user-mode-linux-user

[uml-user] another gdb trace from a hanging UML process

[Toralf F. <tor...@gm...>]

This is still related to investigate an issue with a hanging UML/crashing UML (32 bit Gentoo Linux as host and guest).

The following output was derived from the gdb - does it contain any helpful information ?
The host kernel is 3.7.1, the guest ran a linux-v3.7-9431-gfa4c95b kernel



0x0805f27c in from_irq_stack (nested=0) at arch/um/kernel/irq.c:462
462             current->stack = to;
(gdb) cont
Continuing.                                                                                                                                            
                                                                                                                                                       
Program received signal SIGSEGV, Segmentation fault.                                                                                                   
0x0805f27c in from_irq_stack (nested=0) at arch/um/kernel/irq.c:462                                                                                    
462             current->stack = to;                                                                                                                   
(gdb) bt                                                                                                                                               
#0  0x0805f27c in from_irq_stack (nested=0) at arch/um/kernel/irq.c:462                                                                                
#1  0x080717dd in hard_handler (sig=<optimized out>, si=0x83fdb0c <cpu0_irqstack+2828>,                                                                
    p=0x83fdb8c <cpu0_irqstack+2956>) at arch/um/os-Linux/signal.c:175                                                                                 
#2  <signal handler called>                                                                                                                            
#3  get_symbol_pos (addr=134759829, symbolsize=0x383e9170, offset=0x383e916c)                                                                          
    at kernel/kallsyms.c:219
#4  0x080b728e in kallsyms_lookup (addr=134759829, symbolsize=0x383e9170, offset=0x383e916c, 
    modname=0x383e9168, namebuf=0x383e91a1 "") at kernel/kallsyms.c:295
#5  0x080b7327 in __sprint_symbol (buffer=0x383e91a1 "", address=134759829, symbol_offset=0, 
    add_offset=1) at kernel/kallsyms.c:354
#6  0x080b74da in sprint_symbol (buffer=0x383e91a1 "", address=134759829) at kernel/kallsyms.c:385
#7  0x082677d7 in symbol_string (buf=0x84c8343 <textbuf.25117+35> "---\n", 
    end=0x84c8700 <cont> "Netdevice 0 (72:ef:3d:35:64:64) : xes 6 to 9)e...No, enabling workaround", 
    ptr=<optimized out>, ext=83 'S', spec=...) at lib/vsprintf.c:537
#8  0x0826814d in pointer (fmt=<optimized out>, buf=0x84c8343 <textbuf.25117+35> "---\n", 
    end=<optimized out>, ptr=0x8084595 <local_bh_enable+69>, spec=...) at lib/vsprintf.c:1054
#9  0x08267f1a in vsnprintf (
    buf=0x84c8320 <textbuf.25117> "\001\064WARNING: at kernel/softirq.c:160 ---\n", size=992, 
    fmt=0x83aec3a "pS()\n", args=0x383e93a0 "\225E\b\b") at lib/vsprintf.c:1442
