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, 69 insertions, 0 deletions

diff --git a/tools/perf/util/srcline.h b/tools/perf/util/srcline.h
new file mode 100644
index 000000000..1018cbc88
--- /dev/null
+++ b/tools/perf/util/srcline.h
@@ -0,0 +1,69 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef PERF_SRCLINE_H
+#define PERF_SRCLINE_H
+
+#include <linux/list.h>
+#include <linux/rbtree.h>
+#include <linux/types.h>
+
+struct dso;
+struct symbol;
+
+extern bool srcline_full_filename;
+char *get_srcline(struct dso *dso, u64 addr, struct symbol *sym,
+		  bool show_sym, bool show_addr, u64 ip);
+char *__get_srcline(struct dso *dso, u64 addr, struct symbol *sym,
+		  bool show_sym, bool show_addr, bool unwind_inlines,
+		  u64 ip);
+void zfree_srcline(char **srcline);
+char *get_srcline_split(struct dso *dso, u64 addr, unsigned *line);
+
+/* insert the srcline into the DSO, which will take ownership */
+void srcline__tree_insert(struct rb_root_cached *tree, u64 addr, char *srcline);
+/* find previously inserted srcline */
+char *srcline__tree_find(struct rb_root_cached *tree, u64 addr);
+/* delete all srclines within the tree */
+void srcline__tree_delete(struct rb_root_cached *tree);
+
+extern char *srcline__unknown;
+#define SRCLINE_UNKNOWN srcline__unknown
+
+#define MAX_INLINE_NEST 1024
+
+struct inline_list {
+	struct symbol		*symbol;
+	char			*srcline;
+	struct list_head	list;
+};
+
+struct inline_node {
+	u64			addr;
+	struct list_head	val;
+	struct rb_node		rb_node;
+};
+
+/* parse inlined frames for the given address */
+struct inline_node *dso__parse_addr_inlines(struct dso *dso, u64 addr,
+					    struct symbol *sym);
+/* free resources associated to the inline node list */
+void inline_node__delete(struct inline_node *node);
+void inline_node__clear_frames(struct inline_node *node);
+
+/* insert the inline node list into the DSO, which will take ownership */
+void inlines__tree_insert(struct rb_root_cached *tree,
+			  struct inline_node *inlines);
+/* find previously inserted inline node list */
+struct inline_node *inlines__tree_find(struct rb_root_cached *tree, u64 addr);
+/* delete all nodes within the tree of inline_node s */
+void inlines__tree_delete(struct rb_root_cached *tree);
+
+int inline_list__append(struct symbol *symbol, char *srcline, struct inline_node *node);
+int inline_list__append_tail(struct symbol *symbol, char *srcline, struct inline_node *node);
+char *srcline_from_fileline(const char *file, unsigned int line);
+struct symbol *new_inline_sym(struct dso *dso,
+			      struct symbol *base_sym,
+			      const char *funcname);
+
+int addr2line_configure(const char *var, const char *value, void *cb);
+
+#endif /* PERF_SRCLINE_H */