From patchwork Fri May 20 23:57:53 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Song Liu X-Patchwork-Id: 12857580 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id B83C7C433F5 for ; Sat, 21 May 2022 00:00:38 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 64B2C6B0074; Fri, 20 May 2022 20:00:37 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 5D4BC6B0075; Fri, 20 May 2022 20:00:37 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 425076B0078; Fri, 20 May 2022 20:00:37 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 1B3066B0075 for ; Fri, 20 May 2022 20:00:37 -0400 (EDT) Received: from smtpin03.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id E680132E3B for ; Sat, 21 May 2022 00:00:36 +0000 (UTC) X-FDA: 79487793672.03.53578A4 Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by imf26.hostedemail.com (Postfix) with ESMTP id E1CF114000C for ; Sat, 21 May 2022 00:00:32 +0000 (UTC) Received: from pps.filterd (m0109334.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 24KMsIZu029543 for ; Fri, 20 May 2022 17:00:35 -0700 Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3g5xexfqxf-3 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Fri, 20 May 2022 17:00:35 -0700 Received: from twshared24024.25.frc3.facebook.com (2620:10d:c085:208::11) by mail.thefacebook.com (2620:10d:c085:11d::6) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.28; Fri, 20 May 2022 17:00:33 -0700 Received: by devbig932.frc1.facebook.com (Postfix, from userid 4523) id A9C727E221E7; Fri, 20 May 2022 16:58:14 -0700 (PDT) From: Song Liu To: , , CC: , , , , , , , Song Liu Subject: [PATCH v4 bpf-next 3/8] bpf: introduce bpf_arch_text_invalidate for bpf_prog_pack Date: Fri, 20 May 2022 16:57:53 -0700 Message-ID: <20220520235758.1858153-4-song@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220520235758.1858153-1-song@kernel.org> References: <20220520235758.1858153-1-song@kernel.org> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-ORIG-GUID: VBgU7iln5p8oD2OIIZACvTZaycHBLTJ9 X-Proofpoint-GUID: VBgU7iln5p8oD2OIIZACvTZaycHBLTJ9 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.874,Hydra:6.0.486,FMLib:17.11.64.514 definitions=2022-05-20_08,2022-05-20_02,2022-02-23_01 X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: E1CF114000C X-Rspam-User: Authentication-Results: imf26.hostedemail.com; dkim=none; dmarc=fail reason="No valid SPF, No valid DKIM" header.from=kernel.org (policy=none); spf=none (imf26.hostedemail.com: domain of "prvs=6140678c23=songliubraving@fb.com" has no SPF policy when checking 67.231.145.42) smtp.mailfrom="prvs=6140678c23=songliubraving@fb.com" X-Stat-Signature: tfcruancnfxpab8e7f84eoigi4dyskhb X-HE-Tag: 1653091232-760415 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Introduce bpf_arch_text_invalidate and use it to fill unused part of the bpf_prog_pack with illegal instructions when a BPF program is freed. Signed-off-by: Song Liu --- arch/x86/net/bpf_jit_comp.c | 5 +++++ include/linux/bpf.h | 1 + kernel/bpf/core.c | 8 ++++++++ 3 files changed, 14 insertions(+) diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c index a2b6d197c226..f298b18a9a3d 100644 --- a/arch/x86/net/bpf_jit_comp.c +++ b/arch/x86/net/bpf_jit_comp.c @@ -228,6 +228,11 @@ static void jit_fill_hole(void *area, unsigned int size) memset(area, 0xcc, size); } +int bpf_arch_text_invalidate(void *dst, size_t len) +{ + return IS_ERR_OR_NULL(text_poke_set(dst, 0xcc, len)); +} + struct jit_context { int cleanup_addr; /* Epilogue code offset */ diff --git a/include/linux/bpf.h b/include/linux/bpf.h index cc4d5e394031..a9b1875212f6 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -2365,6 +2365,7 @@ int bpf_arch_text_poke(void *ip, enum bpf_text_poke_type t, void *addr1, void *addr2); void *bpf_arch_text_copy(void *dst, void *src, size_t len); +int bpf_arch_text_invalidate(void *dst, size_t len); struct btf_id_set; bool btf_id_set_contains(const struct btf_id_set *set, u32 id); diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 2d0c9d4696ad..cacd8684c3c4 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -968,6 +968,9 @@ static void bpf_prog_pack_free(struct bpf_binary_header *hdr) nbits = BPF_PROG_SIZE_TO_NBITS(hdr->size); pos = ((unsigned long)hdr - (unsigned long)pack_ptr) >> BPF_PROG_CHUNK_SHIFT; + WARN_ONCE(bpf_arch_text_invalidate(hdr, hdr->size), + "bpf_prog_pack bug: missing bpf_arch_text_invalidate?\n"); + bitmap_clear(pack->bitmap, pos, nbits); if (bitmap_find_next_zero_area(pack->bitmap, bpf_prog_chunk_count(), 0, bpf_prog_chunk_count(), 0) == 0) { @@ -2740,6 +2743,11 @@ void * __weak bpf_arch_text_copy(void *dst, void *src, size_t len) return ERR_PTR(-ENOTSUPP); } +int __weak bpf_arch_text_invalidate(void *dst, size_t len) +{ + return -ENOTSUPP; +} + DEFINE_STATIC_KEY_FALSE(bpf_stats_enabled_key); EXPORT_SYMBOL(bpf_stats_enabled_key);