CVS log for src/sys/kern/kern_ksyms.c

Up to [cvs.NetBSD.org] / src / sys / kern

Request diff between arbitrary revisions

Keyword substitution: kv
Default branch: MAIN

s/preudo/pseudo/ in comment.

Pull up following revision(s) (requested by riastradh in ticket #107):

	sys/kern/kern_ksyms.c: revision 1.108

ksyms(4): Reject negative offsets earlier in lseek.

Avoid arithmetic overflow.

ksyms(4): Reject negative offsets earlier in lseek.

Avoid arithmetic overflow.

XXX pullup-10

convert "ksyms: checking <symbol>" into KSYMS_DEBUG over normal DEBUG.

uvm(9): fo_mmap caller guarantees positive size.

No functional change intended, just sprinkling assertions to make it
clearer.

ksymsmmap: Add missing uao_reference(9) call for ks->ks_uobj.

Fix failure for savecore(8) and subsequent kernel panic, introduced to
kern_ksyms.c rev 1.03, at least for sh3 and alpha.

For sh3 and alpha, savecore(8) supports coff and ecoff, respectively, via
libkvm via nlist(3). nlist(3) routines for coff and ecoff use mmap(2) and
munmap(2) for /dev/ksyms.

This munmap(2) decrements reference count for ks->ks_uobj. Unless it is
incremented in ksymsmmap(), ks->ks_uobj will be freed unexpectedly.

ksyms: Use pserialize(9) for kernel access to ksyms.

This makes it available in interrupt context, e.g. for printing
messages with kernel symbol names for return addresses as drm wants
to do.

ksyms(4): Take a complete snapshot on each open.

- Snapshots are stored in pageable anonymous uvm objects.
- Snapshots are reference-counted so they can be reused across opens.
- Opening /dev/ksyms blocks module unload until snapshot is taken.
- Merely holding /dev/ksyms open does not block module unload.
- /dev/ksyms is now mmappable.

This slightly changes the behaviour of fstat(2) on /dev/ksyms -- it
is a little more useful now!  In particular, st_size is the size of
the symbol table.  Some other fields which were not very useful to
begin with -- st_dev, st_ino, st_mode, st_nlink, st_*time,
st_blksize, st_blocks -- are now different, and independent of the
file system on which the device node resides.

Discussed in

https://mail-index.netbsd.org/source-changes-d/2021/08/17/msg013425.html

This is option (3), adapted to make the ksyms snapshots pageable,
after options (1) and (2) posed practical problems.

Revert "ksyms(4): Simply block unload until last /dev/ksyms close."

This appears to break t_execsnoop -- presumably something goes wrong
with how libdtrace uses ksyms.  To investigate.

Revert "ksyms: Use pserialize(9) for kernel access to ksyms."

ksyms: Use pserialize(9) for kernel access to ksyms.

This makes it available in interrupt context, e.g. for printing
messages with kernel symbol names for return addresses as drm wants
to do.

ksyms(4): Simply block unload until last /dev/ksyms close.

Otherwise, readers may get a garbled snapshot of ksyms (or a crash on
an assertion failure because of the garbled snapshot) if modules are
unloaded while they read.

https://mail-index.netbsd.org/source-changes-d/2021/08/17/msg013425.html

Sync with HEAD.

skip symbol tables that were unloaded again to avoid EFAULT when reading
ksyms.

also restore TAILQ_FOREACH idiom.

Pull up following revision(s) (requested by riastradh in ticket #1299):

	sys/kern/kern_ksyms.c: revision 1.90
	sys/kern/kern_ksyms.c: revision 1.91
	sys/kern/kern_ksyms.c: revision 1.92
	sys/kern/kern_ksyms.c: revision 1.93
	sys/kern/kern_ksyms.c: revision 1.94
	sys/kern/kern_ksyms.c: revision 1.95
	sys/kern/kern_ksyms.c: revision 1.96
	sys/kern/kern_ksyms.c: revision 1.97

ksyms(4): Fix ksymsread synchronization.

Fixes crash on concurrent update and read of /dev/ksyms.
XXX Unclear why we have to skip sd_gone entries here -- it seems like
they should be preserved until ksymsclose.
ksyms(4): Modify ksyms_symtabs only at IPL_HIGH.

This limits the opportunities for ddb to witness an inconsistent
state of the symbol table list.
ksyms(4): Don't skip symbol tables that are soon to be freed.

