src/patches/suse-2.6.27.31/patches.fixes/kdump-x86-sparsemem.diff

   1 From e7706fc691513b0f06adb3de3d6ac04293180146 Mon Sep 17 00:00:00 2001
   2 From: Ken'ichi Ohmichi <oomichi@mxs.nes.nec.co.jp>
   3 Date: Mon, 20 Oct 2008 13:51:52 +0900
   4 Subject: [PATCH] x86, kdump: fix invalid access on i386 sparsemem
   5 References: bnc#440525
   6
   7 Impact: fix kdump crash on 32-bit sparsemem kernels
   8
   9 Since linux-2.6.27, kdump has failed on i386 sparsemem kernel.
  10 1st-kernel gets a panic just before switching to 2nd-kernel.
  11
  12 The cause is that a kernel accesses invalid mem_section by
  13 page_to_pfn(image->swap_page) at machine_kexec().
  14 image->swap_page is allocated if kexec for hibernation, but
  15 it is not allocated if kdump. So if kdump, a kernel should
  16 not access the mem_section corresponding to image->swap_page.
  17
  18 The attached patch fixes this invalid access.
  19
  20 Signed-off-by: Ken'ichi Ohmichi <oomichi@mxs.nes.nec.co.jp>
  21 Cc: kexec-ml <kexec@lists.infradead.org>
  22 Cc: Andrew Morton <akpm@linux-foundation.org>
  23 Signed-off-by: Ingo Molnar <mingo@elte.hu>
  24 Acked-by: Bernhard Walle <bwalle@suse.de>
  25
  26 diff --git a/arch/x86/kernel/machine_kexec_32.c b/arch/x86/kernel/machine_kexec_32.c
  27 index 0732adb..7a38574 100644
  28 --- a/arch/x86/kernel/machine_kexec_32.c
  29 +++ b/arch/x86/kernel/machine_kexec_32.c
  30 @@ -162,7 +162,10 @@ void machine_kexec(struct kimage *image)
  31         page_list[VA_PTE_0] = (unsigned long)kexec_pte0;
  32         page_list[PA_PTE_1] = __pa(kexec_pte1);
  33         page_list[VA_PTE_1] = (unsigned long)kexec_pte1;
  34 -       page_list[PA_SWAP_PAGE] = (page_to_pfn(image->swap_page) << PAGE_SHIFT);
  35 +
  36 +       if (image->type == KEXEC_TYPE_DEFAULT)
  37 +               page_list[PA_SWAP_PAGE] = (page_to_pfn(image->swap_page)
  38 +                                               << PAGE_SHIFT);
  39
  40         /* The segment registers are funny things, they have both a
  41          * visible and an invisible part.  Whenever the visible part is