Re: [PATCH v3 3/3] kernel: debug: Centralize dbg_[de]activate_sw_breakpoints

[Doug Anderson]

Hi,

On Mon, Sep 14, 2020 at 6:02 AM Daniel Thompson
<daniel.thompson@xxxxxxxxxx> wrote:
>
> During debug trap execution we expect dbg_deactivate_sw_breakpoints()
> to be paired with an dbg_activate_sw_breakpoint(). Currently although
> the calls are paired correctly they are needlessly smeared across three
> different functions. Worse this also results in code to drive polled I/O
> being called with breakpoints activated which, in turn, needlessly
> increases the set of functions that will recursively trap if breakpointed.
>
> Fix this by moving the activation of breakpoints into the debug core.
>
> Signed-off-by: Daniel Thompson <daniel.thompson@xxxxxxxxxx>
> ---
>  kernel/debug/debug_core.c       | 2 ++
>  kernel/debug/gdbstub.c          | 1 -
>  kernel/debug/kdb/kdb_debugger.c | 2 --
>  3 files changed, 2 insertions(+), 3 deletions(-)

I like the idea, but previously the kgdb_arch_handle_exception() was
always called after the SW breakpoints were activated.  Are you sure
it's OK to swap those two orders across all architectures?

-Doug