Re: [RFC][PATCH 4/7] x86/debug: Move historical SYSENTER junk into exc_debug_kernel()

From: peterz
Date: Fri Aug 21 2020 - 06:19:47 EST


On Thu, Aug 20, 2020 at 04:28:28PM +0100, Daniel Thompson wrote:

> Specifically I've entered the kdb in pretty much the simplest way
> possible: a direct call to kgdb_breakpoint() from a task context. I
> generate a backtrace to illustrate this, just to give you a better
> understanding of what might be happening) and then ran the single step.


> + make -C .. O=$PWD x86_64_defconfig
> + ../scripts/config --enable RUNTIME_TESTING_MENU
> + ../scripts/config --enable DEBUG_INFO --enable DEBUG_FS --enable KALLSYMS_ALL --enable MAGIC_SYSRQ --enable KGDB --enable KGDB_TESTS --enable KGDB_KDB --enable KDB_KEYBOARD --enable LKDTM
> + ../scripts/config --enable PROVE_LOCKING --enable DEBUG_ATOMIC_SLEEP
> + make olddefconfig


That asked me about a kgdb boottime selftest, which I figured was a good
idea, but even without my patches that seems to fail, and fail so that
it doesn't boot :/

> # echo g > /proc/sysrq-trigger

OK, I think I got that working with the latest set.

Thanks!