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2013-11-05tracing: Make register/unregister_ftrace_command __initTom Zanussi
register/unregister_ftrace_command() are only ever called from __init functions, so can themselves be made __init. Also make register_snapshot_cmd() __init for the same reason. Link: http://lkml.kernel.org/r/d4042c8cadb7ae6f843ac9a89a24e1c6a3099727.1382620672.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-11-05tracing: Update event filters for multibufferTom Zanussi
The trace event filters are still tied to event calls rather than event files, which means you don't get what you'd expect when using filters in the multibuffer case: Before: # echo 'bytes_alloc > 8192' > /sys/kernel/debug/tracing/events/kmem/kmalloc/filter # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/filter bytes_alloc > 8192 # mkdir /sys/kernel/debug/tracing/instances/test1 # echo 'bytes_alloc > 2048' > /sys/kernel/debug/tracing/instances/test1/events/kmem/kmalloc/filter # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/filter bytes_alloc > 2048 # cat /sys/kernel/debug/tracing/instances/test1/events/kmem/kmalloc/filter bytes_alloc > 2048 Setting the filter in tracing/instances/test1/events shouldn't affect the same event in tracing/events as it does above. After: # echo 'bytes_alloc > 8192' > /sys/kernel/debug/tracing/events/kmem/kmalloc/filter # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/filter bytes_alloc > 8192 # mkdir /sys/kernel/debug/tracing/instances/test1 # echo 'bytes_alloc > 2048' > /sys/kernel/debug/tracing/instances/test1/events/kmem/kmalloc/filter # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/filter bytes_alloc > 8192 # cat /sys/kernel/debug/tracing/instances/test1/events/kmem/kmalloc/filter bytes_alloc > 2048 We'd like to just move the filter directly from ftrace_event_call to ftrace_event_file, but there are a couple cases that don't yet have multibuffer support and therefore have to continue using the current event_call-based filters. For those cases, a new USE_CALL_FILTER bit is added to the event_call flags, whose main purpose is to keep the old behavior for those cases until they can be updated with multibuffer support; at that point, the USE_CALL_FILTER flag (and the new associated call_filter_check_discard() function) can go away. The multibuffer support also made filter_current_check_discard() redundant, so this change removes that function as well and replaces it with filter_check_discard() (or call_filter_check_discard() as appropriate). Link: http://lkml.kernel.org/r/f16e9ce4270c62f46b2e966119225e1c3cca7e60.1382620672.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-11-05ftrace: Have control op function callback only trace when RCU is watchingSteven Rostedt (Red Hat)
Dave Jones reported that trinity would be able to trigger the following back trace: =============================== [ INFO: suspicious RCU usage. ] 3.10.0-rc2+ #38 Not tainted ------------------------------- include/linux/rcupdate.h:771 rcu_read_lock() used illegally while idle! other info that might help us debug this: RCU used illegally from idle CPU! rcu_scheduler_active = 1, debug_locks = 0 RCU used illegally from extended quiescent state! 1 lock held by trinity-child1/18786: #0: (rcu_read_lock){.+.+..}, at: [<ffffffff8113dd48>] __perf_event_overflow+0x108/0x310 stack backtrace: CPU: 3 PID: 18786 Comm: trinity-child1 Not tainted 3.10.0-rc2+ #38 0000000000000000 ffff88020767bac8 ffffffff816e2f6b ffff88020767baf8 ffffffff810b5897 ffff88021de92520 0000000000000000 ffff88020767bbf8 0000000000000000 ffff88020767bb78 ffffffff8113ded4 ffffffff8113dd48 Call Trace: [<ffffffff816e2f6b>] dump_stack+0x19/0x1b [<ffffffff810b5897>] lockdep_rcu_suspicious+0xe7/0x120 [<ffffffff8113ded4>] __perf_event_overflow+0x294/0x310 [<ffffffff8113dd48>] ? __perf_event_overflow+0x108/0x310 [<ffffffff81309289>] ? __const_udelay+0x29/0x30 [<ffffffff81076054>] ? __rcu_read_unlock+0x54/0xa0 [<ffffffff816f4000>] ? ftrace_call+0x5/0x2f [<ffffffff8113dfa1>] perf_swevent_overflow+0x51/0xe0 [<ffffffff8113e08f>] perf_swevent_event+0x5f/0x90 [<ffffffff8113e1c9>] perf_tp_event+0x109/0x4f0 [<ffffffff8113e36f>] ? perf_tp_event+0x2af/0x4f0 [<ffffffff81074630>] ? __rcu_read_lock+0x20/0x20 [<ffffffff8112d79f>] perf_ftrace_function_call+0xbf/0xd0 [<ffffffff8110e1e1>] ? ftrace_ops_control_func+0x181/0x210 [<ffffffff81074630>] ? __rcu_read_lock+0x20/0x20 [<ffffffff81100cae>] ? rcu_eqs_enter_common+0x5e/0x470 [<ffffffff8110e1e1>] ftrace_ops_control_func+0x181/0x210 [<ffffffff816f4000>] ftrace_call+0x5/0x2f [<ffffffff8110e229>] ? ftrace_ops_control_func+0x1c9/0x210 [<ffffffff816f4000>] ? ftrace_call+0x5/0x2f [<ffffffff81074635>] ? debug_lockdep_rcu_enabled+0x5/0x40 [<ffffffff81074635>] ? debug_lockdep_rcu_enabled+0x5/0x40 [<ffffffff81100cae>] ? rcu_eqs_enter_common+0x5e/0x470 [<ffffffff8110112a>] rcu_eqs_enter+0x6a/0xb0 [<ffffffff81103673>] rcu_user_enter+0x13/0x20 [<ffffffff8114541a>] user_enter+0x6a/0xd0 [<ffffffff8100f6d8>] syscall_trace_leave+0x78/0x140 [<ffffffff816f46af>] int_check_syscall_exit_work+0x34/0x3d ------------[ cut here ]------------ Perf uses rcu_read_lock() but as the function tracer can trace functions even when RCU is not currently active, this makes the rcu_read_lock() used by perf ineffective. As perf is currently the only user of the ftrace_ops_control_func() and perf is also the only function callback that actively uses rcu_read_lock(), the quick fix is to prevent the ftrace_ops_control_func() from calling its callbacks if RCU is not active. With Paul's new "rcu_is_watching()" we can tell if RCU is active or not. Reported-by: Dave Jones <davej@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-11-05rcu: Do not trace rcu_is_watching() functionsSteven Rostedt
As perf uses the rcu_read_lock() primitives for recording into its ring buffer, perf tracing can not be called when RCU in inactive. With the perf function tracing, there are functions that can be traced when RCU is not active, and perf must not have its function callback called when this is the case. Luckily, Paul McKenney has created a way to detect when RCU is active or not with the rcu_is_watching() function. Unfortunately, this function can also be traced, and if that happens it can cause a bit of overhead for the perf function calls that do the check. Recursion protection prevents anything bad from happening, but there is a bit of added overhead for every function being traced that must detect that the rcu_is_watching() is also being traced. As rcu_is_watching() is a helper routine and not part of the critical logic in RCU, it does not need to be traced in order to debug RCU itself. Add the "notrace" annotation to all the rcu_is_watching() calls such that we never trace it. Link: http://lkml.kernel.org/r/20131104202736.72dd8e45@gandalf.local.home Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-11-05Merge branch 'idle.2013.09.25a' of ↵Steven Rostedt (Red Hat)
git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into HEAD Need to use Paul McKenney's "rcu_is_watching()" changes to fix a perf/ftrace bug.
2013-11-05trace/trace_stat: use rbtree postorder iteration helper instead of opencodingCody P Schafer
Use rbtree_postorder_for_each_entry_safe() to destroy the rbtree instead of opencoding an alternate postorder iteration that modifies the tree Link: http://lkml.kernel.org/r/1383345566-25087-2-git-send-email-cody@linux.vnet.ibm.com Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-10-18ftrace: Add set_graph_notrace filterNamhyung Kim
The set_graph_notrace filter is analogous to set_ftrace_notrace and can be used for eliminating uninteresting part of function graph trace output. It also works with set_graph_function nicely. # cd /sys/kernel/debug/tracing/ # echo do_page_fault > set_graph_function # perf ftrace live true 2) | do_page_fault() { 2) | __do_page_fault() { 2) 0.381 us | down_read_trylock(); 2) 0.055 us | __might_sleep(); 2) 0.696 us | find_vma(); 2) | handle_mm_fault() { 2) | handle_pte_fault() { 2) | __do_fault() { 2) | filemap_fault() { 2) | find_get_page() { 2) 0.033 us | __rcu_read_lock(); 2) 0.035 us | __rcu_read_unlock(); 2) 1.696 us | } 2) 0.031 us | __might_sleep(); 2) 2.831 us | } 2) | _raw_spin_lock() { 2) 0.046 us | add_preempt_count(); 2) 0.841 us | } 2) 0.033 us | page_add_file_rmap(); 2) | _raw_spin_unlock() { 2) 0.057 us | sub_preempt_count(); 2) 0.568 us | } 2) | unlock_page() { 2) 0.084 us | page_waitqueue(); 2) 0.126 us | __wake_up_bit(); 2) 1.117 us | } 2) 7.729 us | } 2) 8.397 us | } 2) 8.956 us | } 2) 0.085 us | up_read(); 2) + 12.745 us | } 2) + 13.401 us | } ... # echo handle_mm_fault > set_graph_notrace # perf ftrace live true 1) | do_page_fault() { 1) | __do_page_fault() { 1) 0.205 us | down_read_trylock(); 1) 0.041 us | __might_sleep(); 1) 0.344 us | find_vma(); 1) 0.069 us | up_read(); 1) 4.692 us | } 1) 5.311 us | } ... Link: http://lkml.kernel.org/r/1381739066-7531-5-git-send-email-namhyung@kernel.org Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-10-18ftrace: Narrow down the protected area of graph_lockNamhyung Kim
The parser set up is just a generic utility that uses local variables allocated by the function. There's no need to hold the graph_lock for this set up. This also makes the code simpler. Link: http://lkml.kernel.org/r/1381739066-7531-4-git-send-email-namhyung@kernel.org Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-10-18ftrace: Introduce struct ftrace_graph_dataNamhyung Kim
The struct ftrace_graph_data is for generalizing the access to set_graph_function file. This is a preparation for adding support to set_graph_notrace. Link: http://lkml.kernel.org/r/1381739066-7531-3-git-send-email-namhyung@kernel.org Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-10-18ftrace: Get rid of ftrace_graph_filter_enabledNamhyung Kim
The ftrace_graph_filter_enabled means that user sets function filter and it always has same meaning of ftrace_graph_count > 0. Link: http://lkml.kernel.org/r/1381739066-7531-2-git-send-email-namhyung@kernel.org Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-10-18tracing: Fix potential out-of-bounds in trace_get_user()Steven Rostedt
Andrey reported the following report: ERROR: AddressSanitizer: heap-buffer-overflow on address ffff8800359c99f3 ffff8800359c99f3 is located 0 bytes to the right of 243-byte region [ffff8800359c9900, ffff8800359c99f3) Accessed by thread T13003: #0 ffffffff810dd2da (asan_report_error+0x32a/0x440) #1 ffffffff810dc6b0 (asan_check_region+0x30/0x40) #2 ffffffff810dd4d3 (__tsan_write1+0x13/0x20) #3 ffffffff811cd19e (ftrace_regex_release+0x1be/0x260) #4 ffffffff812a1065 (__fput+0x155/0x360) #5 ffffffff812a12de (____fput+0x1e/0x30) #6 ffffffff8111708d (task_work_run+0x10d/0x140) #7 ffffffff810ea043 (do_exit+0x433/0x11f0) #8 ffffffff810eaee4 (do_group_exit+0x84/0x130) #9 ffffffff810eafb1 (SyS_exit_group+0x21/0x30) #10 ffffffff81928782 (system_call_fastpath+0x16/0x1b) Allocated by thread T5167: #0 ffffffff810dc778 (asan_slab_alloc+0x48/0xc0) #1 ffffffff8128337c (__kmalloc+0xbc/0x500) #2 ffffffff811d9d54 (trace_parser_get_init+0x34/0x90) #3 ffffffff811cd7b3 (ftrace_regex_open+0x83/0x2e0) #4 ffffffff811cda7d (ftrace_filter_open+0x2d/0x40) #5 ffffffff8129b4ff (do_dentry_open+0x32f/0x430) #6 ffffffff8129b668 (finish_open+0x68/0xa0) #7 ffffffff812b66ac (do_last+0xb8c/0x1710) #8 ffffffff812b7350 (path_openat+0x120/0xb50) #9 ffffffff812b8884 (do_filp_open+0x54/0xb0) #10 ffffffff8129d36c (do_sys_open+0x1ac/0x2c0) #11 ffffffff8129d4b7 (SyS_open+0x37/0x50) #12 ffffffff81928782 (system_call_fastpath+0x16/0x1b) Shadow bytes around the buggy address: ffff8800359c9700: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd ffff8800359c9780: fd fd fd fd fd fd fd fd fa fa fa fa fa fa fa fa ffff8800359c9800: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa ffff8800359c9880: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa ffff8800359c9900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 =>ffff8800359c9980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00[03]fb ffff8800359c9a00: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa ffff8800359c9a80: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa ffff8800359c9b00: fa fa fa fa fa fa fa fa 00 00 00 00 00 00 00 00 ffff8800359c9b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8800359c9c00: 00 00 00 00 00 00 00 00 fa fa fa fa fa fa fa fa Shadow byte legend (one shadow byte represents 8 application bytes): Addressable: 00 Partially addressable: 01 02 03 04 05 06 07 Heap redzone: fa Heap kmalloc redzone: fb Freed heap region: fd Shadow gap: fe The out-of-bounds access happens on 'parser->buffer[parser->idx] = 0;' Although the crash happened in ftrace_regex_open() the real bug occurred in trace_get_user() where there's an incrementation to parser->idx without a check against the size. The way it is triggered is if userspace sends in 128 characters (EVENT_BUF_SIZE + 1), the loop that reads the last character stores it and then breaks out because there is no more characters. Then the last character is read to determine what to do next, and the index is incremented without checking size. Then the caller of trace_get_user() usually nulls out the last character with a zero, but since the index is equal to the size, it writes a nul character after the allocated space, which can corrupt memory. Luckily, only root user has write access to this file. Link: http://lkml.kernel.org/r/20131009222323.04fd1a0d@gandalf.local.home Reported-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-10-09tracing: Show more exact help information about snapshotWang YanQing
