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2011-04-14exec: copy-and-paste the fixes into compat_do_execve() pathsOleg Nesterov
commit 114279be2120a916e8a04feeb2ac976a10016f2f upstream. Note: this patch targets 2.6.37 and tries to be as simple as possible. That is why it adds more copy-and-paste horror into fs/compat.c and uglifies fs/exec.c, this will be cleanuped later. compat_copy_strings() plays with bprm->vma/mm directly and thus has two problems: it lacks the RLIMIT_STACK check and argv/envp memory is not visible to oom killer. Export acct_arg_size() and get_arg_page(), change compat_copy_strings() to use get_arg_page(), change compat_do_execve() to do acct_arg_size(0) as do_execve() does. Add the fatal_signal_pending/cond_resched checks into compat_count() and compat_copy_strings(), this matches the code in fs/exec.c and certainly makes sense. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Andi Kleen <ak@linux.intel.com> Cc: Moritz Muehlenhoff <jmm@debian.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-14exec: make argv/envp memory visible to oom-killerOleg Nesterov
commit 3c77f845722158206a7209c45ccddc264d19319c upstream. Brad Spengler published a local memory-allocation DoS that evades the OOM-killer (though not the virtual memory RLIMIT): http://www.grsecurity.net/~spender/64bit_dos.c execve()->copy_strings() can allocate a lot of memory, but this is not visible to oom-killer, nobody can see the nascent bprm->mm and take it into account. With this patch get_arg_page() increments current's MM_ANONPAGES counter every time we allocate the new page for argv/envp. When do_execve() succeds or fails, we change this counter back. Technically this is not 100% correct, we can't know if the new page is swapped out and turn MM_ANONPAGES into MM_SWAPENTS, but I don't think this really matters and everything becomes correct once exec changes ->mm or fails. Reported-by: Brad Spengler <spender@grsecurity.net> Reviewed-and-discussed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Moritz Muehlenhoff <jmm@debian.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-14ASoC: Explicitly say registerless widgets have no registerMark Brown
commit 0ca03cd7d0fa3bfbd56958136a10f19733c4ce12 upstream. This stops code that handles widgets generically from attempting to access registers for these widgets. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Acked-by: Liam Girdwood <lrg@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-14ses: Avoid kernel panic when lun 0 is not mappedKrishnasamy, Somasundaram
commit d1e12de804f9d8ad114786ca7c2ce593cba79891 upstream. During device discovery, scsi mid layer sends INQUIRY command to LUN 0. If the LUN 0 is not mapped to host, it creates a temporary scsi_device with LUN id 0 and sends REPORT_LUNS command to it. After the REPORT_LUNS succeeds, it walks through the LUN table and adds each LUN found to sysfs. At the end of REPORT_LUNS lun table scan, it will delete the temporary scsi_device of LUN 0. When scsi devices are added to sysfs, it calls add_dev function of all the registered class interfaces. If ses driver has been registered, ses_intf_add() of ses module will be called. This function calls scsi_device_enclosure() to check the inquiry data for EncServ bit. Since inquiry was not allocated for temporary LUN 0 scsi_device, it will cause NULL pointer exception. To fix the problem, sdev->inquiry is checked for NULL before reading it. Signed-off-by: Somasundaram Krishnasamy <Somasundaram.Krishnasamy@lsi.com> Signed-off-by: Babu Moger <babu.moger@lsi.com> Signed-off-by: James Bottomley <James.Bottomley@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-03-23ftrace: Fix memory leak with function graph and cpu hotplugSteven Rostedt
commit 868baf07b1a259f5f3803c1dc2777b6c358f83cf upstream. When the fuction graph tracer starts, it needs to make a special stack for each task to save the real return values of the tasks. All running tasks have this stack created, as well as any new tasks. On CPU hot plug, the new idle task will allocate a stack as well when init_idle() is called. The problem is that cpu hotplug does not create a new idle_task. Instead it uses the idle task that existed when the cpu went down. ftrace_graph_init_task() will add a new ret_stack to the task that is given to it. Because a clone will make the task have a stack of its parent it does not check if the task's ret_stack is already NULL or not. When the CPU hotplug code starts a CPU up again, it will allocate a new stack even though one already existed for it. The solution is to treat the idle_task specially. In fact, the function_graph code already does, just not at init_idle(). Instead of using the ftrace_graph_init_task() for the idle task, which that function expects the task to be a clone, have a separate ftrace_graph_init_idle_task(). Also, we will create a per_cpu ret_stack that is used by the idle task. When we call ftrace_graph_init_idle_task() it will check if the idle task's ret_stack is NULL, if it is, then it will assign it the per_cpu ret_stack. Reported-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Suggested-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-03-14net: don't allow CAP_NET_ADMIN to load non-netdev kernel modulesVasiliy Kulikov
