>Hi Atsushi, > >Thanks for the testing. > >On Wednesday 10 May 2017 01:37 PM, Atsushi Kumagai wrote: >>> Hi Atsushi, >>> >>> On Friday 28 April 2017 12:22 PM, Atsushi Kumagai wrote: >>>> Hello Pratyush, >>>> >>>> Thanks for your report, I have received this. >>>> I'm on vacation until Mar 8, I'll review it when I return from vacation. >>> >>> Any further comment on it? >>> Otherwise, I will send a v2 after accommodating concern from Xunlei. >> >> Unfortunately, it doesn't seem like I can make time anymore for review this week, >> but at least this patch doesn't seem to work in my environment (linux 4.8 without kaslr). >> Do you have any ideas ? > >I see, why it would have caused. I have not tested this case, but I hope my v2 >should not have this issue. Umm, v2 still doesn't work in my environment... It seems that I have to investigate this deeper. $ cat scrub.conf [vmlinux] erase modules size 50 $ (gdb) r -cd31 -x vmlinux --config scrub.conf vmcore dumpfile.cd31 Starting program: /work/kdump_utils/makedumpfile/makedumpfile -cd31 -x vmlinux --config scrub.conf vmcore dumpfile.cd31 warning: no loadable sections found in added symbol-file system-supplied DSO at 0x7ffff7ffd000 [Thread debugging using libthread_db enabled] Program received signal SIGSEGV, Segmentation fault. 0x000000308366ee0d in fseek () from /lib64/libc.so.6 Missing separate debuginfos, use: debuginfo-install bzip2-libs-1.0.5-7.el6_0.x86_64 elfutils-libelf-0.152-1.el6.x86_64 elfutils-libs-0.152-1.el6.x86_64 glibc-2.12-1.132.el6.x86_64 libgcc-4.4.7-4.el6.x86_64 libstdc++-4.4.7-4.el6.x86_64 snappy-1.1.0-1.el6.x86_64 xz-libs-4.999.9-0.3.beta.20091007git.el6.x86_64 zlib-1.2.3-29.el6.x86_64 (gdb) bt #0 0x000000308366ee0d in fseek () from /lib64/libc.so.6 #1 0x0000000000420937 in get_kaslr_offset_x86_64 (vaddr=18446744071589596288) at arch/x86_64.c:43 #2 0x0000000000414310 in resolve_config_entry (ce=0x701370, base_vaddr=<value optimized out>, base_struct_name=0x0) at erase_info.c:1091 #3 0x0000000000415a89 in get_config_symbol_addr (filter_symbol=0x701370, size_symbol=0x701430) at erase_info.c:1264 #4 update_filter_info (filter_symbol=0x701370, size_symbol=0x701430) at erase_info.c:1579 #5 0x0000000000416543 in process_config (name_config=<value optimized out>) at erase_info.c:1789 #6 process_config_file (name_config=<value optimized out>) at erase_info.c:1862 #7 0x0000000000417c57 in gather_filter_info () at erase_info.c:2356 #8 0x0000000000443e5b in create_dumpfile () at makedumpfile.c:9870 #9 0x00000000004457ae in main (argc=<value optimized out>, argv=<value optimized out>) at makedumpfile.c:11349 (gdb) Thanks, Atsushi Kuamgai >~Pratyush >> >> >> Program received signal SIGSEGV, Segmentation fault. >> 0x00007ffff6be49f5 in fseek () from /lib64/libc.so.6 >> Missing separate debuginfos, use: debuginfo-install bzip2-libs-1.0.6-13.el7.x86_64 elfutils-libelf-0.163-3.el7.x86_64 >elfutils-libs-0.163-3.el7.x86_64 glibc-2.17-105.el7.x86_64 libgcc-4.8.5-4.el7.x86_64 libstdc++-4.8.5-4.el7.x86_64 >snappy-1.1.0-3.el7.x86_64 xz-libs-5.1.2-12alpha.el7.x86_64 zlib-1.2.7-15.el7.x86_64 >> (gdb) bt >> #0 0x00007ffff6be49f5 in fseek () from /lib64/libc.so.6 >> #1 0x0000000000429d38 in read_vmcoreinfo_symbol (str_symbol=0x44cb0c "SYMBOL(_stext)=") at makedumpfile.c:2384 >> #2 0x000000000042097a in get_kaslr_offset_x86_64 (vaddr=18446744071589596288) at arch/x86_64.c:45 >> #3 0x0000000000414310 in resolve_config_entry (ce=0x701370, base_vaddr=<optimized out>, base_struct_name=0x0) >> at erase_info.c:1091 >> #4 0x0000000000415a89 in get_config_symbol_addr (base_struct_name=0x0, base_vaddr=0, ce=0x701370) at erase_info.c:1264 >> #5 update_filter_info (filter_symbol=0x701370, size_symbol=0x701430) at erase_info.c:1579 >> #6 0x0000000000416543 in process_config (config=<optimized out>) at erase_info.c:1789 >> #7 process_config_file (name_config=<optimized out>) at erase_info.c:1862 >> #8 0x0000000000417c57 in gather_filter_info () at erase_info.c:2356 >> #9 0x0000000000443ccb in create_dumpfile () at makedumpfile.c:9863 >> #10 0x000000000044561e in main (argc=<optimized out>, argv=<optimized out>) at makedumpfile.c:11342 >> (gdb) >> >> >> Thanks, >> Atsushi Kumagai >> >>> ~Pratyush >>> >>> >>>> >>>> Thanks, >>>> Atsushi Kumagai >>>> >>>>> 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 >>
