Re: [jump_label_test] WARNING: CPU: 0 PID: 1 at kernel/jump_label.c:761 jump_label_test+0x63/0xab

["Paul E. McKenney" <paulmck@linux.vnet.ibm.com>]

On Fri, Nov 10, 2017 at 04:32:45PM -0500, Jason Baron wrote:
> 
> On 11/09/2017 03:56 PM, Paul E. McKenney wrote:
> > On Thu, Nov 09, 2017 at 03:13:24PM -0500, Jason Baron wrote:
> >> On 11/08/2017 02:01 AM, Fengguang Wu wrote:
> >>> On Tue, Nov 07, 2017 at 05:17:38PM -0500, Jason Baron wrote:
> >>>>
> >>>>
> >>>> On 11/07/2017 04:27 AM, Fengguang Wu wrote:
> >>>>> Hello,
> >>>>>
> >>>>> FYI this happens in v4.14-rc8 -- it's not necessarily a new bug.
> >>>>>
> >>>>
> >>>> Hi,
> >>>>
> >>>> So this looks like the branches aren't getting updated because the
> >>>> WARN_ON()s are all from the second half of the test loop (where we
> >>>> actually change the branch direction).
> >>>>
> >>>> I ran a kernel with a very similar .config on qemu-kvm/i386 as well, and
> >>>> was not able to trigger the WARN_ON(). Do you know if it happens on
> >>>> every boot or if there is some boot timing involved?
> >>>>
> >>>> You could try the patch below, to start to narrow down if this is a
> >>>> problem with jump table setup or with the update process.
> >>>
> >>> The problem disappears after this patch.
> >>>
> >>
> >> Ok, I can reproduce the issue if I enable CONFIG_RCU_PERF_TEST and add
> >> something like the following to the command-line: "rcuperf.shutdown=1
> >> rcuperf.holdoff=2".
> > 
> > Just to be clear, this combination of parameters says to start the test
> > -after- shutting down the system, which should not be expected to do
> > anything useful.
> > 
> >> The issue is that the core jump label code uses kernel_text_address() to
> >> ensure that it does not update branches in '__init' text after it has
> >> been freed. The check uses 'system_state' variable from
> >> core_kernel_text() to make the determination:
> >>
> >>         if (system_state < SYSTEM_RUNNING &&
> >>
> >>             init_kernel_text(addr))
> >>
> >>                 return 1;
> >>
> >>         return 0;
> >>
> >> So the general idea is that system_state is set to SYSTEM_RUNNING after
> >> the __init text sections are freed, and thus we avoid updating jump
> >> label branches.
> >>
> >> However, in the case that rcuperf is enabled, it will call
> >> kernel_power_off() which in turn sets system_state to SYSTEM_POWER_OFF
> >> (which is > SYSTEM_RUNNING), potentially before the the initcalls have
> >> even been run. In this case, the jump label selftests called from __init
> >> via a late_initcall() can not update the branch direction, and thus we
> >> get the above warnings (due to the fact that the branches don't get
> >> udpated).
> >>
> >> So this is really not a new issue and really is only triggered in a
> >> debug setup, so I don't think this is 4.14 material in any way...
> >>
> >> One way to clean this up is to add a call into the jump label code
> >> similar to what ftrace does in ftrace_free_init_mem(). This gets called
> >> after the initcalls have run but before they are freed. Something like
> >> below.
> > 
> > Alternatively, rcuperf (and rcutorture and locktorture) could refused
> > to power off the system until the system state reaches SYSTEM_RUNNING.
> 
> Indeed, I think this may make more sense since there may be other code
> that depends on SYSTEM_POWER_OFF state coming after SYSTEM_RUNNING. So
> if you are ok with this, I can prepare that change instead.

Please feel free to send a patch.  Ah, one alternative would be
to make kernel_power_off() do the check.  Or maybe better yet,
kernel_shutdown_prepare().

