From: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
To: Jia-Ju Bai <baijiaju1990@gmail.com>
Cc: dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [BUG] video: fbdev: broadsheetfb: Possible null function pointers
Date: Fri, 27 Jul 2018 10:06:45 +0200 [thread overview]
Message-ID: <5031064.Ea5icxSZ3H@amdc3058> (raw)
In-Reply-To: <c95d4381-1278-e561-29d8-ae84be2c680e@gmail.com>
On Friday, July 27, 2018 09:49:41 AM Jia-Ju Bai wrote:
>
> On 2018/7/26 22:34, Bartlomiej Zolnierkiewicz wrote:
> > On Thursday, July 26, 2018 10:17:44 PM bai wrote:
> >> In Linux-4.16, drivers/video/fbdev/broadsheetfb.c,
> >>
> >> 158. static void broadsheet_mmio_send_cmdargs(...) {
> >> ......
> >> 163. par->board->mmio_write(...);
> >> ......
> >> 166. par->board->mmio_write(...);
> >> 167. }
> >>
> >> For x86 kernel configuration, I find that there is no assignment of the
> >> function pointer ".mmio_write" in the kernel code.
> >> So calling the function pointer in lines 163 and 166 may cause a null
> >> pointer dereference.
> >>
> >> In this file, there are many calls to this function pointer...
> > This is a platform driver and it won't be used on x86 (actually it is
> > used only by single ARM PXA board). The dependency for FB_BROADSHEET
> > in Kconfig file could be improved to i.e.
> >
> > depends on FB && (ARCH_PXA || COMPILE_TEST)
> >
> > but there is no bug there.
>
> Thanks for the reply :)
> So I want to submit a patch of updating Kconfig in
> drivers/video/fbdev/Kconfig:
>
> config FB_BROADSHEET
> tristate "E-Ink Broadsheet/Epson S1D13521 controller support"
> - depends on FB
> + depends on FB && (ARCH_PXA || COMPILE_TEST)
> select FB_SYS_FILLRECT
> select FB_SYS_COPYAREA
> select FB_SYS_IMAGEBLIT
> select FB_SYS_FOPS
> select FB_DEFERRED_IO
>
>
> Do you think it is okay?
Please read Documentation/process/submitting-patches.rst.
Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics
WARNING: multiple messages have this Message-ID (diff)
From: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
To: Jia-Ju Bai <baijiaju1990@gmail.com>
Cc: linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org,
dri-devel@lists.freedesktop.org
Subject: Re: [BUG] video: fbdev: broadsheetfb: Possible null function pointers
Date: Fri, 27 Jul 2018 08:06:45 +0000 [thread overview]
Message-ID: <5031064.Ea5icxSZ3H@amdc3058> (raw)
In-Reply-To: <c95d4381-1278-e561-29d8-ae84be2c680e@gmail.com>
On Friday, July 27, 2018 09:49:41 AM Jia-Ju Bai wrote:
>
> On 2018/7/26 22:34, Bartlomiej Zolnierkiewicz wrote:
> > On Thursday, July 26, 2018 10:17:44 PM bai wrote:
> >> In Linux-4.16, drivers/video/fbdev/broadsheetfb.c,
> >>
> >> 158. static void broadsheet_mmio_send_cmdargs(...) {
> >> ......
> >> 163. par->board->mmio_write(...);
> >> ......
> >> 166. par->board->mmio_write(...);
> >> 167. }
> >>
> >> For x86 kernel configuration, I find that there is no assignment of the
> >> function pointer ".mmio_write" in the kernel code.
> >> So calling the function pointer in lines 163 and 166 may cause a null
> >> pointer dereference.
> >>
> >> In this file, there are many calls to this function pointer...
> > This is a platform driver and it won't be used on x86 (actually it is
> > used only by single ARM PXA board). The dependency for FB_BROADSHEET
> > in Kconfig file could be improved to i.e.
> >
> > depends on FB && (ARCH_PXA || COMPILE_TEST)
> >
> > but there is no bug there.
>
> Thanks for the reply :)
> So I want to submit a patch of updating Kconfig in
> drivers/video/fbdev/Kconfig:
>
> config FB_BROADSHEET
> tristate "E-Ink Broadsheet/Epson S1D13521 controller support"
> - depends on FB
> + depends on FB && (ARCH_PXA || COMPILE_TEST)
> select FB_SYS_FILLRECT
> select FB_SYS_COPYAREA
> select FB_SYS_IMAGEBLIT
> select FB_SYS_FOPS
> select FB_DEFERRED_IO
>
>
> Do you think it is okay?
Please read Documentation/process/submitting-patches.rst.
Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics
WARNING: multiple messages have this Message-ID (diff)
From: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
To: Jia-Ju Bai <baijiaju1990@gmail.com>
Cc: linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org,
dri-devel@lists.freedesktop.org
Subject: Re: [BUG] video: fbdev: broadsheetfb: Possible null function pointers
Date: Fri, 27 Jul 2018 10:06:45 +0200 [thread overview]
Message-ID: <5031064.Ea5icxSZ3H@amdc3058> (raw)
In-Reply-To: <c95d4381-1278-e561-29d8-ae84be2c680e@gmail.com>
On Friday, July 27, 2018 09:49:41 AM Jia-Ju Bai wrote:
>
> On 2018/7/26 22:34, Bartlomiej Zolnierkiewicz wrote:
> > On Thursday, July 26, 2018 10:17:44 PM bai wrote:
> >> In Linux-4.16, drivers/video/fbdev/broadsheetfb.c,
> >>
> >> 158. static void broadsheet_mmio_send_cmdargs(...) {
> >> ......
> >> 163. par->board->mmio_write(...);
> >> ......
> >> 166. par->board->mmio_write(...);
> >> 167. }
> >>
> >> For x86 kernel configuration, I find that there is no assignment of the
> >> function pointer ".mmio_write" in the kernel code.
> >> So calling the function pointer in lines 163 and 166 may cause a null
> >> pointer dereference.
> >>
> >> In this file, there are many calls to this function pointer...
> > This is a platform driver and it won't be used on x86 (actually it is
> > used only by single ARM PXA board). The dependency for FB_BROADSHEET
> > in Kconfig file could be improved to i.e.
> >
> > depends on FB && (ARCH_PXA || COMPILE_TEST)
> >
> > but there is no bug there.
>
> Thanks for the reply :)
> So I want to submit a patch of updating Kconfig in
> drivers/video/fbdev/Kconfig:
>
> config FB_BROADSHEET
> tristate "E-Ink Broadsheet/Epson S1D13521 controller support"
> - depends on FB
> + depends on FB && (ARCH_PXA || COMPILE_TEST)
> select FB_SYS_FILLRECT
> select FB_SYS_COPYAREA
> select FB_SYS_IMAGEBLIT
> select FB_SYS_FOPS
> select FB_DEFERRED_IO
>
>
> Do you think it is okay?
Please read Documentation/process/submitting-patches.rst.
Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics
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next prev parent reply other threads:[~2018-07-27 8:06 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20180726141748epcas1p28f6f11fea0152ed22113351e3a0affbc@epcas1p2.samsung.com>
2018-07-26 14:17 ` [BUG] video: fbdev: broadsheetfb: Possible null function pointers bai
2018-07-26 14:17 ` bai
2018-07-26 14:34 ` Bartlomiej Zolnierkiewicz
2018-07-26 14:34 ` Bartlomiej Zolnierkiewicz
2018-07-27 1:49 ` Jia-Ju Bai
2018-07-27 1:49 ` Jia-Ju Bai
2018-07-27 8:06 ` Bartlomiej Zolnierkiewicz [this message]
2018-07-27 8:06 ` Bartlomiej Zolnierkiewicz
2018-07-27 8:06 ` Bartlomiej Zolnierkiewicz
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