[danielhua]

Cool, thanks for the quick fix. It seems the issue is fixed in the latest installer and it starts working, I will try and play with it more. Appreciate it!

-Daniel

[danielhua]

Correct, it was because my ubuntu kernel version is 5.4.0

vagrant@nitest2:/tmp/LinuxKernelDebugHelper-76b64643-3d2f-4153-867c-af871a16d872$ uname -a
Linux nitest2 5.4.0-70-generic #78-Ubuntu SMP Fri Mar 19 13:29:52 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux

After I change the version check to enable the USE_NEW_MODULE_ATTRIBUTE_LAYOUT  check for  5.4.0 and rebuilt the kernel module, it could be loaded successfully (I will need to copy it from the tmp and reboot vm to load it manually). But there is still error when I tried to proceed in vs2017, it seems to skip the build and load LinuxKernelDebugHelper steps and still errors as “Failed to start GDB session, No such host is known“, do you think it is the same issue or a different one?

(gdb begin)
— GDB Session —
Your VisualKernel trial expires in 29 days!
-file-exec-and-symbols “C:\\Program\ Files\ \(x86\)\\Sysprogs\\VisualKernel\\KernelTools\\amd64\\dummy\.elf”
=thread-group-added,id=”i1″
~”GNU gdb (GDB) 8.0.1\n”
~”Copyright (C) 2017 Free Software Foundation, Inc.\n”
~”License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html&gt;\nThis is free software: you are free to change and redistribute it.\nThere is NO WARRANTY, to the extent permitted by law. Type \”show copying\”\nand \”show warranty\” for details.\n”
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html&gt;
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law. Type “show copying”
and “show warranty” for details.
~”This GDB was configured as \”–host=i686-w64-mingw32 –target=x86_64-linux-gnu\”.\nType \”show configuration\” for configuration details.”
This GDB was configured as “–host=i686-w64-mingw32 –target=x86_64-linux-gnu”.
Type “show configuration” for configuration details.
~”\nFor bug reporting instructions, please see:\n”
~”<http://www.gnu.org/software/gdb/bugs/&gt;.\n”
~”Find the GDB manual and other documentation resources online at:\n<http://www.gnu.org/software/gdb/documentation/&gt;.\n”
Find the GDB manual and other documentation resources online at:
<http://www.gnu.org/software/gdb/documentation/&gt;.
~”For help, type \”help\”.\n”
~”Type \”apropos word\” to search for commands related to \”word\”.\n”
^done
add-symbol-file c:/KernelCache/5.4.0-70-generic_0.kernel/vmlinux-5.4.0-70-generic 0xffffffffa8200000 -s .notes 0xffffffffa9000eb4 -s __ex_table 0xffffffffa90010a0 -s .rodata 0xffffffffa9200000 -s .pci_fixup 0xffffffffa967bd80 -s .tracedata 0xffffffffa967eeb0 -s __ksymtab 0xffffffffa967ef28 -s __ksymtab_gpl 0xffffffffa968ef54 -s __kcrctab 0xffffffffa969fa84 -s __kcrctab_gpl 0xffffffffa96a4fe8 -s __ksymtab_strings 0xffffffffa96aa8f8 -s __init_rodata 0xffffffffa96e0580 -s __param 0xffffffffa96e0810 -s __modver 0xffffffffa96e3ee0 -s .data 0xffffffffa9800000 -s __bug_table 0xffffffffa9a58040 -s .vvar 0xffffffffa9a6e000 -s .data..percpu 0x0 -s .init.text 0xffffffffa9a9d000 -s .init.data 0xffffffffa9b2a000 -s .x86_cpu_dev.init 0xffffffffa9cefd78 -s .parainstructions 0xffffffffa9cefda0 -s .altinstructions 0xffffffffa9d10bf0 -s .iommu_table 0xffffffffa9d16f80 -s .apicdrivers 0xffffffffa9d17098 -s .exit.text 0xffffffffa9d170d8 -s .smp_locks 0xffffffffa9d1a000 -s .data_nosave 0xffffffffa9d24000 -s .bss 0xffffffffa9d25000 -s .brk 0xffffffffaa200000 -s .init.scratch 0xffffffffaa400000
