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 r237430:
Reserve AT_TIMEKEEP auxv entry for providing usermode the pointer to
timekeeping information.

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

Approved by: re (implicit)

Add AT_STACKPROT elf aux vector. Will be used to inform rtld about the
initial stack protection set by the kernel image activator.

Supply some useful information to the started image using ELF aux vectors.
In particular, provide pagesize and pagesizes array, the canary value
for SSP use, number of host CPUs and osreldate.

Tested by: marius (sparc64)
MFC after: 1 month

MFppc64:

Provide ELF definitions for 64-bit PowerPC. This unbreaks the powerpc
loader build.

Define architectural load bases for PIE binaries. Addresses were selected
by looking at the bases used for non-relocatable executables by gnu ld(1),
and adjusting it slightly.

Discussed with: bz
Reviewed by: kan
Tested by: bz (i386, amd64), bsam (linux)
MFC after: some time

Add AT_EXECPATH ELF auxinfo entry type. The value's a_ptr is a pointer
to the full path of the image that is being executed.
Increase AT_COUNT.

Remove no longer true comment about types used in Linux ELF binaries,
listed types contain FreeBSD-specific entries.

Reviewed by: kan

AT_DEBUG and AT_BRK were OBE like 10 years ago, so retire them.

Reviewed by: peter

PR:
Submitted by:
Reviewed by:
Approved by:
Obtained from:
MFC after:
Security:
Move the relocation definitions to the common elf header so that DTrace
can use them on one architecture targeted to a different one.

Add the additional ELF types defines in Sun's "Linker and Libraries"
manual.

Implement TLS relocations for powerpc.

Approved by: grehan (mentor)

Add sysentvec->sv_fixlimits() hook so that we can catch cases on 64 bit
systems where the data/stack/etc limits are too big for a 32 bit process.

Move the 5 or so identical instances of ELF_RTLD_ADDR() into imgact_elf.c.

Supply an ia32_fixlimits function. Export the clip/default values to
sysctl under the compat.ia32 heirarchy.

Have mmap(0, ...) respect the current p->p_limits[RLIMIT_DATA].rlim_max
value rather than the sysctl tweakable variable. This allows mmap to
place mappings at sensible locations when limits have been reduced.

Have the imgact_elf.c ld-elf.so.1 placement algorithm use the same
method as mmap(0, ...) now does.

Note that we cannot remove all references to the sysctl tweakable
maxdsiz etc variables because /etc/login.conf specifies a datasize
of 'unlimited'. And that causes exec etc to fail since it can no
longer find space to mmap things.

Move the definition of ElfN_Hashelt to common headers. The only platform
which has a different definition for this is alpha.

Make MAXTSIZ, DFLDSIZ, MAXDSIZ, DFLSSIZ, MAXSSIZ, SGROWSIZ loader
tunable.

Reviewed by: peter
MFC after: 2 weeks

Use a machine dependent type, Elf_Hashelt, for the elements of the elf
dynamic symbol table buckets and chains. The sparc64 toolchain uses 32
bit .hash entries, unlike other 64 bits architectures (alpha), which use
64 bit entries.

Discussed with: dfr, jdp

This commit (along with one pending in sys/dev/ofw and one in sys/conf) give
us our first minimal glimpse of PowerPC support.

With this code we can get to the "mountroot>" prompt on my Apple iMac. We
can't get any further due to lack of clock and interrupt handling, among other
things. This does however mean that pmap and VM are initialising.

We're fairly dependant on OpenFirmware at this point, but I hope to add
support for other classes of firmware at a later stage.

Reviewed by: obrien, dfr

PowerPC specific ELF ABI definitions.