Re: [REPOST PATCH v6 0/4] kgdb: Fix kgdb_roundup_cpus()

From: Catalin Marinas
Date: Fri Dec 07 2018 - 12:42:43 EST


On Tue, Dec 04, 2018 at 07:38:24PM -0800, Douglas Anderson wrote:
> Douglas Anderson (4):
> kgdb: Remove irq flags from roundup
> kgdb: Fix kgdb_roundup_cpus() for arches who used smp_call_function()
> kgdb: Don't round up a CPU that failed rounding up before
> kdb: Don't back trace on a cpu that didn't round up

FWIW, trying these on arm64 (ThunderX2) with CONFIG_KGDB_TESTS_ON_BOOT=y
on top of 4.20-rc5 doesn't boot. It looks like they leave interrupts
disabled when they shouldn't and it trips over the BUG at
mm/vmalloc.c:1380 (called via do_fork -> copy_process).

Now, I don't think these patches make things worse on arm64 since prior
to them the kgdb boot tests on arm64 were stuck in a loop (RUN
singlestep).

--
Catalin