Remove $FreeBSD$: two-line .h pattern

Remove /^\s*\*\n \*\s+\$FreeBSD\$$\n/

rtld: Add a stop indicator to rtld_start to satisfy unwinders on x86_64

The right unwinding stop indicator should be CFI-undefined PC.
https://dwarfstd.org/doc/Dwarf3.pdf - page 118:
If a Return Add

rtld: Add a stop indicator to rtld_start to satisfy unwinders on x86_64

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.

That is allows gdb and libunwind successfully stop when unwinding stack
from global constructors and destructors.

Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D40794

show more ...

Remove $FreeBSD$: two-line .h pattern

Remove /^\s*\*\n \*\s+\$FreeBSD\$$\n/

rtld: Add a stop indicator to rtld_start to satisfy unwinders on x86_64

The right unwinding stop indicator should be CFI-undefined PC.
https://dwarfstd.org/doc/Dwarf3.pdf - page 118:
If a Return Add

rtld: Add a stop indicator to rtld_start to satisfy unwinders on x86_64

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.

That is allows gdb and libunwind successfully stop when unwinding stack
from global constructors and destructors.

Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D40794

show more ...

Merge ^/head r312207 through r312308.

MFhead@r312305

rtld: do not rely on a populated GOT on amd64

On rela architectures GNU BFD ld and gold store the relocation addend
in GOT entries (in addition to the relocation's r_addend field).
rtld previously r

rtld: do not rely on a populated GOT on amd64

On rela architectures GNU BFD ld and gold store the relocation addend
in GOT entries (in addition to the relocation's r_addend field).
rtld previously relied on this to access its own _DYNAMIC symbol in
order to apply its own relocations.

However, recording addends in the GOT is not specified by the ABI,
and some versions of LLVM's LLD linker leave the GOT uninitialized on
rela architectures.

BFD ld does not populate the GOT on sparc64, and sparc64 rtld has a
machine-dependent rtld_dynamic_addr() function that returns the
_DYNAMIC address. Use the same approach on amd64, obtaining the %rip-
relative _DYNAMIC address following a suggestion from Rafael Espíndola.

Architectures other than amd64 should be addressed in future work.

PR: 214972
Reviewed by: kib
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D9180

show more ...

Catch up with HEAD (r280229-r284686).

Merge sync of head

MFH: r280643-r281852

Sponsored by: The FreeBSD Foundation

Merge from HEAD

Change compiler setting to make default visibility of the symbols for
rtld on x86 to be hidden. This is a micro-optimization, which allows
intrinsic references inside rtld to be handled without indi

Change compiler setting to make default visibility of the symbols for
rtld on x86 to be hidden. This is a micro-optimization, which allows
intrinsic references inside rtld to be handled without indirection
through PLT. The visibility of rtld symbols for other objects in the
symbol namespace is controlled by a version script.

Reviewed by: kan, jilles
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks

show more ...

MFC @ r266724

An SVM update will follow this.

Merge head

IFC @264767

Add dwarf annotations to the amd64 _rtld_bind_start to allow debuggers
to unwind around the calls from PLT to binder.

Sponsored by: The FreeBSD Foundation
MFC after: 1 week

IFC @230489 (pending review).

IFC @ r226824

Merge ^/head r312207 through r312308.

MFhead@r312305

rtld: do not rely on a populated GOT on amd64

On rela architectures GNU BFD ld and gold store the relocation addend
in GOT entries (in addition to the relocation's r_addend field).
rtld previously r

rtld: do not rely on a populated GOT on amd64

On rela architectures GNU BFD ld and gold store the relocation addend
in GOT entries (in addition to the relocation's r_addend field).
rtld previously relied on this to access its own _DYNAMIC symbol in
order to apply its own relocations.

However, recording addends in the GOT is not specified by the ABI,
and some versions of LLVM's LLD linker leave the GOT uninitialized on
rela architectures.

BFD ld does not populate the GOT on sparc64, and sparc64 rtld has a
machine-dependent rtld_dynamic_addr() function that returns the
_DYNAMIC address. Use the same approach on amd64, obtaining the %rip-
relative _DYNAMIC address following a suggestion from Rafael Espíndola.

Architectures other than amd64 should be addressed in future work.

PR: 214972
Reviewed by: kib
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D9180

show more ...

Catch up with HEAD (r280229-r284686).

Merge sync of head

MFH: r280643-r281852

Sponsored by: The FreeBSD Foundation

Merge from HEAD