Re: [RFC PATCH] modules: extend {kstrdup,kfree}_const() to handle per-module .rodata
From: kernel test robot
Date: Tue Mar 31 2026 - 09:41:17 EST
Hello,
kernel test robot noticed "kernel_BUG_at_arch/x86/mm/physaddr.c" on:
commit: 0803ad97505a632fc3d0cddd6659617deb0ff34b ("[RFC PATCH] modules: extend {kstrdup,kfree}_const() to handle per-module .rodata")
url: https://github.com/intel-lab-lkp/linux/commits/Dmitry-Antipov/modules-extend-kstrdup-kfree-_const-to-handle-per-module-rodata/20260329-123400
base: https://git.kernel.org/cgit/linux/kernel/git/akpm/mm.git mm-everything
patch link: https://lore.kernel.org/all/20260327132247.861984-1-dmantipov@xxxxxxxxx/
patch subject: [RFC PATCH] modules: extend {kstrdup,kfree}_const() to handle per-module .rodata
in testcase: boot
config: i386-randconfig-002-20260331
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@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-lkp/202603312130.f9ed8d89-lkp@xxxxxxxxx
[ 17.209008][ C0] ------------[ cut here ]------------
[ 17.209572][ C0] kernel BUG at arch/x86/mm/physaddr.c:66!
[ 17.210058][ C0] Oops: invalid opcode: 0000 [#1]
[ 17.210470][ C0] CPU: 0 UID: 0 PID: 13 Comm: ksoftirqd/0 Not tainted 7.0.0-rc5-00667-g0803ad97505a #1 PREEMPT(full) 4fef6f10f7892f9689059524fd4d050b8163a9be
[ 17.211614][ C0] EIP: __phys_addr (arch/x86/mm/physaddr.c:66 (discriminator 3))
[ 17.211995][ C0] Code: e5 56 53 85 c0 78 09 0f 0b b8 ec a1 e6 81 eb 21 80 3d f8 e9 4d 82 00 89 c3 8d b0 00 00 00 80 74 15 e8 cf c5 19 00 84 c0 74 0c <0f> 0b b8 e0 a1 e6 81 e8 77 3e fb ff a1 30 14 d3 82 85 c0 74 2a 89
All code
========
0: e5 56 in $0x56,%eax
2: 53 push %rbx
3: 85 c0 test %eax,%eax
5: 78 09 js 0x10
7: 0f 0b ud2
9: b8 ec a1 e6 81 mov $0x81e6a1ec,%eax
e: eb 21 jmp 0x31
10: 80 3d f8 e9 4d 82 00 cmpb $0x0,-0x7db21608(%rip) # 0xffffffff824dea0f
17: 89 c3 mov %eax,%ebx
19: 8d b0 00 00 00 80 lea -0x80000000(%rax),%esi
1f: 74 15 je 0x36
21: e8 cf c5 19 00 call 0x19c5f5
26: 84 c0 test %al,%al
28: 74 0c je 0x36
2a:* 0f 0b ud2 <-- trapping instruction
2c: b8 e0 a1 e6 81 mov $0x81e6a1e0,%eax
31: e8 77 3e fb ff call 0xfffffffffffb3ead
36: a1 30 14 d3 82 85 c0 movabs 0x2a74c08582d31430,%eax
3d: 74 2a
3f: 89 .byte 0x89
Code starting with the faulting instruction
===========================================
0: 0f 0b ud2
2: b8 e0 a1 e6 81 mov $0x81e6a1e0,%eax
7: e8 77 3e fb ff call 0xfffffffffffb3e83
c: a1 30 14 d3 82 85 c0 movabs 0x2a74c08582d31430,%eax
13: 74 2a
15: 89 .byte 0x89
[ 17.214426][ C0] EAX: f7e9f401 EBX: f7e9f4ac ECX: fffff000 EDX: ff5fe000
[ 17.215476][ C0] ESI: 77e9f4ac EDI: 00000000 EBP: 80b0be68 ESP: 80b0be60
[ 17.216539][ C0] DS: 007b ES: 007b FS: 0000 GS: 0000 SS: 0068 EFLAGS: 00010202
[ 17.217741][ C0] CR0: 80050033 CR2: 7fbf9dd8 CR3: 032cd000 CR4: 000406b0
[ 17.218849][ C0] Call Trace:
