Hello Pratyush, >`makedumpfile --mem-usage /proc/kcore` has been broken after kaslr specific >modifications. I have proposed a kernel patch [0] which has been ACKed by >Andrew Morton and is available in next-2017020 now. Hopefully, it should be >part of upstream in v4.10 release. This kernel patch helps to fix this >issue for both the case of kaslr enabled and disabled. > >To seek other's feedback, I am sending makedumpfile patches before kernel >patch hits upstream. Thanks for taking care of this feature. I understand that the problem is: - phys_base is necessary for VtoP, but: - SYMBOL(phys_base) is unavailable since /proc/kcore doesn't export VMCOREINFO. - get_phys_base() doesn't work well since current PT_LOAD doesn't have valid p_paddr. The new makedumpfile with this patches can show unexpected behavior since it will refer to invalid p_paddr(always 0). Of course, also current makedumpfile cannot work if phys_base isn't 0. If we don't have any way to get phys_base in 1st kernel environment, I think we should disable this feature in older kernel (e.g. by checking kernel version). Thanks, Atsushi Kumagai >[0] >http://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git/commit/?h=next-20170206&id=c9d4e5d7b7fd6c74e134ca44d >f8a5386efbc561c > >Baoquan He (2): > makedumpfile: Correct the calculation of kvaddr in > set_kcore_vmcoreinfo > makedumpfile: Discard process_dump_load > >Pratyush Anand (4): > show_mem_usage(): calculate page offset after elf load > initial(): call cach_init() a bit early > x86_64: check physical address in PT_LOAD for none direct mapped > regions > elf_info: kcore: check for invalid physical address > > arch/x86_64.c | 6 ++++-- > elf_info.c | 25 +++++-------------------- > makedumpfile.c | 12 ++++++------ > 3 files changed, 15 insertions(+), 28 deletions(-) > >-- >2.9.3 > > >_______________________________________________ >kexec mailing list >kexec at lists.infradead.org >http://lists.infradead.org/mailman/listinfo/kexec
