.\" Copyright (c) 2006, 2008 by Michael Kerrisk <mtk.manpages@gmail.com>
.\"
.\" 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.\" manual page may be incorrect or out-of-date.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.
.\"
.\" Japanese Version Copyright (c) 2006-2008 Akihiro MOTOKI
.\" Translated 2006-04-15, Akihiro MOTOKI <amotoki@dd.iij4u.or.jp>
.\" Updated 2007-01-05, Akihiro MOTOKI, LDP v2.43
.\" Updated 2007-09-03, Akihiro MOTOKI, LDP v2.64
.\" Updated 2008-08-10, Akihiro MOTOKI, LDP v3.05
.\" Updated 2008-09-19, Akihiro MOTOKI, LDP v3.08
.\"
.TH CORE 5 2008-08-26 "Linux" "Linux Programmer's Manual"
.SH ̾
core \- ץե
.SH 
ΥʥΥǥեȤΥϡ
ץλ (terminate)
.I "ץե (core dump file)"
뤳ȤǤ롣ץեϡǥ
λΥץΥꥤ᡼ƤȤեǤ롣
Υ᡼ǥХå (㤨
.BR gdb (1))
ɤ߹ǡ
ץबλΥץξ֤򸡺뤳ȤǤ롣
ɤΥʥȤ˥ץפ뤫ΥꥹȤ
.BR signal (7)
˽񤫤Ƥ롣

ץϥեȡ꥽
.B RLIMIT_CORE
ꤹ뤳Ȥǡ֥סץʥݤ
ץեΥ˾¤ݤȤǤ롣ܺ٤
.BR getrlimit (2)
򻲾ȡ

ץե뤬ʤĤ:
.IP * 3
ץե񤭹Ĥʤ
(ǥեȤǤϡե
.I core
Ȥ̾ǡȡ󥰡ǥ쥯ȥ롣
̿̾§ξܺ٤ϲ򻲾)
ե褦Ȥǥ쥯ȥ꤬񤭹߲ǽǤʤ硢
⤷Ʊ̾Υե뤬¸ߤΥե뤬񤭹߲ǽǤ
̾ΥեǤʤ (㤨Сǥ쥯ȥ䥷ܥå)
եϼԤ롣
.IP *
פ˻ȤȤΤƱ̾ (񤭹߲ǽʡ̾) ե뤬
Ǥ¸ߤΥեФϡɥ󥯤 2İʾ夢硣
.IP *
ץե褦Ȥե륷ƥबեǤ뤫
inode ƻѤƤ뤫ɤ߹ѤǥޥȤƤ硣
ޤϡΥ桼Υǥ̤Υե륷ƥ
 (quota) ãƤ롣
.IP *
ץե褦Ȥǥ쥯ȥ꤬¸ߤʤ硣
.IP *
ץΥ꥽
.B RLIMIT_CORE
(եΥ) 
.B RLIMIT_FSIZE
(ե륵)  0 ꤵƤ硣
.BR getrlimit (2)
䥷
.I ulimit
ޥɤΥɥ
.RB ( csh (1)

.IR limit )
򻲾ȡ
.IP *
ץ¹ԤХʥեɤ߽ФĤͭˤʤäƤʤ硣
.IP *
ץ¹ԤƤ set-user-ID (set-group-ID) ץνͭԤ
桼 (롼) ץμ UID ( GID) Ȱۤʤ
(â
.BR prctl (2)
.B PR_SET_DUMPABLE
ȡ
.BR proc (5)

