From patchwork Mon Aug 19 16:28:05 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matteo Croce X-Patchwork-Id: 13768602 Received: from mail-wr1-f51.google.com (mail-wr1-f51.google.com [209.85.221.51]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7049682D94; Mon, 19 Aug 2024 16:28:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.51 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724084924; cv=none; b=fDa7vhOUOxN0yPP5g+jNrBmdKV/gn/6XV2AbYpU+CTpcFRy19id1uKbaSmdEVyJ0crsk77yGr4JTNWDlyXWWM7/4s8rokCyAtQrdQYSrc4oBTaNRj01ZXCg+rQyPX9Go9L4YesdPI/zgV1c7i0FMWCj1d9QJXx74EzCgPX4itUc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724084924; c=relaxed/simple; bh=z8kWQOk0+SgPOW2ErE0TdIUZyPc6eFdb5/uFyMNQevU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Fmo0LJG6FaXee7AZAeL+qYExQb2zAuB74Sn5zMe5YCpZrwpw/H3tvbpEC1WVMUp7I1A/rwJWEisgEBdMXlxva+NxvUblXn60Y6VKRODeMMuVahWKdZlF27AWTNXSbZBxKZCPSE7HLBvw9c9i/X7Tw0eeIgnNP4fo/Du5NGxDQMw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=VyIf9SyF; arc=none smtp.client-ip=209.85.221.51 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="VyIf9SyF" Received: by mail-wr1-f51.google.com with SMTP id ffacd0b85a97d-37196786139so2223688f8f.2; Mon, 19 Aug 2024 09:28:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1724084921; x=1724689721; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=JgrYssnQV/ZXUz1RX8badJMMrwHcEJA9d3TIal8ZnX0=; b=VyIf9SyFUEufwI5et9nRJgkUAoYmuRjQokmWc79FumllrbvabaePahqNcXvPjUSykV 1V1jP41yN/mmPcMRbaf1QnPfe2UYZ9ikXdQ3TkiCb4/VFXSGKyCUeVpq7f+V8LLyQ7BH lnSIwOozzIEKGpVih1TSDlyKo44NZyjTFdonCRHBD0Nk5NXrimCon1wZlOl659frxCBw GVSuDaR4IeZ0iNV9qnqhf9Qs3S6W3LvLu7F/FpBXnerK7KiQMmhpT3emjg0iJ5GV761P jbjl0+f5QQGoC3fm6agYRUKzgIistyk7+OtrjhX7wQnhlkfK1CnGnv1nvscZ21cfrzAq oZ3g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1724084921; x=1724689721; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=JgrYssnQV/ZXUz1RX8badJMMrwHcEJA9d3TIal8ZnX0=; b=LmOTPZxfqcTmX/uNX5BeA8V+omXM19PqICg7nUBRnjAOXmVjblw6FCHsA4+EyH/93A v+xGlbaPANAE/PlzBhmsRYELx1E++7RJkshqkII78eTjWHaXpmzxYLi2eAbUSdVxRQdM /U5aNy0/m12FkzBpMEkK97yNz7kEseEndvTVSF10cEQZZujj2AlX0Om5omZZ5tKrl/FP uAQcZ0sqRUnyq5FTWL2Fg9Y/KaRevI5+xbqm7sbCJJ4DSTl+APdnDEB1/m2W92IwBMTW Xe2TgMrXbggN/huM8QlHWCnKPyWGUpFUgzAB/RawHY4UgXxGD+9TtWwne1lUuzMBPIyF F4lA== X-Forwarded-Encrypted: i=1; AJvYcCWDxX6x3tCp9yHjpb9toG+Gp3D6mkv3w++qBpFPz9EmBE6f8Z+fRHPPGZRx8FSpFmDuewlWiJFXzeQ0q6wA0BcSqn1dS/qmvqOZRs11LYq596eeTVUIC6C6PA2O9iB/vKUUcNVXp0/o X-Gm-Message-State: AOJu0YzVL/xWB7f4Kt5CTWERBniyyUXiJPYxC/llvSYs6tO4c7zRw7gN g+YcbEfGXBF0tr0EI1AF6liPSSPTyhO3/vLDyj3079obONGSpGkAd7WAIw== X-Google-Smtp-Source: AGHT+IEQGvoMGjBlsuR2gbvEH4RP0OUeH5hv1/ipdWdp7vSpXGjjw8baUTrpXJemmHHm2d+jxPd3jQ== X-Received: by 2002:a5d:5a15:0:b0:366:f041:935d with SMTP id ffacd0b85a97d-371946bcb41mr10828246f8f.60.1724084920453; Mon, 19 Aug 2024 09:28:40 -0700 (PDT) Received: from lenovo.fritz.box ([151.72.61.55]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-37189897029sm10922134f8f.74.2024.08.19.09.28.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 19 Aug 2024 09:28:40 -0700 (PDT) From: Matteo Croce To: Andrii Nakryiko , Alexei Starovoitov , Daniel Borkmann , Steven Rostedt , Masami Hiramatsu , bpf@vger.kernel.org, linux-trace-kernel@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Matteo Croce Subject: [PATCH bpf-next v6 2/2] bpf: allow bpf_current_task_under_cgroup() with BPF_CGROUP_* Date: Mon, 19 Aug 2024 18:28:05 +0200 Message-ID: <20240819162805.78235-3-technoboy85@gmail.com> X-Mailer: git-send-email 2.46.0 In-Reply-To: <20240819162805.78235-1-technoboy85@gmail.com> References: <20240819162805.78235-1-technoboy85@gmail.com> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Matteo Croce The helper bpf_current_task_under_cgroup() currently is only allowed for tracing programs, allow its usage also in the BPF_CGROUP_* program types. Move the code from kernel/trace/bpf_trace.c to kernel/bpf/helpers.c, so it compiles also without CONFIG_BPF_EVENTS. This will be used in systemd-networkd to monitor the sysctl writes, and filter