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authorSteven Rostedt <rostedt@goodmis.org>2025-07-04 10:48:38 -0400
committerSteven Rostedt (Google) <rostedt@goodmis.org>2025-07-22 20:15:56 -0400
commit4d6d0a6263babf7c43faa55de4fa3c6637dec624 (patch)
tree17c2a7509f4ddd4c9844a65750bb44b899a2b6c7 /kernel
parent9b4d5d330fcd40bbc38a1e6ed3d617e674d651fa (diff)
tracing: Remove redundant config HAVE_FTRACE_MCOUNT_RECORD
Ftrace is tightly coupled with architecture specific code because it requires the use of trampolines written in assembly. This means that when a new feature or optimization is made, it must be done for all architectures. To simplify the approach, CONFIG_HAVE_FTRACE_* configs are added to denote which architecture has the new enhancement so that other architectures can still function until they too have been updated. The CONFIG_HAVE_FTRACE_MCOUNT was added to help simplify the DYNAMIC_FTRACE work, but now every architecture that implements DYNAMIC_FTRACE also has HAVE_FTRACE_MCOUNT set too, making it redundant with the HAVE_DYNAMIC_FTRACE. Remove the HAVE_FTRACE_MCOUNT config and use DYNAMIC_FTRACE directly where applicable. Link: https://lore.kernel.org/all/20250703154916.48e3ada7@gandalf.local.home/ Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/20250704104838.27a18690@gandalf.local.home Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/module/main.c2
-rw-r--r--kernel/trace/Kconfig18
-rw-r--r--kernel/trace/ftrace.c4
3 files changed, 5 insertions, 19 deletions
diff --git a/kernel/module/main.c b/kernel/module/main.c
index 413ac6ea3702..58d36f8cef0d 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -2639,7 +2639,7 @@ static int find_module_sections(struct module *mod, struct load_info *info)
sizeof(*mod->trace_bprintk_fmt_start),
&mod->num_trace_bprintk_fmt);
#endif
-#ifdef CONFIG_FTRACE_MCOUNT_RECORD
+#ifdef CONFIG_DYNAMIC_FTRACE
/* sechdrs[0].sh_size is always zero */
mod->ftrace_callsites = section_objs(info, FTRACE_CALLSITE_SECTION,
sizeof(*mod->ftrace_callsites),
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 28afc6941e7a..9f2b1661a8ac 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -74,11 +74,6 @@ config HAVE_DYNAMIC_FTRACE_NO_PATCHABLE
If the architecture generates __patchable_function_entries sections
but does not want them included in the ftrace locations.
-config HAVE_FTRACE_MCOUNT_RECORD
- bool
- help
- See Documentation/trace/ftrace-design.rst
-
config HAVE_SYSCALL_TRACEPOINTS
bool
help
@@ -803,27 +798,22 @@ config BPF_KPROBE_OVERRIDE
Allows BPF to override the execution of a probed function and
set a different return value. This is used for error injection.
-config FTRACE_MCOUNT_RECORD
- def_bool y
- depends on DYNAMIC_FTRACE
- depends on HAVE_FTRACE_MCOUNT_RECORD
-
config FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY
bool
- depends on FTRACE_MCOUNT_RECORD
+ depends on DYNAMIC_FTRACE
config FTRACE_MCOUNT_USE_CC
def_bool y
depends on $(cc-option,-mrecord-mcount)
depends on !FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY
- depends on FTRACE_MCOUNT_RECORD
+ depends on DYNAMIC_FTRACE
config FTRACE_MCOUNT_USE_OBJTOOL
def_bool y
depends on HAVE_OBJTOOL_MCOUNT
depends on !FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY
depends on !FTRACE_MCOUNT_USE_CC
- depends on FTRACE_MCOUNT_RECORD
+ depends on DYNAMIC_FTRACE
select OBJTOOL
config FTRACE_MCOUNT_USE_RECORDMCOUNT
@@ -831,7 +821,7 @@ config FTRACE_MCOUNT_USE_RECORDMCOUNT
depends on !FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY
depends on !FTRACE_MCOUNT_USE_CC
depends on !FTRACE_MCOUNT_USE_OBJTOOL
- depends on FTRACE_MCOUNT_RECORD
+ depends on DYNAMIC_FTRACE
config TRACING_MAP
bool
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 4203fad56b6c..00b76d450a89 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1042,10 +1042,6 @@ static struct ftrace_ops *removed_ops;
*/
static bool update_all_ops;
-#ifndef CONFIG_FTRACE_MCOUNT_RECORD
-# error Dynamic ftrace depends on MCOUNT_RECORD
-#endif
-
struct ftrace_func_probe {
struct ftrace_probe_ops *probe_ops;
struct ftrace_ops ops;