From 22b45144f67dbaf0705992dc1462de2813fb83a1 Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Thu, 26 Jun 2008 12:02:49 -0700 Subject: [PATCH] x86/paravirt: groundwork for 64-bit Xen support, fix #2 Ingo Molnar wrote: > that fixed the build but now we've got a boot crash with this config: > > time.c: Detected 2010.304 MHz processor. > spurious 8259A interrupt: IRQ7. > BUG: unable to handle kernel NULL pointer dereference at 0000000000000000 > IP: [<0000000000000000>] > PGD 0 > Thread overran stack, or stack corrupted > Oops: 0010 [1] SMP > CPU 0 > I don't know if this will fix this bug, but it's definitely a bugfix. It was trashing random pages by overwriting them with pagetables... Don't trash a large pmd's data when mapping physical memory. This is a bugfix for "x86_64: adjust mapping of physical pagetables to work with Xen". Signed-off-by: Jeremy Fitzhardinge Cc: xen-devel Cc: Stephen Tweedie Cc: Eduardo Habkost Cc: Mark McLoughlin Cc: Vegard Nossum Cc: Nick Piggin Cc: Yinghai Lu Signed-off-by: Ingo Molnar --- arch/x86/mm/init_64.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index 5c3305e050..b10b7f17ea 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -320,7 +320,8 @@ phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end) } if (pmd_val(*pmd)) { - phys_pte_update(pmd, address, end); + if (!pmd_large(*pmd)) + phys_pte_update(pmd, address, end); continue; } -- 2.39.5