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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id B107EC369C2 for ; Wed, 23 Apr 2025 01:49:38 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id EC5116B0005; Tue, 22 Apr 2025 21:49:36 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id E76386B0007; Tue, 22 Apr 2025 21:49:36 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D639C6B0008; Tue, 22 Apr 2025 21:49:36 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id B62F96B0005 for ; Tue, 22 Apr 2025 21:49:36 -0400 (EDT) Received: from smtpin16.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 9E06180424 for ; Wed, 23 Apr 2025 01:49:37 +0000 (UTC) X-FDA: 83363626794.16.9DBCB51 Received: from out-185.mta0.migadu.com (out-185.mta0.migadu.com [91.218.175.185]) by imf03.hostedemail.com (Postfix) with ESMTP id E159F20006 for ; Wed, 23 Apr 2025 01:49:35 +0000 (UTC) Authentication-Results: imf03.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=hDIfCpjq; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf03.hostedemail.com: domain of ye.liu@linux.dev designates 91.218.175.185 as permitted sender) smtp.mailfrom=ye.liu@linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1745372976; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:references:dkim-signature; bh=D7+Eeawz4Y8be/9ifCJRuEJtqE9u4PyZ//yEy9tp5gM=; b=48vKO9tf2QuHlkm6hZFnhy6Q3joleeyfdvi5ptP/Fi5t7DoNKQHP6GpSVgVKazq2exHxtF vEXV24pPartSDUW8nHLPo7jT6gc7ll1qkEUZmbFkeyxQNHvqK8xTVHxe2M8Rr5oGpTYWoj Ayd8BLNRMQ4rTQIykY2YKJEszCXuna8= ARC-Authentication-Results: i=1; imf03.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=hDIfCpjq; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf03.hostedemail.com: domain of ye.liu@linux.dev designates 91.218.175.185 as permitted sender) smtp.mailfrom=ye.liu@linux.dev ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1745372976; a=rsa-sha256; cv=none; b=FleNmVzPQp4HQ33SyJxRuXoDtrbGFwuuPtyzDNHHPg5T4kOSR7Dsin1T4dC3e9kpa9otGK JoQGsdvRJ8fS3eoQ35NpnGX9FfWst0h1Xota/UHc8A2nM0MKZCyCt0l5wHQvcuguHFOU6h Sx/zcT1PMOsVGU/+5gL4UtXVulSdGHQ= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1745372973; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=D7+Eeawz4Y8be/9ifCJRuEJtqE9u4PyZ//yEy9tp5gM=; b=hDIfCpjquE1JLYG/4MpX+xVTGu9k+j4qthA+S/jS9mLcZMNR6fspBEDZeuI/O4zCMlPkyP Z5qhwNtkHDuUCJWpPusNB6X5SoGfoJUSXafQalpX/21JzuyG/OqZiVm9yU14C8anogzOJ1 wJ9xXiQb+ouXbvv5z7MY0YlzBQwDU9Y= From: Ye Liu To: akpm@linux-foundation.org Cc: linux-debuggers@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-toolchains@vger.kernel.org, osandov@osandov.com, paulmck@kernel.org, sweettea-kernel@dorminy.me, liuye@kylinos.cn, ye.liu@linux.dev Subject: [PATCH v3] tools/mm: Add script to display page state for a given PID and VADDR Date: Wed, 23 Apr 2025 09:48:50 +0800 Message-Id: <20250423014850.344501-1-ye.liu@linux.dev> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT X-Stat-Signature: 4ak9hac5px5z75r5pizeod5xetadw6e9 X-Rspamd-Queue-Id: E159F20006 X-Rspam-User: X-Rspamd-Server: rspam05 X-HE-Tag: 1745372975-933214 X-HE-Meta: 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 VX5sZkRF YRzBZdkgGvEMY4FbCNQ62Joh2cSnlFaTLRVsvqVW831imGDtfEc9ke1E5POxN4cVc2PiTPI7p3FwFbm8BAjkx6IK/9i4QtBeqAGC87cXneYN1TCl1qEQ8SRw39muOaK1vmq1NWcPED9gT9s0TAe5ikd5oW0Zpy5lCY/C9QSP9yQjigyTmC+Nhmo8veXQC1MvHTt9CNbXxngEu7r/WPOp3fsgQpnQ9972L0OcCZG7qrEc2Ss08eHsLFVWYrw== 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: List-Subscribe: List-Unsubscribe: From: Ye Liu