							Thanx, Paul

> Thanks,
> 
> -Jason
> 
> 
> > That said, I am quite happy to have it fixed elsewhere.  ;-)
> > 
> > 							Thanx, Paul
> > 
> >> Thanks,
> >>
> >> -Jason
> >>
> >> diff --git a/include/linux/jump_label.h b/include/linux/jump_label.h
> >> index 3b7675b..0202c58 100644
> >> --- a/include/linux/jump_label.h
> >> +++ b/include/linux/jump_label.h
> >> @@ -158,6 +158,7 @@ extern void arch_jump_label_transform(struct
> >> jump_entry *entry,
> >>  extern void arch_jump_label_transform_static(struct jump_entry *entry,
> >>                                              enum jump_label_type type);
> >>  extern int jump_label_text_reserved(void *start, void *end);
> >> +extern void jump_label_invalidate_init(struct module *mod);
> >>  extern void static_key_slow_inc(struct static_key *key);
> >>  extern void static_key_slow_dec(struct static_key *key);
> >>  extern void jump_label_apply_nops(struct module *mod);
> >> @@ -235,6 +236,8 @@ static inline int jump_label_apply_nops(struct
> >> module *mod)
> >>         return 0;
> >>  }
> >>
> >> +static inline void jump_label_invalidate_init(struct module *mod) {}
> >> +
> >>  static inline void static_key_enable(struct static_key *key)
> >>  {
> >>         STATIC_KEY_CHECK_USE();
> >> diff --git a/include/linux/kernel.h b/include/linux/kernel.h
> >> index 4b484ab..23e3cba 100644
> >> --- a/include/linux/kernel.h
> >> +++ b/include/linux/kernel.h
> >> @@ -471,6 +471,7 @@ extern unsigned long long memparse(const char *ptr,
> >> char **retptr);
> >>  extern bool parse_option_str(const char *str, const char *option);
> >>  extern char *next_arg(char *args, char **param, char **val);
> >>
> >> +extern int init_kernel_text(unsigned long addr);
> >>  extern int core_kernel_text(unsigned long addr);
> >>  extern int core_kernel_data(unsigned long addr);
> >>  extern int __kernel_text_address(unsigned long addr);
> >> diff --git a/init/main.c b/init/main.c
> >> index 0ee9c686..f4e5ab5 100644
> >> --- a/init/main.c
> >> +++ b/init/main.c
> >> @@ -994,6 +994,7 @@ static int __ref kernel_init(void *unused)
> >>         /* need to finish all async __init code before freeing the memory */
> >>         async_synchronize_full();
> >>         ftrace_free_init_mem();
> >> +       jump_label_invalidate_init(NULL);
> >>         free_initmem();
> >>         mark_readonly();
> >>         system_state = SYSTEM_RUNNING;
> >> diff --git a/kernel/extable.c b/kernel/extable.c
> >> index 9aa1cc4..1d69178 100644
> >> --- a/kernel/extable.c
> >> +++ b/kernel/extable.c
> >> @@ -62,7 +62,7 @@ const struct exception_table_entry
> >> *search_exception_tables(unsigned long addr)
> >>         return e;
> >>  }
> >>
> >> -static inline int init_kernel_text(unsigned long addr)
> >> +int init_kernel_text(unsigned long addr)
> >>  {
> >>         if (addr >= (unsigned long)_sinittext &&
> >>             addr < (unsigned long)_einittext)
> >> diff --git a/kernel/jump_label.c b/kernel/jump_label.c
> >> index 0bf2e8f5..3f804f4 100644
> >> --- a/kernel/jump_label.c
> >> +++ b/kernel/jump_label.c
> >> @@ -359,16 +359,44 @@ static void __jump_label_update(struct static_key
> >> *key,
> >>                                 struct jump_entry *stop)
> >>  {
> >>         for (; (entry < stop) && (jump_entry_key(entry) == key); entry++) {
> >> -               /*
> >> -                * entry->code set to 0 invalidates module init text
> >> sections
> >> -                * kernel_text_address() verifies we are not in core kernel
> >> -                * init code, see jump_label_invalidate_module_init().
> >> -                */
> >> -               if (entry->code && kernel_text_address(entry->code))
> >> +               /* entry->code set to 0 invalidates __init text sections */
> >> +               if (entry->code)
> >>                         arch_jump_label_transform(entry,
> >> jump_label_type(entry));
> >>         }
> >>  }
> >>
> >> +void jump_label_invalidate_init(struct module *mod)
> >> +{
> >> +       struct jump_entry *iter_start = mod->jump_entries;
> >> +       struct jump_entry *iter_stop = iter_start + mod->num_jump_entries;
> >> +       struct jump_entry *iter;
> >> +
> >> +       if (mod) {
> >> +               iter_start = mod->jump_entries;
> >> +               iter_stop = iter_start + mod->num_jump_entries;
> >> +       } else {
> >> +               jump_label_lock();
> >> +               iter_start = __start___jump_table;
> >> +               iter_stop = __stop___jump_table;
> >> +       }
> >> +
> >> +       for (iter = iter_start; iter < iter_stop; iter++) {
> >> +               if (mod) {
> >> +                       if (!within_module_init(iter->code, mod) &&
> >> +                           !within_module_init(iter->target, mod))
> >> +                               continue;
> >> +               } else {
> >> +                       if (!init_kernel_text(iter->code) &&
> >> +                           !init_kernel_text(iter->target))
> >> +                               continue;
> >> +               }
> >> +               iter->code = 0;
> >> +       }
> >> +
> >> +       if (!mod)
> >> +               jump_label_unlock();
> >> +}
> >> +
> >>  void __init jump_label_init(void)
> >>  {
> >>         struct jump_entry *iter_start = __start___jump_table;
> >> @@ -627,18 +655,6 @@ static void jump_label_del_module(struct module *mod)
> >>         }
> >>  }
> >>
> >> -static void jump_label_invalidate_module_init(struct module *mod)
> >> -{
> >> -       struct jump_entry *iter_start = mod->jump_entries;
> >> -       struct jump_entry *iter_stop = iter_start + mod->num_jump_entries;
> >> -       struct jump_entry *iter;
> >> -
> >> -       for (iter = iter_start; iter < iter_stop; iter++) {
> >> -               if (within_module_init(iter->code, mod))
> >> -                       iter->code = 0;
> >> -       }
> >> -}
> >> -
> >>  static int
> >>  jump_label_module_notify(struct notifier_block *self, unsigned long val,
> >>                          void *data)
> >> @@ -661,7 +677,7 @@ jump_label_module_notify(struct notifier_block
> >> *self, unsigned long val,
> >>                 jump_label_del_module(mod);
> >>                 break;
> >>         case MODULE_STATE_LIVE:
> >> -               jump_label_invalidate_module_init(mod);
> >> +               jump_label_invalidate_init(mod);
> >>                 break;
> >>         }
> >>
> >>
> >>
> >>
> >>> The dmesg is now:
> >>>
> >>> [    7.342618] IRQ10 -> 0:10
> >>> [    7.343025] IRQ11 -> 0:11
> >>> [    7.343450] IRQ12 -> 0:12
> >>> [    7.343770] IRQ13 -> 0:13
> >>> [    7.344079] IRQ14 -> 0:14
> >>> [    7.344379] IRQ15 -> 0:15
> >>> [    7.344690] .................................... done.
