Re: [qemu-s390x] [Qemu-devel] [BUG] I/O thread segfault for QEMU on s390x

[Farhan Ali]

On 03/05/2018 06:03 AM, Stefan Hajnoczi wrote:
> Please include the following gdb output:
>
>    (gdb) disas swapcontext
>    (gdb) i r
>
> That way it's possible to see which instruction faulted and which
> registers were being accessed.


here is the disas out for swapcontext, this is on a coredump with 
debugging symbols enabled for qemu. So the addresses from the previous 
dump is a little different.


(gdb) disas swapcontext
Dump of assembler code for function swapcontext:
   0x000003ff90751fb8 <+0>:       lgr     %r1,%r2
   0x000003ff90751fbc <+4>:       lgr     %r0,%r3
   0x000003ff90751fc0 <+8>:       stfpc   248(%r1)
   0x000003ff90751fc4 <+12>:      std     %f0,256(%r1)
   0x000003ff90751fc8 <+16>:      std     %f1,264(%r1)
   0x000003ff90751fcc <+20>:      std     %f2,272(%r1)
   0x000003ff90751fd0 <+24>:      std     %f3,280(%r1)
   0x000003ff90751fd4 <+28>:      std     %f4,288(%r1)
   0x000003ff90751fd8 <+32>:      std     %f5,296(%r1)
   0x000003ff90751fdc <+36>:      std     %f6,304(%r1)
   0x000003ff90751fe0 <+40>:      std     %f7,312(%r1)
   0x000003ff90751fe4 <+44>:      std     %f8,320(%r1)
   0x000003ff90751fe8 <+48>:      std     %f9,328(%r1)
   0x000003ff90751fec <+52>:      std     %f10,336(%r1)
   0x000003ff90751ff0 <+56>:      std     %f11,344(%r1)
   0x000003ff90751ff4 <+60>:      std     %f12,352(%r1)
   0x000003ff90751ff8 <+64>:      std     %f13,360(%r1)
   0x000003ff90751ffc <+68>:      std     %f14,368(%r1)
   0x000003ff90752000 <+72>:      std     %f15,376(%r1)
   0x000003ff90752004 <+76>:      slgr    %r2,%r2
   0x000003ff90752008 <+80>:      stam    %a0,%a15,184(%r1)
   0x000003ff9075200c <+84>:      stmg    %r0,%r15,56(%r1)
   0x000003ff90752012 <+90>:      la      %r2,2
   0x000003ff90752016 <+94>:      lgr     %r5,%r0
   0x000003ff9075201a <+98>:      la      %r3,384(%r5)
   0x000003ff9075201e <+102>:     la      %r4,384(%r1)
   0x000003ff90752022 <+106>:     lghi    %r5,8
   0x000003ff90752026 <+110>:     svc     175
   0x000003ff90752028 <+112>:     lgr     %r5,%r0
=> 0x000003ff9075202c <+116>:  lfpc    248(%r5)
   0x000003ff90752030 <+120>:     ld      %f0,256(%r5)
   0x000003ff90752034 <+124>:     ld      %f1,264(%r5)
   0x000003ff90752038 <+128>:     ld      %f2,272(%r5)
   0x000003ff9075203c <+132>:     ld      %f3,280(%r5)
   0x000003ff90752040 <+136>:     ld      %f4,288(%r5)
   0x000003ff90752044 <+140>:     ld      %f5,296(%r5)
   0x000003ff90752048 <+144>:     ld      %f6,304(%r5)
   0x000003ff9075204c <+148>:     ld      %f7,312(%r5)
   0x000003ff90752050 <+152>:     ld      %f8,320(%r5)
   0x000003ff90752054 <+156>:     ld      %f9,328(%r5)
   0x000003ff90752058 <+160>:     ld      %f10,336(%r5)
   0x000003ff9075205c <+164>:     ld      %f11,344(%r5)
   0x000003ff90752060 <+168>:     ld      %f12,352(%r5)
   0x000003ff90752064 <+172>:     ld      %f13,360(%r5)
   0x000003ff90752068 <+176>:     ld      %f14,368(%r5)
   0x000003ff9075206c <+180>:     ld      %f15,376(%r5)
   0x000003ff90752070 <+184>:     lam     %a2,%a15,192(%r5)
   0x000003ff90752074 <+188>:     lmg     %r0,%r15,56(%r5)
   0x000003ff9075207a <+194>:     br      %r14
End of assembler dump.

(gdb) i r
r0             0x0      0
r1             0x3ff8fe7de40    4396165881408
r2             0x0      0
r3             0x3ff8fe7e1c0    4396165882304
r4             0x3ff8fe7dfc0    4396165881792
r5             0x0      0
r6             0xffffffff88004880       18446744071696304256
r7             0x3ff880009e0    4396033247712
r8             0x27ff89000      10736930816
r9             0x3ff88001460    4396033250400
r10            0x1000   4096
r11            0x1261be0        19274720
r12            0x3ff88001e00    4396033252864
r13            0x14d0bc0        21826496
r14            0x1312ac8        19999432
r15            0x3ff8fe7dc80    4396165880960
pc             0x3ff9075202c    0x3ff9075202c <swapcontext+116>
cc             0x2      2