.\" Hey Emacs! This file is -*- nroff -*- source.
.\"
.\" Copyright (C) 1998 Andries Brouwer (aeb@cwi.nl)
.\" and Copyright (C) 2002 Michael Kerrisk <mtk.manpages@gmail.com>
.\" and Copyright Guillem Jover <guillem@hadrons.org>
.\"
.\" 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.
.\"
.\" Permission is granted to copy and distribute modified versions of this
.\" manual under the conditions for verbatim copying, provided that the
.\" entire resulting derived work is distributed under the terms of a
.\" permission notice identical to this one.
.\"
.\" Since the Linux kernel and libraries are constantly changing, this
.\" manual page may be incorrect or out-of-date.  The author(s) assume no
.\" responsibility for errors or omissions, or for damages resulting from
.\" the use of the information contained herein.  The author(s) may not
.\" have taken the same level of care in the production of this manual,
.\" which is licensed free of charge, as they might when working
.\" professionally.
.\"
.\" Formatted or processed versions of this manual, if unaccompanied by
.\" the source, must acknowledge the copyright and authors of this work.
.\"
.\" Modified Thu Nov 11 04:19:42 MET 1999, aeb: added PR_GET_PDEATHSIG
.\" Modified 27 Jun 02, Michael Kerrisk
.\" 	Added PR_SET_DUMPABLE, PR_GET_DUMPABLE,
.\"	PR_SET_KEEPCAPS, PR_GET_KEEPCAPS
.\" Modified 2006-08-30 Guillem Jover <guillem@hadrons.org>
.\"	Updated Linux versions where the options where introduced.
.\"	Added PR_SET_TIMING, PR_GET_TIMING, PR_SET_NAME, PR_GET_NAME,
.\"	PR_SET_UNALIGN, PR_GET_UNALIGN, PR_SET_FPEMU, PR_GET_FPEMU,
.\"	PR_SET_FPEXC, PR_GET_FPEXC
.\" 2008-04-29 Serge Hallyn, Document PR_CAPBSET_READ and PR_CAPBSET_DROP
.\" 2008-06-13 Erik Bosman, <ejbosman@cs.vu.nl>
.\"     Document PR_GET_TSC and PR_SET_TSC.
.\" 2008-06-15 mtk, Document PR_SET_SECCOMP, PR_GET_SECCOMP
.\"
.\" Japanese Version Copyright (c) 1998-1999 HANATAKA Shinya
.\"         all rights reserved.
.\" Translated 1999-04-03, HANATAKA Shinya <hanataka@abyss.rim.or.jp>
.\" Updated 2002-12-20, Kentaro Shirakata <argrath@ub32.org>
.\" Updated 2005-09-06, Akihiro MOTOKI <amotoki@dd.iij4u.or.jp>
.\" Updated 2005-10-07, Akihiro MOTOKI
.\" Updated 2007-01-08, Akihiro MOTOKI, LDP v2.43
.\" Updated 2007-10-12, Akihiro MOTOKI, LDP v2.66
.\" Updated 2008-08-12, Akihiro MOTOKI, LDP v3.05
.\"
.\"WORD:	capability	ѥӥƥ
.\"WORD:	keep capabilities	ѥӥƥݻ
.\"
.TH PRCTL 2 2008-07-16 "Linux" "Linux Programmer's Manual"
.SH ̾
prctl \- ץԤʤ
.SH 
.nf
.B #include <sys/prctl.h>
.sp
.BI "int prctl(int " option ", unsigned long " arg2 ", unsigned long " arg3 ,
.BI "          unsigned long " arg4 ", unsigned long " arg5 );
.fi
.SH 
.BR prctl ()
ưϺǽΰˤäƷꤵ (ͤ
\fI<linux/prctl.h>\fP Ƥ)
ĤΰϺǽΰˤäѲ롣
ܤΰȤưʲΤΤǤ:
.TP
.BR PR_CAPBSET_READ " (Linux 2.6.25 ʹ)"
ǻꤵ줿ѥӥƥƤӽФåɤΥѥӥƥ
Хǥ󥰥å (capability bounding set) ˴ޤޤƤ硢
(ؿ֤ͤȤ) 1 ֤Ǥʤ 0 ֤
(ѥӥƥ
.I <linux/capability.h>
Ƥ)
ѥӥƥХǥ󥰥åȤϡ
.BR execve (2)
ƤӽФݤˡեε (permitted) ѥӥƥ
ΥץǤ륱ѥӥƥؼΤǤ롣

