On 1/7/20 1:57 PM, Anshuman Khandual wrote: > On 12/26/2019 02:19 PM, kernel test robot wrote: >> 46cf053efe Linux 5.5-rc3 >> 87c4696d57 mm/debug: Add tests validating architecture page table helpers >> +------------------------------------------+----------+------------+ >> | | v5.5-rc3 | 87c4696d57 | >> +------------------------------------------+----------+------------+ >> | boot_successes | 32 | 0 | >> | boot_failures | 0 | 11 | >> | kernel_BUG_at_include/linux/mm.h | 0 | 11 | >> | invalid_opcode:#[##] | 0 | 11 | >> | EIP:pgtable_pmd_page_dtor | 0 | 11 | >> | Kernel_panic-not_syncing:Fatal_exception | 0 | 11 | >> +------------------------------------------+----------+------------+ >> >> If you fix the issue, kindly add following tag >> Reported-by: kernel test robot >> >> [ 1.390624] smp: Brought up 1 node, 2 CPUs >> [ 1.390624] smpboot: Max logical packages: 2 >> [ 1.390624] smpboot: Total of 2 processors activated (8783.48 BogoMIPS) >> [ 1.391537] debug_vm_pgtable: debug_vm_pgtable: Validating architecture page table helpers >> [ 1.392382] page:f29b85c0 refcount:0 mapcount:0 mapping:00000000 index:0x0 >> [ 1.393415] raw: 02800000 f29b8624 f29b8584 00000000 00000000 edc22280 ffffffff 00000000 >> [ 1.394178] page dumped because: VM_BUG_ON_PAGE(page->pmd_huge_pte) >> [ 1.394820] ------------[ cut here ]------------ >> [ 1.395296] kernel BUG at include/linux/mm.h:2007! >> [ 1.395942] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC PTI >> [ 1.396463] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.5.0-rc3-00001-g87c4696d57b5e #1 >> [ 1.396722] EIP: pgtable_pmd_page_dtor+0x1a/0x23 >> [ 1.396722] Code: d4 8a 27 c2 e8 16 81 04 00 b2 01 5b 88 d0 5d c3 55 89 e5 52 89 45 fc 8b 45 fc 83 78 08 00 74 0c ba e1 e2 e0 c1 e8 14 99 13 00 <0f> 0b e8 92 eb 13 00 c9 c3 55 89 e5 52 89 45 fc 8b 45 fc 90 8d 74 >> [ 1.396722] EAX: c1e0e2e1 EBX: 2dc2e000 ECX: 00000000 EDX: c1e0e2e1 >> [ 1.396722] ESI: edc2b000 EDI: edc4e010 EBP: ee287f14 ESP: ee287f10 >> [ 1.396722] DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 EFLAGS: 00010246 >> [ 1.396722] CR0: 80050033 CR2: ffffffff CR3: 0226a000 CR4: 001406b0 >> [ 1.396722] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000 >> [ 1.396722] DR6: fffe0ff0 DR7: 00000400 >> [ 1.396722] Call Trace: >> [ 1.396722] mop_up_one_pmd+0x48/0x62 >> [ 1.396722] pgd_free+0x35/0xe0 >> [ 1.396722] __mmdrop+0x42/0x96 >> [ 1.396722] debug_vm_pgtable+0x460/0x47c >> [ 1.396722] kernel_init_freeable+0x84/0x172 >> [ 1.396722] ? rest_init+0xe9/0xe9 >> [ 1.396722] kernel_init+0xd/0xe9 >> [ 1.396722] ret_from_fork+0x1e/0x28 >> [ 1.396722] Modules linked in: >> [ 1.396742] ---[ end trace 9c6f11143a94c590 ]--- >> [ 1.397197] EIP: pgtable_pmd_page_dtor+0x1a/0x23 > Hello, > > Wondering if some one could help me with steps to reproduce this crash ? > Could not reproduce the problem with the patch applied on Linux 5.5-rc3 > when built with the config file provided here on a standard KVM guest. > > - Anshuman Hi Anshuman, You can compile the kernel with config-5.5.0-rc3-00001-g87c4696d57b5e, and run the reproduce script. Both files are in the original report mail. # ./reproduce-yocto-vm-yocto-f91855057302-20191226051639-i386-randconfig-a001-20191225-5.5.0-rc3-00001-g87c4696d57b5e-1 ~/linux/arch/x86/boot/bzImage 2>&1 | tail -20 [    1.471128] Call Trace: [    1.471128]  mop_up_one_pmd+0x48/0x62 [    1.471128]  pgd_free+0x33/0xcc [    1.471128]  __mmdrop+0x42/0x96 [    1.471128]  debug_vm_pgtable+0x45d/0x465 [    1.471128]  kernel_init_freeable+0x83/0x16b [    1.471128]  ? rest_init+0xe0/0xe0 [    1.471128]  kernel_init+0xd/0xe9 [    1.471128]  ret_from_fork+0x1e/0x28 [    1.471128] Modules linked in: [    1.471134] ---[ end trace b241750e0a95311e ]--- [    1.471570] EIP: pgtable_pmd_page_dtor+0x1a/0x23 [    1.472006] Code: ba 9b 0b df c1 e8 eb 71 04 00 5b 89 f0 5e 5d c3 55 89 e5 52 89 45 fc 8b 45 fc 83 78 08 00 74 0c ba b6 0b df c1 e8 d6 51 13 00 <0f> 0b e8 c6 a3 13 00 c9 c3 55 89 e5 52 89 45 fc 8b 45 fc 90 8d 74 [    1.473746] EAX: c1df0bb6 EBX: 2e42d000 ECX: 00000000 EDX: c1df0bb6 [    1.474340] ESI: ee42b000 EDI: ee44e008 EBP: eea87f20 ESP: eea87f1c [    1.474465] DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 EFLAGS: 00010246 [    1.475112] CR0: 80050033 CR2: ffffffff CR3: 02242000 CR4: 001406b0 [    1.475712] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000 [    1.476299] DR6: fffe0ff0 DR7: 00000400 [    1.476661] Kernel panic - not syncing: Fatal exception Best Regards, Rong Chen