Introduces a new drgn script, `show_page_info.py`, which allows users to analyze the state of a page given a process ID (PID) and a virtual address (VADDR). This can help kernel developers or debuggers easily inspect page-related information in a live kernel or vmcore. The script extracts information such as the page flags, mapping, and other metadata relevant to diagnosing memory issues. Output example: sudo ./show_page_info.py 1 0x7f43df5acf00 PID: 1 Comm: systemd mm: 0xffff8881273bbc40 Raw: 0017ffffc000416c ffffea00043a4508 ffffea0004381e08 ffff88810f086a70 Raw: 0000000000000000 ffff888120c9b0c0 0000002500000007 ffff88812642c000 User Virtual Address: 0x7f43df5acf00 Page Address: 0xffffea00049a0b00 Page Flags: PG_referenced|PG_uptodate|PG_lru|PG_head|PG_active| PG_private|PG_reported Page Size: 16384 Page PFN: 0x12682c Page Physical: 0x12682c000 Page Virtual: 0xffff88812682c000 Page Refcount: 37 Page Mapcount: 7 Page Index: 0x0 Page Memcg Data: 0xffff88812642c000 Memcg Name: init.scope Memcg Path: /sys/fs/cgroup/memory/init.scope Page Mapping: 0xffff88810f086a70 Page Anon/File: File Page VMA: 0xffff88810e4af3b8 VMA Start: 0x7f43df5ac000 VMA End: 0x7f43df5b0000 This page is part of a compound page. This page is the head page of a compound page. Head Page: 0xffffea00049a0b00 Compound Order: 2 Number of Pages: 4 Signed-off-by: Ye Liu Changes in v3: - Adjust display style. - Link to v2:https://lore.kernel.org/all/20250421080748.114750-1-ye.liu@linux.dev/ Changes in v2: - Move the show_page_info.py file to tools/mm. - Link to v1: https://lore.kernel.org/all/20250415075024.248232-1-ye.liu@linux.dev/ --- MAINTAINERS | 5 ++ tools/mm/show_page_info.py | 120 +++++++++++++++++++++++++++++++++++++ 2 files changed, 125 insertions(+) create mode 100755 tools/mm/show_page_info.py diff --git a/MAINTAINERS b/MAINTAINERS index 17ed0b5ffdd2..85686a30dc72 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -18351,6 +18351,11 @@ F: Documentation/mm/page_table_check.rst F: include/linux/page_table_check.h F: mm/page_table_check.c +PAGE STATE DEBUG SCRIPT +M: Ye Liu +S: Maintained +F: tools/mm/show_page_info.py + PANASONIC LAPTOP ACPI EXTRAS DRIVER M: Kenneth Chan L: platform-driver-x86@vger.kernel.org diff --git a/tools/mm/show_page_info.py b/tools/mm/show_page_info.py new file mode 100755 index 000000000000..8622c5499dfe --- /dev/null +++ b/tools/mm/show_page_info.py @@ -0,0 +1,120 @@ +#!/usr/bin/env drgn +# SPDX-License-Identifier: GPL-2.0-only +# Copyright (C) 2025 Ye Liu + +import argparse +from drgn import Object +from drgn.helpers.linux import find_task, follow_page, page_size +from drgn.helpers.linux.mm import ( + decode_page_flags, page_to_pfn, page_to_phys, page_to_virt, vma_find, + PageSlab, PageCompound, PageHead, PageTail, compound_head, compound_order, compound_nr +) +from drgn.helpers.linux.cgroup import cgroup_name, cgroup_path + +DESC = """ +This is a drgn script to show the page state. +For more info on drgn, visit https://github.com/osandov/drgn. +""" + +MEMCG_DATA_OBJEXTS = 1 << 0 +MEMCG_DATA_KMEM = 1 << 1 +__NR_MEMCG_DATA_FLAGS = 1 << 2 + +def format_page_data(data): + """Format raw page data into a readable hex dump.""" + chunks = [data[i:i+8] for i in range(0, len(data), 8)] + hex_chunks = ["".join(f"{b:02x}" for b in chunk[::-1]) for chunk in chunks] + lines = [" ".join(hex_chunks[i:i+4]) for i in range(0, len(hex_chunks), 4)] + return "\n".join(f"Raw: {line}" for line in lines) + +def get_memcg_info(page): + """Retrieve