They will not actually be freed until /dev/ksyms is closed, so
continued access to them remains kosher.
Revert "ksyms(4): Don't skip symbol tables that are soon to be freed."

Apparently the equality kassert this restored doesn't work; to be
analyzed.

Fix regression introduced in rev 1.90
in which the last element of ksyms_symtabs is skipped by mistake.

ksyms(4): Fix race in ksymsread iteration.
TAILQ_NEXT(ksyms_last_snapshot) might change while we are iterating,
but ksyms_last_snapshot itself cannot, so invert the loop structure.

Discussed with rin@.

ksyms(4): Don't skip symbol tables that are soon to be freed, take 2.

They will not actually be freed until /dev/ksyms is closed, so
continued access to them remains kosher.
The previous change was busted because of an off-by-one error in a
previous previous change's iteration over the symtabs; that error has
since been corrected.

ksyms(4): Allow multiple concurrent opens of /dev/ksyms.

First one takes a snapshot; others all agree with the snapshot.
Previously this code path was just broken (could fail horribly if
modules were unloaded after one of the opens is closed), so I just
blocked it off in an earlier commit, but that broke crash(8).  So
let's continue allowing multiple opens seeing the same snapshot, but
without the horrible bugs.

Sync w/ HEAD.

sync with head

ksyms(4): Allow multiple concurrent opens of /dev/ksyms.

First one takes a snapshot; others all agree with the snapshot.

Previously this code path was just broken (could fail horribly if
modules were unloaded after one of the opens is closed), so I just
blocked it off in an earlier commit, but that broke crash(8).  So
let's continue allowing multiple opens seeing the same snapshot, but
without the horrible bugs.

ksyms(4): Don't skip symbol tables that are soon to be freed, take 2.

They will not actually be freed until /dev/ksyms is closed, so
continued access to them remains kosher.

The previous change was busted because of an off-by-one error in a
previous previous change's iteration over the symtabs; that error has
since been corrected.

ksyms(4): Fix race in ksymsread iteration.

TAILQ_NEXT(ksyms_last_snapshot) might change while we are iterating,
but ksyms_last_snapshot itself cannot, so invert the loop structure.

Discussed with rin@.

Fix regression introduced in rev 1.90:

http://cvsweb.netbsd.org/bsdweb.cgi/src/sys/kern/kern_ksyms.c#rev1.90

in which the last element of ksyms_symtabs is skipped by mistake.

Revert "ksyms(4): Don't skip symbol tables that are soon to be freed."

Apparently the equality kassert this restored doesn't work; to be
analyzed.

ksyms(4): Don't skip symbol tables that are soon to be freed.

They will not actually be freed until /dev/ksyms is closed, so
continued access to them remains kosher.

ksyms(4): Modify ksyms_symtabs only at IPL_HIGH.

This limits the opportunities for ddb to witness an inconsistent
state of the symbol table list.

ksyms(4): Fix ksymsread synchronization.

Fixes crash on concurrent update and read of /dev/ksyms.

XXX Unclear why we have to skip sd_gone entries here -- it seems like
they should be preserved until ksymsclose.

The current MIPS DDB stacktrace code doesn't work if no symbols are
available, so fall back to old-fashioned unwind code if no symbols.

Merge changes from current as of 20200406

Pull up following revision(s) (requested by pgoyette in ticket #1482):

	sys/kern/kern_ksyms.c: revision 1.88 (patch)

When reading from /dev/ksyms we need to skip over entries that have
been marked as sd_gone.  Otherwise we might try to uiomove() data from
memory that has been unmapped, resulting in EFAULT.

XXX This (along with other pre-existing checks st->sd_gone) is still
racy, but it's an improvement over current code.  Ideally we would
make a complete copy of the symbol table when we open /dev/ksyms so
we could ignore any changes that occur.

ad@ says "good enough for now"

XXX Pullup to -9 and -8

Pull up following revision(s) (requested by pgoyette in ticket #609):

	sys/kern/kern_ksyms.c: revision 1.88

When reading from /dev/ksyms we need to skip over entries that have
been marked as sd_gone.  Otherwise we might try to uiomove() data from
memory that has been unmapped, resulting in EFAULT.

