148363 2007-07-30 16:50:32 +0000 vex amd64->IR: unhandled instruction bytes: 0x65 0x4C 0x8B 0x1C (mov %gs:0x10,%r11) 2014-05-28 00:46:51 +0000 1 1 6 Developer tools valgrind vex 3.2.3 Gentoo Packages Linux UNCONFIRMED NOR crash --- 253451 0 mihai.dontu jseward austinenglish 0 oldest_to_newest 538741 0 mihai.dontu 2007-07-30 16:50:32 +0000 Version: 3.2.3 (using KDE KDE 3.5.5) Installed from: Gentoo Packages Compiler: gcc-linux-x86_64 4.1.2 OS: Linux I have a small Win64 emu (much smaller/simpler than wine) which modifies the LDT. Since valgrind (3.2.3) does not support this trickery (amd64?), I wanted to add the support myself. However, more advanced things like: [...] vex amd64->IR: unhandled instruction bytes: 0x65 0x4C 0x8B 0x1C [...] Illegal opcode at address 0x406459C at 0x406459C: ??? by 0x0: ??? [...] stand in the way of true happiness :) $ gdb -c vgcore ./app $ (gdb) disas 0x000000000406459c 0x0000000004064600 Dump of assembler code from 0x406459c to 0x4064600: 0x000000000406459c: mov %gs:0x10,%r11 0x00000000040645a5: cmp %r11,%r10 It's in msvcrt.dll (v8.0), DllMain() I feel this is above my head :) 538773 1 mihai.dontu 2007-07-30 20:57:53 +0000 A small test program: #include <stdio.h> int main( void ) { __asm__ __volatile__ ( "movq %%gs:0x10,%%rax" : : ); return 0; } The code above should SIGSEGV because there's no ldt entry for %gs. 1451555 2 austinenglish 2014-05-28 00:46:51 +0000 austin@aw25 ~ $ gcc -o foo test.c austin@aw25 ~ $ valgrind ./foo ==18292== Memcheck, a memory error detector ==18292== Copyright (C) 2002-2013, and GNU GPL'd, by Julian Seward et al. ==18292== Using Valgrind-3.9.0 and LibVEX; rerun with -h for copyright info ==18292== Command: ./foo ==18292== ==18292== Conditional jump or move depends on uninitialised value(s) ==18292== at 0x40179E4: index (strchr.S:77) ==18292== by 0x400745D: expand_dynamic_string_token (dl-load.c:425) ==18292== by 0x400804F: _dl_map_object (dl-load.c:2302) ==18292== by 0x400138D: map_doit (rtld.c:626) ==18292== by 0x400E9A3: _dl_catch_error (dl-error.c:187) ==18292== by 0x4000B30: do_preload (rtld.c:815) ==18292== by 0x4004122: dl_main (rtld.c:1632) ==18292== by 0x401529B: _dl_sysdep_start (dl-sysdep.c:249) ==18292== by 0x4004A4C: _dl_start (rtld.c:331) ==18292== by 0x40011A7: ??? (in /lib64/ld-2.19.so) ==18292== vex amd64->IR: unhandled instruction bytes: 0x65 0x48 0x8B 0x4 0x25 0x10 0x0 0x0 vex amd64->IR: REX=1 REX.W=1 REX.R=0 REX.X=0 REX.B=0 vex amd64->IR: VEX=0 VEX.L=0 VEX.nVVVV=0x0 ESC=NONE vex amd64->IR: PFX.66=0 PFX.F2=0 PFX.F3=0 ==18292== valgrind: Unrecognised instruction at address 0x400501. ==18292== at 0x400501: main (in /home/austin/foo) ==18292== Your program just tried to execute an instruction that Valgrind ==18292== did not recognise. There are two possible reasons for this. ==18292== 1. Your program has a bug and erroneously jumped to a non-code ==18292== location. If you are running Memcheck and you just saw a ==18292== warning about a bad jump, it's probably your program's fault. ==18292== 2. The instruction is legitimate but Valgrind doesn't handle it, ==18292== i.e. it's Valgrind's fault. If you think this is the case or ==18292== you are not sure, please let us know and we'll try to fix it. ==18292== Either way, Valgrind will now raise a SIGILL signal which will ==18292== probably kill your program. ==18292== ==18292== Process terminating with default action of signal 4 (SIGILL) ==18292== Illegal opcode at address 0x400501 ==18292== at 0x400501: main (in /home/austin/foo) ==18292== ==18292== HEAP SUMMARY: ==18292== in use at exit: 0 bytes in 0 blocks ==18292== total heap usage: 0 allocs, 0 frees, 0 bytes allocated ==18292== ==18292== All heap blocks were freed -- no leaks are possible ==18292== ==18292== For counts of detected and suppressed errors, rerun with: -v ==18292== Use --track-origins=yes to see where uninitialised values come from ==18292== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0) Illegal instruction austin@aw25 ~ $ gcc -v Using built-in specs. COLLECT_GCC=/usr/x86_64-pc-linux-gnu/gcc-bin/4.8.2/gcc COLLECT_LTO_WRAPPER=/usr/libexec/gcc/x86_64-pc-linux-gnu/4.8.2/lto-wrapper Target: x86_64-pc-linux-gnu Configured with: /var/tmp/portage/sys-devel/gcc-4.8.2/work/gcc-4.8.2/configure --host=x86_64-pc-linux-gnu --build=x86_64-pc-linux-gnu --prefix=/usr --bindir=/usr/x86_64-pc-linux-gnu/gcc-bin/4.8.2 --includedir=/usr/lib/gcc/x86_64-pc-linux-gnu/4.8.2/include --datadir=/usr/share/gcc-data/x86_64-pc-linux-gnu/4.8.2 --mandir=/usr/share/gcc-data/x86_64-pc-linux-gnu/4.8.2/man --infodir=/usr/share/gcc-data/x86_64-pc-linux-gnu/4.8.2/info --with-gxx-include-dir=/usr/lib/gcc/x86_64-pc-linux-gnu/4.8.2/include/g++-v4 --with-python-dir=/share/gcc-data/x86_64-pc-linux-gnu/4.8.2/python --enable-languages=c,c++,java,go --enable-obsolete --enable-secureplt --disable-werror --with-system-zlib --disable-nls --enable-checking=release --with-bugurl=https://bugs.gentoo.org/ --with-pkgversion='Gentoo 4.8.2 p1.3r1, pie-0.5.8r1' --enable-libstdcxx-time --enable-shared --enable-threads=posix --enable-__cxa_atexit --enable-clocale=gnu --enable-multilib --with-multilib-list=m32,m64 --disable-altivec --disable-fixed-point --enable-targets=all --enable-libgomp --disable-libmudflap --disable-libssp --disable-libquadmath --enable-lto --without-cloog Thread model: posix gcc version 4.8.2 (Gentoo 4.8.2 p1.3r1, pie-0.5.8r1) austin@aw25 ~ $ valgrind --version valgrind-3.9.0