> >>> [    7.345271] Using IPI Shortcut mode
> >>> [    7.345682] sched_clock: Marking stable (7344687295, 0)->(7595176493,
> >>> -250489198)
> >>> [    7.346516] __jump_label_update: key: 0xcd3a0dec, code: 0xcca65b30,
> >>> target: 0xcca65b40
> >>> [    7.347600] __jump_label_update: key: 0xcd3a0dec, code: 0xcca65999,
> >>> target: 0xcca659b8
> >>> [    7.349195] __jump_label_update: key: 0xcd3a0dec, code: 0xcca65c50,
> >>> target: 0xcca65c9a
> >>> [    7.350075] __jump_label_update: key: 0xcd3a0dec, code: 0xcca65bf0,
> >>> target: 0xcca65bf8
> >>> [    7.350963] __jump_label_update: key: 0xcd3a0dec, code: 0xcca65b90,
> >>> target: 0xcca65b98
> >>> [    7.351848] __jump_label_update: key: 0xcd3a0dec, code: 0xcca65b68,
> >>> target: 0xcca65b63
> >>> [    7.353000] jump_label: disable sk_true: cd2adc60
> >>> [    7.353668] __jump_label_update: key: 0xcd2adc60, code: 0xcd31ae3c,
> >>> target: 0xcd31ae9d
> >>> [    7.354852] __jump_label_update: key: 0xcd2adc60, code: 0xcd31add7,
> >>> target: 0xcd31adde
> >>> [    7.356021] __jump_label_update: key: 0xcd2adc60, code: 0xcd31ae35,
> >>> target: 0xcd31ae3c
> >>> [    7.357023] __jump_label_update: key: 0xcd2adc60, code: 0xcd31add2,
> >>> target: 0xcd31ae8f
> >>> [    7.357970] jump_label: enable sk_false: cda8ef5c
> >>> [    7.358682] __jump_label_update: key: 0xcda8ef5c, code: 0xcd31ae46,
> >>> target: 0xcd31ae4d
> >>> [    7.359858] __jump_label_update: key: 0xcda8ef5c, code: 0xcd31ade5,
> >>> target: 0xcd31ae96
> >>> [    7.361049] __jump_label_update: key: 0xcda8ef5c, code: 0xcd31ae41,
> >>> target: 0xcd31aea1
> >>> [    7.362235] __jump_label_update: key: 0xcda8ef5c, code: 0xcd31adde,
> >>> target: 0xcd31ade5
> >>> [    7.363408] jump_label: enable sk_true: cd2adc60
> >>> [    7.364100] __jump_label_update: key: 0xcd2adc60, code: 0xcd31ae3c,
> >>> target: 0xcd31ae9d
> >>> [    7.365282] __jump_label_update: key: 0xcd2adc60, code: 0xcd31add7,
> >>> target: 0xcd31adde
> >>> [    7.366465] __jump_label_update: key: 0xcd2adc60, code: 0xcd31ae35,
> >>> target: 0xcd31ae3c
> >>> [    7.367639] __jump_label_update: key: 0xcd2adc60, code: 0xcd31add2,
> >>> target: 0xcd31ae8f
> >>> [    7.368818] jump_label: disable sk_false: cda8ef5c
> >>> [    7.369538] __jump_label_update: key: 0xcda8ef5c, code: 0xcd31ae46,
> >>> target: 0xcd31ae4d
> >>> [    7.370716] __jump_label_update: key: 0xcda8ef5c, code: 0xcd31ade5,
> >>> target: 0xcd31ae96
> >>> [    7.371900] __jump_label_update: key: 0xcda8ef5c, code: 0xcd31ae41,
> >>> target: 0xcd31aea1
> >>> [    7.373087] __jump_label_update: key: 0xcda8ef5c, code: 0xcd31adde,
> >>> target: 0xcd31ade5
> >>> [    7.374275] jump_label: disable sk_true: cd2adc60
> >>> [    7.374991] __jump_label_update: key: 0xcd2adc60, code: 0xcd31ae3c,
> >>> target: 0xcd31ae9d
> >>> [    7.376175] __jump_label_update: key: 0xcd2adc60, code: 0xcd31add7,
> >>> target: 0xcd31adde
> >>> [    7.377368] __jump_label_update: key: 0xcd2adc60, code: 0xcd31ae35,
> >>> target: 0xcd31ae3c
> >>> [    7.378565] __jump_label_update: key: 0xcd2adc60, code: 0xcd31add2,
> >>> target: 0xcd31ae8f
> >>> [    7.379750] jump_label: enable sk_false: cda8ef5c
> >>> [    7.380459] __jump_label_update: key: 0xcda8ef5c, code: 0xcd31ae46,
> >>> target: 0xcd31ae4d
> >>> [    7.381654] __jump_label_update: key: 0xcda8ef5c, code: 0xcd31ade5,
> >>> target: 0xcd31ae96
> >>> [    7.382855] __jump_label_update: key: 0xcda8ef5c, code: 0xcd31ae41,
> >>> target: 0xcd31aea1
> >>> [    7.384046] __jump_label_update: key: 0xcda8ef5c, code: 0xcd31adde,
