personality

Set the process execution domain via system call

TLDR

Disable ASLR for debugging (via setarch)

$ setarch $(uname -m) -R [command]

Run 32-bit binary on 64-bit system

$ linux32 [command]

Run 64-bit binary

$ linux64 [command]

Set legacy memory layout

$ setarch $(uname -m) -L [command]

SYNOPSIS

$ #include <sys/personality.h>

int personality(unsigned long persona);

personality(2) is a Linux system call that sets the process execution domain, telling the kernel to emulate behavior of other UNIX flavors or to toggle compatibility flags. It is primarily invoked indirectly through wrapper commands such as setarch, linux32, and linux64.Common use cases include disabling ASLR to produce reproducible memory addresses during debugging, running legacy 32-bit binaries under a 64-bit kernel, and emulating older UNIX memory layouts for compatibility.

PARAMETERS

PER_LINUX

Standard Linux execution domain.

PER_LINUX32

32-bit execution mode on 64-bit kernels.

ADDR_NO_RANDOMIZE

Disable Address Space Layout Randomization (ASLR).

MMAP_PAGE_ZERO

Map the zero page (for SVr4 binaries).

ADDR_COMPAT_LAYOUT

Use legacy virtual memory layout.

READ_IMPLIES_EXEC

Readable mappings become executable (PROTREAD implies PROTEXEC).

ADDR_LIMIT_32BIT

Limit address space to 32 bits.

STICKY_TIMEOUTS

Use SVr4-style timeout handling in select(2).

CAVEATS

Linux-specific. There is no standalone personality CLI binary; use setarch(8) or its aliases. Disabling security features such as ASLR reduces security and should be limited to debugging contexts.

HISTORY

The personality(2) system call originated in early Linux 1.2/2.x to support binary compatibility with SCO, SVr4, Solaris, and other UNIX systems whose binaries could run under Linux via iBCS2.