diff options
author | Song Shuai <suagrfillet@gmail.com> | 2023-11-30 13:15:29 +0100 |
---|---|---|
committer | Palmer Dabbelt <palmer@rivosinc.com> | 2024-01-18 03:17:08 +0100 |
commit | 35e61e8827ee8ea09e6093ab4d8ba45efd537e36 (patch) | |
tree | 909bd0b20f32458071763e5957f140c665b8ac5f | |
parent | riscv: select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY (diff) | |
download | linux-35e61e8827ee8ea09e6093ab4d8ba45efd537e36.tar.xz linux-35e61e8827ee8ea09e6093ab4d8ba45efd537e36.zip |
riscv: ftrace: Make function graph use ftrace directly
Similar to commit 0c0593b45c9b ("x86/ftrace: Make function graph use
ftrace directly") and commit c4a0ebf87ceb ("arm64/ftrace: Make
function graph use ftrace directly"), RISC-V has no need for a special
graph tracer hook. The graph_ops::func function can be used to install
the return_hooker.
This cleanup only changes the FTRACE_WITH_REGS implementation, leaving
the mcount-based implementation is unaffected.
Perform the simplification, and also cleanup the register save/restore
macros.
Signed-off-by: Song Shuai <suagrfillet@gmail.com>
Tested-by: Guo Ren <guoren@kernel.org>
Signed-off-by: Guo Ren <guoren@kernel.org>
Acked-by: Björn Töpel <bjorn@rivosinc.com>
Link: https://lore.kernel.org/r/20231130121531.1178502-3-bjorn@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
-rw-r--r-- | arch/riscv/include/asm/ftrace.h | 11 | ||||
-rw-r--r-- | arch/riscv/kernel/ftrace.c | 30 | ||||
-rw-r--r-- | arch/riscv/kernel/mcount-dyn.S | 190 |
3 files changed, 175 insertions, 56 deletions
diff --git a/arch/riscv/include/asm/ftrace.h b/arch/riscv/include/asm/ftrace.h index 2b2f5df7ef2c..b383926f73be 100644 --- a/arch/riscv/include/asm/ftrace.h +++ b/arch/riscv/include/asm/ftrace.h @@ -128,7 +128,16 @@ do { \ struct dyn_ftrace; int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec); #define ftrace_init_nop ftrace_init_nop -#endif + +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS +struct ftrace_ops; +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 +#endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */ + +#endif /* __ASSEMBLY__ */ #endif /* CONFIG_DYNAMIC_FTRACE */ diff --git a/arch/riscv/kernel/ftrace.c b/arch/riscv/kernel/ftrace.c index 03a6434a8cdd..f5aa24d9e1c1 100644 --- a/arch/riscv/kernel/ftrace.c +++ b/arch/riscv/kernel/ftrace.c @@ -178,32 +178,28 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr, } #ifdef CONFIG_DYNAMIC_FTRACE +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS +void ftrace_graph_func(unsigned long ip, unsigned long parent_ip, + struct ftrace_ops *op, struct ftrace_regs *fregs) +{ + struct pt_regs *regs = arch_ftrace_get_regs(fregs); + unsigned long *parent = (unsigned long *)®s->ra; + + prepare_ftrace_return(parent, ip, frame_pointer(regs)); +} +#else /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */ extern void ftrace_graph_call(void); -extern void ftrace_graph_regs_call(void); int