From patchwork Wed Sep 23 17:46:27 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alan Maguire X-Patchwork-Id: 11795385 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 9FF7B92C for ; Wed, 23 Sep 2020 17:50:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7CEFA21BE5 for ; Wed, 23 Sep 2020 17:50:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="FEaIJX0t" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726720AbgIWRuM (ORCPT ); Wed, 23 Sep 2020 13:50:12 -0400 Received: from aserp2120.oracle.com ([141.146.126.78]:57756 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726413AbgIWRuK (ORCPT ); Wed, 23 Sep 2020 13:50:10 -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 08NHdJ2T078113; Wed, 23 Sep 2020 17:49:18 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=W65ZGoHediW1tGKJ28cfVTH/mnDXnEiOgdsTF56G2So=; b=FEaIJX0tanQZizkq46C9qey7G0Lh+B364o8nIr4gmjvMMZ0C/7I54aDZd0x0K5nKR4Zu 2tzMmpU5CFNS1SeqN4lv4g6D+dk+n+mBk3QrQmW5dyt9xd3Zq4kyg0FK5cMHMoagYAGX YIuhqKIliI43orXhGBiwJ2fGbZUAOrX8iki4x2hegTV4snVl/bHe2ah0W09Z0ClqkVpv ViXkeNbc3NWaiiAD+A6GtrNLXrG5VNoltBvNVPqksFQ61Y1f2w8V4b6R3HkhLeNLb3tg PAeaWYu2HowiAPrB7LeNlxCNRHdyGUvsiyaJmf3rKdPCpXgJ2aaSV4LSVAXnOfgjak5c tQ== Received: from userp3030.oracle.com (userp3030.oracle.com [156.151.31.80]) by aserp2120.oracle.com with ESMTP id 33q5rgja2j-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Wed, 23 Sep 2020 17:49:17 +0000 Received: from pps.filterd (userp3030.oracle.com [127.0.0.1]) by userp3030.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 08NHfQfL039965; Wed, 23 Sep 2020 17:47:17 GMT Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by userp3030.oracle.com with ESMTP id 33nux1gepb-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 23 Sep 2020 17:47:17 +0000 Received: from abhmp0017.oracle.com (abhmp0017.oracle.com [141.146.116.23]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id 08NHlF2x001008; Wed, 23 Sep 2020 17:47:15 GMT Received: from localhost.uk.oracle.com (/10.175.195.80) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Wed, 23 Sep 2020 10:47:15 -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, bpf@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, acme@kernel.org, Alan Maguire Subject: [PATCH v6 bpf-next 5/6] bpf: add bpf_seq_printf_btf helper Date: Wed, 23 Sep 2020 18:46:27 +0100 Message-Id: <1600883188-4831-6-git-send-email-alan.maguire@oracle.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1600883188-4831-1-git-send-email-alan.maguire@oracle.com> References: <1600883188-4831-1-git-send-email-alan.maguire@oracle.com> X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9753 signatures=668680 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 malwarescore=0 mlxscore=0 adultscore=0 bulkscore=0 mlxlogscore=999 phishscore=0 suspectscore=0 spamscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2009230135 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9753 signatures=668680 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 impostorscore=0 clxscore=1015 suspectscore=0 phishscore=0 malwarescore=0 priorityscore=1501 mlxlogscore=999 adultscore=0 bulkscore=0 mlxscore=0 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2009230135 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 | 10 ++++++++++ kernel/bpf/btf.c | 4 ++-- kernel/bpf/core.c | 1 + kernel/trace/bpf_trace.c | 33 +++++++++++++++++++++++++++++++++ tools/include/uapi/linux/bpf.h | 10 ++++++++++ 6 files changed, 58 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 c1675ad..c3231a8 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -3621,6 +3621,15 @@ 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 name or *ptr*->type_id as per + * bpf_snprintf_btf() above. *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), \ @@ -3773,6 +3782,7 @@ 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 94190ec..dfc8654 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -5316,8 +5316,8 @@ static __printf(2, 3) void btf_seq_show(struct btf_show *show, const char *fmt, va_end(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 61c274f8..e8fa1c0 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) @@ -1731,6 +1760,10 @@ 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 c1675ad..c3231a8 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -3621,6 +3621,15 @@ 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 name or *ptr*->type_id as per + * bpf_snprintf_btf() above. *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), \ @@ -3773,6 +3782,7 @@ 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