From mboxrd@z Thu Jan 1 00:00:00 1970 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 56ECEC43219 for ; Thu, 17 Nov 2022 20:23:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232126AbiKQUXx convert rfc822-to-8bit (ORCPT ); Thu, 17 Nov 2022 15:23:53 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59270 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230287AbiKQUXq (ORCPT ); Thu, 17 Nov 2022 15:23:46 -0500 Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DFCF9205F9 for ; Thu, 17 Nov 2022 12:23:44 -0800 (PST) Received: from pps.filterd (m0044010.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 2AHHHFHc012051 for ; Thu, 17 Nov 2022 12:23:44 -0800 Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3kws7g1kss-7 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Thu, 17 Nov 2022 12:23:44 -0800 Received: from twshared13940.35.frc1.facebook.com (2620:10d:c085:208::f) by mail.thefacebook.com (2620:10d:c085:21d::6) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Thu, 17 Nov 2022 12:23:41 -0800 Received: by devbig932.frc1.facebook.com (Postfix, from userid 4523) id A3641FF17605; Thu, 17 Nov 2022 12:23:36 -0800 (PST) From: Song Liu To: , CC: , , , , , , , Song Liu Subject: [PATCH bpf-next v4 6/6] x86: use register_text_tail_vm Date: Thu, 17 Nov 2022 12:23:22 -0800 Message-ID: <20221117202322.944661-7-song@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20221117202322.944661-1-song@kernel.org> References: <20221117202322.944661-1-song@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8BIT X-FB-Internal: Safe Content-Type: text/plain X-Proofpoint-GUID: 9HuRzM3BweLAlClb-ti3d2LQRnjjvXm1 X-Proofpoint-ORIG-GUID: 9HuRzM3BweLAlClb-ti3d2LQRnjjvXm1 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.219,Aquarius:18.0.895,Hydra:6.0.545,FMLib:17.11.122.1 definitions=2022-11-17_06,2022-11-17_01,2022-06-22_01 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Allocate 2MB pages up to round_up(_etext, 2MB), and register memory [round_up(_etext, 4kb), round_up(_etext, 2MB)] with register_text_tail_vm so that we can use this part of memory for dynamic kernel text (BPF programs, etc.). Here is an example: [root@eth50-1 ~]# grep _etext /proc/kallsyms ffffffff82202a08 T _etext [root@eth50-1 ~]# grep bpf_prog_ /proc/kallsyms | tail -n 3 ffffffff8220f920 t bpf_prog_cc61a5364ac11d93_handle__sched_wakeup [bpf] ffffffff8220fa28 t bpf_prog_cc61a5364ac11d93_handle__sched_wakeup_new [bpf] ffffffff8220fad4 t bpf_prog_3bf73fa16f5e3d92_handle__sched_switch [bpf] [root@eth50-1 ~]# grep 0xffffffff82200000 /sys/kernel/debug/page_tables/kernel 0xffffffff82200000-0xffffffff82400000 2M ro PSE x pmd ffffffff82200000-ffffffff82400000 is a 2MB page, serving kernel text, and bpf programs. Also update Documentation/x86/x86_64/mm.rst to show execmem can be mapped to kernel text addresses. Signed-off-by: Song Liu --- Documentation/x86/x86_64/mm.rst | 4 ++-- arch/x86/include/asm/pgtable_64_types.h | 1 + arch/x86/mm/init_64.c | 4 +++- 3 files changed, 6 insertions(+), 3 deletions(-) diff --git a/Documentation/x86/x86_64/mm.rst b/Documentation/x86/x86_64/mm.rst index 9798676bb0bf..6ee95e5fa7e9 100644 --- a/Documentation/x86/x86_64/mm.rst +++ b/Documentation/x86/x86_64/mm.rst @@ -62,7 +62,7 @@ Complete virtual memory map with 4-level page tables ffffff8000000000 | -512 GB | ffffffeeffffffff | 444 GB | ... unused hole ffffffef00000000 | -68 GB | fffffffeffffffff | 64 GB | EFI region mapping space ffffffff00000000 | -4 GB | ffffffff7fffffff | 2 GB | ... unused hole - ffffffff80000000 | -2 GB | ffffffff9fffffff | 512 MB | kernel text mapping, mapped to physical address 0 + ffffffff80000000 | -2 GB | ffffffff9fffffff | 512 MB | kernel text mapping and execmem, mapped to physical address 0 ffffffff80000000 |-2048 MB | | | ffffffffa0000000 |-1536 MB | fffffffffeffffff | 1520 MB | module mapping space ffffffffff000000 | -16 MB | | | @@ -121,7 +121,7 @@ Complete virtual memory map with 5-level page tables ffffff8000000000 | -512 GB | ffffffeeffffffff | 444 GB | ... unused hole ffffffef00000000 | -68 GB | fffffffeffffffff | 64 GB | EFI region mapping space ffffffff00000000 | -4 GB | ffffffff7fffffff | 2 GB | ... unused hole - ffffffff80000000 | -2 GB | ffffffff9fffffff | 512 MB | kernel text mapping, mapped to physical address 0 + ffffffff80000000 | -2 GB | ffffffff9fffffff | 512 MB | kernel text mapping and execmem, mapped to physical address 0 ffffffff80000000 |-2048 MB | | | ffffffffa0000000 |-1536 MB | fffffffffeffffff | 1520 MB | module mapping space ffffffffff000000 | -16 MB | | | diff --git a/arch/x86/include/asm/pgtable_64_types.h b/arch/x86/include/asm/pgtable_64_types.h index 04f36063ad54..c0f9cceb109a 100644 --- a/arch/x86/include/asm/pgtable_64_types.h +++ b/arch/x86/include/asm/pgtable_64_types.h @@ -101,6 +101,7 @@ extern unsigned int ptrs_per_p4d; #define PUD_MASK (~(PUD_SIZE - 1)) #define PGDIR_SIZE (_AC(1, UL) << PGDIR_SHIFT) #define PGDIR_MASK (~(PGDIR_SIZE - 1)) +#define PMD_ALIGN(x) (((unsigned long)(x) + (PMD_SIZE - 1)) & PMD_MASK) /* * See Documentation/x86/x86_64/mm.rst for a description of the memory map. diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index 3f040c6e5d13..5b42fc0c6099 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -1373,7 +1373,7 @@ void mark_rodata_ro(void) unsigned long start = PFN_ALIGN(_text); unsigned long rodata_start = PFN_ALIGN(__start_rodata); unsigned long end = (unsigned long)__end_rodata_hpage_align; - unsigned long text_end = PFN_ALIGN(_etext); + unsigned long text_end = PMD_ALIGN(_etext); unsigned long rodata_end = PFN_ALIGN(__end_rodata); unsigned long all_end; @@ -1414,6 +1414,8 @@ void mark_rodata_ro(void) (void *)rodata_end, (void *)_sdata); debug_checkwx(); + register_text_tail_vm(PFN_ALIGN((unsigned long)_etext), + PMD_ALIGN((unsigned long)_etext)); } int kern_addr_valid(unsigned long addr) -- 2.30.2