commit 8909c9ad8ff03611c9c96c9a92656213e4bb495b upstream. Since a8f80e8ff94ecba629542d9b4b5f5a8ee3eb565c any process with CAP_NET_ADMIN may load any module from /lib/modules/. This doesn't mean that CAP_NET_ADMIN is a superset of CAP_SYS_MODULE as modules are limited to /lib/modules/**. However, CAP_NET_ADMIN capability shouldn't allow anybody load any module not related to networking. This patch restricts an ability of autoloading modules to netdev modules with explicit aliases. This fixes CVE-2011-1019. Arnd Bergmann suggested to leave untouched the old pre-v2.6.32 behavior of loading netdev modules by name (without any prefix) for processes with CAP_SYS_MODULE to maintain the compatibility with network scripts that use autoloading netdev modules by aliases like "eth0", "wlan0". Currently there are only three users of the feature in the upstream kernel: ipip, ip_gre and sit. root@albatros:~# capsh --drop=$(seq -s, 0 11),$(seq -s, 13 34) -- root@albatros:~# grep Cap /proc/$$/status CapInh: 0000000000000000 CapPrm: fffffff800001000 CapEff: fffffff800001000 CapBnd: fffffff800001000 root@albatros:~# modprobe xfs FATAL: Error inserting xfs (/lib/modules/2.6.38-rc6-00001-g2bf4ca3/kernel/fs/xfs/xfs.ko): Operation not permitted root@albatros:~# lsmod | grep xfs root@albatros:~# ifconfig xfs xfs: error fetching interface information: Device not found root@albatros:~# lsmod | grep xfs root@albatros:~# lsmod | grep sit root@albatros:~# ifconfig sit sit: error fetching interface information: Device not found root@albatros:~# lsmod | grep sit root@albatros:~# ifconfig sit0 sit0 Link encap:IPv6-in-IPv4 NOARP MTU:1480 Metric:1 root@albatros:~# lsmod | grep sit sit 10457 0 tunnel4 2957 1 sit For CAP_SYS_MODULE module loading is still relaxed: root@albatros:~# grep Cap /proc/$$/status CapInh: 0000000000000000 CapPrm: ffffffffffffffff CapEff: ffffffffffffffff CapBnd: ffffffffffffffff root@albatros:~# ifconfig xfs xfs: error fetching interface information: Device not found root@albatros:~# lsmod | grep xfs xfs 745319 0 Reference: https://lkml.org/lkml/2011/2/24/203 Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: Michael Tokarev <mjt@tls.msk.ru> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Kees Cook <kees.cook@canonical.com> Signed-off-by: James Morris <jmorris@namei.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-03-14RxRPC: Fix v1 keysAnton Blanchard
commit f009918a1c1bbf8607b8aab3959876913a30193a upstream. commit 339412841d7 (RxRPC: Allow key payloads to be passed in XDR form) broke klog for me. I notice the v1 key struct had a kif_version field added: -struct rxkad_key { - u16 security_index; /* RxRPC header security index */ - u16 ticket_len; /* length of ticket[] */ - u32 expiry; /* time at which expires */ - u32 kvno; /* key version number */ - u8 session_key[8]; /* DES session key */ - u8 ticket[0]; /* the encrypted ticket */ -}; +struct rxrpc_key_data_v1 { + u32 kif_version; /* 1 */ + u16 security_index; + u16 ticket_length; + u32 expiry; /* time_t */ + u32 kvno; + u8 session_key[8]; + u8 ticket[0]; +}; However the code in rxrpc_instantiate strips it away: data += sizeof(kver); datalen -= sizeof(kver); Removing kif_version fixes my problem. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-03-07sctp: Fix oops when sending queued ASCONF chunksVlad Yasevich
commit c0786693404cffd80ca3cb6e75ee7b35186b2825 upstream. When we finish processing ASCONF_ACK chunk, we try to send the next queued ASCONF. This action runs the sctp state machine recursively and it's not prepared to do so. kernel BUG at kernel/timer.c:790! invalid opcode: 0000 [#1] SMP last sysfs file: /sys/module/ipv6/initstate Modules linked in: sha256_generic sctp libcrc32c ipv6 dm_multipath uinput 8139too i2c_piix4 8139cp mii i2c_core pcspkr virtio_net joydev floppy virtio_blk virtio_pci [last unloaded: scsi_wait_scan] Pid: 0, comm: swapper Not tainted 2.6.34-rc4 #15 /Bochs EIP: 0060:[<c044a2ef>] EFLAGS: 00010286 CPU: 0 EIP is at add_timer+0xd/0x1b EAX: cecbab14 EBX: 000000f0 ECX: c0957b1c EDX: 03595cf4 ESI: cecba800 EDI: cf276f00 EBP: c0957aa0 ESP: c0957aa0 DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 Process swapper (pid: 0, ti=c0956000 task=c0988ba0 task.ti=c0956000) Stack: c0957ae0 d1851214 c0ab62e4 c0ab5f26 0500ffff 00000004 00000005 00000004 <0> 00000000 d18694fd 00000004 1666b892 cecba800 cecba800 c0957b14 00000004 <0> c0957b94 d1851b11 ceda8b00 cecba800 cf276f00 00000001 c0957b14 000000d0 Call Trace: [<d1851214>] ? sctp_side_effects+0x607/0xdfc [sctp] [<d1851b11>] ? sctp_do_sm+0x108/0x159 [sctp] [<d1863386>] ? sctp_pname+0x0/0x1d [sctp] [<d1861a56>] ? sctp_primitive_ASCONF+0x36/0x3b [sctp] [<d185657c>] ? sctp_process_asconf_ack+0x2a4/0x2d3 [sctp] [<d184e35c>] ? sctp_sf_do_asconf_ack+0x1dd/0x2b4 [sctp] [<d1851ac1>] ? sctp_do_sm+0xb8/0x159 [sctp] [<d1863334>] ? sctp_cname+0x0/0x52 [sctp] [<d1854377>] ? sctp_assoc_bh_rcv+0xac/0xe1 [sctp] [<d1858f0f>] ? sctp_inq_push+0x2d/0x30 [sctp] [<d186329d>] ? sctp_rcv+0x797/0x82e [sctp] Tested-by: Wei Yongjun <yjwei@cn.fujitsu.com> Signed-off-by: Yuansong Qiao <ysqiao@research.ait.ie> Signed-off-by: Shuaijun Zhang <szhang@research.ait.ie> Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com> Signed-off-by: David S. Miller <davem@davemloft.net> Cc: maximilian attems <max@stro.at> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-03-07drm: fix unsigned vs signed comparison issue in modeset ctl ioctl.Dave Airlie
