[This update just notes that it appears that combination
${MK_GDB} == no && ${MK_GDB_LIBEXEC} == yes is not intended
to be used, effectively eliminating "THING #1" of 0-2.]On 2017-May-6, at 10:03 PM, Mark Millard <markmi at dsl-only.net> wrote: > On 2017-May-6, at 5:21 PM, Mark Millard <markmi at dsl-only.net> wrote: > >> On: >> >> # uname -apKU >> FreeBSD FBSDG4S 12.0-CURRENT FreeBSD 12.0-CURRENT r317820M powerpc powerpc >> 1200030 1200030 >> >> When I attempt to use: >> >> # which kgdb >> /usr/local/bin/kgdb >> >> that was from building devel/gdb for: >> >> # svnlite info /usr/ports | grep "Re[plv]" >> Relative URL: ^/head >> Repository Root: https://svn.freebsd.org/ports >> Repository UUID: 35697150-7ecd-e111-bb59-0022644237b5 >> Revision: 440115 >> Last Changed Rev: 440115 >> >> (built via gcc 4.2.1: not via clang: I >> experiment with clang for powerpc and >> powerpc64 so I'm being explicit) >> >> I end up getting the following sort of result: >> >> # kgdb /usr/lib/debug/boot/kernel/kernel.debug /var/crash/vmcore.4 >> . . . >> Reading symbols from /usr/lib/debug/boot/kernel/kernel.debug...done. >> ABI doesn't support a vmcore target >> >> That message is from: /usr/ports/devel/gdb/files/kgdb/fbsd-kvm.c . . . >> >> static void >> kgdb_trgt_open(const char *arg, int from_tty) >> { >> struct fbsd_vmcore_ops *ops = (struct fbsd_vmcore_ops *) >> gdbarch_data (target_gdbarch(), fbsd_vmcore_data); >> . . . >> if (ops == NULL || ops->supply_pcb == NULL || ops->cpu_pcb_addr == >> NULL) >> error ("ABI doesn't support a vmcore target"); >> . . . >> >> It appears that there is no kernel debugging >> supported for TARGET_ARCH=powerpc currently. >> (The system no longer has its own gdb related >> materials.) > > I've discovered more context and have found > a few of issues in how things are currently > set up. > > THING #0: > > It appears that usr.sbin/crashinfo/crashinfo.sh assumes > that /usr/local/bin/gdb will work better for all architectures, > including for kgdb types of activity: > > find_gdb() > { > local binary > > for binary in /usr/local/bin/gdb /usr/libexec/gdb /usr/bin/gdb; do > if [ -x ${binary} ]; then > GDB=${binary} > return > fi > done > } > > But it appears that on powerpc /usr/local/bin/gdb and > /usr/local/bin/kgdb do not support TARGET_ARCH=powerpc > at all for such activity. > > > THING #1: > > Another oddity is for the combination: > > ${MK_GDB} == no && ${MK_GDB_LIBEXEC} == yes > > where the tools/build/mk/OptionalObsoleteFiles.inc > logic then adds the libexec gdb and kgdb to > OLD_FILES : > > .if ${MK_GDB} == no || ${MK_GDB_LIBEXEC} == no > OLD_FILES+=usr/libexec/gdb > OLD_FILES+=usr/libexec/kgdb > .endif > > so doing a delete-old removes the only system > gdb and kgdb that are installed for such a > context. It does this because of: > > ${MK_GDB} == no > > (And that explains why I thought gdb and kgdb > were not in the system.) Looking around at how WITH_GDB and WITH_GDB_LIBEXEC and the MK_ variants are used it appears that the: ${MK_GDB} == no && ${MK_GDB_LIBEXEC} == yes combination is not intended to be used. > THING #2: > > /usr/libexec/kgdb (when present) does not support the > powerpc architecture for head either . . . > > On a head -r317820 powerpc I attempted: > > # /usr/libexec/kgdb /usr/lib/debug/boot/kernel/kernel.debug > /var/crash/vmcore.7 > GNU gdb 6.1.1 [FreeBSD] > Copyright 2004 Free Software Foundation, Inc. > GDB is free software, covered by the GNU General Public License, and you are > welcome to change it and/or distribute copies of it under certain conditions. > Type "show copying" to see the conditions. > There is absolutely no warranty for GDB. Type "show warranty" for details. > This GDB was configured as "powerpc-marcel-freebsd"... > Failed to open vmcore: unsupported architecture === Mark Millard markmi at dsl-only.net _______________________________________________ freebsd-toolchain@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-toolchain To unsubscribe, send any mail to "freebsd-toolchain-unsubscr...@freebsd.org"