[ 17.219371][ C0] kfree (mm/slub.c:6474 (discriminator 1))
[ 17.220011][ C0] ? rcu_read_unlock (include/linux/rcupdate.h:884)
[ 17.220786][ C0] kfree_const (mm/util.c:49)
[ 17.221549][ C0] kernfs_free_rcu (fs/kernfs/dir.c:550)
[ 17.222201][ C0] ? lock_is_held (arch/x86/events/intel/core.c:4034)
[ 17.222920][ C0] rcu_do_batch+0x329/0x6a8
[ 17.223812][ C0] rcu_core (kernel/rcu/tree.c:2871)
[ 17.224493][ C0] rcu_core_si (kernel/rcu/tree.c:2887)
[ 17.225255][ C0] handle_softirqs (arch/x86/include/asm/atomic.h:23 include/linux/atomic/atomic-arch-fallback.h:457 include/linux/jump_label.h:262 include/trace/events/irq.h:142 kernel/softirq.c:623)
[ 17.226002][ C0] run_ksoftirqd (kernel/softirq.c:479 kernel/softirq.c:1064 kernel/softirq.c:1055)
[ 17.226737][ C0] smpboot_thread_fn (kernel/smpboot.c:160)
[ 17.227510][ C0] ? sort_range (kernel/smpboot.c:103)
[ 17.228198][ C0] kthread (kernel/kthread.c:438)
[ 17.228839][ C0] ? sort_range (kernel/smpboot.c:103)
[ 17.229601][ C0] ? kthread_affine_node (kernel/kthread.c:381)
[ 17.230400][ C0] ret_from_fork (arch/x86/kernel/process.c:164)
[ 17.231112][ C0] ? kthread_affine_node (kernel/kthread.c:381)
[ 17.231971][ C0] ret_from_fork_asm (arch/x86/entry/entry_32.S:737)
[ 17.232755][ C0] entry_INT80_32 (arch/x86/entry/entry_32.S:942)
[ 17.233621][ C0] Modules linked in: usbtest(+) serio_raw evdev parport_pc parport qemu_fw_cfg button
[ 17.235190][ C0] ---[ end trace 0000000000000000 ]---
[ 17.236068][ C0] EIP: __phys_addr (arch/x86/mm/physaddr.c:66 (discriminator 3))
[ 17.236831][ C0] Code: e5 56 53 85 c0 78 09 0f 0b b8 ec a1 e6 81 eb 21 80 3d f8 e9 4d 82 00 89 c3 8d b0 00 00 00 80 74 15 e8 cf c5 19 00 84 c0 74 0c <0f> 0b b8 e0 a1 e6 81 e8 77 3e fb ff a1 30 14 d3 82 85 c0 74 2a 89
All code
========
0: e5 56 in $0x56,%eax
2: 53 push %rbx
3: 85 c0 test %eax,%eax
5: 78 09 js 0x10
7: 0f 0b ud2
9: b8 ec a1 e6 81 mov $0x81e6a1ec,%eax
e: eb 21 jmp 0x31
10: 80 3d f8 e9 4d 82 00 cmpb $0x0,-0x7db21608(%rip) # 0xffffffff824dea0f
17: 89 c3 mov %eax,%ebx
19: 8d b0 00 00 00 80 lea -0x80000000(%rax),%esi
1f: 74 15 je 0x36
21: e8 cf c5 19 00 call 0x19c5f5
26: 84 c0 test %al,%al
28: 74 0c je 0x36
2a:* 0f 0b ud2 <-- trapping instruction
2c: b8 e0 a1 e6 81 mov $0x81e6a1e0,%eax
31: e8 77 3e fb ff call 0xfffffffffffb3ead
36: a1 30 14 d3 82 85 c0 movabs 0x2a74c08582d31430,%eax
3d: 74 2a
3f: 89 .byte 0x89
Code starting with the faulting instruction
===========================================
0: 0f 0b ud2
2: b8 e0 a1 e6 81 mov $0x81e6a1e0,%eax
7: e8 77 3e fb ff call 0xfffffffffffb3e83
c: a1 30 14 d3 82 85 c0 movabs 0x2a74c08582d31430,%eax
13: 74 2a
15: 89 .byte 0x89
The kernel config and materials to reproduce are available at:
https://download.01.org/0day-ci/archive/20260331/202603312130.f9ed8d89-lkp@xxxxxxxxx
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki