Upstreaming: Alexey's patchset "powerpc/spapr/vfio: Put pages on VFIO container shutdown" #4

paulusmack · 2016-11-02T09:45:51Z

This is to record the fact that hostos-1.0 includes the patch set "powerpc/spapr/vfio: Put pages on VFIO container shutdown", which is not upstream yet. This patch set fixes a bug where memory used by a guest can remain pinned for a long time after the guest is terminated.

The commits are:

5fa3141 ("powerpc/iommu: Pass mm_struct to init/cleanup helpers", 2016-10-24)
e96f99c ("powerpc/iommu: Stop using @current in mm_iommu_xxx", 2016-10-24)
f27109c ("vfio/spapr: Reference mm in tce_container", 2016-10-24)
200b22d ("powerpc/mm/iommu, vfio/spapr: Put pages on VFIO container shutdown", 2016-10-24)

The text was updated successfully, but these errors were encountered:

We used to use generic implementation of dma_map_ops.mmap which is dma_common_mmap() but that only worked for simpler cached mappings when vaddr = paddr. If a driver requests uncached DMA buffer kernel maps it to virtual address so that MMU gets involved and page uncached status takes into account. In that case usage of dma_common_mmap() lead to mapping of vaddr to vaddr for user-space which is obviously wrong. For more detals please refer to verbose explanation here [1]. So here we implement our own version of mmap() which always deals with dma_addr and maps underlying memory to user-space properly (note that DMA buffer mapped to user-space is always uncached because there's no way to properly manage cache from user-space). [1] https://lkml.org/lkml/2016/10/26/973 Reviewed-by: Catalin Marinas <[email protected]> Cc: Marek Szyprowski <[email protected]> Cc: <[email protected]> #4.5+ Signed-off-by: Alexey Brodkin <[email protected]> Signed-off-by: Vineet Gupta <[email protected]>

The current code doesn't even compile as somehow the inline assembly can't see the register names defined as ARC_RTC_* I'm pretty sure It worked when I first got it merged, but the tools were definitely different then. So better to write this in "C" anyways. CC: [email protected] #4.2+ Acked-by: Daniel Lezcano <[email protected]> Signed-off-by: Vineet Gupta <[email protected]>

Both ACPI and MP specifications require that the APIC id in the respective tables must be the same as the APIC id in CPUID. The kernel retrieves the physical package id from the APIC id during the ACPI/MP table scan and builds the physical to logical package map. The physical package id which is used after a CPU comes up is retrieved from CPUID. So we rely on ACPI/MP tables and CPUID agreeing in that respect. There exist VMware and XEN implementations which violate the spec. As a result the physical to logical package map, which relies on the ACPI/MP tables does not work on those systems, because the CPUID initialized physical package id does not match the firmware id. This causes system crashes and malfunction due to invalid package mappings. The only way to cure this is to sanitize the physical package id after the CPUID enumeration and yell when the APIC ids are different. Fix up the initial APIC id, which is fine as it is only used printout purposes. If the physical package IDs differ yell and use the package information from the ACPI/MP tables so the existing logical package map just works. Chas provided the resulting dmesg output for his affected 4 virtual sockets, 1 core per socket VM: [Firmware Bug]: CPU1: APIC id mismatch. Firmware: 1 CPUID: 2 [Firmware Bug]: CPU1: Using firmware package id 1 instead of 2 .... Reported-and-tested-by: "Charles (Chas) Williams" <[email protected]>, Reported-by: M. Vefa Bicakci <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Sebastian Andrzej Siewior <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Alok Kataria <[email protected]> Cc: Boris Ostrovsky <[email protected]> Cc: #4.6+ <stable@vger,kernel.org> Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1611091613540.3501@nanos Signed-off-by: Thomas Gleixner <[email protected]>

When booting up LDOM, find_node() warns that a physical address doesn't match a NUMA node. WARNING: CPU: 0 PID: 0 at arch/sparc/mm/init_64.c:835 find_node+0xf4/0x120 find_node: A physical address doesn't match a NUMA node rule. Some physical memory will be owned by node 0.Modules linked in: CPU: 0 PID: 0 Comm: swapper Not tainted 4.9.0-rc3 #4 Call Trace: [0000000000468ba0] __warn+0xc0/0xe0 [0000000000468c74] warn_slowpath_fmt+0x34/0x60 [00000000004592f4] find_node+0xf4/0x120 [0000000000dd0774] add_node_ranges+0x38/0xe4 [0000000000dd0b1c] numa_parse_mdesc+0x268/0x2e4 [0000000000dd0e9c] bootmem_init+0xb8/0x160 [0000000000dd174c] paging_init+0x808/0x8fc [0000000000dcb0d0] setup_arch+0x2c8/0x2f0 [0000000000dc68a0] start_kernel+0x48/0x424 [0000000000dcb374] start_early_boot+0x27c/0x28c [0000000000a32c08] tlb_fixup_done+0x4c/0x64 [0000000000027f08] 0x27f08 It is because linux use an internal structure node_masks[] to keep the best memory latency node only. However, LDOM mdesc can contain single latency-group with multiple memory latency nodes. If the address doesn't match the best latency node within node_masks[], it should check for an alternative via mdesc. The warning message should only be printed if the address doesn't match any node_masks[] nor within mdesc. To minimize the impact of searching mdesc every time, the last matched mask and index is stored in a variable. Signed-off-by: Thomas Tai <[email protected]> Reviewed-by: Chris Hyser <[email protected]> Reviewed-by: Liam Merwick <[email protected]> Signed-off-by: David S. Miller <[email protected]>

commit 1c3c909 broke PAE40. Macro pfn_pte(pfn, prot) creates paddr from pfn, but the page shift was getting truncated to 32 bits since we lost the proper cast to 64 bits (for PAE400 Instead of reverting that commit, use a better helper which is 32/64 bits safe just like ARM implementation. Fixes: 1c3c909 ("ARC: mm: fix build breakage with STRICT_MM_TYPECHECKS") Cc: <[email protected]> #4.4+ Signed-off-by: Yuriy Kolerov <[email protected]> [vgupta: massaged changelog] Signed-off-by: Vineet Gupta <[email protected]>

We cannot do printk() from tk_debug_account_sleep_time(), because tk_debug_account_sleep_time() is called under tk_core seq lock. The reason why printk() is unsafe there is that console_sem may invoke scheduler (up()->wake_up_process()->activate_task()), which, in turn, can return back to timekeeping code, for instance, via get_time()->ktime_get(), deadlocking the system on tk_core seq lock. [ 48.950592] ====================================================== [ 48.950622] [ INFO: possible circular locking dependency detected ] [ 48.950622] 4.10.0-rc7-next-20170213+ torvalds#101 Not tainted [ 48.950622] ------------------------------------------------------- [ 48.950622] kworker/0:0/3 is trying to acquire lock: [ 48.950653] (tk_core){----..}, at: [<c01cc624>] retrigger_next_event+0x4c/0x90 [ 48.950683] but task is already holding lock: [ 48.950683] (hrtimer_bases.lock){-.-...}, at: [<c01cc610>] retrigger_next_event+0x38/0x90 [ 48.950714] which lock already depends on the new lock. [ 48.950714] the existing dependency chain (in reverse order) is: [ 48.950714] -> #5 (hrtimer_bases.lock){-.-...}: [ 48.950744] _raw_spin_lock_irqsave+0x50/0x64 [ 48.950775] lock_hrtimer_base+0x28/0x58 [ 48.950775] hrtimer_start_range_ns+0x20/0x5c8 [ 48.950775] __enqueue_rt_entity+0x320/0x360 [ 48.950805] enqueue_rt_entity+0x2c/0x44 [ 48.950805] enqueue_task_rt+0x24/0x94 [ 48.950836] ttwu_do_activate+0x54/0xc0 [ 48.950836] try_to_wake_up+0x248/0x5c8 [ 48.950836] __setup_irq+0x420/0x5f0 [ 48.950836] request_threaded_irq+0xdc/0x184 [ 48.950866] devm_request_threaded_irq+0x58/0xa4 [ 48.950866] omap_i2c_probe+0x530/0x6a0 [ 48.950897] platform_drv_probe+0x50/0xb0 [ 48.950897] driver_probe_device+0x1f8/0x2cc [ 48.950897] __driver_attach+0xc0/0xc4 [ 48.950927] bus_for_each_dev+0x6c/0xa0 [ 48.950927] bus_add_driver+0x100/0x210 [ 48.950927] driver_register+0x78/0xf4 [ 48.950958] do_one_initcall+0x3c/0x16c [ 48.950958] kernel_init_freeable+0x20c/0x2d8 [ 48.950958] kernel_init+0x8/0x110 [ 48.950988] ret_from_fork+0x14/0x24 [ 48.950988] -> #4 (&rt_b->rt_runtime_lock){-.-...}: [ 48.951019] _raw_spin_lock+0x40/0x50 [ 48.951019] rq_offline_rt+0x9c/0x2bc [ 48.951019] set_rq_offline.part.2+0x2c/0x58 [ 48.951049] rq_attach_root+0x134/0x144 [ 48.951049] cpu_attach_domain+0x18c/0x6f4 [ 48.951049] build_sched_domains+0xba4/0xd80 [ 48.951080] sched_init_smp+0x68/0x10c [ 48.951080] kernel_init_freeable+0x160/0x2d8 [ 48.951080] kernel_init+0x8/0x110 [ 48.951080] ret_from_fork+0x14/0x24 [ 48.951110] -> #3 (&rq->lock){-.-.-.}: [ 48.951110] _raw_spin_lock+0x40/0x50 [ 48.951141] task_fork_fair+0x30/0x124 [ 48.951141] sched_fork+0x194/0x2e0 [ 48.951141] copy_process.part.5+0x448/0x1a20 [ 48.951171] _do_fork+0x98/0x7e8 [ 48.951171] kernel_thread+0x2c/0x34 [ 48.951171] rest_init+0x1c/0x18c [ 48.951202] start_kernel+0x35c/0x3d4 [ 48.951202] 0x8000807c [ 48.951202] -> #2 (&p->pi_lock){-.-.-.}: [ 48.951232] _raw_spin_lock_irqsave+0x50/0x64 [ 48.951232] try_to_wake_up+0x30/0x5c8 [ 48.951232] up+0x4c/0x60 [ 48.951263] __up_console_sem+0x2c/0x58 [ 48.951263] console_unlock+0x3b4/0x650 [ 48.951263] vprintk_emit+0x270/0x474 [ 48.951293] vprintk_default+0x20/0x28 [ 48.951293] printk+0x20/0x30 [ 48.951324] kauditd_hold_skb+0x94/0xb8 [ 48.951324] kauditd_thread+0x1a4/0x56c [ 48.951324] kthread+0x104/0x148 [ 48.951354] ret_from_fork+0x14/0x24 [ 48.951354] -> #1 ((console_sem).lock){-.....}: [ 48.951385] _raw_spin_lock_irqsave+0x50/0x64 [ 48.951385] down_trylock+0xc/0x2c [ 48.951385] __down_trylock_console_sem+0x24/0x80 [ 48.951385] console_trylock+0x10/0x8c [ 48.951416] vprintk_emit+0x264/0x474 [ 48.951416] vprintk_default+0x20/0x28 [ 48.951416] printk+0x20/0x30 [ 48.951446] tk_debug_account_sleep_time+0x5c/0x70 [ 48.951446] __timekeeping_inject_sleeptime.constprop.3+0x170/0x1a0 [ 48.951446] timekeeping_resume+0x218/0x23c [ 48.951477] syscore_resume+0x94/0x42c [ 48.951477] suspend_enter+0x554/0x9b4 [ 48.951477] suspend_devices_and_enter+0xd8/0x4b4 [ 48.951507] enter_state+0x934/0xbd4 [ 48.951507] pm_suspend+0x14/0x70 [ 48.951507] state_store+0x68/0xc8 [ 48.951538] kernfs_fop_write+0xf4/0x1f8 [ 48.951538] __vfs_write+0x1c/0x114 [ 48.951538] vfs_write+0xa0/0x168 [ 48.951568] SyS_write+0x3c/0x90 [ 48.951568] __sys_trace_return+0x0/0x10 [ 48.951568] -> #0 (tk_core){----..}: [ 48.951599] lock_acquire+0xe0/0x294 [ 48.951599] ktime_get_update_offsets_now+0x5c/0x1d4 [ 48.951629] retrigger_next_event+0x4c/0x90 [ 48.951629] on_each_cpu+0x40/0x7c [ 48.951629] clock_was_set_work+0x14/0x20 [ 48.951660] process_one_work+0x2b4/0x808 [ 48.951660] worker_thread+0x3c/0x550 [ 48.951660] kthread+0x104/0x148 [ 48.951690] ret_from_fork+0x14/0x24 [ 48.951690] other info that might help us debug this: [ 48.951690] Chain exists of: tk_core --> &rt_b->rt_runtime_lock --> hrtimer_bases.lock [ 48.951721] Possible unsafe locking scenario: [ 48.951721] CPU0 CPU1 [ 48.951721] ---- ---- [ 48.951721] lock(hrtimer_bases.lock); [ 48.951751] lock(&rt_b->rt_runtime_lock); [ 48.951751] lock(hrtimer_bases.lock); [ 48.951751] lock(tk_core); [ 48.951782] *** DEADLOCK *** [ 48.951782] 3 locks held by kworker/0:0/3: [ 48.951782] #0: ("events"){.+.+.+}, at: [<c0156590>] process_one_work+0x1f8/0x808 [ 48.951812] #1: (hrtimer_work){+.+...}, at: [<c0156590>] process_one_work+0x1f8/0x808 [ 48.951843] #2: (hrtimer_bases.lock){-.-...}, at: [<c01cc610>] retrigger_next_event+0x38/0x90 [ 48.951843] stack backtrace: [ 48.951873] CPU: 0 PID: 3 Comm: kworker/0:0 Not tainted 4.10.0-rc7-next-20170213+ [ 48.951904] Workqueue: events clock_was_set_work [ 48.951904] [<c0110208>] (unwind_backtrace) from [<c010c224>] (show_stack+0x10/0x14) [ 48.951934] [<c010c224>] (show_stack) from [<c04ca6c0>] (dump_stack+0xac/0xe0) [ 48.951934] [<c04ca6c0>] (dump_stack) from [<c019b5cc>] (print_circular_bug+0x1d0/0x308) [ 48.951965] [<c019b5cc>] (print_circular_bug) from [<c019d2a8>] (validate_chain+0xf50/0x1324) [ 48.951965] [<c019d2a8>] (validate_chain) from [<c019ec18>] (__lock_acquire+0x468/0x7e8) [ 48.951995] [<c019ec18>] (__lock_acquire) from [<c019f634>] (lock_acquire+0xe0/0x294) [ 48.951995] [<c019f634>] (lock_acquire) from [<c01d0ea0>] (ktime_get_update_offsets_now+0x5c/0x1d4) [ 48.952026] [<c01d0ea0>] (ktime_get_update_offsets_now) from [<c01cc624>] (retrigger_next_event+0x4c/0x90) [ 48.952026] [<c01cc624>] (retrigger_next_event) from [<c01e4e24>] (on_each_cpu+0x40/0x7c) [ 48.952056] [<c01e4e24>] (on_each_cpu) from [<c01cafc4>] (clock_was_set_work+0x14/0x20) [ 48.952056] [<c01cafc4>] (clock_was_set_work) from [<c015664c>] (process_one_work+0x2b4/0x808) [ 48.952087] [<c015664c>] (process_one_work) from [<c0157774>] (worker_thread+0x3c/0x550) [ 48.952087] [<c0157774>] (worker_thread) from [<c015d644>] (kthread+0x104/0x148) [ 48.952087] [<c015d644>] (kthread) from [<c0107830>] (ret_from_fork+0x14/0x24) Replace printk() with printk_deferred(), which does not call into the scheduler. Fixes: 0bf43f1 ("timekeeping: Prints the amounts of time spent during suspend") Reported-and-tested-by: Tony Lindgren <[email protected]> Signed-off-by: Sergey Senozhatsky <[email protected]> Cc: Petr Mladek <[email protected]> Cc: Sergey Senozhatsky <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: "Rafael J . Wysocki" <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: John Stultz <[email protected]> Cc: "[4.9+]" <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Thomas Gleixner <[email protected]>

