[ Upstream commit 688cf598665851b9e8cb5083ff1d208ce43d10ff ]

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 <arnd@arndb.de>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit e421946be7d9bf545147bea8419ef8239cb7ca52 ]

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 <fullwaywang@outlook.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit 3eb8fccc244bfb41a7961969e4db280d44911226 ]

The second operand of a '&&' operator has no impact on expression
result for cases 400 and 512 in SiS_GetModeID().

Judging by the logic and the names of the variables, in both cases a
typo was made.

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

Signed-off-by: Rustam Subkhankulov <subkhankulov@ispras.ru>
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit ad6f93e9cd56f0b10e9b22e3e137d17a1a035242 ]

Clang static analysis reports this representative error

init.c:2501:18: warning: Array access (from variable 'queuedata') results
  in a null pointer dereference
      templ |= ((queuedata[i] & 0xc0) << 3);

This is the problem block of code

   if(ModeNo > 0x13) {
      ...
      if(SiS_Pr->ChipType == SIS_730) {
	 queuedata = &FQBQData730[0];
      } else {
	 queuedata = &FQBQData[0];
      }
   } else {

   }

queuedata is not set in the else block

Reviewing the old code, the arrays FQBQData730 and FQBQData were
used directly.

So hoist the setting of queuedata out of the if-else block.

Fixes: 544393fe584d ("[PATCH] sisfb update")
Signed-off-by: Tom Rix <trix@redhat.com>
Cc: Thomas Winischhofer <thomas@winischhofer.net>
Cc: Andrew Morton <akpm@osdl.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200805145208.17727-1-trix@redhat.com
Signed-off-by: Sasha Levin <sashal@kernel.org>

commit 864eb1afc60cb43e7df879b97f8ca0d719bbb735 upstream.

Clang warns when multiple pairs of parentheses are used for a single
conditional statement.

drivers/video/fbdev/sis/init301.c:851:42: warning: equality comparison
with extraneous parentheses [-Wparentheses-equality]
      } else if((SiS_Pr->SiS_IF_DEF_LVDS == 1) /* ||
                 ~~~~~~~~~~~~~~~~~~~~~~~~^~~~
drivers/video/fbdev/sis/init301.c:851:42: note: remove extraneous
parentheses around the comparison to silence this warning
      } else if((SiS_Pr->SiS_IF_DEF_LVDS == 1) /* ||
                ~                        ^   ~
drivers/video/fbdev/sis/init301.c:851:42: note: use '=' to turn this
equality comparison into an assignment
      } else if((SiS_Pr->SiS_IF_DEF_LVDS == 1) /* ||
                                         ^~
                                         =
1 warning generated.

Remove the parentheses and while we're at it, clean up the commented
code, which has been here since the beginning of git history.

Link: https://github.com/ClangBuiltLinux/linux/issues/118
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Cc: Thomas Winischhofer <thomas@winischhofer.net>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Building with LTO enabled reveals some functions whose prototypes
in the header are different from the definition:

drivers/video/fbdev/sis/sis_main.h:765:0: error: type of 'SiS_SetCH70xxANDOR' does not match original declaration [-Werror=lto-type-mismatch]
 extern void  SiS_SetCH70xxANDOR(struct SiS_Private *SiS_Pr, unsigned short reg,

drivers/video/fbdev/sis/init301.c:8937:0: note: type mismatch in parameter 4
 SiS_SetCH70xxANDOR(struct SiS_Private *SiS_Pr, unsigned short reg,

drivers/video/fbdev/sis/init301.c:8937:0: note: type 'short unsigned int' should match type 'unsigned char'
drivers/video/fbdev/sis/init301.c:8937:0: note: 'SiS_SetCH70xxANDOR' was previously declared here

The root cause appears to be the way that header files are used in this
driver, where they contain both static variable and declarations for
symbols in other files.

To clean that up, I'm changing all mixed headers to only contain
declarations the way we normally do in C, or contain only static
variables, and move the rest to a more appropriate place.  Once that
is done, the headers can be included in the other files as well, and
guarantee that the prototypes match.

There are a few headers that now only contain static variables, and
I'm leaving those alone here as the patch is already too big. These
could be trivially moved into the respective .c files.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Thomas Winischhofer <thomas@winischhofer.net>
Cc: Nicolas Pitre <nico@linaro.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: "Gustavo A. R. Silva" <gustavo@embeddedor.com>,
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.

Addresses-Coverity-ID: 115025
Addresses-Coverity-ID: 115026
Addresses-Coverity-ID: 115027
Addresses-Coverity-ID: 115028
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Cc: Thomas Winischhofer <thomas@winischhofer.net>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

Don't populate the const array specialtv on the stack, instead make it
static.  Makes the object code smaller by over 1100 bytes:

Before:
   text	   data	    bss	    dec	    hex	filename
 179899	   7504	      0	 187403	  2dc0b	drivers/video/fbdev/sis/init301.o

After:
   text	   data	    bss	    dec	    hex	filename
 178720	   7568	      0	 186288	  2d7b0	drivers/video/fbdev/sis/init301.o

(gcc version 7.2.0, x86_64)

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Cc: Thomas Winischhofer <thomas@winischhofer.net>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

Refactor code in order to avoid identical code for different branches.

This issue was detected with the help of Coccinelle.

Addresses-Coverity-ID: 1226761
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Cc: Thomas Winischhofer <thomas@winischhofer.net>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

The variables modeflag and resinfo were only assigned some value but
were never used.

Signed-off-by: Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>