#10 0x08268467 in vscnprintf (
    buf=0x84c8320 <textbuf.25117> "\001\064WARNING: at kernel/softirq.c:160 ---\n", size=992, 
    fmt=0x83aec25 "\001\064WARNING: at %s:%d %pS()\n", args=0x383e9394 "\034\355:\b\240")
    at lib/vsprintf.c:1548
#11 0x0807eff8 in vprintk_emit (facility=0, level=-1, dict=0x0, dictlen=0, 
    fmt=0x83aec25 "\001\064WARNING: at %s:%d %pS()\n", args=0x383e9394 "\034\355:\b\240")
    at kernel/printk.c:1545
#12 0x0833a37d in printk (fmt=0x83aec25 "\001\064WARNING: at %s:%d %pS()\n") at kernel/printk.c:1687
#13 0x0807d630 in warn_slowpath_common (file=0x83aed1c "kernel/softirq.c", line=160, 
    caller=<optimized out>, taint=9, args=0x0) at kernel/panic.c:413
---Type <return> to continue, or q <return> to quit--- 
#14 0x0807d713 in warn_slowpath_null (file=0x83aed1c "kernel/softirq.c", line=160)
    at kernel/panic.c:454
#15 0x08084595 in _local_bh_enable_ip (ip=<optimized out>) at kernel/softirq.c:160
#16 local_bh_enable () at kernel/softirq.c:187
#17 0x082aa680 in rcu_read_unlock_bh () at include/linux/rcupdate.h:827
#18 dev_queue_xmit (skb=0x381c6e40) at net/core/dev.c:2735
#19 0x082ccaa2 in neigh_hh_output (skb=<optimized out>, hh=<optimized out>)
    at include/net/neighbour.h:356
#20 dst_neigh_output (skb=0x381c6e40, n=0x3841d900, dst=<optimized out>) at include/net/dst.h:412
#21 ip_finish_output2 (skb=0x381c6e40) at net/ipv4/ip_output.c:201
#22 ip_finish_output (skb=<optimized out>) at net/ipv4/ip_output.c:234
#23 0x082ccb43 in ip_output (skb=0x381c6e40) at net/ipv4/ip_output.c:307
#24 0x082cbb23 in dst_output (skb=0x381c6e40) at include/net/dst.h:449
#25 ip_local_out (skb=0x381c6e40) at net/ipv4/ip_output.c:110
#26 0x082cbcce in ip_build_and_send_pkt (skb=0x381c6e40, sk=0x382b0a00, saddr=1090562240, 
    daddr=4261456064, opt=0x0) at net/ipv4/ip_output.c:162
#27 0x082e874a in tcp_v4_conn_request (sk=0x382b0a00, skb=0x381c6780) at net/ipv4/tcp_ipv4.c:1646
#28 0x082df88c in tcp_rcv_state_process (sk=0x382b0a00, skb=0x381c6780, th=0x38269562, len=40)
    at net/ipv4/tcp_input.c:5942
#29 0x082e6577 in tcp_v4_do_rcv (sk=0x382b0a00, skb=0x381c6780) at net/ipv4/tcp_ipv4.c:1890
#30 0x082e90fe in tcp_v4_rcv (skb=0x381c6780) at net/ipv4/tcp_ipv4.c:2030
#31 0x082c82be in ip_local_deliver_finish (skb=0x381c6780) at net/ipv4/ip_input.c:225
#32 ip_local_deliver (skb=0x381c6780) at net/ipv4/ip_input.c:263
#33 0x082c87ca in dst_input (skb=0x381c6780) at include/net/dst.h:455
#34 ip_rcv_finish (skb=0x381c6780) at net/ipv4/ip_input.c:373
#35 ip_rcv (skb=<optimized out>, dev=0x380f2000, pt=0x841fcc0 <ip_packet_type>, orig_dev=0x380f2000)
    at net/ipv4/ip_input.c:451
#36 0x082a7c70 in __netif_receive_skb (skb=0x381c6780) at net/core/dev.c:3456
#37 0x082a7d39 in process_backlog (napi=0x8422600 <softnet_data+64>, quota=1) at net/core/dev.c:3925
---Type <return> to continue, or q <return> to quit---
#38 0x082ab412 in net_rx_action (h=0x84c8fcc <softirq_vec+12>) at net/core/dev.c:4083
#39 0x080843d2 in __do_softirq () at kernel/softirq.c:247
#40 0x08084536 in do_softirq () at kernel/softirq.c:295
#41 0x0808473d in invoke_softirq () at kernel/softirq.c:329
#42 irq_exit () at kernel/softirq.c:348
#43 0x0805ee8a in do_IRQ (irq=5, regs=0x383e9820) at arch/um/kernel/irq.c:295