memory cgroup information for a page.""" + memcg_data = page.memcg_data.value_() + if memcg_data & MEMCG_DATA_OBJEXTS: + memcg_value = 0 + elif memcg_data & MEMCG_DATA_KMEM: + objcg = Object(prog, "struct obj_cgroup *", address=memcg_data & ~__NR_MEMCG_DATA_FLAGS) + memcg_value = objcg.memcg.value_() + else: + memcg_value = memcg_data & ~__NR_MEMCG_DATA_FLAGS + + memcg = Object(prog, "struct mem_cgroup *", address=memcg_value) + cgrp = memcg.css.cgroup + return cgroup_name(cgrp).decode(), f"/sys/fs/cgroup/memory{cgroup_path(cgrp).decode()}" + +def show_page_state(page, addr, mm, pid, task): + """Display detailed information about a page.""" + print(f'PID: {pid} Comm: {task.comm.string_().decode()} mm: {hex(mm)}') + print(format_page_data(prog.read(page.value_(), 64))) + fields = { + "User Virtual Address": hex(addr), + "Page Address": hex(page.value_()), + "Page Flags": decode_page_flags(page), + "Page Size": page_size(page).value_(), + "Page PFN": hex(page_to_pfn(page).value_()), + "Page Physical": hex(page_to_phys(page).value_()), + "Page Virtual": hex(page_to_virt(page).value_()), + "Page Refcount": page._refcount.counter.value_(), + "Page Mapcount": page._mapcount.counter.value_(), + "Page Index": hex(page.index.value_()), + "Page Memcg Data": hex(page.memcg_data.value_()), + } + + memcg_name, memcg_path = get_memcg_info(page) + fields["Memcg Name"] = memcg_name + fields["Memcg Path"] = memcg_path + fields["Page Mapping"] = hex(page.mapping.value_()) + fields["Page Anon/File"] = "Anon" if page.mapping.value_() & 0x1 else "File" + + vma = vma_find(mm, addr) + fields["Page VMA"] = hex(vma.value_()) + fields["VMA Start"] = hex(vma.vm_start.value_()) + fields["VMA End"] = hex(vma.vm_end.value_()) + + # Calculate the maximum field name length for alignment + max_field_len = max(len(field) for field in fields) + + # Print aligned fields + for field, value in fields.items(): + print(f"{field}:".ljust(max_field_len + 2) + f"{value}") + + # Additional information about the page + if PageSlab(page): + print("This page belongs to the slab allocator.") + + if PageCompound(page): + print("This page is part of a compound page.") + if PageHead(page): + print("This page is the head page of a compound page.") + if PageTail(page): + print("This page is the tail page of a compound page.") + print(f"{'Head Page:'.ljust(max_field_len + 2)}{hex(compound_head(page).value_())}") + print(f"{'Compound Order:'.ljust(max_field_len + 2)}{compound_order(page).value_()}") + print(f"{'Number of Pages:'.ljust(max_field_len + 2)}{compound_nr(page).value_()}") + else: + print("This page is not part of a compound page.") + +def main(): + """Main function to parse arguments and display page state.""" + parser = argparse.ArgumentParser(description=DESC, formatter_class=argparse.RawTextHelpFormatter) + parser.add_argument('pid', metavar='PID', type=int, help='Target process ID (PID)') + parser.add_argument('vaddr', metavar='VADDR', type=str, help='Target virtual address in hexadecimal format (e.g., 0x7fff1234abcd)') + args = parser.parse_args() + + try: + vaddr = int(args.vaddr, 16) + except ValueError: + print(f"Error: Invalid virtual address format: {args.vaddr}") + return + + task = find_task(args.pid) + mm = task.mm + page = follow_page(mm, vaddr) + + if page: + show_page_state(page, vaddr, mm, args.pid, task) + else: + print(f"Address {hex(vaddr)} is not mapped.") + +if __name__ == "__main__": + main() \ No newline at end of file -- 2.25.1