Hi On Sat, Mar 15, 2014 at 12:29 PM, Conor O <falling174fps@xxxxxxxxx> wrote: > Hello all, I hope this is a reasonable place to post a bug. If I fix > it I can post a fix too. > > I believe there might be a bug in deferred io. In my fb driver I have > a block of memory, allocated with kmalloc, that I can mmap, write to, > and munmap perfectly fine using my own mmap routine. As soon as I > switch to deferred io, there's a problem: > > From userspace, I can mmap the framebuffer memory fine and write to > it. The deferred io driver routine is called and updates the display > perfectly correctly. As soon as I call munmap() I get a repeated > kernel messages. This happens on ARM but not under an Ubuntu > Virtualbox VM (x86): You map kmalloc()ed memory to user-space? How do you guarantee that it's page-aligned? How do you protect kernel-internal state? This sounds really odd. Anyhow, you really need to post a link to the code in question if you want people to help you. Thanks David -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
