On Wed, May 29, 2013 at 07:12:49PM +0200, Michael Holzheu wrote: [..] > > > > So are you saying that s390 is ready to switch to mechanism of > > > > creating ELF headers in first kernel by kexec-tools and new kernel > > > > does not have to preare ELF headers? > > > > > > No, I meant that currently nobody is using the kexec tools ELF > > > header creation in the 1st kernel on s390. We create the ELF header > > > in the 2nd kernel (mainly because of our cpuplugd issue). > > > > > > Therefore, I think, we can safely change the ELF header creation in > > > 2nd kernel to use your p_offset swap trick *and* we remove the swap > > > code in the copy_oldmem_page() implementation (same kernel). > > > > Ok. Got it. So s390 can fix it in kernel without creating any backward > > compatibility issues (given the fact that nobody sees to be using > > kexec-tools to build headers). > > > > So please go ahead and fix it and that should solve your mmap() issue > > too. Also please fix kexec-tools and that change will not be backward > > compatible. > > Ok, I will do this. > > I think we should add this "swap in ELF header" patch to the "kdump: > Allow ELF header creation in new kernel" patch series (on top of the > mmap patch series). Because when I remove the swap code from > copy_oldmem_page(), the old trick to access the ELF header in the first > kernel memory will no longer work. > > Is that ok for you? I am fine with both the patches in same series. Thanks Vivek