> >>> target: 0xcd31ade5
> >>> [    7.385243] jump_label: enable sk_true: cd2adc60
> >>> [    7.385944] __jump_label_update: key: 0xcd2adc60, code: 0xcd31ae3c,
> >>> target: 0xcd31ae9d
> >>> [    7.387109] __jump_label_update: key: 0xcd2adc60, code: 0xcd31add7,
> >>> target: 0xcd31adde
> >>> [    7.388276] __jump_label_update: key: 0xcd2adc60, code: 0xcd31ae35,
> >>> target: 0xcd31ae3c
> >>> [    7.389449] __jump_label_update: key: 0xcd2adc60, code: 0xcd31add2,
> >>> target: 0xcd31ae8f
> >>> [    7.390621] jump_label: disable sk_false: cda8ef5c
> >>> [    7.391337] __jump_label_update: key: 0xcda8ef5c, code: 0xcd31ae46,
> >>> target: 0xcd31ae4d
> >>> [    7.392509] __jump_label_update: key: 0xcda8ef5c, code: 0xcd31ade5,
> >>> target: 0xcd31ae96
> >>> [    7.393973] __jump_label_update: key: 0xcda8ef5c, code: 0xcd31ae41,
> >>> target: 0xcd31aea1
> >>> [    7.395025] __jump_label_update: key: 0xcda8ef5c, code: 0xcd31adde,
> >>> target: 0xcd31ade5
> >>> [    7.398024] debug: unmapping init [mem 0xcd305000-0xcd38ffff]
> >>> [    7.398757] Write protecting the kernel text: 5796k
> >>> [    7.399449] Write protecting the kernel read-only data: 2736k
> >>>
> >>> Thanks,
> >>> Fengguang
> >>>
> >>>> Thanks,
> >>>>
> >>>> -Jason
> >>>>
> >>>>
> >>>> diff --git a/kernel/jump_label.c b/kernel/jump_label.c
> >>>> index 0bf2e8f5..433cc94 100644
> >>>> --- a/kernel/jump_label.c
> >>>> +++ b/kernel/jump_label.c
> >>>> @@ -364,8 +364,13 @@ static void __jump_label_update(struct static_key
> >>>> *key,
> >>>>                 * kernel_text_address() verifies we are not in core
> >>>> kernel
> >>>>                 * init code, see jump_label_invalidate_module_init().
> >>>>                 */
> >>>> -               if (entry->code && kernel_text_address(entry->code))
> >>>> +               if (entry->code && kernel_text_address(entry->code)) {
> >>>> +                       printk("%s: key: 0x%lx, code: 0x%lx, target:
> >>>> 0x%lx\n",
> >>>> +                              __func__, (unsigned
> >>>> long)jump_entry_key(entry),
> >>>> +                              (unsigned long)entry->code,
> >>>> +                              (unsigned long)entry->target);
> >>>>                        arch_jump_label_transform(entry,
> >>>> jump_label_type(entry));
> >>>> +               }
> >>>>        }
> >>>> }
> >>>>
> >>>> @@ -752,7 +757,9 @@ static __init int jump_label_test(void)
> >>>>                WARN_ON(static_branch_likely(&sk_false));
> >>>>                WARN_ON(static_branch_unlikely(&sk_false));
> >>>>
> >>>> +               printk("jump_label: disable sk_true: %p\n", &sk_true);
> >>>>                static_branch_disable(&sk_true);
> >>>> +               printk("jump_label: enable sk_false: %p\n", &sk_false);
> >>>>                static_branch_enable(&sk_false);
> >>>>
> >>>>                WARN_ON(static_key_enabled(&sk_true.key) == true);
> >>>> @@ -763,7 +770,9 @@ static __init int jump_label_test(void)
> >>>>                WARN_ON(!static_branch_likely(&sk_false));
> >>>>                WARN_ON(!static_branch_unlikely(&sk_false));
> >>>>
> >>>> +               printk("jump_label: enable sk_true: %p\n", &sk_true);
> >>>>                static_branch_enable(&sk_true);
> >>>> +               printk("jump_label: disable sk_false: %p\n", &sk_false);
> >>>>                static_branch_disable(&sk_false);
> >>>>        }
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>> [   15.214834] IRQ15 -> 0:15
> >>>>> [   15.214834] .................................... done.
