Re: [linux-next:master] [tracing] e5a4cc28a0: BUG:spinlock_bad_magic_on_CPU
From: Menglong Dong <hidden>
Date: 2025-10-02 09:54:43
Also in:
lkml, oe-lkp
On Thu, Oct 2, 2025 at 1:25 PM Masami Hiramatsu [off-list ref] wrote:
On Tue, 30 Sep 2025 14:48:27 +0800 kernel test robot [off-list ref] wrote:quoted
Hello, kernel test robot noticed "BUG:spinlock_bad_magic_on_CPU" on: commit: e5a4cc28a052369b6e56b0a9ac05d9b9d5607b06 ("tracing: fprobe: use rhltable for fprobe_ip_table") https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git master in testcase: boot config: x86_64-randconfig-072-20250929 compiler: gcc-14 test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 16G (please refer to attached dmesg/kmsg for entire log/backtrace) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot [off-list ref] | Closes: https://lore.kernel.org/oe-lkp/202509301440.be4b3631-lkp@intel.com (local) [ 30.894986][ T66] BUG: spinlock bad magic on CPU#0, modprobe/66 [ 30.896030][ T66] lock: fprobe_ip_table+0x110/0x180, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0 [ 30.898263][ T66] CPU: 0 UID: 0 PID: 66 Comm: modprobe Not tainted 6.17.0-rc6-00004-ge5a4cc28a052 #1 NONE 5e106928d64815a8c70ffa200d16301537e1528f [ 30.898799][ T66] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 30.898799][ T66] Call Trace: [ 30.898799][ T66] <TASK> [ 30.898799][ T66] show_stack (arch/x86/kernel/dumpstack.c:319) [ 30.898799][ T66] dump_stack_lvl (lib/dump_stack.c:122) [ 30.898799][ T66] dump_stack (lib/dump_stack.c:130) [ 30.898799][ T66] spin_dump (kernel/locking/spinlock_debug.c:71) [ 30.898799][ T66] do_raw_spin_lock.cold (kernel/locking/spinlock_debug.c:78 kernel/locking/spinlock_debug.c:86 kernel/locking/spinlock_debug.c:115) [ 30.898799][ T66] _raw_spin_lock (kernel/locking/spinlock.c:155) [ 30.898799][ T66] ? rhashtable_walk_enter (lib/rhashtable.c:687) [ 30.898799][ T66] rhashtable_walk_enter (lib/rhashtable.c:687) [ 30.898799][ T66] fprobe_module_callback (kernel/trace/fprobe.c:478)It seems that fprobe_module_callback() is called before initializing spinlock (in rhltable?). It should be initialized earlier. Maybe this free_module() is called before late_initcall()? static int __init fprobe_initcall(void) { rhltable_init(&fprobe_ip_table, &fprobe_rht_params); return 0; } late_initcall(fprobe_initcall);
Nice shot! I think this should be the reason. Thanks! Menglong Dong
Thank you,quoted
[ 30.898799][ T66] ? _mutex_trylock_nest_lock (kernel/locking/mutex.c:916) [ 30.898799][ T66] ? fprobe_addr_list_add+0x4a0/0x4a0 [ 30.898799][ T66] ? mutex_unlock (kernel/locking/mutex.c:537) [ 30.898799][ T66] notifier_call_chain (kernel/notifier.c:85) [ 30.898799][ T66] blocking_notifier_call_chain (kernel/notifier.c:381 kernel/notifier.c:368) [ 30.898799][ T66] do_init_module (kernel/module/main.c:3134) [ 30.898799][ T66] ? free_module (kernel/module/main.c:3011) [ 30.898799][ T66] load_module (kernel/module/main.c:3509) [ 30.898799][ T66] init_module_from_file (kernel/module/main.c:3701) [ 30.898799][ T66] ? __ia32_sys_init_module (kernel/module/main.c:3677) [ 30.898799][ T66] ? ftrace_likely_update (arch/x86/include/asm/smap.h:53 kernel/trace/trace_branch.c:223) [ 30.898799][ T66] ? do_raw_spin_unlock (kernel/locking/spinlock_debug.c:103 (discriminator 4) kernel/locking/spinlock_debug.c:141 (discriminator 4)) [ 30.898799][ T66] idempotent_init_module (kernel/module/main.c:3636 kernel/module/main.c:3714) [ 30.898799][ T66] ? tracer_hardirqs_on (kernel/trace/trace_irqsoff.c:643) [ 30.898799][ T66] ? init_module_from_file (kernel/module/main.c:3705) [ 30.898799][ T66] ? ftrace_likely_update (arch/x86/include/asm/smap.h:53 kernel/trace/trace_branch.c:223) [ 30.898799][ T66] __x64_sys_finit_module (include/linux/file.h:62 (discriminator 3) include/linux/file.h:83 (discriminator 3) kernel/module/main.c:3736 (discriminator 3) kernel/module/main.c:3723 (discriminator 3) kernel/module/main.c:3723 (discriminator 3)) [ 30.898799][ T66] x64_sys_call (arch/x86/entry/syscall_64.c:41) [ 30.898799][ T66] do_syscall_64 (arch/x86/entry/syscall_64.c:63 (discriminator 1) arch/x86/entry/syscall_64.c:94 (discriminator 1)) [ 30.898799][ T66] ? ksys_read (fs/read_write.c:705) [ 30.898799][ T66] ? vfs_write (fs/read_write.c:705) [ 30.898799][ T66] ? build_open_flags (fs/open.c:1420) [ 30.898799][ T66] ? ftrace_likely_update (arch/x86/include/asm/smap.h:53 kernel/trace/trace_branch.c:223) [ 30.898799][ T66] ? tracer_hardirqs_on (kernel/trace/trace_irqsoff.c:643) [ 30.898799][ T66] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4678) [ 30.898799][ T66] ? do_syscall_64 (arch/x86/entry/syscall_64.c:113) [ 30.898799][ T66] ? __x64_sys_openat (fs/open.c:1461) [ 30.898799][ T66] ? __x64_sys_open (fs/open.c:1461) [ 30.898799][ T66] ? ftrace_likely_update (arch/x86/include/asm/smap.h:53 kernel/trace/trace_branch.c:223) [ 30.898799][ T66] ? tracer_hardirqs_on (kernel/trace/trace_irqsoff.c:643) [ 30.898799][ T66] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4678) [ 30.898799][ T66] ? do_syscall_64 (arch/x86/entry/syscall_64.c:113) [ 30.898799][ T66] ? tracer_hardirqs_on (kernel/trace/trace_irqsoff.c:643) [ 30.898799][ T66] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4678) [ 30.898799][ T66] ? do_syscall_64 (arch/x86/entry/syscall_64.c:113) [ 30.898799][ T66] ? irqentry_exit (kernel/entry/common.c:210) [ 30.898799][ T66] ? exc_page_fault (arch/x86/mm/fault.c:1536) [ 30.898799][ T66] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) [ 30.898799][ T66] RIP: 0033:0x7f46bce10719 [ 30.898799][ T66] Code: 08 89 e8 5b 5d c3 66 2e 0f 1f 84 00 00 00 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d b7 06 0d 00 f7 d8 64 89 01 48 All code ======== 0: 08 89 e8 5b 5d c3 or %cl,-0x3ca2a418(%rcx) 6: 66 2e 0f 1f 84 00 00 cs nopw 0x0(%rax,%rax,1) d: 00 00 00 10: 90 nop 11: 48 89 f8 mov %rdi,%rax 14: 48 89 f7 mov %rsi,%rdi 17: 48 89 d6 mov %rdx,%rsi 1a: 48 89 ca mov %rcx,%rdx 1d: 4d 89 c2 mov %r8,%r10 20: 