Re: [Qemu-devel] tcg/tcg.c:1892: tcg fatal error

[Blue Swirl]

On Sun, Apr 10, 2011 at 8:48 PM, Artyom Tarasenko <address@hidden> wrote:
> On Sun, Apr 10, 2011 at 4:44 PM, Blue Swirl <address@hidden> wrote:
>> On Sun, Apr 10, 2011 at 5:09 PM, Artyom Tarasenko <address@hidden> wrote:
>>> On Sun, Apr 10, 2011 at 3:24 PM, Aurelien Jarno <address@hidden> wrote:
>>>> On Sun, Apr 10, 2011 at 02:29:59PM +0200, Artyom Tarasenko wrote:
>>>>> Trying to boot some proprietary OS I get qemu-system-sparc64 crash with a
>>>>>
>>>>> tcg/tcg.c:1892: tcg fatal error
>>>>>
>>>>> error message.
>>>>>
>>>>> It looks like it can be a platform independent bug though, because
>>>>> when a '-singlestep' option IS present, qemu doesn't crash and seems
>>>>> to translate the code properly.
>>>>>
>>>>> (gdb) bt
>>>>> #0  0x00000032c2e327f5 in raise () from /lib64/libc.so.6
>>>>> #1  0x00000032c2e33fd5 in abort () from /lib64/libc.so.6
>>>>> #2  0x000000000051933d in tcg_reg_alloc_call (s=<value optimized out>,
>>>>> def=0x89d340, opc=INDEX_op_call, args=0x10acc98, dead_iargs=3) at
>>>>> qemu/tcg/tcg.c:1892
>>>>> #3  0x000000000051a557 in tcg_gen_code_common (s=0x10b8940,
>>>>> gen_code_buf=0x40338b60 "address@hidden 3\355I\211\256\220") at
>>>>> qemu/tcg/tcg.c:2099
>>>>> #4  tcg_gen_code (s=0x10b8940, gen_code_buf=0x40338b60 "address@hidden
>>>>> 3\355I\211\256\220") at qemu/tcg/tcg.c:2142
>>>>> #5  0x00000000004d38f1 in cpu_sparc_gen_code (env=0x10cce10,
>>>>> tb=0x7fffe91bc218, gen_code_size_ptr=0x7fffffffd9b4) at
>>>>> qemu/translate-all.c:93
>>>>> #6  0x00000000004d1fd7 in tb_gen_code (env=0x10cce10, pc=18868776,
>>>>> cs_base=18868780, flags=15, cflags=0) at qemu/exec.c:989
>>>>> #7  0x00000000004d4029 in tb_find_slow (env1=<value optimized out>) at
>>>>> qemu/cpu-exec.c:167
>>>>> #8  tb_find_fast (env1=<value optimized out>) at cpu-exec.c:194
>>>>> #9  cpu_sparc_exec (env1=<value optimized out>) at qemu/cpu-exec.c:556
>>>>> #10 0x0000000000408868 in tcg_cpu_exec () at qemu/cpus.c:1066
>>>>> #11 cpu_exec_all () at qemu/cpus.c:1102
>>>>> #12 0x000000000053c756 in main_loop (argc=<value optimized out>,
>>>>> argv=<value optimized out>, envp=<value optimized out>) at
>>>>> qemu/vl.c:1430
>>>>>
>>>>> I inspected ts->val_type causing the abort() case and it turned out to be 
>>>>> 0.
>>>>>
>>>>> The last lines of qemu.log (without -singlestep)
>>>>> IN:
>>>>> 0x00000000011fe9f0:  rdpr  %pstate, %g1
>>>>> 0x00000000011fe9f4:  wrpr  %g1, 2, %pstate
>>>>> --------------
>>>>> IN:
>>>>> 0x00000000011fe9f8:  ldub  [ %o0 ], %o1
>>>>> 0x00000000011fe9fc:  mov  %o1, %o2
>>>>> 0x00000000011fea00:  rdpr  %tick, %o3
>>>>> 0x00000000011fea04:  cmp  %o1, %o2
>>>>> 0x00000000011fea08:  be  %icc, 0x11fea00
>>>>> 0x00000000011fea0c:  ldub  [ %o0 ], %o2
>>>>>
>>>>> Search PC...
>>>>> Search PC...
>>>>> Search PC...
>>>>> Search PC...
>>>>> Search PC...
>>>>> Search PC...
>>>>> --------------
>>>>> IN:
>>>>> 0x00000000011fe9f8:  ldub  [ %o0 ], %o1
>>>>> 0x00000000011fe9fc:  mov  %o1, %o2
>>>>> 0x00000000011fea00:  rdpr  %tick, %o3
>>>>> 0x00000000011fea04:  cmp  %o1, %o2
>>>>> 0x00000000011fea08:  be  %icc, 0x11fea00
