From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Knut Omang <knut.omang@oracle.com>
Cc: linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-doc@vger.kernel.org, linux-kbuild@vger.kernel.org,
Shuah Khan <shuah@kernel.org>, Jonathan Corbet <corbet@lwn.net>,
Masahiro Yamada <yamada.masahiro@socionext.com>,
Michal Marek <michal.lkml@markovi.net>,
Shreyans Devendra Doshi <0xinfosect0r@gmail.com>,
Alan Maguire <alan.maguire@oracle.com>,
Brendan Higgins <brendanhiggins@google.com>,
Kevin Hilman <khilman@baylibre.com>,
Hidenori Yamaji <hidenori.yamaji@sony.com>,
Frank Rowand <frowand.list@gmail.com>,
Timothy Bird <Tim.Bird@sony.com>,
Luis Chamberlain <mcgrof@kernel.org>,
Theodore Ts'o <tytso@mit.edu>, Daniel Vetter <daniel@ffwll.ch>,
Stephen Boyd <sboyd@kernel.org>
Subject: Re: [RFC 06/19] ktf: A simple debugfs interface to test results
Date: Tue, 13 Aug 2019 10:21:52 +0200 [thread overview]
Message-ID: <20190813082152.GA17627@kroah.com> (raw)
In-Reply-To: <ae6c38384e2338aa3cfb8a4e4dd1002833789253.1565676440.git-series.knut.omang@oracle.com>
On Tue, Aug 13, 2019 at 08:09:21AM +0200, Knut Omang wrote:
> From: Alan Maguire <alan.maguire@oracle.com>
>
> While test results is available via netlink from user space, sometimes
> it may be useful to be able to access the results from the kernel as well,
> for instance due to a crash. Make that possible via debugfs.
>
> ktf_debugfs.h: Support for creating a debugfs representation of test
>
> Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
> Signed-off-by: Knut Omang <knut.omang@oracle.com>
> ---
> tools/testing/selftests/ktf/kernel/ktf_debugfs.c | 356 ++++++++++++++++-
> tools/testing/selftests/ktf/kernel/ktf_debugfs.h | 34 ++-
> 2 files changed, 390 insertions(+)
> create mode 100644 tools/testing/selftests/ktf/kernel/ktf_debugfs.c
> create mode 100644 tools/testing/selftests/ktf/kernel/ktf_debugfs.h
>
> diff --git a/tools/testing/selftests/ktf/kernel/ktf_debugfs.c b/tools/testing/selftests/ktf/kernel/ktf_debugfs.c
> new file mode 100644
> index 0000000..a20fbd2
> --- /dev/null
> +++ b/tools/testing/selftests/ktf/kernel/ktf_debugfs.c
> @@ -0,0 +1,356 @@
> +/*
> + * Copyright (c) 2009, 2017, Oracle and/or its affiliates. All rights reserved.
> + * Author: Alan Maguire <alan.maguire@oracle.com>
> + *
> + * SPDX-License-Identifier: GPL-2.0
Has to be the first line of the file, did you run this through
checkpatch?
> +static int ktf_run_test_open(struct inode *inode, struct file *file)
> +{
> + struct ktf_test *t;
> +
> + if (!try_module_get(THIS_MODULE))
> + return -EIO;
This is an anti-pattern, and one guaranteed to not work properly. NEVER
do this.
> +
> + t = (struct ktf_test *)inode->i_private;
> +
> + return single_open(file, ktf_debugfs_run, t);
> +}
> +
> +static int ktf_debugfs_release(struct inode *inode, struct file *file)
> +{
> + module_put(THIS_MODULE);
Same here, not ok.
> + return single_release(inode, file);
> +}
> +
> +static const struct file_operations ktf_run_test_fops = {
> + .open = ktf_run_test_open,
> + .read = seq_read,
> + .llseek = seq_lseek,
> + .release = ktf_debugfs_release,
> +};
> +
> +static int ktf_results_test_open(struct inode *inode, struct file *file)
> +{
> + struct ktf_test *t;
> +
> + if (!try_module_get(THIS_MODULE))
> + return -EIO;
Nope!
And why -EIO? That is not an io issue.
> +void ktf_debugfs_create_test(struct ktf_test *t)
> +{
> + struct ktf_case *testset = ktf_case_find(t->tclass);
> +
> + if (!testset)
> + return;
> +
> + memset(&t->debugfs, 0, sizeof(t->debugfs));
> +
> + t->debugfs.debugfs_results_test =
> + debugfs_create_file(t->name, S_IFREG | 0444,
> + testset->debugfs.debugfs_results_test,
> + t, &ktf_results_test_fops);
> +
> + if (t->debugfs.debugfs_results_test) {
How can that variable ever be NULL (hint, it can not.)
