man-pages-3.50 is released

From: Michael Kerrisk (man-pages)
Date: Sat Mar 16 2013 - 12:38:17 EST


I've released man-pages-3.50 - man pages for Linux.

Tarball download:
Git repository:
Online changelog:

A short summary of the release is blogged at:

The current version of the pages is browsable at:

A few changes in this release that may be of interest to readers of
this list are given below.



==================== Changes in man-pages-3.50 ====================

New and rewritten pages

Michael Kerrisk
Rewrite page, adding much more detail

Changes to individual pages

Michael Kerrisk
Port access permission bits (ioperm()) are turned off in the child

Michael Kerrisk
Note that iopl() level of 3 is needed to access ports
Michael Kerrisk
'num' is *bits* not bytes!
Michael Kerrisk
Linux 2.6.8 lifted the port limit to 65,536
From: Stas Sergeev <stsp <at>>
Subject: [patch][rfc] Larger IO bitmap
Date: 2004-05-07 19:55:03 GMT
Michael Kerrisk
ioperm() operates on the calling *thread* (not process)
Michael Kerrisk
Clarify meaning of 'turn_on' argument
Plus form formatting fixes.
Michael Kerrisk
Clarify that default state of permission bits in child is off
Michael Kerrisk
NOTES: add mention of /proc/ioports
Michael Kerrisk
SEE ALSO: add outb(2)

Michael Kerrisk
CAP_SYS_RAWIO is required to *raise* the I/O privilege level
Michael Kerrisk
Clarify that the two least significant bits of 'level' are what matter
Michael Kerrisk
SEE ALSO: add outb(2)

Michael Kerrisk
Add version information for all (other) syscalls
Michael Kerrisk
Add perfmonctl(2)

Elie De Brauwer
Document write and document the ioctl interface of /dev/random
The update consists out of two parts:
- a minor thing which just documents what happens if a write to
/dev/(u)random is performed, which is used in the example
script but not explicitly mentioned.
- the other (biggest) part is the documentation of the ioctl()
interface which /dev/(u)random exposes. This ioctl() lives in
drivers/char/random.c and the primitives can be found in

One comment remains, there used to be an RNDGETPOOL ioctl() which
disappeared in v2.6.9. I found two patches on the net:

But as far as I can tell the first one got applied but the 2nd
one seems more correct. The result is that even today one can
still find traces of the RNDGETPOOL ioctl() in the header files.
Is this there for historical reasons or because it might break
userspace, even though using it will just give an EINVAL.

Jose Luis Domingo Lopez
Document 'rootfstype' option

Michael Kerrisk
Add various pieces under CAP_SYS_RAWIO
Info obtained by grepping the kernel source.
Michael Kerrisk
Add CAP_SYS_RESOURCE /proc/PID/oom_score_adj case

Andrey Vagin
Add a note about broadcast messages to multiple groups
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