XXX This (along with other pre-existing checks st->sd_gone) is still
racy, but it's an improvement over current code.  Ideally we would
make a complete copy of the symbol table when we open /dev/ksyms so
we could ignore any changes that occur.

ad@ says "good enough for now"

XXX Pullup to -9 and -8

When reading from /dev/ksyms we need to skip over entries that have
been marked as sd_gone.  Otherwise we might try to uiomove() data from
memory that has been unmapped, resulting in EFAULT.

XXX This (along with other pre-existing checks st->sd_gone) is still
racy, but it's an improvement over current code.  Ideally we would
make a complete copy of the symbol table when we open /dev/ksyms so
we could ignore any changes that occur.

ad@ says "good enough for now"

XXX Pullup to -9 and -8

update from HEAD

use Elf_Sym ** instead of casting.

Handle absolute relocations coming from the kernel: preserve SHN_ABS in
the kernel and module symbols, and when relocating a symbol that has
SHN_ABS, take its value as-is and don't return an error if it equals zero.

Sent on tech-kern@.

Sync with HEAD

create an nmap table for module symtabs too.
needed by dtrace.

KNF. Remove extra spaces. No functional change.

Sync with HEAD

Pull up following revision(s) (requested by pgoyette in ticket #1108):
	sys/kern/kern_module.c: revision 1.107-1.110
	sys/kern/kern_ksyms.c: revision 1.82
Add some additional status messages for kern.module.verbose=TRUE

Remove extraneous ')' from previous.

KNF

In module_do_load(), consolidate checking for a pre-existing module,
and return a single error value EEXIST.  When making a recursive
call (to load required modules), treat a pre-existing module as
success.

Without this change, when a module was loaded by specific request
(as opposed to being loaded as a requirement of some other module),
we would always load the module from the file-system, and then
after making various sanity/compatability checks we would destroy
the new copy if there was a pre-existing copy.

Fixes PR kern/40764

XXX Note that if the module exists, we bypass all of the various
XXX "compatability" checks, including whether or not the existing
XXX module is of any particular class!  (In the previous code, we
XXX checked to see if the newly-loaded copy had the correct class,
XXX but not the pre-existing copy, which could have been loaded
XXX from a different path/filename.)

Pull up following revision(s) (requested by pgoyette in ticket #1108):
	sys/kern/kern_module.c: revision 1.107-1.110
	sys/kern/kern_ksyms.c: revision 1.82
Add some additional status messages for kern.module.verbose=TRUE

Remove extraneous ')' from previous.

KNF

In module_do_load(), consolidate checking for a pre-existing module,
and return a single error value EEXIST.  When making a recursive
call (to load required modules), treat a pre-existing module as
success.

Without this change, when a module was loaded by specific request
(as opposed to being loaded as a requirement of some other module),
we would always load the module from the file-system, and then
after making various sanity/compatability checks we would destroy
the new copy if there was a pre-existing copy.

Fixes PR kern/40764

XXX Note that if the module exists, we bypass all of the various
XXX "compatability" checks, including whether or not the existing
XXX module is of any particular class!  (In the previous code, we
XXX checked to see if the newly-loaded copy had the correct class,
XXX but not the pre-existing copy, which could have been loaded
XXX from a different path/filename.)

KSYMS_MAX_ID is too small for i386 kernels built with MKDEBUG=yes,
causing a number of ATF tests to fail.  Increase it by 50%, from 65536
to 98304.

Sync with HEAD (as of 26th Dec)

KNF

Sync with HEAD

Use makeoptions_COPY_SYMTAB via opt_copy_symtab.h in sources.  Remove a hack
to set -DCOPY_SYMTAB from sys/conf/Makefile.kern.inc.  Remove unnecessary
dependencies too.

Constify a little.

we don't need ioconf.h if we don't have the ksyms pseudo-device

If we don't have a pseudo-device, we don't need the attach function.

include ioconf.h instead of locally declaring the prototype of the attach
function

Sync with HEAD

Change the ksyms ioctls to more compat_netbsd32 friendly.  Use _IOWR ioctls
to avoid extra copyouts.  With these changes, netstat and vmstat work on
mips64eb with the normal N32 userland and a N64 kernel.

Sync with HEAD

Don't hard code crap we have perfectly good constants for.

- use the unused section in the array to put a NetBSD note in it
- cleanup the hard-coded constants in the stringtab

Rebase to HEAD as of a few days ago.