commit 1922756124ddd53846877416d92ba4a802bc658f upstream. This fixes CVE-2011-1013. Reported-by: Matthiew Herrb (OpenBSD X.org team) Signed-off-by: Dave Airlie <airlied@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-03-02CRED: Fix get_task_cred() and task_state() to not resurrect dead credentialsDavid Howells
commit de09a9771a5346029f4d11e4ac886be7f9bfdd75 upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-17sched: Use group weight, idle cpu metrics to fix imbalances during idleSuresh Siddha
Commit: aae6d3ddd8b90f5b2c8d79a2b914d1706d124193 upstream Currently we consider a sched domain to be well balanced when the imbalance is less than the domain's imablance_pct. As the number of cores and threads are increasing, current values of imbalance_pct (for example 25% for a NUMA domain) are not enough to detect imbalances like: a) On a WSM-EP system (two sockets, each having 6 cores and 12 logical threads), 24 cpu-hogging tasks get scheduled as 13 on one socket and 11 on another socket. Leading to an idle HT cpu. b) On a hypothetial 2 socket NHM-EX system (each socket having 8 cores and 16 logical threads), 16 cpu-hogging tasks can get scheduled as 9 on one socket and 7 on another socket. Leaving one core in a socket idle whereas in another socket we have a core having both its HT siblings busy. While this issue can be fixed by decreasing the domain's imbalance_pct (by making it a function of number of logical cpus in the domain), it can potentially cause more task migrations across sched groups in an overloaded case. Fix this by using imbalance_pct only during newly_idle and busy load balancing. And during idle load balancing, check if there is an imbalance in number of idle cpu's across the busiest and this sched_group or if the busiest group has more tasks than its weight that the idle cpu in this_group can pull. Reported-by: Nikhil Rao <ncrao@google.com> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1284760952.2676.11.camel@sbsiddha-MOBL3.sc.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-17sched, cgroup: Fixup broken cgroup movementPeter Zijlstra
Commit: b2b5ce022acf5e9f52f7b78c5579994fdde191d4 upstream Dima noticed that we fail to correct the ->vruntime of sleeping tasks when we move them between cgroups. Reported-by: Dima Zavin <dima@android.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Mike Galbraith <efault@gmx.de> LKML-Reference: <1287150604.29097.1513.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-17sched: Add IRQ_TIME_ACCOUNTING, finer accounting of irq timeVenkatesh Pallipadi
Commit: b52bfee445d315549d41eacf2fa7c156e7d153d5 upstream s390/powerpc/ia64 have support for CONFIG_VIRT_CPU_ACCOUNTING which does the fine granularity accounting of user, system, hardirq, softirq times. Adding that option on archs like x86 will be challenging however, given the state of TSC reliability on various platforms and also the overhead it will add in syscall entry exit. Instead, add a lighter variant that only does finer accounting of hardirq and softirq times, providing precise irq times (instead of timer tick based samples). This accounting is added with a new config option CONFIG_IRQ_TIME_ACCOUNTING so that there won't be any overhead for users not interested in paying the perf penalty. This accounting is based on sched_clock, with the code being generic. So, other archs may find it useful as well. This patch just adds the core logic and does not enable this logic yet. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1286237003-12406-5-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-17sched: Add a PF flag for ksoftirqd identificationVenkatesh Pallipadi
Commit: 6cdd5199daf0cb7b0fcc8dca941af08492612887 upstream To account softirq time cleanly in scheduler, we need to identify whether softirq is invoked in ksoftirqd context or softirq at hardirq tail context. Add PF_KSOFTIRQD for that purpose. As all PF flag bits are currently taken, create space by moving one of the infrequently used bits (PF_THREAD_BOUND) down in task_struct to be along with some other state fields. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1286237003-12406-4-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-17sched: Remove unused PF_ALIGNWARN flagDave Young
Commit: 637bbdc5b83615ef9f45f50399d1c7f27473c713 upstream PF_ALIGNWARN is not implemented and it is for 486 as the comment. It is not likely someone will implement this flag feature. So here remove this flag and leave the valuable 0x00000001 for future use. Signed-off-by: Dave Young <hidave.darkstar@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <20100913121903.GB22238@darkstar> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-17sched: Consolidate account_system_vtime extern declarationVenkatesh Pallipadi
Commit: e1e10a265d28273ab8c70be19d43dcbdeead6c5a upstream Just a minor cleanup patch that makes things easier to the following patches. No functionality change in this patch. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1286237003-12406-3-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-17sched: Fix softirq time accountingVenkatesh Pallipadi