> + t->debugfs.debugfs_run_test =
> + debugfs_create_file(t->name, S_IFREG | 0444,
> + testset->debugfs.debugfs_run_test,
> + t, &ktf_run_test_fops);
> + if (!t->debugfs.debugfs_run_test) {
> + _ktf_debugfs_destroy_test(t);
> + } else {
> + /* Take reference for test for debugfs */
> + ktf_test_get(t);
> + }
> + }
Never test the result of any debugfs call, you do not need to. Just
call it and move on, your code flow should NEVER be different with, or
without, a successful debugfs call.
> +static int ktf_run_testset_open(struct inode *inode, struct file *file)
> +{
> + struct ktf_case *testset;
> +
> + if (!try_module_get(THIS_MODULE))
> + return -EIO;
Again no. I hate to know what code you copied this all from, as that
code is very wrong. Do you have a pointer to that code anywhere so we
can fix that up?
> +
> + testset = (struct ktf_case *)inode->i_private;
> +
> + return single_open(file, ktf_debugfs_run_all, testset);
> +}
> +
> +static const struct file_operations ktf_run_testset_fops = {
> + .open = ktf_run_testset_open,
> + .read = seq_read,
> + .llseek = seq_lseek,
> + .release = ktf_debugfs_release,
If you really care about module references you should be setting the
owner of the module here.
> +};
> +
> +static void _ktf_debugfs_destroy_testset(struct ktf_case *testset)
> +{
> + debugfs_remove(testset->debugfs.debugfs_run_testset);
> + debugfs_remove(testset->debugfs.debugfs_run_test);
> + debugfs_remove(testset->debugfs.debugfs_results_testset);
> + debugfs_remove(testset->debugfs.debugfs_results_test);
Why not just recursivly remove the directory? That way you do not have
to keep track of any individual files.
> +}
> +
> +void ktf_debugfs_create_testset(struct ktf_case *testset)
> +{
> + char tests_subdir[KTF_DEBUGFS_NAMESZ];
> + const char *name = ktf_case_name(testset);
> +
> + memset(&testset->debugfs, 0, sizeof(testset->debugfs));
> +
> + /* First add /sys/kernel/debug/ktf/[results|run]/<testset> */
> + testset->debugfs.debugfs_results_testset =
> + debugfs_create_file(name, S_IFREG | 0444,
> + ktf_debugfs_resultsdir,
> + testset, &ktf_results_testset_fops);
> + if (!testset->debugfs.debugfs_results_testset)
> + goto err;
Again, can never happen, and again, do not do different things depending
on the result of a debugfs call.
> +
> + testset->debugfs.debugfs_run_testset =
> + debugfs_create_file(name, S_IFREG | 0444,
> + ktf_debugfs_rundir,
> + testset, &ktf_run_testset_fops);
> + if (!testset->debugfs.debugfs_run_testset)
> + goto err;
Again, nope.
> +
> + /* Now add parent directories for individual test result/run tests
> + * which live in
> + * /sys/kernel/debug/ktf/[results|run]/<testset>-tests/<testname>
> + */
> + (void)snprintf(tests_subdir, sizeof(tests_subdir), "%s%s",
> + name, KTF_DEBUGFS_TESTS_SUFFIX);
why (void)?
> +
> + testset->debugfs.debugfs_results_test =
> + debugfs_create_dir(tests_subdir, ktf_debugfs_resultsdir);
> + if (!testset->debugfs.debugfs_results_test)
> + goto err;
nope :)
> +
> + testset->debugfs.debugfs_run_test =
> + debugfs_create_dir(tests_subdir, ktf_debugfs_rundir);
> + if (!testset->debugfs.debugfs_run_test)
> + goto err;
Nope :)
> +
> + /* Take reference count for testset. One will do as we will always
> + * free testset debugfs resources together.
> + */
> + ktf_case_get(testset);
> + return;
> +err:
> + _ktf_debugfs_destroy_testset(testset);
> +}
> +
> +void ktf_debugfs_destroy_testset(struct ktf_case *testset)
> +{
> + tlog(T_DEBUG, "Destroying debugfs testset %s", ktf_case_name(testset));
> + _ktf_debugfs_destroy_testset(testset);
> + /* Remove our debugfs reference cout to testset */
> + ktf_case_put(testset);
> +}
> +
> +/* /sys/kernel/debug/ktf/coverage shows coverage statistics. */
> +static int ktf_debugfs_cov(struct seq_file *seq, void *v)
> +{
> + ktf_cov_seq_print(seq);
> +
> + return 0;
> +}
> +
> +static int ktf_cov_open(struct inode *inode, struct file *file)
> +{
> + if (!try_module_get(THIS_MODULE))
> + return -EIO;
{sigh} I'll stop reviewing now :)
thanks,
greg k-h
next prev parent reply other threads:[~2019-08-13 8:21 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-13 6:09 [RFC 00/19] Integration of Kernel Test Framework (KTF) into the kernel tree Knut Omang
2019-08-13 6:09 ` [RFC 01/19] kbuild: Fixes to rules for host-cshlib and host-cxxshlib Knut Omang
2019-08-13 14:01 ` Masahiro Yamada
2019-08-13 16:19 ` Knut Omang
2019-08-14 2:02 ` Masahiro Yamada
2019-08-14 5:50 ` Knut Omang
2019-08-14 5:52 ` Knut Omang
2019-08-14 12:52 ` Knut Omang
2019-08-21 1:47 ` Masahiro Yamada
2019-08-21 4:03 ` Knut Omang
2019-08-13 6:09 ` [RFC 02/19] ktf: Introduce the main part of the kernel side of ktf Knut Omang
2019-09-09 1:23 ` Brendan Higgins
2019-09-10 6:15 ` Knut Omang
2019-08-13 6:09 ` [RFC 03/19] ktf: Introduce a generic netlink protocol for test result communication Knut Omang
2019-09-09 1:28 ` Brendan Higgins
2019-09-10 6:30 ` Knut Omang
2019-08-13 6:09 ` [RFC 04/19] ktf: An implementation of a generic associative array container Knut Omang
2019-08-13 6:09 ` [RFC 05/19] ktf: Implementation of ktf support for overriding function entry and return Knut Omang
2019-08-13 6:09 ` [RFC 06/19] ktf: A simple debugfs interface to test results Knut Omang
2019-08-13 8:21 ` Greg Kroah-Hartman [this message]
2019-08-14 17:17 ` Knut Omang
2019-08-15 8:49 ` Greg Kroah-Hartman
2019-08-15 10:35 ` Knut Omang
2019-08-15 10:52 ` Greg Kroah-Hartman
2019-08-13 6:09 ` [RFC 07/19] ktf: Simple coverage support Knut Omang
2019-08-13 6:09 ` [RFC 08/19] ktf: Configurable context support for network info setup Knut Omang
2019-08-13 6:09 ` [RFC 09/19] ktf: resolve: A helper utility to aid in exposing private kernel symbols to KTF tests Knut Omang
2019-08-13 6:09 ` [RFC 10/19] ktf: Add documentation for Kernel Test Framework (KTF) Knut Omang
2019-08-13 6:09 ` [RFC 11/19] ktf: Add a small test suite with a few tests to test KTF itself Knut Omang
2019-08-13 6:09 ` [RFC 12/19] ktf: Main part of user land library for executing tests Knut Omang
2019-08-13 6:09 ` [RFC 13/19] ktf: Integration logic for running ktf tests from googletest Knut Omang
2019-08-13 6:09 ` [RFC 14/19] ktf: Internal debugging facilities Knut Omang
2019-08-13 6:09 ` [RFC 15/19] ktf: Some simple examples Knut Omang
2019-08-13 6:09 ` [RFC 16/19] ktf: Some user applications to run tests Knut Omang
2019-08-13 6:09 ` [RFC 17/19] ktf: Toplevel ktf Makefile/makefile includes and scripts to run from kselftest Knut Omang
2019-08-13 6:09 ` [RFC 18/19] kselftests: Enable building ktf Knut Omang
2019-08-13 6:09 ` [RFC 19/19] Documentation/dev-tools: Add index entry for KTF documentation Knut Omang
2019-08-13 8:10 ` [RFC 00/19] Integration of Kernel Test Framework (KTF) into the kernel tree Brendan Higgins
2019-08-13 8:17 ` Brendan Higgins
2019-08-13 11:29 ` Knut Omang
2019-08-13 17:50 ` Brendan Higgins
2019-08-13 8:23 ` Greg Kroah-Hartman
2019-08-13 9:51 ` Knut Omang
2019-08-13 17:02 ` Brendan Higgins
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190813082152.GA17627@kroah.com \
--to=gregkh@linuxfoundation.org \
--cc=0xinfosect0r@gmail.com \
--cc=Tim.Bird@sony.com \
--cc=alan.maguire@oracle.com \
--cc=brendanhiggins@google.com \
--cc=corbet@lwn.net \
--cc=daniel@ffwll.ch \
--cc=frowand.list@gmail.com \
--cc=hidenori.yamaji@sony.com \
--cc=khilman@baylibre.com \
--cc=knut.omang@oracle.com \
--cc=linux-doc@vger.kernel.org \
--cc=linux-kbuild@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-kselftest@vger.kernel.org \
--cc=mcgrof@kernel.org \
--cc=michal.lkml@markovi.net \
--cc=sboyd@kernel.org \
--cc=shuah@kernel.org \
--cc=tytso@mit.edu \
--cc=yamada.masahiro@socionext.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).