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Message-ID: <20141122195926.GA1707@wfg-t540p.sh.intel.com>
Date: Sat, 22 Nov 2014 11:59:26 -0800
From: Fengguang Wu <fengguang.wu@...el.com>
To: Steven Rostedt <rostedt@...dmis.org>
Cc: LKP <lkp@...org>, linux-kernel@...r.kernel.org
Subject: Re: [ftrace/x86/extable] WARNING: CPU: 0 PID: 1 at init/main.c:803
do_one_initcall()
Hi Steven,
On Sat, Nov 22, 2014 at 02:11:39PM -0500, Steven Rostedt wrote:
> On Sat, 22 Nov 2014 10:43:49 -0800
> Fengguang Wu <fengguang.wu@...el.com> wrote:
>
> > Greetings,
> >
> > 0day kernel testing robot got the below dmesg and the first bad commit is
> >
> > git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git rfc/seq-buf
> >
> > commit 716c18f8e57c5eff4725f0b5acbdb2fead202d8c
>
> Yeah I had a brain fart with this patch that my tests quickly caught
> (which I push to my repo for your basic tests as I start testing with
> my own tests). But it wasn't up for very long before I rebased it with
> a working patch.
Sorry about that! The auto bisect was actually done in Nov 19,
unfortunately I was on travel in the past days, which lead to
the long delay in reporting out.
>
> > Author: Steven Rostedt (Red Hat) <rostedt@...dmis.org>
> > AuthorDate: Tue Nov 18 21:14:11 2014 -0500
> > Commit: Steven Rostedt <rostedt@...dmis.org>
> > CommitDate: Tue Nov 18 23:26:23 2014 -0500
>
> Is it possible for your tests to see if a branch was rebased before
> posting bug reports to LKML? This gave me a scare that my new code had
> the same brain fart in it.
Sure and good idea! I'll implement it right now.
Thanks,
Fengguang
> > ftrace/x86/extable: Add is_ftrace_trampoline() function
> >
> > Stack traces that happen from function tracing check if the address
> > on the stack is a __kernel_text_address(). That is, is the address
> > kernel code. This calls core_kernel_text() which returns true
> > if the address is part of the builtin kernel code. It also calls
> > is_module_text_address() which returns true if the address belongs
> > to module code.
> >
> > But what is missing is ftrace dynamically allocated trampolines.
> > These trampolines are allocated for individual ftrace_ops that
> > call the ftrace_ops callback functions directly. But if they do a
> > stack trace, the code checking the stack wont detect them as they
> > are neither core kernel code nor module address space.
> >
> > Adding another field to ftrace_ops that also stores the size of
> > the trampoline assigned to it we can create a new function called
> > is_ftrace_trampoline() that returns true if the address is a
> > dynamically allocate ftrace trampoline. Note, it ignores trampolines
> > that are not dynamically allocated as they will return true with
> > the core_kernel_text() function.
> >
> > Link: http://lkml.kernel.org/r/20141119034829.497125839@goodmis.org
> >
> > Cc: Thomas Gleixner <tglx@...utronix.de>
> > Cc: Ingo Molnar <mingo@...hat.com>
> > Cc: "H. Peter Anvin" <hpa@...or.com>
> > Signed-off-by: Steven Rostedt <rostedt@...dmis.org>
> >
> > +-------------------------------------------------------------------------+------------+------------+------------+
> > | | 766d21c795 | 716c18f8e5 | d165a751a0 |
> > +-------------------------------------------------------------------------+------------+------------+------------+
> > | boot_successes | 60 | 0 | 0 |
> > | boot_failures | 0 | 20 | 16 |
> > | WARNING:at_init/main.c:do_one_initcall() | 0 | 20 | 16 |
> > | initcall_init_kprobes_returned_with_preemption_imbalance | 0 | 20 | 16 |