…_EXT commit 998d757 upstream. If there is no OPREGION_ASLE_EXT then a VBT stored in mailbox open-power-host-os#4 may use the ASLE_EXT parts of the opregion. Adjust the vbt_size calculation for a vbt in mailbox open-power-host-os#4 for this. This fixes the driver not finding the VBT on a jumper ezpad mini3 cherrytrail tablet and on a ACER SW5_017 machine. Signed-off-by: Hans de Goede <[email protected]> Signed-off-by: Jani Nikula <[email protected]> Link: http://patchwork.freedesktop.org/patch/msgid/[email protected] (cherry picked from commit dfb65e7) Signed-off-by: Jani Nikula <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>

[ Upstream commit d5afb6f ] The code where sk_clone() came from created a new socket and locked it, but then, on the error path didn't unlock it. This problem stayed there for a long while, till b0691c8 ("net: Unlock sock before calling sk_free()") fixed it, but unfortunately the callers of sk_clone() (now sk_clone_locked()) were not audited and the one in dccp_create_openreq_child() remained. Now in the age of the syskaller fuzzer, this was finally uncovered, as reported by Dmitry: ---- 8< ---- I've got the following report while running syzkaller fuzzer on 86292b3 ("Merge branch 'akpm' (patches from Andrew)") [ BUG: held lock freed! ] 4.10.0+ torvalds#234 Not tainted ------------------------- syz-executor6/6898 is freeing memory ffff88006286cac0-ffff88006286d3b7, with a lock still held there! (slock-AF_INET6){+.-...}, at: [<ffffffff8362c2c9>] spin_lock include/linux/spinlock.h:299 [inline] (slock-AF_INET6){+.-...}, at: [<ffffffff8362c2c9>] sk_clone_lock+0x3d9/0x12c0 net/core/sock.c:1504 5 locks held by syz-executor6/6898: #0: (sk_lock-AF_INET6){+.+.+.}, at: [<ffffffff839a34b4>] lock_sock include/net/sock.h:1460 [inline] #0: (sk_lock-AF_INET6){+.+.+.}, at: [<ffffffff839a34b4>] inet_stream_connect+0x44/0xa0 net/ipv4/af_inet.c:681 #1: (rcu_read_lock){......}, at: [<ffffffff83bc1c2a>] inet6_csk_xmit+0x12a/0x5d0 net/ipv6/inet6_connection_sock.c:126 open-power-host-os#2: (rcu_read_lock){......}, at: [<ffffffff8369b424>] __skb_unlink include/linux/skbuff.h:1767 [inline] open-power-host-os#2: (rcu_read_lock){......}, at: [<ffffffff8369b424>] __skb_dequeue include/linux/skbuff.h:1783 [inline] open-power-host-os#2: (rcu_read_lock){......}, at: [<ffffffff8369b424>] process_backlog+0x264/0x730 net/core/dev.c:4835 open-power-host-os#3: (rcu_read_lock){......}, at: [<ffffffff83aeb5c0>] ip6_input_finish+0x0/0x1700 net/ipv6/ip6_input.c:59 open-power-host-os#4: (slock-AF_INET6){+.-...}, at: [<ffffffff8362c2c9>] spin_lock include/linux/spinlock.h:299 [inline] open-power-host-os#4: (slock-AF_INET6){+.-...}, at: [<ffffffff8362c2c9>] sk_clone_lock+0x3d9/0x12c0 net/core/sock.c:1504 Fix it just like was done by b0691c8 ("net: Unlock sock before calling sk_free()"). Reported-by: Dmitry Vyukov <[email protected]> Cc: Cong Wang <[email protected]> Cc: Eric Dumazet <[email protected]> Cc: Gerrit Renker <[email protected]> Cc: Thomas Gleixner <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>

commit 95a4960 upstream. When iterating busy requests in timeout handler, if the STARTED flag of one request isn't set, that means the request is being processed in block layer or driver, and isn't submitted to hardware yet. In current implementation of blk_mq_check_expired(), if the request queue becomes dying, un-started requests are handled as being completed/freed immediately. This way is wrong, and can cause rq corruption or double allocation[1][2], when doing I/O and removing&resetting NVMe device at the sametime. This patch fixes several issues reported by Yi Zhang. [1]. oops log 1 [ 581.789754] ------------[ cut here ]------------ [ 581.789758] kernel BUG at block/blk-mq.c:374! [ 581.789760] invalid opcode: 0000 [#1] SMP [ 581.789761] Modules linked in: vfat fat ipmi_ssif intel_rapl sb_edac edac_core x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm nvme irqbypass crct10dif_pclmul nvme_core crc32_pclmul ghash_clmulni_intel intel_cstate ipmi_si mei_me ipmi_devintf intel_uncore sg ipmi_msghandler intel_rapl_perf iTCO_wdt mei iTCO_vendor_support mxm_wmi lpc_ich dcdbas shpchp pcspkr acpi_power_meter wmi nfsd auth_rpcgss nfs_acl lockd dm_multipath grace sunrpc ip_tables xfs libcrc32c sd_mod mgag200 i2c_algo_bit drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm drm ahci libahci crc32c_intel tg3 libata megaraid_sas i2c_core ptp fjes pps_core dm_mirror dm_region_hash dm_log dm_mod [ 581.789796] CPU: 1 PID: 1617 Comm: kworker/1:1H Not tainted 4.10.0.bz1420297+ open-power-host-os#4 [ 581.789797] Hardware name: Dell Inc. PowerEdge R730xd/072T6D, BIOS 2.2.5 09/06/2016 [ 581.789804] Workqueue: kblockd blk_mq_timeout_work [ 581.789806] task: ffff8804721c8000 task.stack: ffffc90006ee4000 [ 581.789809] RIP: 0010:blk_mq_end_request+0x58/0x70 [ 581.789810] RSP: 0018:ffffc90006ee7d50 EFLAGS: 00010202 [ 581.789811] RAX: 0000000000000001 RBX: ffff8802e4195340 RCX: ffff88028e2f4b88 [ 581.789812] RDX: 0000000000001000 RSI: 0000000000001000 RDI: 0000000000000000 [ 581.789813] RBP: ffffc90006ee7d60 R08: 0000000000000003 R09: ffff88028e2f4b00 [ 581.789814] R10: 0000000000001000 R11: 0000000000000001 R12: 00000000fffffffb [ 581.789815] R13: ffff88042abe5780 R14: 000000000000002d R15: ffff88046fbdff80 [ 581.789817] FS: 0000000000000000(0000) GS:ffff88047fc00000(0000) knlGS:0000000000000000 [ 581.789818] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 581.789819] CR2: 00007f64f403a008 CR3: 000000014d078000 CR4: 00000000001406e0 [ 581.789820] Call Trace: [ 581.789825] blk_mq_check_expired+0x76/0x80 [ 581.789828] bt_iter+0x45/0x50 [ 581.789830] blk_mq_queue_tag_busy_iter+0xdd/0x1f0 [ 581.789832] ? blk_mq_rq_timed_out+0x70/0x70 [ 581.789833] ? blk_mq_rq_timed_out+0x70/0x70 [ 581.789840] ? __switch_to+0x140/0x450 [ 581.789841] blk_mq_timeout_work+0x88/0x170 [ 581.789845] process_one_work+0x165/0x410 [ 581.789847] worker_thread+0x137/0x4c0 [ 581.789851] kthread+0x101/0x140 [ 581.789853] ? rescuer_thread+0x3b0/0x3b0 [ 581.789855] ? kthread_park+0x90/0x90 [ 581.789860] ret_from_fork+0x2c/0x40 [ 581.789861] Code: 48 85 c0 74 0d 44 89 e6 48 89 df ff d0 5b 41 5c 5d c3 48 8b bb 70 01 00 00 48 85 ff 75 0f 48 89 df e8 7d f0 ff ff 5b 41 5c 5d c3 <0f> 0b e8 71 f0 ff ff 90 eb e9 0f 1f 40 00 66 2e 0f 1f 84 00 00 [ 581.789882] RIP: blk_mq_end_request+0x58/0x70 RSP: ffffc90006ee7d50 [ 581.789889] ---[ end trace bcaf03d9a14a0a70 ]--- [2]. oops log2 [ 6984.857362] BUG: unable to handle kernel NULL pointer dereference at 0000000000000010 [ 6984.857372] IP: nvme_queue_rq+0x6e6/0x8cd [nvme] [ 6984.857373] PGD 0 [ 6984.857374] [ 6984.857376] Oops: 0000 [#1] SMP [ 6984.857379] Modules linked in: ipmi_ssif vfat fat intel_rapl sb_edac edac_core x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel ipmi_si iTCO_wdt iTCO_vendor_support mxm_wmi ipmi_devintf intel_cstate sg dcdbas intel_uncore mei_me intel_rapl_perf mei pcspkr lpc_ich ipmi_msghandler shpchp acpi_power_meter wmi nfsd auth_rpcgss dm_multipath nfs_acl lockd grace sunrpc ip_tables xfs libcrc32c sd_mod mgag200 i2c_algo_bit drm_kms_helper syscopyarea sysfillrect crc32c_intel sysimgblt fb_sys_fops ttm nvme drm nvme_core ahci libahci i2c_core tg3 libata ptp megaraid_sas pps_core fjes dm_mirror dm_region_hash dm_log dm_mod [ 6984.857416] CPU: 7 PID: 1635 Comm: kworker/7:1H Not tainted 4.10.0-2.el7.bz1420297.x86_64 #1 [ 6984.857417] Hardware name: Dell Inc. PowerEdge R730xd/072T6D, BIOS 2.2.5 09/06/2016 [ 6984.857427] Workqueue: kblockd blk_mq_run_work_fn [ 6984.857429] task: ffff880476e3da00 task.stack: ffffc90002e90000 [ 6984.857432] RIP: 0010:nvme_queue_rq+0x6e6/0x8cd [nvme] [ 6984.857433] RSP: 0018:ffffc90002e93c50 EFLAGS: 00010246 [ 6984.857434] RAX: 0000000000000000 RBX: ffff880275646600 RCX: 0000000000001000 [ 6984.857435] RDX: 0000000000000fff RSI: 00000002fba2a000 RDI: ffff8804734e6950 [ 6984.857436] RBP: ffffc90002e93d30 R08: 0000000000002000 R09: 0000000000001000 [ 6984.857437] R10: 0000000000001000 R11: 0000000000000000 R12: ffff8804741d8000 [ 6984.857438] R13: 0000000000000040 R14: ffff880475649f80 R15: ffff8804734e6780 [ 6984.857439] FS: 0000000000000000(0000) GS:ffff88047fcc0000(0000) knlGS:0000000000000000 [ 6984.857440] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 6984.857442] CR2: 0000000000000010 CR3: 0000000001c09000 CR4: 00000000001406e0 [ 6984.857443] Call Trace: [ 6984.857451] ? mempool_free+0x2b/0x80 [ 6984.857455] ? bio_free+0x4e/0x60 [ 6984.857459] blk_mq_dispatch_rq_list+0xf5/0x230 [ 6984.857462] blk_mq_process_rq_list+0x133/0x170 [ 6984.857465] __blk_mq_run_hw_queue+0x8c/0xa0 [ 6984.857467] blk_mq_run_work_fn+0x12/0x20 [ 6984.857473] process_one_work+0x165/0x410 [ 6984.857475] worker_thread+0x137/0x4c0 [ 6984.857478] kthread+0x101/0x140 [ 6984.857480] ? rescuer_thread+0x3b0/0x3b0 [ 6984.857481] ? kthread_park+0x90/0x90 [ 6984.857489] ret_from_fork+0x2c/0x40 [ 6984.857490] Code: 8b bd 70 ff ff ff 89 95 50 ff ff ff 89 8d 58 ff ff ff 44 89 95 60 ff ff ff e8 b7 dd 12 e1 8b 95 50 ff ff ff 48 89 85 68 ff ff ff <4c> 8b 48 10 44 8b 58 18 8b 8d 58 ff ff ff 44 8b 95 60 ff ff ff [ 6984.857511] RIP: nvme_queue_rq+0x6e6/0x8cd [nvme] RSP: ffffc90002e93c50 [ 6984.857512] CR2: 0000000000000010 [ 6984.895359] ---[ end trace 2d7ceb528432bf83 ]--- Reported-by: Yi Zhang <[email protected]> Tested-by: Yi Zhang <[email protected]> Reviewed-by: Bart Van Assche <[email protected]> Reviewed-by: Hannes Reinecke <[email protected]> Signed-off-by: Ming Lei <[email protected]> Signed-off-by: Jens Axboe <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>

[ Upstream commit 6bb47e8 ] Memory leak and unbalanced reference count: If the hub gets disconnected while the core is still activating it, this can result in leaking memory of few USB structures. This will happen if we have done a kref_get() from hub_activate() and scheduled a delayed work item for HUB_INIT2/3. Now if hub_disconnect() gets called before the delayed work expires, then we will cancel the work from hub_quiesce(), but wouldn't do a kref_put(). And so the unbalance. kmemleak reports this as (with the commit e50293e backported to 3.10 kernel with other changes, though the same is true for mainline as well): unreferenced object 0xffffffc08af5b800 (size 1024): comm "khubd", pid 73, jiffies 4295051211 (age 6482.350s) hex dump (first 32 bytes): 30 68 f3 8c c0 ff ff ff 00 a0 b2 2e c0 ff ff ff 0h.............. 01 00 00 00 00 00 00 00 00 94 7d 40 c0 ff ff ff ..........}@.... backtrace: [<ffffffc0003079ec>] create_object+0x148/0x2a0 [<ffffffc000cc150c>] kmemleak_alloc+0x80/0xbc [<ffffffc000303a7c>] kmem_cache_alloc_trace+0x120/0x1ac [<ffffffc0006fa610>] hub_probe+0x120/0xb84 [<ffffffc000702b20>] usb_probe_interface+0x1ec/0x298 [<ffffffc0005d50cc>] driver_probe_device+0x160/0x374 [<ffffffc0005d5308>] __device_attach+0x28/0x4c [<ffffffc0005d3164>] bus_for_each_drv+0x78/0xac [<ffffffc0005d4ee0>] device_attach+0x6c/0x9c [<ffffffc0005d42b8>] bus_probe_device+0x28/0xa0 [<ffffffc0005d23a4>] device_add+0x324/0x604 [<ffffffc000700fcc>] usb_set_configuration+0x660/0x6cc [<ffffffc00070a350>] generic_probe+0x44/0x84 [<ffffffc000702914>] usb_probe_device+0x54/0x74 [<ffffffc0005d50cc>] driver_probe_device+0x160/0x374 [<ffffffc0005d5308>] __device_attach+0x28/0x4c Deadlocks: If the hub gets disconnected early enough (i.e. before INIT2/INIT3 are finished and the init_work is still queued), the core may call hub_quiesce() after acquiring interface device locks and it will wait for the work to be cancelled synchronously. But if the work handler is already running in parallel, it may try to acquire the same interface device lock and this may result in deadlock. Fix both the issues by removing the call to cancel_delayed_work_sync(). CC: <[email protected]> #4.4+ Fixes: e50293e ("USB: fix invalid memory access in hub_activate()") Reported-by: Manu Gautam <[email protected]> Signed-off-by: Viresh Kumar <[email protected]> Acked-by: Alan Stern <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> Signed-off-by: Sasha Levin <[email protected]>

commit d5afb6f upstream. The code where sk_clone() came from created a new socket and locked it, but then, on the error path didn't unlock it. This problem stayed there for a long while, till b0691c8 ("net: Unlock sock before calling sk_free()") fixed it, but unfortunately the callers of sk_clone() (now sk_clone_locked()) were not audited and the one in dccp_create_openreq_child() remained. Now in the age of the syskaller fuzzer, this was finally uncovered, as reported by Dmitry: ---- 8< ---- I've got the following report while running syzkaller fuzzer on 86292b3 ("Merge branch 'akpm' (patches from Andrew)") [ BUG: held lock freed! ] 4.10.0+ torvalds#234 Not tainted ------------------------- syz-executor6/6898 is freeing memory ffff88006286cac0-ffff88006286d3b7, with a lock still held there! (slock-AF_INET6){+.-...}, at: [<ffffffff8362c2c9>] spin_lock include/linux/spinlock.h:299 [inline] (slock-AF_INET6){+.-...}, at: [<ffffffff8362c2c9>] sk_clone_lock+0x3d9/0x12c0 net/core/sock.c:1504 5 locks held by syz-executor6/6898: #0: (sk_lock-AF_INET6){+.+.+.}, at: [<ffffffff839a34b4>] lock_sock include/net/sock.h:1460 [inline] #0: (sk_lock-AF_INET6){+.+.+.}, at: [<ffffffff839a34b4>] inet_stream_connect+0x44/0xa0 net/ipv4/af_inet.c:681 #1: (rcu_read_lock){......}, at: [<ffffffff83bc1c2a>] inet6_csk_xmit+0x12a/0x5d0 net/ipv6/inet6_connection_sock.c:126 #2: (rcu_read_lock){......}, at: [<ffffffff8369b424>] __skb_unlink include/linux/skbuff.h:1767 [inline] #2: (rcu_read_lock){......}, at: [<ffffffff8369b424>] __skb_dequeue include/linux/skbuff.h:1783 [inline] #2: (rcu_read_lock){......}, at: [<ffffffff8369b424>] process_backlog+0x264/0x730 net/core/dev.c:4835 #3: (rcu_read_lock){......}, at: [<ffffffff83aeb5c0>] ip6_input_finish+0x0/0x1700 net/ipv6/ip6_input.c:59 #4: (slock-AF_INET6){+.-...}, at: [<ffffffff8362c2c9>] spin_lock include/linux/spinlock.h:299 [inline] #4: (slock-AF_INET6){+.-...}, at: [<ffffffff8362c2c9>] sk_clone_lock+0x3d9/0x12c0 net/core/sock.c:1504 Fix it just like was done by b0691c8 ("net: Unlock sock before calling sk_free()"). Reported-by: Dmitry Vyukov <[email protected]> Cc: Cong Wang <[email protected]> Cc: Eric Dumazet <[email protected]> Cc: Gerrit Renker <[email protected]> Cc: Thomas Gleixner <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>

commit 69307cc upstream. As per [1] issue open-power-host-os#4, "The periodic EP scheduler always tries to schedule the EPs that have large intervals (interval equal to or greater than 128 microframes) into different microframes. So it maintains an internal counter and increments for each large interval EP added. When the counter is greater than 128, the scheduler rejects the new EP. So when the hub re-enumerated 128 times, it triggers this condition." This results in Bandwidth error when devices with periodic endpoints (ISO/INT) having bInterval > 7 are plugged and unplugged several times on a TUSB73x0 XHCI host. Workaround this issue by limiting the bInterval to 7 (i.e. interval to 6) for High-speed or faster periodic endpoints. [1] - http://www.ti.com/lit/er/sllz076/sllz076.pdf Signed-off-by: Roger Quadros <[email protected]> Signed-off-by: Mathias Nyman <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>

commit cdea465 upstream. A vendor with a system having more than 128 CPUs occasionally encounters the following crash during shutdown. This is not an easily reproduceable event, but the vendor was able to provide the following analysis of the crash, which exhibits the same footprint each time. crash> bt PID: 0 TASK: ffff88017c70ce70 CPU: 5 COMMAND: "swapper/5" #0 [ffff88085c143ac8] machine_kexec at ffffffff81059c8b #1 [ffff88085c143b28] __crash_kexec at ffffffff811052e2 open-power-host-os#2 [ffff88085c143bf8] crash_kexec at ffffffff811053d0 open-power-host-os#3 [ffff88085c143c10] oops_end at ffffffff8168ef88 open-power-host-os#4 [ffff88085c143c38] no_context at ffffffff8167ebb3 open-power-host-os#5 [ffff88085c143c88] __bad_area_nosemaphore at ffffffff8167ec49 open-power-host-os#6 [ffff88085c143cd0] bad_area_nosemaphore at ffffffff8167edb3 open-power-host-os#7 [ffff88085c143ce0] __do_page_fault at ffffffff81691d1e open-power-host-os#8 [ffff88085c143d40] do_page_fault at ffffffff81691ec5 open-power-host-os#9 [ffff88085c143d70] page_fault at ffffffff8168e188 [exception RIP: unknown or invalid address] RIP: ffffffffa053c800 RSP: ffff88085c143e28 RFLAGS: 00010206 RAX: ffff88017c72bfd8 RBX: ffff88017a8dc000 RCX: ffff8810588b5ac8 RDX: ffff8810588b5a00 RSI: ffffffffa053c800 RDI: ffff8810588b5a00 RBP: ffff88085c143e58 R8: ffff88017c70d408 R9: ffff88017a8dc000 R10: 0000000000000002 R11: ffff88085c143da0 R12: ffff8810588b5ac8 R13: 0000000000000100 R14: ffffffffa053c800 R15: ffff8810588b5a00 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 <IRQ stack> [exception RIP: cpuidle_enter_state+82] RIP: ffffffff81514192 RSP: ffff88017c72be50 RFLAGS: 00000202 RAX: 0000001e4c3c6f16 RBX: 000000000000f8a0 RCX: 0000000000000018 RDX: 0000000225c17d03 RSI: ffff88017c72bfd8 RDI: 0000001e4c3c6f16 RBP: ffff88017c72be78 R8: 000000000000237e R9: 0000000000000018 R10: 0000000000002494 R11: 0000000000000001 R12: ffff88017c72be20 R13: ffff88085c14f8e0 R14: 0000000000000082 R15: 0000001e4c3bb400 ORIG_RAX: ffffffffffffff10 CS: 0010 SS: 0018 This is the corresponding stack trace It has crashed because the area pointed with RIP extracted from timer element is already removed during a shutdown process. The function is smi_timeout(). And we think ffff8810588b5a00 in RDX is a parameter struct smi_info crash> rd ffff8810588b5a00 20 ffff8810588b5a00: ffff8810588b6000 0000000000000000 .`.X............ ffff8810588b5a10: ffff880853264400 ffffffffa05417e0 .D&S......T..... ffff8810588b5a20: 24a024a000000000 0000000000000000 .....$.$........ ffff8810588b5a30: 0000000000000000 0000000000000000 ................ ffff8810588b5a30: 0000000000000000 0000000000000000 ................ ffff8810588b5a40: ffffffffa053a040 ffffffffa053a060 @.S.....`.S..... ffff8810588b5a50: 0000000000000000 0000000100000001 ................ ffff8810588b5a60: 0000000000000000 0000000000000e00 ................ ffff8810588b5a70: ffffffffa053a580 ffffffffa053a6e0 ..S.......S..... ffff8810588b5a80: ffffffffa053a4a0 ffffffffa053a250 ..S.....P.S..... ffff8810588b5a90: 0000000500000002 0000000000000000 ................ Unfortunately the top of this area is already detroyed by someone. But because of two reasonns we think this is struct smi_info 1) The address included in between ffff8810588b5a70 and ffff8810588b5a80: are inside of ipmi_si_intf.c see crash> module ffff88085779d2c0 2) We've found the area which point this. It is offset 0x68 of ffff880859df4000 crash> rd ffff880859df4000 100 ffff880859df4000: 0000000000000000 0000000000000001 ................ ffff880859df4010: ffffffffa0535290 dead000000000200 .RS............. ffff880859df4020: ffff880859df4020 ffff880859df4020 @.Y.... @.Y.... ffff880859df4030: 0000000000000002 0000000000100010 ................ ffff880859df4040: ffff880859df4040 ffff880859df4040 @@.Y....@@.Y.... ffff880859df4050: 0000000000000000 0000000000000000 ................ ffff880859df4060: 0000000000000000 ffff8810588b5a00 .........Z.X.... ffff880859df4070: 0000000000000001 ffff880859df4078 [email protected].... If we regards it as struct ipmi_smi in shutdown process it looks consistent. The remedy for this apparent race is affixed below. Signed-off-by: Tony Camuso <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> This was first introduced in 7ea0ed2 ipmi: Make the message handler easier to use for SMI interfaces where some code was moved outside of the rcu_read_lock() and the lock was not added. Signed-off-by: Corey Minyard <[email protected]>

… crash commit 96b7774 upstream. Commit: 2f5177f ("sched/cgroup: Fix/cleanup cgroup teardown/init") .. moved sched_online_group() from css_online() to css_alloc(). It exposes half-baked task group into global lists before initializing generic cgroup stuff. LTP testcase (third in cgroup_regression_test) written for testing similar race in kernels 2.6.26-2.6.28 easily triggers this oops: BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 IP: kernfs_path_from_node_locked+0x260/0x320 CPU: 1 PID: 30346 Comm: cat Not tainted 4.10.0-rc5-test open-power-host-os#4 Call Trace: ? kernfs_path_from_node+0x4f/0x60 kernfs_path_from_node+0x3e/0x60 print_rt_rq+0x44/0x2b0 print_rt_stats+0x7a/0xd0 print_cpu+0x2fc/0xe80 ? __might_sleep+0x4a/0x80 sched_debug_show+0x17/0x30 seq_read+0xf2/0x3b0 proc_reg_read+0x42/0x70 __vfs_read+0x28/0x130 ? security_file_permission+0x9b/0xc0 ? rw_verify_area+0x4e/0xb0 vfs_read+0xa5/0x170 SyS_read+0x46/0xa0 entry_SYSCALL_64_fastpath+0x1e/0xad Here the task group is already linked into the global RCU-protected 'task_groups' list, but the css->cgroup pointer is still NULL. This patch reverts this chunk and moves online back to css_online(). Signed-off-by: Konstantin Khlebnikov <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Tejun Heo <[email protected]> Cc: Thomas Gleixner <[email protected]> Fixes: 2f5177f ("sched/cgroup: Fix/cleanup cgroup teardown/init") Link: http://lkml.kernel.org/r/148655324740.424917.5302984537258726349.stgit@buzz Signed-off-by: Ingo Molnar <[email protected]> Signed-off-by: Matt Fleming <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>

commit 89affbf upstream. In codepaths that use the begin/retry interface for reading mems_allowed_seq with irqs disabled, there exists a race condition that stalls the patch process after only modifying a subset of the static_branch call sites. This problem manifested itself as a deadlock in the slub allocator, inside get_any_partial. The loop reads mems_allowed_seq value (via read_mems_allowed_begin), performs the defrag operation, and then verifies the consistency of mem_allowed via the read_mems_allowed_retry and the cookie returned by xxx_begin. The issue here is that both begin and retry first check if cpusets are enabled via cpusets_enabled() static branch. This branch can be rewritted dynamically (via cpuset_inc) if a new cpuset is created. The x86 jump label code fully synchronizes across all CPUs for every entry it rewrites. If it rewrites only one of the callsites (specifically the one in read_mems_allowed_retry) and then waits for the smp_call_function(do_sync_core) to complete while a CPU is inside the begin/retry section with IRQs off and the mems_allowed value is changed, we can hang. This is because begin() will always return 0 (since it wasn't patched yet) while retry() will test the 0 against the actual value of the seq counter. The fix is to use two different static keys: one for begin (pre_enable_key) and one for retry (enable_key). In cpuset_inc(), we first bump the pre_enable key to ensure that cpuset_mems_allowed_begin() always return a valid seqcount if are enabling cpusets. Similarly, when disabling cpusets via cpuset_dec(), we first ensure that callers of cpuset_mems_allowed_retry() will start ignoring the seqcount value before we let cpuset_mems_allowed_begin() return 0. The relevant stack traces of the two stuck threads: CPU: 1 PID: 1415 Comm: mkdir Tainted: G L 4.9.36-00104-g540c51286237 open-power-host-os#4 Hardware name: Default string Default string/Hardware, BIOS 4.29.1-20170526215256 05/26/2017 task: ffff8817f9c28000 task.stack: ffffc9000ffa4000 RIP: smp_call_function_many+0x1f9/0x260 Call Trace: smp_call_function+0x3b/0x70 on_each_cpu+0x2f/0x90 text_poke_bp+0x87/0xd0 arch_jump_label_transform+0x93/0x100 __jump_label_update+0x77/0x90 jump_label_update+0xaa/0xc0 static_key_slow_inc+0x9e/0xb0 cpuset_css_online+0x70/0x2e0 online_css+0x2c/0xa0 cgroup_apply_control_enable+0x27f/0x3d0 cgroup_mkdir+0x2b7/0x420 kernfs_iop_mkdir+0x5a/0x80 vfs_mkdir+0xf6/0x1a0 SyS_mkdir+0xb7/0xe0 entry_SYSCALL_64_fastpath+0x18/0xad ... CPU: 2 PID: 1 Comm: init Tainted: G L 4.9.36-00104-g540c51286237 open-power-host-os#4 Hardware name: Default string Default string/Hardware, BIOS 4.29.1-20170526215256 05/26/2017 task: ffff8818087c0000 task.stack: ffffc90000030000 RIP: int3+0x39/0x70 Call Trace: <#DB> ? ___slab_alloc+0x28b/0x5a0 <EOE> ? copy_process.part.40+0xf7/0x1de0 __slab_alloc.isra.80+0x54/0x90 copy_process.part.40+0xf7/0x1de0 copy_process.part.40+0xf7/0x1de0 kmem_cache_alloc_node+0x8a/0x280 copy_process.part.40+0xf7/0x1de0 _do_fork+0xe7/0x6c0 _raw_spin_unlock_irq+0x2d/0x60 trace_hardirqs_on_caller+0x136/0x1d0 entry_SYSCALL_64_fastpath+0x5/0xad do_syscall_64+0x27/0x350 SyS_clone+0x19/0x20 do_syscall_64+0x60/0x350 entry_SYSCALL64_slow_path+0x25/0x25 Link: http://lkml.kernel.org/r/[email protected] Fixes: 46e700a ("mm, page_alloc: remove unnecessary taking of a seqlock when cpusets are disabled") Signed-off-by: Dima Zavin <[email protected]> Reported-by: Cliff Spradlin <[email protected]> Acked-by: Vlastimil Babka <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Christopher Lameter <[email protected]> Cc: Li Zefan <[email protected]> Cc: Pekka Enberg <[email protected]> Cc: David Rientjes <[email protected]> Cc: Joonsoo Kim <[email protected]> Cc: Mel Gorman <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>

In codepaths that use the begin/retry interface for reading mems_allowed_seq with irqs disabled, there exists a race condition that stalls the patch process after only modifying a subset of the static_branch call sites. This problem manifested itself as a deadlock in the slub allocator, inside get_any_partial. The loop reads mems_allowed_seq value (via read_mems_allowed_begin), performs the defrag operation, and then verifies the consistency of mem_allowed via the read_mems_allowed_retry and the cookie returned by xxx_begin. The issue here is that both begin and retry first check if cpusets are enabled via cpusets_enabled() static branch. This branch can be rewritted dynamically (via cpuset_inc) if a new cpuset is created. The x86 jump label code fully synchronizes across all CPUs for every entry it rewrites. If it rewrites only one of the callsites (specifically the one in read_mems_allowed_retry) and then waits for the smp_call_function(do_sync_core) to complete while a CPU is inside the begin/retry section with IRQs off and the mems_allowed value is changed, we can hang. This is because begin() will always return 0 (since it wasn't patched yet) while retry() will test the 0 against the actual value of the seq counter. The fix is to use two different static keys: one for begin (pre_enable_key) and one for retry (enable_key). In cpuset_inc(), we first bump the pre_enable key to ensure that cpuset_mems_allowed_begin() always return a valid seqcount if are enabling cpusets. Similarly, when disabling cpusets via cpuset_dec(), we first ensure that callers of cpuset_mems_allowed_retry() will start ignoring the seqcount value before we let cpuset_mems_allowed_begin() return 0. The relevant stack traces of the two stuck threads: CPU: 1 PID: 1415 Comm: mkdir Tainted: G L 4.9.36-00104-g540c51286237 #4 Hardware name: Default string Default string/Hardware, BIOS 4.29.1-20170526215256 05/26/2017 task: ffff8817f9c28000 task.stack: ffffc9000ffa4000 RIP: smp_call_function_many+0x1f9/0x260 Call Trace: smp_call_function+0x3b/0x70 on_each_cpu+0x2f/0x90 text_poke_bp+0x87/0xd0 arch_jump_label_transform+0x93/0x100 __jump_label_update+0x77/0x90 jump_label_update+0xaa/0xc0 static_key_slow_inc+0x9e/0xb0 cpuset_css_online+0x70/0x2e0 online_css+0x2c/0xa0 cgroup_apply_control_enable+0x27f/0x3d0 cgroup_mkdir+0x2b7/0x420 kernfs_iop_mkdir+0x5a/0x80 vfs_mkdir+0xf6/0x1a0 SyS_mkdir+0xb7/0xe0 entry_SYSCALL_64_fastpath+0x18/0xad ... CPU: 2 PID: 1 Comm: init Tainted: G L 4.9.36-00104-g540c51286237 #4 Hardware name: Default string Default string/Hardware, BIOS 4.29.1-20170526215256 05/26/2017 task: ffff8818087c0000 task.stack: ffffc90000030000 RIP: int3+0x39/0x70 Call Trace: <#DB> ? ___slab_alloc+0x28b/0x5a0 <EOE> ? copy_process.part.40+0xf7/0x1de0 __slab_alloc.isra.80+0x54/0x90 copy_process.part.40+0xf7/0x1de0 copy_process.part.40+0xf7/0x1de0 kmem_cache_alloc_node+0x8a/0x280 copy_process.part.40+0xf7/0x1de0 _do_fork+0xe7/0x6c0 _raw_spin_unlock_irq+0x2d/0x60 trace_hardirqs_on_caller+0x136/0x1d0 entry_SYSCALL_64_fastpath+0x5/0xad do_syscall_64+0x27/0x350 SyS_clone+0x19/0x20 do_syscall_64+0x60/0x350 entry_SYSCALL64_slow_path+0x25/0x25 Link: http://lkml.kernel.org/r/[email protected] Fixes: 46e700a ("mm, page_alloc: remove unnecessary taking of a seqlock when cpusets are disabled") Signed-off-by: Dima Zavin <[email protected]> Reported-by: Cliff Spradlin <[email protected]> Acked-by: Vlastimil Babka <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Christopher Lameter <[email protected]> Cc: Li Zefan <[email protected]> Cc: Pekka Enberg <[email protected]> Cc: David Rientjes <[email protected]> Cc: Joonsoo Kim <[email protected]> Cc: Mel Gorman <[email protected]> Cc: <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>

c70c473 "ARCv2: SLC: Make sure busy bit is set properly on SLC flushing" fixes problem for entire SLC operation where the problem was initially caught. But given a nature of the issue it is perfectly possible for busy bit to be read incorrectly even when region operation was started. So extending initial fix for regional operation as well. Signed-off-by: Alexey Brodkin <[email protected]> Cc: [email protected] #4.10 Signed-off-by: Vineet Gupta <[email protected]>

It is necessary to explicitly set both SLC_AUX_RGN_START1 and SLC_AUX_RGN_END1 which hold MSB bits of the physical address correspondingly of region start and end otherwise SLC region operation is executed in unpredictable manner Without this patch, SLC flushes on HSDK (IOC disabled) were taking seconds. Cc: [email protected] #4.4+ Reported-by: Vladimir Kondratiev <[email protected]> Signed-off-by: Alexey Brodkin <[email protected]> Signed-off-by: Vineet Gupta <[email protected]> [vgupta: PAR40 regs only written if PAE40 exist]

… SoC PAE40 confiuration in hardware extends some of the address registers for TLB/cache ops to 2 words. So far kernel was NOT setting the higher word if feature was not enabled in software which is wrong. Those need to be set to 0 in such case. Normally this would be done in the cache flush / tlb ops, however since these registers only exist conditionally, this would have to be conditional to a flag being set on boot which is expensive/ugly - specially for the more common case of PAE exists but not in use. Optimize that by zero'ing them once at boot - nobody will write to them afterwards Cc: [email protected] #4.4+ Signed-off-by: Vineet Gupta <[email protected]>

