https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65612
H.J. Lu <hjl.tools at gmail dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Last reconfirmed| |2015-03-29
CC| |tmsriram at google dot com
Ever confirmed|0 |1
--- Comment #2 from H.J. Lu <hjl.tools at gmail dot com> ---
(gdb) bt
#0 0x0000000000000706 in ?? ()
#1 0x0000555555554b69 in foo ()
at /export/gnu/import/git/gcc/gcc/testsuite/g++.dg/ext/mv1.C:32
#2 0x00007ffff7de76b8 in _dl_relocate_object ()
from /lib64/ld-linux-x86-64.so.2
#3 0x00007ffff7ddea4a in dl_main () from /lib64/ld-linux-x86-64.so.2
#4 0x00007ffff7df28d5 in _dl_sysdep_start () from /lib64/ld-linux-x86-64.so.2
#5 0x00007ffff7ddfce1 in _dl_start () from /lib64/ld-linux-x86-64.so.2
#6 0x00007ffff7ddbcd8 in _start () from /lib64/ld-linux-x86-64.so.2
#7 0x0000000000000001 in ?? ()
#8 0x00007fffffffe18d in ?? ()
#9 0x0000000000000000 in ?? ()
(gdb) f 1
#1 0x0000555555554b69 in foo ()
at /export/gnu/import/git/gcc/gcc/testsuite/g++.dg/ext/mv1.C:32
32 int (*p)() = &foo;
(gdb) disass
Dump of assembler code for function _Z3foov.resolver(void):
0x0000555555554b60 <+0>: sub $0x8,%rsp
0x0000555555554b64 <+4>: callq 0x555555554700 <__cpu_indicator_init@plt>
=> 0x0000555555554b69 <+9>: mov 0x200740(%rip),%rsi #
0x5555557552b0
0x0000555555554b70 <+16>: mov 0xc(%rsi),%edx
0x0000555555554b73 <+19>: mov %edx,%eax
0x0000555555554b75 <+21>: mov %edx,%ecx
0x0000555555554b77 <+23>: and $0x400,%eax
0x0000555555554b7c <+28>: and $0x40,%ecx
0x0000555555554b7f <+31>: cmp %ecx,%eax
0x0000555555554b81 <+33>: cmovg %ecx,%eax
0x0000555555554b84 <+36>: test %eax,%eax
0x0000555555554b86 <+38>: jle 0x555555554b98
<_Z3foov.resolver(void)+56>
0x0000555555554b88 <+40>: lea -0xbf(%rip),%rax # 0x555555554ad0
<_Z3foov.avx2_ssse3>
0x0000555555554b8f <+47>: add $0x8,%rsp
0x0000555555554b93 <+51>: retq
0x0000555555554b94 <+52>: nopl 0x0(%rax)
0x0000555555554b98 <+56>: cmpl $0x8,0x8(%rsi)
0x0000555555554b9c <+60>: jne 0x555555554bb0
<_Z3foov.resolver(void)+80---Type <return> to continue, or q <return> to
quit---q
Quit
(gdb) disass 0x0000555555554700,+16
Dump of assembler code from 0x555555554700 to 0x555555554710:
0x0000555555554700 <__cpu_indicator_init@plt+0>: jmpq *0x200be2(%rip)
# 0x5555557552e8 <__cpu_indicator_i...@got.plt>
0x0000555555554706 <__cpu_indicator_init@plt+6>: pushq $0x2
0x000055555555470b <__cpu_indicator_init@plt+11>: jmpq 0x5555555546c0
End of assembler dump.
(gdb)
We can't call __cpu_indicator_init in PIE while PIE is being relocated.
Its .got.plt section hasn't been updated. It works for non-PIE since
no update on .got.plt section is required. Can we move __cpu_indicator_init
to main executable?
