[uml-devel] fuzzed UML hangs at another place

[uml-devel] fuzzed UML hangs at another place

[Toralf Förster]

While trying to reproduce an UML hang in mm/*radix* I realized with recent kernels and trinity,
that a 32 bit Gentoo Linux UML often now just hangs here :


tfoerste@n22 ~ $ pgrep linux | while read pid; do echo; echo $pid;  sudo gdb /home/tfoerste/devel/linux/linux $pid -n -batch -ex bt; done
                                                                                                                                                       
8067                                                                                                                                                   
0xb7762424 in __kernel_vsyscall ()                                                                                                                     
#0  0xb7762424 in __kernel_vsyscall ()                                                                                                                 
#1  0x083d59ef in __nanosleep_nocancel ()                                                                                                              
#2  0x0807269c in idle_sleep (nsecs=602496466104653440) at arch/um/os-Linux/time.c:183                                                                 
#3  0x0805fc2f in arch_cpu_idle () at arch/um/kernel/process.c:208                                                                                     
#4  0x080a8901 in cpu_idle_loop () at kernel/cpu/idle.c:98                                                                                             
#5  cpu_startup_entry (state=CPUHP_ONLINE) at kernel/cpu/idle.c:140                                                                                    
#6  0x08421b22 in rest_init () at init/main.c:401                                                                                                      
#7  0x080487e1 in start_kernel () at init/main.c:655                                                                                                   
#8  0x08049e09 in start_kernel_proc (unused=0x0) at arch/um/kernel/skas/process.c:46                                                                   
#9  0x0805f7eb in new_thread_handler () at arch/um/kernel/process.c:129
#10 0x00000000 in ?? ()

8074

warning: process 8074 is a cloned process
0xb7762424 in __kernel_vsyscall ()
#0  0xb7762424 in __kernel_vsyscall ()
#1  0x083d9186 in syscall ()
#2  0x0806e891 in io_getevents (events=<optimized out>, ctx_id=<optimized out>, min_nr=<optimized out>, nr=<optimized out>, timeout=<optimized out>) at arch/um/os-Linux/aio.c:49
#3  aio_thread (arg=0x0) at arch/um/os-Linux/aio.c:109
#4  0x083da20e in clone ()

8075

warning: process 8075 is a cloned process
0xb7762424 in __kernel_vsyscall ()
#0  0xb7762424 in __kernel_vsyscall ()
#1  0x083d6ff2 in __read_nocancel ()
#2  0x0806f42f in read (__nbytes=<optimized out>, __buf=<optimized out>, __fd=<optimized out>) at /usr/include/bits/unistd.h:45
#3  os_read_file (fd=-512, buf=0xfffffe00, len=-512) at arch/um/os-Linux/file.c:253
#4  0x0806bb2c in io_thread (arg=0x0) at arch/um/drivers/ubd_kern.c:1482
#5  0x083da20e in clone ()

8076

warning: process 8076 is a cloned process
0xb7762424 in __kernel_vsyscall ()
#0  0xb7762424 in __kernel_vsyscall ()
#1  0x083d7e6c in poll ()
#2  0x08071144 in write_sigio_thread (unused=0x0) at arch/um/os-Linux/sigio.c:61
#3  0x083da20e in clone ()

8077
warning: process 8077 is a zombie - the process has already terminated
ptrace: Operation not permitted.
/home/tfoerste/8077: No such file or directory.
No stack.

...


A ssh into the UML is now no longer possible and no syslog messages any longer, 
I do just kill it therefore.

-- 
MfG/Sincerely
Toralf Förster
pgp finger print: 7B1A 07F4 EC82 0F90 D4C2 8936 872A E508 7DB6 9DA3

------------------------------------------------------------------------------
Shape the Mobile Experience: Free Subscription
Software experts and developers: Be at the forefront of tech innovation.
Intel(R) Software Adrenaline delivers strategic insight and game-changing 
conversations that shape the rapidly evolving mobile landscape. Sign up now. 
http://pubads.g.doubleclick.net/gampad/clk?id=63431311&iu=/4140/ostg.clktrk
_______________________________________________
User-mode-linux-devel mailing list
User-mode-linux-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel