ci2 starts bisection 2024-03-06 20:46:19.983209239 +0000 UTC m=+110721.060996760 bisecting fixing commit since 05ef4ccb57746f921003b9340fc2f0532c177f41 building syzkaller on 3222d10cbe77bbedb5a7c455e5bcb6b7081a63b7 ensuring issue is reproducible on original commit 05ef4ccb57746f921003b9340fc2f0532c177f41 testing commit 05ef4ccb57746f921003b9340fc2f0532c177f41 gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 9b075975b03900df1d001dd093d57d72789b52b24354730065ae59222e868117 all runs: crashed: KASAN: use-after-free Read in jbd2_journal_get_write_access representative crash: KASAN: use-after-free Read in jbd2_journal_get_write_access, types: [KASAN] check whether we can drop unnecessary instrumentation disabling configs for [LOCKDEP ATOMIC_SLEEP HANG LEAK UBSAN BUG], they are not needed testing commit 05ef4ccb57746f921003b9340fc2f0532c177f41 gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 9e64ca9b2b6ccde1c08980db68f5a06c6ebf28df911566e1729f0b454d6ad922 run #0: crashed: KASAN: use-after-free Read in jbd2_journal_get_write_access run #1: crashed: KASAN: use-after-free Read in jbd2_journal_get_write_access run #2: crashed: KASAN: use-after-free Read in jbd2_journal_get_write_access run #3: crashed: KASAN: use-after-free Read in jbd2_journal_get_write_access run #4: crashed: KASAN: use-after-free Read in jbd2_journal_get_write_access run #5: crashed: KASAN: use-after-free Read in jbd2_journal_get_write_access run #6: crashed: KASAN: use-after-free Read in jbd2_journal_get_write_access run #7: crashed: KASAN: use-after-free Read in jbd2_journal_get_write_access run #8: crashed: KASAN: use-after-free Read in jbd2_journal_get_write_access run #9: OK representative crash: KASAN: use-after-free Read in jbd2_journal_get_write_access, types: [KASAN] the bug reproduces without the instrumentation disabling configs for [HANG LEAK UBSAN BUG LOCKDEP ATOMIC_SLEEP], they are not needed kconfig minimization: base=4920 full=6161 leaves diff=241 split chunks (needed=false): <241> split chunk #0 of len 241 into 5 parts testing without sub-chunk 1/5 disabling configs for [LOCKDEP ATOMIC_SLEEP HANG LEAK UBSAN BUG], they are not needed testing commit 05ef4ccb57746f921003b9340fc2f0532c177f41 gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 9de3ed25dda6603c5fb8d4c41c70c416db581477bae1cd9336cb20f0993dcc30 all runs: crashed: KASAN: use-after-free Read in jbd2_journal_get_write_access representative crash: KASAN: use-after-free Read in jbd2_journal_get_write_access, types: [KASAN] the chunk can be dropped testing without sub-chunk 2/5 disabling configs for [ATOMIC_SLEEP HANG LEAK UBSAN BUG LOCKDEP], they are not needed testing commit 05ef4ccb57746f921003b9340fc2f0532c177f41 gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 014870d197b9975739f55ca4f375192d26d40f6f34379c2061f3093086b6862d run #0: crashed: KASAN: use-after-free Read in jbd2_journal_get_write_access run #1: crashed: KASAN: use-after-free Read in jbd2_journal_get_write_access run #2: crashed: KASAN: use-after-free Read in jbd2_journal_get_write_access run #3: crashed: KASAN: use-after-free Read in jbd2_journal_get_write_access run #4: crashed: KASAN: use-after-free Read in jbd2_journal_get_write_access run #5: crashed: KASAN: use-after-free Read in jbd2_journal_get_write_access run #6: crashed: KASAN: use-after-free Read in jbd2_journal_get_write_access run #7: crashed: KASAN: use-after-free Read in jbd2_journal_get_write_access run #8: crashed: KASAN: use-after-free Read in jbd2_journal_get_write_access run #9: OK representative crash: KASAN: use-after-free Read in jbd2_journal_get_write_access, types: [KASAN] the chunk can be dropped testing without sub-chunk 3/5 disabling configs for [HANG LEAK UBSAN BUG LOCKDEP ATOMIC_SLEEP], they are not needed testing commit 05ef4ccb57746f921003b9340fc2f0532c177f41 gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 30b89197e66972efcac6e0352ea032bc7f8a261e0a608ae8ab3c869edfca311d all runs: crashed: KASAN: use-after-free Read in jbd2_journal_get_write_access representative crash: KASAN: use-after-free Read in jbd2_journal_get_write_access, types: [KASAN] the chunk can be dropped testing without sub-chunk 4/5 disabling configs for [HANG LEAK UBSAN BUG LOCKDEP ATOMIC_SLEEP], they are not needed testing commit 05ef4ccb57746f921003b9340fc2f0532c177f41 gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: c8aca2bf866a29c6471961f9210fcf0a3d0adef1ab882fe8f4df1f572f125635 all runs: crashed: KASAN: use-after-free Read in jbd2_journal_get_write_access representative crash: KASAN: use-after-free Read in jbd2_journal_get_write_access, types: [KASAN] the chunk can be dropped testing without sub-chunk 5/5 disabling configs for [HANG LEAK UBSAN BUG LOCKDEP ATOMIC_SLEEP], they are not needed testing commit 05ef4ccb57746f921003b9340fc2f0532c177f41 gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.40 failed building 05ef4ccb57746f921003b9340fc2f0532c177f41: net/socket.c:1189: undefined reference to `wext_handle_ioctl' net/socket.c:3383: undefined reference to `compat_wext_handle_ioctl' net/core/net-procfs.c:343: undefined reference to `wext_proc_exit' net/core/net-procfs.c:327: undefined reference to `wext_proc_init' minimized to 45 configs; suspects: [HID_ZEROPLUS USB_NET_MCS7830 USB_NET_NET1080 USB_NET_PLUSB USB_NET_RNDIS_HOST USB_NET_SMSC75XX USB_NET_SMSC95XX USB_NET_SR9700 USB_NET_SR9800 USB_NET_ZAURUS USB_OHCI_HCD USB_OHCI_HCD_PCI USB_OHCI_HCD_PLATFORM USB_OTG USB_OTG_FSM USB_PRINTER USB_SERIAL USB_SERIAL_FTDI_SIO USB_SERIAL_GENERIC USB_SERIAL_PL2303 USB_STORAGE_ALAUDA USB_STORAGE_CYPRESS_ATACB USB_STORAGE_DATAFAB USB_STORAGE_FREECOM USB_STORAGE_ISD200 USB_STORAGE_JUMPSHOT USB_STORAGE_KARMA USB_STORAGE_ONETOUCH USB_STORAGE_SDDR09 USB_STORAGE_SDDR55 USB_STORAGE_USBAT USB_TRANCEVIBRATOR USB_U_AUDIO USB_U_ETHER USB_U_SERIAL USB_WDM WLAN WLAN_VENDOR_ATH WLAN_VENDOR_ATMEL WLAN_VENDOR_BROADCOM WLAN_VENDOR_INTERSIL WLAN_VENDOR_MARVELL WLAN_VENDOR_MEDIATEK WLAN_VENDOR_MICROCHIP WLAN_VENDOR_RALINK WLAN_VENDOR_REALTEK WLAN_VENDOR_RSI WLAN_VENDOR_ZYDAS X86_X32 ZEROPLUS_FF] disabling configs for [ATOMIC_SLEEP HANG LEAK UBSAN BUG LOCKDEP], they are not needed testing current HEAD 993bed180178156a70afdafe8aaf23a117107352 testing commit 993bed180178156a70afdafe8aaf23a117107352 gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: f935408b1665e9ef7ca3f42cfcf2b414a9d18dbec8a4a94c57df2af62c8921b8 all runs: crashed: KASAN: use-after-free Read in jbd2_journal_get_write_access representative crash: KASAN: use-after-free Read in