Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

MFC r233231:
Fix several problems with our ELF filters implementation.

Do not relocate twice an object which happens to be needed by loaded
binary (or dso) and some filtee opened due to symbol resolution when
relocating need objects. Record the state of the relocation
processing in Obj_Entry and short-circuit relocate_objects() if
current object already processed.

Do not call constructors for filtees loaded during the early
relocation processing before image is initialized enough to run
user-provided code. Filtees are loaded using dlopen_object(), which
normally performs relocation and initialization. If filtee is
lazy-loaded during the relocation of dso needed by the main object,
dlopen_object() runs too earlier, when most runtime services are not
yet ready.

Postpone the constructors call to the time when main binary and
depended libraries constructors are run, passing the new flag
RTLD_LO_EARLY to dlopen_object(). Symbol lookups callers inform
symlook_* functions about early stage of initialization with
SYMLOOK_EARLY. Pass flags through all functions participating in
object relocation.

Use the opportunity and fix flags argument to find_symdef() in
arch-specific reloc.c to use proper name SYMLOOK_IN_PLT instead of
true, which happen to have the same numeric value.

MFC r233777 (by kan):
Do not try to adjust stacks if dlopen_object is called too early.

MFC r233778 (by kan):
Remove extra blank line from revious commit.

MFC note: the ARM and MIPS TLS support is not merged back, so the chunks
from r233231 which fix misuse of flags in calls to find_symdef() in
the corresponding relocation type handlers were not applied. When TLS
support is merged, the rest of r233231 should be applied too.

MFC r232831:
Add support for preinit, init and fini arrays to rtld.
Only binaries marked with proper ABI note gets array ctr/dtrs called.

MFC r232856:
When iterating over the dso program headers, the object is not initialized
yet, and object segments are not yet mapped. Only parse the notes that
appear in the first page of the dso (as it should be anyway), and use
the preloaded page content.

MFC r232857 (by dim):
Fix a warning/error with clang.

MFC r232859 (by dim):
Amend r232857, now dropping the casts entirely, as they were not
necessary at all.

MFC r228435:
Add support for STT_GNU_IFUNC and R_MACHINE_IRELATIVE GNU extensions to
rtld on 386 and amd64.

MFC r228503:
Postpone the resolution for irelative/ifunc right before initializers
are called, and drop bind lock around calls to dispatcher. Use
initlist to iterate over the objects instead of the ->next, due to
drop of the bind lock in iteration.

For i386/reloc.c:reloc_iresolve(), fix calculation of the dispatch
function address for dso, by taking into account possible non-zero
relocbase.

MFC r228635 (by nwhitehorn):
Fix RTLD on PowerPC after r228435. Changing the order of init_pltgot()
caused the icache to be invalidated at the wrong time, resulting in
an icache full of nonsense in the PLT section.

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

When loading dso without PT_GNU_STACK phdr, only call
__pthread_map_stacks_exec() on architectures that allow executable
stacks.

Reported and tested by: marcel (ia64)

Implement support for ELF filters in rtld. Both normal and auxillary
filters are implemented.

Filtees are loaded on demand, unless LD_LOADFLTR environment variable
is set or -z loadfltr was specified during the linking. This forces
rtld to upgrade read-locked rtld_bind_lock to write lock when it
encounters an object with filter during symbol lookup.

Consolidate common arguments of the symbol lookup functions in the
SymLook structure. Track the state of the rtld locks in the
RtldLockState structure. Pass local RtldLockState through the rtld
symbol lookup calls to allow lock upgrades.

Reviewed by: kan
Tested by: Mykola Dzham <i levsha me>, nwhitehorn (powerpc)

Add parentheses around the argument 'x' used in the __bswapXX(x) macros. Revert
r211130 in favor of this more general fix.

This fixes a compilation error for mips 64-bit little endian build.
libexec/rtld-elf/mips/reloc.c:196: warning: right shift count >= width of type

Suggested by: stefanf, jchandra, bde

Fix compilation error for 64-bit little endian build:
libexec/rtld-elf/mips/reloc.c:196: warning: right shift count >= width of type

When the expression '(r_info) >> 32' was passed to bswap32() it was promptly
changed to '(uint32_t)(r_info) >> 32' which is not what we intended.

64 bit support for MIPS rtld.

- Handle the case where pltgot[1] is 64 bit.
- use 'ifdef __mips_n64' instead of 'ELFSIZE == 64' to detect 64 bit compile.

Merge jmallett@'s n64 work into HEAD - changeset 3

Update rtld MIPS code to use assembly macros that work on o32/n64.

Changes from http://svn.freebsd.org/base/user/jmallett/octeon

Approved by: rrs(mentor), jmallett

Updated rtld for n32 support.

Submitted by: jmallet@
Obtained from: NetBSD

Now that the kernel defines CACHE_LINE_SIZE in machine/param.h, use
that definition in the custom locking code for the run-time linker
rather than local definitions.

Pointed out by: tinderbox
MFC after: 2 weeks

This code has no copyright. It is fairly obvious to me that we're a
derivitive of NetBSD's mips_reloc.c, so pull in the copyright notice
from there.

Also, a minor tweak to load/store pointers. Other changes from NetBSD
likely would be useful too...

Obtained from: NetBSD

MFp4: Fix a bug in the mips relocation code that prevents shared images
from working.

From p4 filelog of the upstream file in p4

//depot/projects/mips2-jnpr/src/libexec/rtld-elf/mips/reloc.c
... #6 change 140737 edit on 2008/04/27 by gonzo@gonzo_jeeves (text+ko)

o Looks like handler for R_MIPS_REL32 brought by CS 137942
is broken for tradmips. Code from NetBSD's
libexec/ld.elf_so/arch/mips/mips_reloc.c works just fine.

... #3 change 137942 edit on 2008/03/17 by rrs@rrs-mips2-jnpr (text+ko)

Any relocation symbol lookup if its 0. It looks like
this is the way the compiler indicates you need to
look in another shared library. When we hit these
as we relocate a object we will do the symbol
lookups and setup the relocation table with the
right value.

Submitted by: rrs@, gonzo@

MFp4: Add mips support for dynamic linking.

This code came from the merged mips2 and Juniper mips repositories.
Warner Losh, Randall Seager, Oleksandr Tymoshenko and Olivier Houchard
worked to merge, debug and integrate this code. This code may also
contain code derived from NetBSD.