> >>>>> [   15.214834] Using IPI Shortcut mode
> >>>>> [   15.214834] sched_clock: Marking stable (15210834346,
> >>>>> 0)->(15797181340, -586346994)
> >>>>> [   17.667168] ------------[ cut here ]------------
> >>>>> [   17.668895] WARNING: CPU: 0 PID: 1 at kernel/jump_label.c:761
> >>>>> jump_label_test+0x63/0xab
> >>>>> [   17.672346] Modules linked in:
> >>>>> [   17.673475] CPU: 0 PID: 1 Comm: swapper Not tainted 4.14.0-rc8 #29
> >>>>> [   17.675724] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
> >>>>> BIOS 1.10.2-1 04/01/2014
> >>>>> [   17.678755] task: c0020d00 task.stack: c0022000
> >>>>> [   17.680423] EIP: jump_label_test+0x63/0xab
> >>>>> [   17.681912] EFLAGS: 00210202 CPU: 0
> >>>>> [   17.683206] EAX: 00000001 EBX: 00000002 ECX: 00000004 EDX: 00000000
> >>>>> [   17.685501] ESI: c9918db6 EDI: 00000000 EBP: 00000000 ESP: c0023f40
> >>>>> [   17.687787]  DS: 007b ES: 007b FS: 0000 GS: 0000 SS: 0068
> >>>>> [   17.689748] CR0: 80050033 CR2: 00000000 CR3: 09991000 CR4: 000006b0
> >>>>> [   17.692019] Call Trace:
> >>>>> [   17.692938]  ? do_one_initcall+0x2c/0x13a
> >>>>> [   17.694398]  ? parse_args+0x1af/0x300
> >>>>> [   17.695740]  ? kernel_init_freeable+0xce/0x161
> >>>>> [   17.697370]  ? kernel_init_freeable+0xee/0x161
> >>>>> [   17.698986]  ? rest_init+0xb0/0xb0
> >>>>> [   17.700236]  ? kernel_init+0x5/0xe0
> >>>>> [   17.701513]  ? ret_from_fork+0x19/0x30
> >>>>> [   17.702876] Code: c9 e8 3c 59 7b ff b8 5c cf 08 ca e8 a2 58 7b ff
> >>>>> a1 60 bc 8a c9 85 c0 74 02 0f ff a1 5c cf 08 ca 85 c0 75 02 0f ff 3e
> >>>>> 8d 74 26 00 <0f> ff e9 35 00 00 00 e9 34 00 00 00 3e 8d 74 26 00 0f
> >>>>> ff b8 60
> >>>>> [   17.709721] ---[ end trace f18711bfa2b1114e ]---
> >>>>> [   17.711418] ------------[ cut here ]------------
> >>>>> [   17.711418] ------------[ cut here ]------------
> >>>>> [   17.713092] WARNING: CPU: 0 PID: 1 at kernel/jump_label.c:762
> >>>>> jump_label_test+0x9f/0xab
> >>>>> [   17.716534] Modules linked in:
> >>>>> [   17.717665] CPU: 0 PID: 1 Comm: swapper Tainted: G        W      
> >>>>> 4.14.0-rc8 #29
> >>>>> [   17.720349] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
> >>>>> BIOS 1.10.2-1 04/01/2014
> >>>>> [   17.723362] task: c0020d00 task.stack: c0022000
> >>>>> [   17.725004] EIP: jump_label_test+0x9f/0xab
> >>>>> [   17.726516] EFLAGS: 00210202 CPU: 0
> >>>>> [   17.727785] EAX: 00000001 EBX: 00000002 ECX: 00000004 EDX: 00000000
> >>>>> [   17.730058] ESI: c9918db6 EDI: 00000000 EBP: 00000000 ESP: c0023f40
> >>>>> [   17.732341]  DS: 007b ES: 007b FS: 0000 GS: 0000 SS: 0068
> >>>>> [   17.734300] CR0: 80050033 CR2: 00000000 CR3: 09991000 CR4: 000006b0
> >>>>> [   17.736560] Call Trace:
> >>>>> [   17.737476]  ? do_one_initcall+0x2c/0x13a
> >>>>> [   17.738943]  ? parse_args+0x1af/0x300
> >>>>> [   17.740326]  ? kernel_init_freeable+0xce/0x161
> >>>>> [   17.741943]  ? kernel_init_freeable+0xee/0x161
> >>>>> [   17.743571]  ? rest_init+0xb0/0xb0
> >>>>> [   17.744820]  ? kernel_init+0x5/0xe0
> >>>>> [   17.746095]  ? ret_from_fork+0x19/0x30
> >>>>> [   17.747474] Code: 0f ff b8 60 bc 8a c9 e8 6a 58 7b ff b8 5c cf 08
> >>>>> ca e8 f0 58 7b ff 4b 74 1a bb 01 00 00 00 e9 6f ff ff ff 0f ff eb 86
> >>>>> 0f ff eb 95 <0f> ff eb c7 0f ff eb c8 31 c0 5b c3 b8 68 bc 8a c9 e9
> >>>>> 25 d4 77
> >>>>> [   17.754356] ---[ end trace f18711bfa2b1114f ]---
