From patchwork Tue Jun 23 07:08:00 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Song Liu X-Patchwork-Id: 1314942 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: incoming-bpf@patchwork.ozlabs.org Delivered-To: patchwork-incoming-bpf@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=bpf-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=reject dis=none) header.from=fb.com Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=fb.com header.i=@fb.com header.a=rsa-sha256 header.s=facebook header.b=VYFigv+8; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 49rcnS0RL2z9sSF for ; Tue, 23 Jun 2020 17:08:28 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731121AbgFWHI1 (ORCPT ); Tue, 23 Jun 2020 03:08:27 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:52482 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1731068AbgFWHI0 (ORCPT ); Tue, 23 Jun 2020 03:08:26 -0400 Received: from pps.filterd (m0001303.ppops.net [127.0.0.1]) by m0001303.ppops.net (8.16.0.42/8.16.0.42) with SMTP id 05N72GGm021664 for ; Tue, 23 Jun 2020 00:08:24 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding : content-type; s=facebook; bh=h9hzQRSnnqUfYEsZJwB4iiRNF8tazAWqAlkR8NtDjRg=; b=VYFigv+8yxk+VJcSOHQisEJZB9g4+UIDm6bbKIDVJ2cU8pGemj0ik3O5mzhouFQZW8j0 jr6/XWB4nsa6esofL2lPu2x4bO+m6A6TZu59qXTpFDoyHbf0WMSj/v/hlwYQIRcmM7gz XZ6IwS1rBnbTZn/mgcvYbIPvuubi42H/0aQ= Received: from maileast.thefacebook.com ([163.114.130.16]) by m0001303.ppops.net with ESMTP id 31se4nmn0p-5 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Tue, 23 Jun 2020 00:08:24 -0700 Received: from intmgw002.03.ash8.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:82::d) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1979.3; Tue, 23 Jun 2020 00:08:23 -0700 Received: by devbig006.ftw2.facebook.com (Postfix, from userid 4523) id AEC5B62E50B5; Tue, 23 Jun 2020 00:08:16 -0700 (PDT) Smtp-Origin-Hostprefix: devbig From: Song Liu Smtp-Origin-Hostname: devbig006.ftw2.facebook.com To: , CC: , , , , , Song Liu Smtp-Origin-Cluster: ftw2c04 Subject: [PATCH bpf-next 1/3] bpf: introduce helper bpf_get_task_stack_trace() Date: Tue, 23 Jun 2020 00:08:00 -0700 Message-ID: <20200623070802.2310018-2-songliubraving@fb.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200623070802.2310018-1-songliubraving@fb.com> References: <20200623070802.2310018-1-songliubraving@fb.com> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.216, 18.0.687 definitions=2020-06-23_04:2020-06-22,2020-06-23 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 bulkscore=0 impostorscore=0 malwarescore=0 phishscore=0 mlxlogscore=999 spamscore=0 clxscore=1015 mlxscore=0 lowpriorityscore=0 priorityscore=1501 cotscore=-2147483648 adultscore=0 suspectscore=9 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2004280000 definitions=main-2006230055 X-FB-Internal: deliver Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org This helper can be used with bpf_iter__task to dump all /proc/*/stack to a seq_file. Signed-off-by: Song Liu --- include/uapi/linux/bpf.h | 10 +++++++++- kernel/trace/bpf_trace.c | 21 +++++++++++++++++++++ scripts/bpf_helpers_doc.py | 2 ++ tools/include/uapi/linux/bpf.h | 10 +++++++++- 4 files changed, 41 insertions(+), 2 deletions(-) -- 2.24.1 diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 19684813faaed..a30416b822fe3 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -3252,6 +3252,13 @@ union bpf_attr { * case of **BPF_CSUM_LEVEL_QUERY**, the current skb->csum_level * is returned or the error code -EACCES in case the skb is not * subject to CHECKSUM_UNNECESSARY. + * + * int bpf_get_task_stack_trace(struct task_struct *task, void *entries, u32 size) + * Description + * Save a task stack trace into array *entries*. This is a wrapper + * over stack_trace_save_tsk(). + * Return + * Number of trace entries stored. