linux.git/drivers/video/fbdev/sis, branch v6.12.80

fbdev: sisfb: Fix strbuf array overflow

2024-09-27T22:42:11+00:00

The values of the variables xres and yres are placed in strbuf.
These variables are obtained from strbuf1.
The strbuf1 array contains digit characters
and a space if the array contains non-digit characters.
Then, when executing sprintf(strbuf, "%ux%ux8", xres, yres);
more than 16 bytes will be written to strbuf.
It is suggested to increase the size of the strbuf array to 24.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Signed-off-by: Andrey Shumilin 
Signed-off-by: Helge Deller

fbdev: sisfb: hide unused variables

2024-04-03T12:38:07+00:00

Building with W=1 shows that a couple of variables in this driver are only
used in certain configurations:

drivers/video/fbdev/sis/init301.c:239:28: error: 'SiS_Part2CLVX_6' defined but not used [-Werror=unused-const-variable=]
  239 | static const unsigned char SiS_Part2CLVX_6[] = {   /* 1080i */
      |                            ^~~~~~~~~~~~~~~
drivers/video/fbdev/sis/init301.c:230:28: error: 'SiS_Part2CLVX_5' defined but not used [-Werror=unused-const-variable=]
  230 | static const unsigned char SiS_Part2CLVX_5[] = {   /* 750p */
      |                            ^~~~~~~~~~~~~~~
drivers/video/fbdev/sis/init301.c:211:28: error: 'SiS_Part2CLVX_4' defined but not used [-Werror=unused-const-variable=]
  211 | static const unsigned char SiS_Part2CLVX_4[] = {   /* PAL */
      |                            ^~~~~~~~~~~~~~~
drivers/video/fbdev/sis/init301.c:192:28: error: 'SiS_Part2CLVX_3' defined but not used [-Werror=unused-const-variable=]
  192 | static const unsigned char SiS_Part2CLVX_3[] = {  /* NTSC, 525i, 525p */
      |                            ^~~~~~~~~~~~~~~
drivers/video/fbdev/sis/init301.c:184:28: error: 'SiS_Part2CLVX_2' defined but not used [-Werror=unused-const-variable=]
  184 | static const unsigned char SiS_Part2CLVX_2[] = {
      |                            ^~~~~~~~~~~~~~~
drivers/video/fbdev/sis/init301.c:176:28: error: 'SiS_Part2CLVX_1' defined but not used [-Werror=unused-const-variable=]
  176 | static const unsigned char SiS_Part2CLVX_1[] = {
      |                            ^~~~~~~~~~~~~~~

This started showing up after the definitions were moved into the
source file from the header, which was not flagged by the compiler.
Move the definition into the appropriate #ifdef block that already
exists next to them.

Fixes: 5908986ef348 ("video: fbdev: sis: avoid mismatched prototypes")
Signed-off-by: Arnd Bergmann 
Signed-off-by: Helge Deller

fbdev: sis: Error out if pixclock equals zero

2024-01-21T08:00:14+00:00

The userspace program could pass any values to the driver through
ioctl() interface. If the driver doesn't check the value of pixclock,
it may cause divide-by-zero error.

In sisfb_check_var(), var->pixclock is used as a divisor to caculate
drate before it is checked against zero. Fix this by checking it
at the beginning.

This is similar to CVE-2022-3061 in i740fb which was fixed by
commit 15cf0b8.

Signed-off-by: Fullway Wang 
Signed-off-by: Helge Deller

fbdev/sis: Remove dependency on screen_info

2024-01-12T11:38:37+00:00

When built-in, the sis driver tries to detect the current display mode
from the global screen_info state. That state is only for architecture
and firmware code. Drivers should not use it directly as it's not
guaranteed to contain valid information.

Remove the mode-detection code from sis. Drivers that want to detect a
pre-set mode on probe should read the hardware registers directly.

Signed-off-by: Thomas Zimmermann 
Signed-off-by: Helge Deller

fbdev/sisfb: Initialize fb_ops to fbdev I/O-memory helpers

2023-10-19T10:56:39+00:00

Initialize the instance of struct fb_ops with fbdev initializer
macros for framebuffers in I/O address space. Set the read/write,
draw and mmap callbacks to the correct implementation and avoid
implicit defaults. Also select the necessary I/O helpers in Kconfig.

Fbdev drivers sometimes rely on the callbacks being NULL for a
default implementation to be invoked; hence requiring the I/O
helpers to be built in any case. Setting all callbacks in all
drivers explicitly will allow to make the I/O helpers optional.
This benefits systems that do not use these functions.

No functional changes.

