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[v11,0/6] Add kprobe and kretprobe support for LoongArch

Message ID 1673688444-24251-1-git-send-email-yangtiezhu@loongson.cn
Headers
Series Add kprobe and kretprobe support for LoongArch |

Message

Tiezhu Yang Jan. 14, 2023, 9:27 a.m. UTC 
  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 (6):
  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
  LoongArch: Use common function sign_extend64()

 arch/loongarch/Kconfig                     |   2 +
 arch/loongarch/include/asm/asm.h           |  10 +
 arch/loongarch/include/asm/inst.h          |  28 +-
 arch/loongarch/include/asm/kprobes.h       |  58 +++++
 arch/loongarch/include/asm/ptrace.h        |   1 +
 arch/loongarch/kernel/Makefile             |   2 +
 arch/loongarch/kernel/alternative.c        |   6 +-
 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 +
 15 files changed, 741 insertions(+), 16 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