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -3389,7 +3396,8 @@ union bpf_attr { FN(ringbuf_submit), \ FN(ringbuf_discard), \ FN(ringbuf_query), \ - FN(csum_level), + FN(csum_level), \ + FN(get_task_stack_trace), /* integer value in 'imm' field of BPF_CALL instruction selects which helper * function eBPF program intends to call diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index e729c9e587a07..2c13bcb5c2bce 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -1488,6 +1488,23 @@ static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = { .arg4_type = ARG_ANYTHING, }; +BPF_CALL_3(bpf_get_task_stack_trace, struct task_struct *, task, + void *, entries, u32, size) +{ + return stack_trace_save_tsk(task, (unsigned long *)entries, size, 0); +} + +static int bpf_get_task_stack_trace_btf_ids[5]; +static const struct bpf_func_proto bpf_get_task_stack_trace_proto = { + .func = bpf_get_task_stack_trace, + .gpl_only = true, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_BTF_ID, + .arg2_type = ARG_PTR_TO_MEM, + .arg3_type = ARG_CONST_SIZE_OR_ZERO, + .btf_id = bpf_get_task_stack_trace_btf_ids, +}; + static const struct bpf_func_proto * raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) { @@ -1521,6 +1538,10 @@ tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return prog->expected_attach_type == BPF_TRACE_ITER ? &bpf_seq_write_proto : NULL; + case BPF_FUNC_get_task_stack_trace: + return prog->expected_attach_type == BPF_TRACE_ITER ? + &bpf_get_task_stack_trace_proto : + NULL; default: return raw_tp_prog_func_proto(func_id, prog); } diff --git a/scripts/bpf_helpers_doc.py b/scripts/bpf_helpers_doc.py index 91fa668fa8602..a8783d668c5b7 100755 --- a/scripts/bpf_helpers_doc.py +++ b/scripts/bpf_helpers_doc.py @@ -421,6 +421,7 @@ class PrinterHelpers(Printer): 'struct sockaddr', 'struct tcphdr', 'struct seq_file', + 'struct task_struct', 'struct __sk_buff', 'struct sk_msg_md', @@ -458,6 +459,7 @@ class PrinterHelpers(Printer): 'struct sockaddr', 'struct tcphdr', 'struct seq_file', + 'struct task_struct', } mapped_types = { 'u8': '__u8', diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 19684813faaed..a30416b822fe3 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -3252,6 +3252,13 @@ union bpf_attr { * case of **BPF_CSUM_LEVEL_QUERY**, the current skb->csum_level * is returned or the error code -EACCES in case the skb is not * subject to CHECKSUM_UNNECESSARY. + * + * int bpf_get_task_stack_trace(struct task_struct *task, void *entries, u32 size) + * Description + * Save a task stack trace into array *entries*. This is a wrapper + * over stack_trace_save_tsk(). + * Return + * Number of trace entries stored. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -3389,7 +3396,8 @@ union bpf_attr { FN(ringbuf_submit), \ FN(ringbuf_discard), \ FN(ringbuf_query), \ - FN(csum_level), + FN(csum_level), \ + FN(get_task_stack_trace), /* integer value in 'imm' field of BPF_CALL instruction selects which helper * function eBPF program intends to call From patchwork Tue Jun 23 07:08:01 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Song Liu X-Patchwork-Id: 1314946 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=reject dis=none) header.from=fb.com Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=fb.com header.i=@fb.com header.a=rsa-sha256 header.s=facebook header.b=LPJ22L+F; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 49rcnX10Kxz9sRh for ; Tue, 23 Jun 2020 17:08:32 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731251AbgFWHIb (ORCPT ); Tue, 23 Jun 2020 03:08:31 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:62746 "EHLO mx0b-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731143AbgFWHI2 (ORCPT ); Tue, 23 Jun 2020 03:08:28 -0400 Received: from pps.filterd (m0109332.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 05N74aJ3024010 for ; Tue, 23 Jun 2020 00:08:26 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding : content-type; s=facebook; bh=G8U8wLrivL4Bm9XBrSH1qxyAz1VKRcKWF+DdWmgC89Y=; b=LPJ22L+FI8aKXka1ibGAObYe4nxbwiVZzzHwFNj9Jrrc2xgKBaVjzFmAYR3G3AIS/D8M JCyq3zjepc48YpFDZJOnb2cXvCYfkbySe1ttTrqEJWLQyrFQsVPmAKyrt7Hy0BntvFSd PeF/7EcffmmyRDPppgzZw1C1B/abZ+yoWc0= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com with ESMTP id 31sg6scax3-2 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Tue, 23 Jun 2020 00:08:26 -0700 Received: from intmgw003.03.ash8.