1SETARCH(8) System Administration SETARCH(8)
2
6 setarch - change reported architecture in new program environment
7 and/or set personality flags
8
10 setarch [arch] [options] [program [argument...]]
11 setarch --list|-h|-V
13 arch [options] [program [argument...]]
15
17 setarch modifies execution domains and process personality flags.
18 The execution domains currently only affects the output of uname -m.
20 For example, on an AMD64 system, running setarch i386 program will
21 cause program to see i686 instead of x86_64 as the machine type. It can
22 also be used to set various personality options. The default program is
23 /bin/sh.
24 Since version 2.33 the arch command line argument is optional and
26 setarch may be used to change personality flags (ADDR_LIMIT_*,
27 SHORT_INODE, etc) without modification of the execution domain.
28
30 --list
31 List the architectures that setarch knows about. Whether setarch
32 can actually set each of these architectures depends on the running
33 kernel.
34 --uname-2.6
36 Causes the program to see a kernel version number beginning with
37 2.6. Turns on UNAME26.
38 -v, --verbose
40 Be verbose.
41 -3, --3gb
43 Specifies program should use a maximum of 3GB of address space.
44 Supported on x86. Turns on ADDR_LIMIT_3GB.
45 --4gb
47 This option has no effect. It is retained for backward
48 compatibility only, and may be removed in future releases.
49 -B, --32bit
51 Limit the address space to 32 bits to emulate hardware. Supported
52 on ARM and Alpha. Turns on ADDR_LIMIT_32BIT.
53 -F, --fdpic-funcptrs
55 Treat user-space function pointers to signal handlers as pointers
56 to address descriptors. This option has no effect on architectures
57 that do not support FDPIC ELF binaries. In kernel v4.14 support is
58 limited to ARM, Blackfin, Fujitsu FR-V, and SuperH CPU
59 architectures.
60 -I, --short-inode
62 Obsolete bug emulation flag. Turns on SHORT_INODE.
63 -L, --addr-compat-layout
65 Provide legacy virtual address space layout. Use when the program
66 binary does not have PT_GNU_STACK ELF header. Turns on
67 ADDR_COMPAT_LAYOUT.
68 -R, --addr-no-randomize
70 Disables randomization of the virtual address space. Turns on
71 ADDR_NO_RANDOMIZE.
72 -S, --whole-seconds
74 Obsolete bug emulation flag. Turns on WHOLE_SECONDS.
75 -T, --sticky-timeouts
77 This makes select(2), pselect(2), and ppoll(2) system calls
78 preserve the timeout value instead of modifying it to reflect the
79 amount of time not slept when interrupted by a signal handler. Use
80 when program depends on this behavior. For more details see the
81 timeout description in select(2) manual page. Turns on
82 STICKY_TIMEOUTS.
83 -X, --read-implies-exec
85 If this is set then mmap(3p) PROT_READ will also add the PROT_EXEC
86 bit - as expected by legacy x86 binaries. Notice that the ELF
87 loader will automatically set this bit when it encounters a legacy
88 binary. Turns on READ_IMPLIES_EXEC.
89 -Z, --mmap-page-zero
91 SVr4 bug emulation that will set mmap(3p) page zero as read-only.
92 Use when program depends on this behavior, and the source code is
93 not available to be fixed. Turns on MMAP_PAGE_ZERO.
94 -V, --version
96 Display version information and exit.
97 -h, --help
99 Display help text and exit.
100
102 setarch --addr-no-randomize mytestprog
103 setarch ppc32 rpmbuild --target=ppc --rebuild foo.src.rpm
104 setarch ppc32 -v -vL3 rpmbuild --target=ppc --rebuild bar.src.rpm
105 setarch ppc32 --32bit rpmbuild --target=ppc --rebuild foo.src.rpm
106
108 Elliot Lee <sopwith@redhat.com>, Jindrich Novy <jnovy@redhat.com>,
109 Karel Zak <kzak@redhat.com>
110
112 personality(2), select(2)
113
115 For bug reports, use the issue tracker at
116 https://github.com/karelzak/util-linux/issues.
117
119 The setarch command is part of the util-linux package which can be
120 downloaded from Linux Kernel Archive
121 <https://www.kernel.org/pub/linux/utils/util-linux/>.
122util-linux 2.37.2 2021-07-20 SETARCH(8)