From: Florent Revest <revest@chromium.org>
To: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org
Cc: rostedt@goodmis.org, mhiramat@kernel.org, mark.rutland@arm.com,
ast@kernel.org, daniel@iogearbox.net, kpsingh@kernel.org,
revest@chromium.org, jolsa@kernel.org
Subject: [PATCH v2 6/7] ftrace: Make DIRECT_CALLS work WITH_ARGS and !WITH_REGS
Date: Tue, 21 Mar 2023 15:04:23 +0100 [thread overview]
Message-ID: <20230321140424.345218-7-revest@chromium.org> (raw)
In-Reply-To: <20230321140424.345218-1-revest@chromium.org>
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:
commit 9705bc709604 ("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>
Co-developed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
---
include/linux/ftrace.h | 6 ++++++
kernel/trace/Kconfig | 2 +-
kernel/trace/ftrace.c | 2 +-
3 files changed, 8 insertions(+), 2 deletions(-)
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 6a532dd6789e..31f1e1df2af3 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -241,6 +241,12 @@ enum {
FTRACE_OPS_FL_DIRECT = BIT(17),
};
+#ifndef CONFIG_DYNAMIC_FTRACE_WITH_ARGS
+#define FTRACE_OPS_FL_SAVE_ARGS FTRACE_OPS_FL_SAVE_REGS
+#else
+#define FTRACE_OPS_FL_SAVE_ARGS 0
+#endif
+
/*
* FTRACE_OPS_CMD_* commands allow the ftrace core logic to request changes
* to a ftrace_ops. Note, the requests may fail.
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index a856d4a34c67..5b1e7fa41ca8 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 bf1f857bfe76..437ae55a9f51 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -5287,7 +5287,7 @@ 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 | FTRACE_OPS_FL_SAVE_ARGS)
static int check_direct_multi(struct ftrace_ops *ops)
{
--
2.40.0.rc2.332.ga46443480c-goog
next prev parent reply other threads:[~2023-03-21 14:05 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-21 14:04 [PATCH v2 0/7] Refactor ftrace direct call APIs Florent Revest
2023-03-21 14:04 ` [PATCH v2 1/7] ftrace: Let unregister_ftrace_direct_multi() call ftrace_free_filter() Florent Revest
2023-03-21 14:04 ` [PATCH v2 2/7] ftrace: Replace uses of _ftrace_direct APIs with _ftrace_direct_multi Florent Revest
2023-03-21 14:04 ` [PATCH v2 3/7] ftrace: Remove the legacy _ftrace_direct API Florent Revest
2023-03-21 14:04 ` [PATCH v2 4/7] ftrace: Rename _ftrace_direct_multi APIs to _ftrace_direct APIs Florent Revest
2023-03-21 14:04 ` [PATCH v2 5/7] ftrace: Store direct called addresses in their ops Florent Revest
2023-03-21 14:04 ` Florent Revest [this message]
2023-03-21 14:04 ` [PATCH v2 7/7] ftrace: selftest: remove broken trace_direct_tramp Florent Revest
2023-03-21 17:06 ` [PATCH v2 0/7] Refactor ftrace direct call APIs Jiri Olsa
2023-03-23 23:43 ` Steven Rostedt
2023-03-24 2:00 ` Steven Rostedt
2023-03-24 11:46 ` Mark Rutland
2023-03-24 17:18 ` Florent Revest
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