Signed-off-by: Thomas Zimmermann 
Acked-by: Javier Martinez Canillas 
Link: https://patchwork.freedesktop.org/patch/msgid/20230927074722.6197-36-tzimmermann@suse.de

fbdev: Remove FBINFO_FLAG_DEFAULT from framebuffer_alloc()'ed structs

2023-07-24T14:50:39+00:00

The flag FBINFO_FLAG_DEFAULT is 0 and has no effect, as struct
fbinfo.flags has been allocated to zero by framebuffer_alloc(). So
do not set it.

Flags should signal differences from the default values. After cleaning
up all occurrences of FBINFO_DEFAULT, the token will be removed.

v4:
	* clarify commit message (Geert, Dan)
v2:
	* fix commit message (Miguel)

Signed-off-by: Thomas Zimmermann 
Acked-by: Sam Ravnborg 
Cc: Jaya Kumar 
Cc: Helge Deller 
Cc: Peter Jones 
Cc: Sascha Hauer 
Cc: Pengutronix Kernel Team 
Cc: Shawn Guo 
Cc: Fabio Estevam 
Cc: NXP Linux Team 
Cc: Maik Broemme 
Cc: Jingoo Han 
Cc: Sudip Mukherjee 
Cc: Teddy Wang 
Cc: Michal Januszewski 
Link: https://patchwork.freedesktop.org/patch/msgid/20230715185343.7193-15-tzimmermann@suse.de

fbdev: Remove FBINFO_DEFAULT from framebuffer_alloc()'ed structs

2023-07-24T14:50:38+00:00

The flag FBINFO_DEFAULT is 0 and has no effect, as struct fbinfo.flags
has been allocated to zero by framebuffer_alloc(). So do not set it.

Flags should signal differences from the default values. After cleaning
up all occurrences of FBINFO_DEFAULT, the token will be removed.

v4:
	* clarify commit message (Geert, Dan)
v2:
	* fix commit message (Miguel)

Signed-off-by: Thomas Zimmermann 
Acked-by: Sam Ravnborg 
Cc: Helge Deller 
Cc: Nicolas Ferre 
Cc: Benjamin Herrenschmidt 
Cc: Ferenc Bakonyi 
Cc: "K. Y. Srinivasan" 
Cc: Haiyang Zhang 
Cc: Wei Liu 
Cc: Dexuan Cui 
Cc: Antonino Daplas 
Cc: Maik Broemme 
Cc: Michael Ellerman 
Cc: Nicholas Piggin 
Cc: Christophe Leroy 
Cc: Kristoffer Ericson 
Cc: Hans de Goede 
Cc: Steve Glendinning 
Cc: Bernie Thompson 
Cc: Florian Tobias Schandinat 
Link: https://patchwork.freedesktop.org/patch/msgid/20230715185343.7193-6-tzimmermann@suse.de

Backmerge tag 'v6.1-rc6' into drm-next

2022-11-24T01:05:43+00:00

Linux 6.1-rc6

This is needed for drm-misc-next and tegra.

Signed-off-by: Dave Airlie

fbdev: Add support for the nomodeset kernel parameter

2022-11-16T12:26:25+00:00

Support the kernel's nomodeset parameter for all PCI-based fbdev
drivers that use aperture helpers to remove other, hardware-agnostic
graphics drivers.

The parameter is a simple way of using the firmware-provided scanout
buffer if the hardware's native driver is broken. The same effect
could be achieved with per-driver options, but the importance of the
graphics output for many users makes a single, unified approach
worthwhile.

With nomodeset specified, the fbdev driver module will not load. This
unifies behavior with similar DRM drivers. In DRM helpers, modules
first check the nomodeset parameter before registering the PCI
driver. As fbdev has no such module helpers, we have to modify each
driver individually.

The name 'nomodeset' is slightly misleading, but has been chosen for
historical reasons. Several drivers implemented it before it became a
general option for DRM. So keeping the existing name was preferred over
introducing a new one.

v2:
	* print a warning if a driver does not init (Helge)
	* wrap video_firmware_drivers_only() in helper

Signed-off-by: Thomas Zimmermann 
Reviewed-by: Javier Martinez Canillas 
Link: https://patchwork.freedesktop.org/patch/msgid/20221111133024.9897-3-tzimmermann@suse.de

fbdev: sisfb: use explicitly signed char

2022-10-24T18:28:41+00:00

With char becoming unsigned by default, and with `char` alone being
ambiguous and based on architecture, signed chars need to be marked
explicitly as such. This fixes warnings like:

drivers/video/fbdev/sis/init301.c:3549 SiS_GetCRT2Data301() warn: 'SiS_Pr->SiS_EModeIDTable[ModeIdIndex]->ROMMODEIDX661' is unsigned

Cc: Thomas Winischhofer 
Cc: Greg Kroah-Hartman 
Cc: Helge Deller 
Cc: linux-usb@vger.kernel.org
Cc: linux-fbdev@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Jason A. Donenfeld 
Signed-off-by: Helge Deller