Messages in this thread Patch in this message |  | | From | Chengming Zhou <> | Subject | [PATCH v4 2/2] arm64/ftrace: Make function graph use ftrace directly | Date | Sat, 9 Apr 2022 23:35:54 +0800 |
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As we do in commit 0c0593b45c9b ("x86/ftrace: Make function graph use ftrace directly"), we don't need special hook for graph tracer, but instead we use graph_ops:func function to install return_hooker.
Since commit 3b23e4991fb6 ("arm64: implement ftrace with regs") add implementation for FTRACE_WITH_REGS on arm64, we can easily adopt the same cleanup on arm64.
And this cleanup only changes the FTRACE_WITH_REGS implementation, so the mcount-based implementation is unaffected.
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com> --- v3: - Add comments in ftrace_graph_func() as suggested by Steve. Thanks.
v2: - Remove FTRACE_WITH_REGS ftrace_graph_caller asm, thanks Mark. --- arch/arm64/include/asm/ftrace.h | 7 +++++++ arch/arm64/kernel/entry-ftrace.S | 17 ----------------- arch/arm64/kernel/ftrace.c | 17 +++++++++++++++++ 3 files changed, 24 insertions(+), 17 deletions(-)
diff --git a/arch/arm64/include/asm/ftrace.h b/arch/arm64/include/asm/ftrace.h index 1494cfa8639b..dbc45a4157fa 100644 --- a/arch/arm64/include/asm/ftrace.h +++ b/arch/arm64/include/asm/ftrace.h @@ -80,8 +80,15 @@ static inline unsigned long ftrace_call_adjust(unsigned long addr) #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS struct dyn_ftrace; +struct ftrace_ops; +struct ftrace_regs; + int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec); #define ftrace_init_nop ftrace_init_nop + +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 #define ftrace_return_address(n) return_address(n) diff --git a/arch/arm64/kernel/entry-ftrace.S b/arch/arm64/kernel/entry-ftrace.S index e535480a4069..d42a205ef625 100644 --- a/arch/arm64/kernel/entry-ftrace.S +++ b/arch/arm64/kernel/entry-ftrace.S @@ -97,12 +97,6 @@ SYM_CODE_START(ftrace_common) SYM_INNER_LABEL(ftrace_call, SYM_L_GLOBAL) bl ftrace_stub -#ifdef CONFIG_FUNCTION_GRAPH_TRACER -SYM_INNER_LABEL(ftrace_graph_call, SYM_L_GLOBAL) // ftrace_graph_caller(); - nop // If enabled, this will be replaced - // "b ftrace_graph_caller" -#endif - /* * At the callsite x0-x8 and x19-x30 were live. Any C code will have preserved * x19-x29 per the AAPCS, and we created frame records upon entry, so we need @@ -127,17 +121,6 @@ ftrace_common_return: ret x9 SYM_CODE_END(ftrace_common) -#ifdef CONFIG_FUNCTION_GRAPH_TRACER -SYM_CODE_START(ftrace_graph_caller) - ldr x0, [sp, #S_PC] - sub x0, x0, #AARCH64_INSN_SIZE // ip (callsite's BL insn) - add x1, sp, #S_LR // parent_ip (callsite's LR) - ldr x2, [sp, #PT_REGS_SIZE] // parent fp (callsite's FP) - bl prepare_ftrace_return - b ftrace_common_return -SYM_CODE_END(ftrace_graph_caller) -#endif - #else /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */ /* diff --git a/arch/arm64/kernel/ftrace.c b/arch/arm64/kernel/ftrace.c index 4506c4a90ac1..35eb7c9b5e53 100644 --- a/arch/arm64/kernel/ftrace.c +++ b/arch/arm64/kernel/ftrace.c @@ -268,6 +268,22 @@ void prepare_ftrace_return(unsigned long self_addr, unsigned long *parent, } #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) +{ + /* + * Athough graph_ops doesn't have FTRACE_OPS_FL_SAVE_REGS set in flags, + * regs can't be NULL in DYNAMIC_FTRACE_WITH_REGS. By design, it should + * be fixed when DYNAMIC_FTRACE_WITH_ARGS is implemented. + */ + struct pt_regs *regs = arch_ftrace_get_regs(fregs); + unsigned long *parent = (unsigned long *)&procedure_link_pointer(regs); + + prepare_ftrace_return(ip, parent, frame_pointer(regs)); +} +#else /* * Turn on/off the call to ftrace_graph_caller() in ftrace_caller() * depending on @enable. @@ -297,5 +313,6 @@ int ftrace_disable_ftrace_graph_caller(void) { return ftrace_modify_graph_caller(false); } +#endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */ #endif /* CONFIG_DYNAMIC_FTRACE */ #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ -- 2.35.1
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