1SETARCH(8) System Administration SETARCH(8)
2
6 setarch - change reported architecture in new program environment and
7 set personality flags
8
10 setarch arch [options] [program [argument...]]
11 arch [options] [program [argument...]]
13 setarch --list|-h|-V
15
17 setarch currently only affects the output of uname -m. For example, on
18 an AMD64 system, running setarch i386 program will cause program to see
19 i686 instead of x86_64 as the machine type. It also allows to set var‐
20 ious personality options. The default program is /bin/sh.
21
23 --list List the architectures that setarch knows about. Whether
24 setarch can actually set each of these architectures depends on
25 the running kernel.
26 --uname-2.6
28 Causes the program to see a kernel version number beginning with
29 2.6. Turns on UNAME26.
30 -v, --verbose
32 Be verbose.
33 -3, --3gb
35 Specifies program should use a maximum of 3GB of address space.
36 Supported on x86. Turns on ADDR_LIMIT_3GB.
37 --4gb This option has no effect. It is retained for backward compati‐
39 bility only, and may be removed in future releases.
40 -B, --32bit
42 Limit the address space to 32 bits to emulate hardware. Sup‐
43 ported on ARM and Alpha. Turns on ADDR_LIMIT_32BIT.
44 -F, --fdpic-funcptrs
46 Treat user-space function pointers to signal handlers as point‐
47 ers to address descriptors. This option has no effect on archi‐
48 tectures that do not support FDPIC ELF binaries. In kernel
49 v4.14 support is limited to ARM, Blackfin, Fujitsu FR-V, and
50 SuperH CPU architectures.
51 -I, --short-inode
53 Obsolete bug emulation flag. Turns on SHORT_INODE.
54 -L, --addr-compat-layout
56 Provide legacy virtual address space layout. Use when the pro‐
57 gram binary does not have PT_GNU_STACK ELF header. Turns on
58 ADDR_COMPAT_LAYOUT.
59 -R, --addr-no-randomize
61 Disables randomization of the virtual address space. Turns on
62 ADDR_NO_RANDOMIZE.
63 -S, --whole-seconds
65 Obsolete bug emulation flag. Turns on WHOLE_SECONDS.
66 -T, --sticky-timeouts
68 This makes select(2), pselect(2), and ppoll(2) system calls pre‐
69 serve the timeout value instead of modifying it to reflect the
70 amount of time not slept when interrupted by a signal handler.
71 Use when program depends on this behavior. For more details see
72 the timeout description in select(2) manual page. Turns on
73 STICKY_TIMEOUTS.
74 -X, --read-implies-exec
76 If this is set then mmap(3) PROT_READ will also add the
77 PROT_EXEC bit - as expected by legacy x86 binaries. Notice that
78 the ELF loader will automatically set this bit when it encoun‐
79 ters a legacy binary. Turns on READ_IMPLIES_EXEC.
80 -Z, --mmap-page-zero
82 SVr4 bug emulation that will set mmap(3) page zero as read-only.
83 Use when program depends on this behavior, and the source code
84 is not available to be fixed. Turns on MMAP_PAGE_ZERO.
85 -V, --version
87 Display version information and exit.
88 -h, --help
90 Display help text and exit.
91
93 setarch ppc32 rpmbuild --target=ppc --rebuild foo.src.rpm
94 setarch ppc32 -v -vL3 rpmbuild --target=ppc --rebuild bar.src.rpm
95 setarch ppc32 --32bit rpmbuild --target=ppc --rebuild foo.src.rpm
96
98 Elliot Lee ⟨sopwith@redhat.com⟩
99 Jindrich Novy ⟨jnovy@redhat.com⟩
100
102 personality(2), select(2)
103
105 The setarch command is part of the util-linux package and is available
106 from Linux Kernel Archive ⟨https://www.kernel.org/pub/linux/utils/util-
107 linux/⟩.
108util-linux December 2017 SETARCH(8)