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 9CFBD28E01; Tue, 16 Jan 2024 19:43:59 +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=1705434239; cv=none; b=hIYukrb/rsNKoNNsy8UVpVdOp84p49Jp60YBcnaLm9AaPCUusmnZMKyo/akCDTIuOZ+6Bj/DQ/FigfysnNR6+5NIIbNoQZxxC8Aa8phbmxbv+Puvz80xRZikKf5i4M+C/VVx9GW0RYfkNQZDrM5clqejZcRgTihBnHm1SyAXOvs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705434239; c=relaxed/simple; bh=vuBI9Flk2osas8XVrL3HId0po9MjKVz8FBootcs+Va4=; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID: X-Mailer:In-Reply-To:References:MIME-Version:X-stable: X-Patchwork-Hint:X-stable-base:Content-Transfer-Encoding; b=RNVZNRoNVtVBvbaTYb1fc8qqA4uqaxljTnctclvw8ebLhlSjE5AinIOpxw4yfvuYGnushVzOHk995f7/73AyXahbS0mnRta4EB9qrJhVtoeBRnNe3k3p3231ovgMfPvGl1GFVVEiQuYqVrqx6ojrZC2yWvf8IrHfHiPFtHZbJJs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=F+CcMzY6; 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="F+CcMzY6" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 70252C433C7; Tue, 16 Jan 2024 19:43:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1705434239; bh=vuBI9Flk2osas8XVrL3HId0po9MjKVz8FBootcs+Va4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=F+CcMzY6/3kDTUsJS8JNWT8ptmVz9yNC+TT/E7X0Xa6GbY/mssnkls2/i3gj7ryYJ tpmMBkB1RdoLwlhr49dbPKy6mmyWU19P7DJ0vjlvbq2WIzxCnHbxWFfVNSSl5k64kw C/9dQrjfP4INZGLzD1V3mvK/auzoLvZxgRSTfos4gLJgOIJt6IdFT0VaEvCra0N7Hq WFEi4pMjUVLqb+qI4Qbv7h6/0nTVoU57W1KmoR2foYaUYKDbASFYd99sc51NrTGK4S euQ1XnqkoXx/aJSCb69Rs72nTKPEb6jBBXG4dHmEFtsaK7CltMfJouISl+GomoyKNv Qjuj9pfOLNWRw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Hou Tao , Alexei Starovoitov , Sasha Levin , daniel@iogearbox.net, andrii@kernel.org, bpf@vger.kernel.org Subject: [PATCH AUTOSEL 6.7 037/108] bpf: Check rcu_read_lock_trace_held() before calling bpf map helpers Date: Tue, 16 Jan 2024 14:39:03 -0500 Message-ID: <20240116194225.250921-37-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240116194225.250921-1-sashal@kernel.org> References: <20240116194225.250921-1-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 6.7 Content-Transfer-Encoding: 8bit From: Hou Tao [ Upstream commit 169410eba271afc9f0fb476d996795aa26770c6d ] These three bpf_map_{lookup,update,delete}_elem() helpers are also available for sleepable bpf program, so add the corresponding lock assertion for sleepable bpf program, otherwise the following warning will be reported when a sleepable bpf program manipulates bpf map under interpreter mode (aka bpf_jit_enable=0): WARNING: CPU: 3 PID: 4985 at kernel/bpf/helpers.c:40 ...... CPU: 3 PID: 4985 Comm: test_progs Not tainted 6.6.0+ #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) ...... RIP: 0010:bpf_map_lookup_elem+0x54/0x60 ...... Call Trace: ? __warn+0xa5/0x240 ? bpf_map_lookup_elem+0x54/0x60 ? report_bug+0x1ba/0x1f0 ? handle_bug+0x40/0x80 ? exc_invalid_op+0x18/0x50 ? asm_exc_invalid_op+0x1b/0x20 ? __pfx_bpf_map_lookup_elem+0x10/0x10 ? rcu_lockdep_current_cpu_online+0x65/0xb0 ? rcu_is_watching+0x23/0x50 ? bpf_map_lookup_elem+0x54/0x60 ? __pfx_bpf_map_lookup_elem+0x10/0x10 ___bpf_prog_run+0x513/0x3b70 __bpf_prog_run32+0x9d/0xd0 ? __bpf_prog_enter_sleepable_recur+0xad/0x120 ? __bpf_prog_enter_sleepable_recur+0x3e/0x120 bpf_trampoline_6442580665+0x4d/0x1000 __x64_sys_getpgid+0x5/0x30 ? do_syscall_64+0x36/0xb0 entry_SYSCALL_64_after_hwframe+0x6e/0x76 Signed-off-by: Hou Tao Link: https://lore.kernel.org/r/20231204140425.1480317-2-houtao@huaweicloud.com Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin --- kernel/bpf/helpers.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index 56b0c1f678ee..f43038931935 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -32,12 +32,13 @@ * * Different map implementations will rely on rcu in map methods * lookup/update/delete, therefore eBPF programs must run under rcu lock - * if program is allowed to access maps, so check rcu_read_lock_held in - * all three functions. + * if program is allowed to access maps, so check rcu_read_lock_held() or + * rcu_read_lock_trace_held() in all three functions. */ BPF_CALL_2(bpf_map_lookup_elem, struct bpf_map *, map, void *, key) { - WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_bh_held()); + WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held() && + !rcu_read_lock_bh_held()); return (unsigned long) map->ops->map_lookup_elem(map, key); } @@ -53,7 +54,8 @@ const struct bpf_func_proto bpf_map_lookup_elem_proto = { BPF_CALL_4(bpf_map_update_elem, struct bpf_map *, map, void *, key, void *, value, u64, flags) { - WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_bh_held()); + WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held() && + !rcu_read_lock_bh_held()); return map->ops->map_update_elem(map, key, value, flags); } @@ -70,7 +72,8 @@ const struct bpf_func_proto bpf_map_update_elem_proto = { BPF_CALL_2(bpf_map_delete_elem, struct bpf_map *, map, void *, key) { - WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_bh_held()); + WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held() && + !rcu_read_lock_bh_held()); return map->ops->map_delete_elem(map, key); } -- 2.43.0