On Thursday, July 26, 2018 10:17:44 PM bai wrote:
In Linux-4.16, drivers/video/fbdev/broadsheetfb.c,This is a platform driver and it won't be used on x86 (actually it is
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...
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.