On Tue, 2016-11-10 at 07:47:56 UTC, Nicholas Piggin wrote: > On Mon, 10 Oct 2016 07:15:11 -0700 > Guenter Roeck <li...@roeck-us.net> wrote: > > > On 10/09/2016 10:49 PM, Nicholas Piggin wrote: > > > On Sun, 9 Oct 2016 08:21:21 -0700 > > > Guenter Roeck <li...@roeck-us.net> wrote: > > > > > >> Nicholas, > > >> > > >> some of my qemu tests for ppc64 started failing on mainline (and -next). > > >> You can find a test log at > > >> http://kerneltests.org/builders/qemu-ppc64-master/builds/580/steps/qemubuildcommand/logs/stdio > > >> > > >> The scripts to run the test are available at > > >> https://github.com/groeck/linux-build-test/tree/master/rootfs/ppc64 > > >> > > >> Bisect points to commit f9aa67142ef26 ("powerpc/64s: Consolidate > > >> Alignment 0x600 > > >> interrupt"). Bisect log is attached. > > >> > > >> Since I don't have the means to run the code on a real system, I have no > > >> idea > > >> if the problem is caused by qemu or by the code. It is interesting, > > >> though, that > > >> only the 'mac99' tests are affected. > > >> > > >> Please let me know if there is anything I can do to help tracking down > > >> the > > >> problem. > > > > > > Thanks for this. That patch just moves a small amount of code, so it's > > > likely > > > that it's caused something to get placed out of range of its caller, or > > > the > > > linker started generating a stub for some reason. I can't immediately see > > > the > > > problem, but it could be specific to your exact toolchain. > > > > > > Something that might help, would you be able to put the compiled vmlinux > > > binaries > > > from before/after the bad patch somewhere I can grab them? > > > > > > > http://server.roeck-us.net/qemu/ppc64/mac99/ > > > > 'bad' is at f9aa67142ef26, 'good' is one commit earlier, 'tot' is from top > > of tree > > (b66484cd7470, more specifically). > > > > Key difference in System.map, from the bad case: > > > > c000000000005c00 T __end_interrupts > > c000000000007000 t end_virt_trampolines > > c000000000008000 t 00000010.long_branch.power4_fixup_nap+0 > > c000000000008100 t fs_label > > c000000000008100 t start_text > > > > 00000010.long_branch.power4_fixup_nap+0 does not exist in the good case, > > and fs_label/start_text are at c000000000008000. > > > > Toolchain is from poky 1.5.1, which uses gcc 4.8.1 and binutils 2.23.2. > > I also tried with the toolchain from poky 1.6, using gcc 4.8.2 and binutils > > 2.24, > > with the same result. > > Thank you for the quick response, this points to the exact problem. > I've attached a patch which should fix the bug. There are some checks > I've got planned that will catch this type of thing at build time and > be much easier to track down. > > Thanks, > Nick > > From: Nicholas Piggin <npig...@gmail.com> > Date: Tue, 11 Oct 2016 18:33:26 +1100 > Subject: [PATCH] powerpc/64s: fix power4_fixup_nap placement > > power4_fixup_nap is called from the "common" handlers, not the virt/real > handlers, therefore it should itself be a common handler. Placing it > down in the trampoline space caused it to go out of reach of its > callers, requiring a trampoline inserted at the start of the text > section, which breaks the fixed section address calculations. > > Reported-by: Guenter Roeck <li...@roeck-us.net> > Signed-off-by: Nicholas Piggin <npig...@gmail.com>
Applied to powerpc next, thanks. https://git.kernel.org/powerpc/c/7c8cb4b50f3cc6f4a8f7bfddad6fb5 cheers