#44 0x0805ef05 in sigio_handler (sig=29, unused_si=0x0, regs=0x383e9820) at arch/um/kernel/irq.c:53
#45 0x08071b28 in sig_handler_common (sig=29, si=0x0, mc=0x0) at arch/um/os-Linux/signal.c:44
#46 0x08071a4b in unblock_signals () at arch/um/os-Linux/signal.c:282
#47 0x08071bce in set_signals (enable=1) at arch/um/os-Linux/signal.c:302
#48 0x0808453e in arch_local_irq_restore (flags=1)
    at /home/tfoerste/devel/linux/arch/um/include/asm/irqflags.h:16
#49 do_softirq () at kernel/softirq.c:297
#50 0x080845d7 in _local_bh_enable_ip (ip=<optimized out>) at kernel/softirq.c:176
#51 local_bh_enable () at kernel/softirq.c:187
#52 0x082ccac4 in rcu_read_unlock_bh () at include/linux/rcupdate.h:827
#53 ip_finish_output2 (skb=0x3817b0b0) at net/ipv4/ip_output.c:203
#54 ip_finish_output (skb=<optimized out>) at net/ipv4/ip_output.c:234
#55 0x082ccb43 in ip_output (skb=0x3817b0b0) at net/ipv4/ip_output.c:307
#56 0x082cbb23 in dst_output (skb=0x3817b0b0) at include/net/dst.h:449
#57 ip_local_out (skb=0x3817b0b0) at net/ipv4/ip_output.c:110
#58 0x082cbfdd in ip_queue_xmit (skb=0x3817b0b0, fl=0x382b15c8) at net/ipv4/ip_output.c:403
#59 0x082e1e77 in tcp_transmit_skb (sk=0x382b1400, skb=0x3817b0b0, clone_it=<optimized out>, 
    gfp_mask=32) at net/ipv4/tcp_output.c:1106
#60 0x082e288c in tcp_write_xmit (sk=0x382b1400, mss_now=1448, nonagle=1, push_one=0, gfp=32)
    at net/ipv4/tcp_output.c:2029
#61 0x082e2a68 in __tcp_push_pending_frames (sk=0x382b1400, cur_mss=1448, nonagle=1)
    at net/ipv4/tcp_output.c:2068
#62 0x082d4474 in tcp_push (nonagle=<optimized out>, mss_now=1448, flags=64, sk=0x382b1400)
---Type <return> to continue, or q <return> to quit---
    at net/ipv4/tcp.c:636
#63 tcp_sendmsg (iocb=0x383e9d68, sk=0x382b1400, msg=0x383e9d20, size=826) at net/ipv4/tcp.c:1225
#64 0x082f75b3 in inet_sendmsg (iocb=0x383e9d68, sock=0x37cea900, msg=0x383e9d20, size=826)
    at net/ipv4/af_inet.c:784
#65 0x082980ec in __sock_sendmsg_nosec (size=<optimized out>, msg=0x383e9d20, sock=0x37cea900, 
    iocb=0x383e9d68) at net/socket.c:628
#66 __sock_sendmsg (size=<optimized out>, msg=0x383e9d20, sock=0x37cea900, iocb=0x383e9d68)
    at net/socket.c:636
#67 do_sock_write (nr_segs=2, iov=0x383e9e18, iocb=0x383e9d68, msg=0x383e9d20, file=<optimized out>)
    at net/socket.c:974
#68 sock_aio_write (iocb=0x383e9d68, iov=0x383e9e18, nr_segs=2, pos=0) at net/socket.c:989
#69 0x081002f6 in do_sync_readv_writev (filp=0x3838a080, iov=0x383e9e18, nr_segs=2, len=826, 
    ppos=0x383e9e94, fn=0x8297fd0 <sock_aio_write>) at fs/read_write.c:572
#70 0x081005bf in do_readv_writev (type=1, file=0x3838a080, uvector=<optimized out>, nr_segs=2, 
    pos=0x383e9e94) at fs/read_write.c:730
#71 0x08100763 in vfs_writev (file=0x3838a080, vec=0x4b448bd0, vlen=2, pos=0x383e9e94)
    at fs/read_write.c:768
#72 0x08100870 in sys_writev (fd=13, vec=0x4b448bd0, vlen=2) at fs/read_write.c:800
#73 0x08062b22 in handle_syscall (r=0x383ccd50) at arch/um/kernel/skas/syscall.c:35
#74 0x08074f6d in handle_trap (local_using_sysemu=<optimized out>, regs=0x383ccd50, pid=10301)
    at arch/um/os-Linux/skas/process.c:193
#75 userspace (regs=0x383ccd50) at arch/um/os-Linux/skas/process.c:426
#76 0x0805f7fc in fork_handler () at arch/um/kernel/process.c:160
#77 0x00000002 in ?? ()
(


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

Re: [uml-user] another gdb trace from a hanging UML process

[Tully G. <tul...@ar...>]

Toralf Förster wrote:
> This is still related to investigate an issue with a hanging UML/crashing UML (32 bit Gentoo Linux as host and guest).
>
> The following output was derived from the gdb - does it contain any helpful information ?
> The host kernel is 3.7.1, the guest ran a linux-v3.7-9431-gfa4c95b kernel
>
>
>
> 0x0805f27c in from_irq_stack (nested=0) at arch/um/kernel/irq.c:462
> 462             current->stack = to;
> (gdb) cont
> Continuing.                                                                                                                                            
>                                                                                                                                                        
> Program received signal SIGSEGV, Segmentation fault.                                                                                                   
> 0x0805f27c in from_irq_stack (nested=0) at arch/um/kernel/irq.c:462                                                                                    
> 462             current->stack = to;                                                                                                                   
> (gdb) bt                                                                                                                                               
> #0  0x0805f27c in from_irq_stack (nested=0) at arch/um/kernel/irq.c:462                                                                                
> #1  0x080717dd in hard_handler (sig=<optimized out>, si=0x83fdb0c <cpu0_irqstack+2828>,                                                                
>     p=0x83fdb8c <cpu0_irqstack+2956>) at arch/um/os-Linux/signal.c:175                                                                                 
> #2  <signal handler called>                                                                                                                            
> #3  get_symbol_pos (addr=134759829, symbolsize=0x383e9170, offset=0x383e916c)                                                                          
>     at kernel/kallsyms.c:219
> #4  0x080b728e in kallsyms_lookup (addr=134759829, symbolsize=0x383e9170, offset=0x383e916c, 
>     modname=0x383e9168, namebuf=0x383e91a1 "") at kernel/kallsyms.c:295
> #5  0x080b7327 in __sprint_symbol (buffer=0x383e91a1 "", address=134759829, symbol_offset=0, 
>     add_offset=1) at kernel/kallsyms.c:354
> #6  0x080b74da in sprint_symbol (buffer=0x383e91a1 "", address=134759829) at kernel/kallsyms.c:385
> #7  0x082677d7 in symbol_string (buf=0x84c8343 <textbuf.25117+35> "---\n", 
>     end=0x84c8700 <cont> "Netdevice 0 (72:ef:3d:35:64:64) : xes 6 to 9)e...No, enabling workaround", 
>     ptr=<optimized out>, ext=83 'S', spec=...) at lib/vsprintf.c:537
> #8  0x0826814d in pointer (fmt=<optimized out>, buf=0x84c8343 <textbuf.25117+35> "---\n", 
>     end=<optimized out>, ptr=0x8084595 <local_bh_enable+69>, spec=...) at lib/vsprintf.c:1054
> #9  0x08267f1a in vsnprintf (
>     buf=0x84c8320 <textbuf.25117> "\001\064WARNING: at kernel/softirq.c:160 ---\n", size=992, 
>     fmt=0x83aec3a "pS()\n", args=0x383e93a0 "\225E\b\b") at lib/vsprintf.c:1442