The current "help" that comes out of the snapshot file when it is not allocated looks like this: # * Snapshot is freed * # # Snapshot commands: # echo 0 > snapshot : Clears and frees snapshot buffer # echo 1 > snapshot : Allocates snapshot buffer, if not already allocated. # Takes a snapshot of the main buffer. # echo 2 > snapshot : Clears snapshot buffer (but does not allocate) # (Doesn't have to be '2' works with any number that # is not a '0' or '1') Echo 2 says that it does not allocate the buffer, which is correct, but to be more consistent with "echo 0" it should also state that it does not free. Link: http://lkml.kernel.org/r/20130914045916.GA4243@udknight Signed-off-by: Wang YanQing <udknight@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-10-04Merge tag 'pm+acpi-3.12-rc4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull ACPI and power management fixes from Rafael Wysocki: - The resume part of user space driven hibernation (s2disk) is now broken after the change that moved the creation of memory bitmaps to after the freezing of tasks, because I forgot that the resume utility loaded the image before freezing tasks and needed the bitmaps for that. The fix adds special handling for that case. - One of recent commits changed the export of acpi_bus_get_device() to EXPORT_SYMBOL_GPL(), which was technically correct but broke existing binary modules using that function including one in particularly widespread use. Change it back to EXPORT_SYMBOL(). - The intel_pstate driver sometimes fails to disable turbo if its no_turbo sysfs attribute is set. Fix from Srinivas Pandruvada. - One of recent cpufreq fixes forgot to update a check in cpufreq-cpu0 which still (incorrectly) treats non-NULL as non-error. Fix from Philipp Zabel. - The SPEAr cpufreq driver uses a wrong variable type in one place preventing it from catching errors returned by one of the functions called by it. Fix from Sachin Kamat. * tag 'pm+acpi-3.12-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: ACPI: Use EXPORT_SYMBOL() for acpi_bus_get_device() intel_pstate: fix no_turbo cpufreq: cpufreq-cpu0: NULL is a valid regulator, part 2 cpufreq: SPEAr: Fix incorrect variable type PM / hibernate: Fix user space driven resume regression
2013-10-02Merge branch 'irq/urgent-v2' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks into irq/urgent Pull a hardirq-nesting fix from Frederic Weisbecker. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-01irq: Force hardirq exit's softirq processing on its own stackFrederic Weisbecker
The commit facd8b80c67a3cf64a467c4a2ac5fb31f2e6745b ("irq: Sanitize invoke_softirq") converted irq exit calls of do_softirq() to __do_softirq() on all architectures, assuming it was only used there for its irq disablement properties. But as a side effect, the softirqs processed in the end of the hardirq are always called on the inline current stack that is used by irq_exit() instead of the softirq stack provided by the archs that override do_softirq(). The result is mostly safe if the architecture runs irq_exit() on a separate irq stack because then softirqs are processed on that same stack that is near empty at this stage (assuming hardirq aren't nesting). Otherwise irq_exit() runs in the task stack and so does the softirq too. The interrupted call stack can be randomly deep already and the softirq can dig through it even further. To add insult to the injury, this softirq can be interrupted by a new hardirq, maximizing the chances for a stack overrun as reported in powerpc for example: do_IRQ: stack overflow: 1920 CPU: 0 PID: 1602 Comm: qemu-system-ppc Not tainted 3.10.4-300.1.fc19.ppc64p7 #1 Call Trace: [c0000000050a8740] .show_stack+0x130/0x200 (unreliable) [c0000000050a8810] .dump_stack+0x28/0x3c [c0000000050a8880] .do_IRQ+0x2b8/0x2c0 [c0000000050a8930] hardware_interrupt_common+0x154/0x180 --- Exception: 501 at .cp_start_xmit+0x3a4/0x820 [8139cp] LR = .cp_start_xmit+0x390/0x820 [8139cp] [c0000000050a8d40] .dev_hard_start_xmit+0x394/0x640 [c0000000050a8e00] .sch_direct_xmit+0x110/0x260 [c0000000050a8ea0] .dev_queue_xmit+0x260/0x630 [c0000000050a8f40] .br_dev_queue_push_xmit+0xc4/0x130 [bridge] [c0000000050a8fc0] .br_dev_xmit+0x198/0x270 [bridge] [c0000000050a9070] .dev_hard_start_xmit+0x394/0x640 [c0000000050a9130] .dev_queue_xmit+0x428/0x630 [c0000000050a91d0] .ip_finish_output+0x2a4/0x550 [c0000000050a9290] .ip_local_out+0x50/0x70 [c0000000050a9310] .ip_queue_xmit+0x148/0x420 [c0000000050a93b0] .tcp_transmit_skb+0x4e4/0xaf0 [c0000000050a94a0] .__tcp_ack_snd_check+0x7c/0xf0 [c0000000050a9520] .tcp_rcv_established+0x1e8/0x930 [c0000000050a95f0] .tcp_v4_do_rcv+0x21c/0x570 [c0000000050a96c0] .tcp_v4_rcv+0x734/0x930 [c0000000050a97a0] .ip_local_deliver_finish+0x184/0x360 [c0000000050a9840] .ip_rcv_finish+0x148/0x400 [c0000000050a98d0] .__netif_receive_skb_core+0x4f8/0xb00 [c0000000050a99d0] .netif_receive_skb+0x44/0x110 [c0000000050a9a70] .br_handle_frame_finish+0x2bc/0x3f0 [bridge] [c0000000050a9b20] .br_nf_pre_routing_finish+0x2ac/0x420 [bridge] [c0000000050a9bd0] .br_nf_pre_routing+0x4dc/0x7d0 [bridge] [c0000000050a9c70] .nf_iterate+0x114/0x130 [c0000000050a9d30] .nf_hook_slow+0xb4/0x1e0 [c0000000050a9e00] .br_handle_frame+0x290/0x330 [bridge] [c0000000050a9ea0] .__netif_receive_skb_core+0x34c/0xb00 [c0000000050a9fa0] .netif_receive_skb+0x44/0x110 [c0000000050aa040] .napi_gro_receive+0xe8/0x120 [c0000000050aa0c0] .cp_rx_poll+0x31c/0x590 [8139cp] [c0000000050aa1d0] .net_rx_action+0x1dc/0x310 [c0000000050aa2b0] .__do_softirq+0x158/0x330 [c0000000050aa3b0] .irq_exit+0xc8/0x110 [c0000000050aa430] .do_IRQ+0xdc/0x2c0 [c0000000050aa4e0] hardware_interrupt_common+0x154/0x180 --- Exception: 501 at .bad_range+0x1c/0x110 LR = .get_page_from_freelist+0x908/0xbb0 [c0000000050aa7d0] .list_del+0x18/0x50 (unreliable) [c0000000050aa850] .get_page_from_freelist+0x908/0xbb0 [c0000000050aa9e0] .