From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753483AbdKIUO3 (ORCPT ); Thu, 9 Nov 2017 15:14:29 -0500 Received: from mx0a-00190b01.pphosted.com ([67.231.149.131]:56224 "EHLO mx0a-00190b01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753004AbdKIUOY (ORCPT ); Thu, 9 Nov 2017 15:14:24 -0500 Subject: Re: [jump_label_test] WARNING: CPU: 0 PID: 1 at kernel/jump_label.c:761 jump_label_test+0x63/0xab To: Fengguang Wu Cc: linux-kernel@vger.kernel.org, Linus Torvalds , Peter Zijlstra , Ingo Molnar , Marc Zyngier , Paolo Bonzini , Thomas Gleixner , Steven Rostedt , paulmck@linux.vnet.ibm.com, Josh Triplett References: <20171107092756.5gh7zpml7qz2bevb@wfg-t540p.sh.intel.com> <20171108070105.fxwqqw3jogr4gq4z@wfg-t540p.sh.intel.com> From: Jason Baron Message-ID: Date: Thu, 9 Nov 2017 15:13:24 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.4.0 MIME-Version: 1.0 In-Reply-To: <20171108070105.fxwqqw3jogr4gq4z@wfg-t540p.sh.intel.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-11-09_08:,, signatures=0 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 suspectscore=2 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1707230000 definitions=main-1711090270 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-11-09_08:,, signatures=0 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=2 phishscore=0 bulkscore=0 spamscore=0 clxscore=1011 lowpriorityscore=0 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1707230000 definitions=main-1711090270 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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". 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. 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 >>> >>