| Message ID | 20230511093234.3123181-4-suagrfillet@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | riscv: Optimize function trace | expand |
Song Shuai <suagrfillet@gmail.com> writes: > 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> > Tested-by: Guo Ren <guoren@kernel.org> > Signed-off-by: Guo Ren <guoren@kernel.org> Thank you for addressing my comments, and for your work on WITH_DIRECT_CALLS! Acked-by: Björn Töpel <bjorn@rivosinc.com>
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index e0632493482f..fdf0b219a02c 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -144,6 +144,7 @@ config RISCV select UACCESS_MEMCPY if !MMU select ZONE_DMA32 if 64BIT select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && (CLANG_SUPPORTS_DYNAMIC_FTRACE || GCC_SUPPORTS_DYNAMIC_FTRACE) + select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL select HAVE_FUNCTION_GRAPH_TRACER diff --git a/arch/riscv/include/asm/ftrace.h b/arch/riscv/include/asm/ftrace.h index 84f856a3286e..84904c1e4369 100644 --- a/arch/riscv/include/asm/ftrace.h +++ b/arch/riscv/include/asm/ftrace.h @@ -114,6 +114,14 @@ 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; +} +#define arch_ftrace_set_direct_caller(fregs, addr) \ + __arch_ftrace_set_direct_caller(&(fregs)->regs, addr) #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 fb8286b80cfc..b6f4e1847d61 100644 --- a/arch/riscv/kernel/mcount-dyn.S +++ b/arch/riscv/kernel/mcount-dyn.S @@ -231,6 +231,7 @@ ENDPROC(ftrace_caller) #else /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */ ENTRY(ftrace_regs_caller) + mv t1, zero SAVE_ABI_REGS 1 PREPARE_ARGS @@ -239,7 +240,10 @@ ftrace_regs_call: call ftrace_stub RESTORE_ABI_REGS 1 + bnez t1,.Ldirect jr t0 +.Ldirect: + jr t1 ENDPROC(ftrace_regs_caller) ENTRY(ftrace_caller) @@ -254,3 +258,9 @@ ftrace_call: jr t0 ENDPROC(ftrace_caller) #endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */ + +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS +SYM_CODE_START(ftrace_stub_direct_tramp) + jr t0 +SYM_CODE_END(ftrace_stub_direct_tramp) +#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */