pointer doesn't point to the first instruction of that function, but
rather to a descriptor. The descriptor has the address of the first
instruction, as well as the value of the global pointer. The symbol
table doesn't know anything about descriptors, so if you lookup the
name of a function you get the address of the first instruction. The
cast from the address, which is the result of the symbol lookup, to a
function pointer as is done in db_fncall is therefore invalid.
Abstract this detail behind the DB_CALL macro. By default DB_CALL is
defined as db_fncall_generic, which yields the old behaviour. On ia64
the macro is defined as db_fncall_ia64, in which a descriptor is
constructed to yield a valid function pointer.
While here, introduce DB_MAXARGS. DB_MAXARGS replaces the existing
(local) MAXARGS. The DB_MAXARGS macro can be defined by platforms to
create a convenient maximum. By default this will be the legacy 10.
On ia64 we define this macro to be 8, for 8 is the maximum number of
arguments that can be passed in registers. This avoids having to
implement spilling of arguments on the memory stack.
Approved by: re (dwhite)
control the number of lines per page rather than a constant. The variable
can be examined and changed in ddb as '$lines'. Setting the variable to
0 will effectively turn off paging.
- Change db_putchar() to force out pending whitespace before outputting
newlines and carriage returns so that one can rub out content on the
current line via '\r \r' type strings.
- Change the simple pager to rub out the --More-- prompt explicitly when
the routine exits.
- Add some aliases to the simple pager to make it more compatible with
more(1): 'e' and 'j' do a single line. 'd' does half a page, and
'f' does a full page.
MFC after: 1 month
Inspired by: kris
the thread ID and call db_trace_thread().
Since arm has all the logic in db_stack_trace_cmd(), rename the
new DB_COMMAND function to db_stack_trace to avoid conflicts on
arm.
While here, have db_stack_trace parse its own arguments so that
we can use a more natural radix for IDs. If the ID is not a thread
ID, or more precisely when no thread exists with the ID, try if
there's a process with that ID and return the first thread in it.
This makes it easier to print stack traces from the ps output.
requested by: rwatson@
tested on: amd64, i386, ia64
Most of the changes are a direct result of adding thread awareness.
Typically, DDB_REGS is gone. All registers are taken from the
trapframe and backtraces use the PCB based contexts. DDB_REGS was
defined to be a trapframe on all platforms anyway.
Thread awareness introduces the following new commands:
thread X switch to thread X (where X is the TID),
show threads list all threads.
The backtrace code has been made more flexible so that one can
create backtraces for any thread by giving the thread ID as an
argument to trace.
With this change, ia64 has support for breakpoints.
callout when a specified number of lines have been output. This can be
used to implement pagers for ddb commands that output a lot of text. A
simple paging function is included that automatically rearms itself when
fired.
Reviewed by: bde, julian
(show thread {address})
Remove the IDLE kse state and replace it with a change in
the way threads sahre KSEs. Every KSE now has a thread, which is
considered its "owner" however a KSE may also be lent to other
threads in the same group to allow completion of in-kernel work.
n this case the owner remains the same and the KSE will revert to the
owner when the other work has been completed.
All creations of upcalls etc. is now done from
kse_reassign() which in turn is called from mi_switch or
thread_exit(). This means that special code can be removed from
msleep() and cv_wait().
kse_release() does not leave a KSE with no thread any more but
converts the existing thread into teh KSE's owner, and sets it up
for doing an upcall. It is just inhibitted from being scheduled until
there is some reason to do an upcall.
Remove all trace of the kse_idle queue since it is no-longer needed.
"Idle" KSEs are now on the loanable queue.
MD function is just a wrapper around db_stack_trace_cmd() that prints out
a backtrace of curthread. Currently, this function is only implemented
on i386 and alpha (and the alpha version isn't quite tested yet, will do
that in a bit). Other changes:
- For i386, fix a bug in the raw frame address case. The eip we extract
from the passed in frame address does not match the frame we received.
Thus, instead of printing a bogus frame with the wrong eip, go ahead
and advance frame down to the same frame as the eip we are using.
- For alpha, attempt to add a way of doing a raw trace for alpha. Instead
of passing a frame address in 'addr', pass in a pointer to a structure
containing PC and KSP and use those to start the backtrace. The alpha
db_print_backtrace() uses asm to read in the current PC and KSP values
into such a request.
Tested on: i386
Requested by: many
'dwatch'. The new commands install hardware watchpoints if supported
by the architecture and if there are enough registers to cover the
desired memory area.
No objection by: audit@, hackers@
MFC after: 2 weeks
ddb is entered. Don't refer to `in_Debugger' to see if we
are in the debugger. (The variable used to be static in Debugger()
and wasn't updated if ddb is entered via traps and panic anyway.)
- Don't refer to `in_Debugger'.
- Add `db_active' to i386/i386/db_interface.d (as in
alpha/alpha/db_interface.c).
- Remove cnpollc() stub from ddb/db_input.c.
- Add the dbctl function to syscons, pcvt, and sio. (The function for
pcvt and sio is noop at the moment.)
Jointly developed by: bde and me
(The final version was tweaked by me and not reviewed by bde. Thus,
if there is any error in this commit, that is entirely of mine, not
his.)
Some changes were obtained from: NetBSD
I'm not too happy about the result either, but at least it has less
chance of backfiring.
This particular feature could be called "a mess" without offending
anybody.
Use them to `make gcc -Wformat' check formats for all printf-like
and scanf-like functions in /usr/src except for the err()/warn()
family. err() isn't quite printf-like since its format arg can
legitimately be NULL. syslog() isn't quite printf-like, but gcc
already accepts %m, even for plain printf() when it shouldn't.
FreeBSD/alpha. The most significant item is to change the command
argument to ioctl functions from int to u_long. This change brings us
inline with various other BSD versions. Driver writers may like to
use (__FreeBSD_version == 300003) to detect this change.
The prototype FreeBSD/alpha machdep will follow in a couple of days
time.
This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.
Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.
The details are hidden in the DB_COMMAND(cmd_name, func_name) and
DB_SHOW_COMMAND(cmd_name, func_name) macros. DB_COMMAND() adds to
the top-level ddb command table and DB_SHOW_COMMAND adds to the
`show' subtable. Most external commands will probably be `show'
commands with no side effects. They should check their pointer
args more carefully than `show map' :-), or ddb should trap internal
faults better (like it does for memory accesses).
The vm ddb commands are temporarily unattached.
ddb.h:
Also declare `db_indent' and db_iprintf() which will replace vm's
`indent' and iprintf().
