On 2015/07/07 6:27, Vince Weaver wrote: > Hello > > I've been working on trying to get the perf_fuzzer to start fuzzing the > PERF_EVENT_IOC_SET_BPF so I've added some really hackish kprobe support. > > However before I can get to the BPF testing the kprobe code generates a > constant stream of WARNINGS which make the machine more or less useless > until I stop it. I've included a small selection here. > > Is this expected?
Did you get same message without BPF hack? And also, could you tell us your kernel version and configuration? > > Vince > > > [ 3521.350839] ftrace: Failed on adding breakpoints (6056): > [ 3521.357877] ------------[ cut here ]------------ > [ 3521.363007] WARNING: CPU: 1 PID: 5080 at kernel/trace/ftrace.c:1951 > ftrace_bug+0x245/0x320() > [ 3521.449830] CPU: 1 PID: 5080 Comm: perf_fuzzer Not tainted 4.2.0-rc1+ #168 > [ 3521.457543] Hardware name: LENOVO 10AM000AUS/SHARKBAY, BIOS FBKT72AUS > 01/26/2014 > [ 3521.465820] ffffffff81a28cf6 ffff8800cd9f7b48 ffffffff816a10a3 > 0000000000000000 > [ 3521.474274] 0000000000000000 ffff8800cd9f7b88 ffffffff8106ec8a > ffff8800cd9f7b68 > [ 3521.482680] ffff880119bd7a80 ffffffff81196730 ffff880119bd7a80 > 00000000000017a8 > [ 3521.491143] Call Trace: > [ 3521.494128] [<ffffffff816a10a3>] dump_stack+0x45/0x57 > [ 3521.500016] [<ffffffff8106ec8a>] warn_slowpath_common+0x8a/0xc0 > [ 3521.506810] [<ffffffff81196730>] ? vm_insert_mixed+0x40/0x40 > [ 3521.513389] [<ffffffff8106ed7a>] warn_slowpath_null+0x1a/0x20 > [ 3521.520025] [<ffffffff81123425>] ftrace_bug+0x245/0x320 > [ 3521.526147] [<ffffffff81052d5c>] ftrace_replace_code+0x24c/0x360 > [ 3521.533102] [<ffffffff81123d3c>] ftrace_modify_all_code+0x9c/0x120 > [ 3521.540241] [<ffffffff81052e80>] arch_ftrace_update_code+0x10/0x20 > [ 3521.547396] [<ffffffff81123e30>] ftrace_run_update_code+0x20/0x80 > [ 3521.554425] [<ffffffff811244df>] ftrace_startup_enable+0x2f/0x40 > [ 3521.561376] [<ffffffff811256e6>] ftrace_startup+0xd6/0x230 > [ 3521.567772] [<ffffffff81125c24>] register_ftrace_function+0x54/0x70 > [ 3521.575025] [<ffffffff8113df07>] perf_ftrace_event_register+0x47/0x140 > [ 3521.582537] [<ffffffff8113dba4>] perf_trace_init+0xc4/0x2c0 > [ 3521.589050] [<ffffffff81152e8a>] perf_tp_event_init+0x2a/0x50 > [ 3521.595771] [<ffffffff8115448b>] perf_try_init_event+0x8b/0xa0 > [ 3521.602572] [<ffffffff8115bf63>] perf_init_event+0x133/0x160 > [ 3521.609181] [<ffffffff8115be30>] ? perf_bp_event+0x90/0x90 > [ 3521.615647] [<ffffffff8115c3ba>] perf_event_alloc+0x42a/0x680 > [ 3521.622388] [<ffffffff8115c9d7>] SYSC_perf_event_open+0x3c7/0xd20 > [ 3521.629487] [<ffffffff8105f86b>] ? __do_page_fault+0x1ab/0x3f0 > [ 3521.636320] [<ffffffff8115d7a9>] SyS_perf_event_open+0x9/0x10 > [ 3521.643087] [<ffffffff816a8df2>] entry_SYSCALL_64_fastpath+0x16/0x7a > [ 3521.650521] ---[ end trace a413501925547ed5 ]--- > [ 3521.655960] ftrace failed to modify [<ffffffff81196730>] > handle_mm_fault+0x0/0x1750 > [ 3521.664767] actual: e8:cb:18:ef:1e Hmm, this seems to happen when disarming kprobes from handle_mm_fault+0. However, with this easy test, I couldn't reproduce it on the latest tip/master. [root@localhost tracing]# echo p handle_mm_fault > kprobe_events [root@localhost tracing]# echo 1 > events/kprobes/p_handle_mm_fault_0/enable [root@localhost tracing]# echo 0 > events/kprobes/p_handle_mm_fault_0/enable We'd better know how to reproduce this issue. Thank you, > [ 3521.669202] ftrace record flags: ec000002 > [ 3521.673993] (2) R tramp: 0xffffffffa0090000 expected tramp: > ffffffffa0090000 > > > [ 3521.834024] ------------[ cut here ]------------ > [ 3521.839442] WARNING: CPU: 2 PID: 5177 at kernel/kprobes.c:955 > disarm_kprobe+0xf8/0x100() > [ 3521.848577] Failed to init kprobe-ftrace (-19) > [ 3521.931384] CPU: 2 PID: 5177 Comm: perf_fuzzer Tainted: G W > 4.2.0-rc1+ #168 > [ 3521.940498] Hardware name: LENOVO 10AM000AUS/SHARKBAY, BIOS FBKT72AUS > 01/26/2014 > [ 3521.948854] ffffffff81a28976 ffff8800bf6d7a48 ffffffff816a10a3 > 0000000000000000 > [ 3521.957335] ffff8800bf6d7a98 ffff8800bf6d7a88 ffffffff8106ec8a > ffffffff81124f6a > [ 3521.965839] ffff8800cd4e2010 ffff8800cd4e2010 ffff8800cd4e2000 > ffff8800cd28a000 > [ 3521.974275] Call Trace: > [ 3521.977335] [<ffffffff816a10a3>] dump_stack+0x45/0x57 > [ 3521.983302] [<ffffffff8106ec8a>] warn_slowpath_common+0x8a/0xc0 > [ 3521.990170] [<ffffffff81124f6a>] ? unregister_ftrace_function+0x1a/0x50 > [ 3521.997784] [<ffffffff8106ed06>] warn_slowpath_fmt+0x46/0x50 > [ 3522.004418] [<ffffffff816a693e>] ? mutex_unlock+0xe/0x10 > [ 3522.010640] [<ffffffff81119208>] disarm_kprobe+0xf8/0x100 > [ 3522.016972] [<ffffffff811192a9>] __disable_kprobe+0x99/0xc0 > [ 3522.023491] [<ffffffff811192f7>] disable_kprobe+0x27/0x50 > [ 3522.029827] [<ffffffff81142863>] disable_trace_kprobe+0xc3/0xf0 > [ 3522.036708] [<ffffffff8114345d>] kprobe_register+0x2d/0xe0 > [ 3522.043102] [<ffffffff8113da83>] perf_trace_event_unreg.isra.1+0x33/0x90 > [ 3522.050808] [<ffffffff8113dddc>] perf_trace_destroy+0x3c/0x50 > [ 3522.057482] [<ffffffff81152eb9>] tp_perf_event_destroy+0x9/0x10 > [ 3522.064354] [<ffffffff81158fc1>] _free_event+0xc1/0x250 > [ 3522.070474] [<ffffffff8115917b>] ? put_event+0x2b/0x150 > [ 3522.076625] [<ffffffff811592ef>] free_event+0x1f/0x50 > [ 3522.082531] [<ffffffff8115d9f5>] perf_event_exit_task+0x245/0x300 > [ 3522.089575] [<ffffffff81071622>] do_exit+0x3b2/0xa90 > [ 3522.095444] [<ffffffff8107d182>] ? get_signal+0xe2/0x720 > [ 3522.101659] [<ffffffff81071da4>] do_group_exit+0x54/0xe0 > [ 3522.107892] [<ffffffff8107d320>] get_signal+0x280/0x720 > [ 3522.114046] [<ffffffff81013478>] do_signal+0x28/0xb50 > [ 3522.119984] [<ffffffff810b78f6>] ? __lock_acquire.isra.31+0x3a6/0xf90 > [ 3522.127411] [<ffffffff810815a5>] ? sys_getppid+0x5/0x80 > [ 3522.133563] [<ffffffff81014002>] do_notify_resume+0x62/0x70 > [ 3522.140084] [<ffffffff816a9ade>] retint_signal+0x44/0x86 > [ 3522.146349] ---[ end trace a413501925547ed6 ]--- > > > > [ 3522.157157] WARNING: CPU: 2 PID: 5177 at kernel/kprobes.c:959 > disarm_kprobe+0xca/0x100() > [ 3522.166266] Failed to disarm kprobe-ftrace at ffffffff81196730 (-19) > [ 3522.251364] CPU: 2 PID: 5177 Comm: perf_fuzzer Tainted: G W > 4.2.0-rc1+ #168 > [ 3522.260488] Hardware name: LENOVO 10AM000AUS/SHARKBAY, BIOS FBKT72AUS > 01/26/2014 > [ 3522.268953] ffffffff81a28976 ffff8800bf6d7a48 ffffffff816a10a3 > 0000000000000000 > [ 3522.277482] ffff8800bf6d7a98 ffff8800bf6d7a88 ffffffff8106ec8a > ffffffff81124f6a > [ 3522.285993] ffff8800cd4e2010 ffff8800cd4e2010 ffff8800cd4e2000 > ffff8800cd28a000 > [ 3522.294520] Call Trace: > [ 3522.297594] [<ffffffff816a10a3>] dump_stack+0x45/0x57 > [ 3522.303535] [<ffffffff8106ec8a>] warn_slowpath_common+0x8a/0xc0 > [ 3522.310379] [<ffffffff81124f6a>] ? unregister_ftrace_function+0x1a/0x50 > [ 3522.318026] [<ffffffff8106ed06>] warn_slowpath_fmt+0x46/0x50 > [ 3522.324637] [<ffffffff816a693e>] ? mutex_unlock+0xe/0x10 > [ 3522.330859] [<ffffffff81196730>] ? vm_insert_mixed+0x40/0x40 > [ 3522.337459] [<ffffffff811191da>] disarm_kprobe+0xca/0x100 > [ 3522.343792] [<ffffffff811192a9>] __disable_kprobe+0x99/0xc0 > [ 3522.350304] [<ffffffff811192f7>] disable_kprobe+0x27/0x50 > [ 3522.356692] [<ffffffff81142863>] disable_trace_kprobe+0xc3/0xf0 > [ 3522.363510] [<ffffffff8114345d>] kprobe_register+0x2d/0xe0 > [ 3522.369907] [<ffffffff8113da83>] perf_trace_event_unreg.isra.1+0x33/0x90 > [ 3522.377620] [<ffffffff8113dddc>] perf_trace_destroy+0x3c/0x50 > [ 3522.384337] [<ffffffff81152eb9>] tp_perf_event_destroy+0x9/0x10 > [ 3522.391215] [<ffffffff81158fc1>] _free_event+0xc1/0x250 > [ 3522.397348] [<ffffffff8115917b>] ? put_event+0x2b/0x150 > [ 3522.403478] [<ffffffff811592ef>] free_event+0x1f/0x50 > [ 3522.409443] [<ffffffff8115d9f5>] perf_event_exit_task+0x245/0x300 > [ 3522.416466] [<ffffffff81071622>] do_exit+0x3b2/0xa90 > [ 3522.422351] [<ffffffff8107d182>] ? get_signal+0xe2/0x720 > [ 3522.428555] [<ffffffff81071da4>] do_group_exit+0x54/0xe0 > [ 3522.434803] [<ffffffff8107d320>] get_signal+0x280/0x720 > [ 3522.440974] [<ffffffff81013478>] do_signal+0x28/0xb50 > [ 3522.446949] [<ffffffff810b78f6>] ? __lock_acquire.isra.31+0x3a6/0xf90 > [ 3522.454420] [<ffffffff810815a5>] ? sys_getppid+0x5/0x80 > [ 3522.460592] [<ffffffff81014002>] do_notify_resume+0x62/0x70 > [ 3522.467079] [<ffffffff816a9ade>] retint_signal+0x44/0x86 > [ 3522.473343] ---[ end trace a413501925547ed7 ]--- > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > -- Masami HIRAMATSU Linux Technology Research Center, System Productivity Research Dept. Center for Technology Innovation - Systems Engineering Hitachi, Ltd., Research & Development Group E-mail: masami.hiramatsu...@hitachi.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
