From: kernel test robot <oliver.sang@intel.com>
To: "Jim Cromie" <jim.cromie@gmail.com>,
"Łukasz Bartosik" <ukaszb@chromium.org>
Cc: <oe-lkp@lists.linux.dev>, <lkp@intel.com>, <oliver.sang@intel.com>
Subject: [jimc:dd-rust-parse-2b] [dynamic_debug] f9ffb9cd4c: BUG:kernel_NULL_pointer_dereference,address
Date: Fri, 26 Jun 2026 17:21:17 +0800 [thread overview]
Message-ID: <202606261624.8bb81239-lkp@intel.com> (raw)
hi, Jim Cromie,
we just reported
"[jimc:jb-fix] [dynamic_debug] d405145208: Oops:general_protection_fault,probably_for_non-canonical_address#:#[##]SMP_KASAN"
in
https://lore.kernel.org/all/202606261437.36507000-lkp@intel.com/
two hours ago.
where I assumed the patch is a fix for i386, but maybe caused regression in
our x86_64 boot tests.
however, later, I found our bot happened to test i386 boot in another branch
and capture this change cause regression on i386 boot tests - parent can boot
successfully, but this change will break the i386 boot, too.
so report again FYI.
Hello,
kernel test robot noticed "BUG:kernel_NULL_pointer_dereference,address" on:
commit: f9ffb9cd4ce0b19f39fd6dd5361e9d067c9be714 ("dynamic_debug: Simplify classmap macros by removing redundant aligned(8) attributes")
https://github.com/jimc/linux.git dd-rust-parse-2b
in testcase: boot
config: i386-randconfig-003-20260623
compiler: gcc-14
test machine: qemu-system-i386 -enable-kvm -cpu SandyBridge -smp 2 -m 4G
(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 <oliver.sang@intel.com>
| Closes: https://lore.kernel.org/oe-lkp/202606261624.8bb81239-lkp@intel.com
[ 0.756103][ T1] BUG: kernel NULL pointer dereference, address: 00000000
[ 0.758285][ T1] #PF: supervisor read access in kernel mode
[ 0.759534][ T1] #PF: error_code(0x0000) - not-present page
[ 0.759534][ T1] *pde = 00000000
[ 0.759534][ T1] Oops: Oops: 0000 [#1] SMP
[ 0.759534][ T1] CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Tainted: G T 7.1.0-00050-gf9ffb9cd4ce0 #1 PREEMPT(lazy)
[ 0.759534][ T1] Tainted: [T]=RANDSTRUCT
[ 0.759534][ T1] EIP: strcmp (x86/lib/string_32.c:94)
[ 0.759534][ T1] Code: 49 78 06 ac aa 84 c0 75 f7 31 c0 aa 83 c4 04 89 d8 5b 5e 5f 5d e9 b7 aa 01 00 8d b4 26 00 00 00 00 55 89 e5 57 89 d7 56 89 c6 <ac> ae 75 08 84 c0 75 f8 31 c0 eb 04 19 c0 0c 01 5e 5f 5d e9 8f aa
All code
========
0: 49 78 06 rex.WB js 0x9
3: ac lods %ds:(%rsi),%al
4: aa stos %al,%es:(%rdi)
5: 84 c0 test %al,%al
7: 75 f7 jne 0x0
9: 31 c0 xor %eax,%eax
b: aa stos %al,%es:(%rdi)
c: 83 c4 04 add $0x4,%esp
f: 89 d8 mov %ebx,%eax
11: 5b pop %rbx
12: 5e pop %rsi
13: 5f pop %rdi
14: 5d pop %rbp
15: e9 b7 aa 01 00 jmp 0x1aad1
1a: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi
21: 55 push %rbp
22: 89 e5 mov %esp,%ebp
24: 57 push %rdi
25: 89 d7 mov %edx,%edi
27: 56 push %rsi
28: 89 c6 mov %eax,%esi
2a:* ac lods %ds:(%rsi),%al <-- trapping instruction
2b: ae scas %es:(%rdi),%al
2c: 75 08 jne 0x36
2e: 84 c0 test %al,%al
30: 75 f8 jne 0x2a
32: 31 c0 xor %eax,%eax
34: eb 04 jmp 0x3a
36: 19 c0 sbb %eax,%eax
38: 0c 01 or $0x1,%al
3a: 5e pop %rsi
3b: 5f pop %rdi
3c: 5d pop %rbp
3d: e9 .byte 0xe9
3e: 8f .byte 0x8f
3f: aa stos %al,%es:(%rdi)
Code starting with the faulting instruction
===========================================
0: ac lods %ds:(%rsi),%al
1: ae scas %es:(%rdi),%al
2: 75 08 jne 0xc
4: 84 c0 test %al,%al
6: 75 f8 jne 0x0
8: 31 c0 xor %eax,%eax
a: eb 04 jmp 0x10
c: 19 c0 sbb %eax,%eax
e: 0c 01 or $0x1,%al
10: 5e pop %rsi
11: 5f pop %rdi
