ftrace: Synchronize the initialization of ftrace_opsgrafted

There's some internal state that ftrace_ops needs to have set, but since
it can be declared outside of the ftrace.c code, it calls
ftrace_ops_init() on the ops in every global function. The issue is that
if two tasks call it on the same ops at the same time it is possible to
have the initialization of one corrupt the initialization of the other
call.

Create a ops_mutex to use to synchronize every initialization of the
ftrace_ops. The mutex is taken within checking the ftrace_ops flag that
states it was initializied but the flag is checked again after the mutex
has been taken. Checking first outside the mutex allows it to shortcut
having to take the mutex. But then the check needs to be done again after
the mute is taken in case of races.

Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home
Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock")
Reported-by: sashiko-bot@kernel.org
Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 76 insertions, 0 deletions

diff --git a/tools/perf/util/block-info.h b/tools/perf/util/block-info.h
new file mode 100644
index 000000000..b9329dc3a
--- /dev/null
+++ b/tools/perf/util/block-info.h
@@ -0,0 +1,76 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __PERF_BLOCK_H
+#define __PERF_BLOCK_H
+
+#include <linux/types.h>
+#include "hist.h"
+#include "symbol.h"
+#include "sort.h"
+#include "ui/ui.h"
+
+struct block_info {
+	struct symbol		*sym;
+	u64			start;
+	u64			end;
+	u64			cycles;
+	u64			cycles_aggr;
+	s64			cycles_spark[NUM_SPARKS];
+	u64			total_cycles;
+	int			num;
+	int			num_aggr;
+	int			br_cntr_nr;
+	u64			*br_cntr;
+	struct evsel		*evsel;
+};
+
+struct block_fmt {
+	struct perf_hpp_fmt	fmt;
+	int			idx;
+	int			width;
+	const char		*header;
+	u64			total_cycles;
+	u64			block_cycles;
+};
+
+enum {
+	PERF_HPP_REPORT__BLOCK_TOTAL_CYCLES_PCT,
+	PERF_HPP_REPORT__BLOCK_LBR_CYCLES,
+	PERF_HPP_REPORT__BLOCK_CYCLES_PCT,
+	PERF_HPP_REPORT__BLOCK_AVG_CYCLES,
+	PERF_HPP_REPORT__BLOCK_RANGE,
+	PERF_HPP_REPORT__BLOCK_DSO,
+	PERF_HPP_REPORT__BLOCK_BRANCH_COUNTER,
+	PERF_HPP_REPORT__BLOCK_MAX_INDEX
+};
+
+struct block_report {
+	struct block_hist	hist;
+	u64			cycles;
+	struct block_fmt	fmts[PERF_HPP_REPORT__BLOCK_MAX_INDEX];
+	int			nr_fmts;
+};
+
+void block_info__delete(struct block_info *bi);
+
+int64_t __block_info__cmp(struct hist_entry *left, struct hist_entry *right);
+
+int64_t block_info__cmp(struct perf_hpp_fmt *fmt __maybe_unused,
+			struct hist_entry *left, struct hist_entry *right);
+
+int block_info__process_sym(struct hist_entry *he, struct block_hist *bh,
+			    u64 *block_cycles_aggr, u64 total_cycles,
+			    unsigned int br_cntr_nr);
+
+struct block_report *block_info__create_report(struct evlist *evlist,
+					       u64 total_cycles,
+					       int *block_hpps, int nr_hpps,
+					       int *nr_reps);
+
+void block_info__free_report(struct block_report *reps, int nr_reps);
+
+int report__browse_block_hists(struct block_hist *bh, float min_percent,
+			       struct evsel *evsel, struct perf_env *env);
+
+float block_info__total_cycles_percent(struct hist_entry *he);
+
+#endif /* __PERF_BLOCK_H */