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 750ED1420B2; Tue, 16 Jan 2024 19:55:58 +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=1705434958; cv=none; b=EwHBrlVXc2TmHndLpAH1ygmmSxe9TcW9IhWcWljfaKERBIxtnJoeiWegIgpIIgYLHvKyvrZJqokcwKcJZ7UekFgjZPc377HNs1uZita4Tz2Aa6DiyAII7dPW0n7t8Oa2JjxzgO3pQbONb8NUrErBb8unypDARI0R75rcKKkO7kg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705434958; c=relaxed/simple; bh=3IAgGDz0yjGZhxDZbsMLsE9h3ifZOAZyMRq8lFAyhIA=; 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=mYBnTfe84+mBWtsqBUvl8r8cwAEuSNurJBIrr1wIjOfXpRa/vR5HjW1HfECduWhucd3Zoe1JwulmozKO7csMLsf+XdQFP2u9MorMgtNc7dX2GFwRRdPgB9kLI3GWX1O5jHAcA8FqV7x8I/w/iRff7PNsaN6EzbogrS9KMbFI+lM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=V5Fkq5nQ; 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="V5Fkq5nQ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5C25FC43390; Tue, 16 Jan 2024 19:55:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1705434958; bh=3IAgGDz0yjGZhxDZbsMLsE9h3ifZOAZyMRq8lFAyhIA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=V5Fkq5nQmPK+HdgaFEGnaoal5Ar/jxxIimsRt6VLTPSczz/38O77MDaZHjWmKBaz0 mML0EOJQ9LcS2BnqhT7GHbIXBlxit1TdHCb27I81NHsNy0LG7zdOkfYQmwkNlvoJ8J pyOYdE0Qbsk6hGdTzqCXcKUc4tjR9wl6mrJnhs2cAdJbfMlzZAZMeHO4RTtzCsoLQS v4JnHhl9R2wNxt+uwLODiVgwSfiXVd67ErwJA6MyYa19ryMgd1/sUhuLQk47t0E++2 vxM3wdvV47QeD5AqcT0ezHEiBfJ23prio7bpBcJp0sSWAz7+aoi8aYYKgRekZ5iWyH tY3mqYEzOLtUg== 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 6.1 21/68] bpf: Check rcu_read_lock_trace_held() before calling bpf map helpers Date: Tue, 16 Jan 2024 14:53:20 -0500 Message-ID: <20240116195511.255854-21-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240116195511.255854-1-sashal@kernel.org> References: <20240116195511.255854-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.1.73 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 6212e4ae084b..34135fbd6097 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -28,12 +28,13 @@ * * 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); } @@ -49,7 +50,8 @@ 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); } @@ -66,7 +68,8 @@ 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