> >>>>> [   17.755649] ------------[ cut here ]------------
> >>>>> [   17.755649] ------------[ cut here ]------------
> >>>>> [   17.756863] WARNING: CPU: 0 PID: 1 at kernel/jump_label.c:763
> >>>>> jump_label_test+0xa3/0xab
> >>>>> [   17.759289] Modules linked in:
> >>>>> [   17.760082] CPU: 0 PID: 1 Comm: swapper Tainted: G        W      
> >>>>> 4.14.0-rc8 #29
> >>>>> [   17.761983] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
> >>>>> BIOS 1.10.2-1 04/01/2014
> >>>>> [   17.764723] task: c0020d00 task.stack: c0022000
> >>>>> [   17.766378] EIP: jump_label_test+0xa3/0xab
> >>>>> [   17.767470] EFLAGS: 00210202 CPU: 0
> >>>>> [   17.769223] EAX: 00000001 EBX: 00000002 ECX: 00000004 EDX: 00000000
> >>>>> [   17.771188] ESI: c9918db6 EDI: 00000000 EBP: 00000000 ESP: c0023f40
> >>>>> [   17.773495]  DS: 007b ES: 007b FS: 0000 GS: 0000 SS: 0068
> >>>>> [   17.774916] CR0: 80050033 CR2: 00000000 CR3: 09991000 CR4: 000006b0
> >>>>> [   17.776576] Call Trace:
> >>>>> [   17.777249]  ? do_one_initcall+0x2c/0x13a
> >>>>> [   17.778318]  ? parse_args+0x1af/0x300
> >>>>> [   17.779292]  ? kernel_init_freeable+0xce/0x161
> >>>>> [   17.780443]  ? kernel_init_freeable+0xee/0x161
> >>>>> [   17.781558]  ? rest_init+0xb0/0xb0
> >>>>> [   17.782463]  ? kernel_init+0x5/0xe0
> >>>>> [   17.783394]  ? ret_from_fork+0x19/0x30
> >>>>> [   17.784376] Code: bc 8a c9 e8 6a 58 7b ff b8 5c cf 08 ca e8 f0 58
> >>>>> 7b ff 4b 74 1a bb 01 00 00 00 e9 6f ff ff ff 0f ff eb 86 0f ff eb 95
> >>>>> 0f ff eb c7 <0f> ff eb c8 31 c0 5b c3 b8 68 bc 8a c9 e9 25 d4 77 ff
> >>>>> 80 3d a0
> >>>>> [   17.789290] ---[ end trace f18711bfa2b11150 ]---
> >>>>> [   17.790487] ------------[ cut here ]------------
> >>>>> [   17.790487] ------------[ cut here ]------------
> >>>>> [   17.792555] WARNING: CPU: 0 PID: 1 at kernel/jump_label.c:764
> >>>>> jump_label_test+0x74/0xab
> >>>>> [   17.796930] Modules linked in:
> >>>>> [   17.798391] CPU: 0 PID: 1 Comm: swapper Tainted: G        W      
> >>>>> 4.14.0-rc8 #29
> >>>>> [   17.801754] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
> >>>>> BIOS 1.10.2-1 04/01/2014
> >>>>> [   17.805496] task: c0020d00 task.stack: c0022000
> >>>>> [   17.806702] EIP: jump_label_test+0x74/0xab
> >>>>> [   17.807786] EFLAGS: 00210202 CPU: 0
> >>>>> [   17.808726] EAX: 00000001 EBX: 00000002 ECX: 00000004 EDX: 00000000
> >>>>> [   17.810368] ESI: c9918db6 EDI: 00000000 EBP: 00000000 ESP: c0023f40
> >>>>> [   17.811994]  DS: 007b ES: 007b FS: 0000 GS: 0000 SS: 0068
> >>>>> [   17.813424] CR0: 80050033 CR2: 00000000 CR3: 09991000 CR4: 000006b0
> >>>>> [   17.815063] Call Trace:
> >>>>> [   17.815748]  ? do_one_initcall+0x2c/0x13a
> >>>>> [   17.816822]  ? parse_args+0x1af/0x300
> >>>>> [   17.817812]  ? kernel_init_freeable+0xce/0x161
> >>>>> [   17.818986]  ? kernel_init_freeable+0xee/0x161
> >>>>> [   17.820172]  ? rest_init+0xb0/0xb0
> >>>>> [   17.821081]  ? kernel_init+0x5/0xe0
> >>>>> [   17.822033]  ? ret_from_fork+0x19/0x30
> >>>>> [   17.823051] Code: 60 bc 8a c9 85 c0 74 02 0f ff a1 5c cf 08 ca 85
> >>>>> c0 75 02 0f ff 3e 8d 74 26 00 0f ff e9 35 00 00 00 e9 34 00 00 00 3e
> >>>>> 8d 74 26 00 <0f> ff b8 60 bc 8a c9 e8 6a 58 7b ff b8 5c cf 08 ca e8
> >>>>> f0 58 7b
> >>>>> [   17.828103] ---[ end trace f18711bfa2b11151 ]---