&”add-symbol-file c:/KernelCache/5.4.0-70-generic_0.kernel/vmlinux-5.4.0-70-generic 0xffffffffa8200000 -s .notes 0xffffffffa9000eb4 -s __ex_table 0xffffffffa90010a0 -s .rodata 0xffffffffa9200000 -s .pci_fixup 0xffffffffa967bd80 -s .tracedata 0xffffffffa967eeb0 -s __ksymtab 0xffffffffa967ef28 -s __ksymtab_gpl 0xffffffffa968ef54 -s __kcrctab 0xffffffffa969fa84 -s __kcrctab_gpl 0xffffffffa96a4fe8 -s __ksymtab_strings 0xffffffffa96aa8f8 -s __init_rodata 0xffffffffa96e0580 -s __param 0xffffffffa96e0810 -s __modver 0xffffffffa96e3ee0 -s .data 0xffffffffa9800000 -s __bug_table 0xffffffffa9a58040 -s .vvar 0xffffffffa9a6e000 -s .data..percpu 0x0 -s .init.text 0xffffffffa9a9d000 -s .init.data 0xffffffffa9b2a000 -s .x86_cpu_dev.init 0xffffffffa9cefd78 -s .parainstructions 0xffffffffa9cefda0 -s .altinstructions 0xffffffffa9d10bf0 -s .iommu_table 0xffffffffa9d16f80 -s .apicdrivers 0xffffffffa9d17098 -s .exit.text 0xffffffffa9d170d8 -s .smp_locks 0xffffffffa9d1a000 -s .data_nosave 0xffffffffa9d24000 -s .bss 0xffffffffa9d25000 -s .brk 0xffffffffaa200000 -s .init.scratch 0xffffffffaa400000\n”
~”add symbol table from file \”c:/KernelCache/5.4.0-70-generic_0.kernel/vmlinux-5.4.0-70-generic\” at\n”
~”\t.text_addr = 0xffffffffa8200000\n”
~”\t.notes_addr = 0xffffffffa9000eb4\n”
~”\t__ex_table_addr = 0xffffffffa90010a0\n”
~”\t.rodata_addr = 0xffffffffa9200000\n”
~”\t.pci_fixup_addr = 0xffffffffa967bd80\n”
~”\t.tracedata_addr = 0xffffffffa967eeb0\n”
~”\t__ksymtab_addr = 0xffffffffa967ef28\n”
~”\t__ksymtab_gpl_addr = 0xffffffffa968ef54\n”
~”\t__kcrctab_addr = 0xffffffffa969fa84\n”
~”\t__kcrctab_gpl_addr = 0xffffffffa96a4fe8\n”
~”\t__ksymtab_strings_addr = 0xffffffffa96aa8f8\n”
~”\t__init_rodata_addr = 0xffffffffa96e0580\n”
~”\t__param_addr = 0xffffffffa96e0810\n”
~”\t__modver_addr = 0xffffffffa96e3ee0\n”
~”\t.data_addr = 0xffffffffa9800000\n”
~”\t__bug_table_addr = 0xffffffffa9a58040\n”
~”\t.vvar_addr = 0xffffffffa9a6e000\n”
~”\t.data..percpu_addr = 0x0\n”
~”\t.init.text_addr = 0xffffffffa9a9d000\n”
~”\t.init.data_addr = 0xffffffffa9b2a000\n”
~”\t.x86_cpu_dev.init_addr = 0xffffffffa9cefd78\n”
~”\t.parainstructions_addr = 0xffffffffa9cefda0\n”
~”\t.altinstructions_addr = 0xffffffffa9d10bf0\n”
~”\t.iommu_table_addr = 0xffffffffa9d16f80\n”
~”\t.apicdrivers_addr = 0xffffffffa9d17098\n”
~”\t.exit.text_addr = 0xffffffffa9d170d8\n”
~”\t.smp_locks_addr = 0xffffffffa9d1a000\n”
~”\t.data_nosave_addr = 0xffffffffa9d24000\n”
~”\t.bss_addr = 0xffffffffa9d25000\n”
~”\t.brk_addr = 0xffffffffaa200000\n”
~”\t.init.scratch_addr = 0xffffffffaa400000\n”
~”(y or n) [answered Y; input not from terminal]\n”
~”Reading symbols from c:/KernelCache/5.4.0-70-generic_0.kernel/vmlinux-5.4.0-70-generic…”
~”done.\n”
-gdb-version
^done
~”GNU gdb (GDB) 8.0.1\n”
~”Copyright (C) 2017 Free Software Foundation, Inc.\n”
~”License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html&gt;\nThis is free software: you are free to change and redistribute it.\nThere is NO WARRANTY, to the extent permitted by law. Type \”show copying\”\nand \”show warranty\” for details.\n”
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html&gt;
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law. Type “show copying”
and “show warranty” for details.
~”This GDB was configured as \”–host=i686-w64-mingw32 –target=x86_64-linux-gnu\”.\nType \”show configuration\” for configuration details.”
This GDB was configured as “–host=i686-w64-mingw32 –target=x86_64-linux-gnu”.
Type “show configuration” for configuration details.
~”\nFor bug reporting instructions, please see:\n”
~”<http://www.gnu.org/software/gdb/bugs/&gt;.\n”
~”Find the GDB manual and other documentation resources online at:\n<http://www.gnu.org/software/gdb/documentation/&gt;.\n”
Find the GDB manual and other documentation resources online at:
<http://www.gnu.org/software/gdb/documentation/&gt;.
~”For help, type \”help\”.\n”
~”Type \”apropos word\” to search for commands related to \”word\”.\n”
^done
-list-features
^done,features=[“frozen-varobjs”,”pending-breakpoints”,”thread-info”,”data-read-memory-bytes”,”breakpoint-notifications”,”ada-task-info”,”language-option”,”info-gdb-mi-command”,”undefined-command-error-code”,”exec-run-start-option”]
-gdb-set disassembly-flavor intel
^done
-gdb-set print demangle off
^done
info target
&”info target\n”
~”Symbols from \”C:\\Program Files (x86)\\Sysprogs\\VisualKernel\\KernelTools\\amd64\\dummy.elf\”.\n”
^done