We really must check with #if __BYTE_ORDER == XYZ instead of just presence of #ifdef __LITTLE_ENDIAN. I noticed that when actually running this on big endian machine, the latter test resolves to true for user space, same for #ifdef __BIG_ENDIAN. E.g., looking at endian.h from libc, both are also defined there, so we really must test this against __BYTE_ORDER instead for proper insns selection. For the kernel, such checks are fine though e.g. see 13da9e2 ("Revert "endian: #define __BYTE_ORDER"") and 415586c ("UAPI: fix endianness conditionals in M32R's asm/stat.h") for some more context, but not for user space. Lets also make sure to properly include endian.h. After that, suite passes for me: ./test_verifier: ELF 64-bit MSB executable, [...] Linux foo 4.13.0-rc3+ #4 SMP Fri Aug 4 06:59:30 EDT 2017 s390x s390x s390x GNU/Linux Before fix: Summary: 505 PASSED, 11 FAILED After fix: Summary: 516 PASSED, 0 FAILED Fixes: 18f3d6b ("selftests/bpf: Add test cases to test narrower ctx field loads") Signed-off-by: Daniel Borkmann <[email protected]> Acked-by: Yonghong <[email protected]> Signed-off-by: David S. Miller <[email protected]>

A relocation pointing to the last four bytes of a buffer can legitimately happen in the case of small vertex buffers. CC: [email protected] #4.9+ Signed-off-by: Wladimir J. van der Laan <[email protected]> Reviewed-by: Philipp Zabel <[email protected]> Reviewed-by: Christian Gmeiner <[email protected]> Signed-off-by: Lucas Stach <[email protected]>

…buffer Since we split the scsi_request out of struct request bsg fails to provide a reply-buffer for the drivers. This was done via the pointer for sense-data, that is not preallocated anymore. Failing to allocate/assign it results in illegal dereferences because LLDs use this pointer unquestioned. An example panic on s390x, using the zFCP driver, looks like this (I had debugging on, otherwise NULL-pointer dereferences wouldn't even panic on s390x): Unable to handle kernel pointer dereference in virtual kernel address space Failing address: 6b6b6b6b6b6b6000 TEID: 6b6b6b6b6b6b6403 Fault in home space mode while using kernel ASCE. AS:0000000001590007 R3:0000000000000024 Oops: 0038 ilc:2 [#1] PREEMPT SMP DEBUG_PAGEALLOC Modules linked in: <Long List> CPU: 2 PID: 0 Comm: swapper/2 Not tainted 4.12.0-bsg-regression+ #3 Hardware name: IBM 2964 N96 702 (z/VM 6.4.0) task: 0000000065cb0100 task.stack: 0000000065cb4000 Krnl PSW : 0704e00180000000 000003ff801e4156 (zfcp_fc_ct_els_job_handler+0x16/0x58 [zfcp]) R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:2 PM:0 RI:0 EA:3 Krnl GPRS: 0000000000000001 000000005fa9d0d0 000000005fa9d078 0000000000e16866 000003ff00000290 6b6b6b6b6b6b6b6b 0000000059f78f00 000000000000000f 00000000593a0958 00000000593a0958 0000000060d88800 000000005ddd4c38 0000000058b50100 07000000659cba08 000003ff801e8556 00000000659cb9a8 Krnl Code: 000003ff801e4146: e31020500004 lg %r1,80(%r2) 000003ff801e414c: 58402040 l %r4,64(%r2) #000003ff801e4150: e35020200004 lg %r5,32(%r2) >000003ff801e4156: 50405004 st %r4,4(%r5) 000003ff801e415a: e54c50080000 mvhi 8(%r5),0 000003ff801e4160: e33010280012 lt %r3,40(%r1) 000003ff801e4166: a718fffb lhi %r1,-5 000003ff801e416a: 1803 lr %r0,%r3 Call Trace: ([<000003ff801e8556>] zfcp_fsf_req_complete+0x726/0x768 [zfcp]) [<000003ff801ea82a>] zfcp_fsf_reqid_check+0x102/0x180 [zfcp] [<000003ff801eb980>] zfcp_qdio_int_resp+0x230/0x278 [zfcp] [<00000000009b91b6>] qdio_kick_handler+0x2ae/0x2c8 [<00000000009b9e3e>] __tiqdio_inbound_processing+0x406/0xc10 [<00000000001684c2>] tasklet_action+0x15a/0x1d8 [<0000000000bd28ec>] __do_softirq+0x3ec/0x848 [<00000000001675a4>] irq_exit+0x74/0xf8 [<000000000010dd6a>] do_IRQ+0xba/0xf0 [<0000000000bd19e8>] io_int_handler+0x104/0x2d4 [<00000000001033b6>] enabled_wait+0xb6/0x188 ([<000000000010339e>] enabled_wait+0x9e/0x188) [<000000000010396a>] arch_cpu_idle+0x32/0x50 [<0000000000bd0112>] default_idle_call+0x52/0x68 [<00000000001cd0fa>] do_idle+0x102/0x188 [<00000000001cd41e>] cpu_startup_entry+0x3e/0x48 [<0000000000118c64>] smp_start_secondary+0x11c/0x130 [<0000000000bd2016>] restart_int_handler+0x62/0x78 [<0000000000000000>] (null) INFO: lockdep is turned off. Last Breaking-Event-Address: [<000003ff801e41d6>] zfcp_fc_ct_job_handler+0x3e/0x48 [zfcp] Kernel panic - not syncing: Fatal exception in interrupt This patch moves bsg-lib to allocate and setup struct bsg_job ahead of time, including the allocation of a buffer for the reply-data. This means, struct bsg_job is not allocated separately anymore, but as part of struct request allocation - similar to struct scsi_cmd. Reflect this in the function names that used to handle creation/destruction of struct bsg_job. Reported-by: Steffen Maier <[email protected]> Suggested-by: Christoph Hellwig <[email protected]> Reviewed-by: Christoph Hellwig <[email protected]> Signed-off-by: Benjamin Block <[email protected]> Fixes: 82ed4db ("block: split scsi_request out of struct request") Cc: <[email protected]> #4.11+ Signed-off-by: Jens Axboe <[email protected]>

This patch fixes a regression caused by the new changes in the "run wake" handlers. The mei devices that support D0i3 are no longer receiving an interrupt after entering runtime suspend state and will stall. pci_dev_run_wake function now returns "true" for some devices (including mei) for which it used to return "false", arguably incorrectly as "run wake" used to mean that wakeup signals can be generated for a device in the working state of the system, so it could not be enabled or disabled before too. MEI maps runtime suspend/resume to its own defined power gating (PG) states, (D0i3 or other depending on generation), hence we need to go around the native PCI runtime service which eventually brings the device into D3cold/hot state, but the mei devices cannot wake up from D3 unlike from D0i3/PG state, which keeps irq running. To get around PCI device native runtime pm, MEI uses runtime pm domain handlers which take precedence. Cc: <[email protected]> #4.13+ Signed-off-by: Alexander Usyskin <[email protected]> Signed-off-by: Tomas Winkler <[email protected]> Acked-by: Rafael J. Wysocki <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>

ppp_release() tries to ensure that netdevices are unregistered before decrementing the unit refcount and running ppp_destroy_interface(). This is all fine as long as the the device is unregistered by ppp_release(): the unregister_netdevice() call, followed by rtnl_unlock(), guarantee that the unregistration process completes before rtnl_unlock() returns. However, the device may be unregistered by other means (like ppp_nl_dellink()). If this happens right before ppp_release() calling rtnl_lock(), then ppp_release() has to wait for the concurrent unregistration code to release the lock. But rtnl_unlock() releases the lock before completing the device unregistration process. This allows ppp_release() to proceed and eventually call ppp_destroy_interface() before the unregistration process completes. Calling free_netdev() on this partially unregistered device will BUG(): ------------[ cut here ]------------ kernel BUG at net/core/dev.c:8141! invalid opcode: 0000 [#1] SMP CPU: 1 PID: 1557 Comm: pppd Not tainted 4.14.0-rc2+ #4 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1.fc26 04/01/2014 Call Trace: ppp_destroy_interface+0xd8/0xe0 [ppp_generic] ppp_disconnect_channel+0xda/0x110 [ppp_generic] ppp_unregister_channel+0x5e/0x110 [ppp_generic] pppox_unbind_sock+0x23/0x30 [pppox] pppoe_connect+0x130/0x440 [pppoe] SYSC_connect+0x98/0x110 ? do_fcntl+0x2c0/0x5d0 SyS_connect+0xe/0x10 entry_SYSCALL_64_fastpath+0x1a/0xa5 RIP: free_netdev+0x107/0x110 RSP: ffffc28a40573d88 ---[ end trace ed294ff0cc40eeff ]--- We could set the ->needs_free_netdev flag on PPP devices and move the ppp_destroy_interface() logic in the ->priv_destructor() callback. But that'd be quite intrusive as we'd first need to unlink from the other channels and units that depend on the device (the ones that used the PPPIOCCONNECT and PPPIOCATTACH ioctls). Instead, we can just let the netdevice hold a reference on its ppp_file. This reference is dropped in ->priv_destructor(), at the very end of the unregistration process, so that neither ppp_release() nor ppp_disconnect_channel() can call ppp_destroy_interface() in the interim. Reported-by: Beniamino Galvani <[email protected]> Fixes: 8cb775b ("ppp: fix device unregistration upon netns deletion") Signed-off-by: Guillaume Nault <[email protected]> Signed-off-by: David S. Miller <[email protected]>

v4.10 commit 6f2ce1c ("scsi: zfcp: fix rport unblock race with LUN recovery") extended accessing parent pointer fields of struct zfcp_erp_action for tracing. If an erp_action has never been enqueued before, these parent pointer fields are uninitialized and NULL. Examples are zfcp objects freshly added to the parent object's children list, before enqueueing their first recovery subsequently. In zfcp_erp_try_rport_unblock(), we iterate such list. Accessing erp_action fields can cause a NULL pointer dereference. Since the kernel can read from lowcore on s390, it does not immediately cause a kernel page fault. Instead it can cause hangs on trying to acquire the wrong erp_action->adapter->dbf->rec_lock in zfcp_dbf_rec_action_lvl() ^bogus^ while holding already other locks with IRQs disabled. Real life example from attaching lots of LUNs in parallel on many CPUs: crash> bt 17723 PID: 17723 TASK: ... CPU: 25 COMMAND: "zfcperp0.0.1800" LOWCORE INFO: -psw : 0x0404300180000000 0x000000000038e424 -function : _raw_spin_lock_wait_flags at 38e424 ... #0 [fdde8fc90] zfcp_dbf_rec_action_lvl at 3e0004e9862 [zfcp] #1 [fdde8fce8] zfcp_erp_try_rport_unblock at 3e0004dfddc [zfcp] #2 [fdde8fd38] zfcp_erp_strategy at 3e0004e0234 [zfcp] #3 [fdde8fda8] zfcp_erp_thread at 3e0004e0a12 [zfcp] #4 [fdde8fe60] kthread at 173550 #5 [fdde8feb8] kernel_thread_starter at 10add2 zfcp_adapter zfcp_port zfcp_unit <address>, 0x404040d600000000 scsi_device NULL, returning early! zfcp_scsi_dev.status = 0x40000000 0x40000000 ZFCP_STATUS_COMMON_RUNNING crash> zfcp_unit <address> struct zfcp_unit { erp_action = { adapter = 0x0, port = 0x0, unit = 0x0, }, } zfcp_erp_action is always fully embedded into its container object. Such container object is never moved in its object tree (only add or delete). Hence, erp_action parent pointers can never change. To fix the issue, initialize the erp_action parent pointers before adding the erp_action container to any list and thus before it becomes accessible from outside of its initializing function. In order to also close the time window between zfcp_erp_setup_act() memsetting the entire erp_action to zero and setting the parent pointers again, drop the memset and instead explicitly initialize individually all erp_action fields except for parent pointers. To be extra careful not to introduce any other unintended side effect, even keep zeroing the erp_action fields for list and timer. Also double-check with WARN_ON_ONCE that erp_action parent pointers never change, so we get to know when we would deviate from previous behavior. Signed-off-by: Steffen Maier <[email protected]> Fixes: 6f2ce1c ("scsi: zfcp: fix rport unblock race with LUN recovery") Cc: <[email protected]> #2.6.32+ Reviewed-by: Benjamin Block <[email protected]> Signed-off-by: Martin K. Petersen <[email protected]>