Commit: 75e1056f5c57050415b64cb761a3acc35d91f013 upstream Peter Zijlstra found a bug in the way softirq time is accounted in VIRT_CPU_ACCOUNTING on this thread: http://lkml.indiana.edu/hypermail//linux/kernel/1009.2/01366.html The problem is, softirq processing uses local_bh_disable internally. There is no way, later in the flow, to differentiate between whether softirq is being processed or is it just that bh has been disabled. So, a hardirq when bh is disabled results in time being wrongly accounted as softirq. Looking at the code a bit more, the problem exists in !VIRT_CPU_ACCOUNTING as well. As account_system_time() in normal tick based accouting also uses softirq_count, which will be set even when not in softirq with bh disabled. Peter also suggested solution of using 2*SOFTIRQ_OFFSET as irq count for local_bh_{disable,enable} and using just SOFTIRQ_OFFSET while softirq processing. The patch below does that and adds API in_serving_softirq() which returns whether we are currently processing softirq or not. Also changes one of the usages of softirq_count in net/sched/cls_cgroup.c to in_serving_softirq. Looks like many usages of in_softirq really want in_serving_softirq. Those changes can be made individually on a case by case basis. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1286237003-12406-2-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-17sched: Remove USER_SCHEDDhaval Giani
Commit: 7c9414385ebfdd87cc542d4e7e3bb0dbb2d3ce25 upstream Remove the USER_SCHED feature. It has been scheduled to be removed in 2.6.34 as per http://marc.info/?l=linux-kernel&m=125728479022976&w=2 [trace from referenced thread] [1046577.884289] general protection fault: 0000 [#1] SMP [1046577.911332] last sysfs file: /sys/devices/platform/coretemp.7/temp1_input [1046577.938715] CPU 3 [1046577.965814] Modules linked in: ipt_REJECT xt_tcpudp iptable_filter ip_tables x_tables coretemp k8temp [1046577.994456] Pid: 38, comm: events/3 Not tainted 2.6.32.27intel #1 X8DT3 [1046578.023166] RIP: 0010:[] [] sched_destroy_group+0x3c/0x10d [1046578.052639] RSP: 0000:ffff88043e5abe10 EFLAGS: 00010097 [1046578.081360] RAX: ffff880139fa5540 RBX: ffff8803d18419c0 RCX: ffff8801d2f8fb78 [1046578.109903] RDX: dead000000200200 RSI: 0000000000000000 RDI: 0000000000000000 [1046578.109905] RBP: 0000000000000246 R08: 0000000000000020 R09: ffffffff816339b8 [1046578.109907] R10: 0000000004e6e5f0 R11: 0000000000000006 R12: ffffffff816339b8 [1046578.109909] R13: ffff8803d63ac4e0 R14: ffff88043e582340 R15: ffffffff8104a216 [1046578.109911] FS: 0000000000000000(0000) GS:ffff880028260000(0000) knlGS:0000000000000000 [1046578.109914] CS: 0010 DS: 0018 ES: 0018 CR0: 000000008005003b [1046578.109915] CR2: 00007f55ab220000 CR3: 00000001e5797000 CR4: 00000000000006e0 [1046578.109917] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [1046578.109919] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [1046578.109922] Process events/3 (pid: 38, threadinfo ffff88043e5aa000, task ffff88043e582340) [1046578.109923] Stack: [1046578.109924] ffff8803d63ac498 ffff8803d63ac4d8 ffff8803d63ac440 ffffffff8104a2c3 [1046578.109927] <0> ffff88043e5abef8 ffff880028276040 ffff8803d63ac4d8 ffffffff81050395 [1046578.109929] <0> ffff88043e582340 ffff88043e5826c8 ffff88043e582340 ffff88043e5abfd8 [1046578.109932] Call Trace: [1046578.109938] [] ? cleanup_user_struct+0xad/0xcc [1046578.109942] [] ? worker_thread+0x148/0x1d4 [1046578.109946] [] ? autoremove_wake_function+0x0/0x2e [1046578.109948] [] ? worker_thread+0x0/0x1d4 [1046578.109951] [] ? kthread+0x79/0x81 [1046578.109955] [] ? child_rip+0xa/0x20 [1046578.109957] [] ? kthread+0x0/0x81 [1046578.109959] [] ? child_rip+0x0/0x20 [1046578.109961] Code: 3c 00 4c 8b 25 02 98 3d 00 48 89 c5 83 cf ff eb 5c 48 8b 43 10 48 63 f7 48 8b 04 f0 48 8b 90 80 00 00 00 48 8b 48 78 48 89 51 08 <48> 89 0a 48 b9 00 02 20 00 00 00 ad de 48 89 88 80 00 00 00 48 [1046578.109975] RIP [] sched_destroy_group+0x3c/0x10d [1046578.109979] RSP [1046578.109981] ---[ end trace 5ebc2944b7872d4a ]--- Signed-off-by: Dhaval Giani <dhaval.giani@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1263990378.24844.3.camel@localhost> LKML-Reference: http://marc.info/?l=linux-kernel&m=129466345327931 Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2011-02-17drm/radeon: remove 0x4243 pci idAlex Deucher
commit 63a507800c8aca5a1891d598ae13f829346e8e39 upstream. 0x4243 is a PCI bridge, not a GPU. Fixes: https://bugs.freedesktop.org/show_bug.cgi?id=33815 Signed-off-by: Alex Deucher <alexdeucher@gmail.com> Signed-off-by: Dave Airlie <airlied@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-17ieee80211: correct IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK macroAmitkumar Karwar
commit 8d661f1e462d50bd83de87ee628aaf820ce3c66c upstream. It is defined in include/linux/ieee80211.h. As per IEEE spec. bit6 to bit15 in block ack parameter represents buffer size. So the bitmask should be 0xFFC0. Signed-off-by: Amitkumar Karwar <akarwar@marvell.com> Signed-off-by: Bing Zhao <bzhao@marvell.com> Reviewed-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: John W. Linville <linville@tuxdriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-17klist: Fix object alignment on 64-bit.David Miller
commit 795abaf1e4e188c4171e3cd3dbb11a9fcacaf505 upstream. Commit c0e69a5bbc6f ("klist.c: bit 0 in pointer can't be used as flag") intended to make sure that all klist objects were at least pointer size aligned, but used the constant "4" which only works on 32-bit. Use "sizeof(void *)" which is correct in all cases. Signed-off-by: David S. Miller <davem@davemloft.net> Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-17USB: serial: handle Data Carrier Detect changesLibor Pechacek
commit d14fc1a74e846d7851f24fc9519fe87dc12a1231 upstream. Alan's commit 335f8514f200e63d689113d29cb7253a5c282967 introduced .carrier_raised function in several drivers. That also means tty_port_block_til_ready can now suspend the process trying to open the serial port when Carrier Detect is low and put it into tty_port.open_wait queue. We need to wake up the process when Carrier Detect goes high and trigger TTY hangup when CD goes low. Some of the devices do not report modem status line changes, or at least we don't understand the status message, so for those we remove .carrier_raised again. Signed-off-by: Libor Pechacek <lpechacek@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-01-07sctp: Fix a race between ICMP protocol unreachable and connect()Vlad Yasevich
commit 50b5d6ad63821cea324a5a7a19854d4de1a0a819 upstream. ICMP protocol unreachable handling completely disregarded the fact that the user may have locked the socket. It proceeded to destroy the association, even though the user may have held the lock and had a ref on the association. This resulted in the following: Attempt to release alive inet socket f6afcc00 ========================= [ BUG: held lock freed! ] ------------------------- somenu/2672 is freeing memory f6afcc00-f6afcfff, with a lock still held there! (sk_lock-AF_INET){+.+.+.}, at: [<c122098a>] sctp_connect+0x13/0x4c 1 lock held by somenu/2672: #0: (sk_lock-AF_INET){+.+.+.}, at: [<c122098a>] sctp_connect+0x13/0x4c stack backtrace: Pid: 2672, comm: somenu Not tainted 2.6.32-telco #55 Call Trace: [<c1232266>] ? printk+0xf/0x11 [<c1038553>] debug_check_no_locks_freed+0xce/0xff [<c10620b4>] kmem_cache_free+0x21/0x66 [<c1185f25>] __sk_free+0x9d/0xab [<c1185f9c>] sk_free+0x1c/0x1e [<c1216e38>] sctp_association_put+0x32/0x89 [<c1220865>] __sctp_connect+0x36d/0x3f4 [<c122098a>] ? sctp_connect+0x13/0x4c [<c102d073>] ? autoremove_wake_function+0x0/0x33 [<c12209a8>] sctp_connect+0x31/0x4c [<c11d1e80>] inet_dgram_connect+0x4b/0x55 [<c11834fa>] sys_connect+0x54/0x71 [<c103a3a2>] ? lock_release_non_nested+0x88/0x239 [<c1054026>] ? might_fault+0x42/0x7c [<c1054026>] ? might_fault+0x42/0x7c [<c11847ab>] sys_socketcall+0x6d/0x178 [<c10da994>] ? trace_hardirqs_on_thunk+0xc/0x10 [<c1002959>] syscall_call+0x7/0xb This was because the sctp_wait_for_connect() would aqcure the socket lock and then proceed to release the last reference count on the association, thus cause the fully destruction path to finish freeing the socket. The simplest solution is to start a very short timer in case the socket is owned by user. When the timer expires, we can do some verification and be able to do the release properly. Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-01-07block: Deprecate QUEUE_FLAG_CLUSTER and use queue_limits insteadMartin K. Petersen
commit e692cb668fdd5a712c6ed2a2d6f2a36ee83997b4 upstream. When stacking devices, a request_queue is not always available. This forced us to have a no_cluster flag in the queue_limits that could be used as a carrier until the request_queue had been set up for a metadevice. There were several problems with that approach. First of all it was up to the stacking device to remember to set queue flag after stacking had completed. Also, the queue flag and the queue limits had to be kept in sync at all times. We got that wrong, which could lead to us issuing commands that went beyond the max scatterlist limit set by the driver. The proper fix is to avoid having two flags for tracking the same thing. We deprecate QUEUE_FLAG_CLUSTER and use the queue limit directly in the block layer merging functions. The queue_limit 'no_cluster' is turned into 'cluster' to avoid double negatives and to ease stacking. Clustering defaults to being enabled as before. The queue flag logic is removed from the stacking function, and explicitly setting the cluster flag is no longer necessary in DM and MD. Reported-by: Ed Lin <ed.lin@promise.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Acked-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-01-07nfsd: Fix possible BUG_ON firing in set_change_infoNeil Brown
commit c1ac3ffcd0bc7e9617f62be8c7043d53ab84deac upstream. If vfs_getattr in fill_post_wcc returns an error, we don't set fh_post_change. For NFSv4, this can result in set_change_info triggering a BUG_ON. i.e. fh_post_saved being zero isn't really a bug. So: - instead of BUGging when fh_post_saved is zero, just clear ->atomic. - if vfs_getattr fails in fill_post_wcc, take a copy of i_ctime anyway. This will be used i seg_change_info, but not overly trusted. - While we are there, remove the pointless 'if' statements in set_change_info. There is no harm setting all the values. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-12-09net: Limit socket I/O iovec total length to INT_MAX.David S. Miller
commit 8acfe468b0384e834a303f08ebc4953d72fb690a upstream. This helps protect us from overflow issues down in the individual protocol sendmsg/recvmsg handlers. Once we hit INT_MAX we truncate out the rest of the iovec by setting the iov_len members to zero. This works because: 1) For SOCK_STREAM and SOCK_SEQPACKET sockets, partial writes are allowed and the application will just continue with another write to send the rest of the data. 2) For datagram oriented sockets, where there must be a one-to-one correspondance between write() calls and packets on the wire, INT_MAX is going to be far larger than the packet size limit the protocol is going to check for and signal with -EMSGSIZE. Based upon a patch by Linus Torvalds. Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-12-09x25: Patch to fix bug 15678 - x25 accesses fields beyond end of packet.John Hughes
