Re: [mm] db8d280d38: PANIC:early_exception

[Zhaoyang Huang]

@Vlastimil Could you please have an eye on this series of robot
reports which are caused by stack_depot_init related issues. The
problem arises from a very early access of stack_depot_save/init by
kmemleak within setup_arch which happens even before
stack_depot_early_init and zone related data ready. I would like to
suggest adding a criteria at the entrance check of stack_depot_save
which help the stackdepot API more aggregation and the caller free to
call

[    0.062350][    T0]  ? stack_depot_init.cold+0x5/0xbd
[    0.063072][    T0]  ? set_track_prepare+0x6e/0x80
[    0.063957][    T0]  ?
__raw_callee_save___native_queued_spin_unlock+0x11/0x22
[    0.064952][    T0]  ? write_comp_data+0x2a/0x80
[    0.065623][    T0]  ? strncpy+0x2f/0x60
[    0.066205][    T0]  ? __create_object+0x10c/0x3c0
[    0.066904][    T0]  ? kmemleak_alloc_phys+0x6f/0x80
[    0.067561][    T0]  ? memblock_alloc_range_nid+0x274/0x28f
[    0.068396][    T0]  ? memblock_phys_alloc_range+0xa4/0xb3
[    0.069200][    T0]  ? reserve_real_mode+0x87/0xd7
[    0.069895][    T0]  ? setup_arch+0x6a9/0x995
[    0.070526][    T0]  ? start_kernel+0x7c/0x854
[    0.071195][    T0]  ? load_ucode_bsp+0x1bb/0x1c6
[    0.071875][    T0]  ? secondary_startup_64_no_verify+0xe0/0xeb
[    0.072682][    T0]  </TASK>