it's own writes from others: https://github.com/systemd/systemd/pull/32212 Signed-off-by: Matteo Croce --- include/linux/bpf.h | 1 + kernel/bpf/cgroup.c | 2 ++ kernel/bpf/helpers.c | 23 +++++++++++++++++++++++ kernel/trace/bpf_trace.c | 27 ++------------------------- 4 files changed, 28 insertions(+), 25 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index b9425e410bcb..f0192c173ed8 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -3206,6 +3206,7 @@ extern const struct bpf_func_proto bpf_sock_hash_update_proto; extern const struct bpf_func_proto bpf_get_current_cgroup_id_proto; extern const struct bpf_func_proto bpf_get_current_ancestor_cgroup_id_proto; extern const struct bpf_func_proto bpf_get_cgroup_classid_curr_proto; +extern const struct bpf_func_proto bpf_current_task_under_cgroup_proto; extern const struct bpf_func_proto bpf_msg_redirect_hash_proto; extern const struct bpf_func_proto bpf_msg_redirect_map_proto; extern const struct bpf_func_proto bpf_sk_redirect_hash_proto; diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c index 8ba73042a239..e7113d700b87 100644 --- a/kernel/bpf/cgroup.c +++ b/kernel/bpf/cgroup.c @@ -2581,6 +2581,8 @@ cgroup_current_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) case BPF_FUNC_get_cgroup_classid: return &bpf_get_cgroup_classid_curr_proto; #endif + case BPF_FUNC_current_task_under_cgroup: + return &bpf_current_task_under_cgroup_proto; default: return NULL; } diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index 26b9649ab4ce..12e3aa40b180 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -2458,6 +2458,29 @@ __bpf_kfunc long bpf_task_under_cgroup(struct task_struct *task, return ret; } +BPF_CALL_2(bpf_current_task_under_cgroup, struct bpf_map *, map, u32, idx) +{ + struct bpf_array *array = container_of(map, struct bpf_array, map); + struct cgroup *cgrp; + + if (unlikely(idx >= array->map.max_entries)) + return -E2BIG; + + cgrp = READ_ONCE(array->ptrs[idx]); + if (unlikely(!cgrp)) + return -EAGAIN; + + return task_under_cgroup_hierarchy(current, cgrp); +} + +const struct bpf_func_proto bpf_current_task_under_cgroup_proto = { + .func = bpf_current_task_under_cgroup, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_CONST_MAP_PTR, + .arg2_type = ARG_ANYTHING, +}; + /** * bpf_task_get_cgroup1 - Acquires the associated cgroup of a task within a * specific cgroup1 hierarchy. The cgroup1 hierarchy is identified by its diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index d557bb11e0ff..b69a39316c0c 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -797,29 +797,6 @@ const struct bpf_func_proto bpf_task_pt_regs_proto = { .ret_btf_id = &bpf_task_pt_regs_ids[0], }; -BPF_CALL_2(bpf_current_task_under_cgroup, struct bpf_map *, map, u32, idx) -{ - struct bpf_array *array = container_of(map, struct bpf_array, map); - struct cgroup *cgrp; - - if (unlikely(idx >= array->map.max_entries)) - return -E2BIG; - - cgrp = READ_ONCE(array->ptrs[idx]); - if (unlikely(!cgrp)) - return -EAGAIN; - - return task_under_cgroup_hierarchy(current, cgrp); -} - -static const struct bpf_func_proto bpf_current_task_under_cgroup_proto = { - .func = bpf_current_task_under_cgroup, - .gpl_only = false, - .ret_type = RET_INTEGER, - .arg1_type = ARG_CONST_MAP_PTR, - .arg2_type = ARG_ANYTHING, -}; - struct send_signal_irq_work { struct irq_work irq_work; struct task_struct *task; @@ -1480,8 +1457,6 @@ bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_get_numa_node_id_proto; case BPF_FUNC_perf_event_read: return &bpf_perf_event_read_proto; - case BPF_FUNC_current_task_under_cgroup: - return &bpf_current_task_under_cgroup_proto; case BPF_FUNC_get_prandom_u32: return &bpf_get_prandom_u32_proto; case BPF_FUNC_probe_write_user: @@ -1510,6 +1485,8 @@ bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_cgrp_storage_get_proto; case BPF_FUNC_cgrp_storage_delete: return &bpf_cgrp_storage_delete_proto; + case BPF_FUNC_current_task_under_cgroup: + return &bpf_current_task_under_cgroup_proto; #endif case BPF_FUNC_send_signal: return &bpf_send_signal_proto;