>>>>> 0x00000000011fea0c:  ldub  [ %o0 ], %o2
>>>>>
>>>>> 110521: Data Access MMU Miss (v=0068) pc=00000000011fe9f8
>>>>> npc=00000000011fe9fc SP=000000000180ae41
>>>>> pc: 00000000011fe9f8  npc: 00000000011fe9fc
>>>>>
>>>>> IN:
>>>>> 0x00000000011fea00:  rdpr  %tick, %o3
>>>>> 0x00000000011fea04:  cmp  %o1, %o2
>>>>> 0x00000000011fea08:  be  %icc, 0x11fea00
>>>>> 0x00000000011fea0c:  ldub  [ %o0 ], %o2
>>>>> --------------
>>>>> IN:
>>>>> 0x00000000011fea10:  brz,pn   %o2, 0x11fe9f8
>>>>> 0x00000000011fea14:  mov  %o2, %o4
>>>>> --------------
>>>>> IN:
>>>>> 0x00000000011fea18:  rdpr  %tick, %o5
>>>>> 0x00000000011fea1c:  cmp  %o2, %o4
>>>>> 0x00000000011fea20:  be  %icc, 0x11fea18
>>>>> 0x00000000011fea24:  ldub  [ %o0 ], %o4
>>>>> --------------
>>>>> IN:
>>>>> 0x00000000011fea28:  brz,pn   %o4, 0x11fe9f4
>>>>> 0x00000000011fea2c:  wrpr  %g0, %g1, %pstate
>>>>> <EOF>
>>>>>
>>>>> The crash is 100% reproducible and happens always on the same place,
>>>>> so it's probably a pure TCG issue, not related on getting the
>>>>> external/timer interrupts.
>>>>>
>>>>> Do you need any additional info?
>>>>>
>>>>
>>>> What would be interesting would be to get the corresponding TCG code
>>>> from qemu.log (-d op,op_opt).
>>>
>>>
>>> OP:
>>>  ---- 0x11fea28
>>>  ld_i64 tmp6,regwptr,$0x20
>>>  movi_i64 cond,$0x0
>>>  movi_i64 tmp8,$0x0
>>>  brcond_i64 tmp6,tmp8,ne,$0x0
>>>  movi_i64 cond,$0x1
>>>  set_label $0x0
>>>
>>>  ---- 0x11fea2c
>>>  movi_i64 tmp7,$0x0
>>>  xor_i64 tmp0,tmp7,g1
>>>  movi_i64 pc,$0x11fea2c
>>>  movi_i64 tmp8,$compute_psr
>>>  call tmp8,$0x0,$0
>>>  movi_i64 tmp8,$0x0
>>>  brcond_i64 cond,tmp8,eq,$0x1
>>>  movi_i64 npc,$0x11fe9f4
>>>  br $0x2
>>>  set_label $0x1
>>>  movi_i64 npc,$0x11fea30
>>>  set_label $0x2
>>>  movi_i64 tmp8,$wrpstate
>>>  call tmp8,$0x0,$0,tmp0
>>>  mov_i64 pc,npc
>>>  movi_i64 tmp8,$0x4
>>>  add_i64 npc,npc,tmp8
>>>  exit_tb $0x0
>>>
>>> OP after liveness analysis:
>>>  ---- 0x11fea28
>>>  ld_i64 tmp6,regwptr,$0x20
>>>  movi_i64 cond,$0x0
>>>  movi_i64 tmp8,$0x0
>>>  brcond_i64 tmp6,tmp8,ne,$0x0
>>>  movi_i64 cond,$0x1
>>>  set_label $0x0
>>>
>>>  ---- 0x11fea2c
>>>  nopn $0x2,$0x2
>>>  nopn $0x3,$0x68,$0x3
>>>  movi_i64 pc,$0x11fea2c
>>>  movi_i64 tmp8,$compute_psr
>>>  call tmp8,$0x0,$0
>>>  movi_i64 tmp8,$0x0
>>>  brcond_i64 cond,tmp8,eq,$0x1
>>>  movi_i64 npc,$0x11fe9f4
>>>  br $0x2
>>>  set_label $0x1
>>>  movi_i64 npc,$0x11fea30
>>>  set_label $0x2
>>>  movi_i64 tmp8,$wrpstate
>>>  call tmp8,$0x0,$0,tmp0
>>>  mov_i64 pc,npc
>>>  movi_i64 tmp8,$0x4
>>>  add_i64 npc,npc,tmp8
>>>  exit_tb $0x0
>>>  end
>>>
>>> Does it mean the last block is processed correctly and the crash
>>> happens on the next instruction which doesn't make it to the log?
>>> The next instruction would be a
>>>
>>> 0x00000000011fea30:  retl
>>>
>>> Since it's a branch instruction I guess this would also be a tcg block 
>>> boundary.
>>
>> Because abort() was called from tcg_reg_alloc_call, I'd say 'retl'
>> (synthetic op for 'jmpl %o8 + 8, %g0') was the problem.
>
> Any idea why? retl is not a rare instruction...

Sorry, calls are generated for helpers, so it's not 'jmpl' but the
call to wrpstate helper.