{"id":1238823,"url":"http://patchwork.ozlabs.org/api/patches/1238823/?format=json","web_url":"http://patchwork.ozlabs.org/project/netdev/patch/20200216193005.144157-13-jolsa@kernel.org/","project":{"id":7,"url":"http://patchwork.ozlabs.org/api/projects/7/?format=json","name":"Linux network development","link_name":"netdev","list_id":"netdev.vger.kernel.org","list_email":"netdev@vger.kernel.org","web_url":null,"scm_url":null,"webscm_url":null,"list_archive_url":"","list_archive_url_format":"","commit_url_format":""},"msgid":"<20200216193005.144157-13-jolsa@kernel.org>","list_archive_url":null,"date":"2020-02-16T19:29:59","name":"[12/18] bpf: Add trampolines to kallsyms","commit_ref":null,"pull_url":null,"state":"changes-requested","archived":false,"hash":"f20a423f14f22a893b761c4f8dfb8672e321c111","submitter":{"id":73687,"url":"http://patchwork.ozlabs.org/api/people/73687/?format=json","name":"Jiri Olsa","email":"jolsa@kernel.org"},"delegate":{"id":77147,"url":"http://patchwork.ozlabs.org/api/users/77147/?format=json","username":"bpf","first_name":"BPF","last_name":"Maintainers","email":"bpf@iogearbox.net"},"mbox":"http://patchwork.ozlabs.org/project/netdev/patch/20200216193005.144157-13-jolsa@kernel.org/mbox/","series":[{"id":158829,"url":"http://patchwork.ozlabs.org/api/series/158829/?format=json","web_url":"http://patchwork.ozlabs.org/project/netdev/list/?series=158829","date":"2020-02-16T19:29:47","name":"bpf: Add trampoline and dispatcher to /proc/kallsyms","version":1,"mbox":"http://patchwork.ozlabs.org/series/158829/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/1238823/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/1238823/checks/","tags":{},"related":[],"headers":{"Return-Path":"","X-Original-To":"incoming-bpf@patchwork.ozlabs.org","Delivered-To":"patchwork-incoming-bpf@bilbo.ozlabs.org","Authentication-Results":["ozlabs.org; spf=none (no SPF record)\n\tsmtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67;\n\thelo=vger.kernel.org; envelope-from=bpf-owner@vger.kernel.org;\n\treceiver=)","ozlabs.org;\n\tdmarc=fail (p=none dis=none) header.from=kernel.org"],"Received":["from vger.kernel.org (vger.kernel.org [209.132.180.67])\n\tby ozlabs.org (Postfix) with ESMTP id 48LHKt6KP2z9sP7\n\tfor ;\n\tMon, 17 Feb 2020 06:31:30 +1100 (AEDT)","(majordomo@vger.kernel.org) by vger.kernel.org via listexpand\n\tid S1727974AbgBPTba convert rfc822-to-8bit (ORCPT\n\t);\n\tSun, 16 Feb 2020 14:31:30 -0500","from us-smtp-1.mimecast.com ([207.211.31.81]:31798 \"EHLO\n\tus-smtp-delivery-1.mimecast.com\" rhost-flags-OK-OK-OK-FAIL)\n\tby vger.kernel.org with ESMTP id S1726036AbgBPTba (ORCPT\n\t); Sun, 16 Feb 2020 14:31:30 -0500","from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com\n\t[209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id\n\tus-mta-169-arYDL3jsP2Cs_HihbQ5YcA-1; Sun, 16 Feb 2020 14:31:25 -0500","from