UNIX for Dummies Questions & Answers

[alien@Arch~/tmp]:)strace ./abc
execve("./abc", ["./abc"], [/* 31 vars */]) = 0
brk(0)                                  = 0x8714000
mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xb772c000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY)      = 3
fstat64(3, {st_mode=S_IFREG|0644, st_size=46617, ...}) = 0
mmap2(NULL, 46617, PROT_READ, MAP_PRIVATE, 3, 0) = 0xb7720000
close(3)                                = 0
open("/lib/libc.so.6", O_RDONLY)        = 3
read(3, "\177ELF\1\1\1\0\0\0\0\0\0\0\0\0\3\0\3\0\1\0\0\0\360l\1\0004\0\0\0"..., 512) = 512
fstat64(3, {st_mode=S_IFREG|0755, st_size=1558827, ...}) = 0
mmap2(NULL, 1358248, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0xb75d4000
mprotect(0xb7719000, 4096, PROT_NONE)   = 0
mmap2(0xb771a000, 12288, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x145) = 0xb771a000
mmap2(0xb771d000, 10664, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0xb771d000
close(3)                                = 0
mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xb75d3000
set_thread_area({entry_number:-1 -> 6, base_addr:0xb75d36c0, limit:1048575, seg_32bit:1, contents:0, read_exec_only:0, limit_in_pages:1, seg_not_present:0, useable:1}) = 0
mprotect(0xb771a000, 8192, PROT_READ)   = 0
mprotect(0xb774a000, 4096, PROT_READ)   = 0
munmap(0xb7720000, 46617)               = 0
--- SIGSEGV (Segmentation fault) @ 0 (0) ---
+++ killed by SIGSEGV +++
Segmentation fault

       *  The  process  does  not have permission to write the core file.  (By
          default the core file is called core, and is created in the  current
          working  directory.   See below for details on naming.)  Writing the
          core file will fail if the directory in which it is to be created is
          nonwritable,  or  if  a  file  with  the same name exists and is not
          writable or is not a regular file (e.g., it is a directory or a sym-
          bolic link).

       *  A  (writable,  regular) file with the same name as would be used for
          the core dump already exists, but there is more than one  hard  link
          to that file.

       *  The  file  system where the core dump file would be created is full;
          or has run out of inodes; or is mounted read-only; or the  user  has
          reached their quota for the file system.

       *  The  directory in which the core dump file is to be created does not
          exist.

       *  The  RLIMIT_CORE  (core  file  size)  or  RLIMIT_FSIZE  (file  size)
          resource  limits  for  the process are set to zero; see getrlimit(2)
          and the documentation  of  the  shell's  ulimit  command  (limit  in
          csh(1)).

       *  The  binary being executed by the process does not have read permis-
          sion enabled.

       *  The process is executing a set-user-ID (set-group-ID)  program  that
          is  owned  by  a user (group) other than the real user (group) ID of
          the  process.   (However,  see  the  description  of  the   prctl(2)
          PR_SET_DUMPABLE    operation,    and    the   description   of   the
          /proc/sys/fs/suid_dumpable file in proc(5).)

[alien@Arch~/tmp]:)ls -al
total 13
drwxr-xr-x  2 alien alien   96 Dec 18 15:03 .
drwxrwxrwx 25 alien alien  912 Dec 18 15:03 ..
-rwxr-xr-x  1 alien alien 4331 Dec 18 11:31 abc
-rw-r--r--  1 alien alien   56 Dec 18 11:31 abc.c
[alien@Arch~/tmp]:)./abc
Segmentation fault

/proc/sys/kernel/core_pattern

[alien@Arch~]:)cat /proc/sys/kernel/core_pattern
core