Re: [PATCH v12 0/5] Add kprobe and kretprobe support for LoongArch

[Huacai Chen]

Hi, Masami,

Could you please pay some time to review this series? Thank you.

Huacai

On Wed, Jan 18, 2023 at 10:01 AM Tiezhu Yang <yangtiezhu@xxxxxxxxxxx> wrote:
>
> v12:
>   -- Rebase on the latest code
>   -- Fix -Wmissing-prototypes warning when make W=1
>   -- Drop patch #6 "Use common function sign_extend64()"
>      since it has been applied yet
>
> v11:
>   -- Rebase on the latest code
>   -- Address all the review comments, thank you all
>   -- Modify arch_prepare_kprobe() and setup_singlestep()
>      to make the probe logic more clear
>   -- Mark some assembler symbols as non-kprobe-able
>   -- Use common function sign_extend64()
>   -- Test 20 times about 36 hours for all the 71 assembler
>      functions annotated with SYM_CODE_START and SYM_FUNC_START
>      under arch/loongarch, especially test memset alone for 10
>      hours, no hang problems
>
> v10:
>   -- Remove sign_extend() based on the latest code
>   -- Rename insns_are_not_supported() to insns_not_supported()
>   -- Rename insns_are_not_simulated() to insns_not_simulated()
>   -- Set KPROBE_HIT_SSDONE if cur->post_handler is not NULL
>   -- Enable preemption for KPROBE_REENTER in kprobe_fault_handler()
>
> v9:
>   -- Rename sign_extended() to sign_extend()
>   -- Modify kprobe_fault_handler() to handle all of kprobe_status
>
> v8:
>   -- Put "regs->csr_prmd &= ~CSR_PRMD_PIE;" ahead to save one line
>   -- Add code comment of preempt_disable()
>   -- Put kprobe_page_fault() in __do_page_fault()
>   -- Modify the check condition of break insn in kprobe_breakpoint_handler()
>
> v7:
>   -- Remove stop_machine_cpuslocked() related code
>
> v6:
>   -- Add a new patch to redefine larch_insn_patch_text() with
>      stop_machine_cpuslocked()
>   -- Modify kprobe_breakpoint_handler() to consider the original
>      insn is break and return the correct value
>   -- Modify do_bp() to refresh bcode when original insn is break
>
> v5:
>   -- Rebase on the latest code
>   -- Use stop_machine_cpuslocked() to modify insn to avoid CPU race
>
> v4:
>   -- Remove kprobe_exceptions_notify() in kprobes.c
>   -- Call kprobe_breakpoint_handler() and kprobe_singlestep_handler()
>      in do_bp()
>
> v3:
>   -- Rebase on the latest code
>   -- Check the alignment of PC in simu_branch() and simu_pc()
>   -- Add ibar in flush_insn_slot()
>   -- Rename kprobe_{pre,post}_handler() to {post_}kprobe_handler
>   -- Add preempt_disable() and preempt_enable_no_resched()
>   -- Remove r0 save/restore and do some minor changes
>      in kprobes_trampoline.S
>   -- Do not enable CONFIG_KPROBES by default
>
> v2:
>   -- Split simu_branch() and simu_pc() into a single patch
>   -- Call kprobe_page_fault() in do_page_fault()
>   -- Add kprobes_trampoline.S for kretprobe
>
> Tiezhu Yang (5):
>   LoongArch: Simulate branch and PC* instructions
>   LoongArch: Add kprobe support
>   LoongArch: Add kretprobe support
>   LoongArch: Mark some assembler symbols as non-kprobe-able
>   samples/kprobes: Add LoongArch support
>
>  arch/loongarch/Kconfig                     |   2 +
>  arch/loongarch/include/asm/asm.h           |  10 +
>  arch/loongarch/include/asm/inst.h          |  20 ++
>  arch/loongarch/include/asm/kprobes.h       |  61 +++++
>  arch/loongarch/include/asm/ptrace.h        |   1 +
>  arch/loongarch/kernel/Makefile             |   2 +
>  arch/loongarch/kernel/entry.S              |   1 +
>  arch/loongarch/kernel/inst.c               | 123 +++++++++
>  arch/loongarch/kernel/kprobes.c            | 405 +++++++++++++++++++++++++++++
>  arch/loongarch/kernel/kprobes_trampoline.S |  96 +++++++
>  arch/loongarch/kernel/traps.c              |  11 +-
>  arch/loongarch/lib/memcpy.S                |   3 +
>  arch/loongarch/mm/fault.c                  |   3 +
>  samples/kprobes/kprobe_example.c           |   8 +
>  14 files changed, 741 insertions(+), 5 deletions(-)
>  create mode 100644 arch/loongarch/include/asm/kprobes.h
>  create mode 100644 arch/loongarch/kernel/kprobes.c
>  create mode 100644 arch/loongarch/kernel/kprobes_trampoline.S
>
> --
> 2.1.0
>
>