From patchwork Mon Sep 28 11:31:09 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alan Maguire X-Patchwork-Id: 11803479 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 5F9011580 for ; Mon, 28 Sep 2020 11:34:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 36DB7221EC for ; Mon, 28 Sep 2020 11:34:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="To9NJ1dS" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726547AbgI1Lev (ORCPT ); Mon, 28 Sep 2020 07:34:51 -0400 Received: from aserp2120.oracle.com ([141.146.126.78]:48614 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726465AbgI1Lev (ORCPT ); Mon, 28 Sep 2020 07:34:51 -0400 Received: from pps.filterd (aserp2120.oracle.com [127.0.0.1]) by aserp2120.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 08SBXSWL171212; Mon, 28 Sep 2020 11:33:28 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id : in-reply-to : references; s=corp-2020-01-29; bh=ls5EWukwLTwEEeJB12YgOzvMVsP+dk+LjF2XTI0JFPw=; b=To9NJ1dSDnq9L+l5X5syK0JI9VcLP4BI48u9kn3fsZq1cfcesHaMSsg4Ljr/iM3Yut0o y08Op+sCSCXb7+6sHLwHwK9aQcB4X2MwdQqRktScs/QWixcf4/EYSnaI23n3MPljiQoT b7FXYXWdyhNArKddgyYPWSfnVG0YAxNrYH0B2UpLPDeivGtjU56H2B8nedYWQRpQ+zgc qopV2M/5TD7UzD535ZQTbkixLX2hqGDaqgx9tVSwNu6yV5nWv9m95zyL0VBkCyntS9Kp j6HGtpGsGzz5OfpCXMz6MYQ3RxxS/GqGlepc444QFlcFutaTuTjFtuq7ven0HVEtJCf5 gw== Received: from userp3020.oracle.com (userp3020.oracle.com [156.151.31.79]) by aserp2120.oracle.com with ESMTP id 33swkkmetj-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Mon, 28 Sep 2020 11:33:28 +0000 Received: from pps.filterd (userp3020.oracle.com [127.0.0.1]) by userp3020.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 08SBUffL136931; Mon, 28 Sep 2020 11:33:23 GMT Received: from userv0121.oracle.com (userv0121.oracle.com [156.151.31.72]) by userp3020.oracle.com with ESMTP id 33tfdpx811-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 28 Sep 2020 11:33:23 +0000 Received: from abhmp0006.oracle.com (abhmp0006.oracle.com [141.146.116.12]) by userv0121.oracle.com (8.14.4/8.13.8) with ESMTP id 08SBXLWl009554; Mon, 28 Sep 2020 11:33:21 GMT Received: from localhost.uk.oracle.com (/10.175.167.231) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Mon, 28 Sep 2020 04:33:21 -0700 From: Alan Maguire To: ast@kernel.org, daniel@iogearbox.net, andriin@fb.com, yhs@fb.com Cc: linux@rasmusvillemoes.dk, andriy.shevchenko@linux.intel.com, pmladek@suse.com, kafai@fb.com, songliubraving@fb.com, john.fastabend@gmail.com, kpsingh@chromium.org, shuah@kernel.org, rdna@fb.com, scott.branden@broadcom.com, quentin@isovalent.com, cneirabustos@gmail.com, jakub@cloudflare.com, mingo@redhat.com, rostedt@goodmis.org, acme@kernel.org, bpf@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, Alan Maguire Subject: [PATCH v7 bpf-next 7/8] bpf: add bpf_seq_printf_btf helper Date: Mon, 28 Sep 2020 12:31:09 +0100 Message-Id: <1601292670-1616-8-git-send-email-alan.maguire@oracle.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1601292670-1616-1-git-send-email-alan.maguire@oracle.com> References: <1601292670-1616-1-git-send-email-alan.maguire@oracle.com> X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9757 signatures=668680 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 mlxlogscore=999 phishscore=0 adultscore=0 malwarescore=0 spamscore=0 mlxscore=0 bulkscore=0 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2009280093 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9757 signatures=668680 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 malwarescore=0 mlxscore=0 phishscore=0 suspectscore=0 mlxlogscore=999 clxscore=1015 priorityscore=1501 impostorscore=0 lowpriorityscore=0 bulkscore=0 spamscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2009280094 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org A helper is added to allow seq file writing of kernel data structures using vmlinux BTF. Its signature is long bpf_seq_printf_btf(struct seq_file *m, struct btf_ptr *ptr, u32 btf_ptr_size, u64 flags); Flags and struct btf_ptr definitions/use are identical to the bpf_snprintf_btf helper, and the helper returns 0 on success or a negative error value. Suggested-by: Alexei Starovoitov Signed-off-by: Alan Maguire --- include/linux/btf.h | 2 ++ include/uapi/linux/bpf.h | 9 +++++++++ kernel/bpf/btf.c | 4 ++-- kernel/bpf/core.c | 1 + kernel/trace/bpf_trace.c | 33 +++++++++++++++++++++++++++++++++ tools/include/uapi/linux/bpf.h | 9 +++++++++ 6 files changed, 56 insertions(+), 2 deletions(-) diff --git a/include/linux/btf.h b/include/linux/btf.h index 3e5cdc2..024e16f 100644 --- a/include/linux/btf.h +++ b/include/linux/btf.h @@ -68,6 +68,8 @@ const struct btf_type *btf_type_id_size(const struct btf *btf, void btf_type_seq_show(const struct btf *btf, u32 type_id, void *obj, struct seq_file *m); +int btf_type_seq_show_flags(const struct btf *btf, u32 type_id, void *obj, + struct seq_file *m, u64 flags); /* * Copy len bytes of string representation of obj of BTF type_id into buf. diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index fcafe80..82817c4 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -3623,6 +3623,14 @@ struct bpf_stack_build_id { * The number of bytes that were written (or would have been * written if output had to be truncated due to string size), * or a negative error in cases of failure. + * + * long bpf_seq_printf_btf(struct seq_file *m, struct btf_ptr *ptr, u32 ptr_size, u64 flags) + * Description + * Use BTF to write to seq_write a string representation of + * *ptr*->ptr, using *ptr*->type_id as per bpf_snprintf_btf(). + * *flags* are identical to those used for bpf_snprintf_btf. + * Return + * 0 on success or a negative error in case of failure. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -3775,6 +3783,7 @@ struct bpf_stack_build_id { FN(d_path), \ FN(copy_from_user), \ FN(snprintf_btf), \ + FN(seq_printf_btf), \ /* */ /* integer value in 'imm' field of BPF_CALL instruction selects which helper diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index be5acf6..99e307a 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -5346,8 +5346,8 @@ static void btf_seq_show(struct btf_show *show, const char *fmt, seq_vprintf((struct seq_file *)show->target, fmt, args); } -static int btf_type_seq_show_flags(const struct btf *btf, u32 type_id, - void *obj, struct seq_file *m, u64 flags) +int btf_type_seq_show_flags(const struct btf *btf, u32 type_id, + void *obj, struct seq_file *m, u64 flags) { struct btf_show sseq; diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 403fb23..c4ba45f 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -2217,6 +2217,7 @@ void bpf_user_rnd_init_once(void) const struct bpf_func_proto bpf_get_local_storage_proto __weak; const struct bpf_func_proto bpf_get_ns_current_pid_tgid_proto __weak; const struct bpf_func_proto bpf_snprintf_btf_proto __weak; +const struct bpf_func_proto bpf_seq_printf_btf_proto __weak; const struct bpf_func_proto * __weak bpf_get_trace_printk_proto(void) { diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 983cbd3..6ac254e 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -71,6 +71,10 @@ static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name) u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); u64 bpf_get_stack(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); +static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size, + u64 flags, const struct btf **btf, + s32 *btf_id); + /** * trace_call_bpf - invoke BPF program * @call: tracepoint event @@ -776,6 +780,31 @@ struct bpf_seq_printf_buf { .arg3_type = ARG_CONST_SIZE_OR_ZERO, }; +BPF_CALL_4(bpf_seq_printf_btf, struct seq_file *, m, struct btf_ptr *, ptr, + u32, btf_ptr_size, u64, flags) +{ + const struct btf *btf; + s32 btf_id; + int ret; + + ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id); + if (ret) + return ret; + + return btf_type_seq_show_flags(btf, btf_id, ptr->ptr, m, flags); +} + +static const struct bpf_func_proto bpf_seq_printf_btf_proto = { + .func = bpf_seq_printf_btf, + .gpl_only = true, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_BTF_ID, + .arg1_btf_id = &btf_seq_file_ids[0], + .arg2_type = ARG_PTR_TO_MEM, + .arg3_type = ARG_CONST_SIZE_OR_ZERO, + .arg4_type = ARG_ANYTHING, +}; + static __always_inline int get_map_perf_counter(struct bpf_map *map, u64 flags, u64 *value, u64 *enabled, u64 *running) @@ -1695,6 +1724,10 @@ static void put_bpf_raw_tp_regs(void) return prog->expected_attach_type == BPF_TRACE_ITER ? &bpf_seq_write_proto : NULL; + case BPF_FUNC_seq_printf_btf: + return prog->expected_attach_type == BPF_TRACE_ITER ? + &bpf_seq_printf_btf_proto : + NULL; case BPF_FUNC_d_path: return &bpf_d_path_proto; default: diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index fcafe80..82817c4 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -3623,6 +3623,14 @@ struct bpf_stack_build_id { * The number of bytes that were written (or would have been * written if output had to be truncated due to string size), * or a negative error in cases of failure. + * + * long bpf_seq_printf_btf(struct seq_file *m, struct btf_ptr *ptr, u32 ptr_size, u64 flags) + * Description + * Use BTF to write to seq_write a string representation of + * *ptr*->ptr, using *ptr*->type_id as per bpf_snprintf_btf(). + * *flags* are identical to those used for bpf_snprintf_btf. + * Return + * 0 on success or a negative error in case of failure. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -3775,6 +3783,7 @@ struct bpf_stack_build_id { FN(d_path), \ FN(copy_from_user), \ FN(snprintf_btf), \ + FN(seq_printf_btf), \ /* */ /* integer value in 'imm' field of BPF_CALL instruction selects which helper