From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops 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 --- tools/perf/util/dsos.h | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 52 insertions(+) create mode 100644 tools/perf/util/dsos.h (limited to 'tools/perf/util/dsos.h') diff --git a/tools/perf/util/dsos.h b/tools/perf/util/dsos.h new file mode 100644 index 000000000..a26774950 --- /dev/null +++ b/tools/perf/util/dsos.h @@ -0,0 +1,52 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __PERF_DSOS +#define __PERF_DSOS + +#include +#include +#include +#include +#include "rwsem.h" + +struct dso; +struct dso_id; +struct kmod_path; +struct machine; + +/* + * Collection of DSOs as an array for iteration speed, but sorted for O(n) + * lookup. + */ +struct dsos { + struct rw_semaphore lock; + struct dso **dsos; + unsigned int cnt; + unsigned int allocated; + bool sorted; +}; + +void dsos__init(struct dsos *dsos); +void dsos__exit(struct dsos *dsos); + +int __dsos__add(struct dsos *dsos, struct dso *dso); +int dsos__add(struct dsos *dsos, struct dso *dso); +struct dso *dsos__find(struct dsos *dsos, const char *name, bool cmp_short); + +struct dso *dsos__findnew_id(struct dsos *dsos, const char *name, const struct dso_id *id); + +bool dsos__read_build_ids(struct dsos *dsos, bool with_hits); + +size_t dsos__fprintf_buildid(struct dsos *dsos, FILE *fp, + bool (skip)(struct dso *dso, int parm), int parm); +size_t dsos__fprintf(struct dsos *dsos, FILE *fp); + +int dsos__hit_all(struct dsos *dsos); + +struct dso *dsos__findnew_module_dso(struct dsos *dsos, struct machine *machine, + struct kmod_path *m, const char *filename); + +struct dso *dsos__find_kernel_dso(struct dsos *dsos); + +int dsos__for_each_dso(struct dsos *dsos, int (*cb)(struct dso *dso, void *data), void *data); + +#endif /* __PERF_DSOS */ -- cgit v1.3.1