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b11e3d782b
While booting, the following message is seen: [ 21.665087] =============================== [ 21.669439] [ INFO: suspicious RCU usage. ] [ 21.673798] 3.2.0-0.0.0.28.36b5ec9-default #2 Not tainted [ 21.681353] ------------------------------- [ 21.685864] arch/x86/kernel/cpu/mcheck/mce.c:194 suspicious rcu_dereference_index_check() usage! [ 21.695013] [ 21.695014] other info that might help us debug this: [ 21.695016] [ 21.703488] [ 21.703489] rcu_scheduler_active = 1, debug_locks = 1 [ 21.710426] 3 locks held by modprobe/2139: [ 21.714754] #0: (&__lockdep_no_validate__){......}, at: [<ffffffff8133afd3>] __driver_attach+0x53/0xa0 [ 21.725020] #1: [ 21.725323] ioatdma: Intel(R) QuickData Technology Driver 4.00 [ 21.733206] (&__lockdep_no_validate__){......}, at: [<ffffffff8133afe1>] __driver_attach+0x61/0xa0 [ 21.743015] #2: (i7core_edac_lock){+.+.+.}, at: [<ffffffffa01cfa5f>] i7core_probe+0x1f/0x5c0 [i7core_edac] [ 21.753708] [ 21.753709] stack backtrace: [ 21.758429] Pid: 2139, comm: modprobe Not tainted 3.2.0-0.0.0.28.36b5ec9-default #2 [ 21.768253] Call Trace: [ 21.770838] [<ffffffff810977cd>] lockdep_rcu_suspicious+0xcd/0x100 [ 21.777366] [<ffffffff8101aa41>] drain_mcelog_buffer+0x191/0x1b0 [ 21.783715] [<ffffffff8101aa78>] mce_register_decode_chain+0x18/0x20 [ 21.790430] [<ffffffffa01cf8db>] i7core_register_mci+0x2fb/0x3e4 [i7core_edac] [ 21.798003] [<ffffffffa01cfb14>] i7core_probe+0xd4/0x5c0 [i7core_edac] [ 21.804809] [<ffffffff8129566b>] local_pci_probe+0x5b/0xe0 [ 21.810631] [<ffffffff812957c9>] __pci_device_probe+0xd9/0xe0 [ 21.816650] [<ffffffff813362e4>] ? get_device+0x14/0x20 [ 21.822178] [<ffffffff81296916>] pci_device_probe+0x36/0x60 [ 21.828061] [<ffffffff8133ac8a>] really_probe+0x7a/0x2b0 [ 21.833676] [<ffffffff8133af23>] driver_probe_device+0x63/0xc0 [ 21.839868] [<ffffffff8133b01b>] __driver_attach+0x9b/0xa0 [ 21.845718] [<ffffffff8133af80>] ? driver_probe_device+0xc0/0xc0 [ 21.852027] [<ffffffff81339168>] bus_for_each_dev+0x68/0x90 [ 21.857876] [<ffffffff8133aa3c>] driver_attach+0x1c/0x20 [ 21.863462] [<ffffffff8133a64d>] bus_add_driver+0x16d/0x2b0 [ 21.869377] [<ffffffff8133b6dc>] driver_register+0x7c/0x160 [ 21.875220] [<ffffffff81296bda>] __pci_register_driver+0x6a/0xf0 [ 21.881494] [<ffffffffa01fe000>] ? 0xffffffffa01fdfff [ 21.886846] [<ffffffffa01fe047>] i7core_init+0x47/0x1000 [i7core_edac] [ 21.893737] [<ffffffff810001ce>] do_one_initcall+0x3e/0x180 [ 21.899670] [<ffffffff810a9b95>] sys_init_module+0xc5/0x220 [ 21.905542] [<ffffffff8149bc39>] system_call_fastpath+0x16/0x1b Fix this by using ACCESS_ONCE() instead of rcu_dereference_check_mce() over mcelog.next. Since the access to each entry is controlled by the ->finished field, ACCESS_ONCE() should work just fine. An rcu_dereference is unnecessary here. Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Suggested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Tony Luck <tony.luck@intel.com> Signed-off-by: Borislav Petkov <borislav.petkov@amd.com> |
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| .. | ||
| boot | ||
| configs | ||
| crypto | ||
| ia32 | ||
| include/asm | ||
| kernel | ||
| kvm | ||
| lguest | ||
| lib | ||
| math-emu | ||
| mm | ||
| net | ||
| oprofile | ||
| pci | ||
| platform | ||
| power | ||
| syscalls | ||
| tools | ||
| um | ||
| vdso | ||
| video | ||
| xen | ||
| .gitignore | ||
| Kbuild | ||
| Kconfig | ||
| Kconfig.cpu | ||
| Kconfig.debug | ||
| Makefile | ||
| Makefile_32.cpu | ||
| Makefile.um | ||