On Thu, Oct 13, 2022 at 1:58 PM kernel test robot <oliver.sang@xxxxxxxxx> wrote:
>
>
> Hi zhaoyang.huang,
>
> seems this is the fix based on our report
>     "[mm]  0e949320db: BUG:kernel_NULL_pointer_dereference,address"
> at
>     https://lore.kernel.org/all/202210121406.d4ebc9bc-oliver.sang@xxxxxxxxx/
> but now it seems have new issue. report FYI
>
>
> Greeting,
>
> FYI, we noticed the following commit (built with gcc-11):
>
> commit: db8d280d38efb061ad1a57ce060cbb917a4cf503 ("[RFC PATCHv2] mm: use stack_depot for recording kmemleak's backtrace")
> url: https://github.com/intel-lab-lkp/linux/commits/zhaoyang-huang/mm-use-stack_depot-for-recording-kmemleak-s-backtrace/20221012-160458
> base: https://git.kernel.org/cgit/linux/kernel/git/akpm/mm.git mm-everything
> patch link: https://lore.kernel.org/linux-mm/1665561689-29498-1-git-send-email-zhaoyang.huang@xxxxxxxxxx
> patch subject: [RFC PATCHv2] mm: use stack_depot for recording kmemleak's backtrace
>
> in testcase: boot
>
> on test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 16G
>
> caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace):
>
>
> +-------------------------------+------------+------------+
> |                               | 95f1b43741 | db8d280d38 |
> +-------------------------------+------------+------------+
> | boot_successes                | 20         | 0          |
> | boot_failures                 | 0          | 18         |
> | PANIC:early_exception         | 0          | 18         |
> | RIP:nr_free_zone_pages        | 0          | 18         |
> | BUG:kernel_hang_in_boot_stage | 0          | 18         |
> +-------------------------------+------------+------------+
>
>
> If you fix the issue, kindly add following tag
> | Reported-by: kernel test robot <oliver.sang@xxxxxxxxx>
> | Link: https://lore.kernel.org/r/202210131309.fe5427b-oliver.sang@xxxxxxxxx
>
>
> [    0.029254][    T0] Scan for SMP in [mem 0x00000000-0x000003ff]
> [    0.030178][    T0] Scan for SMP in [mem 0x0009fc00-0x0009ffff]
> [    0.031080][    T0] Scan for SMP in [mem 0x000f0000-0x000fffff]
> [    0.043370][    T0] found SMP MP-table at [mem 0x000f5ba0-0x000f5baf]
> [    0.044301][    T0]   mpc: f5bb0-f5c80
> PANIC: early exception 0x0e IP 10:ffffffff8149c282 error 0 cr2 0x1e08
> [    0.045770][    T0] CPU: 0 PID: 0 Comm: swapper Not tainted 6.0.0-rc3-00711-gdb8d280d38ef #5
> [    0.046970][    T0] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-debian-1.16.0-4 04/01/2014
> [ 0.048356][ T0] RIP: 0010:nr_free_zone_pages (kbuild/src/x86_64-2/include/linux/mmzone.h:1478 kbuild/src/x86_64-2/include/linux/mmzone.h:1504 kbuild/src/x86_64-2/mm/page_alloc.c:5886)
> [ 0.049158][ T0] Code: e9 a3 5c 0b 00 0f 1f 00 e8 9b cd be ff 65 8b 05 14 b8 b8 7e 48 98 41 54 48 8b 04 c5 e0 e4 bc 83 53 89 fb 4c 8d 80 00 1e 00 00 <3b> b8 08 1e 00 00 72 5b 49 8b 10 45 31 e4 48 85 d2 75 05 eb 35 49
> All code
> ========
>    0:   e9 a3 5c 0b 00          jmpq   0xb5ca8
>    5:   0f 1f 00                nopl   (%rax)
>    8:   e8 9b cd be ff          callq  0xffffffffffbecda8
>    d:   65 8b 05 14 b8 b8 7e    mov    %gs:0x7eb8b814(%rip),%eax        # 0x7eb8b828
>   14:   48 98                   cltq
>   16:   41 54                   push   %r12
>   18:   48 8b 04 c5 e0 e4 bc    mov    -0x7c431b20(,%rax,8),%rax
>   1f:   83
>   20:   53                      push   %rbx
>   21:   89 fb                   mov    %edi,%ebx
>   23:   4c 8d 80 00 1e 00 00    lea    0x1e00(%rax),%r8
>   2a:*  3b b8 08 1e 00 00       cmp    0x1e08(%rax),%edi                <-- trapping instruction
>   30:   72 5b                   jb     0x8d
>   32:   49 8b 10                mov    (%r8),%rdx
>   35:   45 31 e4                xor    %r12d,%r12d
>   38:   48 85 d2                test   %rdx,%rdx
>   3b:   75 05                   jne    0x42
>   3d:   eb 35                   jmp    0x74
>   3f:   49                      rex.WB
>
> Code starting with the faulting instruction
> ===========================================
>    0:   3b b8 08 1e 00 00       cmp    0x1e08(%rax),%edi
>    6:   72 5b                   jb     0x63
>    8:   49 8b 10                mov    (%r8),%rdx
>    b:   45 31 e4                xor    %r12d,%r12d
>    e:   48 85 d2                test   %rdx,%rdx
>   11:   75 05                   jne    0x18
>   13:   eb 35                   jmp    0x4a
>   15:   49                      rex.WB
> [    0.051803][    T0] RSP: 0000:ffffffff83603d18 EFLAGS: 00010046 ORIG_RAX: 0000000000000000
> [    0.052881][    T0] RAX: 0000000000000000 RBX: 0000000000000002 RCX: 0001ffff84b317e0
> [    0.053932][    T0] RDX: 0000000000000485 RSI: 0001ffffffffffff RDI: 0000000000000002
> [    0.055007][    T0] RBP: ffffffff84b077d0 R08: 0000000000001e00 R09: 0000000000000000
> [    0.056054][    T0] R10: ffffffff81b16d30 R11: 0001ffff84b317e8 R12: 0000000000000001
> [    0.057088][    T0] R13: ffffffff84b077d8 R14: 0000000000098000 R15: 0000000000007000
> [    0.058160][    T0] FS:  0000000000000000(0000) GS:ffffffff842c9000(0000) knlGS:0000000000000000
> [    0.059440][    T0] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [    0.060381][    T0] CR2: 0000000000001e08 CR3: 00000000043b6000 CR4: 00000000000406a0
> [    0.061516][    T0] Call Trace:
> [    0.061969][    T0]  <TASK>
> [ 0.062350][ T0] ? stack_depot_init.cold (kbuild/src/x86_64-2/lib/stackdepot.c:258)
> [ 0.063072][ T0] ? set_track_prepare (kbuild/src/x86_64-2/mm/slub.c:752)
> [ 0.063957][ T0] ? __raw_callee_save___native_queued_spin_unlock (??:?)
> [ 0.064952][ T0] ? write_comp_data (kbuild/src/x86_64-2/kernel/kcov.c:236)
>
>
> To reproduce:
>
>         # build kernel
>         cd linux
>         cp config-6.0.0-rc3-00711-gdb8d280d38ef .config
>         make HOSTCC=gcc-11 CC=gcc-11 ARCH=x86_64 olddefconfig prepare modules_prepare bzImage modules
>         make HOSTCC=gcc-11 CC=gcc-11 ARCH=x86_64 INSTALL_MOD_PATH=<mod-install-dir> modules_install
>         cd <mod-install-dir>
>         find lib/ | cpio -o -H newc --quiet | gzip > modules.cgz
>
>
>         git clone https://github.com/intel/lkp-tests.git
>         cd lkp-tests
>         bin/lkp qemu -k <bzImage> -m modules.cgz job-script # job-script is attached in this email
>
>         # if come across any failure that blocks the test,
>         # please remove ~/.lkp and /lkp dir to run from a clean state.
>
>
>
> --
> 0-DAY CI Kernel Test Service
> https://01.org/lkp
>
>