commit f5eb917b861828da18dc28854308068c66d1449a upstream. Here is a patch to stop X.25 examining fields beyond the end of the packet. For example, when a simple CALL ACCEPTED was received: 10 10 0f x25_parse_facilities was attempting to decode the FACILITIES field, but this packet contains no facilities field. Signed-off-by: John Hughes <john@calva.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-12-09ssb: b43-pci-bridge: Add new vendor for BCM4318Daniel Klaffenbach
commit 1d8638d4038eb8709edc80e37a0bbb77253d86e9 upstream. Add new vendor for Broadcom 4318. Signed-off-by: Daniel Klaffenbach <danielklaffenbach@gmail.com> Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net> Signed-off-by: John W. Linville <linville@tuxdriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-12-09ahci,ata_generic: let ata_generic handle new MBP w/ MCP89Tejun Heo
commit c6353b4520788e34098bbf61c73fb9618ca7fdd6 upstream. For yet unknown reason, MCP89 on MBP 7,1 doesn't work w/ ahci under linux but the controller doesn't require explicit mode setting and works fine with ata_generic. Make ahci ignore the controller on MBP 7,1 and let ata_generic take it for now. Reported in bko#15923. https://bugzilla.kernel.org/show_bug.cgi?id=15923 NVIDIA is investigating why ahci mode doesn't work. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Peer Chen <pchen@nvidia.com> Reported-by: Anders Østhus <grapz666@gmail.com> Reported-by: Andreas Graf <andreas_graf@csgraf.de> Reported-by: Benoit Gschwind <gschwind@gnu-log.net> Reported-by: Damien Cassou <damien.cassou@gmail.com> Reported-by: tixetsal@juno.com Signed-off-by: Jeff Garzik <jgarzik@redhat.com> Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-12-09block: Ensure physical block size is unsigned intMartin K. Petersen
commit 892b6f90db81cccb723d5d92f4fddc2d68b206e1 upstream. Physical block size was declared unsigned int to accomodate the maximum size reported by READ CAPACITY(16). Make sure we use the right type in the related functions. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Acked-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-10-28mm: Move vma_stack_continue into mm.hStefan Bader
commit 39aa3cb3e8250db9188a6f1e3fb62ffa1a717678 upstream. So it can be used by all that need to check for that. Signed-off-by: Stefan Bader <stefan.bader@canonical.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-10-28tcp: Fix >4GB writes on 64-bit.David S. Miller
[ Upstream commit 01db403cf99f739f86903314a489fb420e0e254f ] Fixes kernel bugzilla #16603 tcp_sendmsg() truncates iov_len to an 'int' which a 4GB write to write zero bytes, for example. There is also the problem higher up of how verify_iovec() works. It wants to prevent the total length from looking like an error return value. However it does this using 'int', but syscalls return 'long' (and thus signed 64-bit on 64-bit machines). So it could trigger false-positives on 64-bit as written. So fix it to use 'long'. Reported-by: Olaf Bonorden <bono@onlinehome.de> Reported-by: Daniel Büse <dbuese@gmx.de> Reported-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-10-28drm/radeon: fix PCI ID 5657 to be an RV410Dave Airlie
commit f459ffbdfd04edb4a8ce6eea33170eb057a5e695 upstream. fixes https://bugzilla.kernel.org/show_bug.cgi?id=19012 Signed-off-by: Dave Airlie <airlied@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-10-28x86/amd-iommu: Work around S3 BIOS bugJoerg Roedel
commit 4c894f47bb49284008073d351c0ddaac8860864e upstream. This patch adds a workaround for an IOMMU BIOS problem to the AMD IOMMU driver. The result of the bug is that the IOMMU does not execute commands anymore when the system comes out of the S3 state resulting in system failure. The bug in the BIOS is that is does not restore certain hardware specific registers correctly. This workaround reads out the contents of these registers at boot time and restores them on resume from S3. The workaround is limited to the specific IOMMU chipset where this problem occurs. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-09-26guard page for stacks that grow upwardsLuck, Tony
commit 8ca3eb08097f6839b2206e2242db4179aee3cfb3 upstream. pa-risc and ia64 have stacks that grow upwards. Check that they do not run into other mappings. By making VM_GROWSUP 0x0 on architectures that do not ever use it, we can avoid some unpleasant #ifdefs in check_stack_guard_page(). Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: dann frazier <dannf@debian.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-09-26mm: page allocator: calculate a better estimate of NR_FREE_PAGES when memory ↵Christoph Lameter
