[xsrc/trunk]: xsrc/external/mit/xf86-video-wsfb/dist/src Correctly support th...

[rin <rin%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/xsrc/rev/cd77004fe056
branches:  trunk
changeset: 10368:cd77004fe056
user:      rin <rin%NetBSD.org@localhost>
date:      Tue Jul 23 12:01:53 2019 +0000

description:
Correctly support the case of fbi->fbi_fboffset != 0, which means base
address of framebuffer is not page-aligned:

- When mmap framebuffer, fbi->fbi_fboffset is added to the length of
  framebuffer. Otherwise, the last page of framebuffer is not mapped
  properly if (size of framebuffer) <= (page boundary) < (size of
  framebuffer + fbi->fbi_fboffset), since length of mapped area is
  counted from page-truncated address. This results in memory
  corruption in the upper adjacent page, or SEGV.

- Use fPtr->fbstart (real base address of framebuffer) instead of
  fPtr->fbmem (return value of mmap, i.e., page-aligned base address)
  where appropriate.

Tested on genfb(4) on Cubietruck, where fbi->fbi_fboffset = 4096.

No functional changes for majority of framebuffer drivers, whose base
address is page-aligned.

diffstat:

 external/mit/xf86-video-wsfb/dist/src/wsfb_driver.c |  36 ++++++++++----------
 1 files changed, 18 insertions(+), 18 deletions(-)

diffs (82 lines):

diff -r 47ab00024b70 -r cd77004fe056 external/mit/xf86-video-wsfb/dist/src/wsfb_driver.c
--- a/external/mit/xf86-video-wsfb/dist/src/wsfb_driver.c       Tue Jul 23 11:40:29 2019 +0000
+++ b/external/mit/xf86-video-wsfb/dist/src/wsfb_driver.c       Tue Jul 23 12:01:53 2019 +0000
@@ -505,10 +505,21 @@
                }
                fbi->fbi_flags = 0;
                fbi->fbi_fbsize = lb * info.height;
-               fbi->fbi_fboffset = 0;
-
+#ifdef WSDISPLAY_TYPE_LUNA
+               if (wstype == WSDISPLAY_TYPE_LUNA) {
+                       /*
+                        * XXX
+                        * LUNA's FB seems to have 64 dot (8 byte) offset.
+                        * This might be able to be changed in kernel
+                        * lunafb driver, but current setting was pulled
+                        * from 4.4BSD-Lite2/luna68k.
+                        */
+                       fbi->fbi_fboffset = 8;
+               } else
+#endif
+                       fbi->fbi_fboffset = 0;
        }
-       xf86Msg(X_INFO, "fboffset %x\n", fPtr->fbi.fbi_fboffset);
+       xf86Msg(X_INFO, "fboffset %x\n", (int)fPtr->fbi.fbi_fboffset);
        /*
         * Allocate room for saving the colormap.
         */
@@ -927,7 +938,7 @@
                return FALSE;
        }
        len = max(len, fPtr->fbi.fbi_fbsize);
-       fPtr->fbmem = wsfb_mmap(len, 0, fPtr->fd);
+       fPtr->fbmem = wsfb_mmap(len + fPtr->fbi.fbi_fboffset, 0, fPtr->fd);
 
        if (fPtr->fbmem == NULL) {
                xf86DrvMsg(pScrn->scrnIndex, X_ERROR,
@@ -966,17 +977,6 @@
        }
 
        fPtr->fbstart = fPtr->fbmem + fPtr->fbi.fbi_fboffset;
-#ifdef WSDISPLAY_TYPE_LUNA
-       if (wstype == WSDISPLAY_TYPE_LUNA) {
-               /*
-                * XXX
-                * LUNA's FB seems to have 64 dot (8 byte) offset.
-                * This might be able to be changed in kernel lunafb driver,
-                * but current setting was pulled from 4.4BSD-Lite2/luna68k.
-                */
-               fPtr->fbstart += 8;
-       }
-#endif
 
        if (fPtr->shadowFB) {
                fPtr->shadow = calloc(1, fPtr->fbi.fbi_stride * pScrn->virtualY);
@@ -1163,7 +1163,7 @@
 
        if (pScrn->vtSema) {
                WsfbRestore(pScrn);
-               if (munmap(fPtr->fbmem, fPtr->fbmem_len) == -1) {
+               if (munmap(fPtr->fbmem, fPtr->fbmem_len + fPtr->fbi.fbi_fboffset) == -1) {
                        xf86DrvMsg(pScrn->scrnIndex, X_ERROR,
                                   "munmap: %s\n", strerror(errno));
                }
@@ -1203,7 +1203,7 @@
                        return NULL;
                fPtr->fbi.fbi_stride = *size;
        }
-       return ((CARD8 *)fPtr->fbmem + row * fPtr->fbi.fbi_stride + offset);
+       return ((CARD8 *)fPtr->fbstart + row * fPtr->fbi.fbi_stride + offset);
 }
 
 static void
@@ -1448,7 +1448,7 @@
        }
 
        /* Clear the screen. */
-       memset(fPtr->fbmem, 0, fPtr->fbmem_len);
+       memset(fPtr->fbstart, 0, fPtr->fbmem_len);
 
        /* Restore the text mode. */
        mode = WSDISPLAYIO_MODE_EMUL;