__alloc_pages_nodemask+0x21c/0xae0 [c0000000050aaba0] .alloc_pages_vma+0xd0/0x210 [c0000000050aac60] .handle_pte_fault+0x814/0xb70 [c0000000050aad50] .__get_user_pages+0x1a4/0x640 [c0000000050aae60] .get_user_pages_fast+0xec/0x160 [c0000000050aaf10] .__gfn_to_pfn_memslot+0x3b0/0x430 [kvm] [c0000000050aafd0] .kvmppc_gfn_to_pfn+0x64/0x130 [kvm] [c0000000050ab070] .kvmppc_mmu_map_page+0x94/0x530 [kvm] [c0000000050ab190] .kvmppc_handle_pagefault+0x174/0x610 [kvm] [c0000000050ab270] .kvmppc_handle_exit_pr+0x464/0x9b0 [kvm] [c0000000050ab320] kvm_start_lightweight+0x1ec/0x1fc [kvm] [c0000000050ab4f0] .kvmppc_vcpu_run_pr+0x168/0x3b0 [kvm] [c0000000050ab9c0] .kvmppc_vcpu_run+0xc8/0xf0 [kvm] [c0000000050aba50] .kvm_arch_vcpu_ioctl_run+0x5c/0x1a0 [kvm] [c0000000050abae0] .kvm_vcpu_ioctl+0x478/0x730 [kvm] [c0000000050abc90] .do_vfs_ioctl+0x4ec/0x7c0 [c0000000050abd80] .SyS_ioctl+0xd4/0xf0 [c0000000050abe30] syscall_exit+0x0/0x98 Since this is a regression, this patch proposes a minimalistic and low-risk solution by blindly forcing the hardirq exit processing of softirqs on the softirq stack. This way we should reduce significantly the opportunities for task stack overflow dug by softirqs. Longer term solutions may involve extending the hardirq stack coverage to irq_exit(), etc... Reported-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: #3.9.. <stable@vger.kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@au1.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Mackerras <paulus@au1.ibm.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: James E.J. Bottomley <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: David S. Miller <davem@davemloft.net> Cc: Andrew Morton <akpm@linux-foundation.org>
2013-09-30pidns: fix free_pid() to handle the first fork failureOleg Nesterov
"case 0" in free_pid() assumes that disable_pid_allocation() should clear PIDNS_HASH_ADDING before the last pid goes away. However this doesn't happen if the first fork() fails to create the child reaper which should call disable_pid_allocation(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com> Cc: "Serge E. Hallyn" <serge@hallyn.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-30kernel/kmod.c: check for NULL in call_usermodehelper_exec()Tetsuo Handa
If /proc/sys/kernel/core_pattern contains only "|", a NULL pointer dereference happens upon core dump because argv_split("") returns argv[0] == NULL. This bug was once fixed by commit 264b83c07a84 ("usermodehelper: check subprocess_info->path != NULL") but was by error reintroduced by commit 7f57cfa4e2aa ("usermodehelper: kill the sub_info->path[0] check"). This bug seems to exist since 2.6.19 (the version which core dump to pipe was added). Depending on kernel version and config, some side effect might happen immediately after this oops (e.g. kernel panic with 2.6.32-358.18.1.el6). Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-30PM / hibernate: Fix user space driven resume regressionRafael J. Wysocki
Recent commit 8fd37a4 (PM / hibernate: Create memory bitmaps after freezing user space) broke the resume part of the user space driven hibernation (s2disk), because I forgot that the resume utility loaded the image into memory without freezing user space (it still freezes tasks after loading the image). This means that during user space driven resume we need to create the memory bitmaps at the "device open" time rather than at the "freeze tasks" time, so make that happen (that's a special case anyway, so it needs to be treated in a special way). Reported-and-tested-by: Ronald <ronald645@gmail.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-09-28Merge branches 'sched-urgent-for-linus', 'timers-urgent-for-linus' and ↵Linus Torvalds
'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler, timer and x86 fixes from Ingo Molnar: - A context tracking ARM build and functional fix - A handful of ARM clocksource/clockevent driver fixes - An AMD microcode patch level sysfs reporting fixlet * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: arm: Fix build error with context tracking calls * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: clocksource: em_sti: Set cpu_possible_mask to fix SMP broadcast clocksource: of: Respect device tree node status clocksource: exynos_mct: Set IRQ affinity when the CPU goes online arm: clocksource: mvebu: Use the main timer as clock source from DT * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/microcode/AMD: Fix patch level reporting for family 15h
2013-09-28kernel/params: fix handling of signed integer typesJean Delvare
Commit 6072ddc8520b ("kernel: replace strict_strto*() with kstrto*()") broke the handling of signed integer types, fix it. Signed-off-by: Jean Delvare <khali@linux-fr.org> Reported-by: Christian Kujau <lists@nerdbynature.de> Tested-by: Christian Kujau <lists@nerdbynature.de> Cc: Jingoo Han <jg1.han@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-28Merge branch 'context_tracking/fixes' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks into sched/urgent Pull context tracking ARM fix from Frederic Weisbecker. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-09-27arm: Fix build error with context tracking callsFrederic Weisbecker
ad65782fba50 (context_tracking: Optimize main APIs off case with static key) converted context tracking main APIs to inline function and left ARM asm callers behind. This can be easily fixed by making ARM calling the post static keys context tracking function. We just need to replicate the static key checks there. We'll remove these later when ARM will support the context tracking static keys. Reported-by: Guenter Roeck <linux@roeck-us.net> Reported-by: Russell King <linux@arm.linux.org.uk> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Tested-by: Kevin Hilman <khilman@linaro.org> Cc: Nicolas Pitre <nicolas.pitre@linaro.org> Cc: Anil Kumar <anilk4.v@gmail.com> Cc: Tony Lindgren <tony@atomide.com> Cc: Benoit Cousson <b-cousson@ti.com> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Russell King <linux@arm.linux.org.uk> Cc: Kevin Hilman <khilman@linaro.org>
