#Bash 的 setarch 命令

SETARCH(8)                   System Administration                  SETARCH(8)

NAME
       setarch - change reported architecture in new program environment
       and/or set personality flags

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

       setarch --list|-h|-V

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

DESCRIPTION
       setarch modifies execution domains and process personality flags.

       The execution domains 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 can
       also be used to set various personality options. The default program is
       /bin/sh.

       Since version 2.33 the arch command line argument is optional and
       setarch may be used to change personality flags (ADDR_LIMIT_*,
       SHORT_INODE, etc) without modification of the execution domain.

OPTIONS
       --list
           List the architectures that setarch knows about. Whether setarch
           can actually set each of these architectures depends on the running
           kernel.

       --show[=personality]
           Show the currently active personality and flags. If the personality
           argument is provided, it is shown instead of the current one.
           personality is a hexadecimal number with values was described in
           sys/personality.h.

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

       -v, --verbose
           Be verbose.

       -3, --3gb
           Specifies program should use a maximum of 3GB of address space.
           Supported on x86. Turns on ADDR_LIMIT_3GB.

       --4gb
           This option has no effect. It is retained for backward
           compatibility only, and may be removed in future releases.

       -B, --32bit
           Limit the address space to 32 bits to emulate hardware. Supported
           on ARM and Alpha. Turns on ADDR_LIMIT_32BIT.

       -F, --fdpic-funcptrs
           Treat user-space function pointers to signal handlers as pointers
           to address descriptors. This option has no effect on architectures
           that do not support FDPIC ELF binaries. In kernel v4.14 support is
           limited to ARM, Blackfin, Fujitsu FR-V, and SuperH CPU
           architectures.

       -I, --short-inode
           Obsolete bug emulation flag. Turns on SHORT_INODE.

       -L, --addr-compat-layout
           Provide legacy virtual address space layout. Use when the program
           binary does not have PT_GNU_STACK ELF header. Turns on
           ADDR_COMPAT_LAYOUT.

       -R, --addr-no-randomize
           Disables randomization of the virtual address space. Turns on
           ADDR_NO_RANDOMIZE.

       -S, --whole-seconds
           Obsolete bug emulation flag. Turns on WHOLE_SECONDS.

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

       -X, --read-implies-exec
           If this is set then mmap(2) PROT_READ will also add the PROT_EXEC
           bit - as expected by legacy x86 binaries. Notice that the ELF
           loader will automatically set this bit when it encounters a legacy
           binary. Turns on READ_IMPLIES_EXEC.

       -Z, --mmap-page-zero
           SVr4 bug emulation that will set mmap(2) page zero as read-only.
           Use when program depends on this behavior, and the source code is
           not available to be fixed. Turns on MMAP_PAGE_ZERO.

       -h, --help
           Display help text and exit.

       -V, --version
           Print version and exit.

EXAMPLE
           setarch --addr-no-randomize mytestprog
           setarch ppc32 rpmbuild --target=ppc --rebuild foo.src.rpm
           setarch ppc32 -v -vL3 rpmbuild --target=ppc --rebuild bar.src.rpm
           setarch ppc32 --32bit rpmbuild --target=ppc --rebuild foo.src.rpm

AUTHORS
       Elliot Lee <sopwith@redhat.com>, Jindrich Novy <jnovy@redhat.com>,
       Karel Zak <kzak@redhat.com>

SEE ALSO
       personality(2), select(2)

REPORTING BUGS
       For bug reports, use the issue tracker at
       https://github.com/util-linux/util-linux/issues.

AVAILABILITY
       The setarch command is part of the util-linux package which can be
       downloaded from Linux Kernel Archive
       <https://www.kernel.org/pub/linux/utils/util-linux/>.

util-linux 2.39.3                 2023-11-21                        SETARCH(8)