4d 89 c8 mov %r9,%r8 23: 4c 8b 4c 24 08 mov 0x8(%rsp),%r9 28: 0f 05 syscall 2a:* 48 3d 01 f0 ff ff cmp $0xfffffffffffff001,%rax <-- trapping instruction 30: 73 01 jae 0x33 32: c3 ret 33: 48 8b 0d b7 06 0d 00 mov 0xd06b7(%rip),%rcx # 0xd06f1 3a: f7 d8 neg %eax 3c: 64 89 01 mov %eax,%fs:(%rcx) 3f: 48 rex.W Code starting with the faulting instruction =========================================== 0: 48 3d 01 f0 ff ff cmp $0xfffffffffffff001,%rax 6: 73 01 jae 0x9 8: c3 ret 9: 48 8b 0d b7 06 0d 00 mov 0xd06b7(%rip),%rcx # 0xd06c7 10: f7 d8 neg %eax 12: 64 89 01 mov %eax,%fs:(%rcx) 15: 48 rex.W [ 30.898799][ T66] RSP: 002b:00007ffc679745b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000139 [ 30.898799][ T66] RAX: ffffffffffffffda RBX: 00005640c34b9160 RCX: 00007f46bce10719 [ 30.898799][ T66] RDX: 0000000000000000 RSI: 00005640aa9b74a0 RDI: 0000000000000004 [ 30.898799][ T66] RBP: 00005640aa9b74a0 R08: 0000000000000000 R09: 00005640c34ba430 [ 30.898799][ T66] R10: 0000000000000004 R11: 0000000000000246 R12: 0000000000040000 [ 30.898799][ T66] R13: 0000000000000000 R14: 00005640c34b83a0 R15: 0000000000000000 [ 30.898799][ T66] </TASK> [ 30.963748][ T66] Oops: general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] KASAN [ 30.964694][ T66] KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] [ 30.964694][ T66] CPU: 0 UID: 0 PID: 66 Comm: modprobe Not tainted 6.17.0-rc6-00004-ge5a4cc28a052 #1 NONE 5e106928d64815a8c70ffa200d16301537e1528f [ 30.964694][ T66] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 30.964694][ T66] RIP: 0010:rhashtable_walk_enter (include/linux/list.h:169 lib/rhashtable.c:688) [ 30.964694][ T66] Code: c1 ea 03 80 3c 02 00 0f 85 2b 02 00 00 4d 89 77 28 4d 8d 6e 10 48 b8 00 00 00 00 00 fc ff df 4d 8d 67 18 4c 89 ea 48 c1 ea 03 <80> 3c 02 00 0f 85 f7 01 00 00 49 8b 5e 10 48 8d 43 08 48 89 c2 48 All code ======== 0: c1 ea 03 shr $0x3,%edx 3: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) 7: 0f 85 2b 02 00 00 jne 0x238 d: 4d 89 77 28 mov %r14,0x28(%r15) 11: 4d 8d 6e 10 lea 0x10(%r14),%r13 15: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 1c: fc ff df 1f: 4d 8d 67 18 lea 0x18(%r15),%r12 23: 4c 89 ea mov %r13,%rdx 26: 48 c1 ea 03 shr $0x3,%rdx 2a:* 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) <-- trapping instruction 2e: 0f 85 f7 01 00 00 jne 0x22b 34: 49 8b 5e 10 mov 0x10(%r14),%rbx 38: 48 8d 43 08 lea 0x8(%rbx),%rax 3c: 48 89 c2 mov %rax,%rdx 3f: 48 rex.W Code starting with the faulting instruction =========================================== 0: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) 4: 0f 85 f7 01 00 00 jne 0x201 a: 49 8b 5e 10 mov 0x10(%r14),%rbx e: 48 8d 43 08 lea 0x8(%rbx),%rax 12: 48 89 c2 mov %rax,%rdx 15: 48 rex.W The kernel config and materials to reproduce are available at: https://download.01.org/0day-ci/archive/20250930/202509301440.be4b3631-lkp@intel.com -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki-- Masami Hiramatsu (Google) [off-list ref]