Linux "setarch" Command Line Options and Examples

change reported architecture in new program environment and set personality flags

setarch currently only affects the output of uname -m. For example, on an AMD64 system, running setarch i386 program will cause program to see i686 instead of x86_64 as the machine type. It also allows to set various personality options.

Usage:

setarch arch [options] [program [argument...]]


    arch [options] [program [argument...]]

setarch --list|-h|-V

Command Line Options:

--uname-2.6

Causes the program to see a kernel version number beginning with 2.6. Turns on UNAME26.


                            setarch --uname-2.6 ...

-3

Specifies program should use a maximum of 3GB of address space. Supported on x86. Turns onADDR_LIMIT_3GB.


                            setarch -3 ...

-B

Limit the address space to 32 bits to emulate hardware. Supported on ARM and Alpha. Turns onADDR_LIMIT_32BIT.


                            setarch -B ...

-F

Treat user-space function pointers to signal handlers as pointers to address descriptors. This optionhas no effect on architectures that do not support FDPIC ELF binaries. In kernel v4.14 support is lim‐ited to ARM, Blackfin, Fujitsu FR-V, and SuperH CPU architectures.


                            setarch -F ...

-I

Obsolete bug emulation flag. Turns on SHORT_INODE.


                            setarch -I ...

-L

Provide legacy virtual address space layout. Use when the program binary does not have PT_GNU_STACKELF header. Turns on ADDR_COMPAT_LAYOUT.


                            setarch -L ...

-R

Disables randomization of the virtual address space. Turns on ADDR_NO_RANDOMIZE.


                            setarch -R ...

-S

Obsolete bug emulation flag. Turns on WHOLE_SECONDS.


                            setarch -S ...

-T

This makes select(2), pselect(2), and ppoll(2) system calls preserve the timeout value instead of modi‐fying it to reflect the amount of time not slept when interrupted by a signal handler. Use when pro‐gram depends on this behavior. For more details see the timeout description in select(2) manual page.Turns on STICKY_TIMEOUTS.


                            setarch -T ...

-X

If this is set then mmap(3) PROT_READ will also add the PROT_EXEC bit - as expected by legacy x86 bina‐ries. Notice that the ELF loader will automatically set this bit when it encounters a legacy binary.Turns on READ_IMPLIES_EXEC.


                            setarch -X ...

-Z

SVr4 bug emulation that will set mmap(3) page zero as read-only. Use when program depends on thisbehavior, and the source code is not available to be fixed. Turns on MMAP_PAGE_ZERO.


                            setarch -Z ...

-V

Display version information and exit.


                            setarch -V ...

-h

Display help text and exit.EXAMPLESsetarch ppc32 rpmbuild --target=ppc --rebuild foo.src.rpmsetarch ppc32 -v -vL3 rpmbuild --target=ppc --rebuild bar.src.rpmsetarch ppc32 --32bit rpmbuild --target=ppc --rebuild foo.src.rpmAUTHORElliot Lee ⟨sopwith@redhat.com⟩Jindrich Novy ⟨jnovy@redhat.com⟩


                            setarch -h ...