> >>>>> [   17.829379] ------------[ cut here ]------------
> >>>>> [   17.829379] ------------[ cut here ]------------
> >>>>> [   17.830622] WARNING: CPU: 0 PID: 1 at kernel/jump_label.c:761
> >>>>> jump_label_test+0x63/0xab
> >>>>> [   17.833131] Modules linked in:
> >>>>> [   17.833973] CPU: 0 PID: 1 Comm: swapper Tainted: G        W      
> >>>>> 4.14.0-rc8 #29
> >>>>> [   17.835923] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
> >>>>> BIOS 1.10.2-1 04/01/2014
> >>>>> [   17.838126] task: c0020d00 task.stack: c0022000
> >>>>> [   17.839355] EIP: jump_label_test+0x63/0xab
> >>>>> [   17.840447] EFLAGS: 00210202 CPU: 0
> >>>>> [   17.841384] EAX: 00000001 EBX: 00000001 ECX: 00000004 EDX: 00000000
> >>>>> [   17.843034] ESI: c9918db6 EDI: 00000000 EBP: 00000000 ESP: c0023f40
> >>>>> [   17.844698]  DS: 007b ES: 007b FS: 0000 GS: 0000 SS: 0068
> >>>>> [   17.846127] CR0: 80050033 CR2: 00000000 CR3: 09991000 CR4: 000006b0
> >>>>> [   17.847794] Call Trace:
> >>>>> [   17.848472]  ? do_one_initcall+0x2c/0x13a
> >>>>> [   17.849547]  ? parse_args+0x1af/0x300
> >>>>> [   17.850590]  ? kernel_init_freeable+0xce/0x161
> >>>>> [   17.851783]  ? kernel_init_freeable+0xee/0x161
> >>>>> [   17.852977]  ? rest_init+0xb0/0xb0
> >>>>> [   17.854277]  ? kernel_init+0x5/0xe0
> >>>>> [   17.855571]  ? ret_from_fork+0x19/0x30
> >>>>> [   17.856955] Code: c9 e8 3c 59 7b ff b8 5c cf 08 ca e8 a2 58 7b ff
> >>>>> a1 60 bc 8a c9 85 c0 74 02 0f ff a1 5c cf 08 ca 85 c0 75 02 0f ff 3e
> >>>>> 8d 74 26 00 <0f> ff e9 35 00 00 00 e9 34 00 00 00 3e 8d 74 26 00 0f
> >>>>> ff b8 60
> >>>>> [   17.863904] ---[ end trace f18711bfa2b11152 ]---
> >>>>> [   17.865629] ------------[ cut here ]------------
> >>>>> [   17.865629] ------------[ cut here ]------------
> >>>>> [   17.867438] WARNING: CPU: 0 PID: 1 at kernel/jump_label.c:762
> >>>>> jump_label_test+0x9f/0xab
> >>>>> [   17.871148] Modules linked in:
> >>>>> [   17.872450] CPU: 0 PID: 1 Comm: swapper Tainted: G        W      
> >>>>> 4.14.0-rc8 #29
> >>>>> [   17.875124] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
> >>>>> BIOS 1.10.2-1 04/01/2014
> >>>>> [   17.878364] task: c0020d00 task.stack: c0022000
> >>>>> [   17.880027] EIP: jump_label_test+0x9f/0xab
> >>>>> [   17.881544] EFLAGS: 00210202 CPU: 0
> >>>>> [   17.882901] EAX: 00000001 EBX: 00000001 ECX: 00000004 EDX: 00000000
> >>>>> [   17.885473] ESI: c9918db6 EDI: 00000000 EBP: 00000000 ESP: c0023f40
> >>>>> [   17.887934]  DS: 007b ES: 007b FS: 0000 GS: 0000 SS: 0068
> >>>>> [   17.890009] CR0: 80050033 CR2: 00000000 CR3: 09991000 CR4: 000006b0
> >>>>> [   17.892339] Call Trace:
> >>>>> [   17.893316]  ? do_one_initcall+0x2c/0x13a
> >>>>> [   17.894822]  ? parse_args+0x1af/0x300
> >>>>> [   17.896911]  ? kernel_init_freeable+0xce/0x161
> >>>>> [   17.899626]  ? kernel_init_freeable+0xee/0x161
> >>>>> [   17.902732]  ? rest_init+0xb0/0xb0
> >>>>> [   17.904894]  ? kernel_init+0x5/0xe0
> >>>>> [   17.907031]  ? ret_from_fork+0x19/0x30
> >>>>> [   17.909383] Code: 0f ff b8 60 bc 8a c9 e8 6a 58 7b ff b8 5c cf 08
> >>>>> ca e8 f0 58 7b ff 4b 74 1a bb 01 00 00 00 e9 6f ff ff ff 0f ff eb 86
> >>>>> 0f ff eb 95 <0f> ff eb c7 0f ff eb c8 31 c0 5b c3 b8 68 bc 8a c9 e9
> >>>>> 25 d4 77
> >>>>> [   17.928301] ---[ end trace f18711bfa2b11153 ]---
> >>>>> [   17.931515] ------------[ cut here ]------------