smtp.corp.redhat.com\n\t(int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11])\n\t(using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits))\n\t(No client certificate requested)\n\tby mimecast-mx01.redhat.com (Postfix) with ESMTPS id 070B48017CC;\n\tSun, 16 Feb 2020 19:31:23 +0000 (UTC)","from krava.redhat.com (ovpn-204-28.brq.redhat.com [10.40.204.28])\n\tby smtp.corp.redhat.com (Postfix) with ESMTP id 103E48AC5B;\n\tSun, 16 Feb 2020 19:31:17 +0000 (UTC)"],"From":"Jiri Olsa ","To":"Alexei Starovoitov ,\n\tDaniel Borkmann ","Cc":"netdev@vger.kernel.org, bpf@vger.kernel.org, Andrii Nakryiko\n\t, Yonghong Song , Song Liu\n\t, Martin KaFai Lau ,\n\tJakub Kicinski , David Miller ,\n\t=?utf-8?b?QmrDtnJuIFTDtnBlbA==?= ,\n\tJohn Fastabend , Jesper Dangaard Brouer\n\t, Arnaldo Carvalho de Melo ","Subject":"[PATCH 12/18] bpf: Add trampolines to kallsyms","Date":"Sun, 16 Feb 2020 20:29:59 +0100","Message-Id":"<20200216193005.144157-13-jolsa@kernel.org>","In-Reply-To":"<20200216193005.144157-1-jolsa@kernel.org>","References":"<20200216193005.144157-1-jolsa@kernel.org>","MIME-Version":"1.0","X-Scanned-By":"MIMEDefang 2.79 on 10.5.11.11","X-MC-Unique":"arYDL3jsP2Cs_HihbQ5YcA-1","X-Mimecast-Spam-Score":"0","X-Mimecast-Originator":"kernel.org","Content-Type":"text/plain; charset=WINDOWS-1252","Content-Transfer-Encoding":"8BIT","Sender":"bpf-owner@vger.kernel.org","Precedence":"bulk","List-ID":"","X-Mailing-List":"bpf@vger.kernel.org"},"content":"Adding trampolines to kallsyms. It's displayed as\n bpf_trampoline_ [bpf]\n\nwhere ID is the BTF id of the trampoline function.\n\nSigned-off-by: Jiri Olsa \n---\n include/linux/bpf.h | 3 +++\n kernel/bpf/trampoline.c | 38 +++++++++++++++++++++++++++++++++++++-\n 2 files changed, 40 insertions(+), 1 deletion(-)","diff":"diff --git a/include/linux/bpf.h b/include/linux/bpf.h\nindex 76934893bccf..c216af89254f 100644\n--- a/include/linux/bpf.h\n+++ b/include/linux/bpf.h\n@@ -502,6 +502,7 @@ struct bpf_trampoline {\n \t/* Executable image of trampoline */\n \tvoid *image;\n \tu64 selector;\n+\tstruct bpf_ksym ksym;\n };\n \n #define BPF_DISPATCHER_MAX 48 /* Fits in 2048B */\n@@ -573,6 +574,8 @@ struct bpf_image {\n #define BPF_IMAGE_SIZE (PAGE_SIZE - sizeof(struct bpf_image))\n bool is_bpf_image_address(unsigned long address);\n void *bpf_image_alloc(void);\n+void bpf_image_ksym_add(void *data, struct bpf_ksym *ksym);\n+void bpf_image_ksym_del(struct bpf_ksym *ksym);\n /* Called only from code, so there's no need for stubs. */\n void bpf_ksym_add(struct bpf_ksym *ksym);\n void bpf_ksym_del(struct bpf_ksym *ksym);\ndiff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c\nindex 6b264a92064b..4b0ae976a6eb 100644\n--- a/kernel/bpf/trampoline.c\n+++ b/kernel/bpf/trampoline.c\n@@ -5,6 +5,7 @@\n #include \n #include \n #include \n+#include \n \n /* dummy _ops. The verifier will operate on target program's