jbd2_journal_get_write_access, types: [KASAN] crash still not fixed/happens on the oldest tested release revisions tested: 7, total time: 1h21m5.600197908s (build: 16m1.12807624s, test: 1h3m16.298621006s) crash still not fixed or there were kernel test errors commit msg: Merge "Merge branch 'android13-5.15' into branch 'android13-5.15-lts'" into android13-5.15-lts crash: KASAN: use-after-free Read in jbd2_journal_get_write_access ================================================================== BUG: KASAN: use-after-free in is_handle_aborted include/linux/jbd2.h:1694 [inline] BUG: KASAN: use-after-free in jbd2_journal_get_write_access+0x10f/0x140 fs/jbd2/transaction.c:1241 Read of size 1 at addr ffff88811fab3b24 by task syz-executor.2/529 CPU: 1 PID: 529 Comm: syz-executor.2 Not tainted 5.15.148-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x38/0x49 lib/dump_stack.c:106 print_address_description.constprop.0+0x24/0x160 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:427 [inline] kasan_report.cold+0x82/0xdb mm/kasan/report.c:444 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report_generic.c:306 is_handle_aborted include/linux/jbd2.h:1694 [inline] jbd2_journal_get_write_access+0x10f/0x140 fs/jbd2/transaction.c:1241 __ext4_journal_get_write_access+0x17c/0x3c0 fs/ext4/ext4_jbd2.c:235 ext4_reserve_inode_write+0x157/0x220 fs/ext4/inode.c:5813 __ext4_mark_inode_dirty+0x10d/0x660 fs/ext4/inode.c:5987 ext4_symlink+0x82f/0xd40 fs/ext4/namei.c:3463 vfs_symlink fs/namei.c:4435 [inline] vfs_symlink+0xe9/0x2b0 fs/namei.c:4420 do_symlinkat+0x134/0x2a0 fs/namei.c:4464 __do_sys_symlink fs/namei.c:4486 [inline] __se_sys_symlink fs/namei.c:4484 [inline] __x64_sys_symlink+0x75/0x90 fs/namei.c:4484 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7fc7f791fba9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fc7f74a20c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000058 RAX: ffffffffffffffda RBX: 00007fc7f7a3ef80 RCX: 00007fc7f791fba9 RDX: 0000000000000000 RSI: 0000000020000180 RDI: 0000000020000140 RBP: 00007fc7f74a2120 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002 R13: 000000000000000b R14: 00007fc7f7a3ef80 R15: 00007ffd266bdd98 Allocated by task 529: kasan_save_stack+0x26/0x50 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:433 [inline] __kasan_slab_alloc+0x94/0xc0 mm/kasan/common.c:466 kasan_slab_alloc include/linux/kasan.h:217 [inline] slab_post_alloc_hook mm/slab.h:550 [inline] slab_alloc_node mm/slub.c:3240 [inline] slab_alloc mm/slub.c:3248 [inline] kmem_cache_alloc+0x197/0x480 mm/slub.c:3253 kmem_cache_zalloc include/linux/slab.h:723 [inline] jbd2_alloc_handle include/linux/jbd2.h:1597 [inline] new_handle fs/jbd2/transaction.c:477 [inline] jbd2__journal_start+0x16f/0x790 fs/jbd2/transaction.c:504 __ext4_journal_start_sb+0x237/0x2d0 fs/ext4/ext4_jbd2.c:105 __ext4_new_inode+0x24bc/0x4250 fs/ext4/ialloc.c:1080 ext4_symlink+0x361/0xd40 fs/ext4/namei.c:3382 vfs_symlink fs/namei.c:4435 [inline] vfs_symlink+0xe9/0x2b0 fs/namei.c:4420 do_symlinkat+0x134/0x2a0 fs/namei.c:4464 __do_sys_symlink fs/namei.c:4486 [inline] __se_sys_symlink fs/namei.c:4484 [inline] __x64_sys_symlink+0x75/0x90 fs/namei.c:4484 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb Freed by task 529: kasan_save_stack+0x26/0x50 