Reorganize symbol table embedding.  The existing option SYMTAB_SPACE is
replaced by the make option COPY_SYMTAB set to any value. The copy of
the symbol table is no longer put into a buffer in kern_ksyms.o, but a
small helper object. This object is build first with a dummy size, then
the kernel is linked to compute the real dimension of the symbol table
buffer. After that, the helper object is rebuild and the kernel linked
again.

Rebase.

Add d_discard to all struct cdevsw instances I could find.

All have been set to "nodiscard"; some should get a real implementation.

sync with head.

for a reference, the tree before this commit was tagged
as yamt-pagecache-tag8.

this commit was splitted into small chunks to avoid
a limitation of cvs.  ("Protocol error: too many arguments")

sync with head

Change (mostly mechanically) every cdevsw/bdevsw I can find to use
designated initializers.

I have not built every extant kernel so I have probably broken at
least one build; however I've also found and fixed some wrong
cdevsw/bdevsw entries so even if so I think we come out ahead.

resync from head

don't overwrite the CTF info with the symbol table.

resync with head

sync with head

Add a separate bool to indicate a symbol table has been loaded.
ksym_initted indicates whether the kmutex has been initted or not.
Add __cacheline_aligned to the kmutex.

sync with (a bit old) head

Resync to 2012-11-19 00:00:00 UTC

make ksyms structures not depend on KDTRACE_HOOKS.
always include a CTF section, even though it might be empty.
this fixes savecore's generated kernel symbol table files.

sync with head

merge to -current.

close the comment, there is a draft.

PR/45687: Mike Pumford: savecore: (null): _ksyms_hdr not in namelist
Make it non-static and add a comment so that they don't become static again.

Define SYMTAB_SPACE in opt_ksyms.h, not opt_ddbparam.h.  Ensure
that ddb(4) code is independent of SYMTAB_SPACE value.

These don't need uvm/uvm_extern.h.

Sync with HEAD.

sync with head

- Replace few malloc(9) uses with kmem(9).
- Rename buf_malloc() to buf_alloc(), fix comments.
- Remove some unnecessary inclusions.

sync with head

When determining max/min sym value, ignore ABS symbols which don't
have a type.  This stops ksym thinking that the _KERNEL_OPT symbols
could actually be useful.

Sync with HEAD.

sync with head.

Use 'z' printf format modifier to print size_t in debug code.

sync with head

Some KNF.

DTrace: Fix several bugs where the mod_ctf_get() function could return
success even though no CTF section was present in the kernel or module.
This fixes the panic that several people saw when trying out the FBT
provider without updating /boot or missing a CTF section in /netbsd.

Sync with HEAD.

sync to netbsd-5

DTrace: Make the CTF handling conditional on KDTRACE_HOOKS for now since
it breaks the boot of the atari kernel (and possibly others).

make this compile.

DTrace: Add support for CTF sections in the netbsd elf image, load these
at boot.
Add a ksyms_mod_foreach() function to iterate a callback function over the
set of elf symbols for a specific module (netbsd included).
Add kern_ctf.c and mod_ctf_get() to allow the retrieval and decompression
of CTF sections for a specific module.

sync with head

Revert accidental commit of CTF work-in-progress changes.

DTrace: Add an SDT (Statically Defined Tracing) provider framework, and
implement most of the proc provider.  Adds proc:::create, exec,
exec_success, exec_faillure, signal_send, signal_discard, signal_handle,
lwp_create, lwp_start, lwp_exit.

Pull up following revision(s) (requested by hubertf in ticket #1290):
	sys/kern/kern_ksyms.c: revision 1.53
	sys/dev/pci/agp_via.c: revision 1.18
	sys/netipsec/key.c: revision 1.63
	sys/arch/x86/x86/x86_autoconf.c: revision 1.49
	sys/kern/init_main.c: revision 1.415
	sys/kern/cnmagic.c: revision 1.11
	sys/netipsec/ipsec.c: revision 1.47
	sys/arch/x86/x86/pmap.c: revision 1.100
	sys/netkey/key.c: revision 1.176
Replace more printfs with aprint_normal / aprint_verbose
Makes "boot -z" go mostly silent for me.

Replace more printfs with aprint_normal / aprint_verbose
Makes "boot -z" go mostly silent for me.

Remove highly questionable assert which demans that the kernel symbol
table is in memory at a lower address than the string table.