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:82::e) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1979.3; Tue, 23 Jun 2020 00:08:25 -0700 Received: by devbig006.ftw2.facebook.com (Postfix, from userid 4523) id BD84362E50B5; Tue, 23 Jun 2020 00:08:20 -0700 (PDT) Smtp-Origin-Hostprefix: devbig From: Song Liu Smtp-Origin-Hostname: devbig006.ftw2.facebook.com To: , CC: , , , , , Song Liu Smtp-Origin-Cluster: ftw2c04 Subject: [PATCH bpf-next 2/3] bpf: allow %pB in bpf_seq_printf() Date: Tue, 23 Jun 2020 00:08:01 -0700 Message-ID: <20200623070802.2310018-3-songliubraving@fb.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200623070802.2310018-1-songliubraving@fb.com> References: <20200623070802.2310018-1-songliubraving@fb.com> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.216,18.0.687 definitions=2020-06-23_04:2020-06-22,2020-06-23 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 mlxscore=0 bulkscore=0 malwarescore=0 adultscore=0 mlxlogscore=803 lowpriorityscore=0 phishscore=0 spamscore=0 clxscore=1015 priorityscore=1501 suspectscore=8 impostorscore=0 cotscore=-2147483648 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2004280000 definitions=main-2006230055 X-FB-Internal: deliver Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org This makes it easy to dump stack trace with bpf_seq_printf(). Signed-off-by: Song Liu --- kernel/trace/bpf_trace.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 2c13bcb5c2bce..ced3176801ae8 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -636,7 +636,8 @@ BPF_CALL_5(bpf_seq_printf, struct seq_file *, m, char *, fmt, u32, fmt_size, if (fmt[i] == 'p') { if (fmt[i + 1] == 0 || fmt[i + 1] == 'K' || - fmt[i + 1] == 'x') { + fmt[i + 1] == 'x' || + fmt[i + 1] == 'B') { /* just kernel pointers */ params[fmt_cnt] = args[fmt_cnt]; fmt_cnt++; From patchwork Tue Jun 23 07:08:02 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Song Liu X-Patchwork-Id: 1314944 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: incoming-bpf@patchwork.ozlabs.org Delivered-To: patchwork-incoming-bpf@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=bpf-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=reject dis=none) header.from=fb.com Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=fb.com header.i=@fb.com header.a=rsa-sha256 header.s=facebook header.b=Cxmm6F5X; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 49rcnV4Wjqz9sRW for ; Tue, 23 Jun 2020 17:08:30 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730781AbgFWHI3 (ORCPT ); Tue, 23 Jun 2020 03:08:29 -0400 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:27638 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731163AbgFWHI2 (ORCPT ); Tue, 23 Jun 2020 03:08:28 -0400 Received: from pps.filterd (m0044012.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 05N76T7u005343 for ; Tue, 23 Jun 2020 00:08:27 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding : content-type; s=facebook; bh=n7+ccP8jkYjwvnQfwcVf+CiZN1OfCu4uUc86RW/6OMQ=; b=Cxmm6F5Xgu9XPMOioiIWa58UL4l+B4I+1aLfMvGu6jVk+3mgPupnvD3bqJDwTajQtdRE Hd/cCCqe/bzGW0U6hfc9HKw0G3qXajCq3es9D3yXEnAeDKHqZzkBYOE6KHwbURlwoMO1 fWkewyt9TOEMMD9lLIloRCe0m7/7ERjmD/I= Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com with ESMTP id 31t2qq1k2x-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Tue, 23 Jun 2020 00:08:27 -0700 Received: from intmgw003.08.frc2.facebook.com (2620:10d:c085:108::8) by mail.thefacebook.com (2620:10d:c085:21d::4) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1979.3; Tue, 23 Jun 2020 00:08:26 -0700 Received: by devbig006.ftw2.facebook.com (Postfix, from userid 4523) id 5CBD562E50B5; Tue, 23 Jun 2020 00:08:24 -0700 (PDT) Smtp-Origin-Hostprefix: devbig From: Song Liu Smtp-Origin-Hostname: devbig006.ftw2.facebook.com To: , CC: , , , , , Song Liu Smtp-Origin-Cluster: ftw2c04 Subject: [PATCH bpf-next 3/3] selftests/bpf: add bpf_iter test with bpf_get_task_stack_trace() Date: Tue, 23 Jun 2020 00:08:02 -0700 Message-ID: <20200623070802.2310018-4-songliubraving@fb.