Bug 1769573

Summary:	gcc, libgcc need PAC unwinder to assure containers don't crash on newer systems.
Product:	Red Hat Enterprise Linux 7	Reporter:	Jeremy Linton (ARM) <jlinton>
Component:	gcc	Assignee:	Marek Polacek <mpolacek>
Status:	CLOSED ERRATA	QA Contact:	Alexandra Petlanová Hájková <ahajkova>
Severity:	low	Docs Contact:
Priority:	high
Version:	7.6-Alt	CC:	bgollahe, fweimer, jakub, law, mcermak, ohudlick, pvlasin, vmukhame
Target Milestone:	rc	Keywords:	ZStream
Target Release:	---
Hardware:	aarch64
OS:	Linux
Whiteboard:
Fixed In Version:	gcc-4.8.5-41.el7	Doc Type:	Bug Fix
Doc Text:	Cause: System libgcc couldn't parse the new DWARF operation introduced in the ARMv8.3-A Pointer Authentication Extension, supported in newer compilers. Consequence: Application could crash when DWARF unwinding. Fix: Extend libgcc so that it can parse the new DWARF operation used when return addresses haven been signed. Result: The application crash doesn't occur anymore.	Story Points:	---
Clone Of:
Clones:	1781152 (view as bug list)		Environment:
Last Closed:	2020-09-29 19:55:25 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:	1781152, 1782202

Description Jeremy Linton (ARM) 2019-11-06 21:32:12 UTC

Description of problem: ARMv8.3 pointer authentication is used to validate pointer validity before use. Its possible on newer hardware/OS's running older containers/static binaries/etc that the libgcc unwinder may not understand the high bit tweaking going on.

Here are the suggested patches to fix the problem:

https://gcc.gnu.org/viewcvs/gcc?view=revision&revision=244669
https://gcc.gnu.org/viewcvs/gcc?view=revision&revision=244673
https://gcc.gnu.org/viewcvs/gcc?view=revision&revision=244674

Comment 2 Marek Polacek 2019-11-12 16:15:09 UTC

libcc isn't part of gcc-libraries, recategorizing.

Comment 3 Marek Polacek 2019-11-12 16:15:45 UTC

(In reply to Marek Polacek from comment #2)
> libcc isn't part of gcc-libraries, recategorizing.

That should read "libgcc".

Comment 8 Marek Polacek 2019-12-07 17:39:04 UTC

gcc-4.8.5-41.el7 built

Comment 14 errata-xmlrpc 2020-09-29 19:55:25 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 (gcc bug fix and enhancement update), 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/RHBA-2020:3926