Usually we can use gdb to debug the running kernel like this: gdb vmlinux /proc/kcore However now it doesn't work any more since those kernel symbols are got at compiling time, while kaslr-ed kernel do relocation on them. Don't know if this will impact anything else. On 04/27/17 at 11:45am, Pratyush Anand wrote: > Hi All, > > We came across another failure in makedumpfile when kaslr is enabled. This > failure occurs when we try re-filtering. We try to erase some symbol from a > dumpfile which was copied/compressed from /proc/vmcore using makedumpfile. > > We have very limited symbol information in vmcoreinfo. So symbols to be > erased may not be available in vmcoreinfo and we look for it in vmlinux. > However, symbol address from vmlinux is a static address which differs > from run time address with KASLR_OFFSET. Therefore, reading any "virtual > address of vmlinux" from vmcore is not possible. > > These patches finds runtime KASLR offset and then calculates run time > address of symbols read from vmlinux. > > Since, I am not an expert of x86, and these patches touch x86 part of > makedumpfile, therefore I have CCed x86 experts. Please, provide your > review comment and let me know if you think there could have been a better > way to resolve this issue. > > thanks > > ~Pratyush > > Pratyush Anand (2): > makedumpfile: add runtime kaslr offset if it exists > x86_64: calculate page_offset in case of re-filtering > > arch/x86_64.c | 45 +++++++++++++++++++++++++++++++++++++++++++-- > erase_info.c | 1 + > makedumpfile.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ > makedumpfile.h | 15 +++++++++++++++ > 4 files changed, 103 insertions(+), 2 deletions(-) > > -- > 2.9.3 > > > _______________________________________________ > kexec mailing list > kexec at lists.infradead.org > http://lists.infradead.org/mailman/listinfo/kexec