2013-09-25Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Ingo Molnar: "Three small fixes" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/balancing: Fix cfs_rq->task_h_load calculation sched/balancing: Fix 'local->avg_load > busiest->avg_load' case in fix_small_imbalance() sched/balancing: Fix 'local->avg_load > sds->avg_load' case in calculate_imbalance()
2013-09-25Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "Assorted standalone fixes" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86/intel: Add model number for Avoton Silvermont perf: Fix capabilities bitfield compatibility in 'struct perf_event_mmap_page' perf/x86/intel/uncore: Don't use smp_processor_id() in validate_group() perf: Update ABI comment tools lib lk: Uninclude linux/magic.h in debugfs.c perf tools: Fix old GCC build error in trace-event-parse.c:parse_proc_kallsyms() perf probe: Fix finder to find lines of given function perf session: Check for SIGINT in more loops perf tools: Fix compile with libelf without get_phdrnum perf tools: Fix buildid cache handling of kallsyms with kcore perf annotate: Fix objdump line parsing offset validation perf tools: Fill in new definitions for madvise()/mmap() flags perf tools: Sharpen the libaudit dependencies test
2013-09-25rcu: Consistent rcu_is_watching() namingPaul E. McKenney
The old rcu_is_cpu_idle() function is just __rcu_is_watching() with preemption disabled. This commit therefore renames rcu_is_cpu_idle() to rcu_is_watching. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2013-09-25rcu: Change EXPORT_SYMBOL() to EXPORT_SYMBOL_GPL()Paul E. McKenney
Commit e6b80a3b (rcu: Detect illegal rcu dereference in extended quiescent state) exported the pre-existing rcu_is_cpu_idle() function using EXPORT_SYMBOL(). However, this is inconsistent with the remaining exports from RCU, which are all EXPORT_SYMBOL_GPL(). The current state of affairs means that a non-GPL module could use rcu_is_cpu_idle(), but in a CONFIG_TREE_PREEMPT_RCU=y kernel would be unable to invoke rcu_read_lock() and rcu_read_unlock(). This commit therefore makes rcu_is_cpu_idle()'s export be consistent with the rest of RCU, namely EXPORT_SYMBOL_GPL(). Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2013-09-25rcu: Is it safe to enter an RCU read-side critical section?Paul E. McKenney
There is currently no way for kernel code to determine whether it is safe to enter an RCU read-side critical section, in other words, whether or not RCU is paying attention to the currently running CPU. Given the large and increasing quantity of code shared by the idle loop and non-idle code, the this shortcoming is becoming increasingly painful. This commit therefore adds __rcu_is_watching(), which returns true if it is safe to enter an RCU read-side critical section on the currently running CPU. This function is quite fast, using only a __this_cpu_read(). However, the caller must disable preemption. Reported-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2013-09-25rcu: Throttle invoke_rcu_core() invocations due to non-lazy callbacksPaul E. McKenney
If a non-lazy callback arrives on a CPU that has previously gone idle with no non-lazy callbacks, invoke_rcu_core() forces the RCU core to run. However, it does not update the conditions, which could result in several closely spaced invocations of the RCU core, which in turn could result in an excessively high context-switch rate and resulting high overhead. This commit therefore updates the ->all_lazy and ->nonlazy_posted_snap fields to prevent closely spaced invocations. Reported-by: Tibor Billes <tbilles@gmx.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Tested-by: Tibor Billes <tbilles@gmx.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2013-09-25rcu: Throttle rcu_try_advance_all_cbs() executionPaul E. McKenney
The rcu_try_advance_all_cbs() function is invoked on each attempted entry to and every exit from idle. If this function determines that there are callbacks ready to invoke, the caller will invoke the RCU core, which in turn will result in a pair of context switches. If a CPU enters and exits idle extremely frequently, this can result in an excessive number of context switches and high CPU overhead. This commit therefore causes rcu_try_advance_all_cbs() to throttle itself, refusing to do work more than once per jiffy. Reported-by: Tibor Billes <tbilles@gmx.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Tested-by: Tibor Billes <tbilles@gmx.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2013-09-25rcu: Remove redundant code from rcu_cleanup_after_idle()Paul E. McKenney
The rcu_try_advance_all_cbs() function returns a bool saying whether or not there are callbacks ready to invoke, but rcu_cleanup_after_idle() rechecks this regardless. This commit therefore uses the value returned by rcu_try_advance_all_cbs() instead of making rcu_cleanup_after_idle() do this recheck. Reported-by: Tibor Billes <tbilles@gmx.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Tested-by: Tibor Billes <tbilles@gmx.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2013-09-24kernel/reboot.c: re-enable the function of variable reboot_defaultChuansheng Liu
Commit 1b3a5d02ee07 ("reboot: move arch/x86 reboot= handling to generic kernel") did some cleanup for reboot= command line, but it made the reboot_default inoperative. The default value of variable reboot_default should be 1, and if command line reboot= is not set, system will use the default reboot mode. [akpm@linux-foundation.org: fix comment layout] Signed-off-by: Li Fei <fei.li@intel.com> Signed-off-by: liu chuansheng <chuansheng.liu@intel.com> Acked-by: Robin Holt <robinmholt@linux.com> Cc: <stable@vger.kernel.org> [3.11.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24audit: fix endless wait in audit_log_start()Konstantin Khlebnikov
