setarch

Change reported architecture for program execution

TLDR

Run a command as if the machine architecture is i686

$ setarch i686 [command]

Run a shell with x86_64 architecture

$ setarch x86_64 [bash]

Disable randomization of the virtual address space

$ setarch [linux32] -R [command]

List supported architectures

$ setarch --list

SYNOPSIS

setarch [arch] [options] [program [arguments]]

setarch changes the reported architecture for a program's execution environment. It modifies what uname -m reports and can affect how programs behave based on architecture detection.The command is useful for running 32-bit applications on 64-bit systems, compatibility testing, and debugging programs that behave differently based on architecture. The linux32 and linux64 symlinks are shortcuts for common uses.

PARAMETERS

arch

Target architecture (i686, x86_64, linux32, linux64, etc.)

-R, --addr-no-randomize

Disable address space layout randomization (ASLR).

-F, --fdpic-funcptrs

Treat user-space function pointers as pointers to function descriptors.

-Z, --mmap-page-zero

Turn on MMAPPAGEZERO for legacy programs.

-L, --addr-compat-layout

Use legacy virtual address space layout.

-X, --read-implies-exec

Turn on READIMPLIESEXEC.

-B, --32bit

Turn on ADDRLIMIT32BIT.

-I, --short-inode

Turn on SHORT_INODE.

-S, --whole-seconds

Turn on WHOLE_SECONDS.

-T, --sticky-timeouts

Turn on STICKY_TIMEOUTS.

-3, --3gb

Use a 3GB memory layout.

--uname-2.6

Report a 2.6 kernel version in uname.

--list

List supported architectures and exit.

-v, --verbose

Be verbose.

-h, --help

Display help.

CAVEATS

Does not enable actual architecture emulation; the underlying CPU must support the requested mode. Disabling ASLR (-R) reduces security and should only be used for debugging. Part of the util-linux package.