[PATCH v4 3/9] tracing: Expose ftrace_regs regardless of CONFIG_FUNCTION_TRACER
From: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Date: 2023-08-23 15:18:09
Also in:
bpf, lkml
Subsystem:
function hooks (ftrace), s390 architecture, the rest · Maintainers:
Steven Rostedt, Masami Hiramatsu, Heiko Carstens, Vasily Gorbik, Alexander Gordeev, 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>
Acked-by: Florent Revest <redacted>
---
Changes in v3:
- arch/s390/include/asm/ftrace.h: hide ftrace_regs parts if
CONFIG_FUNCTION_TRACER=n to avoid conflict.
- Fixed typo.
- Define accessor macros only if HAVE_REGS_AND_STACK_ACCESS_API=y
---
arch/s390/include/asm/ftrace.h | 4 +++
include/linux/ftrace.h | 51 +++++++++++++++++++++++-----------------
2 files changed, 33 insertions(+), 22 deletions(-)
diff --git a/arch/s390/include/asm/ftrace.h b/arch/s390/include/asm/ftrace.h
index e5c5cb1207e2..74cd2e8bf660 100644
--- a/arch/s390/include/asm/ftrace.h
+++ b/arch/s390/include/asm/ftrace.h@@ -41,6 +41,8 @@ static inline unsigned long ftrace_call_adjust(unsigned long addr) return addr; } +#ifdef CONFIG_FUNCTION_TRACER + struct ftrace_regs { struct pt_regs regs; };
@@ -80,6 +82,8 @@ ftrace_regs_set_instruction_pointer(struct ftrace_regs *fregs, #define ftrace_regs_query_register_offset(name) \ regs_query_register_offset(name) +#endif /* CONFIG_FUNCTION_TRACER */ + #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS /* * When an ftrace registered caller is tracing a function that is
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index aad9cf8876b5..fe335d861f08 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h@@ -112,24 +112,44 @@ 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 disables 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; }; #define arch_ftrace_get_regs(fregs) (&(fregs)->regs) +#ifdef CONFIG_HAVE_REGS_AND_STACK_ACCESS_API + /* * ftrace_regs_set_instruction_pointer() is to be defined by the architecture * if to allow setting of the instruction pointer from the ftrace_regs when * HAVE_DYNAMIC_FTRACE_WITH_ARGS is set and it supports live kernel patching. */ #define ftrace_regs_set_instruction_pointer(fregs, ip) do { } while (0) -#endif /* 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 /* CONFIG_HAVE_REGS_AND_STACK_ACCESS_API */ + +#endif /* !CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS || !CONFIG_FUNCTION_TRACER */ static __always_inline struct pt_regs *ftrace_get_regs(struct ftrace_regs *fregs) {
@@ -151,22 +171,9 @@ 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);