is low and kswapd is awake commit aa45484031ddee09b06350ab8528bfe5b2c76d1c upstream. Ordinarily watermark checks are based on the vmstat NR_FREE_PAGES as it is cheaper than scanning a number of lists. To avoid synchronization overhead, counter deltas are maintained on a per-cpu basis and drained both periodically and when the delta is above a threshold. On large CPU systems, the difference between the estimated and real value of NR_FREE_PAGES can be very high. If NR_FREE_PAGES is much higher than number of real free page in buddy, the VM can allocate pages below min watermark, at worst reducing the real number of pages to zero. Even if the OOM killer kills some victim for freeing memory, it may not free memory if the exit path requires a new page resulting in livelock. This patch introduces a zone_page_state_snapshot() function (courtesy of Christoph) that takes a slightly more accurate view of an arbitrary vmstat counter. It is used to read NR_FREE_PAGES while kswapd is awake to avoid the watermark being accidentally broken. The estimate is not perfect and may result in cache line bounces but is expected to be lighter than the IPI calls necessary to continually drain the per-cpu counters while kswapd is awake. Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-09-26tcp: Prevent overzealous packetization by SWS logic.Alexey Kuznetsov
[ Upstream commit 01f83d69844d307be2aa6fea88b0e8fe5cbdb2f4 ] If peer uses tiny MSS (say, 75 bytes) and similarly tiny advertised window, the SWS logic will packetize to half the MSS unnecessarily. This causes problems with some embedded devices. However for large MSS devices we do want to half-MSS packetize otherwise we never get enough packets into the pipe for things like fast retransmit and recovery to work. Be careful also to handle the case where MSS > window, otherwise we'll never send until the probe timer. Reported-by: ツ Leandro Melo de Sales <leandroal@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-09-26tcp: Combat per-cpu skew in orphan tests.David S. Miller
[ Upstream commit ad1af0fedba14f82b240a03fe20eb9b2fdbd0357 ] As reported by Anton Blanchard when we use percpu_counter_read_positive() to make our orphan socket limit checks, the check can be off by up to num_cpus_online() * batch (which is 32 by default) which on a 128 cpu machine can be as large as the default orphan limit itself. Fix this by doing the full expensive sum check if the optimized check triggers. Reported-by: Anton Blanchard <anton@samba.org> Signed-off-by: David S. Miller <davem@davemloft.net> Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-09-20sched: Pre-compute cpumask_weight(sched_domain_span(sd))Peter Zijlstra
commit 669c55e9f99b90e46eaa0f98a67ec53d46dc969a upstream Dave reported that his large SPARC machines spend lots of time in hweight64(), try and optimize some of those needless cpumask_weight() invocations (esp. with the large offstack cpumasks these are very expensive indeed). Reported-by: David Miller <davem@davemloft.net> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-09-20sched: Fix vmark regression on big machinesMike Galbraith
commit 50b926e439620c469565e8be0f28be78f5fca1ce upstream SD_PREFER_SIBLING is set at the CPU domain level if power saving isn't enabled, leading to many cache misses on large machines as we traverse looking for an idle shared cache to wake to. Change the enabler of select_idle_sibling() to SD_SHARE_PKG_RESOURCES, and enable same at the sibling domain level. Reported-by: Lin Ming <ming.m.lin@intel.com> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1262612696.15495.15.camel@marge.simson.net> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-09-20sched: Fix TASK_WAKING vs fork deadlockPeter Zijlstra
commit 0017d735092844118bef006696a750a0e4ef6ebd upstream Oleg noticed a few races with the TASK_WAKING usage on fork. - since TASK_WAKING is basically a spinlock, it should be IRQ safe - since we set TASK_WAKING (*) without holding rq->lock it could be there still is a rq->lock holder, thereby not actually providing full serialization. (*) in fact we clear PF_STARTING, which in effect enables TASK_WAKING. Cure the second issue by not setting TASK_WAKING in sched_fork(), but only temporarily in wake_up_new_task() while calling select_task_rq(). Cure the first by holding rq->lock around the select_task_rq() call, this will disable IRQs, this however requires that we push down the rq->lock release into select_task_rq_fair()'s cgroup stuff. Because select_task_rq_fair() still needs to drop the rq->lock we cannot fully get rid of TASK_WAKING. Reported-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-09-20sched: Make select_fallback_rq() cpuset friendlyOleg Nesterov
commit 9084bb8246ea935b98320554229e2f371f7f52fa upstream Introduce cpuset_cpus_allowed_fallback() helper to fix the cpuset problems with select_fallback_rq(). It can be called from any context and can't use any cpuset locks including task_lock(). It is called when the task doesn't have online cpus in ->cpus_allowed but ttwu/etc must be able to find a suitable cpu. I am not proud of this patch. Everything which needs such a fat comment can't be good even if correct. But I'd prefer to not change the locking rules in the code I hardly understand, and in any case I believe this simple change make the code much more correct compared to deadlocks we currently have. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20100315091027.GA9155@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-09-20sched: _cpu_down(): Don't play with current->cpus_allowedOleg Nesterov
