Commit Graph

16 Commits

Author SHA1 Message Date
Konstantin Belousov
9940ac808d elfctl: Fix type errors.
Target value for val has uint32_t type, not uint, adjust used constant.
Change val type to unsigned so that left and right sides of comparision
operator do not expose different signed types of same range [*].

Switch to unsigned long long and strtoll(3) so that 0x80000000 is
accepted by conversion function [**].

Reported by:	kargl [*]
Noted by:	emaste [**]
Reviewed by:	emaste
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D28301
2021-01-23 17:24:32 +02:00
Ed Maste
f302fd1aa6 elfctl: fix typo from last-minute refactoring
Reported by:	jkim
Fixes:		86f33b5fcf
2021-01-22 16:35:05 -05:00
Ed Maste
86f33b5fcf elfctl: allow features to be specified by value
This will allow elfctl on older releases to set bits that are not yet
known there, so that the binary will have the correct settings applied
if run on a later FreeBSD version.

PR:		252629 (related)
Suggested by:	kib
Reviewed by:	gbe (manpage, earlier), kib
MFC after:	3 days
Sponsored by:	The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D28284
2021-01-22 14:38:52 -05:00
Ed Maste
c763f99d11 elfctl: prefix disable flags with "no"
Some ELF feature flags indicate a request to opt-out of some feature,
for example NT_FREEBSD_FCTL_ASLR_DISABLE indicates that ASLR should be
disabled for the tagged binary.  Using "aslr" as the short name for the
flag is confusing as it seems to indicate a request for ASLR to be
enabled.  Rename "noaslr", and make a similar change for other opt-out
flags.

Reviewed by:	bapt, manu, markj
MFC after:	1 week
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D28139
2021-01-14 15:09:13 -05:00
Ed Maste
3dfcb70b6a elfctl: add backwards compatibility for "no" prefixes
I am going to prefix opt-out ELF feature flag names with "no" to make
their meaning more clear (review D28139), but there are some uses of the
existing names already (e.g., the PR referenced below).

For now accept the older, unprefixed name as well, and emit a warning.
We can revert this after FreeBSD 13 branches.

% elfctl -e +aslr foo
elfctl: interpreting aslr as noaslr; please specify noaslr

PR:		239873 (related)
MFC after:	1 week
Sponsored by:	The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D28140
2021-01-14 15:09:08 -05:00
Ed Maste
f6d95a0110 elftcl: add -i flag to ignore unknown flags
This may allow an identical elfctl invocation to be used on multiple
FreeBSD versions, with features not implemented on older releases being
silently ignored.

PR:		252629 (related)
Reviewed by:	kib
MFC after:	1 week
Sponsored by:	The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D28130
2021-01-13 00:10:13 -05:00
Konstantin Belousov
673e2dd652 Add ELF flag to disable ASLR stack gap.
Also centralize and unify checks to enable ASLR stack gap in a new
helper exec_stackgap().

PR:	239873
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2020-12-18 23:14:39 +00:00
Konstantin Belousov
bc6f027a39 Reserve FreeBSD ELF feature control bit LA48 to control VA layout on amd64.
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
Differential revision:	https://reviews.freebsd.org/D25273
2020-08-23 19:47:27 +00:00
Ed Maste
4ac4a7f80b elfctl: update earliest FreeBSD revision to 12.2
elfctl has been merged to stable/12, and so will appear in FreeBSD 12.2

Reported by:	Dewayne Geraghty
MFC after:	1 week
Sponsored by:	The FreeBSD Foundation
2020-05-05 21:50:52 +00:00
Ed Maste
b7a9e9d6b2 elfctl: remove memory leak
CID:		1420356
Reported by:	Coverity Scan
Sponsored by:	The FreeBSD Foundation
2020-03-11 13:51:01 +00:00
Ed Maste
d06e23f9d9 Reserve WXNEEDED ELF feature control flag
This will be used to tag binaries that require W+X mappings, in advance
of the ability to prevent W^X in mmap/mprotect.

There is still some discussion about the flag's name, but the ABI won't
change even if the name does (as kib pointed out in the review).

Reviewed by:	csjp, kib
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D23909
2020-03-04 18:21:30 +00:00
Ed Maste
76cd520d45 elfctl: check read return value
CID:		1420212, 1420213
Reported by:	Coverity Scan
Sponsored by:	The FreeBSD Foundation
2020-03-04 16:57:23 +00:00
Ed Maste
87a920c065 elfctl: style(9): use C99 uintX_t types
Sponsored by:	The FreeBSD Foundation
2020-03-04 16:53:49 +00:00
Ed Maste
ba6d70a065 elfctl: tiny style(9) cleanup, use bool where appropriate 2020-03-02 14:34:26 +00:00
Kyle Evans
fdafb99d81 elfctl: initialize features
GCC points out a couple levels down in convert_to_features that this may be
used uninitialized. Indeed, this is true- initialize it to NULL so that we
at least deref a null pointer.
2020-03-02 04:22:38 +00:00
Ed Maste
79bfb05b07 Move ELF feature note tool to usr.bin/elfctl
elfctl is a tool for modifying the NT_FREEBSD_FEATURE_CTL ELF note,
which contains a set of flags for enabling or disabling vulnerability
mitigations and other features.

Reviewed by:	csjp, kib
MFC after:	2 weeks
Relnotes:	Yes
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D23910
2020-03-02 02:36:41 +00:00