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ELFCTL(1)		    General Commands Manual		     ELFCTL(1)

NAME
       elfctl -- change	an ELF binary's	feature	control	note

SYNOPSIS
       elfctl [-h | --help] [-i] [-l] [-e featurelist] file ...

DESCRIPTION
       The  elfctl  utility modifies feature flags in the feature control note
       in an ELF binary.

       The options are as follows:

       -h | --help
	       Print a usage message and exit.

       -i      Ignore unknown feature flags in featurelist.

       -l      List known ELF feature flags.

       -e featurelist
	       Edit features from the given comma separated list  featurelist.
	       featurelist  starts  with  one  of the three operations:	"+" to
	       turn on the features, "-" to turn off the features, "=" to only
	       turn on the given features.  A comma separated list of  feature
	       names or	numeric	values follows the operation.

       If  -e  is  not specified elfctl	displays the status of each feature in
       the ELF note in each file ....

EXIT STATUS
       Exit status is 0	on success, and	1 if the command fails if a file  does
       not exist, is too short,	or fails to find or edit features note.

EXAMPLES
       The following is	an example of a	typical	usage of the elfctl command:

	     elfctl file
	     elfctl -e +noaslr file

       Features	may be specified as numerical values:

	     elfctl -e =0x0001,0x0004 file

       Features	may also be specified as a single combined value:

	     elfctl -e =0x5 file

NOTES
       On  amd64,  on  a machine with LA57 (5-level paging) mode supported and
       enabled,	if both	la57 and la48 feature flags are	 specified,  the  la57
       feature has priority over la48.	The vm.pmap.prefer_uva_la48 sysctl MIB
       defines	the  default user address space	size for binaries which	do not
       set either of these flags.

SEE ALSO
       mitigations(7)

HISTORY
       elfctl first appeared in	FreeBSD	12.2.

AUTHORS
       elfctl was written by  Bora  Ozarslan  borako.ozarslan@gmail.com	 under
       sponsorship from	the FreeBSD Foundation.

FreeBSD	15.0			October	5, 2023			     ELFCTL(1)

Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=elfctl&sektion=1&manpath=FreeBSD+15.0-RELEASE+and+Ports>

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