Rework ifunc support to address a number of short comings:
- Move to a shared _rtld_call_ifunc for rel and rela architectures
- Architectures using rel format must patch IRELATIVE non-PLT
relocations like RELATIVE in additition to the later ifunc handling
- Consistently record the delta to the end of the relocation group for
non-PLT IRELATIVE relocations

Hidden ifunc is now supported on all ifunc platforms, even when using
-fno-plt. The combination of -fno-plt and relro is broken due to
incorrect GNU ld output though.

branches: 1.7.82;
Explicitly prefix ld(1) options in LDFLAGS with "-Wl," rather than
using the ${LDFLAGS:@F@-Wl,$F@} make substitution because that breaks
if LDFLAGS is already set.

Move common LDFLAGS into Makefile from arch/*/Makefile.inc

Whitespace.

Implement self-relocation as is required now.

branches: 1.3.2;
Grumble. Put compiler options back into CPPFLAGS for now, since
they're needed to build .S files with the correct PIC options.

XXX Really needs cleanup in <bsd.*.mk> to do this properly.

Don't put compiler options into CPPFLAGS.

Preliminary x86-64 support. Not fully functional yet (toolchain bugs).

ld.elf_so/arch/x86_64: Add reference to amd64 psABI.

ld.elf_so(1): Nix trailing whitespace.

No functional change intended.

branches: 1.48.2;
Fix interactions of initial-exec TLS model and dlopen

(1) If an initial-exec relocation was used for a non-local symbol
(i.e. the definition of the symbol is in a different DSO), the
computation of the static TLS offset used the wrong DSO.
This would effectively mean the wrong address was computed
(PR toolchain/50277, PR pkg/57445).

Fix this by forcing the computation of the correct DSO (the one defining
the symbol).

This code uses __UNCONST to avoid the vast interface changes for this
special case.

(2) If symbols from a DSO loaded via dlopen are used with both
global-dynamic/local-dynamic and initial-exec relocations AND
a initial-exec relocation was resolved first in a thread, a split brain
situation could exist where the dynamic relocations would use one memory
block (separate allocation) and the initial-exec relocations the static
per-thread TLS space.

(3) If the initial-exec relocation in (2) is seen after any thread has
already used a GD/LD allocation, bail out. Since IE relocations are used
only in the GOT, this will prevent the dlopen. This is a bit more
aggressive than necessary, but a full blown reference counting doesn't
seem to be justified.

branches: 1.47.4; 1.47.12;
Rework ifunc support to address a number of short comings:
- Move to a shared _rtld_call_ifunc for rel and rela architectures
- Architectures using rel format must patch IRELATIVE non-PLT
relocations like RELATIVE in additition to the later ifunc handling
- Consistently record the delta to the end of the relocation group for
non-PLT IRELATIVE relocations

Hidden ifunc is now supported on all ifunc platforms, even when using
-fno-plt. The combination of -fno-plt and relro is broken due to
incorrect GNU ld output though.

branches: 1.46.2;
init/fini for the main program is handled by crt0.o, so ifunc handling
is skipped right now as it iterates the same list. Don't repeat that
mistake and explicitly take care of it in the dynamic linker.

Add IRELATIVE support for ARM, X86 and PowerPC.

rename the macro

make this compile with debug again (symnum uninitialized)

Replace COMBREL with just-in-time check in _rtld_relocate_nonplt_objects.

The COMBREL logic predates thread-safety of the dynamic linker and
breaks the use of shared locks for the common symbol lookup case. It is
unlikely to provide any benefit for lazy binding or PLT lookups, so
provide equivalent functionality in the non-PLT relocation handling loop
by checking if the symbol used by the current relocation is the same as
the one used during the last lookup. No inter-object cachine is done as
it is also unlikely to be benefical.

Testing with Firefox startup on AMD64 shows a small performance gain by
the new method.

branches: 1.41.8;
Add basic support for indirect functions. It allows providing a public
function symbol with an implementation choosen at run time.
Refactor calls to functions by address in ld.elf_so to create temporary
function descriptors on the stack, if the address is not leaked outside.

Limitations:
- no support for initialising static storage with function pointers
- no support for unnamed resolver functions

Inspired by FreeBSD's r228435 by kib@freebsd.org.

branches: 1.40.22;
Add basic locking to ld.elf_so.

Add TLS support for AMD64, i386 and SH3.

This material is based upon work partially supported by
The NetBSD Foundation under a contract with Joerg Sonnenberger.

Reduce header pollution for mdreloc.c. Make Obj_Entry argument of
_rtld_relocate_nonplt_objects non-const in preparation for TLS support.

Make DEBUG build compile.

PR/39240: Satoshi Suetake: Don't fail when attempting to resolve weak symbols
when we are doing immediate binding, leave them alone and they will be dealt
with later during lazy binding. From skrll@

Remove trailing \n in calls to _rtld_error: a newline is automatically
added by a call to the function.

