Hello, I am trying to determine all the ways/methods in which the kernel will modify its own .text section after the machine has booted. I am working with the latest Fedora kernel (3.5.2-3.fc17.x86_64). So far I have identified: 1) smp_locks 2) .alt_instructions - although from writing a script to parse the alt_instr structures, it seems these may not affect .text, any clarification on this would be greatly appreciated. 3) dynamic ftracing (related to mcount) 4) I also see where the paravirt instructions (PVOP_CALL4) seems to compile as absolute call instructions, but then become relative calls at runtime. I figured this one out this by diffing the disassembly of xen_cpuid_base in both memory and from the vmlinux after noticing they were not the same: # diff xen_cpuid_base-memory xen_cpuid_base-disk 20,21c20 < 0000003C E8A2E5A3FF call dword 0xffffffffffa3e5e3 < 00000041 6690 xchg ax,ax ---
0000003C FF142580DCC181 call qword [0xffffffff81c1dc80]
and the 0xffffffff81c1dc80 instruction relates to the cpuid function which ends up in paravirt code. Any clarifications or links to docs on this changing of the calls in the paravirt subsystem would be helpful. I also would like to find out if the kernel changes itself in any other way besides those that I have listed. Thanks, Andrew