After commit 829199197a43 ("kernel/audit.c: avoid negative sleep durations") audit emitters will block forever if userspace daemon cannot handle backlog. After the timeout the waiting loop turns into busy loop and runs until daemon dies or returns back to work. This is a minimal patch for that bug. Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Richard Guy Briggs <rgb@redhat.com> Cc: Eric Paris <eparis@redhat.com> Cc: Chuck Anderson <chuck.anderson@oracle.com> Cc: Dan Duval <dan.duval@oracle.com> Cc: Dave Kleikamp <dave.kleikamp@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24watchdog: update watchdog_thresh properlyMichal Hocko
watchdog_tresh controls how often nmi perf event counter checks per-cpu hrtimer_interrupts counter and blows up if the counter hasn't changed since the last check. The counter is updated by per-cpu watchdog_hrtimer hrtimer which is scheduled with 2/5 watchdog_thresh period which guarantees that hrtimer is scheduled 2 times per the main period. Both hrtimer and perf event are started together when the watchdog is enabled. So far so good. But... But what happens when watchdog_thresh is updated from sysctl handler? proc_dowatchdog will set a new sampling period and hrtimer callback (watchdog_timer_fn) will use the new value in the next round. The problem, however, is that nobody tells the perf event that the sampling period has changed so it is ticking with the period configured when it has been set up. This might result in an ear ripping dissonance between perf and hrtimer parts if the watchdog_thresh is increased. And even worse it might lead to KABOOM if the watchdog is configured to panic on such a spurious lockup. This patch fixes the issue by updating both nmi perf even counter and hrtimers if the threshold value has changed. The nmi one is disabled and then reinitialized from scratch. This has an unpleasant side effect that the allocation of the new event might fail theoretically so the hard lockup detector would be disabled for such cpus. On the other hand such a memory allocation failure is very unlikely because the original event is deallocated right before. It would be much nicer if we just changed perf event period but there doesn't seem to be any API to do that right now. It is also unfortunate that perf_event_alloc uses GFP_KERNEL allocation unconditionally so we cannot use on_each_cpu() and do the same thing from the per-cpu context. The update from the current CPU should be safe because perf_event_disable removes the event atomically before it clears the per-cpu watchdog_ev so it cannot change anything under running handler feet. The hrtimer is simply restarted (thanks to Don Zickus who has pointed this out) if it is queued because we cannot rely it will fire&adopt to the new sampling period before a new nmi event triggers (when the treshold is decreased). [akpm@linux-foundation.org: the UP version of __smp_call_function_single ended up in the wrong place] Signed-off-by: Michal Hocko <mhocko@suse.cz> Acked-by: Don Zickus <dzickus@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Fabio Estevam <festevam@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24watchdog: update watchdog attributes atomicallyMichal Hocko
proc_dowatchdog doesn't synchronize multiple callers which might lead to confusion when two parallel callers might confuse watchdog_enable_all_cpus resp watchdog_disable_all_cpus (eg watchdog gets enabled even if watchdog_thresh was set to 0 already). This patch adds a local mutex which synchronizes callers to the sysctl handler. Signed-off-by: Michal Hocko <mhocko@suse.cz> Cc: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Don Zickus <dzickus@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-20sched/balancing: Fix cfs_rq->task_h_load calculationVladimir Davydov
Patch a003a2 (sched: Consider runnable load average in move_tasks()) sets all top-level cfs_rqs' h_load to rq->avg.load_avg_contrib, which is always 0. This mistype leads to all tasks having weight 0 when load balancing in a cpu-cgroup enabled setup. There obviously should be sum of weights of all runnable tasks there instead. Fix it. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Reviewed-by: Paul Turner <pjt@google.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1379173186-11944-1-git-send-email-vdavydov@parallels.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-09-20sched/balancing: Fix 'local->avg_load > busiest->avg_load' case in ↵Vladimir Davydov
fix_small_imbalance() In busiest->group_imb case we can come to fix_small_imbalance() with local->avg_load > busiest->avg_load. This can result in wrong imbalance fix-up, because there is the following check there where all the members are unsigned: if (busiest->avg_load - local->avg_load + scaled_busy_load_per_task >= (scaled_busy_load_per_task * imbn)) { env->imbalance = busiest->load_per_task; return; } As a result we can end up constantly bouncing tasks from one cpu to another if there are pinned tasks. Fix it by substituting the subtraction with an equivalent addition in the check. [ The bug can be caught by running 2*N cpuhogs pinned to two logical cpus belonging to different cores on an HT-enabled machine with N logical cpus: just look at se.nr_migrations growth. ] Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/ef167822e5c5b2d96cf5b0e3e4f4bdff3f0414a2.1379252740.git.vdavydov@parallels.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-09-20sched/balancing: Fix 'local->avg_load > sds->avg_load' case in ↵Vladimir Davydov
calculate_imbalance() In busiest->group_imb case we can come to calculate_imbalance() with local->avg_load >= busiest->avg_load >= sds->avg_load. This can result in imbalance overflow, because it is calculated as follows env->imbalance = min( max_pull * busiest->group_power, (sds->avg_load - local->avg_load) * local->group_power) / SCHED_POWER_SCALE; As a result we can end up constantly bouncing tasks from one cpu to another if there are pinned tasks. Fix this by skipping the assignment and assuming imbalance=0 in case local->avg_load > sds->avg_load. [ The bug can be caught by running 2*N cpuhogs pinned to two logical cpus belonging to different cores on an HT-enabled machine with N logical cpus: just look at se.nr_migrations growth. ] Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/8f596cc6bc0e5e655119dc892c9bfcad26e971f4.1379252740.git.vdavydov@parallels.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-09-20perf: Fix capabilities bitfield compatibility in 'struct perf_event_mmap_page'Peter Zijlstra
