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/symsrc.h | 47 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 47 insertions(+) create mode 100644 tools/perf/util/symsrc.h (limited to 'tools/perf/util/symsrc.h') diff --git a/tools/perf/util/symsrc.h b/tools/perf/util/symsrc.h new file mode 100644 index 000000000..edf82028c --- /dev/null +++ b/tools/perf/util/symsrc.h @@ -0,0 +1,47 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __PERF_SYMSRC_ +#define __PERF_SYMSRC_ 1 + +#include +#include +#include "dso.h" + +#ifdef HAVE_LIBELF_SUPPORT +#include +#include +#endif +#include + +struct symsrc { + char *name; + int fd; + enum dso_binary_type type; + +#ifdef HAVE_LIBELF_SUPPORT + Elf *elf; + GElf_Ehdr ehdr; + + Elf_Scn *opdsec; + size_t opdidx; + GElf_Shdr opdshdr; + + Elf_Scn *symtab; + size_t symtab_idx; + GElf_Shdr symshdr; + + Elf_Scn *dynsym; + size_t dynsym_idx; + GElf_Shdr dynshdr; + + bool adjust_symbols; + bool is_64_bit; +#endif +}; + +int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name, enum dso_binary_type type); +void symsrc__destroy(struct symsrc *ss); + +bool symsrc__has_symtab(struct symsrc *ss); +bool symsrc__possibly_runtime(struct symsrc *ss); + +#endif /* __PERF_SYMSRC_ */ -- cgit v1.3.1