On Fri, May 24, 2013 at 11:18:56AM -0400, Vivek Goyal wrote: > On Fri, May 24, 2013 at 01:29:41PM +0200, Michael Holzheu wrote: > > Currently for s390 we create the ELF core header in the 2nd kernel > > with a small trick. We relocate the addresses in the ELF header in > > a way that for the /proc/vmcore code it seems to be in the 1st kernel > > (old) memory and the read_from_oldmem() returns the correct data. > > This allows the /proc/vmcore code to use the ELF header in the > > 2nd kernel. > > > > This patch now exchanges the old mechanism with the new and much > > cleaner function call override feature that now offcially allows to > > create the ELF core header in the 2nd kernel. > > > > To use the new feature the following has to be done by the architecture > > backend code: > > > > * Override arch_get_crash_header() to return the address of the ELF > > header in new memory. > > * Override arch_free_crash_header() to free the memory of the ELF > > header in new memory. > > * Override arch_read_from_crash_header() to read from the ELF header > > in new memory > > I think above function is not clear in definition. What happens to reading > of data pointed by ELF headers. For sections of data pointed by PT_NOTE > we are calling arch_read_from_crash_header() but for accessing data > pointed by PT_LOAD, we must be calling regular functions. > > Not very sure what to do about this. Just that it looks little ugly > right now. Hi Michael, How about if we introduce another function to read notes, say arch_read_crash_notes(). So arch_read_from_crash_header() is meant to get just ELF headers (ELF header and PT_LOAD, PT_NOTE type elf headers) and arch_read_crash_notes() gets the data as pointed by PT_NOTE elf header. Thanks Vivek
