[Bug libffi/52221] [libffi] r184021 needs to be fixed.

[jojelino at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52221

gee <jojelino at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |WAITING
         Resolution|FIXED                       |

--- Comment #4 from gee <jojelino at gmail dot com> 2012-02-13 17:02:18 UTC ---
(In reply to comment #3)
> Fixed.
No. it doesn't fixed. following debug session shows.

(gdb)
0x00fa0008 in ?? ()
(gdb) disp /5w $esp
6: x/5xw $esp
0x22fd7c:       0x696c5603      0x00e20e40      0x00a63fd0      0x00a63ff0
0x22fd8c:       0x00aa9848
(gdb) disp /w $ecx
7: x/xw $ecx  0xaa7e00: 0x00a6dc20
              ^^^^^^^^
                 this parameter
(gdb) ni
0x00fa000b in ?? ()
7: x/xw $ecx  0xaa7e00: 0x00a6dc20
6: x/5xw $esp
0x22fd7c:       0x696c5603      0x00e20e40      0x00a63fd0      0x00a63ff0
0x22fd8c:       0x00aa9848
(gdb) disp /i $eip
8: x/i $eip
=> 0xfa000b:    sub    $0xc,%esp
(gdb) ni
0x00fa000e in ?? ()
8: x/i $eip
=> 0xfa000e:    mov    %ecx,0x4(%esp)
7: x/xw $ecx  0xaa7e00: 0x00a6dc20
6: x/5xw $esp
0x22fd70:       0x00e20e40      0x00ace300      0x0022fda8      0x696c5603
0x22fd80:       0x00e20e40
(gdb)
0x00fa0012 in ?? ()
8: x/i $eip
=> 0xfa0012:    mov    %eax,(%esp)
7: x/xw $ecx  0xaa7e00: 0x00a6dc20
6: x/5xw $esp
0x22fd70:       0x00e20e40      0x00aa7e00      0x0022fda8      0x696c5603
0x22fd80:       0x00e20e40
(gdb)
0x00fa0015 in ?? ()
8: x/i $eip
=> 0xfa0015:    mov    $0x4,%eax
7: x/xw $ecx  0xaa7e00: 0x00a6dc20
6: x/5xw $esp
0x22fd70:       0x696c5603      0x00aa7e00      0x0022fda8      0x696c5603
0x22fd80:       0x00e20e40
(gdb)
0x00fa001a in ?? ()
8: x/i $eip
=> 0xfa001a:    lea    0x8(%esp),%ecx
7: x/xw $ecx  0xaa7e00: 0x00a6dc20
6: x/5xw $esp
0x22fd70:       0x696c5603      0x00aa7e00      0x0022fda8      0x696c5603
0x22fd80:       0x00e20e40
(gdb)
0x00fa001e in ?? ()
8: x/i $eip
=> 0xfa001e:    shr    $0x2,%eax
7: x/xw $ecx  0x22fd78: 0x0022fda8
6: x/5xw $esp
0x22fd70:       0x696c5603      0x00aa7e00      0x0022fda8      0x696c5603
0x22fd80:       0x00e20e40
(gdb)
0x00fa0021 in ?? ()
8: x/i $eip
=> 0xfa0021:    dec    %eax
7: x/xw $ecx  0x22fd78: 0x0022fda8
6: x/5xw $esp
0x22fd70:       0x696c5603      0x00aa7e00      0x0022fda8      0x696c5603
0x22fd80:       0x00e20e40
(gdb)
0x00fa0022 in ?? ()
8: x/i $eip
=> 0xfa0022:    je     0xfa002f
7: x/xw $ecx  0x22fd78: 0x0022fda8
6: x/5xw $esp
0x22fd70:       0x696c5603      0x00aa7e00      0x0022fda8      0x696c5603
0x22fd80:       0x00e20e40
(gdb)
0x00fa002f in ?? ()
8: x/i $eip
=> 0xfa002f:    mov    $0xfa0008,%eax
7: x/xw $ecx  0x22fd78: 0x0022fda8
6: x/5xw $esp
0x22fd70:       0x696c5603      0x00aa7e00      0x0022fda8      0x696c5603
0x22fd80:       0x00e20e40
(gdb)
0x00fa0034 in ?? ()
8: x/i $eip
=> 0xfa0034:    call   0x69ce18e0 <ffi_closure_raw_SYSV>
7: x/xw $ecx  0x22fd78: 0x0022fda8
6: x/5xw $esp
0x22fd70:       0x696c5603      0x00aa7e00      0x0022fda8      0x696c5603
0x22fd80:       0x00e20e40

Kai Tietz, could you explain why return address (0x696c5603) is at top of the
stack? (although it is not first argument for the method? i suspect that you
should have corrected this.)
top of the stack must be 0x00aa7e00, not 0x696c5603.

so it is turned out that thiscall trampoline code was invalid.