commit 6a1bdc1b577ebcb65f6603c57f8347309bc4ab13 upstream _cpu_down() changes the current task's affinity and then recovers it at the end. The problems are well known: we can't restore old_allowed if it was bound to the now-dead-cpu, and we can race with the userspace which can change cpu-affinity during unplug. _cpu_down() should not play with current->cpus_allowed at all. Instead, take_cpu_down() can migrate the caller of _cpu_down() after __cpu_disable() removes the dying cpu from cpu_online_mask. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20100315091023.GA9148@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-09-20sched: Kill the broken and deadlockable ↵Oleg Nesterov
cpuset_lock/cpuset_cpus_allowed_locked code commit 897f0b3c3ff40b443c84e271bef19bd6ae885195 upstream This patch just states the fact the cpusets/cpuhotplug interaction is broken and removes the deadlockable code which only pretends to work. - cpuset_lock() doesn't really work. It is needed for cpuset_cpus_allowed_locked() but we can't take this lock in try_to_wake_up()->select_fallback_rq() path. - cpuset_lock() is deadlockable. Suppose that a task T bound to CPU takes callback_mutex. If cpu_down(CPU) happens before T drops callback_mutex stop_machine() preempts T, then migration_call(CPU_DEAD) tries to take cpuset_lock() and hangs forever because CPU is already dead and thus T can't be scheduled. - cpuset_cpus_allowed_locked() is deadlockable too. It takes task_lock() which is not irq-safe, but try_to_wake_up() can be called from irq. Kill them, and change select_fallback_rq() to use cpu_possible_mask, like we currently do without CONFIG_CPUSETS. Also, with or without this patch, with or without CONFIG_CPUSETS, the callers of select_fallback_rq() can race with each other or with set_cpus_allowed() pathes. The subsequent patches try to to fix these problems. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20100315091003.GA9123@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-09-20sched: Extend enqueue_task to allow head queueingThomas Gleixner
commit ea87bb7853168434f4a82426dd1ea8421f9e604d upstream The ability of enqueueing a task to the head of a SCHED_FIFO priority list is required to fix some violations of POSIX scheduling policy. Extend the related functions with a "head" argument. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Tested-by: Carsten Emde <cbe@osadl.org> Tested-by: Mathias Weber <mathias.weber.mw1@roche.com> LKML-Reference: <20100120171629.734886007@linutronix.de> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-09-20sched: Remove the cfs_rq dependency from set_task_cpu()Peter Zijlstra
commit 88ec22d3edb72b261f8628226cd543589a6d5e1b upstream In order to remove the cfs_rq dependency from set_task_cpu() we need to ensure the task is cfs_rq invariant for all callsites. The simple approach is to substract cfs_rq->min_vruntime from se->vruntime on dequeue, and add cfs_rq->min_vruntime on enqueue. However, this has the downside of breaking FAIR_SLEEPERS since we loose the old vruntime as we only maintain the relative position. To solve this, we observe that we only migrate runnable tasks, we do this using deactivate_task(.sleep=0) and activate_task(.wakeup=0), therefore we can restrain the min_vruntime invariance to that state. The only other case is wakeup balancing, since we want to maintain the old vruntime we cannot make it relative on dequeue, but since we don't migrate inactive tasks, we can do so right before we activate it again. This is where we need the new pre-wakeup hook, we need to call this while still holding the old rq->lock. We could fold it into ->select_task_rq(), but since that has multiple callsites and would obfuscate the locking requirements, that seems like a fudge. This leaves the fork() case, simply make sure that ->task_fork() leaves the ->vruntime in a relative state. This covers all cases where set_task_cpu() gets called, and ensures it sees a relative vruntime. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <20091216170518.191697025@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-09-20sched: Add pre and post wakeup hooksPeter Zijlstra
commit efbbd05a595343a413964ad85a2ad359b7b7efbd upstream As will be apparent in the next patch, we need a pre wakeup hook for sched_fair task migration, hence rename the post wakeup hook and one pre wakeup. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <20091216170518.114746117@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-09-20sched: Remove forced2_migrations statsIngo Molnar
commit b9889ed1ddeca5a3f3569c8de7354e9e97d803ae upstream This build warning: kernel/sched.c: In function 'set_task_cpu': kernel/sched.c:2070: warning: unused variable 'old_rq' Made me realize that the forced2_migrations stat looks pretty pointless (and a misnomer) - remove it. Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-09-20sched: Sanitize fork() handlingPeter Zijlstra
commit cd29fe6f2637cc2ccbda5ac65f5332d6bf5fa3c6 upstream Currently we try to do task placement in wake_up_new_task() after we do the load-balance pass in sched_fork(). This yields complicated semantics in that we have to deal with tasks on different RQs and the set_task_cpu() calls in copy_process() and sched_fork() Rename ->task_new() to ->task_fork() and call it from sched_fork() before the balancing, this gives the policy a clear point to place the task. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-09-20sched: Remove unused cpu_nr_migrations()Hiroshi Shimamoto
commit 9824a2b728b63e7ff586b9fd9293c819be79f0f3 upstream cpu_nr_migrations() is not used, remove it. Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <4AF12A66.6020609@ct.jp.nec.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>