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200623070802.2310018-1-songliubraving@fb.com> References: <20200623070802.2310018-1-songliubraving@fb.com> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.216, 18.0.687 definitions=2020-06-23_04:2020-06-22,2020-06-23 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 lowpriorityscore=0 priorityscore=1501 spamscore=0 cotscore=-2147483648 adultscore=0 malwarescore=0 clxscore=1015 impostorscore=0 phishscore=0 mlxscore=0 bulkscore=0 mlxlogscore=999 suspectscore=8 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2004280000 definitions=main-2006230055 X-FB-Internal: deliver Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org The new test is similar to other bpf_iter tests. Signed-off-by: Song Liu --- .../selftests/bpf/prog_tests/bpf_iter.c | 17 +++++++ .../selftests/bpf/progs/bpf_iter_task_stack.c | 50 +++++++++++++++++++ 2 files changed, 67 insertions(+) create mode 100644 tools/testing/selftests/bpf/progs/bpf_iter_task_stack.c diff --git a/tools/testing/selftests/bpf/prog_tests/bpf_iter.c b/tools/testing/selftests/bpf/prog_tests/bpf_iter.c index 87c29dde1cf96..baa83328f810d 100644 --- a/tools/testing/selftests/bpf/prog_tests/bpf_iter.c +++ b/tools/testing/selftests/bpf/prog_tests/bpf_iter.c @@ -5,6 +5,7 @@ #include "bpf_iter_netlink.skel.h" #include "bpf_iter_bpf_map.skel.h" #include "bpf_iter_task.skel.h" +#include "bpf_iter_task_stack.skel.h" #include "bpf_iter_task_file.skel.h" #include "bpf_iter_test_kern1.skel.h" #include "bpf_iter_test_kern2.skel.h" @@ -106,6 +107,20 @@ static void test_task(void) bpf_iter_task__destroy(skel); } +static void test_task_stack(void) +{ + struct bpf_iter_task_stack *skel; + + skel = bpf_iter_task_stack__open_and_load(); + if (CHECK(!skel, "bpf_iter_task_stack__open_and_load", + "skeleton open_and_load failed\n")) + return; + + do_dummy_read(skel->progs.dump_task_stack); + + bpf_iter_task_stack__destroy(skel); +} + static void test_task_file(void) { struct bpf_iter_task_file *skel; @@ -392,6 +407,8 @@ void test_bpf_iter(void) test_bpf_map(); if (test__start_subtest("task")) test_task(); + if (test__start_subtest("task_stack")) + test_task_stack(); if (test__start_subtest("task_file")) test_task_file(); if (test__start_subtest("anon")) diff --git a/tools/testing/selftests/bpf/progs/bpf_iter_task_stack.c b/tools/testing/selftests/bpf/progs/bpf_iter_task_stack.c new file mode 100644 index 0000000000000..4fc939e0fca77 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/bpf_iter_task_stack.c @@ -0,0 +1,50 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2020 Facebook */ +/* "undefine" structs in vmlinux.h, because we "override" them below */ +#define bpf_iter_meta bpf_iter_meta___not_used +#define bpf_iter__task bpf_iter__task___not_used +#include "vmlinux.h" +#undef bpf_iter_meta +#undef bpf_iter__task +#include +#include + +char _license[] SEC("license") = "GPL"; + +struct bpf_iter_meta { + struct seq_file *seq; + __u64 session_id; + __u64 seq_num; +} __attribute__((preserve_access_index)); + +struct bpf_iter__task { + struct bpf_iter_meta *meta; + struct task_struct *task; +} __attribute__((preserve_access_index)); + +#define MAX_STACK_TRACE_DEPTH 64 +unsigned long entries[MAX_STACK_TRACE_DEPTH]; + +SEC("iter/task") +int dump_task_stack(struct bpf_iter__task *ctx) +{ + struct seq_file *seq = ctx->meta->seq; + struct task_struct *task = ctx->task; + unsigned int i, num_entries; + + if (task == (void *)0) + return 0; + + num_entries = bpf_get_task_stack_trace(task, entries, MAX_STACK_TRACE_DEPTH); + + BPF_SEQ_PRINTF(seq, "pid: %8u\n", task->pid); + + for (i = 0; i < MAX_STACK_TRACE_DEPTH; i++) { + if (num_entries > i) + BPF_SEQ_PRINTF(seq, "[<0>] %pB\n", (void *)entries[i]); + } + + BPF_SEQ_PRINTF(seq, "\n"); + + return 0; +}