From patchwork Mon Jul 26 16:12:00 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrii Nakryiko X-Patchwork-Id: 12400019 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-17.0 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5F6CBC43216 for ; Mon, 26 Jul 2021 16:12:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4D67C60C41 for ; Mon, 26 Jul 2021 16:12:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233278AbhGZPcP convert rfc822-to-8bit (ORCPT ); Mon, 26 Jul 2021 11:32:15 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:61544 "EHLO mx0b-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233101AbhGZPb6 (ORCPT ); Mon, 26 Jul 2021 11:31:58 -0400 Received: from pps.filterd (m0109332.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 16QGACKu028984 for ; Mon, 26 Jul 2021 09:12:26 -0700 Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com with ESMTP id 3a0gm0aeux-5 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Mon, 26 Jul 2021 09:12:26 -0700 Received: from intmgw001.05.ash7.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:82::f) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Mon, 26 Jul 2021 09:12:24 -0700 Received: by devbig012.ftw2.facebook.com (Postfix, from userid 137359) id 4D62F3D405AD; Mon, 26 Jul 2021 09:12:20 -0700 (PDT) From: Andrii Nakryiko To: , , CC: , , Peter Zijlstra Subject: [PATCH v2 bpf-next 03/14] bpf: refactor perf_event_set_bpf_prog() to use struct bpf_prog input Date: Mon, 26 Jul 2021 09:12:00 -0700 Message-ID: <20210726161211.925206-4-andrii@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210726161211.925206-1-andrii@kernel.org> References: <20210726161211.925206-1-andrii@kernel.org> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-ORIG-GUID: Eh-wm2j1k7hFJi7oHf2NC0Ly88BsFHu5 X-Proofpoint-GUID: Eh-wm2j1k7hFJi7oHf2NC0Ly88BsFHu5 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.391,18.0.790 definitions=2021-07-26_10:2021-07-26,2021-07-26 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 lowpriorityscore=0 phishscore=0 spamscore=0 priorityscore=1501 malwarescore=0 impostorscore=0 bulkscore=0 mlxlogscore=999 mlxscore=0 adultscore=0 suspectscore=0 clxscore=1015 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2104190000 definitions=main-2107260094 X-FB-Internal: deliver Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Make internal perf_event_set_bpf_prog() use struct bpf_prog pointer as an input argument, which makes it easier to re-use for other internal uses (coming up for BPF link in the next patch). BPF program FD is not as convenient and in some cases it's not available. So switch to struct bpf_prog, move out refcounting outside and let caller do bpf_prog_put() in case of an error. This follows the approach of most of the other BPF internal functions. Cc: Peter Zijlstra Signed-off-by: Andrii Nakryiko Acked-by: Peter Zijlstra (Intel) Acked-by: Yonghong Song --- kernel/events/core.c | 61 ++++++++++++++++++++------------------------ 1 file changed, 28 insertions(+), 33 deletions(-) diff --git a/kernel/events/core.c b/kernel/events/core.c index 464917096e73..bf4689403498 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -5574,7 +5574,7 @@ static inline int perf_fget_light(int fd, struct fd *p) static int perf_event_set_output(struct perf_event *event, struct perf_event *output_event); static int perf_event_set_filter(struct perf_event *event, void __user *arg); -static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd); +static int perf_event_set_bpf_prog(struct perf_event *event, struct bpf_prog *prog); static int perf_copy_attr(struct perf_event_attr __user *uattr, struct perf_event_attr *attr); @@ -5637,7 +5637,22 @@ static long _perf_ioctl(struct perf_event *event, unsigned int cmd, unsigned lon return perf_event_set_filter(event, (void __user *)arg); case PERF_EVENT_IOC_SET_BPF: - return perf_event_set_bpf_prog(event, arg); + { + struct bpf_prog *prog; + int err; + + prog = bpf_prog_get(arg); + if (IS_ERR(prog)) + return PTR_ERR(prog); + + err = perf_event_set_bpf_prog(event, prog); + if (err) { + bpf_prog_put(prog); + return err; + } + + return 0; + } case PERF_EVENT_IOC_PAUSE_OUTPUT: { struct perf_buffer *rb; @@ -9923,10 +9938,8 @@ static void bpf_overflow_handler(struct perf_event *event, event->orig_overflow_handler(event, data, regs); } -static int perf_event_set_bpf_handler(struct perf_event *event, u32 prog_fd) +static int perf_event_set_bpf_handler(struct perf_event *event, struct bpf_prog *prog) { - struct bpf_prog *prog; - if (event->overflow_handler_context) /* hw breakpoint or kernel counter */ return -EINVAL; @@ -9934,9 +9947,8 @@ static int perf_event_set_bpf_handler(struct perf_event *event, u32 prog_fd) if (event->prog) return -EEXIST; - prog = bpf_prog_get_type(prog_fd, BPF_PROG_TYPE_PERF_EVENT); - if (IS_ERR(prog)) - return PTR_ERR(prog); + if (prog->type != BPF_PROG_TYPE_PERF_EVENT) + return -EINVAL; if (event->attr.precise_ip && prog->call_get_stack && @@ -9952,7 +9964,6 @@ static int perf_event_set_bpf_handler(struct perf_event *event, u32 prog_fd) * attached to perf_sample_data, do not allow attaching BPF * program that calls bpf_get_[stack|stackid]. */ - bpf_prog_put(prog); return -EPROTO; } @@ -9974,7 +9985,7 @@ static void perf_event_free_bpf_handler(struct perf_event *event) bpf_prog_put(prog); } #else -static int perf_event_set_bpf_handler(struct perf_event *event, u32 prog_fd) +static int perf_event_set_bpf_handler(struct perf_event *event, struct bpf_prog *prog) { return -EOPNOTSUPP; } @@ -10002,14 +10013,12 @@ static inline bool perf_event_is_tracing(struct perf_event *event) return false; } -static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd) +static int perf_event_set_bpf_prog(struct perf_event *event, struct bpf_prog *prog) { bool is_kprobe, is_tracepoint, is_syscall_tp; - struct bpf_prog *prog; - int ret; if (!perf_event_is_tracing(event)) - return perf_event_set_bpf_handler(event, prog_fd); + return perf_event_set_bpf_handler(event, prog); is_kprobe = event->tp_event->flags & TRACE_EVENT_FL_UKPROBE; is_tracepoint = event->tp_event->flags & TRACE_EVENT_FL_TRACEPOINT; @@ -10018,38 +10027,24 @@ static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd) /* bpf programs can only be attached to u/kprobe or tracepoint */ return -EINVAL; - prog = bpf_prog_get(prog_fd); - if (IS_ERR(prog)) - return PTR_ERR(prog); - if ((is_kprobe && prog->type != BPF_PROG_TYPE_KPROBE) || (is_tracepoint && prog->type != BPF_PROG_TYPE_TRACEPOINT) || - (is_syscall_tp && prog->type != BPF_PROG_TYPE_TRACEPOINT)) { - /* valid fd, but invalid bpf program type */ - bpf_prog_put(prog); + (is_syscall_tp && prog->type != BPF_PROG_TYPE_TRACEPOINT)) return -EINVAL; - } /* Kprobe override only works for kprobes, not uprobes. */ if (prog->kprobe_override && - !(event->tp_event->flags & TRACE_EVENT_FL_KPROBE)) { - bpf_prog_put(prog); + !(event->tp_event->flags & TRACE_EVENT_FL_KPROBE)) return -EINVAL; - } if (is_tracepoint || is_syscall_tp) { int off = trace_event_get_offsets(event->tp_event); - if (prog->aux->max_ctx_offset > off) { - bpf_prog_put(prog); + if (prog->aux->max_ctx_offset > off) return -EACCES; - } } - ret = perf_event_attach_bpf_prog(event, prog); - if (ret) - bpf_prog_put(prog); - return ret; + return perf_event_attach_bpf_prog(event, prog); } static void perf_event_free_bpf_prog(struct perf_event *event) @@ -10071,7 +10066,7 @@ static void perf_event_free_filter(struct perf_event *event) { } -static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd) +static int perf_event_set_bpf_prog(struct perf_event *event, struct bpf_prog *prog) { return -ENOENT; }