Messages in this thread Patch in this message | | | From | Florent Revest <> | Subject | [PATCH 5/8] ftrace: Make DIRECT_CALLS work WITH_ARGS and !WITH_REGS | Date | Wed, 1 Feb 2023 17:34:17 +0100 |
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Direct called trampolines can be called in two ways: - either from the ftrace callsite. In this case, they do not access any struct ftrace_regs nor pt_regs - Or, if a ftrace ops is also attached, from the end of a ftrace trampoline. In this case, the call_direct_funcs ops is in charge of setting the direct call trampoline's address in a struct ftrace_regs
Since "ftrace: pass fregs to arch_ftrace_set_direct_caller()", the later case no longer requires a full pt_regs. It only needs a struct ftrace_regs so DIRECT_CALLS can work with both WITH_ARGS or WITH_REGS. With architectures like arm64 already abandoning WITH_REGS in favor of WITH_ARGS, it's important to have DIRECT_CALLS work WITH_ARGS only.
Signed-off-by: Florent Revest <revest@chromium.org> --- kernel/trace/Kconfig | 2 +- kernel/trace/ftrace.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 5df427a2321d..4496a7c69810 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -257,7 +257,7 @@ config DYNAMIC_FTRACE_WITH_REGS config DYNAMIC_FTRACE_WITH_DIRECT_CALLS def_bool y - depends on DYNAMIC_FTRACE_WITH_REGS + depends on DYNAMIC_FTRACE_WITH_REGS || DYNAMIC_FTRACE_WITH_ARGS depends on HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS config DYNAMIC_FTRACE_WITH_CALL_OPS diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index b0426de11c45..73b6f6489ba1 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -5282,7 +5282,7 @@ static LIST_HEAD(ftrace_direct_funcs); static int register_ftrace_function_nolock(struct ftrace_ops *ops); -#define MULTI_FLAGS (FTRACE_OPS_FL_DIRECT | FTRACE_OPS_FL_SAVE_REGS) +#define MULTI_FLAGS (FTRACE_OPS_FL_DIRECT) static int check_direct_multi(struct ftrace_ops *ops) { -- 2.39.1.519.gcb327c4b5f-goog
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