>> Hi, >> >> I was doing some fuzzing with http://code.google.com/p/iknowthis/ and >> my system pretty quickly crashes with the BUG() below. > > So it is a repeatable crash? Not in a sense that I can provide you with a sequence of syscalls that led to this state. Generally it repeats after some time (<12 hours on 2 intel-core) of running the http://code.google.com/p/iknowthis/source/browse/#svn/trunk >> - Even if it's just BUG() it renders my system unusable (I'm able to >> type a few characters on the virtual terminal at most) >> - Judging from the stacktrace it's sys_madvise(..., ..., MADV_REMOVE) >> - I'm testing with ubuntu's 2.6.35-22-server#35 but I got similar >> results with 2.6.32 some time ago > > It is. > >> - I'm posting this cause diving into linux mm spaghetti code might be >> not a trivial task, but if nobody can see anything obvious in a day or >> so, I'll try to debug it mysel >> - I'm unable to provide a testcase by now, nor any usable state of the >> crashing process, cause the system becomes unusable >> - It crashes both linux-kernel working on a physical machine as well >> as on the VirtualBox emulator >> - I'm usually waiting from 0.5h to 12h for this crash to appear, I >> think it could be speed up greatly by disabling any irrelevant >> syscalls in the fuzzer >> >> [25142.286531] kernel BUG at /build/buildd/linux-2.6.35/mm/filemap.c:128! > > That's > > Â Â Â ÂBUG_ON(page_mapped(page)); > > in __remove_from_page_cache(). ÂThat state is worth a BUG(). > >> [25142.290627] invalid opcode: 0000 [#2] SMP >> [25142.290627] last sysfs file: /sys/fs/ext4/sda1/lifetime_write_kbytes >> [25142.301039] CPU 1 >> [25142.301039] Modules linked in: dccp_ipv6 decnet llc2 x25 pppoe >> pppox irda crc_ccitt dccp_ipv4 dccp ipx p8023 rds af_key netrom econet >> can atm l2cap bluetooth appletalk rose ax25 nouveau snd_hda_codec_idt >> ttm snd_hda_intel drm_kms_helper snd_hda_codec led_class drm psmouse >> snd_hwdep ppdev snd_pcm snd_timer i2c_algo_bit serio_raw i82975x_edac >> snd parport_pc lp soundcore edac_core snd_page_alloc parport dcdbas >> floppy ahci firewire_ohci firewire_core crc_itu_t tg3 libahci >> [25142.301039] >> [25142.301039] Pid: 22612, comm: iknowthis Tainted: G Â Â ÂD W >> 2.6.35-22-server #35-Ubuntu 0GH911/Precision WorkStation 390 >> [25142.301039] RIP: 0010:[<ffffffff81101645>] Â[<ffffffff81101645>] >> __remove_from_page_cache+0xd5/0xe0 >> [25142.367617] RSP: 0000:ffff8800cb8a3cf8 ÂEFLAGS: 00010002 >> [25142.367617] RAX: 0100000000100029 RBX: ffffea0002159670 RCX: 0000000000000000 >> [25142.367617] RDX: 0000000000000001 RSI: 0000000000000016 RDI: ffff880100000700 >> [25142.367617] RBP: ffff8800cb8a3d08 R08: 0000000000000018 R09: 0000000000000000 >> [25142.367617] R10: ffffea0002159678 R11: 0000000000000000 R12: ffff8800cb865188 >> [25142.367617] R13: ffff8800cb865188 R14: ffff8800cb8a3d88 R15: 0000000000000000 >> [25142.367617] FS: Â0000000000000000(0000) GS:ffff880001e40000(0063) >> knlGS:00000000f75276c0 >> [25142.367617] CS: Â0010 DS: 002b ES: 002b CR0: 000000008005003b >> [25142.367617] CR2: 00000000080ba1fc CR3: 000000012091d000 CR4: 00000000000006e0 >> [25142.367617] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 >> [25142.367617] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 >> [25142.367617] Process iknowthis (pid: 22612, threadinfo >> ffff8800cb8a2000, task ffff8800cb9516e0) >> [25142.367617] Stack: >> [25142.367617] Âffffea0002159670 ffff8800cb8651a0 ffff8800cb8a3d28 >> ffffffff81101686 >> [25142.367617] <0> ffffea0002159670 ffff8800cb865188 ffff8800cb8a3d48 >> ffffffff8110c6d9 >> [25142.367617] <0> 0000000000000001 0000000000000008 ffff8800cb8a3e38 >> ffffffff8110cce0 >> [25142.367617] Call Trace: >> [25142.367617] Â[<ffffffff81101686>] remove_from_page_cache+0x36/0x60 >> [25142.367617] Â[<ffffffff8110c6d9>] truncate_inode_page+0x79/0xb0 >> [25142.367617] Â[<ffffffff8110cce0>] truncate_inode_pages_range+0x160/0x460 >> [25142.367617] Â[<ffffffff81121250>] ? unmap_mapping_range+0xb0/0x160 >> [25142.367617] Â[<ffffffff81121398>] vmtruncate_range+0x98/0x100 >> [25142.367617] Â[<ffffffff8111ae5a>] madvise_vma+0x17a/0x210 >> [25142.367617] Â[<ffffffff8111b055>] sys_madvise+0x165/0x290 >> [25142.367617] Â[<ffffffff810467c3>] ia32_sysret+0x0/0x5 >> [25142.367617] Code: 00 00 e8 1f 8a 1c 00 48 89 df 57 9d 0f 1f 44 00 >> 00 5b 41 5c c9 c3 be 16 00 00 00 48 89 df e8 a3 68 01 00 48 8b 03 e9 >> 71 ff ff ff <0f> 0b eb fe eb 05 90 90 90 90 90 55 48 89 e5 48 83 ec 10 >> 48 89 >> [25142.367617] RIP Â[<ffffffff81101645>] __remove_from_page_cache+0xd5/0xe0 >> [25142.367617] ÂRSP <ffff8800cb8a3cf8> >> [25142.367617] ---[ end trace a262aa785b417723 ]--- > > -- Robert ÅwiÄcki -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: <a href