.I arg2
˻ꤵ줿ѥӥƥͭǤʤ硢
ƤӽФϥ顼
.B EINVAL
ǼԤ롣
.TP
.BR PR_CAPBSET_DROP " (Linux 2.6.25 ʹ)"
ƤӽФåɤѥӥƥ
.B CAP_SETPCAP
äƤ硢
ƤӽФåɤΥѥӥƥХǥ󥰥åȤ
.I arg2
ǻꤵ줿ѥӥƥ򳰤
ƤӽФåɤλҥץѹΥХǥ󥰥åȤ
Ѿ롣

ƤӽФåɤ
.B CAP_SETPCAP
äƤʤ硢ƤӽФϥ顼
.B EPERM
ǼԤ롣
.I arg2
˻ꤵ줿ѥӥƥͭǤʤ硢
.B EINVAL
ǼԤ롣
ե륱ѥӥƥͥͭˤʤäƤʤ
(ξˤϥХǥ󥰥åȤݡȤʤ)
.B EINVAL
ǼԤ롣
.TP
.BR PR_SET_DUMPABLE " (Linux 2.3.20 ʹ)"
(Linux 2.3.20 ʹ)
ǥեȤο񤤤Ǥϥפ褦ʥʥȤˡ
פ뤫ɤꤹե饰ꤹ
(̾盧Υե饰ϡǥեȤǤϥåȤƤ뤬
set-user-ID 뤤 set-group-ID ץब¹Ԥ줿ꡢ
ޤޤʥƥॳˤäƥץ UID  GID 줿Ȥ
ꥢ)
2.6.12 ΥͥǤϡ
.I arg2
 0 (ץϥԲ) 뤤 1 (ץϥײǽ) 
ɤ餫ǤʤФʤʤ
2.6.13  2.6.17 ޤǤΥͥǤϡ 2 ǧƤ
ͤꤹȡ̾ϥפʤХʥ꤬ root 
ɤ߹߲ǽʷǥפ줿
ƥͳ顢εǽϺ줿
.\" See http://marc.theaimsgroup.com/?l=linux-kernel&m=115270289030630&w=2
.\" Subject:    Fix prctl privilege escalation (CVE-2006-2451)
.\" From:       Marcel Holtmann <marcel () holtmann ! org>
.\" Date:       2006-07-12 11:12:00
.RB ( proc (5)

.I /proc/sys/fs/suid_dumpable
⻲)
.TP
.BR PR_GET_DUMPABLE " (Linux 2.3.20 ʹ)"
(Linux 2.3.20 ʹ)
ƤӽФץˤײǽե饰
ߤξ֤ (ؿ֤ͤȤ) ֤
.\" [׽] Linux 2.6.13 ʹߤǤϡײǽե饰 2 Ȥ뤳Ȥ
.\" Ǥ뤬2.6.13 Ǥ PR_GET_DUMPABLE ϥײǽե饰 0 ʳ
.\" ͤξ 1 ֤Ǥ롣 2.6.14 ǽ줿
.TP
.BR PR_SET_ENDIAN " (Linux 2.6.18 ʹߡPowerPC Τ)"
ƤӽФץΥǥ (endian-ness) 
\fIarg2\fP ǻꤵ줿ͤꤹ롣
Ǥͤ
.\" 줾 0, 1, 2
.BR PR_ENDIAN_BIG ,
.BR PR_ENDIAN_LITTLE ,
.B PR_ENDIAN_PPC_LITTLE
(PowerPC ȥ륨ǥ)
Τ줫ĤǤ롣
.TP
.BR PR_GET_ENDIAN " (Linux 2.6.18 ʹߡPowerPC Τ)"
ƤӽФץΥǥ (endian-ness) 
.I "(int\ *) arg2"
ؤ˳Ǽ֤
.TP
.BR PR_SET_FPEMU " (Linux 2.4.18 ʹ, 2.5.9, ia64 Τ)"
ưߥ졼 (floating-point emulation) ӥåȤ
\fIarg2\fP ǻꤵ줿ͤꤹ롣
Ǥͤ \fBPR_FPEMU_NOPRINT\fP (ư̿ᥢۤä
ߥ졼Ȥ)  \fBPR_FPEMU_SIGFPE\fP (ư̿򥨥ߥ졼Ȥ

