On Sun, 2014-01-26 at 14:39 +0100, Fubo Chen wrote: > On Sun, Jan 26, 2014 at 11:54 AM, Jose Alonso <joalon...@gmail.com> wrote: > > I observed that there are for_each macros that do an extra memory access > > beyond the defined area. > > Normally this does not cause problems. > > But, this can cause exceptions. For example: if the area is allocated at > > the end of a page and the next page is not accessible. > > > > For correctness, I suggest changing the arguments of the 'for loop' like > > others 'for_each' do in the kernel. > > Does this patch fix a kernel crash when using gcc 4.8 like the patch > in http://lkml.org/lkml/2014/1/21/146 ?
The patch for 'for_each_isci_host' is equivalent. I followed the link above, and as I understand: The access to to_pci_info(pdev)->hosts[2] do not caused exception, but the fact of hosts[2] is "logically accessed" "confused" the gcc 4.8 compiler. (The gcc compiler do very aggressive loop optimization and can eliminate loops executing each pass linearly). -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
