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 04DA921ABDB; Tue, 29 Apr 2025 17:19:42 +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=1745947182; cv=none; b=eeOD61MVV9f1SzH4z+cwWZ7+nDgZ1+kFg146jClDWJdGMmTw9HFHB41rkYnM7Ld97pzKpwl6cqKQ/PeqcGpl9HMy7S+5Omm/wcXFTCIJk1hgLyx4I2WzEkE8/aEZ68OD7EMINxx2MxQWeuO8pB1ui/cmYmVwDmQuOdoZjSPLaYE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745947182; c=relaxed/simple; bh=mPNT4DKM+f5efkyrolEWiDARQ9ZRwh3oLkejb29+VBw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=USVaK+foIWQitndTZJYSyxmIKgmyEz8NgxoT53hREUVqHwHtGjEWgBKN5OV+u5aNJb1gnjC5EzcDNp0c175SydayWtsam7LpSyvWzZuZX5R46JGedHDMrMcCKgMmb35NupH41wQJKXsXzT694bfCywJln03U5A1XAtV/xDgvT30= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=D0IjMb9m; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="D0IjMb9m" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8356BC4CEE3; Tue, 29 Apr 2025 17:19:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1745947181; bh=mPNT4DKM+f5efkyrolEWiDARQ9ZRwh3oLkejb29+VBw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=D0IjMb9mDNYTfxxYFwOU1EKpx4mUXNv6Qq0te9hQp9z8A8qtl71XIXvzKjwpGyrEy kcaxtxXWfUoOuvR0jzQGb78Noq91ew+FrVj6zvDHuAaijWxpZOxm+6FkziGoglTQVJ IYFeQP8mWbO5gS2BkK11hPvVJq8FxBA/Zt5tnVHU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Hou Tao , Alexei Starovoitov , Cliff Liu , He Zhe Subject: [PATCH 5.10 169/286] bpf: Check rcu_read_lock_trace_held() before calling bpf map helpers Date: Tue, 29 Apr 2025 18:41:13 +0200 Message-ID: <20250429161114.836721622@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250429161107.848008295@linuxfoundation.org> References: <20250429161107.848008295@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Hou Tao commit 169410eba271afc9f0fb476d996795aa26770c6d upstream. 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 [Minor conflict resolved due to code context change.] Signed-off-by: Cliff Liu Signed-off-by: He Zhe Signed-off-by: Greg Kroah-Hartman --- kernel/bpf/helpers.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -3,6 +3,7 @@ */ #include #include +#include #include #include #include @@ -24,12 +25,12 @@ * * 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()); + WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held()); return (unsigned long) map->ops->map_lookup_elem(map, key); } @@ -45,7 +46,7 @@ const struct bpf_func_proto bpf_map_look BPF_CALL_4(bpf_map_update_elem, struct bpf_map *, map, void *, key, void *, value, u64, flags) { - WARN_ON_ONCE(!rcu_read_lock_held()); + WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held()); return map->ops->map_update_elem(map, key, value, flags); } @@ -62,7 +63,7 @@ const struct bpf_func_proto bpf_map_upda BPF_CALL_2(bpf_map_delete_elem, struct bpf_map *, map, void *, key) { - WARN_ON_ONCE(!rcu_read_lock_held()); + WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held()); return map->ops->map_delete_elem(map, key); }