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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 77376C433FE for ; Tue, 16 Nov 2021 05:58:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 582B960F22 for ; Tue, 16 Nov 2021 05:58:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240362AbhKPGBu (ORCPT ); Tue, 16 Nov 2021 01:01:50 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35388 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240161AbhKPGBm (ORCPT ); Tue, 16 Nov 2021 01:01:42 -0500 Received: from mail-pl1-x642.google.com (mail-pl1-x642.google.com [IPv6:2607:f8b0:4864:20::642]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 64953C061231; Mon, 15 Nov 2021 21:42:46 -0800 (PST) Received: by mail-pl1-x642.google.com with SMTP id m24so6464471pls.10; Mon, 15 Nov 2021 21:42:46 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=u0lClWPrvD/K1h3LgglE1rPein98w8QPLX7xeqet6rg=; b=nIqUjdyXfJIJlTHhj+Wzyv5kOeWFHiXSJZu1cjHSdZG33TPnsO5MB5aE1C4JRgbtaA mmhKCAE2v4vfeZS8dZyaB3lwRc023VndgcC/ExPox3+4v3mjg8dHhbARHl1NYWFYfOY3 JkBfc1Yk/ZgIMZocQUQnP+XsrCr3KO1PZKwp1j6PrDgRO2dDh3zhcwJoTZwI5uNBK/MH xgxszz7O26rszx8vfFXErmfnomFI0sDoPR8U+EEv43b+mccAYfqTuEqPJknnqKqUotO3 yPdZqUlX1lOc0cf5SPZjgTYVd0TWGOHfMYtu4YCIJG56ntaOU6JFOt44q69q7Y3kAB7I 73qg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=u0lClWPrvD/K1h3LgglE1rPein98w8QPLX7xeqet6rg=; b=A5MSi2YKDzd8AjitE2dJKq+G1l2y3zeFE2p8rzjrDs6DmktTjl9UikjKzZp/5EGNO7 o5gQYLL6Aq4SxcI6DH7PbH5EhvHnWqLb8HmoXbP6lPBbbDWbkUjZ65rJsZo2Z7u26Ym5 Nn67jenQ1ReJ5gy4rwgiuFjfAXgPiKyT2+a1gUHa3hw8sgC303hgn/ITLqVKX6rmL1iT h5cpmq2FBS64GOzGGB68NNEU/rEcJWTuTiYSuibKUvq4495JaTUdeliV5PO0sZF6HS33 bBv1A3OC3PBlb+lIPmhS6Xzc1zz/276b9pUQMxb6cxCQdZgT2AYF3uEhfC1c4bIZBCyB 1gkQ== X-Gm-Message-State: AOAM530DMoPu42PQVM7VC0HU2xXhRnk0sGJshVqjLz4xynjFSBkqoFKD 405zlVmGP60ANXx8Nq9EnbDIjn7FmVw= X-Google-Smtp-Source: ABdhPJxBGz/SRjgi7l0L6Q8eXVANhWP0NXj0Z57F/L2e+Rs3ReTGP+o5KTksilGOD6ZaEh1ojs4kUg== X-Received: by 2002:a17:90a:4b47:: with SMTP id o7mr35592429pjl.92.1637041365620; Mon, 15 Nov 2021 21:42:45 -0800 (PST) Received: from localhost ([2405:201:6014:d064:3d4e:6265:800c:dc84]) by smtp.gmail.com with ESMTPSA id ne22sm1002573pjb.18.2021.11.15.21.42.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 15 Nov 2021 21:42:45 -0800 (PST) From: Kumar Kartikeya Dwivedi To: bpf@vger.kernel.org Cc: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Pavel Emelyanov , Alexander Mihalicyn , Andrei Vagin , criu@openvz.org, io-uring@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: [PATCH bpf-next v1 2/8] bpf: Add bpf_page_to_pfn helper Date: Tue, 16 Nov 2021 11:12:31 +0530 Message-Id: <20211116054237.100814-3-memxor@gmail.com> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20211116054237.100814-1-memxor@gmail.com> References: <20211116054237.100814-1-memxor@gmail.com> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=5296; h=from:subject; bh=vnwFxGdaJpBG++VBChgGlEBqIAnV9UjRswVX4pSbVSY=; b=owEBbQKS/ZANAwAIAUzgyIZIvxHKAcsmYgBhk0S6qXxy7qrRuQKRRKAIPrBzMZcEaYxS3VShsUn5 OQUSrtCJAjMEAAEIAB0WIQRLvip+Buz51YI8YRFM4MiGSL8RygUCYZNEugAKCRBM4MiGSL8RyhmCEA CscqOFYalotS2DTRoBPvy+r8xLyKJ9AzMEnwRUfcK8OrSzIJn1n8mjRyGwBLnkShbC94pmq54fcxXx 0WJDgl0PUrIhxw2FIDbSOTI+RciU1hO9DSY6cH0dCa5JF6WpDBim2rDb+4UUs2tR9f0TOGKTUvummc DBBLKcgdrMbBh4fedbPK5UgB8elzM+BNFyvOgrkOfCBiiUjI312Y0qrM8TxK9XJjrsGQp90KTPwMP8 C2eg2HRa0yhmTwpCXqJWAYTz2yAPWyM/EYhV1nZfTqFM0zcc/CIqCjwJtV0d7Ccj1UzxIGa3lq9HoP q0X2aQPvQOO29lW/t+yf0sRsNE+VKqGkUAcAQAtdfQ3oL2+IUXmYT3LfArA4zrv30TpRX+M0sJXCOi v3L2MWELIX6XB00e+waSAi9dN1WU02dCILGZBpkQJm3Q70XrZRHSmT5DlXEc6ZaV5lcpySztIE9A7G mgc1FVeMk+mEVmTSRgiUtDJ5RhR8tEeN9YCwFqA8VYCUq0wA4Uort0i/mWa2KZmQOt7UJwjB8LsgH8 pFioVZsNj3J8uDiFf8LtR5F4nISevNB3Jn3/fR3DvLgmOQrnbOOFqNib6tlrNuuhUN1h5Mtig38IiB MgQLSNT6evdzBFcBY4rEsGQ+UcpQ2ZMocvXot1b0sszN4WPKQsr3NUPzryIA== X-Developer-Key: i=memxor@gmail.com; a=openpgp; fpr=4BBE2A7E06ECF9D5823C61114CE0C88648BF11CA Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org In CRIU, we need to be able to determine whether the page pinned by io_uring is still present in the same range in the process VMA. /proc//pagemap gives us the PFN, hence using this helper we can establish this mapping easily from the iterator side. It is a simple wrapper over the in-kernel page_to_pfn helper, and ensures the passed in pointer