[RFC PATCH v2 2/6] tracing: Expose ftrace_regs regardless of CONFIG_FUNCTION_TRACER
From: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Date: 2023-08-07 06:49:03
Also in:
bpf, lkml
Subsystem:
function hooks (ftrace), the rest · Maintainers:
Steven Rostedt, Masami Hiramatsu, Linus Torvalds
From: Masami Hiramatsu (Google) <mhiramat@kernel.org> In order to be able to use ftrace_regs even from features unrelated to function tracer (e.g. kretprobe), expose ftrace_regs structures and APIs even if the CONFIG_FUNCTION_TRACER=n. Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> --- include/linux/ftrace.h | 45 ++++++++++++++++++++++++--------------------- 1 file changed, 24 insertions(+), 21 deletions(-)
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index ce156c7704ee..3fb94a1a2461 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h@@ -112,11 +112,11 @@ static inline int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *val } #endif -#ifdef CONFIG_FUNCTION_TRACER - -extern int ftrace_enabled; - -#ifndef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS +/* + * If the architecture doesn't support FTRACE_WITH_ARGS or disable function + * tracer, define the default(pt_regs compatible) ftrace_regs. + */ +#if !defined(CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS) || !defined(CONFIG_FUNCTION_TRACER) struct ftrace_regs { struct pt_regs regs;
@@ -129,6 +129,22 @@ struct ftrace_regs { * HAVE_DYNAMIC_FTRACE_WITH_ARGS is set and it supports live kernel patching. */ #define ftrace_regs_set_instruction_pointer(fregs, ip) do { } while (0) + +#define ftrace_regs_get_instruction_pointer(fregs) \ + instruction_pointer(ftrace_get_regs(fregs)) +#define ftrace_regs_get_argument(fregs, n) \ + regs_get_kernel_argument(ftrace_get_regs(fregs), n) +#define ftrace_regs_get_stack_pointer(fregs) \ + kernel_stack_pointer(ftrace_get_regs(fregs)) +#define ftrace_regs_return_value(fregs) \ + regs_return_value(ftrace_get_regs(fregs)) +#define ftrace_regs_set_return_value(fregs, ret) \ + regs_set_return_value(ftrace_get_regs(fregs), ret) +#define ftrace_override_function_with_return(fregs) \ + override_function_with_return(ftrace_get_regs(fregs)) +#define ftrace_regs_query_register_offset(name) \ + regs_query_register_offset(name) + #endif /* CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS */ static __always_inline struct pt_regs *ftrace_get_regs(struct ftrace_regs *fregs)
@@ -151,22 +167,9 @@ static __always_inline bool ftrace_regs_has_args(struct ftrace_regs *fregs) return ftrace_get_regs(fregs) != NULL; } -#ifndef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS -#define ftrace_regs_get_instruction_pointer(fregs) \ - instruction_pointer(ftrace_get_regs(fregs)) -#define ftrace_regs_get_argument(fregs, n) \ - regs_get_kernel_argument(ftrace_get_regs(fregs), n) -#define ftrace_regs_get_stack_pointer(fregs) \ - kernel_stack_pointer(ftrace_get_regs(fregs)) -#define ftrace_regs_return_value(fregs) \ - regs_return_value(ftrace_get_regs(fregs)) -#define ftrace_regs_set_return_value(fregs, ret) \ - regs_set_return_value(ftrace_get_regs(fregs), ret) -#define ftrace_override_function_with_return(fregs) \ - override_function_with_return(ftrace_get_regs(fregs)) -#define ftrace_regs_query_register_offset(name) \ - regs_query_register_offset(name) -#endif +#ifdef CONFIG_FUNCTION_TRACER + +extern int ftrace_enabled; typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *op, struct ftrace_regs *fregs);