Messages in this thread | | | Date | Fri, 17 Jul 2020 22:48:26 +0900 | From | Masami Hiramatsu <> | Subject | Re: [PATCH v2 0/3] kgdb: Honour the kprobe blacklist when setting breakpoints |
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Hi Daniel,
On Thu, 16 Jul 2020 16:19:40 +0100 Daniel Thompson <daniel.thompson@linaro.org> wrote:
> kgdb has traditionally adopted a no safety rails approach to breakpoint > placement. If the debugger is commanded to place a breakpoint at an > address then it will do so even if that breakpoint results in kgdb > becoming inoperable. > > A stop-the-world debugger with memory peek/poke intrinsically provides > its operator with the means to hose their system in all manner of > exciting ways (not least because stopping-the-world is already a DoS > attack ;-) ). Nevertheless the current no safety rail approach is > difficult to defend, especially given kprobes can provide us with plenty > of machinery to mark the parts of the kernel where breakpointing is > discouraged. > > This patchset introduces some safety rails by using the existing kprobes > infrastructure and ensures this will be enabled by default on > architectures that implement kprobes. At present it does not cover > absolutely all locations where breakpoints can cause trouble but it will > block off several avenues, including the architecture specific parts > that are handled by arch_within_kprobe_blacklist().
This series looks good to me.
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
To fix the build error with ipw2x00 driver, please feel free to include my fix patch.
Thank you,
> > > Daniel Thompson (3): > kgdb: Honour the kprobe blocklist when setting breakpoints > kgdb: Use the kprobe blocklist to limit single stepping > kgdb: Add NOKPROBE labels on the trap handler functions > > include/linux/kgdb.h | 19 +++++++++++++++++++ > kernel/debug/debug_core.c | 25 +++++++++++++++++++++++++ > kernel/debug/gdbstub.c | 10 +++++++++- > kernel/debug/kdb/kdb_bp.c | 17 +++++++++++------ > kernel/debug/kdb/kdb_main.c | 10 ++++++++-- > lib/Kconfig.kgdb | 14 ++++++++++++++ > 6 files changed, 86 insertions(+), 9 deletions(-) > > -- > 2.25.4 >
-- Masami Hiramatsu <mhiramat@kernel.org>
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