> > | BUG:scheduling_while_atomic | 0 | 20 | 11 |
> > | BUG:workqueue_leaked_lock_or_atomic:kworker | 0 | 1 | 2 |
> > | backtrace:init_kprobes | 0 | 20 | 16 |
> > | backtrace:warn_slowpath_fmt | 0 | 20 | 16 |
> > | backtrace:kernel_init_freeable | 0 | 20 | 16 |
> > | backtrace:event_trace_self_tests | 0 | 20 | 11 |
> > | backtrace:event_trace_self_tests_init | 0 | 20 | 11 |
> > | backtrace:dump_stack | 0 | 1 | 2 |
> > | backtrace:test_work | 0 | 1 | 2 |
> > | initcall_event_trace_self_tests_init_returned_with_preemption_imbalance | 0 | 18 | 7 |
> > | backtrace:unregister_ftrace_function | 0 | 18 | 7 |
> > | BUG:kernel_boot_hang | 0 | 0 | 2 |
> > +-------------------------------------------------------------------------+------------+------------+------------+
> >
> > [ 1.649109] Kprobe smoke test: passed successfully
> > [ 1.649888] ------------[ cut here ]------------
> > [ 1.649888] ------------[ cut here ]------------
> > [ 1.650631] WARNING: CPU: 0 PID: 1 at init/main.c:803 do_one_initcall+0x1a9/0x200()
> > [ 1.650631] WARNING: CPU: 0 PID: 1 at init/main.c:803 do_one_initcall+0x1a9/0x200()
> > [ 1.652149] initcall init_kprobes+0x0/0x1d2 returned with preemption imbalance
> > [ 1.652149] initcall init_kprobes+0x0/0x1d2 returned with preemption imbalance
> > [ 1.653357] Modules linked in:
> > [ 1.653357] Modules linked in:
> >
> > [ 1.653857] CPU: 0 PID: 1 Comm: swapper Not tainted 3.18.0-rc1-00020-g716c18f #58
> > [ 1.653857] CPU: 0 PID: 1 Comm: swapper Not tainted 3.18.0-rc1-00020-g716c18f #58
> > [ 1.655071] 0000000000000009
> > [ 1.655071] 0000000000000009 ffff88001345fdf8 ffff88001345fdf8 ffffffff816356b2 ffffffff816356b2 ffff88001345fe38 ffff88001345fe38
> >
> > [ 1.656312] ffffffff8108da6a
> > [ 1.656312] ffffffff8108da6a ffff88001345fe58 ffff88001345fe58 0000000000000000 0000000000000000 0000000000000001 0000000000000001
> >
> > [ 1.657542] 0000000000000001
> > [ 1.657542] 0000000000000001 ffffffff81f09df6 ffffffff81f09df6 0000000000000000 0000000000000000 ffff88001345fe98 ffff88001345fe98
> >
> > [ 1.658800] Call Trace:
> > [ 1.658800] Call Trace:
> > [ 1.659200] [<ffffffff816356b2>] dump_stack+0x19/0x1b
> > [ 1.659200] [<ffffffff816356b2>] dump_stack+0x19/0x1b
> > [ 1.660020] [<ffffffff8108da6a>] warn_slowpath_common+0x7a/0xa0
> > [ 1.660020] [<ffffffff8108da6a>] warn_slowpath_common+0x7a/0xa0
> > [ 1.660991] [<ffffffff81f09df6>] ? debugfs_kprobe_init+0xab/0xab
> > [ 1.660991] [<ffffffff81f09df6>] ? debugfs_kprobe_init+0xab/0xab
> > [ 1.661994] [<ffffffff8108dad6>] warn_slowpath_fmt+0x46/0x50
> > [ 1.661994] [<ffffffff8108dad6>] warn_slowpath_fmt+0x46/0x50
> > [ 1.662900] [<ffffffff81f09fbf>] ? init_kprobes+0x1c9/0x1d2
> > [ 1.662900] [<ffffffff81f09fbf>] ? init_kprobes+0x1c9/0x1d2
> > [ 1.663810] [<ffffffff81f09df6>] ? debugfs_kprobe_init+0xab/0xab
> > [ 1.663810] [<ffffffff81f09df6>] ? debugfs_kprobe_init+0xab/0xab
> > [ 1.665184] [<ffffffff810003c9>] do_one_initcall+0x1a9/0x200
> > [ 1.665184] [<ffffffff810003c9>] do_one_initcall+0x1a9/0x200
> > [ 1.666615] [<ffffffff81ef10f1>] kernel_init_freeable+0x102/0x185
> > [ 1.666615] [<ffffffff81ef10f1>] kernel_init_freeable+0x102/0x185
> > [ 1.668170] [<ffffffff81631e90>] ? rest_init+0xd0/0xd0
> > [ 1.668170] [<ffffffff81631e90>] ? rest_init+0xd0/0xd0
> > [ 1.669476] [<ffffffff81631e9e>] kernel_init+0xe/0xf0
> > [ 1.669476] [<ffffffff81631e9e>] kernel_init+0xe/0xf0
> > [ 1.670763] [<ffffffff8163d77a>] ret_from_fork+0x7a/0xb0
> > [ 1.670763] [<ffffffff8163d77a>] ret_from_fork+0x7a/0xb0
> > [ 1.672123] [<ffffffff81631e90>] ? rest_init+0xd0/0xd0