Thomas reported that 'perf buildid-list' gets a SEGFAULT due to NULL pointer deref when he ran it on a data with namespace events. It was because the buildid_id__mark_dso_hit_ops lacks the namespace event handler and perf_too__fill_default() didn't set it. Program received signal SIGSEGV, Segmentation fault. 0x0000000000000000 in ?? () Missing separate debuginfos, use: dnf debuginfo-install audit-libs-2.7.7-1.fc25.s390x bzip2-libs-1.0.6-21.fc25.s390x elfutils-libelf-0.169-1.fc25.s390x +elfutils-libs-0.169-1.fc25.s390x libcap-ng-0.7.8-1.fc25.s390x numactl-libs-2.0.11-2.ibm.fc25.s390x openssl-libs-1.1.0e-1.1.ibm.fc25.s390x perl-libs-5.24.1-386.fc25.s390x +python-libs-2.7.13-2.fc25.s390x slang-2.3.0-7.fc25.s390x xz-libs-5.2.3-2.fc25.s390x zlib-1.2.8-10.fc25.s390x (gdb) where #0 0x0000000000000000 in ?? () #1 0x00000000010fad6a in machines__deliver_event (machines=<optimized out>, machines@entry=0x2c6fd18, evlist=<optimized out>, event=event@entry=0x3fffdf00470, sample=0x3ffffffe880, sample@entry=0x3ffffffe888, tool=tool@entry=0x1312968 <build_id.mark_dso_hit_ops>, file_offset=1136) at util/session.c:1287 #2 0x00000000010fbf4e in perf_session__deliver_event (file_offset=1136, tool=0x1312968 <build_id.mark_dso_hit_ops>, sample=0x3ffffffe888, event=0x3fffdf00470, session=0x2c6fc30) at util/session.c:1340 #3 perf_session__process_event (session=0x2c6fc30, session@entry=0x0, event=event@entry=0x3fffdf00470, file_offset=file_offset@entry=1136) at util/session.c:1522 #4 0x00000000010fddde in __perf_session__process_events (file_size=11880, data_size=<optimized out>, data_offset=<optimized out>, session=0x0) at util/session.c:1899 #5 perf_session__process_events (session=0x0, session@entry=0x2c6fc30) at util/session.c:1953 #6 0x000000000103b2ac in perf_session__list_build_ids (with_hits=<optimized out>, force=<optimized out>) at builtin-buildid-list.c:83 #7 cmd_buildid_list (argc=<optimized out>, argv=<optimized out>) at builtin-buildid-list.c:115 #8 0x00000000010a026c in run_builtin (p=0x1311f78 <commands+24>, argc=argc@entry=2, argv=argv@entry=0x3fffffff3c0) at perf.c:296 #9 0x000000000102bc00 in handle_internal_command (argv=<optimized out>, argc=2) at perf.c:348 #10 run_argv (argcp=<synthetic pointer>, argv=<synthetic pointer>) at perf.c:392 #11 main (argc=<optimized out>, argv=0x3fffffff3c0) at perf.c:536 (gdb) Fix it by adding a stub event handler for namespace event. Committer testing: Further clarifying, plain using 'perf buildid-list' will not end up in a SEGFAULT when processing a perf.data file with namespace info: # perf record -a --namespaces sleep 1 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 2.024 MB perf.data (1058 samples) ] # perf buildid-list | wc -l 38 # perf buildid-list | head -5 e2a171c7b905826fc8494f0711ba76ab6abbd604 /lib/modules/4.14.0-rc3+/build/vmlinux 874840a02d8f8a31cedd605d0b8653145472ced3 /lib/modules/4.14.0-rc3+/kernel/arch/x86/kvm/kvm-intel.ko ea7223776730cd8a22f320040aae4d54312984bc /lib/modules/4.14.0-rc3+/kernel/drivers/gpu/drm/i915/i915.ko 5961535e6732a8edb7f22b3f148bb2fa2e0be4b9 /lib/modules/4.14.0-rc3+/kernel/drivers/gpu/drm/drm.ko f045f54aa78cf1931cc893f78b6cbc52c72a8cb1 /usr/lib64/libc-2.25.so # It is only when one asks for checking what of those entries actually had samples, i.e. when we use either -H or --with-hits, that we will process all the PERF_RECORD_ events, and since tools/perf/builtin-buildid-list.c neither explicitely set a perf_tool.namespaces() callback nor the default stub was set that we end up, when processing a PERF_RECORD_NAMESPACE record, causing a SEGFAULT: # perf buildid-list -H Segmentation fault (core dumped) ^C # Reported-and-Tested-by: Thomas-Mich Richter <[email protected]> Signed-off-by: Namhyung Kim <[email protected]> Tested-by: Arnaldo Carvalho de Melo <[email protected]> Cc: Hari Bathini <[email protected]> Cc: Hendrik Brueckner <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas-Mich Richter <[email protected]> Fixes: f3b3614 ("perf tools: Add PERF_RECORD_NAMESPACES to include namespaces related info") Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

When an EMAD is transmitted, a timeout work item is scheduled with a delay of 200ms, so that another EMAD will be retried until a maximum of five retries. In certain situations, it's possible for the function waiting on the EMAD to be associated with a work item that is queued on the same workqueue (`mlxsw_core`) as the timeout work item. This results in flushing a work item on the same workqueue. According to commit e159489 ("workqueue: relax lockdep annotation on flush_work()") the above may lead to a deadlock in case the workqueue has only one worker active or if the system in under memory pressure and the rescue worker is in use. The latter explains the very rare and random nature of the lockdep splats we have been seeing: [ 52.730240] ============================================ [ 52.736179] WARNING: possible recursive locking detected [ 52.742119] 4.14.0-rc3jiri+ #4 Not tainted [ 52.746697] -------------------------------------------- [ 52.752635] kworker/1:3/599 is trying to acquire lock: [ 52.758378] (mlxsw_core_driver_name){+.+.}, at: [<ffffffff811c4fa4>] flush_work+0x3a4/0x5e0 [ 52.767837] but task is already holding lock: [ 52.774360] (mlxsw_core_driver_name){+.+.}, at: [<ffffffff811c65c4>] process_one_work+0x7d4/0x12f0 [ 52.784495] other info that might help us debug this: [ 52.791794] Possible unsafe locking scenario: [ 52.798413] CPU0 [ 52.801144] ---- [ 52.803875] lock(mlxsw_core_driver_name); [ 52.808556] lock(mlxsw_core_driver_name); [ 52.813236] *** DEADLOCK *** [ 52.819857] May be due to missing lock nesting notation [ 52.827450] 3 locks held by kworker/1:3/599: [ 52.832221] #0: (mlxsw_core_driver_name){+.+.}, at: [<ffffffff811c65c4>] process_one_work+0x7d4/0x12f0 [ 52.842846] #1: ((&(&bridge->fdb_notify.dw)->work)){+.+.}, at: [<ffffffff811c65c4>] process_one_work+0x7d4/0x12f0 [ 52.854537] #2: (rtnl_mutex){+.+.}, at: [<ffffffff822ad8e7>] rtnl_lock+0x17/0x20 [ 52.863021] stack backtrace: [ 52.867890] CPU: 1 PID: 599 Comm: kworker/1:3 Not tainted 4.14.0-rc3jiri+ #4 [ 52.875773] Hardware name: Mellanox Technologies Ltd. "MSN2100-CB2F"/"SA001017", BIOS 5.6.5 06/07/2016 [ 52.886267] Workqueue: mlxsw_core mlxsw_sp_fdb_notify_work [mlxsw_spectrum] [ 52.894060] Call Trace: [ 52.909122] __lock_acquire+0xf6f/0x2a10 [ 53.025412] lock_acquire+0x158/0x440 [ 53.047557] flush_work+0x3c4/0x5e0 [ 53.087571] __cancel_work_timer+0x3ca/0x5e0 [ 53.177051] cancel_delayed_work_sync+0x13/0x20 [ 53.182142] mlxsw_reg_trans_bulk_wait+0x12d/0x7a0 [mlxsw_core] [ 53.194571] mlxsw_core_reg_access+0x586/0x990 [mlxsw_core] [ 53.225365] mlxsw_reg_query+0x10/0x20 [mlxsw_core] [ 53.230882] mlxsw_sp_fdb_notify_work+0x2a3/0x9d0 [mlxsw_spectrum] [ 53.237801] process_one_work+0x8f1/0x12f0 [ 53.321804] worker_thread+0x1fd/0x10c0 [ 53.435158] kthread+0x28e/0x370 [ 53.448703] ret_from_fork+0x2a/0x40 [ 53.453017] mlxsw_spectrum 0000:01:00.0: EMAD retries (2/5) (tid=bf4549b100000774) [ 53.453119] mlxsw_spectrum 0000:01:00.0: EMAD retries (5/5) (tid=bf4549b100000770) [ 53.453132] mlxsw_spectrum 0000:01:00.0: EMAD reg access failed (tid=bf4549b100000770,reg_id=200b(sfn),type=query,status=0(operation performed)) [ 53.453143] mlxsw_spectrum 0000:01:00.0: Failed to get FDB notifications Fix this by creating another workqueue for EMAD timeouts, thereby preventing the situation of a work item trying to flush a work item queued on the same workqueue. Fixes: caf7297 ("mlxsw: core: Introduce support for asynchronous EMAD register access") Signed-off-by: Ido Schimmel <[email protected]> Reported-by: Jiri Pirko <[email protected]> Signed-off-by: Jiri Pirko <[email protected]> Signed-off-by: David S. Miller <[email protected]>

The warning below says it all: BUG: using __this_cpu_read() in preemptible [00000000] code: swapper/0/1 caller is __this_cpu_preempt_check CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.14.0-rc8 #4 Call Trace: dump_stack check_preemption_disabled ? do_early_param __this_cpu_preempt_check arch_perfmon_init op_nmi_init ? alloc_pci_root_info oprofile_arch_init oprofile_init do_one_initcall ... These accessors should not have been used in the first place: it is PPro so no mixed silicon revisions and thus it can simply use boot_cpu_data. Reported-by: Fengguang Wu <[email protected]> Tested-by: Fengguang Wu <[email protected]> Fix-creation-mandated-by: Linus Torvalds <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Cc: Robert Richter <[email protected]> Cc: [email protected] Cc: [email protected]

commit ab31fd0 upstream. v4.10 commit 6f2ce1c ("scsi: zfcp: fix rport unblock race with LUN recovery") extended accessing parent pointer fields of struct zfcp_erp_action for tracing. If an erp_action has never been enqueued before, these parent pointer fields are uninitialized and NULL. Examples are zfcp objects freshly added to the parent object's children list, before enqueueing their first recovery subsequently. In zfcp_erp_try_rport_unblock(), we iterate such list. Accessing erp_action fields can cause a NULL pointer dereference. Since the kernel can read from lowcore on s390, it does not immediately cause a kernel page fault. Instead it can cause hangs on trying to acquire the wrong erp_action->adapter->dbf->rec_lock in zfcp_dbf_rec_action_lvl() ^bogus^ while holding already other locks with IRQs disabled. Real life example from attaching lots of LUNs in parallel on many CPUs: crash> bt 17723 PID: 17723 TASK: ... CPU: 25 COMMAND: "zfcperp0.0.1800" LOWCORE INFO: -psw : 0x0404300180000000 0x000000000038e424 -function : _raw_spin_lock_wait_flags at 38e424 ... #0 [fdde8fc90] zfcp_dbf_rec_action_lvl at 3e0004e9862 [zfcp] #1 [fdde8fce8] zfcp_erp_try_rport_unblock at 3e0004dfddc [zfcp] #2 [fdde8fd38] zfcp_erp_strategy at 3e0004e0234 [zfcp] #3 [fdde8fda8] zfcp_erp_thread at 3e0004e0a12 [zfcp] #4 [fdde8fe60] kthread at 173550 #5 [fdde8feb8] kernel_thread_starter at 10add2 zfcp_adapter zfcp_port zfcp_unit <address>, 0x404040d600000000 scsi_device NULL, returning early! zfcp_scsi_dev.status = 0x40000000 0x40000000 ZFCP_STATUS_COMMON_RUNNING crash> zfcp_unit <address> struct zfcp_unit { erp_action = { adapter = 0x0, port = 0x0, unit = 0x0, }, } zfcp_erp_action is always fully embedded into its container object. Such container object is never moved in its object tree (only add or delete). Hence, erp_action parent pointers can never change. To fix the issue, initialize the erp_action parent pointers before adding the erp_action container to any list and thus before it becomes accessible from outside of its initializing function. In order to also close the time window between zfcp_erp_setup_act() memsetting the entire erp_action to zero and setting the parent pointers again, drop the memset and instead explicitly initialize individually all erp_action fields except for parent pointers. To be extra careful not to introduce any other unintended side effect, even keep zeroing the erp_action fields for list and timer. Also double-check with WARN_ON_ONCE that erp_action parent pointers never change, so we get to know when we would deviate from previous behavior. Signed-off-by: Steffen Maier <[email protected]> Fixes: 6f2ce1c ("scsi: zfcp: fix rport unblock race with LUN recovery") Reviewed-by: Benjamin Block <[email protected]> Signed-off-by: Martin K. Petersen <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>

commit a743bbe upstream. The warning below says it all: BUG: using __this_cpu_read() in preemptible [00000000] code: swapper/0/1 caller is __this_cpu_preempt_check CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.14.0-rc8 #4 Call Trace: dump_stack check_preemption_disabled ? do_early_param __this_cpu_preempt_check arch_perfmon_init op_nmi_init ? alloc_pci_root_info oprofile_arch_init oprofile_init do_one_initcall ... These accessors should not have been used in the first place: it is PPro so no mixed silicon revisions and thus it can simply use boot_cpu_data. Reported-by: Fengguang Wu <[email protected]> Tested-by: Fengguang Wu <[email protected]> Fix-creation-mandated-by: Linus Torvalds <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Cc: Robert Richter <[email protected]> Cc: [email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>