— Linux 5.4.0-70-generic —
VisualKernel has hooked printk() and will display its output in this window.
You can disable this in VisualKernel Project Properties.

I am looking forward to testing your new installer with the change and hopefully it fixes the issue and would allow me do some kernel debugging.

Thanks,

Daniel

• This reply was modified 3 years, 7 months ago by danielhua.
• This reply was modified 3 years, 7 months ago by danielhua.

[danielhua]

Dear Support,

Thanks for responding so quickly. I tried to install the updated VisualKernel 3.1R8 from the link, it seems the issue persists. I got the exactly same error in vs2017 saying “Cannot load LinuxKernelDebugHelper.ko” after the module gets built. And dmesg info indicates the same issue:

 

[ 2858.804289] LinuxKernelDebugHelper: module verification failed: signature and/or required key missing – tainting kernel
[ 2858.833211] BUG: kernel NULL pointer dereference, address: 0000000000000100
[ 2858.835544] #PF: supervisor read access in kernel mode
[ 2858.837204] #PF: error_code(0x0000) – not-present page
[ 2858.838917] PGD 0 P4D 0
[ 2858.839812] Oops: 0000 [#1] SMP PTI
[ 2858.841013] CPU: 3 PID: 6499 Comm: insmod Tainted: G OE 5.4.0-70-generic #78-Ubuntu
[ 2858.843890] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[ 2858.846473] RIP: 0010:strlen+0x0/0x20
[ 2858.847711] Code: 48 89 f9 74 09 48 83 c1 01 80 39 00 75 f7 31 d2 44 0f b6 04 16 44 88 04 11 48 83 c2 01 45 84 c0 75 ee c3 0f 1f 80 00 00 00 00 <80> 3f 00 74 10 48 89 f8 48 83 c0 01 80 38 00 75 f7 48 29 f8 c3 31
[ 2858.853843] RSP: 0018:ffff9e5481eb7bb8 EFLAGS: 00010202
[ 2858.855561] RAX: 0000000000000001 RBX: 0000000000000002 RCX: 0000000000000000
[ 2858.857878] RDX: 0000000000000000 RSI: ffff9e5481eb7bc8 RDI: 0000000000000100
[ 2858.859883] RBP: ffff9e5481eb7c08 R08: 0000000000000000 R09: 0000000000800000
[ 2858.861726] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000100
[ 2858.863596] R13: ffff8e5e9ad53660 R14: ffffffffc08ee080 R15: 0000000000000001
[ 2858.865454] FS: 00007fabb6b66540(0000) GS:ffff8e5edbb80000(0000) knlGS:0000000000000000
[ 2858.867747] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 2858.869408] CR2: 0000000000000100 CR3: 000000011548c001 CR4: 00000000000606e0
[ 2858.871957] Call Trace:
[ 2858.872853] ? AppendSequentialModuleInfo+0x98/0x10d [LinuxKernelDebugHelper]
[ 2858.874957] ? 0xffffffffc08ec000
[ 2858.876053] UpdateGlobalModuleList+0x86/0xe0 [LinuxKernelDebugHelper]
[ 2858.878032] ModuleNotificationCallback+0x122/0x140 [LinuxKernelDebugHelper]
[ 2858.880268] notifier_call_chain+0x55/0x80
[ 2858.881530] blocking_notifier_call_chain+0x50/0x70
[ 2858.883012] do_init_module+0x8c/0x260
[ 2858.884193] load_module+0x11a3/0x12a0
[ 2858.885388] __do_sys_finit_module+0xbe/0x120