ops. */\n const struct bpf_verifier_ops bpf_extension_verifier_ops = {\n@@ -96,6 +97,22 @@ bool is_bpf_image_address(unsigned long addr)\n \treturn ret;\n }\n \n+void bpf_image_ksym_add(void *data, struct bpf_ksym *ksym)\n+{\n+\tksym->start = (unsigned long) data;\n+\tksym->end = ksym->start + BPF_IMAGE_SIZE;\n+\tbpf_ksym_add(ksym);\n+\tperf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_BPF, ksym->start,\n+\t\t\t BPF_IMAGE_SIZE, false, ksym->name);\n+}\n+\n+void bpf_image_ksym_del(struct bpf_ksym *ksym)\n+{\n+\tbpf_ksym_del(ksym);\n+\tperf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_BPF, ksym->start,\n+\t\t\t BPF_IMAGE_SIZE, true, ksym->name);\n+}\n+\n struct bpf_trampoline *bpf_trampoline_lookup(u64 key)\n {\n \tstruct bpf_trampoline *tr;\n@@ -131,6 +148,7 @@ struct bpf_trampoline *bpf_trampoline_lookup(u64 key)\n \tfor (i = 0; i < BPF_TRAMP_MAX; i++)\n \t\tINIT_HLIST_HEAD(&tr->progs_hlist[i]);\n \ttr->image = image;\n+\tINIT_LIST_HEAD_RCU(&tr->ksym.lnode);\n out:\n \tmutex_unlock(&trampoline_mutex);\n \treturn tr;\n@@ -267,6 +285,14 @@ static enum bpf_tramp_prog_type bpf_attach_type_to_tramp(enum bpf_attach_type t)\n \t}\n }\n \n+static void bpf_trampoline_ksym_add(struct bpf_trampoline *tr)\n+{\n+\tstruct bpf_ksym *ksym = &tr->ksym;\n+\n+\tsnprintf(ksym->name, KSYM_NAME_LEN, \"bpf_trampoline_%llu\", tr->key);\n+\tbpf_image_ksym_add(tr->image, ksym);\n+}\n+\n int bpf_trampoline_link_prog(struct bpf_prog *prog)\n {\n \tenum bpf_tramp_prog_type kind;\n@@ -291,6 +317,10 @@ int bpf_trampoline_link_prog(struct bpf_prog *prog)\n \t\t\terr = -EBUSY;\n \t\t\tgoto out;\n \t\t}\n+\t\t/* With cnt == 0 image is not used (no symbol in kallsyms)\n+\t\t * and will not be used for BPF_PROG_TYPE_EXT prog type,\n+\t\t * so there's no symbol added for this case.\n+\t\t */\n \t\ttr->extension_prog = prog;\n \t\terr = bpf_arch_text_poke(tr->func.addr, BPF_MOD_JUMP, NULL,\n \t\t\t\t\t prog->bpf_func);\n@@ -311,7 +341,10 @@ int bpf_trampoline_link_prog(struct bpf_prog *prog)\n \tif (err) {\n \t\thlist_del(&prog->aux->tramp_hlist);\n \t\ttr->progs_cnt[kind]--;\n+\t\tgoto out;\n \t}\n+\tif (cnt == 0)\n+\t\tbpf_trampoline_ksym_add(tr);\n out:\n \tmutex_unlock(&tr->mutex);\n \treturn err;\n@@ -322,7 +355,7 @@ int bpf_trampoline_unlink_prog(struct bpf_prog *prog)\n {\n \tenum bpf_tramp_prog_type kind;\n \tstruct bpf_trampoline *tr;\n-\tint err;\n+\tint err, cnt;\n \n \ttr = prog->aux->trampoline;\n \tkind = bpf_attach_type_to_tramp(prog->expected_attach_type);\n@@ -336,6 +369,9 @@ int bpf_trampoline_unlink_prog(struct bpf_prog *prog)\n \t}\n \thlist_del(&prog->aux->tramp_hlist);\n \ttr->progs_cnt[kind]--;\n+\tcnt = tr->progs_cnt[BPF_TRAMP_FENTRY] + tr->progs_cnt[BPF_TRAMP_FEXIT];\n+\tif (cnt == 0)\n+\t\tbpf_image_ksym_del(&tr->ksym);\n \terr = bpf_trampoline_update(prog->aux->trampoline);\n out:\n \tmutex_unlock(&tr->mutex);\n","prefixes":["12/18"]}