On Fri, Mar 28, 2014 at 10:05:22AM -0400, Vivek Goyal wrote: > On Fri, Mar 28, 2014 at 03:05:00PM +0800, WANG Chao wrote: > > When kASLR is enabled (CONFIG_RANDOMIZED_BASE=y), kernel text mapping > > base is randomized. The max base offset of such randomization is > > configured at compile time through CONFIG_RANDOMIZE_MAX_BASE_OFFSET (by > > default 1G). > > > > Currently kexec-tools is using hard code macro X86_64__START_KERNEL_map > > (0xffffffff80000000) and X86_64_KERNEL_TEXT_SIZE (512M) to determine > > kernel text mapping from kcore's PT_LOAD. With kASLR, the mapping is > > changed as the following: > > > > ffffffff80000000 - (ffffffff80000000+CONFIG_RANDOMIZE_BASE_MAX_OFFSET) > > > > As Vivek suggested, we can get _stext kernel symbol address from > > /proc/kallsyms, and search for kcore's PT_LOAD which contains _stext, > > and we can say that this area represents the kernel mapping area. > > > > Let's first use this way to find out kernel text mapping. If failed for > > whatever reason, fall back to use the old way. > > > > Suggested-by: Vivek Goyal <vgoyal at redhat.com> > > Signed-off-by: WANG Chao <chaowang at redhat.com> > > Looks good to me. > > Acked-by: Vivek Goyal <vgoyal at redhat.com> Thanks, applied.
