Messages in this thread | | | From | Guo Ren <> | Date | Wed, 23 Nov 2022 23:15:22 +0800 | Subject | Re: [PATCH 1/2] riscv/ftrace: add DYNAMIC_FTRACE_WITH_DIRECT_CALLS support |
| |
Hi Song,
On Wed, Nov 23, 2022 at 10:20 PM Song Shuai <suagrfillet@gmail.com> wrote: > > This patch adds DYNAMIC_FTRACE_WITH_DIRECT_CALLS support for RISC-V. > > select the DYNAMIC_FTRACE_WITH_DIRECT_CALLS to provide the > register_ftrace_direct[_multi] interfaces allowing users to register > the customed trampoline (direct_caller) as the mcount for one or > more target functions. And modify_ftrace_direct[_multi] are also > provided for modifying direct_caller. > > To make the direct_caller and the other ftrace hooks (eg. function/fgraph > tracer, k[ret]probes) co-exist, a temporary register is nominated to > store the address of direct_caller in ftrace_regs_caller. After the > setting of the address direct_caller by direct_ops->func and the > RESTORE_REGS in ftrace_regs_caller, direct_caller will be jumped to > by the `jr` inst. > > Signed-off-by: Song Shuai <suagrfillet@gmail.com> > --- > arch/riscv/Kconfig | 1 + > arch/riscv/include/asm/ftrace.h | 6 ++++++ > arch/riscv/kernel/mcount-dyn.S | 4 ++++ > 3 files changed, 11 insertions(+) > > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig > index 39ec8d628cf6..d083ec08d0b6 100644 > --- a/arch/riscv/Kconfig > +++ b/arch/riscv/Kconfig > @@ -278,6 +278,7 @@ config ARCH_RV64I > select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 > select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && $(cc-option,-fpatchable-function-entry=8) > select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE > + select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS > select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL > select HAVE_FUNCTION_GRAPH_TRACER > select HAVE_FUNCTION_TRACER if !XIP_KERNEL && !PREEMPTION > diff --git a/arch/riscv/include/asm/ftrace.h b/arch/riscv/include/asm/ftrace.h > index 01bebb28eabe..be4d57566139 100644 > --- a/arch/riscv/include/asm/ftrace.h > +++ b/arch/riscv/include/asm/ftrace.h > @@ -114,6 +114,12 @@ struct ftrace_regs; > void ftrace_graph_func(unsigned long ip, unsigned long parent_ip, > struct ftrace_ops *op, struct ftrace_regs *fregs); > #define ftrace_graph_func ftrace_graph_func > + > +static inline void arch_ftrace_set_direct_caller(struct pt_regs *regs, unsigned long addr) > +{ > + regs->t1 = addr; How about regs->t0 = addr; ? And delete all mcount-dyn.S modification. > +} > + > #endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */ > > #endif /* __ASSEMBLY__ */ > diff --git a/arch/riscv/kernel/mcount-dyn.S b/arch/riscv/kernel/mcount-dyn.S > index 466c6ef217b1..b89c85a58569 100644 > --- a/arch/riscv/kernel/mcount-dyn.S > +++ b/arch/riscv/kernel/mcount-dyn.S > @@ -233,6 +233,7 @@ ENDPROC(ftrace_caller) > #else /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */ > ENTRY(ftrace_regs_caller) > SAVE_ABI_REGS 1 > + REG_S x0, PT_T1(sp) > PREPARE_ARGS > > ftrace_regs_call: > @@ -241,7 +242,10 @@ ftrace_regs_call: > > > RESTORE_ABI_REGS 1 > + bnez t1,.Ldirect > jr t0 > +.Ldirect: > + jr t1 > ENDPROC(ftrace_regs_caller) > > ENTRY(ftrace_caller) > -- > 2.20.1 >
-- Best Regards Guo Ren
| |