ftrace_enable_ftrace_graph_caller(void) { - int ret; - - ret = __ftrace_modify_call((unsigned long)&ftrace_graph_call, - (unsigned long)&prepare_ftrace_return, true, true); - if (ret) - return ret; - - return __ftrace_modify_call((unsigned long)&ftrace_graph_regs_call, + return __ftrace_modify_call((unsigned long)&ftrace_graph_call, (unsigned long)&prepare_ftrace_return, true, true); } int ftrace_disable_ftrace_graph_caller(void) { - int ret; - - ret = __ftrace_modify_call((unsigned long)&ftrace_graph_call, - (unsigned long)&prepare_ftrace_return, false, true); - if (ret) - return ret; - - return __ftrace_modify_call((unsigned long)&ftrace_graph_regs_call, + return __ftrace_modify_call((unsigned long)&ftrace_graph_call, (unsigned long)&prepare_ftrace_return, false, true); } +#endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */ #endif /* CONFIG_DYNAMIC_FTRACE */ #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ diff --git a/arch/riscv/kernel/mcount-dyn.S b/arch/riscv/kernel/mcount-dyn.S index 58dd96a2a153..c902a7ddb310 100644 --- a/arch/riscv/kernel/mcount-dyn.S +++ b/arch/riscv/kernel/mcount-dyn.S @@ -57,31 +57,150 @@ .endm #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS - .macro SAVE_ALL + +/** +* SAVE_ABI_REGS - save regs against the pt_regs struct +* +* @all: tell if saving all the regs +* +* If all is set, all the regs will be saved, otherwise only ABI +* related regs (a0-a7,epc,ra and optional s0) will be saved. +* +* After the stack is established, +* +* 0(sp) stores the PC of the traced function which can be accessed +* by &(fregs)->regs->epc in tracing function. Note that the real +* function entry address should be computed with -FENTRY_RA_OFFSET. +* +* 8(sp) stores the function return address (i.e. parent IP) that +* can be accessed by &(fregs)->regs->ra in tracing function. +* +* The other regs are saved at the respective localtion and accessed +* by the respective pt_regs member. +* +* Here is the layout of stack for your reference. +* +* PT_SIZE_ON_STACK -> +++++++++ +* + ..... + +* + t3-t6 + +* + s2-s11+ +* + a0-a7 + --++++-> ftrace_caller saved +* + s1 + + +* + s0 + --+ +* + t0-t2 + + +* + tp + + +* + gp + + +* + sp + + +* + ra + --+ // parent IP +* sp -> + epc + --+ // PC +* +++++++++ +**/ + .macro SAVE_ABI_REGS, all=0 addi sp, sp, -PT_SIZE_ON_STACK - REG_S t0, PT_EPC(sp) - REG_S x1, PT_RA(sp) - REG_S x2, PT_SP(sp) - REG_S x3, PT_GP(sp) - REG_S x4, PT_TP(sp) - REG_S x5, PT_T0(sp) - save_from_x6_to_x31 + REG_S t0, PT_EPC(sp) + REG_S x1, PT_RA(sp) + + // save the ABI regs + + REG_S x10, PT_A0(sp) + REG_S x11, PT_A1(sp) + REG_S x12, PT_A2(sp) + REG_S x13, PT_A3(sp) + REG_S x14, PT_A4(sp) + REG_S x15, PT_A5(sp) + REG_S x16, PT_A6(sp) + REG_S x17, PT_A7(sp) + + // save the leftover regs + + .if \all == 1 + REG_S x2, PT_SP(sp) + REG_S x3, PT_GP(sp) + REG_S x4, PT_TP(sp) + REG_S x5, PT_T0(sp) + REG_S x6, PT_T1(sp) + REG_S x7, PT_T2(sp) + REG_S x8, PT_S0(sp) + REG_S