is a struct page PTR_TO_BTF_ID. This is obtained from the bvec of io_uring_ubuf for the CRIU usecase. Signed-off-by: Kumar Kartikeya Dwivedi --- fs/io_uring.c | 17 +++++++++++++++++ include/linux/bpf.h | 1 + include/uapi/linux/bpf.h | 9 +++++++++ kernel/trace/bpf_trace.c | 2 ++ scripts/bpf_doc.py | 2 ++ tools/include/uapi/linux/bpf.h | 9 +++++++++ 6 files changed, 40 insertions(+) diff --git a/fs/io_uring.c b/fs/io_uring.c index 46a110989155..9e9df6767e29 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -11295,6 +11295,23 @@ static struct bpf_iter_reg io_uring_buf_reg_info = { .seq_info = &bpf_io_uring_buf_seq_info, }; +BPF_CALL_1(bpf_page_to_pfn, struct page *, page) +{ + /* PTR_TO_BTF_ID can be NULL */ + if (!page) + return U64_MAX; + return page_to_pfn(page); +} + +BTF_ID_LIST_SINGLE(btf_page_to_pfn_ids, struct, page) + +const struct bpf_func_proto bpf_page_to_pfn_proto = { + .func = bpf_page_to_pfn, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_BTF_ID, + .arg1_btf_id = &btf_page_to_pfn_ids[0], +}; + static int __init io_uring_iter_init(void) { io_uring_buf_reg_info.ctx_arg_info[0].btf_id = btf_io_uring_ids[0]; diff --git a/include/linux/bpf.h b/include/linux/bpf.h index ddb9d4520a3f..fe7b499da781 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -2166,6 +2166,7 @@ extern const struct bpf_func_proto bpf_sk_setsockopt_proto; extern const struct bpf_func_proto bpf_sk_getsockopt_proto; extern const struct bpf_func_proto bpf_kallsyms_lookup_name_proto; extern const struct bpf_func_proto bpf_find_vma_proto; +extern const struct bpf_func_proto bpf_page_to_pfn_proto; const struct bpf_func_proto *tracing_prog_func_proto( enum bpf_func_id func_id, const struct bpf_prog *prog); diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 3323defa99a1..b70e9da3d722 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -4960,6 +4960,14 @@ union bpf_attr { * **-ENOENT** if *task->mm* is NULL, or no vma contains *addr*. * **-EBUSY** if failed to try lock mmap_lock. * **-EINVAL** for invalid **flags**. + * + * long bpf_page_to_pfn(struct page *page) + * Description + * Obtain the page frame number (PFN) for the given *struct page* + * pointer. + * Return + * Page Frame Number corresponding to the page pointed to by the + * *struct page* pointer, or U64_MAX if pointer is NULL. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -5143,6 +5151,7 @@ union bpf_attr { FN(skc_to_unix_sock), \ FN(kallsyms_lookup_name), \ FN(find_vma), \ + FN(page_to_pfn), \ /* */ /* integer value in 'imm' field of BPF_CALL instruction selects which helper diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 25ea521fb8f1..f68a8433be1a 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -1212,6 +1212,8 @@ bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_find_vma_proto; case BPF_FUNC_trace_vprintk: return bpf_get_trace_vprintk_proto(); + case BPF_FUNC_page_to_pfn: + return &bpf_page_to_pfn_proto; default: return bpf_base_func_proto(func_id); } diff --git a/scripts/bpf_doc.py b/scripts/bpf_doc.py index a6403ddf5de7..ae68ca794980 100755 --- a/scripts/bpf_doc.py +++ b/scripts/bpf_doc.py @@ -549,6 +549,7 @@ class PrinterHelpers(Printer): 'struct socket', 'struct file', 'struct bpf_timer', + 'struct page', ] known_types = { '...', @@ -598,6 +599,7 @@ class PrinterHelpers(Printer): 'struct socket', 'struct file', 'struct bpf_timer', + 'struct page', } mapped_types = { 'u8': '__u8', diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 3323defa99a1..b70e9da3d722 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -4960,6 +4960,14 @@ union bpf_attr { * **-ENOENT** if *task->mm* is NULL, or no vma contains *addr*. * **-EBUSY** if failed to try lock mmap_lock. * **-EINVAL** for invalid **flags**. + * + * long bpf_page_to_pfn(struct page *page) + * Description + * Obtain the page frame number (PFN) for the given *struct page* + * pointer. + * Return + * Page Frame Number corresponding to the page pointed to by the + * *struct page* pointer, or U64_MAX if pointer is NULL. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -5143,6 +5151,7 @@ union bpf_attr { FN(skc_to_unix_sock), \ FN(kallsyms_lookup_name), \ FN(find_vma), \ + FN(page_to_pfn), \ /* */ /* integer value in 'imm' field of BPF_CALL instruction selects which helper -- 2.33.1