Bug 455279

Summary:	vex amd64->IR: unhandled instruction bytes: 0x62 0xD2 0xFD 0x28 0x7C 0xC8 0x62 0xF2 0xFD 0x28
Product:	[Developer tools] valgrind	Reporter:	Feng Chen <fchen0000>
Component:	memcheck	Assignee:	Julian Seward <jseward>
Status:	RESOLVED DUPLICATE
Severity:	critical	CC:	gabravier, tom
Priority:	NOR
Version:	3.20 GIT
Target Milestone:	---
Platform:	RedHat Enterprise Linux
OS:	Linux
Latest Commit:		Version Fixed In:
Sentry Crash Report:

Description Feng Chen 2022-06-14 20:56:48 UTC

SUMMARY
==182758== Memcheck, a memory error detector
==182758== Copyright (C) 2002-2022, and GNU GPL'd, by Julian Seward et al.
==182758== Using Valgrind-3.20.0.GIT and LibVEX; rerun with -h for copyright info

vex amd64->IR: unhandled instruction bytes: 0x62 0xD2 0xFD 0x28 0x7C 0xC8 0x62 0xF2 0xFD 0x28
vex amd64->IR:   REX=0 REX.W=0 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
==182758== valgrind: Unrecognised instruction at address 0x5280f9.


STEPS TO REPRODUCE
1. my specific code compiled on this platform failed to be traced by valgrind
2. The machine is Red Hat Enterprise Linux Server release 6.10 (Santiago)
3. The compiler is mix of gcc9.0 (with dev-toolset9) and icc-2019


SOFTWARE/OS VERSIONS
Linux/KDE Plasma: 
Red Hat Enterprise Linux Server release 6.10 (Santiago)

Comment 1 Tom Hughes 2022-06-14 21:26:14 UTC

Well 0x62 is a BOUND instruction, or it would be in 32 bit mode, but it's not valid in 64 bit mode.

Did you get any warnings from valgrind before that about referencing undefined values?

Comment 2 Tom Hughes 2022-06-14 21:29:24 UTC

Ah it's an EVEX prefix now but the opcode map in the Intel manual helpfully doesn't mention that...

There is no AVX512 support in valgrind currently so you can't run code that is compiled to use AVX512 instructions.

Comment 3 Tom Hughes 2022-06-14 21:30:18 UTC


*** This bug has been marked as a duplicate of bug 383010 ***