Solve the problems around the broken definition of perf_event_mmap_page:: cap_usr_time and cap_usr_rdpmc fields which used to overlap, partially fixed by: 860f085b74e9 ("perf: Fix broken union in 'struct perf_event_mmap_page'") The problem with the fix (merged in v3.12-rc1 and not yet released officially), noticed by Vince Weaver is that the new behavior is not detectable by new user-space, and that due to the reuse of the field names it's easy to mis-compile a binary if old headers are used on a new kernel or new headers are used on an old kernel. To solve all that make this change explicit, detectable and self-contained, by iterating the ABI the following way: - Always clear bit 0, and rename it to usrpage->cap_bit0, to at least not confuse old user-space binaries. RDPMC will be marked as unavailable to old binaries but that's within the ABI, this is a capability bit. - Rename bit 1 to ->cap_bit0_is_deprecated and always set it to 1, so new libraries can reliably detect that bit 0 is deprecated and perma-zero without having to check the kernel version. - Use bits 2, 3, 4 for the newly defined, correct functionality: cap_user_rdpmc : 1, /* The RDPMC instruction can be used to read counts */ cap_user_time : 1, /* The time_* fields are used */ cap_user_time_zero : 1, /* The time_zero field is used */ - Rename all the bitfield names in perf_event.h to be different from the old names, to make sure it's not possible to mis-compile it accidentally with old assumptions. The 'size' field can then be used in the future to add new fields and it will act as a natural ABI version indicator as well. Also adjust tools/perf/ userspace for the new definitions, noticed by Adrian Hunter. Reported-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Also-Fixed-by: Adrian Hunter <adrian.hunter@intel.com> Link: http://lkml.kernel.org/n/tip-zr03yxjrpXesOzzupszqglbv@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-09-18Merge branch 'timers-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer fix from Ingo Molnar: "An NTP related lockup fix" * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: timekeeping: Fix HRTICK related deadlock from ntp lock changes
2013-09-18Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Ingo Molnar: "Misc fixes" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched: Fix comment for sched_info_depart sched/Documentation: Update sched-design-CFS.txt documentation sched/debug: Take PID namespace into account sched/fair: Fix small race where child->se.parent,cfs_rq might point to invalid ones
2013-09-16sched: Fix comment for sched_info_departMichael S. Tsirkin
sched_info_depart seems to be only called from sched_info_switch(), so only on involuntary task switch. Fix the comment to match. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Link: http://lkml.kernel.org/r/20130916083036.GA1113@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-09-13Merge git://git.kvack.org/~bcrl/aio-nextLinus Torvalds
Pull aio changes from Ben LaHaise: "First off, sorry for this pull request being late in the merge window. Al had raised a couple of concerns about 2 items in the series below. I addressed the first issue (the race introduced by Gu's use of mm_populate()), but he has not provided any further details on how he wants to rework the anon_inode.c changes (which were sent out months ago but have yet to be commented on). The bulk of the changes have been sitting in the -next tree for a few months, with all the issues raised being addressed" * git://git.kvack.org/~bcrl/aio-next: (22 commits) aio: rcu_read_lock protection for new rcu_dereference calls aio: fix race in ring buffer page lookup introduced by page migration support aio: fix rcu sparse warnings introduced by ioctx table lookup patch aio: remove unnecessary debugging from aio_free_ring() aio: table lookup: verify ctx pointer staging/lustre: kiocb->ki_left is removed aio: fix error handling and rcu usage in "convert the ioctx list to table lookup v3" aio: be defensive to ensure request batching is non-zero instead of BUG_ON() aio: convert the ioctx list to table lookup v3 aio: double aio_max_nr in calculations aio: Kill ki_dtor aio: Kill ki_users aio: Kill unneeded kiocb members aio: Kill aio_rw_vect_retry() aio: Don't use ctx->tail unnecessarily aio: io_cancel() no longer returns the io_event aio: percpu ioctx refcount aio: percpu reqs_available aio: reqs_active -> reqs_available aio: fix build when migration is disabled ...
2013-09-13Remove GENERIC_HARDIRQ config optionMartin Schwidefsky
After the last architecture switched to generic hard irqs the config options HAVE_GENERIC_HARDIRQS & GENERIC_HARDIRQS and the related code for !CONFIG_GENERIC_HARDIRQS can be removed. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-09-12Merge branch 'akpm' (patches from Andrew Morton)Linus Torvalds
Merge more patches from Andrew Morton: "The rest of MM. Plus one misc cleanup" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (35 commits) mm/Kconfig: add MMU dependency for MIGRATION. kernel: replace strict_strto*() with kstrto*() mm, thp: count thp_fault_fallback anytime thp fault fails thp: consolidate code between handle_mm_fault() and do_huge_pmd_anonymous_page() thp: do_huge_pmd_anonymous_page() cleanup thp: move maybe_pmd_mkwrite() out of mk_huge_pmd() mm: cleanup add_to_page_cache_locked() thp: account anon transparent huge pages into NR_ANON_PAGES truncate: drop 'oldsize' truncate_pagecache() parameter mm: make lru_add_drain_all() selective memcg: document cgroup dirty/writeback memory statistics memcg: add per cgroup writeback pages accounting memcg: check for proper lock held in mem_cgroup_update_page_stat memcg: remove MEMCG_NR_FILE_MAPPED memcg: reduce function dereference memcg: avoid overflow caused by PAGE_ALIGN memcg: rename RESOURCE_MAX to RES_COUNTER_MAX memcg: correct RESOURCE_MAX to ULLONG_MAX mm: memcg: do not trap chargers with full callstack on OOM mm: memcg: rework and document OOM waiting and wakeup ...
