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Bug 1852866

Summary:	valgrind doesn't recognize JMP rel32 with VEX prefix
Product:	Red Hat Developer Toolset	Reporter:	Mark Wielaard <mjw>
Component:	valgrind	Assignee:	Mark Wielaard <mjw>
Status:	CLOSED ERRATA	QA Contact:	Alexandra Petlanová Hájková <ahajkova>
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	DTS 10.0 RHEL 7	CC:	ahajkova, dsmith, jakub, jvanek, mcermak, mnewsome, ohudlick, tdeseyn
Target Milestone:	beta1
Target Release:	10.0
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:	devtoolset-10-valgrind-3.16.1-3	Doc Type:	No Doc Update
Doc Text:		Story Points:	---
Clone Of:
Clones:	1875331 (view as bug list)		Environment:
Last Closed:	2020-12-01 12:10:32 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:
Bug Blocks:	1875331, 1879761

Description Mark Wielaard 2020-07-01 13:41:14 UTC

This is necessary for running .net core programs under valgrind which generates a VEX prefixxed JMP rel32 instruction. A prelimenary patch (not accepted upstream yet) is in the valgrind bugzilla: https://bugs.kde.org/show_bug.cgi?id=422174

Note that even with this fix, .net core applications are valgrind "clean", but without this fix .net core just crashes under valgrind.

Comment 2 Mark Wielaard 2020-07-03 17:05:21 UTC

This is just to get dotnet to start up.
Using dotnet from dotnet-sdk-3.1 rpm.

Before the fix:
$ valgrind -q dotnet --version

Will crash with:

vex amd64->IR: unhandled instruction bytes: 0x48 0xE9 0x70 0xB3 0x41 0xA9 0x49 0xBA 0x88 0xCD
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

After the fix:
$ valgrind -q dotnet --version 2>/dev/null
3.1.103

There will still be warnings about Conditional jump or move depends on uninitialised value(s) and syscalls that use bad params.

Comment 8 errata-xmlrpc 2020-12-01 12:10:32 UTC

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory (new packages: devtoolset-10-valgrind), and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHEA-2020:5287