LDP: Update original to LDP v3.79

[linuxjm/LDP_man-pages.git] / original / man2 / seteuid.2

diff --git a/original/man2/seteuid.2 b/original/man2/seteuid.2
index 40b2873..ee11a2f 100644 (file)
--- a/original/man2/seteuid.2
+++ b/original/man2/seteuid.2
@@ -1,5 +1,6 @@
 .\" Copyright (C) 2001 Andries Brouwer (aeb@cwi.nl)
 .\"
+.\" %%%LICENSE_START(VERBATIM)
 .\" Permission is granted to make and distribute verbatim copies of this
 .\" manual provided the copyright notice and this permission notice are
 .\" preserved on all copies.
@@ -19,12 +20,13 @@
 .\"
 .\" Formatted or processed versions of this manual, if unaccompanied by
 .\" the source, must acknowledge the copyright and authors of this work.
+.\" %%%LICENSE_END
 .\"
 .\" [should really be seteuid.3]
 .\" Modified, 27 May 2004, Michael Kerrisk <mtk.manpages@gmail.com>
 .\"     Added notes on capability requirements
 .\"
-.TH SETEUID 2 2009-10-17 "Linux" "Linux Programmer's Manual"
+.TH SETEUID 2 2014-09-21 "Linux" "Linux Programmer's Manual"
 .SH NAME
 seteuid, setegid \- set effective user or group ID
 .SH SYNOPSIS
@@ -62,14 +64,22 @@ with "group" instead of "user".
 .\" equals \-1, nothing is changed.
 .\" (This is an artifact of the implementation in glibc of seteuid()
 .\" using setresuid(2).)
-.SH "RETURN VALUE"
+.SH RETURN VALUE
 On success, zero is returned.
 On error, \-1 is returned, and
 .I errno
 is set appropriately.
+
+.IR Note :
+there are cases where
+.BR seteuid ()
+can fail even when the caller is UID 0;
+it is a grave security error to omit checking for a failure return from
+.BR seteuid ().
 .SH ERRORS
-.\" .TP
-.\" .B EINVAL
+.TP
+.B EINVAL
+The target user or group ID is not valid in this user namespace.
 .TP
 .B EPERM
 The calling process is not privileged (Linux: does not have the
@@ -86,7 +96,7 @@ and
 .IR egid )
 is not the real user (group) ID, the effective user (group) ID,
 or the saved set-user-ID (saved set-group-ID).
-.SH "CONFORMING TO"
+.SH CONFORMING TO
 4.3BSD, POSIX.1-2001.
 .SH NOTES
 Setting the effective user (group) ID to the
@@ -95,7 +105,7 @@ possible since Linux 1.1.37 (1.1.38).
 On an arbitrary system one should check
 .BR _POSIX_SAVED_IDS .
 .LP
-Under libc4, libc5 and glibc 2.0
+Under glibc 2.0
 .BI seteuid( euid )
 is equivalent to
 .BI setreuid(\-1, " euid" )
@@ -103,8 +113,13 @@ and hence may change the saved set-user-ID.
 Under glibc 2.1 and later it is equivalent to
 .BI setresuid(\-1, " euid" ", \-1)"
 and hence does not change the saved set-user-ID.
-Similar remarks hold for
-.BR setegid ().
+Analogous remarks hold for
+.BR setegid (),
+with the difference that the change in implementation from
+.BI setregid(\-1, " egid" )
+to
+.BI setresgid(\-1, " egid" ", \-1)"
+occurred in glibc 2.2 or 2.3 (depending on the hardware architecture).
 
 According to POSIX.1,
 .BR seteuid ()
@@ -114,10 +129,29 @@ need not permit
 .RI ( egid )
 to be the same value as the current effective user (group) ID,
 and some implementations do not permit this.
-.SH "SEE ALSO"
+.SS C library/kernel ABI differences
+On Linux,
+.BR seteuid ()
+and
+.BR setegid ()
+are implemented as library functions that call, respectively,
+.BR setreuid (2)
+and
+.BR setresgid (2).
+.SH SEE ALSO
 .BR geteuid (2),
 .BR setresuid (2),
 .BR setreuid (2),
 .BR setuid (2),
 .BR capabilities (7),
-.BR credentials (7)
+.BR credentials (7),
+.BR user_namespaces (7)
+.SH COLOPHON
+This page is part of release 3.79 of the Linux
+.I man-pages
+project.
+A description of the project,
+information about reporting bugs,
+and the latest version of this page,
+can be found at
+\%http://www.kernel.org/doc/man\-pages/.