Messages in this thread | | | Date | Mon, 21 Oct 2013 09:47:21 +0530 | Subject | Re: [PATCH RFC v2 0/6] ARM64: Add kernel probes(Kprobes) support | From | Sandeepa Prabhu <> |
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On 18 October 2013 14:02, Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> wrote: > (2013/10/17 20:17), Sandeepa Prabhu wrote: >> This patchset adds support for kernel probes(kprobes), jump probes(jprobes) >> and return probes(kretprobes) support for ARM64. >> >> Kprobes mechanism make use of software breakpoint and single stepping >> support available in ARM v8 kernel. >> > > Thank you! This looks much better for me now. ;) > >> This patchset make use of (and dependant upon) dynamic kernel patching >> feature published in patch series: https://lkml.org/lkml/2013/10/15/891 >> >> changes: v1 -> v2 >> 1. Implemented review comments on v1 >> 2. Debug montior hooks implementation is changed to use rwlocks >> instead of rcu and spinlock. > > Eventually, we'd better reconsider using rcu there, or prohibit probing > readlock related functions. For the first step, this will be good. Okay, can be done while optimizing kprobes right, since systemtap/ktap is yet to be verified on this patchset, so can expect more scope for optimizing the paths for performance. > >> 3. Enabled recursing in kprobes handler for kprobes re-enter support. >> 4. Re-split the patchset to seperate single-stepping, simulation and >> kretprobes features. >> 5. instruction simulation is made independent of 'struct kprobes' >> 6. Added 'Linaro Copyright' statements in new added files. >> 7. Used arm64 instead of aarch64 in file names and comments. >> >> Tested on ARM v8 fast model with sample modules from: samples/kprobes/ >> >> Sandeepa Prabhu (6): >> arm64: support single-step and breakpoint handler hooks >> arm64: Kprobes with single stepping support >> arm64: Kprobes instruction simulation support >> arm64: Add kernel return probes support(kretprobes) >> arm64: Enable kprobes support for arm64 platform >> kprobes: Add cases for arm and arm64 in sample module >> >> arch/arm64/Kconfig | 2 + >> arch/arm64/configs/defconfig | 20 +- >> arch/arm64/include/asm/debug-monitors.h | 21 + >> arch/arm64/include/asm/kprobes.h | 60 +++ >> arch/arm64/include/asm/probes.h | 50 +++ >> arch/arm64/include/asm/ptrace.h | 6 + >> arch/arm64/kernel/Makefile | 2 + >> arch/arm64/kernel/condn-helpers.c | 120 ++++++ >> arch/arm64/kernel/debug-monitors.c | 86 +++- >> arch/arm64/kernel/entry.S | 2 + > > >> arch/arm64/kernel/kprobes-arm64.c | 313 +++++++++++++++ >> arch/arm64/kernel/kprobes-arm64.h | 30 ++ > > One comment, this name looks a bit wired. Since it seems that these are > for instruction decoding, can we merge it with probe-decode.h and > rename it as probe-decode.{h,c}? When we implement uprobes, we still > can expand it (add the decoding table for uprobes in the probe-decode.c). probe-decode.c looks fine, as uprobes decode table can be added in same place. -TODO for the next version.
> >> arch/arm64/kernel/kprobes.c | 682 ++++++++++++++++++++++++++++++++ >> arch/arm64/kernel/kprobes.h | 30 ++ >> arch/arm64/kernel/probes-decode.h | 110 ++++++ >> arch/arm64/kernel/simulate-insn.c | 184 +++++++++ >> arch/arm64/kernel/simulate-insn.h | 33 ++ >> arch/arm64/kernel/vmlinux.lds.S | 1 + >> samples/kprobes/kprobe_example.c | 16 + >> 19 files changed, 1756 insertions(+), 12 deletions(-) > > BTW, is there any public git repository which has this series? Yes, uploaded on linaro git: https://git.linaro.org/gitweb?p=people/sandeepa.prabhu/linux-aarch64.git;a=shortlog;h=refs/heads/arm64-kprobes-v2
> > Thank you again! > > -- > Masami HIRAMATSU > IT Management Research Dept. Linux Technology Center > Hitachi, Ltd., Yokohama Research Laboratory > E-mail: masami.hiramatsu.pt@hitachi.com > >
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