> #10 0x08268467 in vscnprintf (
>     buf=0x84c8320 <textbuf.25117> "\001\064WARNING: at kernel/softirq.c:160 ---\n", size=992, 
>     fmt=0x83aec25 "\001\064WARNING: at %s:%d %pS()\n", args=0x383e9394 "\034\355:\b\240")
>     at lib/vsprintf.c:1548
> #11 0x0807eff8 in vprintk_emit (facility=0, level=-1, dict=0x0, dictlen=0, 
>     fmt=0x83aec25 "\001\064WARNING: at %s:%d %pS()\n", args=0x383e9394 "\034\355:\b\240")
>     at kernel/printk.c:1545
> #12 0x0833a37d in printk (fmt=0x83aec25 "\001\064WARNING: at %s:%d %pS()\n") at kernel/printk.c:1687
> #13 0x0807d630 in warn_slowpath_common (file=0x83aed1c "kernel/softirq.c", line=160, 
>     caller=<optimized out>, taint=9, args=0x0) at kernel/panic.c:413
> ---Type <return> to continue, or q <return> to quit--- 
> #14 0x0807d713 in warn_slowpath_null (file=0x83aed1c "kernel/softirq.c", line=160)
>     at kernel/panic.c:454
> #15 0x08084595 in _local_bh_enable_ip (ip=<optimized out>) at kernel/softirq.c:160
> #16 local_bh_enable () at kernel/softirq.c:187
> #17 0x082aa680 in rcu_read_unlock_bh () at include/linux/rcupdate.h:827
> #18 dev_queue_xmit (skb=0x381c6e40) at net/core/dev.c:2735
> #19 0x082ccaa2 in neigh_hh_output (skb=<optimized out>, hh=<optimized out>)
>     at include/net/neighbour.h:356
> #20 dst_neigh_output (skb=0x381c6e40, n=0x3841d900, dst=<optimized out>) at include/net/dst.h:412
> #21 ip_finish_output2 (skb=0x381c6e40) at net/ipv4/ip_output.c:201
> #22 ip_finish_output (skb=<optimized out>) at net/ipv4/ip_output.c:234
> #23 0x082ccb43 in ip_output (skb=0x381c6e40) at net/ipv4/ip_output.c:307
> #24 0x082cbb23 in dst_output (skb=0x381c6e40) at include/net/dst.h:449
> #25 ip_local_out (skb=0x381c6e40) at net/ipv4/ip_output.c:110
> #26 0x082cbcce in ip_build_and_send_pkt (skb=0x381c6e40, sk=0x382b0a00, saddr=1090562240, 
>     daddr=4261456064, opt=0x0) at net/ipv4/ip_output.c:162
> #27 0x082e874a in tcp_v4_conn_request (sk=0x382b0a00, skb=0x381c6780) at net/ipv4/tcp_ipv4.c:1646
> #28 0x082df88c in tcp_rcv_state_process (sk=0x382b0a00, skb=0x381c6780, th=0x38269562, len=40)
>     at net/ipv4/tcp_input.c:5942
> #29 0x082e6577 in tcp_v4_do_rcv (sk=0x382b0a00, skb=0x381c6780) at net/ipv4/tcp_ipv4.c:1890
> #30 0x082e90fe in tcp_v4_rcv (skb=0x381c6780) at net/ipv4/tcp_ipv4.c:2030
> #31 0x082c82be in ip_local_deliver_finish (skb=0x381c6780) at net/ipv4/ip_input.c:225
> #32 ip_local_deliver (skb=0x381c6780) at net/ipv4/ip_input.c:263
> #33 0x082c87ca in dst_input (skb=0x381c6780) at include/net/dst.h:455
> #34 ip_rcv_finish (skb=0x381c6780) at net/ipv4/ip_input.c:373
> #35 ip_rcv (skb=<optimized out>, dev=0x380f2000, pt=0x841fcc0 <ip_packet_type>, orig_dev=0x380f2000)
>     at net/ipv4/ip_input.c:451
> #36 0x082a7c70 in __netif_receive_skb (skb=0x381c6780) at net/core/dev.c:3456
> #37 0x082a7d39 in process_backlog (napi=0x8422600 <softnet_data+64>, quota=1) at net/core/dev.c:3925
> ---Type <return> to continue, or q <return> to quit---
> #38 0x082ab412 in net_rx_action (h=0x84c8fcc <softirq_vec+12>) at net/core/dev.c:4083
> #39 0x080843d2 in __do_softirq () at kernel/softirq.c:247
> #40 0x08084536 in do_softirq () at kernel/softirq.c:295
> #41 0x0808473d in invoke_softirq () at kernel/softirq.c:329
> #42 irq_exit () at kernel/softirq.c:348
> #43 0x0805ee8a in do_IRQ (irq=5, regs=0x383e9820) at arch/um/kernel/irq.c:295
