Bug 162294 - Reading DMI memory parts using mmap freeze the system
Summary: Reading DMI memory parts using mmap freeze the system
Status: Open
Alias: None
Product: Base System
Classification: Unclassified
Component: kern (show other bugs)
Version: 8.2-RELEASE
Hardware: Any Any
: Normal Affects Only Me
Assignee: freebsd-bugs (Nobody)
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2011-11-04 14:40 UTC by Sylvain Galliano
Modified: 2018-01-03 05:16 UTC (History)
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Description Sylvain Galliano 2011-11-04 14:40:08 UTC 
When several processes simultaneously read DMI datas (using dmidecode), the system freeze.

There is no issue in 8.1-RELEASE.

Fix: 

This issue seems to be related to mmap use in dmidecode.
In fact, if we change config.h in dmidecode port to disable mmap usage, all works fine. (In this case, dmidecode just open/read/close /dev/mem instead of mmap)
How-To-Repeat: Execute the following script:

#!/bin/sh

/usr/local/sbin/dmidecode -s system-serial-number &
/usr/local/sbin/dmidecode -s system-serial-number &
/usr/local/sbin/dmidecode -s system-serial-number &
/usr/local/sbin/dmidecode -s system-serial-number &
. hundreds of lines


after few execution (sometime the first one), the system freeze
Comment 1 Eitan Adler freebsd_committer freebsd_triage 2017-12-31 08:01:43 UTC 
For bugs matching the following criteria:

Status: In Progress Changed: (is less than) 2014-06-01

Reset to default assignee and clear in-progress tags.

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