Re: [Crash-utility] [PATCH 0/3] Fix KASLR problem on virsh dump and sadump

----- 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?

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 > > > -- > Crash-utility mailing list > Crash-utility(a)redhat.com > https://www.redhat.com/mailman/listinfo/crash-utility > -- Crash-utility mailing list Crash-utility(a)redhat.com https://www.redhat.com/mailman/listinfo/crash-utility