[ 2858.886819] ? __do_sys_finit_module+0xbe/0x120
[ 2858.888357] __x64_sys_finit_module+0x1a/0x20
[ 2858.889689] do_syscall_64+0x57/0x190
[ 2858.891180] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 2858.892711] RIP: 0033:0x7fabb6cab89d
[ 2858.893880] Code: 00 c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 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 c3 f5 0c 00 f7 d8 64 89 01 48
[ 2858.899005] RSP: 002b:00007ffdf26c0ce8 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
[ 2858.901294] RAX: ffffffffffffffda RBX: 0000556dd27ca7a0 RCX: 00007fabb6cab89d
[ 2858.903330] RDX: 0000000000000000 RSI: 0000556dd27ca2a0 RDI: 0000000000000003
[ 2858.905358] RBP: 0000000000000000 R08: 0000000000000000 R09: 00007ffdf26c0ea8
[ 2858.907352] R10: 0000000000000003 R11: 0000000000000246 R12: 0000556dd27ca2a0
[ 2858.909733] R13: 0000000000000000 R14: 0000556dd27ca370 R15: 0000556dd27ca2a0
[ 2858.912085] Modules linked in: LinuxKernelDebugHelper(OE) vboxsf(O) md4 cmac cifs libarc4 fscache libdes isofs binfmt_misc dm_multipath scsi_dh_rdac scsi_dh_emc scsi_dh_alua input_leds vboxguest(O) serio_raw video sch_fq_codel nfsd auth_rpcgss nfs_acl lockd grace drm sunrpc ip_tables x_tables autofs4 btrfs zstd_compress raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c raid1 raid0 multipath linear crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel mptspi scsi_transport_spi crypto_simd mptscsih cryptd glue_helper psmouse e1000 mptbase
[ 2858.926282] CR2: 0000000000000100
[ 2858.927430] —[ end trace a83e2daecf38b983 ]—
[ 2858.928882] RIP: 0010:strlen+0x0/0x20
[ 2858.930039] Code: 48 89 f9 74 09 48 83 c1 01 80 39 00 75 f7 31 d2 44 0f b6 04 16 44 88 04 11 48 83 c2 01 45 84 c0 75 ee c3 0f 1f 80 00 00 00 00 <80> 3f 00 74 10 48 89 f8 48 83 c0 01 80 38 00 75 f7 48 29 f8 c3 31
[ 2858.959458] RSP: 0018:ffff9e5481eb7bb8 EFLAGS: 00010202
[ 2858.961055] RAX: 0000000000000001 RBX: 0000000000000002 RCX: 0000000000000000
[ 2858.963138] RDX: 0000000000000000 RSI: ffff9e5481eb7bc8 RDI: 0000000000000100
[ 2858.965197] RBP: ffff9e5481eb7c08 R08: 0000000000000000 R09: 0000000000800000
[ 2858.967300] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000100
[ 2858.969330] R13: ffff8e5e9ad53660 R14: ffffffffc08ee080 R15: 0000000000000001
[ 2858.971707] FS: 00007fabb6b66540(0000) GS:ffff8e5edbb80000(0000) knlGS:0000000000000000
[ 2858.974237] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 2858.976003] CR2: 0000000000000100 CR3: 000000011548c001 CR4: 00000000000606e0

I also tried uninstall and then install the latest Visualkernel, nothing changes. Please help check if the new installer contains the fix for this issue.

Thanks,

Daniel

[Author]

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