Hi, Here is the 2nd version of RFC series to use ftrace_regs instead of pt_regs. But this includes the generic part and minimum modifications of arch dependent code. (e.g. not including rethook for arm64.) This series is based on the discussion at https://lore.kernel.org/all/20230801112036.0d4ee60d@xxxxxxxxxxxxxxxxxx/ This version includes 1 patch to expose ftrace_regs. so - Simply replace pt_regs in fprobe_entry_handler with ftrace_regs. - Expose ftrace_regs even if CONFIG_FUNCTION_TRACER=n. - Replace pt_regs in rethook and fprobe_exit_handler with ftrace_regs. This introduce a new HAVE_PT_REGS_COMPAT_FTRACE_REGS which means ftrace_regs is just a wrapper of pt_regs (except for arm64, other architectures do this) - Update fprobe-events to use ftrace_regs natively. - Introduce ftrace_partial_regs(). (This changes ARM64 which needs a custom implementation) - Update bpf multi-kprobe handler use ftrace_partial_regs(). Florent, feel free to add your rethook for arm64, but please do not remove kretprobe trampoline yet. It is another discussion point. We may be possible to use ftrace_regs for kretprobe by ftrace_partial_regs() but kretprobe allows nest probe. (maybe we can skip that case?) This series can also be found below branch. https://git.kernel.org/pub/scm/linux/kernel/git/mhiramat/linux.git/log/?h=topic/fprobe-ftrace-regs Thank you, --- Masami Hiramatsu (Google) (6): fprobe: Use fprobe_regs in fprobe entry handler tracing: Expose ftrace_regs regardless of CONFIG_FUNCTION_TRACER fprobe: rethook: Use fprobe_regs in fprobe exit handler and rethook tracing/fprobe: Enable fprobe events with CONFIG_DYNAMIC_FTRACE_WITH_ARGS ftrace: Add ftrace_partial_regs() for converting ftrace_regs to pt_regs bpf: Enable kprobe_multi feature if CONFIG_FPROBE is enabled arch/Kconfig | 1 + arch/arm64/include/asm/ftrace.h | 11 ++++++ arch/loongarch/Kconfig | 1 + arch/s390/Kconfig | 1 + arch/x86/Kconfig | 1 + arch/x86/kernel/rethook.c | 9 +++-- include/linux/fprobe.h | 4 +- include/linux/ftrace.h | 56 ++++++++++++++++++----------- include/linux/rethook.h | 11 +++--- kernel/kprobes.c | 9 ++++- kernel/trace/Kconfig | 9 ++++- kernel/trace/bpf_trace.c | 14 +++++-- kernel/trace/fprobe.c | 8 ++-- kernel/trace/rethook.c | 16 ++++---- kernel/trace/trace_fprobe.c | 76 ++++++++++++++++++++++++--------------- kernel/trace/trace_probe_tmpl.h | 2 + lib/test_fprobe.c | 10 +++-- samples/fprobe/fprobe_example.c | 4 +- 18 files changed, 154 insertions(+), 89 deletions(-) -- Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
