On Wed, Aug 17, 2016 at 12:18:08PM -0700, Andrew Morton wrote: > On Wed, 17 Aug 2016 17:10:28 +0100 Catalin Marinas <catalin.marinas@xxxxxxx> wrote: > > On Wed, Aug 17, 2016 at 11:51:41PM +0800, kernel test robot wrote: > > > FYI, we noticed the following commit: > > > > > > https://github.com/0day-ci/linux Catalin-Marinas/mm-kmemleak-Avoid-using-__va-on-addresses-that-don-t-have-a-lowmem-mapping/20160816-232733 > > > commit 122708b1b91eb3d253baf86a263ead0f1f5cac78 ("mm: kmemleak: Avoid using __va() on addresses that don't have a lowmem mapping") > > > > > > in testcase: boot > > > > > > on test machine: 1 threads qemu-system-i386 -enable-kvm with 320M memory > > > > > > caused below changes: > > > > > > +--------------------------------+------------+------------+ > > > | | 304bec1b1d | 122708b1b9 | > > > +--------------------------------+------------+------------+ > > > | boot_successes | 3 | 0 | > > > | boot_failures | 5 | 8 | > > > | invoked_oom-killer:gfp_mask=0x | 1 | | > > > | Mem-Info | 1 | | > > > | BUG:kernel_test_crashed | 4 | | > > > | PANIC:early_exception | 0 | 8 | > > > | EIP_is_at__phys_addr | 0 | 8 | > > > | BUG:kernel_hang_in_boot_stage | 0 | 2 | > > > | BUG:kernel_boot_hang | 0 | 6 | > > > +--------------------------------+------------+------------+ > > > > Please disregard this patch. I posted v2 here: > > > > http://lkml.kernel.org/g/1471426130-21330-1-git-send-email-catalin.marinas@xxxxxxx > > > > (and I'm eager to see the kbuild/kernel test robot results ;)) > > I don't see how the v1->v2 changes could fix a panic? This particular panic is avoided (rather than fixed) in v2 because the config used above has kmemleak disabled, hence there is no __pa(high_memory) call. But you are right, it is likely to trigger once kmemleak is enabled, I think because __pa(high_memory) use isn't valid. I need to reproduce it tomorrow (UK time) but a workaround is to test against __pa(high_memory - 1) or (max_low_pfn << PAGE_SHIFT). -- Catalin -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>