From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 393582AD2F; Wed, 23 Apr 2025 22:00:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745445621; cv=none; b=M4Zkfcm1H6xMEfKUzz7sP552DK+hkl8sugU6IyhqMdwoC34UIfkyQEpKgwRC1uY4HjYFKTMH9i2ddpKZO5kfgVKmQJq85I9+5AvS/TK8eqaQN3ubzuNTKj5WKpKRBJKGpGwt5L2LlmIKbS5/iSOj8v815Gj9DllOK9bl/P0hKig= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745445621; c=relaxed/simple; bh=xld+VoV53U8iJEngkFS9wdEIMdzNHJgri52xFjZ3HQ0=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=PgURf7NLch5fofTMmTd6Pj7spTU4/D5dQPXnV7bK9grOMcu3BQVJSUf7TTc+R6gpbDEzgeUAvMUZupBzOMfez+lkmjUadgFlJ58khgmL+sPAQkvqDGoscDFqaK1GC98RdEDja+UmzcEzxum1kShpa3tNIeF/HpWjotJXu7VpMMw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=vLrPW9ai; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="vLrPW9ai" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E09FEC4CEE2; Wed, 23 Apr 2025 22:00:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1745445621; bh=xld+VoV53U8iJEngkFS9wdEIMdzNHJgri52xFjZ3HQ0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vLrPW9aitySK4LgFfX0+RXjm26Jmxh+5O2meoV4ozpE8mz6M6rr1HQHJ52/Ho4XLg KHAJNOsqigFLF0xzq7BEH/1PCQ+uzt1Un/LblgGltmbXWVG6NgHWeAEGoJJ4XneJpU JEo/c2r2WsK8/B9RiDUxhHBXCw+CqsOEwUfZZ7/2ux2sDwGG1VuC1NzWVjVoTAwTuZ 6EORJy0ld139oY8LS12i8nB36Ht2igPgv2Cf65nJdkYdwgBPBN+iaCSBd7dw8dZuXC AnjIb485TkknSOONevxhrCmSbppxemmS3mAExQOrzVZDRijm2ApQ+pP5lB1eG9rK5n HRF58FkLfvP6g== From: SeongJae Park To: Ye Liu Cc: SeongJae Park , akpm@linux-foundation.org, 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 Subject: Re: [PATCH v3] tools/mm: Add script to display page state for a given PID and VADDR Date: Wed, 23 Apr 2025 15:00:18 -0700 Message-Id: <20250423220018.45789-1-sj@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250423014850.344501-1-ye.liu@linux.dev> References: Precedence: bulk X-Mailing-List: linux-toolchains@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit On Wed, 23 Apr 2025 09:48:50 +0800 Ye Liu wrote: > 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 Should this be called folio size? Or, could this simply removed since Compound Order is given below? > 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 [...] > +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) I tried this script on my test machine and got the below error: $ cat ./a.c #include int main(void) { int foo; printf("hello\n"); printf("%x\n", &foo); scanf("%d\n", &foo); return 0; } $ gcc ./a.c $ ./a.out & [2] 45666 hello f7eb7c0c $ sudo ./tools/mm/show_page_info.py 45666 0xf7eb7c0c Traceback (most recent call last): File "/usr/local/bin/drgn", line 33, in sys.exit(load_entry_point('drgn==0.0.30+82.ge2b60e4b', 'console_scripts', 'drgn')()) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/usr/local/lib/python3.11/dist-packages/drgn-0.0.30+82.ge2b60e4b-py3.11-linux-x86_64.egg/drgn/cli.py", line 461, in _main runpy.run_path(script, init_globals={"prog": prog}, run_name="__main__") File "", line 291, in run_path File "", line 98, in _run_module_code File "", line 88, in _run_code File "./tools/mm/show_page_info.py", line 120, in main() File "./tools/mm/show_page_info.py", line 112, in main page = follow_page(mm, vaddr) ^^^^^^^^^^^^^^^^^^^^^^ File "/usr/local/lib/python3.11/dist-packages/drgn-0.0.30+82.ge2b60e4b-py3.11-linux-x86_64.egg/drgn/helpers/linux/mm.py", line 1068, in follow_page return phys_to_page(follow_phys(mm, addr)) ^^^^^^^^^^^^^^^^^^^^^ File "/usr/local/lib/python3.11/dist-packages/drgn-0.0.30+82.ge2b60e4b-py3.11-linux-x86_64.egg/drgn/helpers/linux/mm.py", line 1109, in follow_phys return Object(prog, "phys_addr_t", _linux_helper_follow_phys(prog, mm.pgd, addr)) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ _drgn.FaultError: address is not mapped: 0xf7eb7c0c Am I doing something wrong? Thanks, SJ [...]