Sync with HEAD.

Commit is split, to avoid a "too many arguments" protocol error.

sync with head.

Sync with HEAD.

Apply patch (requested by martin in ticket 602):
ksyms_init calls mutex_init too early, which leads to failure on, e.g.,
sparc64 LOCKDEBUG kernels.  Instead, add a new function ksyms_init_finalize
and call it from main.  Fixed in a more intrusive and less ugly way on HEAD.

ansify function definitions

Sync with HEAD.

Initialize SYMTAB_SPACE ksyms during ksyms_init.  Per PR port-evbarm/40311.

Sync with HEAD.

- Fix a CVS merge breakage
- Catch up with some driver changes

Sync with HEAD.

_KERNEL_OPT

Update haad-dm branch to haad-dm-base2.

Make the fake ELF object work with gdb.

- Output a .bss section and make all the symbols relative to it, instead
  of making them absolute.
- Output a single load section, no need for two.

'gdb /dev/ksyms' still doesn't work because ksyms doesn't do mmap yet.

As discussed on tech-kern: mutex_init is too heavyweight for early bootstrap
phases, so move the initialization of the ksyms mutex back into main via
a function called ksyms_init. Rename the existing (but quite different)
ksyms_init* variations into ksyms_addsyms_elf() and ksyms_addsyms_explicit()
and adapt machdep code accordingly.

Our qsort() is inappropriate for kernel use because it makes recursive
calls. Replace it with a kheapsort() function in kernel. Pointed out
by tron@.

Remove unneeded includes.

Fix ksyms_getname() broken in previous.

- Local symbols could shadow globals in some instances. Fix it.

- mutex_enter() from ksyms_getval() could panic due to a change made
  in revision 1.40. Fix it.

- Replace the p-tree with a binary search of global symbols. Saves about
  250kB of wired memory on i386 and allows for faster lookups within
  module symbol tables.

Remove LKMs and switch to the module framework, pass 1.

Proposed on tech-kern@.

don't hold locks in ddb (call ksyms_getval_unlocked()), pointed out by ad.

don't expose ksyms_lock

PR kern/38814 ksyms needs locking

- Make ksyms MT safe.
- Fix deadlock from an operation like "modload foo.lkm < /dev/ksyms".
- Fix uninitialized structure members.
- Reduce memory footprint for loaded modules.
- Export ksyms structures for kernel grovellers like savecore.
- Some KNF.

Sync with HEAD.

RCSID police.

Sync with HEAD.

PR kern/39681 ddb doesn't work with new MODULAR modules

Complete initialization of new symbol table record.

Sync with HEAD.

Sync with wrstuden-revivesa-base-2.

Sync with head.

report local symbols too.

- add "file-system DEVFS" and "pseudo-device devfsctl" to conf/std seeing
  as these are always needed.

- convert many, many drivers over to the New Devfs World Order. For a
  list of device drivers yet to be converted see,
  http://www.netbsd.org/~mjf/devfs-todo.html.

- add a new device_unregister_all(device_t) function to remove all device
  names associated with a device_t, which saves us having to construct
  device names when the driver is detached.

- add a DEV_AUDIO type for devices.

sync with HEAD

sync with head.

For each symtab, remember which symbols have the minimum and maximum value.
When returning a "close" symbol, make sure the value being searched for is
within the symtab.  This prevents ddb matching addresses beyond the end of
the kernel.

Sync with HEAD.

sync with head

sync with HEAD

Sync with HEAD

Ignore symbols marked undefined.

sync with head.

Sync with head.

sync with head.

Sync with head.

Don't panic if we don't find a symbol or string table. Perhaps the kernel
has been stripped?

Sync with HEAD.

Kill caddr_t; there will be some MI fallout, but it will be fixed shortly.

sync with head.

sync with head.

Sync with head.

Pass a simple ELF header to ksyms_init_explicit with the minimum contents
required to initialize ksyms_hdr.  Otherwise LKMs do not work when using
ksyms_init_explicit instead of ksyms_init, as is the case of booting an
i386 kernel using Multiboot.

remove some __unused from function parameters.

Add a function (ksyms_init_explicit) to add a symbol table when we know the
exact address of the symtab and strtab ELF sections contents beforehand.

This will be used in i386's Multiboot code to add the initial kernel ksyms
without having to prepare a minimal ELF image that matches the format
expected by the reguluar ksyms_init function.

