On 08/03/2014 08:42 PM, Theodore Ts'o wrote: > On Sun, Aug 03, 2014 at 03:52:18PM +0200, Toralf Förster wrote: >> Hello, >> >> fuzzying a 32 bit stable Gentoo x86 linux with trinity (and without excluding the munmap syscall but it might be independed from this) gives within a 32 bit user mode linux guest : > > The problem with these sorts of trinity bug reports is that we have no > idea which syscall or set of syscalls might have corrupted kernel > state to the point where the kernel started malfunctioning. > > Sometimes, a trinity induced bug is obvious, when it causes a system > call to immediately access an illegal memory location. But if it > causes some more subtle corruption, possibly in a completely unrelated > subsystem, figuring out what actually happened can be close to > impossible. > > So there's not much I can do with this sort of bug report. If you can > easily repeat it, and you can dump out the system call stream, we > might be able to make a smaller reproduction case, at which point > trying to debug this sort of failure would be tractable. > > Cheers, > > - Ted > ok, fair enough. BTW may I just ask, if the following (same 32 bit system, host and UML guest are both at v3.16, 4 trinity childs hammering victims files in a ramdisk within the uML guest) matches the above too ? Or does the BUG output here more helpful data ? : Kernel panic - not syncing: BUG! CPU: 0 PID: 105 Comm: kworker/u2:2 Not tainted 3.16.0 #2 Workqueue: writeback bdi_writeback_workfn (flush-98:0) Stack: 085be12e 085be12e 00000003 086e8547 0000000c 000002b3 85177cc4 85177c74 085015c3 00000000 85177c48 85177c9c 084fd6dd 085c9dc0 08727180 085bae4a 85177ca8 00000000 0000000c 000002b3 85177cc4 85177d10 0818ec0f 085bae4a Call Trace: [<085015c3>] dump_stack+0x26/0x28 [<084fd6dd>] panic+0x8f/0x1a9 [<0818ec0f>] mpage_release_unused_pages+0x11f/0x1b0 [<0819395a>] ext4_writepages+0x42a/0x640 [<080d87e5>] do_writepages+0x25/0x50 [<0812fd2c>] __writeback_single_inode+0x3c/0xf0 [<08130064>] writeback_sb_inodes+0x1d4/0x320 [<08130214>] __writeback_inodes_wb+0x64/0xa0 [<08130501>] wb_writeback+0xf1/0x190 [<081308a2>] bdi_writeback_workfn+0xa2/0x2d0 [<08504c56>] ? _raw_spin_unlock_irq+0x16/0x20 [<0809e30c>] ? finish_task_switch.constprop.52+0x3c/0x90 [<08091474>] process_one_work+0x184/0x2f0 [<080918da>] worker_thread+0x2fa/0x540 [<08504c3c>] ? _raw_spin_unlock_irqrestore+0x1c/0x20 [<08502d65>] ? schedule+0x55/0x60 [<080915e0>] ? worker_thread+0x0/0x540 [<080971b6>] kthread+0xd6/0xe0 [<0805f68b>] new_thread_handler+0x6b/0x90 -- Toralf -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
