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

dean.long at oracle.com dean.long at oracle.com
Thu Mar 22 20:59:57 UTC 2018


Gdb is not very useful for getting stack backtraces in generated JIT 
code, and it wouldn't know where to start because it apparently jumped 
to 0x000000000000dead.  I suggest trying -XX:+C1Breakpoint and then 
single-stepping through the generated code.

dl

On 3/22/18 9:32 AM, Leslie Zhai wrote:
> 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
>



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