This part was reviewed by cube@ and successfully passes a full i386 release
build.

sync with head

- sprinkle __unused on function decls.
- fix a couple of unused bugs
- no more -Wno-unused for i386

sync with head.

merge ktrace-lwp.

Sync with HEAD. Here we go again...

Pull up revision 1.26 (requested by riz in ticket #2037):
Use %zx in a format string to print a size_t, not %lx, so a kernel
with KSYMS_DEBUG will compile.

Pull up revision 1.26 (requested by riz in ticket #508):
Use %zx in a format string to print a size_t, not %lx, so a kernel
with KSYMS_DEBUG will compile.

Use %zx in a format string to print a size_t, not %lx, so a kernel
with KSYMS_DEBUG will compile.

Use ANSI function decls.  Apply some static.

- add const.
- remove unnecessary casts.
- add __UNCONST casts and mark them with XXXUNCONST as necessary.

sync with -current

sync with head.  xen and whitespace.  xen part is not finished.

Sync with HEAD.

Hi Perry!

nuke trailing whitespace

Sync with HEAD.

The way I handled /dev/ksyms requests vs. kernel requests was completely
broken.  Inside the kernel, we always have to use the real values of the
st_name fields, and only do the math when the request comes from userland.

No need for ksyms_getval_from{kernel,userland} hack anymore.  However, a
different version will be asked for pull-up in -2{,-0}, one that doesn't
break the API, that is.

Fixes PR#29133 from Jens Kessmeier.

Fix the sync with head I botched.

Sync with HEAD.

Sync with HEAD

Move detection of a special symbol into a separate function.  Add some more
special symbols.

Support really large LKMs.  Find out how much space is needed for symbols
and then allocate it on demand.  Rename some common symbols (__bss_start,
_edata, _end, __start_link_set_*, __stop_link_set_*) so that ".<module>"
is appended to them.  This shrinks an amd64 kernel by 20KB of BSS.

s/sumbols/symbols/

If ksyms have not been initialized, return ENXIO in ksymsopen instead of
ksymsread, because ksyms client test availability with open() and not
read().

o Fix a bug in ksyms that changed the real meaning of st_name entries for
  symbols, and made it impossible for the kernel to use that value, and
  correctly find symbols from LKMs.
o Allow LKM users to use DDB to debug the entry function of a LKM by
  loading the symbol table with the temporary name /lkmtemp/ before calling
  it, and then renaming it once we know the module name.

Approved by ragge@.

Do not try to enter more than MAX_INT16 symbols into the patricia tree;
the not-entered symbols will be found anyway but via a linear-search.
This only happens if something is wrong when linking the kernel.
Fixes problems reported on port-hp700.

fix uninitialized variables. one of them is a compiler bug.

long -> unsigned long.

Apply the aborted ktrace-lwp changes to a specific branch.  This is just for
others to review, I'm concerned that patch fuziness may have resulted in some
errant code being generated but I'll look at that later by comparing the diff
from the base to the branch with the file I attempt to apply to it.  This will,
at the very least, put the changes in a better context for others to review
them and attempt to tinker with removing passing of 'struct lwp' through
the kernel.

Back out the lwp/ktrace changes. They contained a lot of colateral damage,
and need to be examined and discussed more.

Pass lwp pointers throughtout the kernel, as required, so that the lwpid can
be inserted into ktrace records.  The general change has been to replace
"struct proc *" with "struct lwp *" in various function prototypes, pass
the lwp through and use l_proc to get the process pointer when needed.

Bump the kernel rev up to 1.6V

Add __KERNEL_RCSID()

use strlcpy.  [fixed off-by-one in subr_prop.c]

make couple ksym functions' arguments const

Remove useless entries from the symbol table at load.
Add patricia-tree-style lookup code for symbols (for fast lookups).

#ifdef KSYMS_DEBUG should be #if NKSYMS.

Fix build problems for kernel configurations without the "ksyms"
pseudo-device.

Enable the ioctl's.

Make ksymms_init() take void * parameters instead of caddr_t.

Mobe the SYMTAB_SPACE stuff to ksyms_init, so that it can be used without
DDB compiled-in.

Explicitly cast printf arg to long, from Tom Spindler.

Basic implementation of in-kernel symbol table manager + /dev/ksyms.