How to use gdb to debug C1 compiler's internal error?

Leslie Zhai lesliezhai at llvm.org.cn
Thu Mar 22 16:32:13 UTC 2018


Hi HotSpot compiler developers,

I am new to HotSpot C1 compiler, and I am trying to implement a new 
greedy register allocation skeleton for academy research, but might 
wrongly modified some code, for example, 
`Runtime1::generate_handle_exception` in 
jdk/src/hotspot/cpu/x86/c1_Runtime1_x86.cpp, then `install_code` failed 
to work and thrown such internal error:

...

[Stub Code]
   0x00007fffe13752a0: mov    $0x0,%rbx          ;   {no_reloc}
   0x00007fffe13752aa: jmpq   0x00007fffe13752aa  ; {runtime_call}
[Exception Handler]
   0x00007fffe13752af: jmpq   0x00007fffe1004ee0  ; {runtime_call}
[Deopt Handler Code]
   0x00007fffe13752b4: callq  0x00007fffe13752b9
   0x00007fffe13752b9: subq   $0x5,(%rsp)
   0x00007fffe13752be: jmpq   0x00007fffe11072e0  ; {runtime_call}
   0x00007fffe13752c3: hlt
   0x00007fffe13752c4: hlt
   0x00007fffe13752c5: hlt
   0x00007fffe13752c6: hlt
   0x00007fffe13752c7: hlt
Decoding compiled method 0x00007fffe136d310:
Code:
[Entry Point]
   # {method} {0x00007fffe015e0e0} 'fillInStackTrace' 
'(I)Ljava/lang/Throwable;' in 'java/lang/Throwable'
   # this:     rsi:rsi   = 'java/lang/Throwable'
   # parm0:    rdx       = int
   #           [sp+0x50]  (sp of caller)
   0x00007fffe136d4a0: mov    0x8(%rsi),%r10d
   0x00007fffe136d4a4: shl    $0x3,%r10
   0x00007fffe136d4a8: cmp    %r10,%rax
   0x00007fffe136d4ab: je     0x00007fffe136d4b8
   0x00007fffe136d4b1: jmpq   0x00007fffe1105c40  ; {runtime_call}
   0x00007fffe136d4b6: nop
   0x00007fffe136d4b7: nop
[Verified Entry Point]
   0x00007fffe136d4b8: mov    %eax,-0x16000(%rsp)
   0x00007fffe136d4bf: push   %rbp
   0x00007fffe136d4c0: mov    %rsp,%rbp
   0x00007fffe136d4c3: sub    $0x40,%rsp
   0x00007fffe136d4c7: mov    %rsp,%rax
   0x00007fffe136d4ca: and    $0xfffffffffffffff0,%rax
   0x00007fffe136d4ce: cmp    %rsp,%rax
   0x00007fffe136d4d1: je     0x00007fffe136d54e
   0x00007fffe136d4d7: mov    %rsp,-0x28(%rsp)
   0x00007fffe136d4dc: sub    $0x80,%rsp
   0x00007fffe136d4e3: mov    %rax,0x78(%rsp)
   0x00007fffe136d4e8: mov    %rcx,0x70(%rsp)
   0x00007fffe136d4ed: mov    %rdx,0x68(%rsp)
   0x00007fffe136d4f2: mov    %rbx,0x60(%rsp)
   0x00007fffe136d4f7: mov    %rbp,0x50(%rsp)
   0x00007fffe136d4fc: mov    %rsi,0x48(%rsp)
   0x00007fffe136d501: mov    %rdi,0x40(%rsp)
   0x00007fffe136d506: mov    %r8,0x38(%rsp)
   0x00007fffe136d50b: mov    %r9,0x30(%rsp)
   0x00007fffe136d510: mov    %r10,0x28(%rsp)
   0x00007fffe136d515: mov    %r11,0x20(%rsp)
