From 9705bc70960459ae09f4a5e77283973bb3a40f57 Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Thu, 3 Nov 2022 17:05:17 +0000 Subject: ftrace: pass fregs to arch_ftrace_set_direct_caller() In subsequent patches we'll arrange for architectures to have an ftrace_regs which is entirely distinct from pt_regs. In preparation for this, we need to minimize the use of pt_regs to where strictly necessary in the core ftrace code. This patch changes the prototype of arch_ftrace_set_direct_caller() to take ftrace_regs rather than pt_regs, and moves the extraction of the pt_regs into arch_ftrace_set_direct_caller(). On x86, arch_ftrace_set_direct_caller() can be used even when CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS=n, and defines struct ftrace_regs. Due to this, it's necessary to define arch_ftrace_set_direct_caller() as a macro to avoid using an incomplete type. I've also moved the body of arch_ftrace_set_direct_caller() after the CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS=y defineidion of struct ftrace_regs. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland Cc: Florent Revest Cc: Masami Hiramatsu Cc: Steven Rostedt Reviewed-by: Masami Hiramatsu (Google) Reviewed-by: Steven Rostedt (Google) Link: https://lore.kernel.org/r/20221103170520.931305-2-mark.rutland@arm.com Signed-off-by: Will Deacon --- include/linux/ftrace.h | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) (limited to 'include/linux') diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 62557d4bffc2..f201fcbfffb0 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -37,9 +37,10 @@ extern void ftrace_boot_snapshot(void); static inline void ftrace_boot_snapshot(void) { } #endif -#ifdef CONFIG_FUNCTION_TRACER struct ftrace_ops; struct ftrace_regs; + +#ifdef CONFIG_FUNCTION_TRACER /* * If the arch's mcount caller does not support all of ftrace's * features, then it must call an indirect function that @@ -427,9 +428,7 @@ static inline int modify_ftrace_direct_multi_nolock(struct ftrace_ops *ops, unsi { return -ENODEV; } -#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ -#ifndef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS /* * This must be implemented by the architecture. * It is the way the ftrace direct_ops helper, when called @@ -443,9 +442,9 @@ static inline int modify_ftrace_direct_multi_nolock(struct ftrace_ops *ops, unsi * the return from the trampoline jump to the direct caller * instead of going back to the function it just traced. */ -static inline void arch_ftrace_set_direct_caller(struct pt_regs *regs, +static inline void arch_ftrace_set_direct_caller(struct ftrace_regs *fregs, unsigned long addr) { } -#endif /* CONFIG_HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ +#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ #ifdef CONFIG_STACK_TRACER -- cgit v1.2.3 From 0ef86097f127d0d73e19aa4dcf86106105e7db09 Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Thu, 3 Nov 2022 17:05:18 +0000 Subject: ftrace: rename ftrace_instruction_pointer_set() -> ftrace_regs_set_instruction_pointer() In subsequent patches we'll add a sew of ftrace_regs_{get,set}_*() helpers. In preparation, this patch renames ftrace_instruction_pointer_set() to ftrace_regs_set_instruction_pointer(). There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland Cc: Florent Revest Cc: Masami Hiramatsu Cc: Steven Rostedt Reviewed-by: Masami Hiramatsu (Google) Reviewed-by: Steven Rostedt (Google) Link: https://lore.kernel.org/r/20221103170520.931305-3-mark.rutland@arm.com Signed-off-by: Will Deacon --- include/linux/ftrace.h | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) (limited to 'include/linux') diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index f201fcbfffb0..ec3657a60f85 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -111,12 +111,11 @@ struct ftrace_regs { #define arch_ftrace_get_regs(fregs) (&(fregs)->regs) /* - * ftrace_instruction_pointer_set() 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. + * 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_instruction_pointer_set(fregs, ip) do { } while (0) +#define ftrace_regs_set_instruction_pointer(fregs, ip) do { } while (0) #endif /* CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS */ static __always_inline struct pt_regs *ftrace_get_regs(struct ftrace_regs *fregs) -- cgit v1.2.3 From 94d095ffa0e16bb7f161a2b73bbe5c2795d499a8 Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Thu, 3 Nov 2022 17:05:19 +0000 Subject: ftrace: abstract DYNAMIC_FTRACE_WITH_ARGS accesses In subsequent patches we'll arrange for architectures to have an ftrace_regs which is entirely distinct from pt_regs. In preparation for this, we need to minimize the use of pt_regs to where strictly necessary in the core ftrace code. This patch adds new ftrace_regs_{get,set}_*() helpers which can be used to manipulate ftrace_regs. When CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS=y, these can always be used on any ftrace_regs, and when CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS=n these can be used when regs are available. A new ftrace_regs_has_args(fregs) helper is added which code can use to check when these are usable. Co-developed-by: Florent Revest Signed-off-by: Florent Revest Signed-off-by: Mark Rutland Cc: Masami Hiramatsu Cc: Steven Rostedt Reviewed-by: Masami Hiramatsu (Google) Reviewed-by: Steven Rostedt (Google) Link: https://lore.kernel.org/r/20221103170520.931305-4-mark.rutland@arm.com Signed-off-by: Will Deacon --- include/linux/ftrace.h | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) (limited to 'include/linux') diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index ec3657a60f85..99f1146614c0 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -126,6 +126,35 @@ static __always_inline struct pt_regs *ftrace_get_regs(struct ftrace_regs *fregs return arch_ftrace_get_regs(fregs); } +/* + * When true, the ftrace_regs_{get,set}_*() functions may be used on fregs. + * Note: this can be true even when ftrace_get_regs() cannot provide a pt_regs. + */ +static __always_inline bool ftrace_regs_has_args(struct ftrace_regs *fregs) +{ + if (IS_ENABLED(CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS)) + return true; + + 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 + typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *op, struct ftrace_regs *fregs); -- cgit v1.2.3