Re: [PATCH] drm/i915/kvmgt: avoid dereferencing a potentially null info pointer

[Frans Klaver]

On Thu, Mar 23, 2017 at 1:22 PM, Colin King  wrote:
> From: Colin Ian King 
>
> info is being checked to see if it is a null pointer, however, vpgu is
> dereferencing info before this check, leading to a potential null
> pointer dereference.  If info is null, then the error message being
> printed by macro gvt_vgpu_err and this requires vpgu to exist. We can
> use a null vpgu as the macro has a sanity check to see if vpgu is null,
> so this is OK.
>
> Detected with CoverityScan, CID#1420672 ("Dereference nefore null check")

s,nefore,before,


>
> Fixes: 695fbc08d80f ("drm/i915/gvt: replace the gvt_err with gvt_vgpu_err")
> Signed-off-by: Colin Ian King 
> ---
>  drivers/gpu/drm/i915/gvt/kvmgt.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c 
> b/drivers/gpu/drm/i915/gvt/kvmgt.c
> index 1ea3eb270de8..f8619a772c44 100644
> --- a/drivers/gpu/drm/i915/gvt/kvmgt.c
> +++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
> @@ -1339,9 +1339,9 @@ static int kvmgt_guest_init(struct mdev_device *mdev)
>
>  static bool kvmgt_guest_exit(struct kvmgt_guest_info *info)
>  {
> -   struct intel_vgpu *vgpu = info->vgpu;
> -
> if (!info) {
> +   struct intel_vgpu *vgpu = NULL;
> +
> gvt_vgpu_err("kvmgt_guest_info invalid\n");
> return false;
> }

Does this mean the original gvt_err() macro is no longer there?

And apparently gvt_vgpu_err is a macro that depends on the specifics
of its environment? Yikes.

Cheers,
Frans
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[PATCH 05/98] exynos_drm.h: use __u64 from linux/types.h

[Frans Klaver]

On Mon, Jun 1, 2015 at 11:08 AM, Christian König
 wrote:
> Yeah, completely agree with Linus on the visibility problem and that's
> exactly the reason why we don't include  in the kernel header and
> expect userspace to define the ISO types somewhere.
>
> But using the types from "include/linux/types.h" and especially including it
> into the uapi headers doesn't make the situation better, but rather worse.
>
> With this step we not only make the headers depend on another header that
> isn't part of the uapi, but also pollute the user space namespace with __sXX
> and __uXX types which aren't defined anywhere else.

These __uXX and __sXX types are defined in
include/uapi/asm-generic/ll64.h and pulled in by
include/uapi/linux/types.h. Including linux/types.h is therefore
valid.

Frans

[Spice-devel] [PATCH 00/11] Miscellaneous stability patches

[Frans Klaver]

On Thu, May 28, 2015 at 4:10 PM, Frediano Ziglio  wrote:
>
>> also indicating in each patch what is a right now fix and what isn't.
>
> What do you mean by right fix or not ?

He probably meant indicating whether it is an urgent fix.

Frans

[bisected] nouveau dual monitor setup broken

[Frans Klaver]

On Fri, Oct 31, 2014 at 11:34:45AM +0100, Roy Spliet wrote:
> 
> It does ring a tiny bell: please check out 
> https://bugs.freedesktop.org/show_bug.cgi?id=85160 and try the fix proposed 
> in comment #7.

Yup, that seems to fix things. As far as I'm concerned, that patch is

Tested-by: Frans Klaver 

Thanks,
Frans

[bisected] nouveau dual monitor setup broken

[Frans Klaver]

Hi there,

My dual monitor setup on the Dell Precision M4500 is broken by commit
1dce6264045cd23e9c07574ed0bb31c7dce9354f ("drm/nv50/kms: Set VBLANK time
in modeset script"). I am no longer able to have more than one monitor
active.

Full dmesg can be found at http://pastebin.com/7e68yMRy, but I've
included an excerpt as well.

[0.00] Linux version 3.18.0-rc2-00106-ga7ca10f (frans at bwaark) (gcc 
version 4.8.2 (Gentoo 4.8.2 p1.3r1, pie-0.5.8r1) ) #27 SMP Fri Oct 31 08:30:15 
CET 2014
...
[1.920869] fb: switching to nouveaufb from VESA VGA
[1.953160] Console: switching to colour dummy device 80x25
[1.965235] nouveau  [  DEVICE][:01:00.0] BOOT0  : 0x0a5e00a2
[1.965247] nouveau  [  DEVICE][:01:00.0] Chipset: GT216 (NVA5)
[1.965255] nouveau  [  DEVICE][:01:00.0] Family : NV50
[1.965303] nouveau  [   VBIOS][:01:00.0] checking PRAMIN for image...
[2.017175] tsc: Refined TSC clocksource calibration: 1595.999 MHz
[2.060360] nouveau  [   VBIOS][:01:00.0] ... appears to be valid
[2.060369] nouveau  [   VBIOS][:01:00.0] using image from PRAMIN
[2.060704] nouveau  [   VBIOS][:01:00.0] BIT signature found
[2.060713] nouveau  [   VBIOS][:01:00.0] version 70.16.5c.01.06
[2.075227] ACPI: Battery Slot [BAT1] (battery absent)
[2.075329] nouveau :01:00.0: irq 29 for MSI/MSI-X
[2.075342] nouveau  [ PMC][:01:00.0] MSI interrupts enabled
[2.075376] nouveau  [ PFB][:01:00.0] RAM type: DDR3
[2.075380] nouveau  [ PFB][:01:00.0] RAM size: 1024 MiB
[2.075384] nouveau  [ PFB][:01:00.0]ZCOMP: 1920 tags
[2.079057] nouveau  [VOLT][:01:00.0] GPU voltage: 93uv
[2.108300] nouveau  [  PTHERM][:01:00.0] FAN control: none / external
[2.108328] nouveau  [  PTHERM][:01:00.0] fan management: automatic
[2.108338] nouveau  [  PTHERM][:01:00.0] internal sensor: yes
[2.128401] nouveau  [ CLK][:01:00.0] 03: core 135 MHz shader 270 
MHz memory 135 MHz
[2.128414] nouveau  [ CLK][:01:00.0] 07: core 405 MHz shader 810 
MHz memory 324 MHz
[2.128426] nouveau  [ CLK][:01:00.0] 0f: core 550 MHz shader 1210 
MHz memory 790 MHz
[2.128469] nouveau  [ CLK][:01:00.0] --: core 405 MHz shader 810 
MHz memory 324 MHz
[2.129501] [TTM] Zone  kernel: Available graphics memory: 4080170 kiB
[2.129514] [TTM] Zone   dma32: Available graphics memory: 2097152 kiB
[2.129522] [TTM] Initializing pool allocator
[2.129540] [TTM] Initializing DMA pool allocator
[2.129575] nouveau  [ DRM] VRAM: 1024 MiB
[2.129584] nouveau  [ DRM] GART: 1048576 MiB
[2.129596] nouveau  [ DRM] TMDS table version 2.0
[2.129605] nouveau  [ DRM] DCB version 4.0
[2.129615] nouveau  [ DRM] DCB outp 00: 048003b6 0f220014
[2.129626] nouveau  [ DRM] DCB outp 01: 02033300 
[2.129637] nouveau  [ DRM] DCB outp 02: 028113a6 0f220010
[2.129647] nouveau  [ DRM] DCB outp 03: 02011362 00020010
[2.129657] nouveau  [ DRM] DCB outp 04: 088223c6 0f220010
[2.129667] nouveau  [ DRM] DCB outp 05: 08022382 00020010
[2.129676] nouveau  [ DRM] DCB conn 00: 2047
[2.129687] nouveau  [ DRM] DCB conn 01: 00101146
[2.129696] nouveau  [ DRM] DCB conn 02: 00410246
[2.129705] nouveau  [ DRM] DCB conn 03: 0300
[2.183136] [drm] Supports vblank timestamp caching Rev 2 (21.10.2013).
[2.183142] [drm] Driver supports precise vblank timestamp query.
[2.229885] nouveau  [ DRM] MM: using COPY for buffer copies
[2.545100] nouveau  [ DRM] allocated 1920x1080 fb: 0x7, bo 
880225962c00
[2.545330] fbcon: nouveaufb (fb0) is primary device
[2.596432] nouveau E[   PDISP][:01:00.0] INVALID_STATE [UNK05] chid 0 
mthd 0x0080 data 0x
[2.596435] nouveau E[   PDISP][:01:00.0] Core:
[2.596441] nouveau E[   PDISP][:01:00.0]0x0084: 0x01e00280 -> 
0x
[2.596447] nouveau E[   PDISP][:01:00.0]0x0088: 0xf000  

[2.596450] nouveau E[   PDISP][:01:00.0] Core - DAC 0:
[2.596455] nouveau E[   PDISP][:01:00.0]0x0400: 0x  

[2.596460] nouveau E[   PDISP][:01:00.0]0x0404: 0x  

[2.596465] nouveau E[   PDISP][:01:00.0]0x0420: 0x0001  

[2.596468] nouveau E[   PDISP][:01:00.0] Core - DAC 1:
[2.596473] nouveau E[   PDISP][:01:00.0]0x0480: 0x  

[2.596477] nouveau E[   PDISP][:01:00.0]0x0484: 0x  

[2.596482] nouveau E[   PDISP][:01:00.0]0x04a0: 0x0001  

[2.596484] nouveau E[   PDISP][:01:00.0] Core - DAC 2:
[2.596489] nouveau E[   PDISP][:01:00.0]0x0500: 0x  

[2.596494] nouveau E[   PDISP][:01:00.0]0x0504: