Hi Dave,
On 2017/10/10 22:50, Dave Anderson wrote:
----- Original Message -----
----- Original Message -----
Hi Dave, Hatayama-san,
These patch series fix a problem that crash cannot open a dumpfile which is
captured by "virsh dump --memory-only" or sadump on KASLR enabled kernel.
When KASLR feature is enabled, a kernel is placed on the memory randomly and
therefore crash cannot open a dumpfile because addresses of kernel symbols in
vmlinux are different from actual addresses. In the case of kdump, information
to get actual address is included in the vmcoreinfo, but dumpfile of virsh dump
or sadump does not have such a information.
Hello Takao,
Are you aware that the upstream maintainers of virsh are currently addressing the
issue by gathering and including phys_base in the ELF header and in the makedumpfile
kdump_sub_header? I haven't looked at this patch as of yet, but I worry whether
this will somehow interfere with virsh dump when it is released?
The "virsh dump --memory-only" facility will copy all of the VMCOREINFO ELF note from
kernel memory into the dumpfile, which since 4.10 includes the *value* of phys_base.
Thanks for the information. I checked patches of qemu:
http://lists.nongnu.org/archive/html/qemu-devel/2017-09/msg02657.html
Once these patches are merged, a part of my patches is not needed.
I'll update my patches and re-post only sadump part.
Thanks,
Takao Indoh
Dave
I don't know why sadump was never able to store phys_base. But I will
defer to Daisuke as to the sadump changes.
Dave
These patches calculate kaslr offset and phys_base to solve this problem.
The
basic idea is getting register (IDTR and CR3) from dump header, and
calculate
kaslr_offset/phys_base using them.
Takao Indoh (3):
Introduce x86_64_kvtop_pagetable
Fix a KASLR problem of virsh dump
Fix a KASLR problem of sadump
defs.h | 11 ++
netdump.c | 505
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
netdump.h | 1 +
sadump.c | 60 +++++++-
sadump.h | 4 +
symbols.c | 38 +++++
x86_64.c | 35 ++++-
7 files changed, 652 insertions(+), 2 deletions(-)
--
2.9.5
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