2013-09-12kernel: replace strict_strto*() with kstrto*()Jingoo Han
The usage of strict_strto*() is not preferred, because strict_strto*() is obsolete. Thus, kstrto*() should be used. Signed-off-by: Jingoo Han <jg1.han@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12memcg: reduce function dereferenceSha Zhengju
This function dereferences res far too often, so optimize it. Signed-off-by: Sha Zhengju <handai.szj@taobao.com> Signed-off-by: Qiang Huang <h.huangqiang@huawei.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Jeff Liu <jeff.liu@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12memcg: avoid overflow caused by PAGE_ALIGNSha Zhengju
Since PAGE_ALIGN is aligning up(the next page boundary), so after PAGE_ALIGN, the value might be overflow, such as write the MAX value to *.limit_in_bytes. $ cat /cgroup/memory/memory.limit_in_bytes 18446744073709551615 # echo 18446744073709551615 > /cgroup/memory/memory.limit_in_bytes bash: echo: write error: Invalid argument Some user programs might depend on such behaviours(like libcg, we read the value in snapshot, then use the value to reset cgroup later), and that will cause confusion. So we need to fix it. Signed-off-by: Sha Zhengju <handai.szj@taobao.com> Signed-off-by: Qiang Huang <h.huangqiang@huawei.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Jeff Liu <jeff.liu@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12memcg: rename RESOURCE_MAX to RES_COUNTER_MAXSha Zhengju
RESOURCE_MAX is far too general name, change it to RES_COUNTER_MAX. Signed-off-by: Sha Zhengju <handai.szj@taobao.com> Signed-off-by: Qiang Huang <h.huangqiang@huawei.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Jeff Liu <jeff.liu@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs pile 4 from Al Viro: "list_lru pile, mostly" This came out of Andrew's pile, Al ended up doing the merge work so that Andrew didn't have to. Additionally, a few fixes. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (42 commits) super: fix for destroy lrus list_lru: dynamically adjust node arrays shrinker: Kill old ->shrink API. shrinker: convert remaining shrinkers to count/scan API staging/lustre/libcfs: cleanup linux-mem.h staging/lustre/ptlrpc: convert to new shrinker API staging/lustre/obdclass: convert lu_object shrinker to count/scan API staging/lustre/ldlm: convert to shrinkers to count/scan API hugepage: convert huge zero page shrinker to new shrinker API i915: bail out earlier when shrinker cannot acquire mutex drivers: convert shrinkers to new count/scan API fs: convert fs shrinkers to new scan/count API xfs: fix dquot isolation hang xfs-convert-dquot-cache-lru-to-list_lru-fix xfs: convert dquot cache lru to list_lru xfs: rework buffer dispose list tracking xfs-convert-buftarg-lru-to-generic-code-fix xfs: convert buftarg LRU to generic code fs: convert inode and dentry shrinking to be node aware vmscan: per-node deferred work ...
2013-09-12Merge tag 'pm+acpi-fixes-3.12-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull ACPI and power management fixes from Rafael Wysocki: "All of these commits are fixes that have emerged recently and some of them fix bugs introduced during this merge window. Specifics: 1) ACPI-based PCI hotplug (ACPIPHP) fixes related to spurious events After the recent ACPIPHP changes we've seen some interesting breakage on a system that triggers device check notifications during boot for non-existing devices. Although those notifications are really spurious, we should be able to deal with them nevertheless and that shouldn't introduce too much overhead. Four commits to make that work properly. 2) Memory hotplug and hibernation mutual exclusion rework This was maent to be a cleanup, but it happens to fix a classical ABBA deadlock between system suspend/hibernation and ACPI memory hotplug which is possible if they are started roughly at the same time. Three commits rework memory hotplug so that it doesn't acquire pm_mutex and make hibernation use device_hotplug_lock which prevents it from racing with memory hotplug. 3) ACPI Intel LPSS (Low-Power Subsystem) driver crash fix The ACPI LPSS driver crashes during boot on Apple Macbook Air with Haswell that has slightly unusual BIOS configuration in which one of the LPSS device's _CRS method doesn't return all of the information expected by the driver. Fix from Mika Westerberg, for stable. 4) ACPICA fix related to Store->ArgX operation AML interpreter fix for obscure breakage that causes AML to be executed incorrectly on some machines (observed in practice). From Bob Moore. 5) ACPI core fix for PCI ACPI device objects lookup There still are cases in which there is more than one ACPI device object matching a given PCI device and we don't choose the one that the BIOS expects us to choose, so this makes the lookup take more criteria into account in those cases. 6) Fix to prevent cpuidle from crashing in some rare cases If the result of cpuidle_get_driver() is NULL, which can happen on some systems, cpuidle_driver_ref() will crash trying to use that pointer and the Daniel Fu's fix prevents that from happening. 7) cpufreq fixes related to CPU hotplug Stephen Boyd reported a number of concurrency problems with cpufreq related to CPU hotplug which are addressed by a series of fixes from Srivatsa S Bhat and Viresh Kumar. 8) cpufreq fix for time conversion in time_in_state attribute Time conversion carried out by cpufreq when user space attempts to read /sys/devices/system/cpu/cpu*/cpufreq/stats/time_in_state won't work correcty if cputime_t doesn't map directly to jiffies. Fix from Andreas Schwab. 9) Revert of a troublesome cpufreq commit Commit 7c30ed5 (cpufreq: make sure frequency transitions are serialized) was intended to address some known concurrency problems in cpufreq related to the ordering of transitions, but unfortunately it introduced several problems of its own, so I decided to revert it now and address the original problems later in a more robust way. 10) Intel Haswell CPU models for intel_pstate from Nell Hardcastle. 11) cpufreq fixes related to system suspend/resume The recent cpufreq changes that made it preserve CPU sysfs attributes over suspend/resume cycles introduced a possible NULL pointer dereference that caused it to crash during the second attempt to suspend. Three commits from Srivatsa S Bhat fix that problem and a couple of related issues. 12) cpufreq locking fix cpufreq_policy_restore() should acquire the lock for reading, but it acquires it for writing. Fix from Lan Tianyu" * tag 'pm+acpi-fixes-3.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (25 commits) cpufreq: Acquire the lock in cpufreq_policy_restore() for reading cpufreq: Prevent problems in update_policy_cpu() if last_cpu == new_cpu cpufreq: Restructure if/else block to avoid unintended behavior cpufreq: Fix crash in cpufreq-stats during suspend/resume intel_pstate: Add Haswell CPU models Revert "cpufreq: make sure frequency transitions are serialized" cpufreq: Use signed type for 'ret' variable, to store negative error values cpufreq: Remove temporary fix for race between CPU hotplug and sysfs-writes cpufreq: Synchronize the cpufreq store_*() routines with CPU hotplug cpufreq: Invoke __cpufreq_remove_dev_finish() after releasing cpu_hotplug.lock cpufreq: Split __cpufreq_remove_dev() into two parts cpufreq: Fix wrong time unit conversion cpufreq: serialize calls to __cpufreq_governor() cpufreq: don't allow governor limits to be changed when it is disabled ACPI / bind: Prefer device objects with _STA to those without it ACPI / hotplug / PCI: Avoid parent bus rescans on spurious device checks ACPI / hotplug / PCI: Use _OST to notify firmware about notify status ACPI / hotplug / PCI: Avoid doing too much for spurious notifies ACPICA: Fix for a Store->ArgX when ArgX contains a reference to a field. ACPI / hotplug / PCI: Don't trim devices before scanning the namespace ...