Hi, Here is the 5th version of the series to use ftrace_regs instead of pt_regs in fprobe. The previous version is here; https://lore.kernel.org/all/169280372795.282662.9784422934484459769.stgit@devnote2/ In this version, I decided to use perf's own per-cpu pt_regs array to copy the required registers[8/12]. Thus this version adds a patch which adds a new ftrace_fill_perf_regs() API. So the ftrace_partial_regs() will be used for BPF and ftrace_fill_perf_regs() is used for perf events. This also adds a fix for RISCV ftrace[1/12]. When kernel is built with disabling CONFIG_DYNAMIC_FTRACE_WITH_REGS on RISCV, it stores partial registers on the stack, but it doesn't make it fit to struct ftrace_regs. But since the 4th argument of ftrace_func_t is ftrace_regs *, it breaks the ABI. So fixing it to save registers on ftrace_regs (== pt_regs on RISCV). Another new patch [3/12] is adding a comment about the requirements for the ftrace_regs. - RISCV ftrace fix to save registers on struct ftrace_regs correctly. - Document fix for the current fprobe callback prototype. - Add a comment of requirement for the ftrace_regs. - Simply replace pt_regs in fprobe_entry_handler with ftrace_regs. - Expose ftrace_regs even if CONFIG_FUNCTION_TRACER=n. - Introduce ftrace_partial_regs(). (This changes ARM64 which needs a custom implementation) - Introduce ftrace_fill_perf_regs() for perf pt_regs. - Replace pt_regs in rethook and fprobe_exit_handler with ftrace_regs. This introduce a new HAVE_PT_REGS_TO_FTRACE_REGS_CAST 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. - Update bpf multi-kprobe handler use ftrace_partial_regs(). - Update document for new fprobe callbacks. - Add notes for the $argN and $retval. This series can be applied against the trace-v6.6-rc2 on linux-trace tree. 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) (12): riscv: ftrace: Fix to pass correct ftrace_regs to ftrace_func_t functions Documentation: probes: Add a new ret_ip callback parameter tracing: Add a comment about the requirements of the ftrace_regs fprobe: Use ftrace_regs in fprobe entry handler tracing: Expose ftrace_regs regardless of CONFIG_FUNCTION_TRACER fprobe: rethook: Use ftrace_regs in fprobe exit handler and rethook tracing: Add ftrace_partial_regs() for converting ftrace_regs to pt_regs tracing: Add ftrace_fill_perf_regs() for perf event tracing/fprobe: Enable fprobe events with CONFIG_DYNAMIC_FTRACE_WITH_ARGS bpf: Enable kprobe_multi feature if CONFIG_FPROBE is enabled Documentation: probes: Update fprobe document to use ftrace_regs Documentation: tracing: Add a note about argument and retval access Documentation/trace/fprobe.rst | 18 +++-- Documentation/trace/fprobetrace.rst | 8 ++ Documentation/trace/kprobetrace.rst | 8 ++ arch/Kconfig | 1 arch/arm64/include/asm/ftrace.h | 18 +++++ arch/loongarch/Kconfig | 1 arch/loongarch/kernel/rethook.c | 10 +-- arch/loongarch/kernel/rethook.h | 4 + arch/powerpc/include/asm/ftrace.h | 7 ++ arch/riscv/kernel/mcount-dyn.S | 67 ++++++++---------- arch/riscv/kernel/probes/rethook.c | 12 ++- arch/riscv/kernel/probes/rethook.h | 6 +- arch/s390/Kconfig | 1 arch/s390/include/asm/ftrace.h | 9 ++ arch/s390/kernel/rethook.c | 10 ++- arch/s390/kernel/rethook.h | 2 - arch/x86/Kconfig | 1 arch/x86/include/asm/ftrace.h | 7 ++ arch/x86/kernel/rethook.c | 13 ++-- include/linux/fprobe.h | 4 + include/linux/ftrace.h | 128 +++++++++++++++++++++++++++++------ include/linux/rethook.h | 11 ++- kernel/kprobes.c | 10 ++- kernel/trace/Kconfig | 9 ++ kernel/trace/bpf_trace.c | 14 ++-- kernel/trace/fprobe.c | 10 +-- kernel/trace/rethook.c | 16 ++-- kernel/trace/trace_fprobe.c | 70 +++++++++++-------- kernel/trace/trace_probe_tmpl.h | 2 - lib/test_fprobe.c | 10 +-- samples/fprobe/fprobe_example.c | 4 + 31 files changed, 327 insertions(+), 164 deletions(-) -- Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
