http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46515
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Last reconfirmed| |2010.11.18 16:17:40
CC| |jakub at gcc dot gnu.org
Ever Confirmed|0 |1
--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> 2010-11-18
16:17:40 UTC ---
This seems to be wrong unwind info for
_ZN10_Jv_Linker14wait_for_stateEPN4java4lang5ClassEi,
at least backtrace like:
#24 0x00007ffff5f73df2 in _Jv_Linker::resolve_pool_entry (klass=0x7fffeeb91618,
index=2, lazy=true) at ../../../libjava/link.cc:440
#25 0x00007ffff5f74158 in _Jv_Linker::ensure_class_linked
(klass=0x7fffeeb91618) at ../../../libjava/link.cc:1748
#26 0x00007ffff5f72a20 in _Jv_Linker::wait_for_state (klass=0x7fffeeb91618,
state=9) at ../../../libjava/link.cc:2076
#27 0x00007ffff5f737a8 in _Jv_Linker::get_interfaces (klass=0x7fffeeb91af8,
ifaces=0x7fffffffdbd0) at ../../../libjava/link.cc:777
#28 0x00007ffff5f74357 in _Jv_Linker::prepare_constant_time_tables
(klass=0x7fffeeb91af8) at ../../../libjava/link.cc:716
#29 0x00007ffff5f72b08 in _Jv_Linker::wait_for_state (klass=0x7fffeeb91af8,
state=7) at ../../../libjava/link.cc:2067
#30 0x0000000000000003 in ?? ()
#31 0x00007ffff5f733b6 in _Jv_Linker::link_symbol_table (klass=0x0) at
../../../libjava/link.cc:1308
#32 0x00007ffff5f72a30 in _Jv_Linker::wait_for_state (klass=0x7fffeeb913a8,
state=9) at ../../../libjava/link.cc:2078
#33 0x00007ffff5fa77e3 in java::lang::Class::initializeClass
(this=0x7fffeeb913a8) at ../../../libjava/java/lang/natClass.cc:720
suggests there (note the weird ra 0x00000003 in it). GDB doesn't crash on it,
but the libgcc unwinder does.
The code difference from yesterday in that routine is:
193f: 0f 84 79 fe ff ff je 17be
<_ZN10_Jv_Linker14wait_for_stateEPN4java4lang5ClassEi+0x1e>
1945: e8 00 00 00 00 callq 194a
<_ZN10_Jv_Linker14wait_for_stateEPN4java4lang5ClassEi+0x1aa>
1946: R_X86_64_PLT32 _Z20_Jv_GetCurrentJNIEnvv-0x4
- 194a: 48 83 c4 08 add $0x8,%rsp
- 194e: 48 89 d9 mov %rbx,%rcx
- 1951: 4c 89 ee mov %r13,%rsi
- 1954: 5b pop %rbx
- 1955: 5d pop %rbp
- 1956: 41 5c pop %r12
- 1958: 41 5d pop %r13
- 195a: 41 5e pop %r14
- 195c: 41 5f pop %r15
- 195e: 48 89 c2 mov %rax,%rdx
- 1961: bf 38 00 00 00 mov $0x38,%edi
- 1966: 31 c0 xor %eax,%eax
- 1968: e9 00 00 00 00 jmpq 196d
<_ZN10_Jv_Linker14wait_for_stateEPN4java4lang5ClassEi+0x1cd>
- 1969: R_X86_64_PLT32
_Z19_Jv_JVMTI_PostEvent10jvmtiEventPN4java4lang6ThreadEz-0x4
- 196d: 0f 1f 00 nopl (%rax)
+ 194a: 41 58 pop %r8
+ 194c: 48 89 d9 mov %rbx,%rcx
+ 194f: 4c 89 ee mov %r13,%rsi
+ 1952: 48 89 c2 mov %rax,%rdx
+ 1955: 5b pop %rbx
+ 1956: 5d pop %rbp
+ 1957: 41 5c pop %r12
+ 1959: 41 5d pop %r13
+ 195b: 41 5e pop %r14
+ 195d: 41 5f pop %r15
+ 195f: bf 38 00 00 00 mov $0x38,%edi
+ 1964: 31 c0 xor %eax,%eax
+ 1966: e9 00 00 00 00 jmpq 196b
<_ZN10_Jv_Linker14wait_for_stateEPN4java4lang5ClassEi+0x1cb>
+ 1967: R_X86_64_PLT32
_Z19_Jv_JVMTI_PostEvent10jvmtiEventPN4java4lang6ThreadEz-0x4
+ 196b: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1)
1970: 48 89 df mov %rbx,%rdi
1973: e8 00 00 00 00 callq 1978
<_ZN10_Jv_Linker14wait_for_stateEPN4java4lang5ClassEi+0x1d8>
1974: R_X86_64_PLT32
_ZN10_Jv_Linker28ensure_method_table_completeEPN4java4lang5ClassE-0x4
(i.e. replacement of addq $8, %rsp with popq %r8 and movq %rax, %rdx scheduled
elsewhere).
And unwind info difference is:
DW_CFA_advance_loc: 4 to 000017d0
DW_CFA_restore_state
- DW_CFA_advance_loc2: 382 to 0000194e
- DW_CFA_remember_state
+ DW_CFA_advance_loc2: 380 to 0000194c
DW_CFA_def_cfa_offset: 56
- DW_CFA_advance_loc: 7 to 00001955
+ DW_CFA_advance_loc: 10 to 00001956
+ DW_CFA_remember_state
DW_CFA_def_cfa_offset: 48
- DW_CFA_advance_loc: 1 to 00001956
+ DW_CFA_advance_loc: 1 to 00001957
DW_CFA_def_cfa_offset: 40
- DW_CFA_advance_loc: 2 to 00001958
+ DW_CFA_advance_loc: 2 to 00001959
DW_CFA_def_cfa_offset: 32
- DW_CFA_advance_loc: 2 to 0000195a
+ DW_CFA_advance_loc: 2 to 0000195b
DW_CFA_def_cfa_offset: 24
- DW_CFA_advance_loc: 2 to 0000195c
+ DW_CFA_advance_loc: 2 to 0000195d
DW_CFA_def_cfa_offset: 16
- DW_CFA_advance_loc: 2 to 0000195e
+ DW_CFA_advance_loc: 2 to 0000195f
DW_CFA_def_cfa_offset: 8
- DW_CFA_advance_loc: 18 to 00001970
+ DW_CFA_advance_loc: 17 to 00001970
DW_CFA_restore_state
Except for the expected DW_CFA_advance_loc changes, the important difference is
that before Richard's patch DW_CFA_remember_state preceeded
DW_CFA_def_cfa_offset 56 right after the add $8, %rsp insn, while with
Richard's patch DW_CFA_remember_state appears only after it. I'll preprocess
link.cc now and will see what is gong on at the RTL level...