> >>>>> [   17.931515] ------------[ cut here ]------------
> >>>>> [   17.943868] WARNING: CPU: 0 PID: 1 at kernel/jump_label.c:763
> >>>>> jump_label_test+0xa3/0xab
> >>>>> [   17.950147] Modules linked in:
> >>>>> [   17.952135] CPU: 0 PID: 1 Comm: swapper Tainted: G        W      
> >>>>> 4.14.0-rc8 #29
> >>>>> [   17.956297] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
> >>>>> BIOS 1.10.2-1 04/01/2014
> >>>>> [   17.964556] task: c0020d00 task.stack: c0022000
> >>>>> [   17.985804] EIP: jump_label_test+0xa3/0xab
> >>>>> [   17.988269] EFLAGS: 00210202 CPU: 0
> >>>>> [   17.990407] EAX: 00000001 EBX: 00000001 ECX: 00000004 EDX: 00000000
> >>>>> [   17.996820] ESI: c9918db6 EDI: 00000000 EBP: 00000000 ESP: c0023f40
> >>>>> [   18.000174]  DS: 007b ES: 007b FS: 0000 GS: 0000 SS: 0068
> >>>>> [   18.003505] CR0: 80050033 CR2: 00000000 CR3: 09991000 CR4: 000006b0
> >>>>> [   18.007251] Call Trace:
> >>>>> [   18.008897]  ? do_one_initcall+0x2c/0x13a
> >>>>> [   18.016611]  ? parse_args+0x1af/0x300
> >>>>> [   18.018854]  ? kernel_init_freeable+0xce/0x161
> >>>>> [   18.021573]  ? kernel_init_freeable+0xee/0x161
> >>>>> [   18.024418]  ? rest_init+0xb0/0xb0
> >>>>> [   18.026326]  ? kernel_init+0x5/0xe0
> >>>>> [   18.028418]  ? ret_from_fork+0x19/0x30
> >>>>> [   18.031569] Code: bc 8a c9 e8 6a 58 7b ff b8 5c cf 08 ca e8 f0 58
> >>>>> 7b ff 4b 74 1a bb 01 00 00 00 e9 6f ff ff ff 0f ff eb 86 0f ff eb 95
> >>>>> 0f ff eb c7 <0f> ff eb c8 31 c0 5b c3 b8 68 bc 8a c9 e9 25 d4 77 ff
> >>>>> 80 3d a0
> >>>>> [   18.050687] ---[ end trace f18711bfa2b11154 ]---
> >>>>> [   18.060661] ------------[ cut here ]------------
> >>>>> [   18.060661] ------------[ cut here ]------------
> >>>>> [   18.064196] WARNING: CPU: 0 PID: 1 at kernel/jump_label.c:764
> >>>>> jump_label_test+0x74/0xab
> >>>>> [   18.076475] Modules linked in:
> >>>>> [   18.083657] CPU: 0 PID: 1 Comm: swapper Tainted: G        W      
> >>>>> 4.14.0-rc8 #29
> >>>>> [   18.101662] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
> >>>>> BIOS 1.10.2-1 04/01/2014
> >>>>> [   18.109794] task: c0020d00 task.stack: c0022000
> >>>>> [   18.112995] EIP: jump_label_test+0x74/0xab
> >>>>> [   18.115714] EFLAGS: 00210202 CPU: 0
> >>>>> [   18.118265] EAX: 00000001 EBX: 00000001 ECX: 00000004 EDX: 00000000
> >>>>> [   18.125065] ESI: c9918db6 EDI: 00000000 EBP: 00000000 ESP: c0023f40
> >>>>> [   18.128653]  DS: 007b ES: 007b FS: 0000 GS: 0000 SS: 0068
> >>>>> [   18.130955] CR0: 80050033 CR2: 00000000 CR3: 09991000 CR4: 000006b0
> >>>>> [   18.136512] Call Trace:
> >>>>> [   18.137684]  ? do_one_initcall+0x2c/0x13a
> >>>>> [   18.141253]  ? parse_args+0x1af/0x300
> >>>>> [   18.143612]  ? kernel_init_freeable+0xce/0x161
> >>>>> [   18.146407]  ? kernel_init_freeable+0xee/0x161
> >>>>> [   18.149921]  ? rest_init+0xb0/0xb0
> >>>>> [   18.151599]  ? kernel_init+0x5/0xe0
> >>>>> [   18.153257]  ? ret_from_fork+0x19/0x30
> >>>>> [   18.155487] Code: 60 bc 8a c9 85 c0 74 02 0f ff a1 5c cf 08 ca 85
> >>>>> c0 75 02 0f ff 3e 8d 74 26 00 0f ff e9 35 00 00 00 e9 34 00 00 00 3e
> >>>>> 8d 74 26 00 <0f> ff b8 60 bc 8a c9 e8 6a 58 7b ff b8 5c cf 08 ca e8
> >>>>> f0 58 7b
> >>>>> [   18.167223] ---[ end trace f18711bfa2b11155 ]---
> >>>>>
> >>>>> Attached the full dmesg and kconfig.
> >>>>>
> >>>>> Thanks,
> >>>>> Fengguang
> >>>>>
> >>>>
> >>
> > 
>