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, 118 insertions, 0 deletions

diff --git a/tools/perf/builtin-data.c b/tools/perf/builtin-data.c
new file mode 100644
index 000000000..1dd73ed6b
--- /dev/null
+++ b/tools/perf/builtin-data.c
@@ -0,0 +1,118 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/compiler.h>
+#include <stdio.h>
+#include <string.h>
+#include "builtin.h"
+#include "debug.h"
+#include <subcmd/parse-options.h>
+#include "data-convert.h"
+#include "util/util.h"
+
+typedef int (*data_cmd_fn_t)(int argc, const char **argv);
+
+struct data_cmd {
+	const char	*name;
+	const char	*summary;
+	data_cmd_fn_t	fn;
+};
+
+static struct data_cmd data_cmds[];
+
+#define for_each_cmd(cmd) \
+	for (cmd = data_cmds; cmd && cmd->name; cmd++)
+
+static const char * const data_subcommands[] = { "convert", NULL };
+
+static const char *data_usage[] = {
+	"perf data convert [<options>]",
+	NULL
+};
+
+static const char *to_json;
+static const char *to_ctf;
+static struct perf_data_convert_opts opts = {
+	.force = false,
+	.all = false,
+	.time_str = NULL,
+};
+
+static const struct option data_options[] = {
+		OPT_INCR('v', "verbose", &verbose, "be more verbose"),
+		OPT_STRING('i', "input", &input_name, "file", "input file name"),
+		OPT_STRING(0, "to-json", &to_json, NULL, "Convert to JSON format"),
+		OPT_STRING(0, "to-ctf", &to_ctf, NULL, "Convert to CTF format"),
+		OPT_BOOLEAN(0, "tod", &opts.tod, "Convert time to wall clock time"),
+		OPT_BOOLEAN('f', "force", &opts.force, "don't complain, do it"),
+		OPT_BOOLEAN(0, "all", &opts.all, "Convert all events"),
+		OPT_STRING(0, "time", &opts.time_str, "str",
+			   "Time span of interest (start,stop)"),
+		OPT_END()
+	};
+
+static int cmd_data_convert(int argc, const char **argv)
+{
+
+	argc = parse_options(argc, argv, data_options,
+			     data_usage, 0);
+	if (argc) {
+		usage_with_options(data_usage, data_options);
+		return -1;
+	}
+
+	if (to_json && to_ctf) {
+		pr_err("You cannot specify both --to-ctf and --to-json.\n");
+		return -1;
+	}
+	if (!to_json && !to_ctf) {
+		pr_err("You must specify one of --to-ctf or --to-json.\n");
+		return -1;
+	}
+
+	if (to_json)
+		return bt_convert__perf2json(input_name, to_json, &opts);
+
+	if (to_ctf) {
+#if defined(HAVE_BABELTRACE2_CTF_WRITER_SUPPORT) && defined(HAVE_LIBTRACEEVENT)
+		return bt_convert__perf2ctf(input_name, to_ctf, &opts);
+#else
+		pr_err("The babeltrace2 ctf support is not compiled in. Ensure you have both\n"
+			"libbabeltrace2-dev[el] and libtraceevent-dev[el] installed or set\n"
+			"PKG_CONFIG_PATH to find a local installation of those libraries.\n");
+		return -1;
+#endif
+	}
+
+	return 0;
+}
+
+static struct data_cmd data_cmds[] = {
+	{ "convert", "converts data file between formats", cmd_data_convert },
+	{ .name = NULL, },
+};
+
+int cmd_data(int argc, const char **argv)
+{
+	struct data_cmd *cmd;
+	const char *cmdstr;
+
+	argc = parse_options_subcommand(argc, argv, data_options, data_subcommands, data_usage,
+			     PARSE_OPT_STOP_AT_NON_OPTION);
+
+	if (!argc) {
+		usage_with_options(data_usage, data_options);
+		return -1;
+	}
+
+	cmdstr = argv[0];
+
+	for_each_cmd(cmd) {
+		if (strcmp(cmd->name, cmdstr))
+			continue;
+
+		return cmd->fn(argc, argv);
+	}
+
+	pr_err("Unknown command: %s\n", cmdstr);
+	usage_with_options(data_usage, data_options);
+	return -1;
+}