They are used when ASLR is not applied.
The need for adjusting is due to rtld direct exec mode puts ld-elf.so.1
at the PIE load address, and this address must not conflict with the
default linker' load address for non-PIE binaries. Otherwise rtld in
direct mode cannot activate image. Example of implicit failure is ldd(1)
refusing to run.
Reported by: kp
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D37085
FreeBSD exports CPU features as bits in the AT_HWCAP and AT_HWCAP2
vectors via elf_aux_info(3). This interface is similar to getauxval(3)
on Linux, and for simplicity to consumers we try to maintain an
identical set of feature flags on arm64.
The first batch of AT_HWCAP flags were added in r350166, corresponding
to definitions that already existed in Linux. Unfortunately, one flag
was missed, and a portion of the values are shifted one bit to the right
as a result.
Add the missing definition for HWCAP_ASIMDHP, and adjust the affected
values to match their Linux counterparts.
Although this is an ABI-breaking change, there is no plan to provide
compat code for old binaries. An audit of our ports tree and other
software via Debian code search indicates that there are not yet any
consumers of this interface for FreeBSD/arm64.
Bump __FreeBSD_version to be on the safe side, in case compat code needs
to be added in the future.
Reviewed by: emaste, manu
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D26329
This is in sync with what is defined for Linux 5.8. Note that all bits
in HWCAP are exhausted, and HWCAP2 has been added.
This also revealed an error in some of the existing definitions. We are
missing HWCAP_ASIMDHP, and as a result a portion of the HWCAP values are
shifted right by one bit. This will be fixed in an upcoming change, but
the values being added now are compatible with what Linux defines.
Reviewed by: emaste, markj, manu
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D26030
Summary: Add trivial 32-bit arm cores on aarch64 support for gcore. This
doesn't handle fpregs.
Reviewed by: #arm, andrew
Sponsored by: Juniper Networks, Inc
Differential Revision: https://reviews.freebsd.org/D21947
Add HWCAP support for arm64.
defines are the same as in Linux and a userland program can use
elf_aux_info to get the data.
We only save the common denominator for all cores in case the
big and little cluster have different support (this is known to
exists even if we don't support those SoCs in FreeBSD)
Differential Revision: https://reviews.freebsd.org/D17137
All platforms except powerpc use the same values and powerpc shares a
majority of them.
Go ahead and declare AT_NOTELF, AT_UID, and AT_EUID in favor of the
unused AT_DCACHEBSIZE, AT_ICACHEBSIZE, and AT_UCACHEBSIZE for powerpc.
Reviewed by: jhb, imp
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D17397
Right now I'm using two Raspberry Pi's (2 and 3) to test CloudABI
support for armv6, armv7 and aarch64. It would be nice if I could
restrict this to just a single instance when testing smaller changes.
This is why I'd like to get COMPAT_CLOUDABI32 to work on arm64.
As COMPAT_CLOUDABI32 depends on COMPAT_FREEBSD32, at least for the ELF
loading, this change adds all of the bits necessary to at least build a
kernel with COMPAT_FREEBSD32. All of the machine dependent system calls
are still stubbed out, for the reason that implementations for these are
only useful if actual support for running FreeBSD binaries is added.
This is outside the scope of this work.
Reviewed by: andrew
Differential Revision: https://reviews.freebsd.org/D13144
- allocate value for new AT_HWCAP2 auxiliary vector on all platforms.
- expand 'struct sysentvec' by new 'u_long *sv_hwcap2', in exactly
same way as for AT_HWCAP.
MFC after: 1 month
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D12699
A new 'u_long *sv_hwcap' field is added to 'struct sysentvec'. A
process ABI can set this field to point to a value holding a mask of
architecture-specific CPU feature flags. If an ABI does not wish to
supply AT_HWCAP to processes the field can be left as NULL.
The support code for AT_EHDRFLAGS was already present on all systems,
just the #define was not present. This is a step towards unifying the
AT_* constants across platforms.
Reviewed by: kib
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D12290
