PR_SET_DUMPABLE(2const)

NAME

PR_SET_DUMPABLE - set the "dumpable" attribute of the calling process

LIBRARY

Standard C library (libc, -lc)

SYNOPSIS

#include <linux/prctl.h>  /* Definition of PR_* constants */
#include <sys/prctl.h>

int prctl(PR_SET_DUMPABLE, long dumpable);

DESCRIPTION

Set the state of the "dumpable" attribute, which determines whether core dumps are produced for the calling process upon delivery of a signal whose default behavior is to produce a core dump.

dumpable must be either 0L (SUID_DUMP_DISABLE, process is not dumpable) or 1L (SUID_DUMP_USER, process is dumpable).

Normally, the "dumpable" attribute is set to 1. However, it is reset to the current value contained in the file /proc/sys/fs/suid_dumpable (which by default has the value 0), in the following circumstances:

•: The process's effective user or group ID is changed.
•: The process's filesystem user or group ID is changed (see credentials(7)).
•: The process executes (execve(2)) a set-user-ID or set-group-ID program, resulting in a change of either the effective user ID or the effective group ID.
•: The process executes (execve(2)) a program that has file capabilities (see capabilities(7)), but only if the permitted capabilities gained exceed those already permitted for the process.

Processes that are not dumpable can not be attached via ptrace(2) PTRACE_ATTACH; see ptrace(2) for further details.

If a process is not dumpable, the ownership of files in the process's /proc/pid directory is affected as described in proc_pid(5).

RETURN VALUE

On success, 0 is returned. On error, -1 is returned, and errno is set to indicate the error.

ERRORS

EINVAL: arg2 is neither SUID_DUMP_DISABLE nor SUID_DUMP_USER.

FILES

/proc/sys/fs/suid_dumpable
/proc/pid/

STANDARDS

Linux.

HISTORY

Linux 2.3.20.

Between Linux 2.6.13 and Linux 2.6.17, the value 2L was also permitted, which caused any binary which normally would not be dumped to be dumped readable by root only; for security reasons, this feature has been removed. (See also the description of /proc/sys/fs/suid_dumpable in proc_sys_fs(5).)