[jimc:jb-fix] [dynamic_debug] d405145208: Oops:general_protection_fault,probably_for_non-canonical_address#:#[##]SMP_KASAN

kernel test robot <[email protected]> Fri, 26 Jun 2026 14:54:29 +0800
Newsgroups dev.linux.lists.oe-lkp
Message-ID <[email protected]>
hi, Jim Cromie,

we understand this patch is to fix the issue we reported for i386.
https://lore.kernel.org/oe-lkp/[email protected]/

however, we found it caused regression for x86_64. just FYI.


Hello,

kernel test robot noticed "Oops:general_protection_fault,probably_for_non-canonical_address#:#[##]SMP_KASAN" on:

commit: d4051452089e61a8aa3b39330981fc21d40aa60d ("dynamic_debug: Simplify classmap macros by removing redundant aligned(8) attributes")
https://github.com/jimc/linux.git jb-fix

in testcase: boot

config: x86_64-randconfig-004-20260623
compiler: gcc-14
test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 32G

(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 <[email protected]>
| Closes: https://lore.kernel.org/oe-lkp/[email protected]



[    2.487444][    T1] Oops: general protection fault, probably for non-canonical address 0xe007ffe1e0000000: 0000 [#1] SMP KASAN
[    2.487955][    T1] KASAN: maybe wild-memory-access in range [0x00401f0f00000000-0x00401f0f00000007]
[    2.487955][    T1] CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 7.1.0-00050-gd4051452089e #1 PREEMPTLAZY
[    2.487955][    T1] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[    2.487955][    T1] RIP: 0010:strcmp (kbuild/src/lib/string.c:283)
[    2.487955][    T1] Code: 41 55 41 54 53 48 89 fb 48 83 ec 08 eb 08 45 84 e4 74 65 4c 89 ee 48 89 df 48 83 c3 01 48 89 f8 48 89 fa 48 c1 e8 03 83 e2 07 <42> 0f b6 04 30 38 d0 7f 04 84 c0 75 60 48 89 f0 48 89 f2 44 0f b6
All code
========
   0:	41 55                	push   %r13
   2:	41 54                	push   %r12
   4:	53                   	push   %rbx
   5:	48 89 fb             	mov    %rdi,%rbx
   8:	48 83 ec 08          	sub    $0x8,%rsp
   c:	eb 08                	jmp    0x16
   e:	45 84 e4             	test   %r12b,%r12b
  11:	74 65                	je     0x78
  13:	4c 89 ee             	mov    %r13,%rsi
  16:	48 89 df             	mov    %rbx,%rdi
  19:	48 83 c3 01          	add    $0x1,%rbx
  1d:	48 89 f8             	mov    %rdi,%rax
  20:	48 89 fa             	mov    %rdi,%rdx
  23:	48 c1 e8 03          	shr    $0x3,%rax
  27:	83 e2 07             	and    $0x7,%edx
  2a:*	42 0f b6 04 30       	movzbl (%rax,%r14,1),%eax		<-- trapping instruction
  2f:	38 d0                	cmp    %dl,%al
  31:	7f 04                	jg     0x37
  33:	84 c0                	test   %al,%al
  35:	75 60                	jne    0x97
  37:	48 89 f0             	mov    %rsi,%rax
  3a:	48 89 f2             	mov    %rsi,%rdx
  3d:	44                   	rex.R
  3e:	0f                   	.byte 0xf
  3f:	b6                   	.byte 0xb6

Code starting with the faulting instruction
===========================================
   0:	42 0f b6 04 30       	movzbl (%rax,%r14,1),%eax
   5:	38 d0                	cmp    %dl,%al
   7:	7f 04                	jg     0xd
   9:	84 c0                	test   %al,%al
   b:	75 60                	jne    0x6d
   d:	48 89 f0             	mov    %rsi,%rax
  10:	48 89 f2             	mov    %rsi,%rdx
  13:	44                   	rex.R
  14:	0f                   	.byte 0xf
  15:	b6                   	.byte 0xb6
[    2.487955][    T1] RSP: 0000:ffffc9000001fc10 EFLAGS: 00010246
[    2.487955][    T1] RAX: 000803e1e0000000 RBX: 00401f0f00000001 RCX: 000000005555555c
[    2.487955][    T1] RDX: 0000000000000000 RSI: ffffffff88a01760 RDI: 00401f0f00000000
[    2.487955][    T1] RBP: ffffc9000001fc38 R08: 0000000000000000 R09: 0000000000000000
[    2.487955][    T1] R10: ffffc9000001fd30 R11: 0000000000000000 R12: 0000000f8d1165e8
[    2.487955][    T1] R13: ffffc9000001fd30 R14: dffffc0000000000 R15: 0000000000000000
[    2.487955][    T1] FS:  0000000000000000(0000) GS:ffff888790b4a000(0000) knlGS:0000000000000000
[    2.487955][    T1] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    2.487955][    T1] CR2: ffff88883ffff000 CR3: 000000000aee4000 CR4: 00000000000406f0
[    2.487955][    T1] Call Trace:
[    2.487955][    T1]  <TASK>
[    2.487955][    T1]  ddebug_add_module (kbuild/src/lib/dynamic_debug.c:1572 (discriminator 8))
[    2.487955][    T1]  ? __up_write (kbuild/src/include/linux/instrumented.h:112 kbuild/src/include/linux/atomic/atomic-instrumented.h:3390 kbuild/src/kernel/locking/rwsem.c:1415)
[    2.487955][    T1]  ? up_write (kbuild/src/kernel/locking/rwsem.c:1682)
[    2.487955][    T1]  dynamic_debug_init (kbuild/src/lib/dynamic_debug.c:1815)


The kernel config and materials to reproduce are available at:
https://download.01.org/0day-ci/archive/20260626/[email protected]



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