Use the Global Offset Table to find the location of main in crt1. With
lld the old code would point to main@plt, however ld.bfd fails to link
when main is in a shared library.
Fix this by using the GOT address to find main as it works with both
lld and bfd.
Reviewed by: jrtc27
Sponsored by: Arm Ltd
Differential Revision: https://reviews.freebsd.org/D45259
Add the Branch Target Identification (BTI) note to libc assembly
sources and Pointer Authentication Code (PAC) instructions to _init and
_fini.
_init and _fini may be called indirectly so need a BTI landing pad. As
they are non-leaf functions use the appropriate PAC instruction that
also guards against changing the link register.
As all object files need the note for any binary using these object files
we need to insert it in all asm files.
Reviewed by: markj
Sponsored by: Arm Ltd
Differential Revision: https://reviews.freebsd.org/D42227
The right unwinding stop indicator should be CFI-undefined PC.
https://dwarfstd.org/doc/Dwarf3.pdf - page 118:
If a Return Address register is defined in the virtual unwind table,
and its rule is undefined (for example, by DW_CFA_undefined), then
there is no return address and no call address, and the virtual
unwind of stack activations is complete.
Reviewed by:
Differential Revision: https://reviews.freebsd.org/D40623
Normally, modern unwinders uses Dwarf information to unwind stack,
however in case when the code is not annotated by Dwarf instructions,
unwinders fallbacks to a frame-pointer based algorithm.
That is allows libunwind to unwind stack from global constructors and
destructors. Also it makes gdb happy as it printed nonexistent frame
before.
Reviewed by:
Differential Revision: https://reviews.freebsd.org/D40842
Why? Most trivial point, it shaves around 600 bytes from the dynamic
binaries on amd64. Less trivial, the removed code is no longer part of
the ABI, and we can ship updates to it with libc updates. Right now most
of the csu is linked into the binaries and require us to do somewhat
tricky ABI compat when it needs to change. For instance, the init_array
change would be much simpler and does not require note tagging if we
have init calling code in libc.
This could be improved more, by splitting dynamic and static
initialization. For instance, &_DYNAMIC tests can be removed then.
Such change, nonetheless, would require building libc three times.
I left this for later, after this change stabilizes, if ever.
Reviewed by: markj
Discussed with: jrtc27 (some objections, see the review), imp
Tested by: markj (aarch64)
Sponsored by: The FreeBSD Foundation
MFC after: 3 weeks
Differential revision: https://reviews.freebsd.org/D37220
Add support for the R_AARCH64_IRELATIVE relocation type in static
binaries on arm64. This is based on the powerpc code, updating it to
use the arm64 resolver ABI, and use the arm64 relocation type.
Tested by: brd
Reviewed by: kib
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D31641
The ELF notes compiled in C were placed in a section with the wrong type
(SHT_PROGBITS instead of SHT_NOTE). Previously, sed was used on the
generated assembly to rewrite the section type. Instead, write the notes
in assembly which permits setting the correct section type directly.
While here, move inline assembly entry points out of C and into assembly
for aarch64, arm, and riscv.
Reviewed by: kib
Tested on: amd64 (cirrus-ci), riscv64
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D25211
These are needed for .ctors/.dtors and .jcr handling. The former needs
all the function pointers to be called in the correct order from the
.init/.fini section. The latter just needs to call a gcj specific function
if it exists with a pointer to the start of the .jcr section.
This is currently disabled until __dso_handle support is added.
Reviewed by: emaste
MFC after: 1 month
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D17587
This makes statically linked binaries with ifuncs operational.
Reported and tested by: mjg
Reviewed by: emaste, markj
Sponsored by: The FreeBSD Foundation
Approved by: re (rgrimes)
Differential revision: https://reviews.freebsd.org/D17363
On most architectures crt objects are compiled in a multiple-step process
so that sed can be run on the generated assembly. As the final step,
the C compiler generates an object file from the modified assembly output.
Currently this last step uses $CC with only $ACFLAGS. However, for other
uses in the tree, $ACFLAGS is meant to include assembly-specific compiler
flags that are in addition to $CFLAGS (see default .S.o rules
bsd.suffixes.mk). In particular, external toolchains may require
additional flags to select a non-default target which will be present
in CFLAGS but not ACFLAGS. To support this while still mitigating the
issue with CFLAGS described in r234502, include a modified CFLAGS that
excludes "-g" when assembling the modified assembly files.
Note that normally an assembler ($AS) is used to assemble .s flags to
object files (see bsd.suffixes.mk). However, llvm-based toolchains do
not currently have a stand-alone assembler.
Reviewed by: imp
Sponsored by: DARPA / AFRL
Differential Revision: https://reviews.freebsd.org/D10085
stackpointer. Userland expects the kernel to pass it an aligned sp and
pass a pointer to the arguments in x0. The kernel side was updated in
r289502, 3 months ago.
Sponsored by: ABT Systems Ltd
The requirement is for a GCC-compatible compiler and not necessarily
GCC itself. However, we currently expect any compiler used for building
the whole of FreeBSD to be GCC-compatible and many things will break if
not; there's no longer a need to have an explicit test for this in csu.
Sponsored by: The FreeBSD Foundation
FILES is not used when LIBRARIES_ONLY is set, which is used to build and
install the lib32 sysroot. All of the csu files do quality as "libraries"
for this case so just undefine LIBRARIES_ONLY.
This is still better than the previous realinstall handling as it does
not hook into META_MODE properly.
Sponsored by: EMC / Isilon Storage Division
This partially reverts r270170 for lib/csu/i386 while retaining the
change for using bsd.lib.mk.
These FILES groups could go into lib/csu/Makefile.inc but I've kept them
in the Makefiles for clarity.
Sponsored by: EMC / Isilon Storage Division
When enough time has passed for users to update their userland the kernel
fix will be applied. This will change the ABI to have x0 point to the args
and sp be correctly aligned.
It is expected this compatibility code can be removed when the kernel and
qemu usermode emulation have both been updated for the new ABI.
This fixes clang failures, and most likely other crashes.
Obtained from: ABT Systems Ltd
Sponsored by: The FreeBSD Foundation
only adds support for kernel-toolchain, however it is expected further
changes to add kernel and userland support will be committed as they are
reviewed.
As our copy of binutils is too old the devel/aarch64-binutils port needs
to be installed to pull in a linker.
To build either TARGET needs to be set to arm64, or TARGET_ARCH set to
aarch64. The latter is set so uname -p will return aarch64 as existing
third party software expects this.
Differential Revision: https://reviews.freebsd.org/D2005
Relnotes: Yes
Sponsored by: The FreeBSD Foundation