[ Upstream commit 962cc1a ] In commit f2e9ad2 ("xfs: check for race with xfs_reclaim_inode"), we skip an inode if we're racing with freeing the inode via xfs_reclaim_inode, but we forgot to release the rcu read lock when dumping the inode, with the result that we exit to userspace with a lock held. Don't do that; generic/320 with a 1k block size fails this very occasionally. ================================================ WARNING: lock held when returning to user space! 4.14.0-rc6-djwong open-power-host-os#4 Tainted: G W ------------------------------------------------ rm/30466 is leaving the kernel with locks still held! 1 lock held by rm/30466: #0: (rcu_read_lock){....}, at: [<ffffffffa01364d3>] xfs_ifree_cluster.isra.17+0x2c3/0x6f0 [xfs] ------------[ cut here ]------------ WARNING: CPU: 1 PID: 30466 at kernel/rcu/tree_plugin.h:329 rcu_note_context_switch+0x71/0x700 Modules linked in: deadline_iosched dm_snapshot dm_bufio ext4 mbcache jbd2 dm_flakey xfs libcrc32c dax_pmem device_dax nd_pmem sch_fq_codel af_packet [last unloaded: scsi_debug] CPU: 1 PID: 30466 Comm: rm Tainted: G W 4.14.0-rc6-djwong open-power-host-os#4 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.10.2-1ubuntu1djwong0 04/01/2014 task: ffff880037680000 task.stack: ffffc90001064000 RIP: 0010:rcu_note_context_switch+0x71/0x700 RSP: 0000:ffffc90001067e50 EFLAGS: 00010002 RAX: 0000000000000001 RBX: ffff880037680000 RCX: ffff88003e73d200 RDX: 0000000000000002 RSI: ffffffff819e53e9 RDI: ffffffff819f4375 RBP: 0000000000000000 R08: 0000000000000000 R09: ffff880062c900d0 R10: 0000000000000000 R11: 0000000000000000 R12: ffff880037680000 R13: 0000000000000000 R14: ffffc90001067eb8 R15: ffff880037680690 FS: 00007fa3b8ce8700(0000) GS:ffff88003ec00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f69bf77c000 CR3: 000000002450a000 CR4: 00000000000006e0 Call Trace: __schedule+0xb8/0xb10 schedule+0x40/0x90 exit_to_usermode_loop+0x6b/0xa0 prepare_exit_to_usermode+0x7a/0x90 retint_user+0x8/0x20 RIP: 0033:0x7fa3b87fda87 RSP: 002b:00007ffe41206568 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff02 RAX: 0000000000000000 RBX: 00000000010e88c0 RCX: 00007fa3b87fda87 RDX: 0000000000000000 RSI: 00000000010e89c8 RDI: 0000000000000005 RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000000 R10: 000000000000015e R11: 0000000000000246 R12: 00000000010c8060 R13: 00007ffe41206690 R14: 0000000000000000 R15: 0000000000000000 ---[ end trace e88f83bf0cfbd07d ]--- Fixes: f2e9ad2 Cc: Omar Sandoval <[email protected]> Signed-off-by: Darrick J. Wong <[email protected]> Reviewed-by: Christoph Hellwig <[email protected]> Reviewed-by: Omar Sandoval <[email protected]> Signed-off-by: Sasha Levin <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>

[ Upstream commit ec4fbd6 ] Dmitry reported a lockdep splat [1] (false positive) that we can fix by releasing the spinlock before calling icmp_send() from ip_expire() This is a false positive because sending an ICMP message can not possibly re-enter the IP frag engine. [1] [ INFO: possible circular locking dependency detected ] 4.10.0+ open-power-host-os#29 Not tainted ------------------------------------------------------- modprobe/12392 is trying to acquire lock: (_xmit_ETHER#2){+.-...}, at: [<ffffffff837a8182>] spin_lock include/linux/spinlock.h:299 [inline] (_xmit_ETHER#2){+.-...}, at: [<ffffffff837a8182>] __netif_tx_lock include/linux/netdevice.h:3486 [inline] (_xmit_ETHER#2){+.-...}, at: [<ffffffff837a8182>] sch_direct_xmit+0x282/0x6d0 net/sched/sch_generic.c:180 but task is already holding lock: (&(&q->lock)->rlock){+.-...}, at: [<ffffffff8389a4d1>] spin_lock include/linux/spinlock.h:299 [inline] (&(&q->lock)->rlock){+.-...}, at: [<ffffffff8389a4d1>] ip_expire+0x51/0x6c0 net/ipv4/ip_fragment.c:201 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> NXPower#1 (&(&q->lock)->rlock){+.-...}: validate_chain kernel/locking/lockdep.c:2267 [inline] __lock_acquire+0x2149/0x3430 kernel/locking/lockdep.c:3340 lock_acquire+0x2a1/0x630 kernel/locking/lockdep.c:3755 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x33/0x50 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:299 [inline] ip_defrag+0x3a2/0x4130 net/ipv4/ip_fragment.c:669 ip_check_defrag+0x4e3/0x8b0 net/ipv4/ip_fragment.c:713 packet_rcv_fanout+0x282/0x800 net/packet/af_packet.c:1459 deliver_skb net/core/dev.c:1834 [inline] dev_queue_xmit_nit+0x294/0xa90 net/core/dev.c:1890 xmit_one net/core/dev.c:2903 [inline] dev_hard_start_xmit+0x16b/0xab0 net/core/dev.c:2923 sch_direct_xmit+0x31f/0x6d0 net/sched/sch_generic.c:182 __dev_xmit_skb net/core/dev.c:3092 [inline] __dev_queue_xmit+0x13e5/0x1e60 net/core/dev.c:3358 dev_queue_xmit+0x17/0x20 net/core/dev.c:3423 neigh_resolve_output+0x6b9/0xb10 net/core/neighbour.c:1308 neigh_output include/net/neighbour.h:478 [inline] ip_finish_output2+0x8b8/0x15a0 net/ipv4/ip_output.c:228 ip_do_fragment+0x1d93/0x2720 net/ipv4/ip_output.c:672 ip_fragment.constprop.54+0x145/0x200 net/ipv4/ip_output.c:545 ip_finish_output+0x82d/0xe10 net/ipv4/ip_output.c:314 NF_HOOK_COND include/linux/netfilter.h:246 [inline] ip_output+0x1f0/0x7a0 net/ipv4/ip_output.c:404 dst_output include/net/dst.h:486 [inline] ip_local_out+0x95/0x170 net/ipv4/ip_output.c:124 ip_send_skb+0x3c/0xc0 net/ipv4/ip_output.c:1492 ip_push_pending_frames+0x64/0x80 net/ipv4/ip_output.c:1512 raw_sendmsg+0x26de/0x3a00 net/ipv4/raw.c:655 inet_sendmsg+0x164/0x5b0 net/ipv4/af_inet.c:761 sock_sendmsg_nosec net/socket.c:633 [inline] sock_sendmsg+0xca/0x110 net/socket.c:643 ___sys_sendmsg+0x4a3/0x9f0 net/socket.c:1985 __sys_sendmmsg+0x25c/0x750 net/socket.c:2075 SYSC_sendmmsg net/socket.c:2106 [inline] SyS_sendmmsg+0x35/0x60 net/socket.c:2101 do_syscall_64+0x2e8/0x930 arch/x86/entry/common.c:281 return_from_SYSCALL_64+0x0/0x7a -> #0 (_xmit_ETHER#2){+.-...}: check_prev_add kernel/locking/lockdep.c:1830 [inline] check_prevs_add+0xa8f/0x19f0 kernel/locking/lockdep.c:1940 validate_chain kernel/locking/lockdep.c:2267 [inline] __lock_acquire+0x2149/0x3430 kernel/locking/lockdep.c:3340 lock_acquire+0x2a1/0x630 kernel/locking/lockdep.c:3755 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x33/0x50 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:299 [inline] __netif_tx_lock include/linux/netdevice.h:3486 [inline] sch_direct_xmit+0x282/0x6d0 net/sched/sch_generic.c:180 __dev_xmit_skb net/core/dev.c:3092 [inline] __dev_queue_xmit+0x13e5/0x1e60 net/core/dev.c:3358 dev_queue_xmit+0x17/0x20 net/core/dev.c:3423 neigh_hh_output include/net/neighbour.h:468 [inline] neigh_output include/net/neighbour.h:476 [inline] ip_finish_output2+0xf6c/0x15a0 net/ipv4/ip_output.c:228 ip_finish_output+0xa29/0xe10 net/ipv4/ip_output.c:316 NF_HOOK_COND include/linux/netfilter.h:246 [inline] ip_output+0x1f0/0x7a0 net/ipv4/ip_output.c:404 dst_output include/net/dst.h:486 [inline] ip_local_out+0x95/0x170 net/ipv4/ip_output.c:124 ip_send_skb+0x3c/0xc0 net/ipv4/ip_output.c:1492 ip_push_pending_frames+0x64/0x80 net/ipv4/ip_output.c:1512 icmp_push_reply+0x372/0x4d0 net/ipv4/icmp.c:394 icmp_send+0x156c/0x1c80 net/ipv4/icmp.c:754 ip_expire+0x40e/0x6c0 net/ipv4/ip_fragment.c:239 call_timer_fn+0x241/0x820 kernel/time/timer.c:1268 expire_timers kernel/time/timer.c:1307 [inline] __run_timers+0x960/0xcf0 kernel/time/timer.c:1601 run_timer_softirq+0x21/0x80 kernel/time/timer.c:1614 __do_softirq+0x31f/0xbe7 kernel/softirq.c:284 invoke_softirq kernel/softirq.c:364 [inline] irq_exit+0x1cc/0x200 kernel/softirq.c:405 exiting_irq arch/x86/include/asm/apic.h:657 [inline] smp_apic_timer_interrupt+0x76/0xa0 arch/x86/kernel/apic/apic.c:962 apic_timer_interrupt+0x93/0xa0 arch/x86/entry/entry_64.S:707 __read_once_size include/linux/compiler.h:254 [inline] atomic_read arch/x86/include/asm/atomic.h:26 [inline] rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:350 [inline] __rcu_is_watching kernel/rcu/tree.c:1133 [inline] rcu_is_watching+0x83/0x110 kernel/rcu/tree.c:1147 rcu_read_lock_held+0x87/0xc0 kernel/rcu/update.c:293 radix_tree_deref_slot include/linux/radix-tree.h:238 [inline] filemap_map_pages+0x6d4/0x1570 mm/filemap.c:2335 do_fault_around mm/memory.c:3231 [inline] do_read_fault mm/memory.c:3265 [inline] do_fault+0xbd5/0x2080 mm/memory.c:3370 handle_pte_fault mm/memory.c:3600 [inline] __handle_mm_fault+0x1062/0x2cb0 mm/memory.c:3714 handle_mm_fault+0x1e2/0x480 mm/memory.c:3751 __do_page_fault+0x4f6/0xb60 arch/x86/mm/fault.c:1397 do_page_fault+0x54/0x70 arch/x86/mm/fault.c:1460 page_fault+0x28/0x30 arch/x86/entry/entry_64.S:1011 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&(&q->lock)->rlock); lock(_xmit_ETHER#2); lock(&(&q->lock)->rlock); lock(_xmit_ETHER#2); *** DEADLOCK *** 10 locks held by modprobe/12392: #0: (&mm->mmap_sem){++++++}, at: [<ffffffff81329758>] __do_page_fault+0x2b8/0xb60 arch/x86/mm/fault.c:1336 NXPower#1: (rcu_read_lock){......}, at: [<ffffffff8188cab6>] filemap_map_pages+0x1e6/0x1570 mm/filemap.c:2324 open-power-host-os#2: (&(ptlock_ptr(page))->rlock#2){+.+...}, at: [<ffffffff81984a78>] spin_lock include/linux/spinlock.h:299 [inline] open-power-host-os#2: (&(ptlock_ptr(page))->rlock#2){+.+...}, at: [<ffffffff81984a78>] pte_alloc_one_map mm/memory.c:2944 [inline] open-power-host-os#2: (&(ptlock_ptr(page))->rlock#2){+.+...}, at: [<ffffffff81984a78>] alloc_set_pte+0x13b8/0x1b90 mm/memory.c:3072 open-power-host-os#3: (((&q->timer))){+.-...}, at: [<ffffffff81627e72>] lockdep_copy_map include/linux/lockdep.h:175 [inline] open-power-host-os#3: (((&q->timer))){+.-...}, at: [<ffffffff81627e72>] call_timer_fn+0x1c2/0x820 kernel/time/timer.c:1258 open-power-host-os#4: (&(&q->lock)->rlock){+.-...}, at: [<ffffffff8389a4d1>] spin_lock include/linux/spinlock.h:299 [inline] open-power-host-os#4: (&(&q->lock)->rlock){+.-...}, at: [<ffffffff8389a4d1>] ip_expire+0x51/0x6c0 net/ipv4/ip_fragment.c:201 open-power-host-os#5: (rcu_read_lock){......}, at: [<ffffffff8389a633>] ip_expire+0x1b3/0x6c0 net/ipv4/ip_fragment.c:216 open-power-host-os#6: (slock-AF_INET){+.-...}, at: [<ffffffff839b3313>] spin_trylock include/linux/spinlock.h:309 [inline] open-power-host-os#6: (slock-AF_INET){+.-...}, at: [<ffffffff839b3313>] icmp_xmit_lock net/ipv4/icmp.c:219 [inline] open-power-host-os#6: (slock-AF_INET){+.-...}, at: [<ffffffff839b3313>] icmp_send+0x803/0x1c80 net/ipv4/icmp.c:681 open-power-host-os#7: (rcu_read_lock_bh){......}, at: [<ffffffff838ab9a1>] ip_finish_output2+0x2c1/0x15a0 net/ipv4/ip_output.c:198 open-power-host-os#8: (rcu_read_lock_bh){......}, at: [<ffffffff836d1dee>] __dev_queue_xmit+0x23e/0x1e60 net/core/dev.c:3324 open-power-host-os#9: (dev->qdisc_running_key ?: &qdisc_running_key){+.....}, at: [<ffffffff836d3a27>] dev_queue_xmit+0x17/0x20 net/core/dev.c:3423 stack backtrace: CPU: 0 PID: 12392 Comm: modprobe Not tainted 4.10.0+ open-power-host-os#29 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: <IRQ> __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x2ee/0x3ef lib/dump_stack.c:52 print_circular_bug+0x307/0x3b0 kernel/locking/lockdep.c:1204 check_prev_add kernel/locking/lockdep.c:1830 [inline] check_prevs_add+0xa8f/0x19f0 kernel/locking/lockdep.c:1940 validate_chain kernel/locking/lockdep.c:2267 [inline] __lock_acquire+0x2149/0x3430 kernel/locking/lockdep.c:3340 lock_acquire+0x2a1/0x630 kernel/locking/lockdep.c:3755 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x33/0x50 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:299 [inline] __netif_tx_lock include/linux/netdevice.h:3486 [inline] sch_direct_xmit+0x282/0x6d0 net/sched/sch_generic.c:180 __dev_xmit_skb net/core/dev.c:3092 [inline] __dev_queue_xmit+0x13e5/0x1e60 net/core/dev.c:3358 dev_queue_xmit+0x17/0x20 net/core/dev.c:3423 neigh_hh_output include/net/neighbour.h:468 [inline] neigh_output include/net/neighbour.h:476 [inline] ip_finish_output2+0xf6c/0x15a0 net/ipv4/ip_output.c:228 ip_finish_output+0xa29/0xe10 net/ipv4/ip_output.c:316 NF_HOOK_COND include/linux/netfilter.h:246 [inline] ip_output+0x1f0/0x7a0 net/ipv4/ip_output.c:404 dst_output include/net/dst.h:486 [inline] ip_local_out+0x95/0x170 net/ipv4/ip_output.c:124 ip_send_skb+0x3c/0xc0 net/ipv4/ip_output.c:1492 ip_push_pending_frames+0x64/0x80 net/ipv4/ip_output.c:1512 icmp_push_reply+0x372/0x4d0 net/ipv4/icmp.c:394 icmp_send+0x156c/0x1c80 net/ipv4/icmp.c:754 ip_expire+0x40e/0x6c0 net/ipv4/ip_fragment.c:239 call_timer_fn+0x241/0x820 kernel/time/timer.c:1268 expire_timers kernel/time/timer.c:1307 [inline] __run_timers+0x960/0xcf0 kernel/time/timer.c:1601 run_timer_softirq+0x21/0x80 kernel/time/timer.c:1614 __do_softirq+0x31f/0xbe7 kernel/softirq.c:284 invoke_softirq kernel/softirq.c:364 [inline] irq_exit+0x1cc/0x200 kernel/softirq.c:405 exiting_irq arch/x86/include/asm/apic.h:657 [inline] smp_apic_timer_interrupt+0x76/0xa0 arch/x86/kernel/apic/apic.c:962 apic_timer_interrupt+0x93/0xa0 arch/x86/entry/entry_64.S:707 RIP: 0010:__read_once_size include/linux/compiler.h:254 [inline] RIP: 0010:atomic_read arch/x86/include/asm/atomic.h:26 [inline] RIP: 0010:rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:350 [inline] RIP: 0010:__rcu_is_watching kernel/rcu/tree.c:1133 [inline] RIP: 0010:rcu_is_watching+0x83/0x110 kernel/rcu/tree.c:1147 RSP: 0000:ffff8801c391f120 EFLAGS: 00000a03 ORIG_RAX: ffffffffffffff10 RAX: dffffc0000000000 RBX: ffff8801c391f148 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 000055edd4374000 RDI: ffff8801dbe1ae0c RBP: ffff8801c391f1a0 R08: 0000000000000002 R09: 0000000000000000 R10: dffffc0000000000 R11: 0000000000000002 R12: 1ffff10038723e25 R13: ffff8801dbe1ae00 R14: ffff8801c391f680 R15: dffffc0000000000 </IRQ> rcu_read_lock_held+0x87/0xc0 kernel/rcu/update.c:293 radix_tree_deref_slot include/linux/radix-tree.h:238 [inline] filemap_map_pages+0x6d4/0x1570 mm/filemap.c:2335 do_fault_around mm/memory.c:3231 [inline] do_read_fault mm/memory.c:3265 [inline] do_fault+0xbd5/0x2080 mm/memory.c:3370 handle_pte_fault mm/memory.c:3600 [inline] __handle_mm_fault+0x1062/0x2cb0 mm/memory.c:3714 handle_mm_fault+0x1e2/0x480 mm/memory.c:3751 __do_page_fault+0x4f6/0xb60 arch/x86/mm/fault.c:1397 do_page_fault+0x54/0x70 arch/x86/mm/fault.c:1460 page_fault+0x28/0x30 arch/x86/entry/entry_64.S:1011 RIP: 0033:0x7f83172f2786 RSP: 002b:00007fffe859ae80 EFLAGS: 00010293 RAX: 000055edd4373040 RBX: 00007f83175111c8 RCX: 000055edd4373238 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007f8317510970 RBP: 00007fffe859afd0 R08: 0000000000000009 R09: 0000000000000000 R10: 0000000000000064 R11: 0000000000000000 R12: 000055edd4373040 R13: 0000000000000000 R14: 00007fffe859afe8 R15: 0000000000000000 Signed-off-by: Eric Dumazet <[email protected]> Reported-by: Dmitry Vyukov <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Sasha Levin <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>

