Bug 2029410 - glibc: Enabling MAP_32BIT using LD_PREFER_MAP_32BIT_EXEC variable doesn't work
Summary: glibc: Enabling MAP_32BIT using LD_PREFER_MAP_32BIT_EXEC variable doesn't work
Keywords:
Status: CLOSED ERRATA
Alias: None
Product: Red Hat Enterprise Linux 9
Classification: Red Hat
Component: glibc
Version: unspecified
Hardware: Unspecified
OS: Unspecified
low
low
Target Milestone: rc
: ---
Assignee: Florian Weimer
QA Contact: Sergey Kolosov
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2021-12-06 12:25 UTC by Martin Coufal
Modified: 2023-07-18 14:29 UTC (History)
8 users (show)

Fixed In Version: glibc-2.34-13.el9
Doc Type: No Doc Update
Doc Text:
Clone Of:
Environment:
Last Closed: 2022-05-17 15:48:51 UTC
Type: Bug
Target Upstream Version:
Embargoed:

Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Red Hat Issue Tracker RHELPLAN-104825 0 None None None 2021-12-06 12:26:55 UTC
Red Hat Product Errata RHBA-2022:3917 0 None None None 2022-05-17 15:49:17 UTC
Sourceware 28656 0 P2 NEW LD_PREFER_MAP_32BIT_EXEC no longer works due to binutils changes 2021-12-06 12:37:00 UTC

Description Martin Coufal 2021-12-06 12:25:51 UTC 
Description of problem:
Enabling mmap's MAP_32BIT does not work on rhel-9. See original bug for more details: bz1292018

How reproducible:
100%

Steps to Reproduce:
1. export LD_PREFER_MAP_32BIT_EXEC=1
2. strace -ttt -ff /bin/true |& grep MAP_32BIT


Additional info:
Works on rhel-7, rhel-8.
Comment 1 Florian Weimer 2021-12-06 12:32:47 UTC 
The first LOAD segment of system libraries is no longer executable, which disables MAP_32BIT in glibc. This is a result of a binutils change (likely defaulting to -z separate-code).
Comment 3 Florian Weimer 2021-12-10 22:02:02 UTC 
Upstream is going to remove this feature. We should backport the change to reduce confusion.
Comment 9 errata-xmlrpc 2022-05-17 15:48:51 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: glibc), 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-2022:3917
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