On Wed, 2005-03-09 at 07:17 -0700, Eric W. Biederman wrote: > Vivek Goyal <[EMAIL PROTECTED]> writes: > > > On Tue, 2005-03-08 at 11:00 -0700, Eric W. Biederman wrote: > > That sounds good. But we loose the advantage of doing limited debugging > > with gdb. Crash (or other analysis tools) will still take considerable > > amount of time before before they are fully ready and tested. > > > > How about giving user the flexibility to choose. What I mean is > > introducing a command line option in kexec-tools to choose between ELF32 > > and ELF64 headers. For the users who are not using PAE systems, they can > > very well go with ELF32 headers and do the debugging using gdb. > > > > This also requires, setting the kernel virtual addresses while preparing > > the headers. KVA for linearly mapped region is known in advance and can > > be filled at header creation time and gdb can directly operate upon this > > region. > > I have no problems decorating the ELF header you are generating > in user space with virtual addresses assuming we can reliably > get that information. And before a kernel crashes looks like a reasonable > time to ask that question. I don't currently see where you could > derive that information.
I want to fill the virtual addresses of linearly mapped region. That is physical addresses from 0 to MAXMEM (896 MB) are mapped by kernel at virtual addresses PAGE_OFFSET to (PAGE_OFFSET + MAXMEM). Values of PAGE_OFFSET and MAXMEM are already known and hard-coded. I think I used the terminology kernel virtual address and that is adding to the confusion. Kernel virtual addresses are not necessarily linearly mapped. What I meant was kernel logical addresses whose associated physical addresses differ only by a constant offset. > > Beyond that I prefer a little command line tool that will do the > ELF64 to ELF32 conversion and possibly add in the kva mapping to > make the core dump usable with gdb. Doing it in a separate tool > means it is the developer who is doing the analysis who cares > not the user who is capturing the system core dump. > > But I do agree that it a use case worth solving. > > Eric > - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