> > [ 1.672123] [<ffffffff81631e90>] ? rest_init+0xd0/0xd0
> > [ 1.673365] ---[ end trace 660d24cf53fa6caf ]---
> > [ 1.673365] ---[ end trace 660d24cf53fa6caf ]---
> >
> > git bisect start d165a751a05de3cd926f1378b0df3de3b7cab051 fc14f9c1272f62c3e8d01300f52467c0d9af50f9 --
> > git bisect bad 36e2c5fccd02b60b6e98f08aa61d33f43188fb08 # 16:03 0- 15 Merge 'jlayton/nfsd-3.20' into devel-lkp-ib04-smoke-201411191439
> > git bisect bad 847d1c3e2f2d8703f63b73420eb7a46c26f54e9b # 16:35 0- 17 Merge 'shawnguo/imx/soc' into devel-lkp-ib04-smoke-201411191439
> > git bisect bad d4620f93d2a5011fe43d5de0ac8c8fd670b00705 # 17:19 0- 16 Merge 'pm/bleeding-edge' into devel-lkp-ib04-smoke-201411191439
> > git bisect good d5b06eebb3c327b5ae53d4a80aa4a8061a8ba125 # 17:41 20+ 0 0day base guard for 'devel-lkp-ib04-smoke-201411191439'
> > git bisect bad 5bc53bc9b7a94d183337b5233472a2480abbc655 # 18:36 0- 16 Merge 'trace/rfc/seq-buf' into devel-lkp-ib04-smoke-201411191439
> > git bisect bad c965f1fce4bc52abaaea95113a50c97b183b311e # 19:39 0- 17 blktrace/tracing: Use trace_seq_has_overflowed() helper function
> > git bisect good 8520dedbbf7578a397ecdfcf6ab83f775f914cfe # 20:19 20+ 0 tracing: kdb: Fix kernel livelock with empty buffers
> > git bisect good a9ce7c36aa4256019180c590d60e2fad7431c749 # 20:43 20+ 0 tracing: Fix race of function probes counting
> > git bisect bad f745f25c1f01464c376b7fe82e34db08ed22f321 # 21:06 0- 2 x86/kvm/tracing: Use helper function trace_seq_buffer_ptr()
> > git bisect bad 716c18f8e57c5eff4725f0b5acbdb2fead202d8c # 21:23 0- 20 ftrace/x86/extable: Add is_ftrace_trampoline() function
> > git bisect good 766d21c7953e3b02699183309d997b1c2cd9e0bb # 22:32 20+ 0 ftrace/x86: Add frames pointers to trampoline as necessary
> > # first bad commit: [716c18f8e57c5eff4725f0b5acbdb2fead202d8c] ftrace/x86/extable: Add is_ftrace_trampoline() function
> > git bisect good 766d21c7953e3b02699183309d997b1c2cd9e0bb # 22:36 60+ 0 ftrace/x86: Add frames pointers to trampoline as necessary
> > git bisect bad d165a751a05de3cd926f1378b0df3de3b7cab051 # 22:36 0- 16 0day head guard for 'devel-lkp-ib04-smoke-201411191439'
> > git bisect good fc14f9c1272f62c3e8d01300f52467c0d9af50f9 # 22:39 60+ 2 Linux 3.18-rc5
> > git bisect good fad15b648058ee5ea4b352888afa9030e0092f1b # 23:18 60+ 0 Add linux-next specific files for 20141118
> >
> >
> > This script may reproduce the error.
> >
> > ----------------------------------------------------------------------------
> > #!/bin/bash
> >
> > kernel=$1
> > initrd=yocto-minimal-x86_64.cgz
> >
> > wget --no-clobber https://github.com/fengguang/reproduce-kernel-bug/raw/master/initrd/$initrd
> >
> > kvm=(
> > qemu-system-x86_64
> > -cpu kvm64
> > -enable-kvm
> > -kernel $kernel
> > -initrd $initrd
> > -m 320
> > -smp 1
> > -net nic,vlan=1,model=e1000
> > -net user,vlan=1
> > -boot order=nc
> > -no-reboot
> > -watchdog i6300esb
> > -rtc base=localtime
> > -serial stdio
> > -display none
> > -monitor null
> > )
> >
> > append=(
> > hung_task_panic=1
> > earlyprintk=ttyS0,115200
> > debug
> > apic=debug
> > sysrq_always_enabled
> > rcupdate.rcu_cpu_stall_timeout=100
> > panic=-1
> > softlockup_panic=1
> > nmi_watchdog=panic
> > oops=panic
> > load_ramdisk=2
> > prompt_ramdisk=0
> > console=ttyS0,115200
> > console=tty0
> > vga=normal
> > root=/dev/ram0
> > rw
> > drbd.minor_count=8
> > )
> >
> > "${kvm[@]}" --append "${append[*]}"
> > ----------------------------------------------------------------------------
> >
> > Thanks,
> > Fengguang
--
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