.B SIGFPE
) Ǥ롣
.TP
.BR PR_GET_FPEMU " (Linux 2.4.18 ʹ, 2.5.9, ia64 Τ)"
ưߥ졼ӥåȤͤ
.I "(int\ *) arg2"
ؤ˳Ǽ֤
.TP
.BR PR_SET_FPEXC " (Linux 2.4.21  2.5.32 ʹߡPowerPC Τ)"
ư㳰⡼ (floating-point exception mode) 
\fIarg2\fP ǻꤵ줿ͤꤹ롣
ǤΤϰʲͤǤ:
\fBPR_FP_EXC_SW_ENABLE\fP (FPEXC ư㳰ͭˤ)
\fBPR_FP_EXC_DIV\fP (0 )
\fBPR_FP_EXC_OVF\fP (Сե)
\fBPR_FP_EXC_UND\fP (ե)
\fBPR_FP_EXC_RES\fP (Τʷ (inexact result))
\fBPR_FP_EXC_INV\fP (̿ (invalid operation))
\fBPR_FP_EXC_DISABLED\fP (ư㳰̵ˤ)
\fBPR_FP_EXC_NONRECOV\fP (async non-recoverable exception mode)
\fBPR_FP_EXC_ASYNC\fP (async recoverable exception mode)
\fBPR_FP_EXC_PRECISE\fP (precise exception mode)
.TP
.BR PR_GET_FPEXC "(Linux 2.4.21  2.5.32 ʹߡPowerPC Τ)"
ư㳰⡼ɤͤ
.I "(int\ *) arg2"
ؤ˳Ǽ֤
.TP
.BR PR_SET_KEEPCAPS " (Linux 2.2.18 ʹ)"
åɤΡ֥ѥӥƥݻץե饰ꤹ롣
Υե饰ϡåɤμ UID¸ UID¸ set-user-ID ΤʤȤ
Ĥ 0 Ǥä֤顢Ƥ 0 ʳѹ줿Ȥ
åɤμ¸/ĤΥѥӥƥ礬ꥢ뤫ɤꤹ
(ǥեȤǤϡΥѥӥƥϥꥢ)
.I arg2
 0 (ѥӥƥ򥯥ꥢ) 뤤 1 (ѥӥƥݻ) 
ɤ餫ǤʤФʤʤ
.BR execve (2)
ƤӽФȡͤ 0 ˥ꥻåȤ롣
.TP
.BR PR_GET_KEEPCAPS " (Linux 2.2.18 ʹ)"
ƤӽФåɤˤ֥ѥӥƥݻץե饰
ߤξ֤ (ؿ֤ͤȤ) ֤
.TP
.BR PR_SET_NAME " (Linux 2.6.9 ʹ)"
ƤӽФץΥץ̾
.I "(char\ *) arg2"
ؤ˳Ǽ줿ͤȤäꤹ롣
̾Ϻ 16 ХȤǤꡢ
.\" TASK_COMM_LEN in include/linux/sched.h
꾯ʤХȿξ NULL ǽü٤Ǥ롣
.TP
.BR PR_GET_NAME " (Linux 2.6.11 ʹ)"
ƤӽФץΥץ̾
.I "(char\ *) arg2"
ؤ˳Ǽ֤
ХåեϺ 16 ХȤǼǤ褦ˤ٤Ǥ롣