.I /proc/sys/fs/suid_dumpable
ե⻲ȤΤ)
.\" FIXME . Perhaps relocate discussion of /proc/sys/fs/suid_dumpable
.\" and PR_SET_DUMPABLE to this page?
.SS ץե̾
.\" motoki XXX ƱƤʣƽ񤫤Ƥ롣
ǥեȤǤϡץե̾
.I core
Ȥʤ뤬ץե̾Τ˻Ȥƥץ졼Ȥ
.I /proc/sys/kernel/core_pattern
ե뤳Ȥǡե̾ѹ뤳ȤǤ
.RI ( /proc/sys/kernel/core_pattern
 Linux 2.6  2.4.21 ʹߤѤǤ)
ƥץ졼Ȥˤ % ؼ (specifier) 뤳ȤǤ롣
ϥե뤬ݤˡʲ֤ͤ롣
.PP
.RS 4
.PD 0
.TP 4
%%
1 Ĥ % ʸ
.TP
%p
פ줿ץΥץID (PID)
.TP
%u
פ줿ץμ¥桼 ID (real UID)
.TP
%g
פ줿ץμ¥롼 ID (real GID)
.TP
%s
פʥֹ
.TP
%t
׻ ( (1970 ǯ 1  1  0:00) ÿɽ)
.TP
%h
ۥ̾ (\fBuname\fP(2) ֤ \fInodename\fP Ʊ)
.TP
%e
¹ԥե̾ (ѥ̾Υץեåϴޤޤʤ)
.TP
%c
å夷ץΥեΥ˴ؤ륽եȥ꥽
(Linux 2.6.24 ʹ)
.PD
.RE
.PP
ƥץ졼Ȥ 1 Ĥ % 硢
 % ϥե̾ˤϴޤʤޤ󤵤
ʤ % ʸȤ߹碌äƱͤǤ롣
ƥץ졼Ȥˤ¾ʸϡ
ե̾ȤƤΤޤ޻Ȥ롣
ƥץ졼Ȥˤ \(aq/\(aq ʸ뤳ȤǤ
ǥ쥯ȥ̾ζڤʸȲᤵ롣
̤Ȥ륳ե̾κ祵 128 ХȤǤ
(2.6.19 ΥͥǤ 64 Х)
ΥեΥǥեͤ "core" Ǥ롣
ΤΤȤθߴΤᡢ
.I /proc/sys/kernel/core_pattern
 "%p" ޤޤ줺

.I /proc/sys/kernel/core_uses_pid
()  0 Ǥʤϡ.PID ե̾ɲä롣

С 2.4 ʹߤ Linux Ǥ
ץե̾椹븶Ūˡ󶡤Ƥ롣
.I /proc/sys/kernel/core_uses_pid
ե 0 񤫤Ƥ硢ץեñ
.I core
Ȥ̾ˤʤ롣Υե 0 ʳͤ񤫤Ƥ硢
ץե
.I core.PID
Ȥ̾ˤʤꡢե̾˥ץ ID ޤޤ롣
.SS פΥץؤΥѥ
ͥ 2.6.19 ʹߤǤϡLinux 
.I /proc/sys/kernel/core_pattern
ե̤ιʸ򥵥ݡȤƤ롣
Υեκǽʸѥ׵ (\fB|\fP) ǤС
ιԤλĤʬϼ¹ԤץȤƲᤵ롣
פϡǥΥե˽񤭹ޤΤǤϤʤ
ץɸϤȤϤ롣
ʲդ뤳ȡ
.IP * 3
ץХѥ̾ (⤷ϥ롼ȥǥ쥯ȥ \fI/\fP 
Хѥ̾) ǻꤵʤФʤʤ
ޤ'|' ʸľ夫ϤʤФʤʤ
.IP *
ץ¹Ԥ뤿ץϡ
桼롼פȤ
.I root 
ȤƼ¹Ԥ롣
.IP *
ޥɥ饤ץͿ뤳ȤǤ (ͥ 2.6.24 ʹ)
ϥۥ磻ȥڡǶڤ
(1ԤκĹ 128 ХȤ¤Ǥ)
.IP *
ޥɥ饤ˤϡ嵭ΥꥹȤˤ % ؼҤޤ뤳ȤǤ롣
㤨Сפץ PID Ϥˤϡ

.I %p
ꤹ롣
.SS ɤΥޥåԥ󥰤򥳥פ˽񤭹फ椹
ͥ 2.6.23 ʹߤǤϡLinux ͭΥե
.I /proc/PID/coredump_filter
Ȥäơбץ ID ĥץФƥפԤ
ݤˡɤΥꥻȤ򥳥ץե˽񤭹फǤ롣

Υեͤϥޥåԥ󥰼
.RB ( mmap (2)
) ΥӥåȥޥǤ롣
ޥΤӥåȤåȤȡΥӥåȤб̤
ޥåԥ󥰤פ롣åȤƤʤΤϥפʤ
ΥեγƥӥåȤϰʲΰ̣ġ
.PP
.PD 0
.RS 4
.TP
bit 0
̵̾Υץ饤١ȥޥåԥ (anonymous private mappings) פ롣
.TP
bit 1
̵̾ζͭޥåԥ (anonymous shared mappings) פ롣
.TP
bit 2
եȴϢդ줿ץ饤١ȥޥåԥ
(file-backed private mappings) פ롣
.TP
bit 3
եȴϢդ줿ͭޥåԥ
(file-backed shared mappings) פ롣
.\" file-backed shared mappings of course also update the underlying
.\" mapped file.
.RE
.PD
.PP
.I coredump_filter
Υǥեͤ 0x3 Ǥ롣
ͤΤ Linux εưȿǤΤǤꡢ
̵̾ꥻ (anonymous memory segments) פ
Ȥ̣롣

.I coredump_filter
ͤ˴ؤ餺ե졼Хåեʤɤ memory-mapped I/O ˴ؤ
ڡϷ褷ƥפ줺 DSO ڡϾ˥פ롣

.BR fork (2)
ǺҥץϿƥץ
.I coredump_filter
ͤѾ롣
.BR execve (2)

.I coredump_filter
ͤݻ롣

Τ褦ˡץ¹Ԥ˿ƥ
.I coredump_filter
ꤷƤΩĤȤ롣

.in +4n
.nf
.RB "$" " echo 0x7 > /proc/self/coredump_filter"
.RB "$" " ./some_program"
.fi
.in
.PP
Υե뤬󶡤Τϡͥ뤬ꥪץ
.B CONFIG_ELF_CORE
ͭˤƺ줿Ǥ롣
.SH 
.BR gdb (1)

.I gcore
ޥɤѤȡ¹ΥץΥפǤ롣

ޥåɥץ
(Τˤϡ
.BR clone (2)

.B CLONE_VM
줿̥ץȥͭƤץ)
פ硢
ե̾˥ץ ID ɬղä롣

.I /proc/sys/kernel/core_pattern
 %p ˤꥳե̾Τɤ¾ξ˥ץ ID 
Ǥ˴ޤޤƤϡץ ID ղäʤ
(εǽޤΩĤΤ LinuxThreads ѤƤǤ롣
LinuxThreads ǤϡץθġΥåɤϰۤʤץ ID
ġ)
.\" Always including the PID in the name of the core file made
.\" sense for LinuxThreads, where each thread had a unique PID,
.\" but doesn't seem to serve any purpose with NPTL, where all the 
.\" threads in a process share the same PID (as POSIX.1 requires).  
.\" Probably the behavior is maintained so that applications using 
.\" LinuxThreads continue appending the PID (the kernel has no easy 
.\" way of telling which threading implementation the userspace 
.\" application is using). -- mtk, April 2006
.SH 
ʲΥץ
.I /proc/sys/kernel/core_pattern
եΥѥ׹ʸλ򼨤Ƥ롣
ʲΥΥåϤΥץλ򼨤ΤǤ
(ѥ뤷
.I core_pattern_pipe_test
Ȥ̾μ¹ԥեƤ)
.PP
.in +4n
.nf
.RB "$" " cc \-o core_pattern_pipe_test core_pattern_pipe_test.c"
.RB "$" " su"
Password:
.RB "#" " echo \(aq|$PWD/core_pattern_pipe_test %p \
UID=%u GID=%g sig=%s\(aq > \e"
.B "    /proc/sys/kernel/core_pattern"
.RB "#" " exit"
.RB "$" " sleep 100"
.BR "^\e" "                     # type control-backslash"
Quit (core dumped)
.RB "$" " cat core.info"
argc=5
argc[0]=</home/mtk/core_pattern_pipe_test>
argc[1]=<20575>
argc[2]=<UID=1000>
argc[3]=<GID=100>
argc[4]=<sig=3>
Total bytes in core dump: 282624
.fi
.in
.SS ץΥ
\&
.nf
/* core_pattern_pipe_test.c */

#define _GNU_SOURCE
#include <sys/stat.h>
#include <fcntl.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

#define BUF_SIZE 1024

int
main(int argc, char *argv[])
{
    int tot, j;
    ssize_t nread;
    char buf[BUF_SIZE];
    FILE *fp;
    char cwd[PATH_MAX];

    /* Change our current working directory to that of the
       crashing process */

    snprintf(cwd, PATH_MAX, "/proc/%s/cwd", argv[1]);
    chdir(cwd);

    /* Write output to file "core.info" in that directory */

    fp = fopen("core.info", "w+");
    if (fp == NULL)
        exit(EXIT_FAILURE);

    /* Display command\-line arguments given to core_pattern
       pipe program */

    fprintf(fp, "argc=%d\\n", argc);
    for (j = 0; j < argc; j++)
        fprintf(fp, "argc[%d]=<%s>\\n", j, argv[j]);

    /* Count bytes in standard input (the core dump) */

    tot = 0;
    while ((nread = read(STDIN_FILENO, buf, BUF_SIZE)) > 0)
        tot += nread;
    fprintf(fp, "Total bytes in core dump: %d\\n", tot);

    exit(EXIT_SUCCESS);
}
.fi
.SH Ϣ
.BR bash (1),
.BR gdb (1),
.BR getrlimit (2),
.BR mmap (2),
.BR prctl (2),
.BR sigaction (2),
.BR elf (5),
.BR proc (5),
.BR pthreads (7),
.BR signal (7)