mm/kasan/common.c:38 kasan_set_track+0x25/0x30 mm/kasan/common.c:45 kasan_set_free_info+0x24/0x40 mm/kasan/generic.c:370 ____kasan_slab_free mm/kasan/common.c:365 [inline] ____kasan_slab_free mm/kasan/common.c:327 [inline] __kasan_slab_free+0x111/0x150 mm/kasan/common.c:373 kasan_slab_free include/linux/kasan.h:193 [inline] slab_free_hook mm/slub.c:1723 [inline] slab_free_freelist_hook+0x94/0x1a0 mm/slub.c:1749 slab_free mm/slub.c:3519 [inline] kmem_cache_free+0x105/0x250 mm/slub.c:3535 jbd2_free_handle include/linux/jbd2.h:1602 [inline] jbd2_journal_stop+0x496/0xf70 fs/jbd2/transaction.c:1964 __ext4_journal_stop+0xc4/0x1a0 fs/ext4/ext4_jbd2.c:127 ext4_symlink+0x7fc/0xd40 fs/ext4/namei.c:3461 vfs_symlink fs/namei.c:4435 [inline] vfs_symlink+0xe9/0x2b0 fs/namei.c:4420 do_symlinkat+0x134/0x2a0 fs/namei.c:4464 __do_sys_symlink fs/namei.c:4486 [inline] __se_sys_symlink fs/namei.c:4484 [inline] __x64_sys_symlink+0x75/0x90 fs/namei.c:4484 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb The buggy address belongs to the object at ffff88811fab3b00 which belongs to the cache jbd2_journal_handle of size 56 The buggy address is located 36 bytes inside of 56-byte region [ffff88811fab3b00, ffff88811fab3b38) The buggy address belongs to the page: page:ffffea00047eacc0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11fab3 flags: 0x4000000000000200(slab|zone=1) raw: 4000000000000200 0000000000000000 dead000000000122 ffff88810030dc80 raw: 0000000000000000 00000000002e002e 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Reclaimable, gfp_mask 0x112c50(GFP_NOFS|__GFP_NOWARN|__GFP_NORETRY|__GFP_HARDWALL|__GFP_RECLAIMABLE), pid 359, ts 66534873827, free_ts 0 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook mm/page_alloc.c:2604 [inline] prep_new_page+0x1a2/0x310 mm/page_alloc.c:2610 get_page_from_freelist+0x1ce2/0x30a0 mm/page_alloc.c:4484 __alloc_pages+0x2d1/0x2620 mm/page_alloc.c:5776 __alloc_pages_node include/linux/gfp.h:591 [inline] alloc_pages_node include/linux/gfp.h:605 [inline] alloc_pages include/linux/gfp.h:618 [inline] alloc_slab_page mm/slub.c:1793 [inline] allocate_slab+0x39d/0x530 mm/slub.c:1932 new_slab mm/slub.c:1995 [inline] ___slab_alloc.constprop.0+0x3ca/0x890 mm/slub.c:3028 __slab_alloc.constprop.0+0x42/0x80 mm/slub.c:3115 slab_alloc_node mm/slub.c:3206 [inline] slab_alloc mm/slub.c:3248 [inline] kmem_cache_alloc+0x440/0x480 mm/slub.c:3253 kmem_cache_zalloc include/linux/slab.h:723 [inline] jbd2_alloc_handle include/linux/jbd2.h:1597 [inline] new_handle fs/jbd2/transaction.c:477 [inline] jbd2__journal_start+0x16f/0x790 fs/jbd2/transaction.c:504 __ext4_journal_start_sb+0x237/0x2d0 fs/ext4/ext4_jbd2.c:105 __ext4_journal_start fs/ext4/ext4_jbd2.h:326 [inline] ext4_evict_inode+0x72e/0x1700 fs/ext4/inode.c:255 evict+0x2ab/0x610 fs/inode.c:587 iput_final fs/inode.c:1705 [inline] iput.part.0+0x334/0x640 fs/inode.c:1731 iput+0x3f/0x50 fs/inode.c:1721 do_unlinkat+0x354/0x5b0 fs/namei.c:4361 __do_sys_unlink fs/namei.c:4402 [inline] __se_sys_unlink fs/namei.c:4400 [inline] __x64_sys_unlink+0xa5/0xe0 fs/namei.c:4400 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 page_owner free stack trace missing Memory state around the buggy address: ffff88811fab3a00: fb fb fb fb fb fb fc fc fc fc fa