• Ken'ichi Ohmichi's avatar
    vmcoreinfo: add the symbol "phys_base" · 629c8b4c
    Ken'ichi Ohmichi authored
    
    
    Fix the problem that makedumpfile sometimes fails on x86_64 machine.
    
    This patch adds the symbol "phys_base" to a vmcoreinfo data.  The
    vmcoreinfo data has the minimum debugging information only for dump
    filtering.  makedumpfile (dump filtering command) gets it to distinguish
    unnecessary pages, and makedumpfile creates a small dumpfile.
    
    On x86_64 kernel which compiled with CONFIG_PHYSICAL_START=0x0 and
    CONFIG_RELOCATABLE=y, makedumpfile fails like the following:
    
     # makedumpfile -d31 /proc/vmcore dumpfile
     The kernel version is not supported.
     The created dumpfile may be incomplete.
     _exclude_free_page: Can't get next online node.
    
     makedumpfile Failed.
     #
    
    The cause is the lack of the symbol "phys_base" in a vmcoreinfo data.
    If the symbol "phys_base" does not exist, makedumpfile considers an
    x86_64 kernel as non relocatable.  As the result, makedumpfile
    misunderstands the physical address where the kernel is loaded, and it
    cannot translate a kernel virtual address to physical address correctly.
    
    To fix this problem, this patch adds the symbol "phys_base" to a
    vmcoreinfo data.
    
    Signed-off-by: default avatarKen'ichi Ohmichi <oomichi@mxs.nes.nec.co.jp>
    Cc: "Eric W. Biederman" <ebiederm@xmission.com>
    Cc: <stable@kernel.org>
    Acked-by: default avatarVivek Goyal <vgoyal@redhat.com>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    629c8b4c