x9, PT_S1(sp) + REG_S x18, PT_S2(sp) + REG_S x19, PT_S3(sp) + REG_S x20, PT_S4(sp) + REG_S x21, PT_S5(sp) + REG_S x22, PT_S6(sp) + REG_S x23, PT_S7(sp) + REG_S x24, PT_S8(sp) + REG_S x25, PT_S9(sp) + REG_S x26, PT_S10(sp) + REG_S x27, PT_S11(sp) + REG_S x28, PT_T3(sp) + REG_S x29, PT_T4(sp) + REG_S x30, PT_T5(sp) + REG_S x31, PT_T6(sp) + + // save s0 if FP_TEST defined + + .else +#ifdef HAVE_FUNCTION_GRAPH_FP_TEST + REG_S x8, PT_S0(sp) +#endif + .endif .endm - .macro RESTORE_ALL - REG_L x1, PT_RA(sp) - REG_L x2, PT_SP(sp) - REG_L x3, PT_GP(sp) - REG_L x4, PT_TP(sp) - /* Restore t0 with PT_EPC */ - REG_L x5, PT_EPC(sp) - restore_from_x6_to_x31 - + .macro RESTORE_ABI_REGS, all=0 + REG_L t0, PT_EPC(sp) + REG_L x1, PT_RA(sp) + REG_L x10, PT_A0(sp) + REG_L x11, PT_A1(sp) + REG_L x12, PT_A2(sp) + REG_L x13, PT_A3(sp) + REG_L x14, PT_A4(sp) + REG_L x15, PT_A5(sp) + REG_L x16, PT_A6(sp) + REG_L x17, PT_A7(sp) + + .if \all == 1 + REG_L x2, PT_SP(sp) + REG_L x3, PT_GP(sp) + REG_L x4, PT_TP(sp) + REG_L x6, PT_T1(sp) + REG_L x7, PT_T2(sp) + REG_L x8, PT_S0(sp) + REG_L x9, PT_S1(sp) + REG_L x18, PT_S2(sp) + REG_L x19, PT_S3(sp) + REG_L x20, PT_S4(sp) + REG_L x21, PT_S5(sp) + REG_L x22, PT_S6(sp) + REG_L x23, PT_S7(sp) + REG_L x24, PT_S8(sp) + REG_L x25, PT_S9(sp) + REG_L x26, PT_S10(sp) + REG_L x27, PT_S11(sp) + REG_L x28, PT_T3(sp) + REG_L x29, PT_T4(sp) + REG_L x30, PT_T5(sp) + REG_L x31, PT_T6(sp) + + .else +#ifdef HAVE_FUNCTION_GRAPH_FP_TEST + REG_L x8, PT_S0(sp) +#endif + .endif addi sp, sp, PT_SIZE_ON_STACK .endm + + .macro PREPARE_ARGS + addi a0, t0, -FENTRY_RA_OFFSET + la a1, function_trace_op + REG_L a2, 0(a1) + mv a1, ra + mv a3, sp + .endm + #endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */ +#ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS SYM_FUNC_START(ftrace_caller) SAVE_ABI @@ -105,34 +224,29 @@ SYM_INNER_LABEL(ftrace_graph_call, SYM_L_GLOBAL) call ftrace_stub #endif RESTORE_ABI - jr t0 + jr t0 SYM_FUNC_END(ftrace_caller) -#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS +#else /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */ SYM_FUNC_START(ftrace_regs_caller) - SAVE_ALL - - addi a0, t0, -FENTRY_RA_OFFSET - la a1, function_trace_op - REG_L a2, 0(a1) - mv a1, ra - mv a3, sp + SAVE_ABI_REGS 1 + PREPARE_ARGS SYM_INNER_LABEL(ftrace_regs_call, SYM_L_GLOBAL) call ftrace_stub -#ifdef CONFIG_FUNCTION_GRAPH_TRACER - addi a0, sp, PT_RA - REG_L a1, PT_EPC(sp) - addi a1, a1, -FENTRY_RA_OFFSET -#ifdef HAVE_FUNCTION_GRAPH_FP_TEST - mv a2, s0 -#endif -SYM_INNER_LABEL(ftrace_graph_regs_call, SYM_L_GLOBAL) + RESTORE_ABI_REGS 1 + jr t0 +SYM_FUNC_END(ftrace_regs_caller) + +SYM_FUNC_START(ftrace_caller) + SAVE_ABI_REGS 0 + PREPARE_ARGS + +SYM_INNER_LABEL(ftrace_call, SYM_L_GLOBAL) call ftrace_stub -#endif - RESTORE_ALL - jr t0 -SYM_FUNC_END(ftrace_regs_caller) + RESTORE_ABI_REGS 0 + jr t0 +SYM_FUNC_END(ftrace_caller) #endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */ |