Fuzz testing a 32 bit x86 Gentoo UML guest (especially NFSv4 files, nfs sserver and client runs within the UML guest) with current git kernel brought the guest into a state, where no ssh login is any longer possible.
At the host side I can see that the linux processes are still running. I attached the gdb to the linux processes at the host (even 32 bit x86 Gentoo). I do get nearly all the time: Thread 1 (process 4252): #0 0xb7736aec in __kernel_vsyscall () #1 0x08496faf in __nanosleep_nocancel () at ../sysdeps/unix/syscall-template.S:81 #2 0x08073124 in idle_sleep (nsecs=606859328243668608) at arch/um/os-Linux/time.c:183 #3 0x08060b3f in arch_cpu_idle () at arch/um/kernel/process.c:208 #4 0x080a5405 in cpuidle_idle_call () at kernel/sched/idle.c:120 #5 cpu_idle_loop () at kernel/sched/idle.c:224 #6 cpu_startup_entry (state=CPUHP_ONLINE) at kernel/sched/idle.c:272 #7 0x084e16d2 in rest_init () at init/main.c:419 #8 0x0804892e in start_kernel () at init/main.c:679 #9 0x08049fc9 in start_kernel_proc (unused=0x0) at arch/um/kernel/skas/process.c:46 #10 0x0806064b in new_thread_handler () at arch/um/kernel/process.c:129 #11 0x00000000 in ?? () ... but at least one time I got: 0x08108de3 in __put_super (sb=0x86a60000) at fs/super.c:246 246 if (!--sb->s_count) { Thread 1 (process 4252): #0 0x08108de3 in __put_super (sb=0x86a60000) at fs/super.c:246 #1 0x081096ac in put_super (sb=<optimized out>) at fs/super.c:262 #2 drop_super (sb=0x86a60000) at fs/super.c:487 #3 0x0812a337 in __writeback_inodes_wb (wb=0x8421c09c, work=0x1) at fs/fs-writeback.c:733 #4 0x0812a479 in wb_writeback (wb=0x8421c09c, work=0x869d7efc) at fs/fs-writeback.c:863 #5 0x0812a74e in wb_check_background_flush (wb=<optimized out>) at fs/fs-writeback.c:944 #6 wb_do_writeback (wb=<optimized out>) at fs/fs-writeback.c:1014 #7 bdi_writeback_workfn (work=0x8421c0a8) at fs/fs-writeback.c:1043 #8 0x08090d11 in process_one_work (worker=0x84325000, work=0x8421c0a8) at kernel/workqueue.c:2081 #9 0x0809116a in worker_thread (__worker=0x84325000) at kernel/workqueue.c:2212 #10 0x08096806 in kthread (_create=0x84207410) at kernel/kthread.c:207 #11 0x0806064b in new_thread_handler () at arch/um/kernel/process.c:129 #12 0x00000000 in ?? () ... Now I'm wondering if this is an issue which is worth to be debugged or whether I just should ignore it. BTW the nsecs of 2 gdb calls in a row are identical since few minutes : 606859328243668608 before the value was : 606859328233668608 -- Toralf ------------------------------------------------------------------------------ Want fast and easy access to all the code in your enterprise? Index and search up to 200,000 lines of code with a free copy of Black Duck Code Sight - the same software that powers the world's largest code search on Ohloh, the Black Duck Open Hub! Try it now. http://p.sf.net/sfu/bds _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel