Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:18 as permitted sender) client-ip=2620:137:e000::1:18;
MIME-Version: 1.0
References: <20220318021314.3225240-1-davidgow@google.com> <20220318021314.3225240-3-davidgow@google.com>
In-Reply-To: <20220318021314.3225240-3-davidgow@google.com>
From:   Daniel Latypov <dlatypov@google.com>
Date:   Mon, 4 Apr 2022 16:13:47 -0500
Message-ID: <CAGS_qxqtMpjKX+CMF6eBUWfsc-TKR9-Bk+hYM=PHa0_wUtQQuA@mail.gmail.com>
Subject: Re: [RFC PATCH 2/2] kunit: expose ftrace-based API for stubbing out
 functions during tests
To:     David Gow <davidgow@google.com>
Cc:     Brendan Higgins <brendanhiggins@google.com>,
        Kees Cook <keescook@chromium.org>,
        Shuah Khan <skhan@linuxfoundation.org>,
        Steven Rostedt <rostedt@goodmis.org>,
        kunit-dev@googlegroups.com, linux-kselftest@vger.kernel.org,
        linux-kernel@vger.kernel.org
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

On Thu, Mar 17, 2022 at 9:13 PM David Gow <davidgow@google.com> wrote:
> +
> +/** KUNIT_STUBBABLE - marks a function as stubbable when stubbing support is
> + * enabled.
> + *
> + * Stubbing uses ftrace internally, so we can only stub out functions when they
> + * are not inlined. This macro eavlautes to noinline when stubbing support is

Just noting a couple typos lest they be forgotten:
*evaluates

> + * enabled to thus make it safe.
> + *

<snip>

> + *
> + *     void replacement_func(int n)
> + *     {
> + *             pr_info("replacement_func() called with %d", n);
> + *             return 42;
> + *     }
> + *
> + *     void example_test(struct kunit *test)
> + *     {
> + *             kunit_active_ftrace_stub(test, real_func, replacement_func);

*activate