fb fb fb fb fb ffff88811fab3a80: fb fc fc fc fc fa fb fb fb fb fb fb fc fc fc fc >ffff88811fab3b00: fa fb fb fb fb fb fb fc fc fc fc fa fb fb fb fb ^ ffff88811fab3b80: fb fb fc fc fc fc fa fb fb fb fb fb fb fc fc fc ffff88811fab3c00: fc fa fb fb fb fb fb fb fc fc fc fc fa fb fb fb ================================================================== invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 529 Comm: syz-executor.2 Tainted: G B 5.15.148-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 RIP: 0010:do_get_write_access+0x56f/0xcf0 fs/jbd2/transaction.c:1102 Code: 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 53 07 00 00 49 8b 75 20 48 8b 7d b0 e8 a8 81 02 00 e9 6c fe ff ff 0f 0b <0f> 0b 48 b8 00 00 00 00 00 fc ff df 4c 89 ca 48 c1 ea 03 80 3c 02 RSP: 0018:ffffc90000dd7a78 EFLAGS: 00010286 RAX: ffff8881097568c0 RBX: dffffc0000000000 RCX: ffffffff81d4bf12 RDX: 0000000000000000 RSI: ffff888124ab0a00 RDI: ffff888124ab0aa0 RBP: ffffc90000dd7af8 R08: ffff888109757448 R09: ffff888109757438 R10: ffffed10200bbc3f R11: 0000000000000001 R12: ffff888109757420 R13: ffff8881005de1f8 R14: ffff88811fab3b00 R15: ffff888109757450 FS: 00007fc7f74a26c0(0000) GS:ffff8881f7400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f657aab3038 CR3: 0000000110cd2000 CR4: 00000000003506b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: jbd2_journal_get_write_access+0xe3/0x140 fs/jbd2/transaction.c:1251 __ext4_journal_get_write_access+0x17c/0x3c0 fs/ext4/ext4_jbd2.c:235 ext4_reserve_inode_write+0x157/0x220 fs/ext4/inode.c:5813 __ext4_mark_inode_dirty+0x10d/0x660 fs/ext4/inode.c:5987 ext4_symlink+0x82f/0xd40 fs/ext4/namei.c:3463 vfs_symlink fs/namei.c:4435 [inline] vfs_symlink+0xe9/0x2b0 fs/namei.c:4420 do_symlinkat+0x134/0x2a0 fs/namei.c:4464 __do_sys_symlink fs/namei.c:4486 [inline] __se_sys_symlink fs/namei.c:4484 [inline] __x64_sys_symlink+0x75/0x90 fs/namei.c:4484 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7fc7f791fba9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fc7f74a20c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000058 RAX: ffffffffffffffda RBX: 00007fc7f7a3ef80 RCX: 00007fc7f791fba9 RDX: 0000000000000000 RSI: 0000000020000180 RDI: 0000000020000140 RBP: 00007fc7f74a2120 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002 R13: 000000000000000b R14: 00007fc7f7a3ef80 R15: 00007ffd266bdd98 Modules linked in: ---[ end trace 3c66958fd09a9657 ]--- RIP: 0010:do_get_write_access+0x56f/0xcf0 fs/jbd2/transaction.c:1102 Code: 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 53 07 00 00 49 8b 75 20 48 8b 7d b0 e8 a8 81 02 00 e9 6c fe ff ff 0f 0b <0f> 0b 48 b8 00 00 00 00 00 fc ff df 4c 89 ca 48 c1 ea 03 80 3c 02 RSP: 0018:ffffc90000dd7a78 EFLAGS: 00010286 RAX: ffff8881097568c0 RBX: dffffc0000000000 RCX: ffffffff81d4bf12 RDX: 0000000000000000 RSI: ffff888124ab0a00 RDI: ffff888124ab0aa0 RBP: ffffc90000dd7af8 R08: ffff888109757448 R09: ffff888109757438 R10: ffffed10200bbc3f R11: 0000000000000001 R12: ffff888109757420 R13: ffff8881005de1f8 R14: ffff88811fab3b00 R15: ffff888109757450 FS: 00007fc7f74a26c0(0000) GS:ffff8881f7400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f657aab3038 CR3: 0000000110cd2000 CR4: 00000000003506b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400