linux-kernel - Re: [PATCH v2 01/10] string: provide strends()

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Message-ID: <aPkQi_Zn-17JKG0s@smile.fi.intel.com>
Date: Wed, 22 Oct 2025 20:12:43 +0300
From: Andy Shevchenko <andriy.shevchenko@...el.com>
To: Bartosz Golaszewski <brgl@...ev.pl>
Cc: Kees Cook <kees@...nel.org>, Mika Westerberg <westeri@...nel.org>,
	Dmitry Torokhov <dmitry.torokhov@...il.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Linus Walleij <linus.walleij@...aro.org>,
	Manivannan Sadhasivam <mani@...nel.org>,
	Rob Herring <robh@...nel.org>,
	Krzysztof Kozlowski <krzk+dt@...nel.org>,
	Conor Dooley <conor+dt@...nel.org>,
	Saravana Kannan <saravanak@...gle.com>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Andy Shevchenko <andy@...nel.org>,
	Catalin Marinas <catalin.marinas@....com>,
	Will Deacon <will@...nel.org>,
	Srinivas Kandagatla <srini@...nel.org>,
	Liam Girdwood <lgirdwood@...il.com>,
	Mark Brown <broonie@...nel.org>, Jaroslav Kysela <perex@...ex.cz>,
	Takashi Iwai <tiwai@...e.com>, linux-hardening@...r.kernel.org,
	linux-kernel@...r.kernel.org, linux-gpio@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org, linux-sound@...r.kernel.org,
	linux-arm-msm@...r.kernel.org,
	Bartosz Golaszewski <bartosz.golaszewski@...aro.org>
Subject: Re: [PATCH v2 01/10] string: provide strends()

On Wed, Oct 22, 2025 at 05:36:33PM +0200, Bartosz Golaszewski wrote:
> On Wed, Oct 22, 2025 at 5:25 PM Andy Shevchenko
> <andriy.shevchenko@...el.com> wrote:
> > On Wed, Oct 22, 2025 at 03:10:40PM +0200, Bartosz Golaszewski wrote:

...

> > > +static void string_test_strends(struct kunit *test)
> > > +{
> > > +     KUNIT_EXPECT_TRUE(test, strends("foo-bar", "bar"));
> > > +     KUNIT_EXPECT_TRUE(test, strends("foo-bar", "-bar"));
> > > +     KUNIT_EXPECT_TRUE(test, strends("foobar", "foobar"));
> > > +     KUNIT_EXPECT_TRUE(test, strends("foobar", ""));
> > > +     KUNIT_EXPECT_FALSE(test, strends("bar", "foobar"));
> > > +     KUNIT_EXPECT_FALSE(test, strends("", "foo"));
> > > +     KUNIT_EXPECT_FALSE(test, strends("foobar", "ba"));
> > > +     KUNIT_EXPECT_TRUE(test, strends("", ""));
> > > +}
> >
> > Have you checked the binary file? If you want this to be properly implemented,
> > generate the suffix. (Actually making the function static inline makes my point
> > really visible)
> 
> Andy, this is bikeshedding. This is literally the least important
> piece of this series. It doesn't matter for the big picture whether
> this is inlined or not.

It's definitely not a bikeshedding. I try to keep a bit consistency here and
I don't see the point of bloating a kernel (binary as well) for the function
that just a couple of lines with simple basic calls.

Also note that with inlined version strlen() for string literals will be
calculated at _compile-time_! This is clear benefit.

Really, library code is not as simple as dropping something to somewhere...

-- 
With Best Regards,
Andy Shevchenko