Fix const issues (cast const pointers to "const uint8_t *" instead of "caddr_t")

rename a variable to avoid a compiler warning

branches: 1.32.4; 1.32.6;
Refactor common code to _rtld_relocate_plt_object to i386 and arm so they
act like the other versions.
In _rtld_bind, if the result is 0, call _rtld_die.
Initialize _rtld_sym_zero.st_value to -_rtld_objself.maprelocbase. Now when
the symbol is resolved, st_value + maprelocbase will equal 0 and the above
check in _rtld_bind will fire and a call to NULL will be avoided.

abort() if we are trying to use an undefined weak symbol from the plt. Remove
check from relocate_plt_object() since we cannot return _rtld_sym_zero anymore.
Code from gimpy.

deal specially with sym_zero, returned by a weak symbol that was not found,
by retrieving it's name instead of printing random garbage.

branches: 1.29.12;
Remove MD COMBRELOC support since it's now MI.
Enable COMBRELOC for all arches

Provide COMBRELOC support for amd64 in answer to PR/35589.

Some statistics:

base + COMBRELOC
$ time (for i in `seq 100`;do noatun --help>/dev/null;done)
(; for i in `seq 100`; do; noatun --help > /dev/null; done; ) 148.64s
user 4.82s system 99% cpu 2:33.93 total

base + DF caching:
$ time (for i in `seq 100`;do noatun --help>/dev/null;done)
(; for i in `seq 100`; do; noatun --help > /dev/null; done; ) 151.15s
user 5.53s system 99% cpu 2:37.23 total

base:
$ time (for i in `seq 100`;do noatun --help>/dev/null;done)
(; for i in `seq 100`; do; noatun --help > /dev/null; done; ) 492.36s user
5.34s system 99% cpu 8:19.17 total

appease gcc4 uninitialiased warning
ok mrg.

Add __RCSID.

KNF

Support immediate binding on x86_64.

Closes PR 30570. Thanks to TAMURA Kent for testing.

ANSIfy and de-__P().

Replace return -1 in rtld_bind with _rtld_die() call.

Implement self-relocation as is required now.

Skip the lazy PLT relocation if relocbase==0 (useful if libraries are loaded
at their VMA address).

Remove the `self' args to _rtld_relocate_objects() and
_rtld_relocate_nonplt_objects().

Partly fix this port -- still needs a self-reloc function.

Nuke -DRTLD_RELOCATE_SELF and `dodebug' from orbit.

_rtld_bind_start() is not used in MI code, so declare it in the MD code.

Pass down an additional flag to _rtld_relocate_nonplt_objects() which
indicates whether we're relocating ld.elf_so itself. Use this in some places
rather than hackish tests on `dodebug'. (The Alpha and HPPA `dodebug' tests
were actually noops, because RTLD_RELOCATE_SELF is not set, and therefore
dodebug is always true.)

Introduce a new flag, `isdynamic', which is used to remember whether the
executable was of type ET_DYN. Use this instead of `mainprog' to determine
whether we need to do base-relative fixups of the PLT. (This allows loading
non-relocatable objects, should we desire to do that at some point...)

Re-poison a lot of consts, now that the mark shite is gone.

Split _rtld_relocate_plt_object() into two MD functions:
* _rtld_relocate_plt_lazy() fixes up all the relocs pointing to the PLT. (On
most platforms it just does a simple base-relative fixup; on SPARC it does
nothing.)
* _rtld_relocate_plt_object() does immediate binding for a PLT entry.
The basic gist is that this saves a bit of time on SPARC (where the iteration
through the pltrela table was gratuitous), and a little less time on all other
platforms. A whole lot of #ifdef'ed crap is moved out of reloc.c, too.

NOT tested on: hppa sh x86_64

Partially fix up some debug printf()s that don't need to use defobj.

A few things:
* Pass a symbol number to _rtld_find_symdef(), not a r_info.
* Don't try to do a symbol lookup when we find an unsupported relocation;
instead get the symbol name from the referencing object's strtab.
* Add preliminary support for `-z combreloc'-style startup optimization on
i386, `#ifdef COMBRELOC'.

Rename _rtld_relocate_nonplt_object() to _rtld_relocate_nonplt_objects(),
and push the outer loop into it. This actually shaves a couple % off startup
time at least on PCs.

Split _rtld_relocate_nonplt_object() into separate MD files.

Remove unused arguments of _rtld_find_symdef().

Make _rtld_setup_pltgot() a consistent interface on all platforms.

branches: 1.5.2;
...and the other other missing notice.

Add other missing copyright notice.

Remove mistaken casts of PLT relocations to 32 bit values.

Adapt for an actually correct sys/exec_elf.h

Preliminary x86-64 support. Not fully functional yet (toolchain bugs).

Align in the stack before calling _rtld in the way the x86_64 ABI
specifies. This is necessary to ensure that init functions are always
called with the correct alignment, e.g. in case they use SSE
instructions.

branches: 1.8.6;
Build ld.elf_so with -fvisibility=hidden. Exploit this for i386/x86_64
to simplify the assembler code.

Add comment about the unusual stack alignment in .rtld_bind_start.

Eliminate GOT usage in rtld_start() on this platform, too.

Implement self-relocation as is required now.

Partly fix this port -- still needs a self-reloc function.

branches: 1.3.2;
Add missing copyright notice.

Get stack layout right.

Preliminary x86-64 support. Not fully functional yet (toolchain bugs).