   0x00007fffe136d51a: mov    %r12,0x18(%rsp)
   0x00007fffe136d51f: mov    %r13,0x10(%rsp)
   0x00007fffe136d524: mov    %r14,0x8(%rsp)
   0x00007fffe136d529: mov    %r15,(%rsp)
   0x00007fffe136d52d: mov    $0x7ffff6dbea09,%rdi  ; {external_word}
   0x00007fffe136d537: mov    $0x7fffe136d4d7,%rsi  ; {internal_word}
   0x00007fffe136d541: mov    %rsp,%rdx
   0x00007fffe136d544: and    $0xfffffffffffffff0,%rsp
   0x00007fffe136d548: callq  0x00007ffff68211ee  ; {runtime_call}
   0x00007fffe136d54d: hlt
   ;; move 1 -> 2
   ;; move 0 -> 1
   0x00007fffe136d54e: mov    %rsi,(%rsp)
   0x00007fffe136d552: cmp    $0x0,%rsi
   0x00007fffe136d556: lea    (%rsp),%rsi
   0x00007fffe136d55a: cmove  (%rsp),%rsi        ; OopMap{[0]=Oop off=191}
   0x00007fffe136d55f: mov    $0x7fffe136d55f,%r10  ; {section_word}
   0x00007fffe136d569: mov    %r10,0x208(%r15)
   0x00007fffe136d570: mov    %rsp,0x200(%r15)
   0x00007fffe136d577: cmpb   $0x0,0x1602de2c(%rip)        # 
0x00007ffff739b3aa
                                                 ; {external_word}
   0x00007fffe136d57e: je     0x00007fffe136d5b8
   0x00007fffe136d584: push   %rsi
   0x00007fffe136d585: push   %rdx
   0x00007fffe136d586: mov    $0x7fffe015e0e0,%rsi  ; {metadata({method} 
{0x00007fffe015e0e0} 'fillInStackTrace' '(I)Ljava/lang/Throwable;' in 
'java/lang/Throwable')}
   0x00007fffe136d590: mov    %r15,%rdi
   0x00007fffe136d593: test   $0xf,%esp
   0x00007fffe136d599: je     0x00007fffe136d5b1
   0x00007fffe136d59f: sub    $0x8,%rsp
   0x00007fffe136d5a3: callq  0x00007ffff69c48ae  ; {runtime_call}
   0x00007fffe136d5a8: add    $0x8,%rsp
   0x00007fffe136d5ac: jmpq   0x00007fffe136d5b6
   0x00007fffe136d5b1: callq  0x00007ffff69c48ae  ; {runtime_call}
   0x00007fffe136d5b6: pop    %rdx
   0x00007fffe136d5b7: pop    %rsi
   0x00007fffe136d5b8: lea    0x220(%r15),%rdi
   0x00007fffe136d5bf: movl   $0x4,0x298(%r15)
   0x00007fffe136d5ca: callq  0x00007ffff4f55fef  ; {runtime_call}
   0x00007fffe136d5cf: vzeroupper
   0x00007fffe136d5d2: movl   $0x5,0x298(%r15)
   0x00007fffe136d5dd: mov    %r15d,%ecx
   0x00007fffe136d5e0: shr    $0x4,%ecx
   0x00007fffe136d5e3: and    $0xffc,%ecx
   0x00007fffe136d5e9: mov    $0x7ffff7ff3000,%r10  ; {external_word}
   0x00007fffe136d5f3: mov    %ecx,(%r10,%rcx,1)
   0x00007fffe136d5f7: cmpl   $0x0,0x1603f89f(%rip)        # 
0x00007ffff73acea0
                                                 ; {external_word}
   0x00007fffe136d601: jne    0x00007fffe136d615
   0x00007fffe136d607: cmpl   $0x0,0x30(%r15)
   0x00007fffe136d60f: je     0x00007fffe136d636
   0x00007fffe136d615: mov    %rax,-0x8(%rbp)
   0x00007fffe136d619: mov    %r15,%rdi
   0x00007fffe136d61c: mov    %rsp,%r12
   0x00007fffe136d61f: sub    $0x0,%rsp
   0x00007fffe136d623: and    $0xfffffffffffffff0,%rsp
   0x00007fffe136d627: callq  0x00007ffff6a691da  ; {runtime_call}
   0x00007fffe136d62c: mov    %r12,%rsp
   0x00007fffe136d62f: xor    %r12,%r12
   0x00007fffe136d632: mov    -0x8(%rbp),%rax
   0x00007fffe136d636: movl   $0x8,0x298(%r15)
   0x00007fffe136d641: cmpl   $0x1,0x2c4(%r15)
   0x00007fffe136d64c: je     0x00007fffe136d6e8
   0x00007fffe136d652: cmpb   $0x0,0x1602dd51(%rip)        # 
0x00007ffff739b3aa
                                                 ; {external_word}
   0x00007fffe136d659: je     0x00007fffe136d697
   0x00007fffe136d65f: mov    %rax,-0x8(%rbp)
   0x00007fffe136d663: mov    $0x7fffe015e0e0,%rsi  ; {metadata({method} 
{0x00007fffe015e0e0} 'fillInStackTrace' '(I)Ljava/lang/Throwable;' in 
'java/lang/Throwable')}
   0x00007fffe136d66d: mov    %r15,%rdi
   0x00007fffe136d670: test   $0xf,%esp
   0x00007fffe136d676: je     0x00007fffe136d68e
   0x00007fffe136d67c: sub    $0x8,%rsp
   0x00007fffe136d680: callq  0x00007ffff69c4ab8  ; {runtime_call}
   0x00007fffe136d685: add    $0x8,%rsp
   0x00007fffe136d689: jmpq   0x00007fffe136d693
   0x00007fffe136d68e: callq  0x00007ffff69c4ab8  ; {runtime_call}
   0x00007fffe136d693: mov    -0x8(%rbp),%rax
   0x00007fffe136d697: mov    $0x0,%r10
   0x00007fffe136d6a1: mov    %r10,0x200(%r15)
   0x00007fffe136d6a8: mov    $0x0,%r10
   0x00007fffe136d6b2: mov    %r10,0x208(%r15)
   0x00007fffe136d6b9: test   %rax,%rax
   0x00007fffe136d6bc: je     0x00007fffe136d6c5
   0x00007fffe136d6c2: mov    (%rax),%rax
   0x00007fffe136d6c5: mov    0x38(%r15),%rcx
   0x00007fffe136d6c9: movl   $0x0,0x108(%rcx)
   0x00007fffe136d6d3: leaveq
   0x00007fffe136d6d4: cmpq   $0x0,0x8(%r15)
   0x00007fffe136d6dc: jne    0x00007fffe136d6e3
   0x00007fffe136d6e2: retq
   0x00007fffe136d6e3: jmpq   Stub::forward exception  ; {runtime_call}
   0x00007fffe136d6e8: mov    %rax,-0x8(%rbp)
   0x00007fffe136d6ec: mov    %rsp,%r12
   0x00007fffe136d6ef: sub    $0x0,%rsp
   0x00007fffe136d6f3: and    $0xfffffffffffffff0,%rsp
   0x00007fffe136d6f7: callq  0x00007ffff69c8b64  ; {runtime_call}
   0x00007fffe136d6fc: mov    %r12,%rsp
   0x00007fffe136d6ff: xor    %r12,%r12
   0x00007fffe136d702: mov    -0x8(%rbp),%rax
   0x00007fffe136d706: jmpq   0x00007fffe136d652
   0x00007fffe136d70b: hlt
   0x00007fffe136d70c: hlt
   0x00007fffe136d70d: hlt
   0x00007fffe136d70e: hlt
   0x00007fffe136d70f: hlt