֤ʸϡĹ 16 ХȤû NULL ü롣
.TP
.BR PR_SET_PDEATHSIG " (Linux 2.1.57 ʹ)"
ƥץ˴ʥ (parent process death signal)  \fIarg2\fP ꤹ
(Ǥ륷ʥͤϰϤ 1..maxsig Ǥꡢ0 ΤβǤ)
ƤӽФץοƥץݤˡꤷͤ
ʥȤΤ롣ͤ
.BR fork (2)
λҥץǤϲ롣
.TP
.BR PR_GET_PDEATHSIG " (Linux 2.3.15 ʹ)"
ƥץ˴ʥθߤͤ
.I "(int\ *) arg2"
ؤ˳Ǽ֤
.TP
.BR PR_SET_SECCOMP " (Linux 2.6.23 ʹ)"
.\" See http://thread.gmane.org/gmane.linux.kernel/542632
.\" [PATCH 0 of 2] seccomp updates
.\" andrea@cpushare.com
ƤӽФåɤ secure computing ⡼ɤꤹ롣
ߤμǤϡ
.I arg2
 1 ˤʤФʤʤ
secure computing ⡼ɤ 1 ꤹȡ
ΥåɤƤӽФĤ륷ƥॳ
.BR read (2),
.BR write (2),
.BR _exit (2),
.BR sigreturn (2)
ˤʤ롣
ʳΥƥॳƤӽФȡʥ
.B SIGKILL
롣
ѥפ䥽åȤɤ߹ǤʤХȥɤ¹Ԥ
ɬפ̤α黻Ԥץꥱˤơ
secure computing ⡼ɤΩġ
ѤǤΤϡͥ뤬 CONFIG_SECCOMP ͭˤ
ƤǤ롣
.TP
.BR PR_GET_SECCOMP " (Linux 2.6.23 ʹ)"
ƤӽФåɤ secure computing ⡼ɤ֤
ߤμ (⡼ɤ 1 ) ϤޤΩʤ
¾Υ⡼ɤΩĤ褦ˤʤ뤫⤷ʤ
ƤӽФåɤ secure computing ⡼ɤǤʤä硢
 0 ֤
ƤӽФåɤ secure computing ⡼ɤξ硢
.BR prctl ()
ƤӽФȥʥ
.B SIGKILL
Υץ롣
ѤǤΤϡͥ뤬 CONFIG_SECCOMP ͭˤ
ƤǤ롣
.TP
.BR PR_SET_SECUREBITS " (Linux 2.6.26 ʹ)"
ƤӽФåɤ "securebits" ե饰
.I arg2
Ϥ줿ͤꤹ롣
.BR capabilities (7)
ȡ
.TP
.BR PR_GET_SECUREBITS " (Linux 2.6.26 ʹ)"
ƤӽФåɤ "securebits" ե饰
(ؿ֤ͤȤ) ֤
.BR capabilities (7)
ȡ
.TP
.BR PR_SET_TIMING " (Linux 2.6.0-test4 ʹ)"
(̾ΡŪ˻ȤƤ) Ūʥץߥ󥰤Ѥ뤫
Τʥॹפ˴Ťץߥ󥰤Ѥ뤫ꤹ롣
\fIarg2\fP ˻Ǥͤ
.B PR_TIMING_STATISTICAL
.\" 0

