From: Daniel Latypov <dlatypov@google.com>
To: Randy Dunlap <rdunlap@infradead.org>,
David Gow <davidgow@google.com>,
Brendan Higgins <brendanhiggins@google.com>
Cc: Andy Shevchenko <andriy.shevchenko@intel.com>,
Trent Piepho <tpiepho@gmail.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
andy@kernel.org, Andrew Morton <akpm@linux-foundation.org>,
Oskar Schirmer <oskar@scara.com>, Yiyuan Guo <yguoaz@gmail.com>
Subject: Re: [PATCH] lib/math/rational.c: Fix divide by zero
Date: Mon, 24 May 2021 16:38:13 -0700 [thread overview]
Message-ID: <CAGS_qxrUGW4uyMUQtEYWX710LxPs23B=uOJfhZSvMV1yaVa6jA@mail.gmail.com> (raw)
In-Reply-To: <bd3fceb3-4d49-befb-ee3b-bc01ef5d6827@infradead.org>
On Mon, May 24, 2021 at 4:30 PM Randy Dunlap <rdunlap@infradead.org> wrote:
>
> On 5/24/21 3:56 PM, Daniel Latypov wrote:
> > On Mon, May 24, 2021 at 3:04 PM Randy Dunlap <rdunlap@infradead.org> wrote:
> >>
> >> On 5/24/21 9:55 AM, Daniel Latypov wrote:
> >>> diff --git a/lib/math/Kconfig b/lib/math/Kconfig
> >>> index f19bc9734fa7..20460b567493 100644
> >>> --- a/lib/math/Kconfig
> >>> +++ b/lib/math/Kconfig
> >>> @@ -15,3 +15,14 @@ config PRIME_NUMBERS
> >>>
> >>> config RATIONAL
> >>> bool
> >>> +
> >>> +config RATIONAL_KUNIT_TEST
> >>> + tristate "KUnit test for rational number support" if !KUNIT_ALL_TESTS
> >>> + # depends on KUNIT && RATIONAL # this is how it should work, but
> >>> + depends on KUNIT
> >>> + select RATIONAL # I don't grok kconfig enough to know why this
> >>
> >> Only to set the symbol CONFIG_RATIONAL.
> >> Then when 'make' descends into the lib/math/ subdir and looks at its Makefile,
> >> it will decide to build the binary rational.o.
> >>
> >> obj-$(CONFIG_RATIONAL) += rational.o
> >>
> >
> > Ack, I understand that much.
>
> Oh! Clearly I misunderstood the problem.
>
> I had to look thru 60 config files before I found one where CONFIG_RATIONAL
> was not set.
>
> And I'm still not sure, but I believe that it's because it has to be set
> by some other Kconfig entry doing a 'select' on it.
>
> Here are the kconfigs that select it (on i386, where I found it not set):
>
> - COMMON_CLK [=n] && !HAVE_LEGACY_CLK [=n]
> - SERIAL_8250_LPSS [=n] && TTY [=n] && HAS_IOMEM [=y] && SERIAL_8250 [=n] && PCI [=n] && (X86 [=y] || COMPILE_TEST [=y])
> - SERIAL_8250_MID [=n] && TTY [=n] && HAS_IOMEM [=y] && SERIAL_8250 [=n] && PCI [=n] && (X86 [=y] || COMPILE_TEST [=y])
> - SERIAL_IMX [=n] && TTY [=n] && HAS_IOMEM [=y] && (ARCH_MXC || COMPILE_TEST [=y])
> - VIDEO_V4L2 [=n] && MEDIA_SUPPORT [=n] && (I2C [=y] || I2C [=y]=n) && VIDEO_DEV [=n]
> - SND_SOC_ROCKCHIP_PDM [=n] && SOUND [=n] && !UML && SND [=n] && SND_SOC [=n] && CLKDEV_LOOKUP [=n] && SND_SOC_ROCKCHIP [=n]
> - COMMON_CLK_QCOM [=n] && COMMON_CLK [=n] && OF [=y] && (ARCH_QCOM || COMPILE_TEST [=y])
>
> but my test config has none of those enabled, so I cannot set RATIONAL.
>
> I guess the easiest solution is to have KUNIT or some sub-KUNIT test
> just select RATIONAL.
Yeah, the easiest thing would be to keep the `select RATIONAL` that I
showed in the example patch.
+David Gow +Brendan Higgins as they both particularly wanted to avoid
having any tests `select` their dependencies, however.
>
> > My confusion is why this doesn't work:
> >
> > $ ./tools/testing/kunit/kunit.py run --kunitconfig /dev/stdin <<EOF
> > CONFIG_KUNIT=y
> > CONFIG_RATIONAL=y
> > EOF
> > ...
> > ERROR:root:Provided Kconfig is not contained in validated .config.
> > Following fields found in kunitconfig, but not in .config:
> > CONFIG_RATIONAL=y
> >
> > What it's complaining about is that `make ARCH=um olddefconfig` is
> > leaving CONFIG_RATIONAL=y unset.
> >
> > Stripping out kunit.py, it's this:
> >
> > $ echo -e 'CONFIG_KUNIT=y\nCONFIG_RATIONAL=y' > .kunit/.config
> > $ make ARCH=um olddefconfig O=.kunit
> > $ grep RATIONAL .kunit/.config
> >
> > I'm not versed in Kconfig enough to know why CONFIG_RATIONAL=y is
> > getting removed.
> >
> >>
> >>> is necessary
> >>> + default KUNIT_ALL_TESTS
> >>> + help
> >>> + This builds unit tests for the rational number support.
> >>> +
> >>> + If unsure, say N.
>
>
> --
> ~Randy
>
next prev parent reply other threads:[~2021-05-24 23:38 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-23 0:18 [PATCH] lib/math/rational.c: Fix divide by zero Trent Piepho
2021-05-24 10:51 ` Andy Shevchenko
2021-05-24 16:55 ` Daniel Latypov
2021-05-24 22:04 ` Randy Dunlap
2021-05-24 22:56 ` Daniel Latypov
2021-05-24 23:30 ` Randy Dunlap
2021-05-24 23:38 ` Daniel Latypov [this message]
2021-05-25 0:42 ` David Gow
2021-05-25 1:49 ` Randy Dunlap
2021-05-25 1:57 ` David Gow
2021-05-25 5:08 ` Trent Piepho
2021-05-24 20:17 ` Trent Piepho
2021-05-24 20:35 ` Daniel Latypov
2021-05-25 9:02 ` Andy Shevchenko
2021-05-25 9:21 ` Trent Piepho
2021-05-25 12:03 ` Andy Shevchenko
2021-05-25 17:10 ` Daniel Latypov
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