Torvalds2-10/+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
2010-07-01sched: Cure nr_iowait_cpu() usersPeter Zijlstra2-10/+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>
2010-07-01futex: futex_find_get_task remove credentails checkMichal Hocko1-13/+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>
2010-06-30kexec: fix Oops in crash_shrink_memory()Pavan Naregundi1-3/+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>
2010-06-28Merge branch 'perf-fixes-for-linus' of ↵Linus Torvalds1-1/+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
2010-06-28Merge branch 'irq-fixes-for-linus' of ↵Linus Torvalds1-0/+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
2010-06-28Merge branch 'sched-fixes-for-linus' of ↵Linus Torvalds1-59/+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
2010-06-28Merge branch 'timers-fixes-for-linus' of ↵Linus Torvalds1-4/+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
2010-06-28Merge branch 'core-fixes-for-linus' of ↵Linus Torvalds2-0/+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()
2010-06-25sched: Prevent compiler from optimising the sched_avg_update() loopWill Deacon1-0/+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>
2010-06-24sched: silence PROVE_RCU in sched_fork()Peter Zijlstra1-0/+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>
2010-06-23rcu: apply RCU protection to wake_affine()Daniel J Blueman1-0/+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>
2010-06-18sched: Fix over-scheduling bugAlex,Shi1-3/+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>
2010-06-17nohz: Fix nohz ratelimitPeter Zijlstra1-4/+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>
2010-06-17user_ns: Introduce user_nsmap_uid and user_ns_map_gid.Eric W. Biederman1-0/+44
Define what happens when a we view a uid from one user_namespace in another user_namepece. - If the user namespaces are the same no mapping is necessary. - For most cases of difference use overflowuid and overflowgid, the uid and gid currently used for 16bit apis when we have a 32bit uid that does fit in 16bits. Effectively the situation is the same, we want to return a uid or gid that is not assigned to any user. - For the case when we happen to be mapping the uid or gid of the creator of the target user namespace use uid 0 and gid as confusing that user with root is not a problem. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: Serge E. Hallyn <serue@us.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-12Merge branch 'bugzilla-13931-sleep-nvs' into releaseLen Brown4-17/+24
Conflicts: drivers/acpi/sleep.c Signed-off-by: Len Brown <len.brown@intel.com>
2010-06-11perf/tracing: Fix regression of perf losing kprobe eventsSteven Rostedt1-1/+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>
2010-06-10Merge branch 'perf-fixes-for-linus' of ↵Linus Torvalds1-1/+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
2010-06-10suspend: Move NVS save/restore code to generic suspend functionalityMatthew Garrett4-17/+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>
2010-06-09genirq: Deal with desc->set_type() changing desc->chipThomas Gleixner1-0/+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
2010-06-08sched: Fix PROVE_RCU vs cpu_cgroupPeter Zijlstra1-56/+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>
2010-06-08perf: Fix signed comparison in perf_adjust_period()Peter Zijlstra1-1/+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>
2010-06-05Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linusLinus Torvalds2-121/+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
2010-06-05module: fix bne2 "gave up waiting for init of module libcrc32c"Rusty Russell1-32/+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>
2010-06-05module: verify_export_symbols under the lockRusty Russell1-16/+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>
2010-06-05module: move find_module check to endLinus Torvalds1-5/+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>
2010-06-05module: make locking more fine-grained.Rusty Russell1-23/+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>
2010-06-05module: Make module sysfs functions private.Rusty Russell1-4/+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>