kernel message buffer/log. Its off by default and can be switched on in the
kernel configuration on build time, be set as a variable in ddb and be set
using sysctl.
This adds the sysctl value
ddb.tee_msgbuf = 0
by default.
The functionality is especially added and aimed for developers who are not
blessed with a serial console and wish to keep all their ddb output in the
log. Specifying /l as a modifier to some selected commands will also put
the output in the log but not all commands provide one nor has the same
meaning for all commands.
This feature could in the future also be implemented as an ddb command but
that could lead to more bloat allthough maybe easier for non developpers to
use when mailing their backtraces from kernel crashes.
Gone are the old kern_sysctl(), cpu_sysctl(), hw_sysctl(),
vfs_sysctl(), etc, routines, along with sysctl_int() et al. Now all
nodes are registered with the tree, and nodes can be added (or
removed) easily, and I/O to and from the tree is handled generically.
Since the nodes are registered with the tree, the mapping from name to
number (and back again) can now be discovered, instead of having to be
hard coded. Adding new nodes to the tree is likewise much simpler --
the new infrastructure handles almost all the work for simple types,
and just about anything else can be done with a small helper function.
All existing nodes are where they were before (numerically speaking),
so all existing consumers of sysctl information should notice no
difference.
PS - I'm sorry, but there's a distinct lack of documentation at the
moment. I'm working on sysctl(3/8/9) right now, and I promise to
watch out for buses.
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@.
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
to select the right format string (at compile time) when displaying
variables of type db_expr_t.
This fixes a problem where ddb(4) would only display the low 32-bits
of registers for an ILP32 kernel on SH5, even though registers
(and db_expr_t) are always 64-bits wide.
message buffer has not yet been set up, mimicking code from the top of
the sysctl routine for retrieving the message buffer.
(2) Add a /l modifier to the trace command. This makes it print the
backtrace using printf() instead of db_printf(), which has the nice
side-effect of also putting it into the message buffer. A kernel with
ddb in it but disabled (ie, ddb.onpanic set to zero) will print a
backtrace (which ends up in the message buffer) before dumping (or
not, depending on the value of kern.dump_on_panic) and rebooting, but
if ddb is not disabled, the backtrace is not printed, and there's no
way to get it to display a backtrace such that you can retrieve it
after the dump. The backtrace printed by gdb is sometimes a little
different.
(3) Documentation for the above.
breakpoint address before it's used. Currently a no-op on all but sh5.
This is useful on sh5, for example, to mask off the instruction
type encoding in the bottom two address bits, and makes it possible
to do "db> break $rXX" instead of manually munging the address.
done by Artur Grabowski and Thomas Nordin for OpenBSD, which is more
efficient in several ways than the callwheel implementation that it is
replacing. It has been adapted to our pre-existing callout API, and
also provides the slightly more efficient (and much more intuitive)
API (adapted to the callout_*() naming scheme) that the OpenBSD version
provides.
Among other things, this shaves a bunch of cycles off rescheduling-in-
the-future a callout which is already scheduled, which the common case
for TCP timers (notably REXMT and KEEP).
The API has been simplified a bit, as well. The (very confusing to
a good many people) "ACTIVE" state for callouts has gone away. There
is now only "PENDING" (scheduled to fire in the future) and "EXPIRED"
(has fired, and the function called).
Kernel version bump not done; we'll ride the 1.6N bump that happened
with the malloc(9) change.
chs