On Fri, 16 May 2014 16:40:23 +0800 Jun Koi <junkoi2...@gmail.com> wrote: > On Fri, May 16, 2014 at 3:03 PM, Greg Kurz <gk...@linux.vnet.ibm.com> wrote: > > > On Fri, 16 May 2014 14:24:16 +0800 > > Jun Koi <junkoi2...@gmail.com> wrote: > > > Hi, > > > > > > Anybody please help me on this dump-guest-memory command? How does the > > > virtual memory map to the dumped file? > > > > > > For example, if x86 register RIP points to 0x12345, how does that map to > > > the dump file? Meaning how can I find where this address 0x12345 in the > > > dump? > > > > > > I tried, but couldnt find much documentation on this command. > > > > > > Thank you a lot, > > > Jun > > > > Hi Jun, > > > > The dump file is in ELF format and data is written in ELF notes. > > Use readelf -a on the file and you'll get something like the > > following at the end of the output: > > > > ... > > > > Notes at offset 0x000001c8 with length 0x00000328: > > Owner Data size Description > > CORE 0x00000150 NT_PRSTATUS (prstatus structure) > > QEMU 0x000001b0 Unknown note type: (0x00000000) > > > > The registers sit in the NT_PRSTATUS note (hence somewhere offset > > 0x000001c8 and 0x000001c8+0x00000150+0x14 (the latter is the ELF note > > header size). Be aware that intel is little endian: if RIP is 0x00012345, > > you need to look for '45 23 01 00' in the file. > > > > > Thanks so much, but perhaps you misunderstood my question? What I want to > know is how to map 0x12345 (virtual address) back to the dump file. >
Heh... sorry for that, morning isn't the best time to answer questions I guess ;) > For example, if 0x12345 was executing some filesystem code at the time I > dumped the VM, then I can locate exactly that code in the dumpfile, thanks > to the given RIP address (which is 0x12345 in this example) > > I hope I explain my idea clear enough this time? > Yeah. Maybe the crash utility (http://people.redhat.com/anderson) can help. > Thanks a lot, > Jun -- Gregory Kurz kurzg...@fr.ibm.com gk...@linux.vnet.ibm.com Software Engineer @ IBM/Meiosys http://www.ibm.com Tel +33 (0)562 165 496 "Anarchy is about taking complete responsibility for yourself." Alan Moore.