Lockdep gifted us with noticing the following 4-way lockup scenario: perf_trace_init() #0 mutex_lock(&event_mutex) perf_trace_event_init() perf_trace_event_reg() tp_event->class->reg() := tracepoint_probe_register #1 mutex_lock(&tracepoints_mutex) trace_point_add_func() #2 static_key_enable() #2 do_cpu_up() perf_event_init_cpu() #3 mutex_lock(&pmus_lock) #4 mutex_lock(&ctx->mutex) perf_event_task_disable() mutex_lock(&current->perf_event_mutex) #4 ctx = perf_event_ctx_lock() #5 perf_event_for_each_child() do_exit() task_work_run() __fput() perf_release() perf_event_release_kernel() #4 mutex_lock(&ctx->mutex) #5 mutex_lock(&event->child_mutex) free_event() _free_event() event->destroy() := perf_trace_destroy #0 mutex_lock(&event_mutex); Fix that by moving the free_event() out from under the locks. Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Stephane Eranian <[email protected]> Cc: Steven Rostedt (VMware) <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Vince Weaver <[email protected]> Cc: [email protected] Signed-off-by: Ingo Molnar <[email protected]>

Lockdep noticed the following 3-way lockup race: perf_trace_init() #0 mutex_lock(&event_mutex) perf_trace_event_init() perf_trace_event_reg() tp_event->class->reg() := tracepoint_probe_register #1 mutex_lock(&tracepoints_mutex) trace_point_add_func() #2 static_key_enable() #2 do_cpu_up() perf_event_init_cpu() #3 mutex_lock(&pmus_lock) #4 mutex_lock(&ctx->mutex) perf_ioctl() #4 ctx = perf_event_ctx_lock() _perf_iotcl() ftrace_profile_set_filter() #0 mutex_lock(&event_mutex) Fudge it for now by noting that the tracepoint state does not depend on the event <-> context relation. Ugly though :/ Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: Thomas Gleixner <[email protected]> Signed-off-by: Ingo Molnar <[email protected]>

More lockdep gifts, a 5-way lockup race: perf_event_create_kernel_counter() perf_event_alloc() perf_try_init_event() x86_pmu_event_init() __x86_pmu_event_init() x86_reserve_hardware() #0 mutex_lock(&pmc_reserve_mutex); reserve_ds_buffer() #1 get_online_cpus() perf_event_release_kernel() _free_event() hw_perf_event_destroy() x86_release_hardware() #0 mutex_lock(&pmc_reserve_mutex) release_ds_buffer() #1 get_online_cpus() #1 do_cpu_up() perf_event_init_cpu() #2 mutex_lock(&pmus_lock) #3 mutex_lock(&ctx->mutex) sys_perf_event_open() mutex_lock_double() #3 mutex_lock(ctx->mutex) #4 mutex_lock_nested(ctx->mutex, 1); perf_try_init_event() #4 mutex_lock_nested(ctx->mutex, 1) x86_pmu_event_init() intel_pmu_hw_config() x86_add_exclusive() #0 mutex_lock(&pmc_reserve_mutex) Fix it by using ordering constructs instead of locking. Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Stephane Eranian <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Vince Weaver <[email protected]> Cc: [email protected] Signed-off-by: Ingo Molnar <[email protected]>

iproute2 print_skbmod() prints the configured ethertype using format 0x%X: therefore, test 9aa8 systematically fails, because it configures action #4 using ethertype 0x0031, and expects 0x0031 when it reads it back. Changing the expected value to 0x31 lets the test result 'not ok' become 'ok'. tested with: # ./tdc.py -e 9aa8 Test 9aa8: Get a single skbmod action from a list All test results: 1..1 ok 1 9aa8 Get a single skbmod action from a list Fixes: cf797ac ("tc-testing: Add test cases for police and skbmod") Signed-off-by: Davide Caratti <[email protected]> Signed-off-by: David S. Miller <[email protected]>

Currently we can crash perf record when running in pipe mode, like: $ perf record ls | perf report # To display the perf.data header info, please use --header/--header-only options. # perf: Segmentation fault Error: The - file has no samples! The callstack of the crash is: 0x0000000000515242 in perf_event__synthesize_event_update_name 3513 ev = event_update_event__new(len + 1, PERF_EVENT_UPDATE__NAME, evsel->id[0]); (gdb) bt #0 0x0000000000515242 in perf_event__synthesize_event_update_name #1 0x00000000005158a4 in perf_event__synthesize_extra_attr #2 0x0000000000443347 in record__synthesize #3 0x00000000004438e3 in __cmd_record #4 0x000000000044514e in cmd_record #5 0x00000000004cbc95 in run_builtin #6 0x00000000004cbf02 in handle_internal_command #7 0x00000000004cc054 in run_argv #8 0x00000000004cc422 in main The reason of the crash is that the evsel does not have ids array allocated and the pipe's synthesize code tries to access it. We don't force evsel ids allocation when we have single event, because it's not needed. However we need it when we are in pipe mode even for single event as a key for evsel update event. Fixing this by forcing evsel ids allocation event for single event, when we are in pipe mode. Signed-off-by: Jiri Olsa <[email protected]> Tested-by: Arnaldo Carvalho de Melo <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: David Ahern <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Peter Zijlstra <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

After v4.12 commit e2460f2 ("dm: mark targets that pass integrity data"), dm-multipath, e.g. on DIF+DIX SCSI disk paths, does not support block integrity any more. So add it to the whitelist. This is also a pre-requisite to use block integrity with other dm layer(s) on top of multipath, such as kpartx partitions (dm-linear) or LVM. Also, bump target version to reflect this fix. Fixes: e2460f2 ("dm: mark targets that pass integrity data") Cc: <[email protected]> #4.12+ Bisected-by: Fedor Loshakov <[email protected]> Signed-off-by: Steffen Maier <[email protected]> Reviewed-by: Hannes Reinecke <[email protected]> Reviewed-by: Martin K. Petersen <[email protected]> Signed-off-by: Mike Snitzer <[email protected]>

cdeadmin mentioned this issue Feb 23, 2018

hard lockup detected when vm starts with ftrace on #22

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Upstreaming: Alexey's patchset "powerpc/spapr/vfio: Put pages on VFIO container shutdown" #4

Upstreaming: Alexey's patchset "powerpc/spapr/vfio: Put pages on VFIO container shutdown" #4

paulusmack commented Nov 2, 2016

Upstreaming: Alexey's patchset "powerpc/spapr/vfio: Put pages on VFIO container shutdown" #4

Upstreaming: Alexey's patchset "powerpc/spapr/vfio: Put pages on VFIO container shutdown" #4

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paulusmack commented Nov 2, 2016