Re: [Valgrind-users] unrecognised instruction in 32bit dynamic linker

[John R. <jr...@bi...>]

> whenever i want to memcheck a 32bit program on my 64bit system i receive the following
> message:
> 
> vex x86->IR: unhandled instruction bytes: 0xC5 0xF9 0x6E 0x40
> ==16815== valgrind: Unrecognised instruction at address 0x44143d0.
> ==16815==    at 0x44143D0: _dl_sysdep_start (dl-sysdep.c:160)
> ==16815==    by 0x4404C47: _dl_start (rtld.c:336)
> ==16815==    by 0x4401096: ??? (in /lib32/ld-2.13.so)


$ gdb /lib32/ld-2.13.so
(gdb) disassem _dl_sysdep_start

and then perhaps do some matching on the low 12 bits (0xFFF) of the address:
0x44143D0 ==> any address ending in 0x3D0.


In 32-bit mode, hardware opcode 0xC5 is 'LDS' (Load Data Segment register),
which compiled software does not use.

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