> #44 0x0805ef05 in sigio_handler (sig=29, unused_si=0x0, regs=0x383e9820) at arch/um/kernel/irq.c:53
> #45 0x08071b28 in sig_handler_common (sig=29, si=0x0, mc=0x0) at arch/um/os-Linux/signal.c:44
> #46 0x08071a4b in unblock_signals () at arch/um/os-Linux/signal.c:282
> #47 0x08071bce in set_signals (enable=1) at arch/um/os-Linux/signal.c:302
> #48 0x0808453e in arch_local_irq_restore (flags=1)
>     at /home/tfoerste/devel/linux/arch/um/include/asm/irqflags.h:16
> #49 do_softirq () at kernel/softirq.c:297
> #50 0x080845d7 in _local_bh_enable_ip (ip=<optimized out>) at kernel/softirq.c:176
> #51 local_bh_enable () at kernel/softirq.c:187
> #52 0x082ccac4 in rcu_read_unlock_bh () at include/linux/rcupdate.h:827
> #53 ip_finish_output2 (skb=0x3817b0b0) at net/ipv4/ip_output.c:203
> #54 ip_finish_output (skb=<optimized out>) at net/ipv4/ip_output.c:234
> #55 0x082ccb43 in ip_output (skb=0x3817b0b0) at net/ipv4/ip_output.c:307
> #56 0x082cbb23 in dst_output (skb=0x3817b0b0) at include/net/dst.h:449
> #57 ip_local_out (skb=0x3817b0b0) at net/ipv4/ip_output.c:110
> #58 0x082cbfdd in ip_queue_xmit (skb=0x3817b0b0, fl=0x382b15c8) at net/ipv4/ip_output.c:403
> #59 0x082e1e77 in tcp_transmit_skb (sk=0x382b1400, skb=0x3817b0b0, clone_it=<optimized out>, 
>     gfp_mask=32) at net/ipv4/tcp_output.c:1106
> #60 0x082e288c in tcp_write_xmit (sk=0x382b1400, mss_now=1448, nonagle=1, push_one=0, gfp=32)
>     at net/ipv4/tcp_output.c:2029
> #61 0x082e2a68 in __tcp_push_pending_frames (sk=0x382b1400, cur_mss=1448, nonagle=1)
>     at net/ipv4/tcp_output.c:2068
> #62 0x082d4474 in tcp_push (nonagle=<optimized out>, mss_now=1448, flags=64, sk=0x382b1400)
> ---Type <return> to continue, or q <return> to quit---
>     at net/ipv4/tcp.c:636
> #63 tcp_sendmsg (iocb=0x383e9d68, sk=0x382b1400, msg=0x383e9d20, size=826) at net/ipv4/tcp.c:1225
> #64 0x082f75b3 in inet_sendmsg (iocb=0x383e9d68, sock=0x37cea900, msg=0x383e9d20, size=826)
>     at net/ipv4/af_inet.c:784
> #65 0x082980ec in __sock_sendmsg_nosec (size=<optimized out>, msg=0x383e9d20, sock=0x37cea900, 
>     iocb=0x383e9d68) at net/socket.c:628
> #66 __sock_sendmsg (size=<optimized out>, msg=0x383e9d20, sock=0x37cea900, iocb=0x383e9d68)
>     at net/socket.c:636
> #67 do_sock_write (nr_segs=2, iov=0x383e9e18, iocb=0x383e9d68, msg=0x383e9d20, file=<optimized out>)
>     at net/socket.c:974
> #68 sock_aio_write (iocb=0x383e9d68, iov=0x383e9e18, nr_segs=2, pos=0) at net/socket.c:989
> #69 0x081002f6 in do_sync_readv_writev (filp=0x3838a080, iov=0x383e9e18, nr_segs=2, len=826, 
>     ppos=0x383e9e94, fn=0x8297fd0 <sock_aio_write>) at fs/read_write.c:572
> #70 0x081005bf in do_readv_writev (type=1, file=0x3838a080, uvector=<optimized out>, nr_segs=2, 
>     pos=0x383e9e94) at fs/read_write.c:730
> #71 0x08100763 in vfs_writev (file=0x3838a080, vec=0x4b448bd0, vlen=2, pos=0x383e9e94)
>     at fs/read_write.c:768
> #72 0x08100870 in sys_writev (fd=13, vec=0x4b448bd0, vlen=2) at fs/read_write.c:800
> #73 0x08062b22 in handle_syscall (r=0x383ccd50) at arch/um/kernel/skas/syscall.c:35
> #74 0x08074f6d in handle_trap (local_using_sysemu=<optimized out>, regs=0x383ccd50, pid=10301)
>     at arch/um/os-Linux/skas/process.c:193
> #75 userspace (regs=0x383ccd50) at arch/um/os-Linux/skas/process.c:426
> #76 0x0805f7fc in fork_handler () at arch/um/kernel/process.c:160
> #77 0x00000002 in ?? ()
> (
>
>
Hi,