.B PR_TIMING_TIMESTAMP
.\" 1
Ǥ롣
.B PR_TIMING_TIMESTAMP
ϸߤΤȤƤʤ
(Υ⡼ɤꤷ褦Ȥȥ顼
.B EINVAL
뤳Ȥ)
.\" 2.6.26-rc8 Ǥ PR_TIMING_TIMESTAMP ϲ⤷ʤ
.\" ѥå򸫤ˤⲿ򤷤Ȥʤ
.TP
.BR PR_GET_TIMING " (Linux 2.6.0-test4 ʹ)"
߻Υץߥ󥰤ˡ֤
.TP
.BR PR_SET_TSC " (Linux 2.6.26 ʹ, x86 Τ)"
Υץॹס󥿤ɤ߽Ф뤫ꤹ
ե饰ξ֤ꤹ롣
ɤ߽ФĤ
.I arg2

.B PR_TSC_ENABLE
򡢤Υץॹס󥿤ɤ߽ФȤݤ
.B SIGSEGV
ȯˤ
.B PR_TSC_SIGSEGV
Ϥ
.TP
.BR PR_GET_TSC " (Linux 2.6.26 ʹ, x86 Τ)"
Υץॹס󥿤ɤ߽Ф뤫ꤹ
ե饰ξ֤
.I "(int\ *) arg2"
ؤ˳Ǽ֤
.TP
.B PR_SET_UNALIGN
(ia64 Ǥ Linux 2.3.48 ʹ;
parisc Ǥ Linux 2.6.15 ʹ;
PowerPC Ǥ Linux 2.6.18 ʹ;
Alpha ǤϡLinux 2.6.22 ʹ;
ΥƥΤ)
unaligned ӥåȤ \fIarg2\fP ǻꤵ줿ͤꤹ롣
Ǥͤ \fBPR_UNALIGN_NOPRINT\fP (unaligned ʥ桼ۤä
)  \fBPR_UNALIGN_SIGBUS\fP (unaligned ʥ桼ä
.B SIGBUS
) Ǥ롣
.TP
.B PR_GET_UNALIGN
(Сȥƥξ
.B PR_SET_UNALIGN
)
unaligned ӥåȤͤ
.I "(int\ *) arg2"
ؤ˳Ǽ֤
.SH ֤
ȡ
.BR PR_GET_DUMPABLE ,
.BR PR_GET_KEEPCAPS ,
.BR PR_CAPBSET_READ ,
.BR PR_GET_TIMING ,
.BR PR_GET_SECUREBITS ,
.BR PR_GET_SECCOMP
ϾҤǤʤ֤ͤ
.RB ( PR_GET_SECCOMP
֤ʤ⤢)
.I option
¾ͤξ 0 ֤
顼ξ硢\-1 ֤
.I errno
Ŭڤͤꤹ롣
.SH 顼
.TP
.B EFAULT
.I arg2
ʥɥ쥹Ǥ롣
.TP
.B EINVAL
.I option
ͤǤʤ
.TP
.B EINVAL
.I arg2
ꤵ줿
.I option
ͭͤǤϤʤ
.TP
.B EINVAL
.I option

.BR PR_SET_SECCOMP

.BR PR_GET_SECCOMP
ͥ뤬
.B CONFIG_SECCOMP
ͭˤƺƤʤä
.TP
.B EPERM
.I option

.B PR_SET_SECUREBITS
ǡƤӽФѥӥƥ
.B CAP_SETPCAP
äƤʤ
ޤϡ"locked" ե饰褦Ȥ
ޤϡlocked ե饰åȤƤե饰򥻥åȤ褦Ȥ
.RB ( capabilities (7)
)
.TP
.B EPERM
.I option

.B PR_SET_KEEPCAPS
ǡƤӽФΥե饰
.B SECURE_KEEP_CAPS_LOCKED
åȤƤ
.RB ( capabilities (7)
)
.TP
.B EPERM
.I option

.B PR_CAPBSET_DROP
ǡƤӽФѥӥƥ
.B CAP_SETPCAP
äƤʤ
.\" The following can't actually happen, because prctl() in
.\" seccomp mode will cause SIGKILL.
.\" .TP
.\" .B EPERM
.\" .I option
.\" is
.\" .BR PR_SET_SECCOMP ,
.\" and secure computing mode is already 1.
.SH С
.BR prctl ()
ƥॳ Linux 2.1.57 Ƴ줿
.\" 饤֥ꡦ󥿥ե glibc 2.0.6 ɲä줿
.SH 
Υ Linux ͭǤ롣
IRIX ˤ
.BR prctl ()
ƥࡦ뤬뤬 (MIPS ƥˤ
irix_prctl Ȥ Linux 2.1.44 ƱͤƳ줿)
Υץȥפ
.sp
.BI "ptrdiff_t prctl(int " option ", int " arg2 ", int " arg3 );
.sp
Ǥ롣桼Υץ륪ץ
ץλѤǤץå륪ץ
Υץ(block)Ƥ뤫ɤĴ٤륪ץ
åκͤμԤʤץʤɤ롣
.SH Ϣ
.BR signal (2),
.BR core (5)