Bug 1527904 – glibc: PTHREAD_STACK_MIN is too small on x86-64

Bugzilla will be upgraded to version 5.0. The upgrade date is tentatively scheduled for 2 December 2018, pending final testing and feedback.

Bug 1527904 - glibc: PTHREAD_STACK_MIN is too small on x86-64

Summary:	glibc: PTHREAD_STACK_MIN is too small on x86-64

Status:	CLOSED ERRATA

Aliases:	None

Product:	Red Hat Enterprise Linux 7
Classification:	Red Hat
Component:	glibc (Show other bugs)
Sub Component:
Version:	7.5
Hardware:	Unspecified Unspecified

Priority	unspecified Severity unspecified
Target Milestone:	rc
Target Release:	---
Assigned To:	Carlos O'Donell
QA Contact:	Sergey Kolosov
Docs Contact:

URL:
Whiteboard:
Keywords:

Duplicates:	1538776 (view as bug list)
Depends On:	1527905
Blocks:
	Show dependency tree / graph

Reported:	2017-12-20 07:27 EST by Florian Weimer
Modified:	2018-04-10 10:04 EDT (History)
CC List:	9 users (show)

See Also:	1504969 1499012
Fixed In Version:	glibc-2.17-221.el7
Doc Type:	Bug Fix
Doc Text:	Applications with PTHREAD_STACK_MIN sized thread stacks may experience segmentation faults as those threads run out of stack space. Such applications have incorrectly expected PTHREAD_STACK_MIN to provide enough stack space to do more than just start the thread. Applications should add to PTHREAD_STACK_MIN the stack required for their own uses. As an intermediate solution to allow existing applications to continue to operate the C runtime has been adjusted to use less stack space for key functionality. Existing applications should now continue to operate with PTHREAD_STACK_MIN sized thread stacks.
Story Points:	---
Clone Of:	1527887
Environment:
Last Closed:	2018-04-10 10:04:32 EDT
Type:	Bug
Regression:	---
Mount Type:	---
Documentation:	---
CRM:
Verified Versions:
Category:	---
oVirt Team:	---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---

Attachments	(Terms of Use)
Add an attachment (proposed patch, testcase, etc.)

External Trackers
Tracker	ID	Priority	Status	Summary	Last Updated
Sourceware	22636	None	None	None	2017-12-20 07:40 EST
Red Hat Product Errata	RHSA-2018:0805	None	None	None	2018-04-10 10:04 EDT

Groups: None (edit)

Description Florian Weimer 2017-12-20 07:27:19 EST

Bug 1527887 shows that PTHREAD_STACK_MIN is really low on x86-64 (at 16384) and cannot accommodate both a signal handler frame, the libgcc unwinder, and an ld.so trampoline on AVX-512 (where the XSAVE area is around 2.5 KiB, and it is needed twice on the stack).

We should investigate ways how we can make for of those 16 KiB usable from applications.  At the very list, if the application requests a 16 KiB stack, it should get as much stack space as indicated, and not just 8 KiB.

Comment 1 Florian Weimer 2017-12-20 08:50:28 EST

This is a regression introduced by glibc-2.17-196.el7_4.2 in <https://access.redhat.com/errata/RHBA-2017:3296>.

Comment 7 Florian Weimer 2018-01-29 11:21:55 EST

*** Bug 1538776 has been marked as a duplicate of this bug. ***

Comment 11 errata-xmlrpc 2018-04-10 10:04:32 EDT

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, 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/RHSA-2018:0805

Note You need to log in before you can comment on or make changes to this bug.