the previous frame is in the usual place even for traps, interrupts
and syscalls in the kernel, because the assembly language stubs
don't change the frame pointer. The previous frame is just not for
the calling function. We may as well depend on this as on magic to
determine the trap frame address. The magic is in FRAME_SAVED_PC()
which elides the correct number of stubs (1) to go back to a pc that
matches the previous frame.
Removing fbsd_kern_frame_chain() fixes bugs in it. Xsyscall was
misspelled as _Xsyscall (gdb removes one leading underscore), so
the tf_syscall frame type was never found. This was harmless
because tf_normal works in all cases in fbsd_kern_frame_chain()
and Xsyscall is spelled correctly in fbsd_kern_frame_saved_pc()
where it matters. There were style bugs on almost every line,
starting with a primary indent of 7.
UPAGES layout.. it was entirely too comfortable with reading and writing
the U area before. I've changed it to use PT_GETREGS/PT_PUTREGS
ptrace ops instead of READ_U etc. The code to read the registers from
core dumps is a bandaid at best. It seems to have problems reading
core dumps from dynamic linked executables still, but at least static
dumps work.
I desperately need help from a gdb/bfd expert. :-) HELP!!
1) add Garrett Wollman's trap frame resolving mods
2) make the `proc' command (kernel debugging) really work
3) allow use of a pid with the `proc' command (previously you had to
provide the address of the proc structure)
Unfortunately, the `proc' command won't work while doing remote debugging.
the wild, slippery orgy commence!
Gary Jennejohn, too studly for his own good, has finally come through with
the new, improved gdb 4.13. This gdb features:
o kgdb support - if this works (and I urge folks to test it), we can
finally purge the old and hateful version of kgdb from our source
tree.
o attach/detach support. See comments in README.FreeBSD for more
details.
o Well, it's newer. Our previous version was 4.11.
Comments and flames to gj, of course! :-)
Thanks, Gary. Much appreciated. The previous state of gdb/kgdb has been a
thorn in all of our sides for some time..
Submitted by: gj
This is a greatly pared down version of the full gdb-4.12, all the
config stuff has been removed and the supporting libraries have
been stripped to a minimum. This is a 1.1.5 only port, I'll do a
more complete port for 2.0 which will have all the config stuff
and will install the gnu support libraries as system libraries like
we do for readline.
There wasn't much point for 1.1.5 since only gdb would use them so I
went for saving space instead. For 2.0 I'll config all the
other gnu tools to use them as well.