#
# A fatal error has been detected by the Java Runtime Environment:
#
#  SIGSEGV (0xb) at pc=0x000000000000dead, pid=2174, tid=0x00007ffff7fc8700
#
# JRE version: OpenJDK Runtime Environment (8.0) (build 
1.8.0-internal-debug-xiangzhai_2018_03_19_20_27-b00)
# Java VM: OpenJDK 64-Bit Server VM (25.71-b00-debug compiled mode 
linux-amd64 compressed oops)
# Problematic frame:
# C  0x000000000000dead
#
# Core dump written. Default location: 
/data/project/openjdk/jdk8u/hotspot/test/compiler/5057225/core or core.2174
#
# An error report file with more information is saved as:
# 
/data/project/openjdk/jdk8u/hotspot/test/compiler/5057225/hs_err_pid2174.log

Compiled method (c1)   21870  156   !   3 
java.lang.ClassLoader::loadClass (122 bytes)
  total in heap  [0x00007fffe12bcc90,0x00007fffe12beee0] = 8784
  relocation     [0x00007fffe12bcdc0,0x00007fffe12bcfb8] = 504
  main code      [0x00007fffe12bcfc0,0x00007fffe12be2c0] = 4864
  stub code      [0x00007fffe12be2c0,0x00007fffe12be460] = 416
  metadata       [0x00007fffe12be460,0x00007fffe12be4a0] = 64
  scopes data    [0x00007fffe12be4a0,0x00007fffe12be848] = 936
  scopes pcs     [0x00007fffe12be848,0x00007fffe12becd8] = 1168
  dependencies   [0x00007fffe12becd8,0x00007fffe12bece0] = 8
  handler table  [0x00007fffe12bece0,0x00007fffe12beea8] = 456
  nul chk table  [0x00007fffe12beea8,0x00007fffe12beee0] = 56
Compiled method (c1)   21871  156   !   3 
java.lang.ClassLoader::loadClass (122 bytes)
  total in heap  [0x00007fffe12bcc90,0x00007fffe12beee0] = 8784
  relocation     [0x00007fffe12bcdc0,0x00007fffe12bcfb8] = 504
  main code      [0x00007fffe12bcfc0,0x00007fffe12be2c0] = 4864
  stub code      [0x00007fffe12be2c0,0x00007fffe12be460] = 416
  metadata       [0x00007fffe12be460,0x00007fffe12be4a0] = 64
  scopes data    [0x00007fffe12be4a0,0x00007fffe12be848] = 936
  scopes pcs     [0x00007fffe12be848,0x00007fffe12becd8] = 1168
  dependencies   [0x00007fffe12becd8,0x00007fffe12bece0] = 8
  handler table  [0x00007fffe12bece0,0x00007fffe12beea8] = 456
  nul chk table  [0x00007fffe12beea8,0x00007fffe12beee0] = 56
#
# If you would like to submit a bug report, please visit:
#   http://bugreport.java.com/bugreport/crash.jsp
#
Current thread is 140737353910016
Dumping core ...

[Switching to Thread 0x7ffff7fc8700 (LWP 2178)]
__GI_raise (sig=sig at entry=6) at ../sysdeps/unix/sysv/linux/raise.c:51
51      }
(gdb) bt
#0  __GI_raise (sig=sig at entry=6) at ../sysdeps/unix/sysv/linux/raise.c:51
#1  0x00007ffff740c4da in __GI_abort () at abort.c:89
#2  0x00007ffff6905d0b in os::abort (dump_core=true)
     at 
/data/project/openjdk/jdk8u/hotspot/src/os/linux/vm/os_linux.cpp:1515
#3  0x00007ffff6ac75fc in VMError::report_and_die (this=0x7ffff7fc6400)
     at 
/data/project/openjdk/jdk8u/hotspot/src/share/vm/utilities/vmError.cpp:1060
#4  0x00007ffff6ac7d29 in crash_handler (sig=11, info=0x7ffff7fc6630, 
ucVoid=0x7ffff7fc6500)
     at 
/data/project/openjdk/jdk8u/hotspot/src/os/linux/vm/vmError_linux.cpp:106
#5  <signal handler called>
#6  0x00007ffff690071a in os::print_hex_dump (st=0x7ffff7fc6c30,
     start=0xde8d <error: Cannot access memory at address 0xde8d>,
     end=0xdecd <error: Cannot access memory at address 0xdecd>, unitsize=1)
     at /data/project/openjdk/jdk8u/hotspot/src/share/vm/runtime/os.cpp:802
#7  0x00007ffff691328e in os::print_context (st=0x7ffff7fc6c30, 
context=0x7ffff7fc6f00)
     at 
/data/project/openjdk/jdk8u/hotspot/src/os_cpu/linux_x86/vm/os_linux_x86.cpp:823
#8  0x00007ffff6ac5adb in VMError::report (this=0x7ffff7fc6d50, 
st=0x7ffff7fc6c30)
     at 
/data/project/openjdk/jdk8u/hotspot/src/share/vm/utilities/vmError.cpp:534
#9  0x00007ffff6ac70cc in VMError::report_and_die (this=0x7ffff7fc6d50)
     at 
/data/project/openjdk/jdk8u/hotspot/src/share/vm/utilities/vmError.cpp:971
#10 0x00007ffff6912bde in JVM_handle_linux_signal (sig=11, 
info=0x7ffff7fc7030, ucVoid=0x7ffff7fc6f00,
     abort_if_unrecognized=1)
     at 
/data/project/openjdk/jdk8u/hotspot/src/os_cpu/linux_x86/vm/os_linux_x86.cpp:541
#11 0x00007ffff690be1d in signalHandler (sig=11, info=0x7ffff7fc7030, 
uc=0x7ffff7fc6f00)
     at 
/data/project/openjdk/jdk8u/hotspot/src/os/linux/vm/os_linux.cpp:4435
#12 <signal handler called>
...

So backtrace or set breakpoint might be helpful for debugging compiling 
thread, but doesn't work for running thread? I am reading Analyzing and 
Debugging the HotSpot VM at the OS Level[1] please give me some advice, 
thanks a lot!

[1] http://www.progdoc.de/papers/JavaOne2014/javaone2014_con3138.html

-- 
Regards,
Leslie Zhai





More information about the hotspot-compiler-dev mailing list