From patchwork Thu May 19 20:20:32 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Song Liu X-Patchwork-Id: 12856016 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 1AE3AC433EF for ; Thu, 19 May 2022 20:23:41 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 3AD5E6B007B; Thu, 19 May 2022 16:23:39 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 30CA46B0078; Thu, 19 May 2022 16:23:39 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 161296B007B; Thu, 19 May 2022 16:23:39 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 000DA6B0075 for ; Thu, 19 May 2022 16:23:38 -0400 (EDT) Received: from smtpin20.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id CDB6921276 for ; Thu, 19 May 2022 20:23:33 +0000 (UTC) X-FDA: 79483617906.20.BA9DE9B Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by imf08.hostedemail.com (Postfix) with ESMTP id D4B9816000B for ; Thu, 19 May 2022 20:23:14 +0000 (UTC) Received: from pps.filterd (m0109333.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 24JFGDpX012983 for ; Thu, 19 May 2022 13:23:32 -0700 Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3g4d82agfs-5 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Thu, 19 May 2022 13:23:32 -0700 Received: from twshared0725.22.frc3.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 15.1.2375.28; Thu, 19 May 2022 13:23:28 -0700 Received: by devbig932.frc1.facebook.com (Postfix, from userid 4523) id C3F337D58F64; Thu, 19 May 2022 13:20:49 -0700 (PDT) From: Song Liu To: , , CC: , , , , , , , Song Liu Subject: [PATCH v2 bpf-next 3/8] bpf: introduce bpf_arch_text_invalidate for bpf_prog_pack Date: Thu, 19 May 2022 13:20:32 -0700 Message-ID: <20220519202037.2401584-4-song@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220519202037.2401584-1-song@kernel.org> References: <20220519202037.2401584-1-song@kernel.org> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-GUID: PoYpddzZKa7RZMSQKGUV081DaJkCeNSm X-Proofpoint-ORIG-GUID: PoYpddzZKa7RZMSQKGUV081DaJkCeNSm 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=2022-05-19_06,2022-05-19_03,2022-02-23_01 X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: D4B9816000B Authentication-Results: imf08.hostedemail.com; dkim=none; spf=none (imf08.hostedemail.com: domain of "prvs=61387cfd06=songliubraving@fb.com" has no SPF policy when checking 67.231.145.42) smtp.mailfrom="prvs=61387cfd06=songliubraving@fb.com"; dmarc=fail reason="No valid SPF, No valid DKIM" header.from=kernel.org (policy=none) X-Rspam-User: X-Stat-Signature: o7dno474b81it7rwzsri9wxwtt41q8hr X-HE-Tag: 1652991794-567895 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 c107392b0ba7..f6dfa416f892 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -2364,6 +2364,7 @@ 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);