Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

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

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

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

If the IdlePDPT is not present, PAE is not active

libkvm code janitoring

- make WARNS=6 clean for archs w/o strict alignment requirments
- add const, ANSIfy, remove unused vars, cast types for comparison
- thanks to differing definitions of VM_MIN_ADDRESS across our archs, we
need to trick the compiler to not complain about signedness. We could
either fix VM_MIN_ADDRESS to always be a simple integer or make the
check conditional on $ARCH.

Closes PRs: kern/42386, kern/83364
Reviewed by: bde

Fix a copy-paste bug when reading data from the last 3 (7 for PAE) bytes of
a page mapped by a large page in the kernel.

Submitted by: Dorr H. Clark dclark of engr.scu.edu
MFC after: 1 week

Fix missing includes of <string.h>, to silence some compiler warnings.

Submitted by: Pawel Worach

Re-enable raw dump format support on i386 and amd64 for /dev/fwmem.

Remove the advertising clause. UCB did this some time ago, but these
files were never updated to reflect that.

MFC After: 2 days

Teach libkvm how to read minidumps. It turns out that minidumps are
far more convenient for libkvm to work with because of the page table
block at the beginning. As a result, the MD code is smaller.

libkvm will automatically detect old vs mini dumps on i386 and amd64.

libkvm will handle i386 PAE and non-PAE modes. There is a PAE flag in
the i386 minidump header to signal the width of the entries in the
page table block.

Other convenient values are also present, such as kernbase and the direct
map addresses on amd64.

Fix a well duplicated fencepost error that stopped crashdumps being
readable on certain random memory configurations. If the libkvm consumer
tried to read something that was in the very last pdpe, pde or pte slot,
it would bogusly fail.

This is broken in RELENG_6 too.

Match _kvm_kvatop to it's prototype in kvm_i386.c. This unbreaks
the build.

Approved by: re

Support crash dumps > 4GB in size on 32 bit platforms. _kvm_kvatop()
returned an lseek offset in a "u_long *" value, which can't express >4GB
offsets on 32 bit machines (eg: PAE). Change to "off_t *" for all.

Support ELF crashdumps on i386 and amd64.

Support PAE crashdumps on i386. This is done by auto-detecting the
presence of the IdlePDPT which means that PAE is active.

I used Marcel's _kvm_pa2off strategy and ELF header reader for ELF support
on amd64. Paul Saab ported the amd64 changes to i386 and we implemented
the PAE support from there.

Note that gdb6 in the src tree uses whatever libkvm supports. If you want
to debug an old crash dump, you might want to keep an old libkvm.so handy
and use LD_PRELOAD or the like. This does not detect the old raw dump
format.

Approved by: re

Compensate for "Compensate for header dethreading" by backing it out.

Implement __FBSDID()

Dynamically adjust to the value of KERNBASE in a crashdump, with
a fallback for old kernels without the "kernbase" symbol.

Compensate for header dethreading.

Use kldsym(2) to lookup symbol values. This avoids the kvm_mkdb juggling
and is module aware. Yes, this means that kvm_nlist(3) will find symbols
in loaded modules. The emulation of the nlist struct is pretty crude but
seems to work well enough for all the users in the tree that I found.

Copy code from gnu/usr.bin/gdb/gdb/kvm-fbsd.c to deal with 4 MB pages.

Implement virtual-to-physical address mapping for the kvm library on
dead kernel debugging. The previous code was a "do nothing".

The most obvious side effect of this is that you can now do things like
this and reasonably expect them to work:
dmesg -M /var/crash/vmcore.3 -N /var/crash/kernel.3
ps -axl -M /var/crash/vmcore.3 -N /var/crash/kernel.3

A good deal of this was lifted from the gdb code to do this, as well as
from NetBSD's libkvm (which has completely different VM macros)

General -Wall warning cleanup, part I.
Submitted-By: Kent Vander Velden <graphix@iastate.edu>

NBPG -> PAGE_SIZE

Remove trailing whitespace.

A semicolon was lost.

From: "gj%pcs.dec.com@inet-gw-1.pa.dec.com" <garyj@rks32.pcs.dec.com>
Given the right circumstances, a call to kvm_open can result in a core
dump.

The diff belows fixes this (note that this change is already in the
NetBSD code). Could somebody apply this?

Gary J.
Submitted by: gj

Made kvm routines use procfs to get out process data such as argument
strings.

Fix kvm_i386.c just enough to make it compile and return lots of errors
when called. Noop out swapread in kvm_proc.c as our vm system is
different.

This is a COPY of kvm_hp300.c, soon to be patched to sorta work with
the i386 port.