When an application accesses a mapped frame buffer backed by deferred I/O, it receives a segmentation fault. Fix this by removing the check for VM_IO in do_page_fault(). Signed-off-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> --- This check was never present in a fault handler on any other architecture than m68k. Some digging revealed that it was added in v2.1.106, but I couldn't find an email with a patch adding it. That same kernel version extended the use of the hwreg_present() helper to HP9000/300, so the check might have been needed there, perhaps only during development? The Atari kernel relies heavily on hwreg_present() (both the success and failure cases), and these still work, at least on ARAnyM. --- arch/m68k/mm/fault.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/arch/m68k/mm/fault.c b/arch/m68k/mm/fault.c index 1493cf5eac1e7a39..71aa9f6315dc8028 100644 --- a/arch/m68k/mm/fault.c +++ b/arch/m68k/mm/fault.c @@ -93,8 +93,6 @@ int do_page_fault(struct pt_regs *regs, unsigned long address, vma = find_vma(mm, address); if (!vma) goto map_err; - if (vma->vm_flags & VM_IO) - goto acc_err; if (vma->vm_start <= address) goto good_area; if (!(vma->vm_flags & VM_GROWSDOWN)) -- 2.25.1
