From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7F43D20F9D for ; Fri, 21 Jul 2023 19:25:26 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id F27EFC433C9; Fri, 21 Jul 2023 19:25:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1689967526; bh=W+SxhyQ/lc4vWwTT8Ky+kalmGv8L7EwNzoykiwTCfbw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JZkQsgfdZLXB4nWrPxcsF7b4GRRvWrJmW19zay3WRWpAnOYfd7Zii40cDcC9CCLtm X97tpG4Aq4JuEjoosOEnQ+MumheQEMnA/jZUYXF1K1wihIWfmYBNaHqHFSXqzPvMni Z+OxbQ7TDGbifbUh3PNNmBZz9GF2Ql3tPV+TIbYw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Steven Rostedt (Google)" , Jiri Olsa , "Masami Hiramatsu (Google)" Subject: [PATCH 6.1 193/223] fprobe: Release rethook after the ftrace_ops is unregistered Date: Fri, 21 Jul 2023 18:07:26 +0200 Message-ID: <20230721160529.113510867@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230721160520.865493356@linuxfoundation.org> References: <20230721160520.865493356@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Jiri Olsa commit 5f81018753dfd4989e33ece1f0cb6b8aae498b82 upstream. While running bpf selftests it's possible to get following fault: general protection fault, probably for non-canonical address \ 0x6b6b6b6b6b6b6b6b: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC NOPTI ... Call Trace: fprobe_handler+0xc1/0x270 ? __pfx_bpf_testmod_init+0x10/0x10 ? __pfx_bpf_testmod_init+0x10/0x10 ? bpf_fentry_test1+0x5/0x10 ? bpf_fentry_test1+0x5/0x10 ? bpf_testmod_init+0x22/0x80 ? do_one_initcall+0x63/0x2e0 ? rcu_is_watching+0xd/0x40 ? kmalloc_trace+0xaf/0xc0 ? do_init_module+0x60/0x250 ? __do_sys_finit_module+0xac/0x120 ? do_syscall_64+0x37/0x90 ? entry_SYSCALL_64_after_hwframe+0x72/0xdc In unregister_fprobe function we can't release fp->rethook while it's possible there are some of its users still running on another cpu. Moving rethook_free call after fp->ops is unregistered with unregister_ftrace_function call. Link: https://lore.kernel.org/all/20230615115236.3476617-1-jolsa@kernel.org/ Fixes: 5b0ab78998e3 ("fprobe: Add exit_handler support") Cc: stable@vger.kernel.org Reviewed-by: Steven Rostedt (Google) Signed-off-by: Jiri Olsa Acked-by: Masami Hiramatsu (Google) Signed-off-by: Masami Hiramatsu (Google) Signed-off-by: Greg Kroah-Hartman --- kernel/trace/fprobe.c | 12 +++--------- 1 file changed, 3 insertions(+), 9 deletions(-) --- a/kernel/trace/fprobe.c +++ b/kernel/trace/fprobe.c @@ -307,19 +307,13 @@ int unregister_fprobe(struct fprobe *fp) fp->ops.saved_func != fprobe_kprobe_handler)) return -EINVAL; - /* - * rethook_free() starts disabling the rethook, but the rethook handlers - * may be running on other processors at this point. To make sure that all - * current running handlers are finished, call unregister_ftrace_function() - * after this. - */ - if (fp->rethook) - rethook_free(fp->rethook); - ret = unregister_ftrace_function(&fp->ops); if (ret < 0) return ret; + if (fp->rethook) + rethook_free(fp->rethook); + ftrace_free_filter(&fp->ops); return ret;