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 66C601E7C01; Fri, 4 Apr 2025 00:05:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743725118; cv=none; b=tOPCfuKpX2KOJu7cCinGVhWbdP/F5k0+flSAHy6qucfqeWT80z1CPYzXFmOceVOj5lQ/kIXP+8sazYIpylbKtjcugdg0c8D4T8xvtEXEf69DrgZrmrtIA0HkE/XzCSjpmcw8p5dCOm/oaNUNCWMz1E+tRt0GjFlSwva9nH0Jnqo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743725118; c=relaxed/simple; bh=PFnM5LjoAR7cGmB0S9l3LZS4WvW7TOkVuyAIaMeuV10=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=I+ylAfvMMZXhc5q2kqtbpBu1vdmhweEJha3bGrdTZ1T8yx0QPmnhY1tPiSawBBmYMhfIlxV/drsQAlBApS5tj90+FiW1NexFDYV7+0FwX7g3K8AuwlPhVF691qvvc4tPcgvh8nrlsBW5SSvdqV/7Z4iPQxYOfbie1mhlNeU4TRs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=IQ8hMeBt; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="IQ8hMeBt" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E3040C4CEE3; Fri, 4 Apr 2025 00:05:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1743725118; bh=PFnM5LjoAR7cGmB0S9l3LZS4WvW7TOkVuyAIaMeuV10=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IQ8hMeBt9LZ0DG4UqoR/53zeeAUsOP6rzu2czab3PrCLTBWg9lArI6o5eiKEEo72t vbXQWwmuSlEwDavKwnf2BDZg2CpCJIIE94JoeXkTarcEQi6KBmdD2wGUBEV3xs90f4 hIRdneLAhTon8lK3yXhupHBPtAiLv1yR5b0gHu6I1zN9+4j/W3j5JBk4Cpr+TD7TsJ YJ+vorvcWi8pdSM6ZVKCbxwwkX/QI6fB3DIh65rwtigpP5sRf+VwAVcFTD+q1n5S7b inY8GpRWGkalKMi2jpRh7NHNyUGI1H7XoDpegka4fkJyD1lMm2E5QaZ+nbtQDVSmwZ kNJKai5f+fQFw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Alexei Starovoitov , Andrii Nakryiko , Sasha Levin , song@kernel.org, kpsingh@kernel.org, mattbobrowski@google.com, daniel@iogearbox.net, rostedt@goodmis.org, mhiramat@kernel.org, bpf@vger.kernel.org, linux-trace-kernel@vger.kernel.org Subject: [PATCH AUTOSEL 6.13 11/22] bpf: Fix deadlock between rcu_tasks_trace and event_mutex. Date: Thu, 3 Apr 2025 20:04:40 -0400 Message-Id: <20250404000453.2688371-11-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250404000453.2688371-1-sashal@kernel.org> References: <20250404000453.2688371-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.13.9 Content-Transfer-Encoding: 8bit From: Alexei Starovoitov [ Upstream commit 4580f4e0ebdf8dc8d506ae926b88510395a0c1d1 ] Fix the following deadlock: CPU A _free_event() perf_kprobe_destroy() mutex_lock(&event_mutex) perf_trace_event_unreg() synchronize_rcu_tasks_trace() There are several paths where _free_event() grabs event_mutex and calls sync_rcu_tasks_trace. Above is one such case. CPU B bpf_prog_test_run_syscall() rcu_read_lock_trace() bpf_prog_run_pin_on_cpu() bpf_prog_load() bpf_tracing_func_proto() trace_set_clr_event() mutex_lock(&event_mutex) Delegate trace_set_clr_event() to workqueue to avoid such lock dependency. Signed-off-by: Alexei Starovoitov Signed-off-by: Andrii Nakryiko Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20250224221637.4780-1-alexei.starovoitov@gmail.com Signed-off-by: Sasha Levin --- kernel/trace/bpf_trace.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 2c2205e91fee9..24479ef395d49 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -403,7 +403,7 @@ static const struct bpf_func_proto bpf_trace_printk_proto = { .arg2_type = ARG_CONST_SIZE, }; -static void __set_printk_clr_event(void) +static void __set_printk_clr_event(struct work_struct *work) { /* * This program might be calling bpf_trace_printk, @@ -416,10 +416,11 @@ static void __set_printk_clr_event(void) if (trace_set_clr_event("bpf_trace", "bpf_trace_printk", 1)) pr_warn_ratelimited("could not enable bpf_trace_printk events"); } +static DECLARE_WORK(set_printk_work, __set_printk_clr_event); const struct bpf_func_proto *bpf_get_trace_printk_proto(void) { - __set_printk_clr_event(); + schedule_work(&set_printk_work); return &bpf_trace_printk_proto; } @@ -462,7 +463,7 @@ static const struct bpf_func_proto bpf_trace_vprintk_proto = { const struct bpf_func_proto *bpf_get_trace_vprintk_proto(void) { - __set_printk_clr_event(); + schedule_work(&set_printk_work); return &bpf_trace_vprintk_proto; } -- 2.39.5