I increased the stack size (CONFIG_KERNEL_STACK_ORDER) in the guest
kernel and the problem went away.  I think I had a very similar problem
under 32 bit with Gentoo host/guest.

Tully Gray.

Re: [uml-user] another gdb trace from a hanging UML process

[Toralf F. <tor...@gm...>]

On 01/02/2013 06:53 AM, Tully Gray wrote:
> Toralf Förster wrote:
>> This is still related to investigate an issue with a hanging UML/crashing UML (32 bit Gentoo Linux as host and guest).
>>
>> The following output was derived from the gdb - does it contain any helpful information ?
>> The host kernel is 3.7.1, the guest ran a linux-v3.7-9431-gfa4c95b kernel
>>
>>
>>
>> 0x0805f27c in from_irq_stack (nested=0) at arch/um/kernel/irq.c:462
>> 462             current->stack = to;
>> (gdb) cont
>> Continuing.                                                                                                                                            
>>                                                                                                                                                        
>> Program received signal SIGSEGV, Segmentation fault.                                                                                                   
>> 0x0805f27c in from_irq_stack (nested=0) at arch/um/kernel/irq.c:462                                                                                    
>> 462             current->stack = to;                                                                                                                   
>> (gdb) bt                                                                                                                                               
>> #0  0x0805f27c in from_irq_stack (nested=0) at arch/um/kernel/irq.c:462                                                                                
>> #1  0x080717dd in hard_handler (sig=<optimized out>, si=0x83fdb0c <cpu0_irqstack+2828>,                                                                
>>     p=0x83fdb8c <cpu0_irqstack+2956>) at arch/um/os-Linux/signal.c:175                                                                                 
>> #2  <signal handler called>                                                                                                                            
>> #75 userspace (regs=0x383ccd50) at arch/um/os-Linux/skas/process.c:426
>> #76 0x0805f7fc in fork_handler () at arch/um/kernel/process.c:160
>> #77 0x00000002 in ?? ()
>> (

> Hi,
> 
> I increased the stack size (CONFIG_KERNEL_STACK_ORDER) in the guest
> kernel and the problem went away.  I think I had a very similar problem
> under 32 bit with Gentoo host/guest.

Well, if I set that value to "3", then the issue happens much more
rarely than before.

Setting it to "5" gives here at an 32 bit Gentoo every time during start :

Checking that host ptys support output SIGIO...Yes
Checking that host ptys support SIGIO on close...No, enabling workaround
Kernel panic - not syncing: Kernel mode signal 4
0845f754:  [<0833e1a8>] dump_stack+0x22/0x24
0845f76c:  [<0833e224>] panic+0x7a/0x18b
0845f794:  [<0806224c>] relay_signal+0x4c/0x150
0845f840:  [<08071ab8>] sig_handler_common+0xb8/0xe0
0845fac4:  [<08071bfd>] sig_handler+0x3d/0x50
0845fad4:  [<0807174b>] hard_handler+0x6b/0xa0
0845fafc:  [<b776640c>] 0xb776640c


EIP: 0073:[<b7766424>] CPU: 0 Not tainted ESP: 007b:bfb3d5e4 EFLAGS:
00000286
    Not tainted
EAX: 00000000 EBX: 00001cb3 ECX: 00000013 EDX: 00001cb3
ESI: 00001caf EDI: bfb3d678 EBP: bfb3d618 DS: 007b ES: 007b
0845f708:  [<0807957f>] show_regs+0x10f/0x120
0845f724:  [<0806255c>] panic_exit+0x2c/0x50
0845f734:  [<0809e158>] notifier_call_chain+0x38/0x60
0845f75c:  [<0809e2a3>] atomic_notifier_call_chain+0x23/0x30
0845f76c:  [<0833e24c>] panic+0xa2/0x18b
0845f794:  [<0806224c>] relay_signal+0x4c/0x150
0845f840:  [<08071ab8>] sig_handler_common+0xb8/0xe0
0845fac4:  [<08071bfd>] sig_handler+0x3d/0x50
0845fad4:  [<0807174b>] hard_handler+0x6b/0xa0
0845fafc:  [<b776640c>] 0xb776640c



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

Re: [uml-user] another gdb trace from a hanging UML process

[Toralf F. <tor...@gm...>]

On 01/02/2013 06:53 AM, Tully Gray wrote:
> 
> I increased the stack size (CONFIG_KERNEL_STACK_ORDER) in the guest
> kernel and the problem went away.  I think I had a very similar problem
> under 32 bit with Gentoo host/guest.

with a value of 2 it seems now to work fine.

Thanks again for the hint.



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