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 1D2DA1F8F09; Fri, 4 Apr 2025 00:06:04 +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=1743725166; cv=none; b=XbsJ2s6KjfKXFISdi0HWIAomADC6sRowwewny58Ug5O5WrX793a4katN9yk928uw04pVFq+evgqD4gaEzh2Xn2JY3k3/RGyMz078Ra/FlAnIfjlJCHSPng/RGb9DP8q1Ermwa2bXVQ9f6xLL/4Bae7dkjfKdmkJCOA4ePhObuWs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743725166; c=relaxed/simple; bh=KeQabmXxC4Y82ajO6kP1JKaGMpfZvEtcGVDdcAuuq3E=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=kGR+rvbjfzSj+Ih/TRSHzbtlacT3ZB4oYne64Cfq+tigZOujAnvssbjV7vyMGugErFZ93DtvNaQ9h785ZEGafLseU32LExo6N/nOITAcXRbZwYSDB6DMKj9pAOKLF0stwku7pk755+YDe6m8YZrXl3vmBHhZePc9KgK7hElfZGY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=KCQZIgNs; 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="KCQZIgNs" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3B364C4CEE5; Fri, 4 Apr 2025 00:06:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1743725164; bh=KeQabmXxC4Y82ajO6kP1JKaGMpfZvEtcGVDdcAuuq3E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KCQZIgNsTe9acZUmnMwkJKxpX11TbLd4SpSSisplsQQAbGQjP1TNwgh+VSb1Ypstk fKq6Nz3/SDB1UH36Q6SFgjftSFcfjHwNzL346+NBEYO3Oh3cmpz3tdZbRj+f31WTQl tQFORxANC+qp0VSJM5PEGQIMCCFD/uTBNqNqJ6U7alzsHGYH2+9GoLhDGJdjgYnuSj ed2EOWHZ7yX2EixZk6cBxLutMCQcFjyQRHJ0BPa+IvxKGrJ8H9NFMm5TRAH/FFOQld 3+Zfoo+62GmFgfMON5g1AxLtx9BOtZmmXzAoZpXsG3l+6IbnJ/lM/KRGdqBmBhZGxC kzB9bMeeBGA+Q== 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 6.12 10/20] bpf: Fix deadlock between rcu_tasks_trace and event_mutex. Date: Thu, 3 Apr 2025 20:05:30 -0400 Message-Id: <20250404000541.2688670-10-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250404000541.2688670-1-sashal@kernel.org> References: <20250404000541.2688670-1-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 6.12.21 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 449efaaa387a6..cf45759fd4fc0 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