12: 5d pop %rbp
13: e9 .byte 0xe9
14: 8f .byte 0x8f
15: aa stos %al,%es:(%rdi)
[ 0.759534][ T1] EAX: 00000000 EBX: 00000000 ECX: 85c8fd00 EDX: 83d2281a
[ 0.759534][ T1] ESI: 00000000 EDI: 83d2281a EBP: 85cc9e6c ESP: 85cc9e64
[ 0.759534][ T1] DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 EFLAGS: 00010246
[ 0.759534][ T1] CR0: 80050033 CR2: 00000000 CR3: 0488f000 CR4: 00040690
[ 0.759534][ T1] Call Trace:
[ 0.759534][ T1] ddebug_add_module (dynamic_debug.c:1572 (discriminator 8))
[ 0.759534][ T1] ? __lock_release+0x115/0x300
[ 0.759534][ T1] ? blocking_notifier_chain_register (notifier.c:265 notifier.c:282)
[ 0.759534][ T1] ? up_write (locking/rwsem.c:1682)
[ 0.759534][ T1] ? blocking_notifier_chain_register (notifier.c:265 notifier.c:282)
[ 0.759534][ T1] ? dynamic_debug_init_control (dynamic_debug.c:1768)
[ 0.759534][ T1] dynamic_debug_init (dynamic_debug.c:1815)
[ 0.759534][ T1] ? dynamic_debug_init_control (dynamic_debug.c:1768)
[ 0.759534][ T1] do_one_initcall (main.c:1392)
[ 0.759534][ T1] ? __register_sysctl_table (linux/spinlock.h:390 proc/proc_sysctl.c:1403)
[ 0.759534][ T1] kernel_init_freeable (main.c:1499 (discriminator 1) main.c:1692 (discriminator 1))
[ 0.759534][ T1] ? rest_init (main.c:762)
[ 0.759534][ T1] kernel_init (main.c:1593)
[ 0.759534][ T1] ret_from_fork (x86/kernel/process.c:158)
[ 0.759534][ T1] ? rest_init (main.c:762)
[ 0.759534][ T1] ret_from_fork_asm (x86/entry/entry_32.S:736)
[ 0.759534][ T1] entry_INT80_32 (x86/entry/entry_32.S:940)
[ 0.759534][ T1] Modules linked in:
[ 0.759534][ T1] CR2: 0000000000000000
[ 0.759534][ T1] ---[ end trace 0000000000000000 ]---
[ 0.759534][ T1] EIP: strcmp (x86/lib/string_32.c:94)
[ 0.759534][ T1] Code: 49 78 06 ac aa 84 c0 75 f7 31 c0 aa 83 c4 04 89 d8 5b 5e 5f 5d e9 b7 aa 01 00 8d b4 26 00 00 00 00 55 89 e5 57 89 d7 56 89 c6 <ac> ae 75 08 84 c0 75 f8 31 c0 eb 04 19 c0 0c 01 5e 5f 5d e9 8f aa
All code
========
0: 49 78 06 rex.WB js 0x9
3: ac lods %ds:(%rsi),%al
4: aa stos %al,%es:(%rdi)
5: 84 c0 test %al,%al
7: 75 f7 jne 0x0
9: 31 c0 xor %eax,%eax
b: aa stos %al,%es:(%rdi)
c: 83 c4 04 add $0x4,%esp
f: 89 d8 mov %ebx,%eax
11: 5b pop %rbx
12: 5e pop %rsi
13: 5f pop %rdi
14: 5d pop %rbp
15: e9 b7 aa 01 00 jmp 0x1aad1
1a: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi
21: 55 push %rbp
22: 89 e5 mov %esp,%ebp
24: 57 push %rdi
25: 89 d7 mov %edx,%edi
27: 56 push %rsi
28: 89 c6 mov %eax,%esi
2a:* ac lods %ds:(%rsi),%al <-- trapping instruction
2b: ae scas %es:(%rdi),%al
2c: 75 08 jne 0x36
2e: 84 c0 test %al,%al
30: 75 f8 jne 0x2a
32: 31 c0 xor %eax,%eax
34: eb 04 jmp 0x3a
36: 19 c0 sbb %eax,%eax
38: 0c 01 or $0x1,%al
3a: 5e pop %rsi
3b: 5f pop %rdi
3c: 5d pop %rbp
3d: e9 .byte 0xe9
3e: 8f .byte 0x8f
3f: aa stos %al,%es:(%rdi)
Code starting with the faulting instruction
===========================================
0: ac lods %ds:(%rsi),%al
1: ae scas %es:(%rdi),%al
2: 75 08 jne 0xc
4: 84 c0 test %al,%al
6: 75 f8 jne 0x0
8: 31 c0 xor %eax,%eax
a: eb 04 jmp 0x10
c: 19 c0 sbb %eax,%eax
e: 0c 01 or $0x1,%al
10: 5e pop %rsi
11: 5f pop %rdi
12: 5d pop %rbp
13: e9 .byte 0xe9
14: 8f .byte 0x8f
15: aa stos %al,%es:(%rdi)
The kernel config and materials to reproduce are available at:
https://download.01.org/0day-ci/archive/20260626/202606261624.8bb81239-lkp@intel.com
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
reply other threads:[~2026-06-26 9:21 UTC|newest]
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